OpenCloudOS-Kernel/drivers/net/can/flexcan.c

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// SPDX-License-Identifier: GPL-2.0
//
// flexcan.c - FLEXCAN CAN controller driver
//
// Copyright (c) 2005-2006 Varma Electronics Oy
// Copyright (c) 2009 Sascha Hauer, Pengutronix
// Copyright (c) 2010-2017 Pengutronix, Marc Kleine-Budde <kernel@pengutronix.de>
// Copyright (c) 2014 David Jander, Protonic Holland
//
// Based on code originally by Andrey Volkov <avolkov@varma-el.com>
#include <linux/netdevice.h>
#include <linux/can.h>
#include <linux/can/dev.h>
#include <linux/can/error.h>
#include <linux/can/led.h>
#include <linux/can/rx-offload.h>
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/regulator/consumer.h>
#include <linux/regmap.h>
#define DRV_NAME "flexcan"
/* 8 for RX fifo and 2 error handling */
#define FLEXCAN_NAPI_WEIGHT (8 + 2)
/* FLEXCAN module configuration register (CANMCR) bits */
#define FLEXCAN_MCR_MDIS BIT(31)
#define FLEXCAN_MCR_FRZ BIT(30)
#define FLEXCAN_MCR_FEN BIT(29)
#define FLEXCAN_MCR_HALT BIT(28)
#define FLEXCAN_MCR_NOT_RDY BIT(27)
#define FLEXCAN_MCR_WAK_MSK BIT(26)
#define FLEXCAN_MCR_SOFTRST BIT(25)
#define FLEXCAN_MCR_FRZ_ACK BIT(24)
#define FLEXCAN_MCR_SUPV BIT(23)
#define FLEXCAN_MCR_SLF_WAK BIT(22)
#define FLEXCAN_MCR_WRN_EN BIT(21)
#define FLEXCAN_MCR_LPM_ACK BIT(20)
#define FLEXCAN_MCR_WAK_SRC BIT(19)
#define FLEXCAN_MCR_DOZE BIT(18)
#define FLEXCAN_MCR_SRX_DIS BIT(17)
#define FLEXCAN_MCR_IRMQ BIT(16)
#define FLEXCAN_MCR_LPRIO_EN BIT(13)
#define FLEXCAN_MCR_AEN BIT(12)
/* MCR_MAXMB: maximum used MBs is MAXMB + 1 */
#define FLEXCAN_MCR_MAXMB(x) ((x) & 0x7f)
#define FLEXCAN_MCR_IDAM_A (0x0 << 8)
#define FLEXCAN_MCR_IDAM_B (0x1 << 8)
#define FLEXCAN_MCR_IDAM_C (0x2 << 8)
#define FLEXCAN_MCR_IDAM_D (0x3 << 8)
/* FLEXCAN control register (CANCTRL) bits */
#define FLEXCAN_CTRL_PRESDIV(x) (((x) & 0xff) << 24)
#define FLEXCAN_CTRL_RJW(x) (((x) & 0x03) << 22)
#define FLEXCAN_CTRL_PSEG1(x) (((x) & 0x07) << 19)
#define FLEXCAN_CTRL_PSEG2(x) (((x) & 0x07) << 16)
#define FLEXCAN_CTRL_BOFF_MSK BIT(15)
#define FLEXCAN_CTRL_ERR_MSK BIT(14)
#define FLEXCAN_CTRL_CLK_SRC BIT(13)
#define FLEXCAN_CTRL_LPB BIT(12)
#define FLEXCAN_CTRL_TWRN_MSK BIT(11)
#define FLEXCAN_CTRL_RWRN_MSK BIT(10)
#define FLEXCAN_CTRL_SMP BIT(7)
#define FLEXCAN_CTRL_BOFF_REC BIT(6)
#define FLEXCAN_CTRL_TSYN BIT(5)
#define FLEXCAN_CTRL_LBUF BIT(4)
#define FLEXCAN_CTRL_LOM BIT(3)
#define FLEXCAN_CTRL_PROPSEG(x) ((x) & 0x07)
#define FLEXCAN_CTRL_ERR_BUS (FLEXCAN_CTRL_ERR_MSK)
#define FLEXCAN_CTRL_ERR_STATE \
(FLEXCAN_CTRL_TWRN_MSK | FLEXCAN_CTRL_RWRN_MSK | \
FLEXCAN_CTRL_BOFF_MSK)
#define FLEXCAN_CTRL_ERR_ALL \
(FLEXCAN_CTRL_ERR_BUS | FLEXCAN_CTRL_ERR_STATE)
/* FLEXCAN control register 2 (CTRL2) bits */
#define FLEXCAN_CTRL2_ECRWRE BIT(29)
#define FLEXCAN_CTRL2_WRMFRZ BIT(28)
#define FLEXCAN_CTRL2_RFFN(x) (((x) & 0x0f) << 24)
#define FLEXCAN_CTRL2_TASD(x) (((x) & 0x1f) << 19)
#define FLEXCAN_CTRL2_MRP BIT(18)
#define FLEXCAN_CTRL2_RRS BIT(17)
#define FLEXCAN_CTRL2_EACEN BIT(16)
/* FLEXCAN memory error control register (MECR) bits */
#define FLEXCAN_MECR_ECRWRDIS BIT(31)
#define FLEXCAN_MECR_HANCEI_MSK BIT(19)
#define FLEXCAN_MECR_FANCEI_MSK BIT(18)
#define FLEXCAN_MECR_CEI_MSK BIT(16)
#define FLEXCAN_MECR_HAERRIE BIT(15)
#define FLEXCAN_MECR_FAERRIE BIT(14)
#define FLEXCAN_MECR_EXTERRIE BIT(13)
#define FLEXCAN_MECR_RERRDIS BIT(9)
#define FLEXCAN_MECR_ECCDIS BIT(8)
#define FLEXCAN_MECR_NCEFAFRZ BIT(7)
/* FLEXCAN error and status register (ESR) bits */
#define FLEXCAN_ESR_TWRN_INT BIT(17)
#define FLEXCAN_ESR_RWRN_INT BIT(16)
#define FLEXCAN_ESR_BIT1_ERR BIT(15)
#define FLEXCAN_ESR_BIT0_ERR BIT(14)
#define FLEXCAN_ESR_ACK_ERR BIT(13)
#define FLEXCAN_ESR_CRC_ERR BIT(12)
#define FLEXCAN_ESR_FRM_ERR BIT(11)
#define FLEXCAN_ESR_STF_ERR BIT(10)
#define FLEXCAN_ESR_TX_WRN BIT(9)
#define FLEXCAN_ESR_RX_WRN BIT(8)
#define FLEXCAN_ESR_IDLE BIT(7)
#define FLEXCAN_ESR_TXRX BIT(6)
#define FLEXCAN_EST_FLT_CONF_SHIFT (4)
#define FLEXCAN_ESR_FLT_CONF_MASK (0x3 << FLEXCAN_EST_FLT_CONF_SHIFT)
#define FLEXCAN_ESR_FLT_CONF_ACTIVE (0x0 << FLEXCAN_EST_FLT_CONF_SHIFT)
#define FLEXCAN_ESR_FLT_CONF_PASSIVE (0x1 << FLEXCAN_EST_FLT_CONF_SHIFT)
#define FLEXCAN_ESR_BOFF_INT BIT(2)
#define FLEXCAN_ESR_ERR_INT BIT(1)
#define FLEXCAN_ESR_WAK_INT BIT(0)
#define FLEXCAN_ESR_ERR_BUS \
(FLEXCAN_ESR_BIT1_ERR | FLEXCAN_ESR_BIT0_ERR | \
FLEXCAN_ESR_ACK_ERR | FLEXCAN_ESR_CRC_ERR | \
FLEXCAN_ESR_FRM_ERR | FLEXCAN_ESR_STF_ERR)
#define FLEXCAN_ESR_ERR_STATE \
(FLEXCAN_ESR_TWRN_INT | FLEXCAN_ESR_RWRN_INT | FLEXCAN_ESR_BOFF_INT)
#define FLEXCAN_ESR_ERR_ALL \
(FLEXCAN_ESR_ERR_BUS | FLEXCAN_ESR_ERR_STATE)
#define FLEXCAN_ESR_ALL_INT \
(FLEXCAN_ESR_TWRN_INT | FLEXCAN_ESR_RWRN_INT | \
FLEXCAN_ESR_BOFF_INT | FLEXCAN_ESR_ERR_INT | \
FLEXCAN_ESR_WAK_INT)
/* FLEXCAN interrupt flag register (IFLAG) bits */
/* Errata ERR005829 step7: Reserve first valid MB */
can: flexcan: Always use last mailbox for TX Essentially this patch moves the TX mailbox to position 63, regardless of timestamp based offloading or RX FIFO. So mainly the iflag register usage regarding TX has changed. The rest is consolidating RX FIFO and timestamp offloading as they now use both the same TX mailbox. The reason is a very annoying behavior regarding sending RTR frames when _not_ using RX FIFO: If a TX mailbox sent a RTR frame it becomes a RX mailbox. For that reason flexcan_irq disables the TX mailbox again. But if during the time the RTR was sent and the TX mailbox is disabled a new CAN frames is received, it is lost without notice. The reason is that so-called "Move-in" process starts from the lowest mailbox which happen to be a TX mailbox set to EMPTY. Steps to reproduce (I used an imx7d): 1. generate regular bursts of messages 2. send a RTR from flexcan with higher priority than burst messages every 1ms, e.g. cangen -I 0x100 -L 0 -g 1 -R can0 3. notice a lost message without notification after some seconds When running an iperf in parallel this problem is occurring even more frequently. Using filters is not possible as at least one single CAN-ID is allowed. Handling the TX MB during RX is also not possible as there is no race-free disable of RX MB. There is still a slight window when the described problem can occur. But for that all RX MB must be in use which is essentially next to an overrun. Still there will be no indication if it ever occurs. Signed-off-by: Alexander Stein <alexander.stein@systec-electronic.com> Cc: linux-stable <stable@vger.kernel.org> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2018-10-11 23:01:25 +08:00
#define FLEXCAN_TX_MB_RESERVED_OFF_FIFO 8
#define FLEXCAN_TX_MB_RESERVED_OFF_TIMESTAMP 0
can: flexcan: Always use last mailbox for TX Essentially this patch moves the TX mailbox to position 63, regardless of timestamp based offloading or RX FIFO. So mainly the iflag register usage regarding TX has changed. The rest is consolidating RX FIFO and timestamp offloading as they now use both the same TX mailbox. The reason is a very annoying behavior regarding sending RTR frames when _not_ using RX FIFO: If a TX mailbox sent a RTR frame it becomes a RX mailbox. For that reason flexcan_irq disables the TX mailbox again. But if during the time the RTR was sent and the TX mailbox is disabled a new CAN frames is received, it is lost without notice. The reason is that so-called "Move-in" process starts from the lowest mailbox which happen to be a TX mailbox set to EMPTY. Steps to reproduce (I used an imx7d): 1. generate regular bursts of messages 2. send a RTR from flexcan with higher priority than burst messages every 1ms, e.g. cangen -I 0x100 -L 0 -g 1 -R can0 3. notice a lost message without notification after some seconds When running an iperf in parallel this problem is occurring even more frequently. Using filters is not possible as at least one single CAN-ID is allowed. Handling the TX MB during RX is also not possible as there is no race-free disable of RX MB. There is still a slight window when the described problem can occur. But for that all RX MB must be in use which is essentially next to an overrun. Still there will be no indication if it ever occurs. Signed-off-by: Alexander Stein <alexander.stein@systec-electronic.com> Cc: linux-stable <stable@vger.kernel.org> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2018-10-11 23:01:25 +08:00
#define FLEXCAN_RX_MB_OFF_TIMESTAMP_FIRST (FLEXCAN_TX_MB_RESERVED_OFF_TIMESTAMP + 1)
#define FLEXCAN_IFLAG_MB(x) BIT_ULL(x)
#define FLEXCAN_IFLAG2_MB(x) BIT((x) & 0x1f)
#define FLEXCAN_IFLAG_RX_FIFO_OVERFLOW BIT(7)
#define FLEXCAN_IFLAG_RX_FIFO_WARN BIT(6)
#define FLEXCAN_IFLAG_RX_FIFO_AVAILABLE BIT(5)
/* FLEXCAN message buffers */
#define FLEXCAN_MB_CODE_MASK (0xf << 24)
#define FLEXCAN_MB_CODE_RX_BUSY_BIT (0x1 << 24)
#define FLEXCAN_MB_CODE_RX_INACTIVE (0x0 << 24)
#define FLEXCAN_MB_CODE_RX_EMPTY (0x4 << 24)
#define FLEXCAN_MB_CODE_RX_FULL (0x2 << 24)
#define FLEXCAN_MB_CODE_RX_OVERRUN (0x6 << 24)
#define FLEXCAN_MB_CODE_RX_RANSWER (0xa << 24)
#define FLEXCAN_MB_CODE_TX_INACTIVE (0x8 << 24)
#define FLEXCAN_MB_CODE_TX_ABORT (0x9 << 24)
#define FLEXCAN_MB_CODE_TX_DATA (0xc << 24)
#define FLEXCAN_MB_CODE_TX_TANSWER (0xe << 24)
#define FLEXCAN_MB_CNT_SRR BIT(22)
#define FLEXCAN_MB_CNT_IDE BIT(21)
#define FLEXCAN_MB_CNT_RTR BIT(20)
#define FLEXCAN_MB_CNT_LENGTH(x) (((x) & 0xf) << 16)
#define FLEXCAN_MB_CNT_TIMESTAMP(x) ((x) & 0xffff)
#define FLEXCAN_TIMEOUT_US (250)
/* FLEXCAN hardware feature flags
*
* Below is some version info we got:
can: flexcan: implement error passive state quirk Add FLEXCAN_QUIRK_BROKEN_PERR_STATE for better description of the missing error passive interrupt quirk. Error interrupt flooding may happen if the broken error state quirk fix is enabled. For example, in case there is singled out node on the bus and the node sends a frame, then error interrupt flooding happens and will not stop because the node cannot go to bus off. The flooding will stop after another node connected to the bus again. If high bitrate configured on the low end system, then the flooding may causes performance issue, hence, this patch mitigates this by: 1. disable error interrupt upon error passive state transition 2. re-enable error interrupt upon error warning state transition 3. disable/enable error interrupt upon error active state transition depends on FLEXCAN_QUIRK_BROKEN_WERR_STATE In this way, the driver is still able to report correct state transitions without additional latency. When there are bus problems, flooding of error interrupts is limited to the number of frames required to change state from error warning to error passive if the core has [TR]WRN_INT connected (FLEXCAN_QUIRK_BROKEN_WERR_STATE is not enabled), otherwise, the flooding is limited to the number of frames required to change state from error active to error passive. Signed-off-by: Zhu Yi <yi.zhu5@cn.bosch.com> Signed-off-by: Mark Jonas <mark.jonas@de.bosch.com> Acked-by: Wolfgang Grandegger <wg@grandegger.com> Cc: linux-stable <stable@vger.kernel.org> # >= v4.11 Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2017-09-15 15:03:58 +08:00
* SOC Version IP-Version Glitch- [TR]WRN_INT IRQ Err Memory err RTR re-
* Filter? connected? Passive detection ception in MB
* MX25 FlexCAN2 03.00.00.00 no no no no no
can: flexcan: implement error passive state quirk Add FLEXCAN_QUIRK_BROKEN_PERR_STATE for better description of the missing error passive interrupt quirk. Error interrupt flooding may happen if the broken error state quirk fix is enabled. For example, in case there is singled out node on the bus and the node sends a frame, then error interrupt flooding happens and will not stop because the node cannot go to bus off. The flooding will stop after another node connected to the bus again. If high bitrate configured on the low end system, then the flooding may causes performance issue, hence, this patch mitigates this by: 1. disable error interrupt upon error passive state transition 2. re-enable error interrupt upon error warning state transition 3. disable/enable error interrupt upon error active state transition depends on FLEXCAN_QUIRK_BROKEN_WERR_STATE In this way, the driver is still able to report correct state transitions without additional latency. When there are bus problems, flooding of error interrupts is limited to the number of frames required to change state from error warning to error passive if the core has [TR]WRN_INT connected (FLEXCAN_QUIRK_BROKEN_WERR_STATE is not enabled), otherwise, the flooding is limited to the number of frames required to change state from error active to error passive. Signed-off-by: Zhu Yi <yi.zhu5@cn.bosch.com> Signed-off-by: Mark Jonas <mark.jonas@de.bosch.com> Acked-by: Wolfgang Grandegger <wg@grandegger.com> Cc: linux-stable <stable@vger.kernel.org> # >= v4.11 Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2017-09-15 15:03:58 +08:00
* MX28 FlexCAN2 03.00.04.00 yes yes no no no
* MX35 FlexCAN2 03.00.00.00 no no no no no
can: flexcan: implement error passive state quirk Add FLEXCAN_QUIRK_BROKEN_PERR_STATE for better description of the missing error passive interrupt quirk. Error interrupt flooding may happen if the broken error state quirk fix is enabled. For example, in case there is singled out node on the bus and the node sends a frame, then error interrupt flooding happens and will not stop because the node cannot go to bus off. The flooding will stop after another node connected to the bus again. If high bitrate configured on the low end system, then the flooding may causes performance issue, hence, this patch mitigates this by: 1. disable error interrupt upon error passive state transition 2. re-enable error interrupt upon error warning state transition 3. disable/enable error interrupt upon error active state transition depends on FLEXCAN_QUIRK_BROKEN_WERR_STATE In this way, the driver is still able to report correct state transitions without additional latency. When there are bus problems, flooding of error interrupts is limited to the number of frames required to change state from error warning to error passive if the core has [TR]WRN_INT connected (FLEXCAN_QUIRK_BROKEN_WERR_STATE is not enabled), otherwise, the flooding is limited to the number of frames required to change state from error active to error passive. Signed-off-by: Zhu Yi <yi.zhu5@cn.bosch.com> Signed-off-by: Mark Jonas <mark.jonas@de.bosch.com> Acked-by: Wolfgang Grandegger <wg@grandegger.com> Cc: linux-stable <stable@vger.kernel.org> # >= v4.11 Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2017-09-15 15:03:58 +08:00
* MX53 FlexCAN2 03.00.00.00 yes no no no no
* MX6s FlexCAN3 10.00.12.00 yes yes no no yes
* VF610 FlexCAN3 ? no yes no yes yes?
* LS1021A FlexCAN2 03.00.04.00 no yes no no yes
*
* Some SOCs do not have the RX_WARN & TX_WARN interrupt line connected.
*/
#define FLEXCAN_QUIRK_BROKEN_WERR_STATE BIT(1) /* [TR]WRN_INT not connected */
#define FLEXCAN_QUIRK_DISABLE_RXFG BIT(2) /* Disable RX FIFO Global mask */
#define FLEXCAN_QUIRK_ENABLE_EACEN_RRS BIT(3) /* Enable EACEN and RRS bit in ctrl2 */
#define FLEXCAN_QUIRK_DISABLE_MECR BIT(4) /* Disable Memory error detection */
#define FLEXCAN_QUIRK_USE_OFF_TIMESTAMP BIT(5) /* Use timestamp based offloading */
can: flexcan: implement error passive state quirk Add FLEXCAN_QUIRK_BROKEN_PERR_STATE for better description of the missing error passive interrupt quirk. Error interrupt flooding may happen if the broken error state quirk fix is enabled. For example, in case there is singled out node on the bus and the node sends a frame, then error interrupt flooding happens and will not stop because the node cannot go to bus off. The flooding will stop after another node connected to the bus again. If high bitrate configured on the low end system, then the flooding may causes performance issue, hence, this patch mitigates this by: 1. disable error interrupt upon error passive state transition 2. re-enable error interrupt upon error warning state transition 3. disable/enable error interrupt upon error active state transition depends on FLEXCAN_QUIRK_BROKEN_WERR_STATE In this way, the driver is still able to report correct state transitions without additional latency. When there are bus problems, flooding of error interrupts is limited to the number of frames required to change state from error warning to error passive if the core has [TR]WRN_INT connected (FLEXCAN_QUIRK_BROKEN_WERR_STATE is not enabled), otherwise, the flooding is limited to the number of frames required to change state from error active to error passive. Signed-off-by: Zhu Yi <yi.zhu5@cn.bosch.com> Signed-off-by: Mark Jonas <mark.jonas@de.bosch.com> Acked-by: Wolfgang Grandegger <wg@grandegger.com> Cc: linux-stable <stable@vger.kernel.org> # >= v4.11 Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2017-09-15 15:03:58 +08:00
#define FLEXCAN_QUIRK_BROKEN_PERR_STATE BIT(6) /* No interrupt for error passive */
#define FLEXCAN_QUIRK_DEFAULT_BIG_ENDIAN BIT(7) /* default to BE register access */
#define FLEXCAN_QUIRK_SETUP_STOP_MODE BIT(8) /* Setup stop mode to support wakeup */
/* Structure of the message buffer */
struct flexcan_mb {
u32 can_ctrl;
u32 can_id;
u32 data[];
};
/* Structure of the hardware registers */
struct flexcan_regs {
u32 mcr; /* 0x00 */
u32 ctrl; /* 0x04 */
u32 timer; /* 0x08 */
u32 _reserved1; /* 0x0c */
u32 rxgmask; /* 0x10 */
u32 rx14mask; /* 0x14 */
u32 rx15mask; /* 0x18 */
u32 ecr; /* 0x1c */
u32 esr; /* 0x20 */
u32 imask2; /* 0x24 */
u32 imask1; /* 0x28 */
u32 iflag2; /* 0x2c */
u32 iflag1; /* 0x30 */
union { /* 0x34 */
u32 gfwr_mx28; /* MX28, MX53 */
u32 ctrl2; /* MX6, VF610 */
};
u32 esr2; /* 0x38 */
u32 imeur; /* 0x3c */
u32 lrfr; /* 0x40 */
u32 crcr; /* 0x44 */
u32 rxfgmask; /* 0x48 */
u32 rxfir; /* 0x4c */
u32 _reserved3[12]; /* 0x50 */
u8 mb[2][512]; /* 0x80 */
/* FIFO-mode:
* MB
* 0x080...0x08f 0 RX message buffer
* 0x090...0x0df 1-5 reserverd
* 0x0e0...0x0ff 6-7 8 entry ID table
* (mx25, mx28, mx35, mx53)
* 0x0e0...0x2df 6-7..37 8..128 entry ID table
* size conf'ed via ctrl2::RFFN
* (mx6, vf610)
*/
u32 _reserved4[256]; /* 0x480 */
u32 rximr[64]; /* 0x880 */
u32 _reserved5[24]; /* 0x980 */
u32 gfwr_mx6; /* 0x9e0 - MX6 */
u32 _reserved6[63]; /* 0x9e4 */
u32 mecr; /* 0xae0 */
u32 erriar; /* 0xae4 */
u32 erridpr; /* 0xae8 */
u32 errippr; /* 0xaec */
u32 rerrar; /* 0xaf0 */
u32 rerrdr; /* 0xaf4 */
u32 rerrsynr; /* 0xaf8 */
u32 errsr; /* 0xafc */
};
struct flexcan_devtype_data {
u32 quirks; /* quirks needed for different IP cores */
};
struct flexcan_stop_mode {
struct regmap *gpr;
u8 req_gpr;
u8 req_bit;
u8 ack_gpr;
u8 ack_bit;
};
struct flexcan_priv {
struct can_priv can;
struct can_rx_offload offload;
struct device *dev;
struct flexcan_regs __iomem *regs;
struct flexcan_mb __iomem *tx_mb;
struct flexcan_mb __iomem *tx_mb_reserved;
u8 tx_mb_idx;
u8 mb_count;
u8 mb_size;
u8 clk_src; /* clock source of CAN Protocol Engine */
u64 rx_mask;
u32 reg_ctrl_default;
struct clk *clk_ipg;
struct clk *clk_per;
const struct flexcan_devtype_data *devtype_data;
struct regulator *reg_xceiver;
struct flexcan_stop_mode stm;
/* Read and Write APIs */
u32 (*read)(void __iomem *addr);
void (*write)(u32 val, void __iomem *addr);
};
static const struct flexcan_devtype_data fsl_p1010_devtype_data = {
.quirks = FLEXCAN_QUIRK_BROKEN_WERR_STATE |
FLEXCAN_QUIRK_BROKEN_PERR_STATE |
FLEXCAN_QUIRK_DEFAULT_BIG_ENDIAN,
};
static const struct flexcan_devtype_data fsl_imx25_devtype_data = {
.quirks = FLEXCAN_QUIRK_BROKEN_WERR_STATE |
FLEXCAN_QUIRK_BROKEN_PERR_STATE,
};
static const struct flexcan_devtype_data fsl_imx28_devtype_data = {
.quirks = FLEXCAN_QUIRK_BROKEN_PERR_STATE,
};
static const struct flexcan_devtype_data fsl_imx6q_devtype_data = {
.quirks = FLEXCAN_QUIRK_DISABLE_RXFG | FLEXCAN_QUIRK_ENABLE_EACEN_RRS |
FLEXCAN_QUIRK_USE_OFF_TIMESTAMP | FLEXCAN_QUIRK_BROKEN_PERR_STATE |
FLEXCAN_QUIRK_SETUP_STOP_MODE,
};
static const struct flexcan_devtype_data fsl_vf610_devtype_data = {
.quirks = FLEXCAN_QUIRK_DISABLE_RXFG | FLEXCAN_QUIRK_ENABLE_EACEN_RRS |
FLEXCAN_QUIRK_DISABLE_MECR | FLEXCAN_QUIRK_USE_OFF_TIMESTAMP |
FLEXCAN_QUIRK_BROKEN_PERR_STATE,
};
static const struct flexcan_devtype_data fsl_ls1021a_r2_devtype_data = {
.quirks = FLEXCAN_QUIRK_DISABLE_RXFG | FLEXCAN_QUIRK_ENABLE_EACEN_RRS |
FLEXCAN_QUIRK_DISABLE_MECR | FLEXCAN_QUIRK_BROKEN_PERR_STATE |
FLEXCAN_QUIRK_USE_OFF_TIMESTAMP,
};
static const struct can_bittiming_const flexcan_bittiming_const = {
.name = DRV_NAME,
.tseg1_min = 4,
.tseg1_max = 16,
.tseg2_min = 2,
.tseg2_max = 8,
.sjw_max = 4,
.brp_min = 1,
.brp_max = 256,
.brp_inc = 1,
};
/* FlexCAN module is essentially modelled as a little-endian IP in most
* SoCs, i.e the registers as well as the message buffer areas are
* implemented in a little-endian fashion.
*
* However there are some SoCs (e.g. LS1021A) which implement the FlexCAN
* module in a big-endian fashion (i.e the registers as well as the
* message buffer areas are implemented in a big-endian way).
*
* In addition, the FlexCAN module can be found on SoCs having ARM or
* PPC cores. So, we need to abstract off the register read/write
* functions, ensuring that these cater to all the combinations of module
* endianness and underlying CPU endianness.
*/
static inline u32 flexcan_read_be(void __iomem *addr)
{
return ioread32be(addr);
}
static inline void flexcan_write_be(u32 val, void __iomem *addr)
{
iowrite32be(val, addr);
}
static inline u32 flexcan_read_le(void __iomem *addr)
{
return ioread32(addr);
}
static inline void flexcan_write_le(u32 val, void __iomem *addr)
{
iowrite32(val, addr);
}
static struct flexcan_mb __iomem *flexcan_get_mb(const struct flexcan_priv *priv,
u8 mb_index)
{
u8 bank_size;
bool bank;
if (WARN_ON(mb_index >= priv->mb_count))
return NULL;
bank_size = sizeof(priv->regs->mb[0]) / priv->mb_size;
bank = mb_index >= bank_size;
if (bank)
mb_index -= bank_size;
return (struct flexcan_mb __iomem *)
(&priv->regs->mb[bank][priv->mb_size * mb_index]);
}
static void flexcan_enable_wakeup_irq(struct flexcan_priv *priv, bool enable)
{
struct flexcan_regs __iomem *regs = priv->regs;
u32 reg_mcr;
reg_mcr = priv->read(&regs->mcr);
if (enable)
reg_mcr |= FLEXCAN_MCR_WAK_MSK;
else
reg_mcr &= ~FLEXCAN_MCR_WAK_MSK;
priv->write(reg_mcr, &regs->mcr);
}
static inline int flexcan_enter_stop_mode(struct flexcan_priv *priv)
{
struct flexcan_regs __iomem *regs = priv->regs;
unsigned int ackval;
u32 reg_mcr;
reg_mcr = priv->read(&regs->mcr);
reg_mcr |= FLEXCAN_MCR_SLF_WAK;
priv->write(reg_mcr, &regs->mcr);
/* enable stop request */
regmap_update_bits(priv->stm.gpr, priv->stm.req_gpr,
1 << priv->stm.req_bit, 1 << priv->stm.req_bit);
/* get stop acknowledgment */
if (regmap_read_poll_timeout(priv->stm.gpr, priv->stm.ack_gpr,
ackval, ackval & (1 << priv->stm.ack_bit),
0, FLEXCAN_TIMEOUT_US))
return -ETIMEDOUT;
return 0;
}
static inline int flexcan_exit_stop_mode(struct flexcan_priv *priv)
{
struct flexcan_regs __iomem *regs = priv->regs;
unsigned int ackval;
u32 reg_mcr;
/* remove stop request */
regmap_update_bits(priv->stm.gpr, priv->stm.req_gpr,
1 << priv->stm.req_bit, 0);
/* get stop acknowledgment */
if (regmap_read_poll_timeout(priv->stm.gpr, priv->stm.ack_gpr,
ackval, !(ackval & (1 << priv->stm.ack_bit)),
0, FLEXCAN_TIMEOUT_US))
return -ETIMEDOUT;
reg_mcr = priv->read(&regs->mcr);
reg_mcr &= ~FLEXCAN_MCR_SLF_WAK;
priv->write(reg_mcr, &regs->mcr);
return 0;
}
can: flexcan: implement error passive state quirk Add FLEXCAN_QUIRK_BROKEN_PERR_STATE for better description of the missing error passive interrupt quirk. Error interrupt flooding may happen if the broken error state quirk fix is enabled. For example, in case there is singled out node on the bus and the node sends a frame, then error interrupt flooding happens and will not stop because the node cannot go to bus off. The flooding will stop after another node connected to the bus again. If high bitrate configured on the low end system, then the flooding may causes performance issue, hence, this patch mitigates this by: 1. disable error interrupt upon error passive state transition 2. re-enable error interrupt upon error warning state transition 3. disable/enable error interrupt upon error active state transition depends on FLEXCAN_QUIRK_BROKEN_WERR_STATE In this way, the driver is still able to report correct state transitions without additional latency. When there are bus problems, flooding of error interrupts is limited to the number of frames required to change state from error warning to error passive if the core has [TR]WRN_INT connected (FLEXCAN_QUIRK_BROKEN_WERR_STATE is not enabled), otherwise, the flooding is limited to the number of frames required to change state from error active to error passive. Signed-off-by: Zhu Yi <yi.zhu5@cn.bosch.com> Signed-off-by: Mark Jonas <mark.jonas@de.bosch.com> Acked-by: Wolfgang Grandegger <wg@grandegger.com> Cc: linux-stable <stable@vger.kernel.org> # >= v4.11 Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2017-09-15 15:03:58 +08:00
static inline void flexcan_error_irq_enable(const struct flexcan_priv *priv)
{
struct flexcan_regs __iomem *regs = priv->regs;
u32 reg_ctrl = (priv->reg_ctrl_default | FLEXCAN_CTRL_ERR_MSK);
priv->write(reg_ctrl, &regs->ctrl);
can: flexcan: implement error passive state quirk Add FLEXCAN_QUIRK_BROKEN_PERR_STATE for better description of the missing error passive interrupt quirk. Error interrupt flooding may happen if the broken error state quirk fix is enabled. For example, in case there is singled out node on the bus and the node sends a frame, then error interrupt flooding happens and will not stop because the node cannot go to bus off. The flooding will stop after another node connected to the bus again. If high bitrate configured on the low end system, then the flooding may causes performance issue, hence, this patch mitigates this by: 1. disable error interrupt upon error passive state transition 2. re-enable error interrupt upon error warning state transition 3. disable/enable error interrupt upon error active state transition depends on FLEXCAN_QUIRK_BROKEN_WERR_STATE In this way, the driver is still able to report correct state transitions without additional latency. When there are bus problems, flooding of error interrupts is limited to the number of frames required to change state from error warning to error passive if the core has [TR]WRN_INT connected (FLEXCAN_QUIRK_BROKEN_WERR_STATE is not enabled), otherwise, the flooding is limited to the number of frames required to change state from error active to error passive. Signed-off-by: Zhu Yi <yi.zhu5@cn.bosch.com> Signed-off-by: Mark Jonas <mark.jonas@de.bosch.com> Acked-by: Wolfgang Grandegger <wg@grandegger.com> Cc: linux-stable <stable@vger.kernel.org> # >= v4.11 Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2017-09-15 15:03:58 +08:00
}
static inline void flexcan_error_irq_disable(const struct flexcan_priv *priv)
{
struct flexcan_regs __iomem *regs = priv->regs;
u32 reg_ctrl = (priv->reg_ctrl_default & ~FLEXCAN_CTRL_ERR_MSK);
priv->write(reg_ctrl, &regs->ctrl);
can: flexcan: implement error passive state quirk Add FLEXCAN_QUIRK_BROKEN_PERR_STATE for better description of the missing error passive interrupt quirk. Error interrupt flooding may happen if the broken error state quirk fix is enabled. For example, in case there is singled out node on the bus and the node sends a frame, then error interrupt flooding happens and will not stop because the node cannot go to bus off. The flooding will stop after another node connected to the bus again. If high bitrate configured on the low end system, then the flooding may causes performance issue, hence, this patch mitigates this by: 1. disable error interrupt upon error passive state transition 2. re-enable error interrupt upon error warning state transition 3. disable/enable error interrupt upon error active state transition depends on FLEXCAN_QUIRK_BROKEN_WERR_STATE In this way, the driver is still able to report correct state transitions without additional latency. When there are bus problems, flooding of error interrupts is limited to the number of frames required to change state from error warning to error passive if the core has [TR]WRN_INT connected (FLEXCAN_QUIRK_BROKEN_WERR_STATE is not enabled), otherwise, the flooding is limited to the number of frames required to change state from error active to error passive. Signed-off-by: Zhu Yi <yi.zhu5@cn.bosch.com> Signed-off-by: Mark Jonas <mark.jonas@de.bosch.com> Acked-by: Wolfgang Grandegger <wg@grandegger.com> Cc: linux-stable <stable@vger.kernel.org> # >= v4.11 Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2017-09-15 15:03:58 +08:00
}
static int flexcan_clks_enable(const struct flexcan_priv *priv)
{
int err;
err = clk_prepare_enable(priv->clk_ipg);
if (err)
return err;
err = clk_prepare_enable(priv->clk_per);
if (err)
clk_disable_unprepare(priv->clk_ipg);
return err;
}
static void flexcan_clks_disable(const struct flexcan_priv *priv)
{
clk_disable_unprepare(priv->clk_per);
clk_disable_unprepare(priv->clk_ipg);
}
static inline int flexcan_transceiver_enable(const struct flexcan_priv *priv)
{
if (!priv->reg_xceiver)
return 0;
return regulator_enable(priv->reg_xceiver);
}
static inline int flexcan_transceiver_disable(const struct flexcan_priv *priv)
{
if (!priv->reg_xceiver)
return 0;
return regulator_disable(priv->reg_xceiver);
}
static int flexcan_chip_enable(struct flexcan_priv *priv)
{
struct flexcan_regs __iomem *regs = priv->regs;
unsigned int timeout = FLEXCAN_TIMEOUT_US / 10;
u32 reg;
reg = priv->read(&regs->mcr);
reg &= ~FLEXCAN_MCR_MDIS;
priv->write(reg, &regs->mcr);
while (timeout-- && (priv->read(&regs->mcr) & FLEXCAN_MCR_LPM_ACK))
udelay(10);
if (priv->read(&regs->mcr) & FLEXCAN_MCR_LPM_ACK)
return -ETIMEDOUT;
return 0;
}
static int flexcan_chip_disable(struct flexcan_priv *priv)
{
struct flexcan_regs __iomem *regs = priv->regs;
unsigned int timeout = FLEXCAN_TIMEOUT_US / 10;
u32 reg;
reg = priv->read(&regs->mcr);
reg |= FLEXCAN_MCR_MDIS;
priv->write(reg, &regs->mcr);
while (timeout-- && !(priv->read(&regs->mcr) & FLEXCAN_MCR_LPM_ACK))
udelay(10);
if (!(priv->read(&regs->mcr) & FLEXCAN_MCR_LPM_ACK))
return -ETIMEDOUT;
return 0;
}
static int flexcan_chip_freeze(struct flexcan_priv *priv)
{
struct flexcan_regs __iomem *regs = priv->regs;
unsigned int timeout = 1000 * 1000 * 10 / priv->can.bittiming.bitrate;
u32 reg;
reg = priv->read(&regs->mcr);
reg |= FLEXCAN_MCR_HALT;
priv->write(reg, &regs->mcr);
while (timeout-- && !(priv->read(&regs->mcr) & FLEXCAN_MCR_FRZ_ACK))
udelay(100);
if (!(priv->read(&regs->mcr) & FLEXCAN_MCR_FRZ_ACK))
return -ETIMEDOUT;
return 0;
}
static int flexcan_chip_unfreeze(struct flexcan_priv *priv)
{
struct flexcan_regs __iomem *regs = priv->regs;
unsigned int timeout = FLEXCAN_TIMEOUT_US / 10;
u32 reg;
reg = priv->read(&regs->mcr);
reg &= ~FLEXCAN_MCR_HALT;
priv->write(reg, &regs->mcr);
while (timeout-- && (priv->read(&regs->mcr) & FLEXCAN_MCR_FRZ_ACK))
udelay(10);
if (priv->read(&regs->mcr) & FLEXCAN_MCR_FRZ_ACK)
return -ETIMEDOUT;
return 0;
}
static int flexcan_chip_softreset(struct flexcan_priv *priv)
{
struct flexcan_regs __iomem *regs = priv->regs;
unsigned int timeout = FLEXCAN_TIMEOUT_US / 10;
priv->write(FLEXCAN_MCR_SOFTRST, &regs->mcr);
while (timeout-- && (priv->read(&regs->mcr) & FLEXCAN_MCR_SOFTRST))
udelay(10);
if (priv->read(&regs->mcr) & FLEXCAN_MCR_SOFTRST)
return -ETIMEDOUT;
return 0;
}
static int __flexcan_get_berr_counter(const struct net_device *dev,
struct can_berr_counter *bec)
{
const struct flexcan_priv *priv = netdev_priv(dev);
struct flexcan_regs __iomem *regs = priv->regs;
u32 reg = priv->read(&regs->ecr);
bec->txerr = (reg >> 0) & 0xff;
bec->rxerr = (reg >> 8) & 0xff;
return 0;
}
static int flexcan_get_berr_counter(const struct net_device *dev,
struct can_berr_counter *bec)
{
const struct flexcan_priv *priv = netdev_priv(dev);
int err;
err = pm_runtime_get_sync(priv->dev);
if (err < 0)
return err;
err = __flexcan_get_berr_counter(dev, bec);
pm_runtime_put(priv->dev);
return err;
}
static netdev_tx_t flexcan_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
const struct flexcan_priv *priv = netdev_priv(dev);
struct can_frame *cf = (struct can_frame *)skb->data;
u32 can_id;
u32 data;
u32 ctrl = FLEXCAN_MB_CODE_TX_DATA | (cf->can_dlc << 16);
int i;
if (can_dropped_invalid_skb(dev, skb))
return NETDEV_TX_OK;
netif_stop_queue(dev);
if (cf->can_id & CAN_EFF_FLAG) {
can_id = cf->can_id & CAN_EFF_MASK;
ctrl |= FLEXCAN_MB_CNT_IDE | FLEXCAN_MB_CNT_SRR;
} else {
can_id = (cf->can_id & CAN_SFF_MASK) << 18;
}
if (cf->can_id & CAN_RTR_FLAG)
ctrl |= FLEXCAN_MB_CNT_RTR;
for (i = 0; i < cf->can_dlc; i += sizeof(u32)) {
data = be32_to_cpup((__be32 *)&cf->data[i]);
priv->write(data, &priv->tx_mb->data[i / sizeof(u32)]);
}
can_put_echo_skb(skb, dev, 0);
priv->write(can_id, &priv->tx_mb->can_id);
priv->write(ctrl, &priv->tx_mb->can_ctrl);
/* Errata ERR005829 step8:
* Write twice INACTIVE(0x8) code to first MB.
*/
priv->write(FLEXCAN_MB_CODE_TX_INACTIVE,
&priv->tx_mb_reserved->can_ctrl);
priv->write(FLEXCAN_MB_CODE_TX_INACTIVE,
&priv->tx_mb_reserved->can_ctrl);
return NETDEV_TX_OK;
}
static void flexcan_irq_bus_err(struct net_device *dev, u32 reg_esr)
{
struct flexcan_priv *priv = netdev_priv(dev);
struct flexcan_regs __iomem *regs = priv->regs;
struct sk_buff *skb;
struct can_frame *cf;
bool rx_errors = false, tx_errors = false;
u32 timestamp;
int err;
timestamp = priv->read(&regs->timer) << 16;
skb = alloc_can_err_skb(dev, &cf);
if (unlikely(!skb))
return;
cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
if (reg_esr & FLEXCAN_ESR_BIT1_ERR) {
netdev_dbg(dev, "BIT1_ERR irq\n");
cf->data[2] |= CAN_ERR_PROT_BIT1;
tx_errors = true;
}
if (reg_esr & FLEXCAN_ESR_BIT0_ERR) {
netdev_dbg(dev, "BIT0_ERR irq\n");
cf->data[2] |= CAN_ERR_PROT_BIT0;
tx_errors = true;
}
if (reg_esr & FLEXCAN_ESR_ACK_ERR) {
netdev_dbg(dev, "ACK_ERR irq\n");
cf->can_id |= CAN_ERR_ACK;
cf->data[3] = CAN_ERR_PROT_LOC_ACK;
tx_errors = true;
}
if (reg_esr & FLEXCAN_ESR_CRC_ERR) {
netdev_dbg(dev, "CRC_ERR irq\n");
cf->data[2] |= CAN_ERR_PROT_BIT;
cf->data[3] = CAN_ERR_PROT_LOC_CRC_SEQ;
rx_errors = true;
}
if (reg_esr & FLEXCAN_ESR_FRM_ERR) {
netdev_dbg(dev, "FRM_ERR irq\n");
cf->data[2] |= CAN_ERR_PROT_FORM;
rx_errors = true;
}
if (reg_esr & FLEXCAN_ESR_STF_ERR) {
netdev_dbg(dev, "STF_ERR irq\n");
cf->data[2] |= CAN_ERR_PROT_STUFF;
rx_errors = true;
}
priv->can.can_stats.bus_error++;
if (rx_errors)
dev->stats.rx_errors++;
if (tx_errors)
dev->stats.tx_errors++;
err = can_rx_offload_queue_sorted(&priv->offload, skb, timestamp);
if (err)
dev->stats.rx_fifo_errors++;
}
static void flexcan_irq_state(struct net_device *dev, u32 reg_esr)
{
struct flexcan_priv *priv = netdev_priv(dev);
struct flexcan_regs __iomem *regs = priv->regs;
struct sk_buff *skb;
struct can_frame *cf;
enum can_state new_state, rx_state, tx_state;
int flt;
struct can_berr_counter bec;
u32 timestamp;
int err;
flt = reg_esr & FLEXCAN_ESR_FLT_CONF_MASK;
if (likely(flt == FLEXCAN_ESR_FLT_CONF_ACTIVE)) {
tx_state = unlikely(reg_esr & FLEXCAN_ESR_TX_WRN) ?
CAN_STATE_ERROR_WARNING : CAN_STATE_ERROR_ACTIVE;
rx_state = unlikely(reg_esr & FLEXCAN_ESR_RX_WRN) ?
CAN_STATE_ERROR_WARNING : CAN_STATE_ERROR_ACTIVE;
new_state = max(tx_state, rx_state);
} else {
__flexcan_get_berr_counter(dev, &bec);
new_state = flt == FLEXCAN_ESR_FLT_CONF_PASSIVE ?
CAN_STATE_ERROR_PASSIVE : CAN_STATE_BUS_OFF;
rx_state = bec.rxerr >= bec.txerr ? new_state : 0;
tx_state = bec.rxerr <= bec.txerr ? new_state : 0;
}
/* state hasn't changed */
if (likely(new_state == priv->can.state))
return;
timestamp = priv->read(&regs->timer) << 16;
skb = alloc_can_err_skb(dev, &cf);
if (unlikely(!skb))
return;
can_change_state(dev, cf, tx_state, rx_state);
if (unlikely(new_state == CAN_STATE_BUS_OFF))
can_bus_off(dev);
err = can_rx_offload_queue_sorted(&priv->offload, skb, timestamp);
if (err)
dev->stats.rx_fifo_errors++;
}
static inline struct flexcan_priv *rx_offload_to_priv(struct can_rx_offload *offload)
{
return container_of(offload, struct flexcan_priv, offload);
}
static struct sk_buff *flexcan_mailbox_read(struct can_rx_offload *offload,
unsigned int n, u32 *timestamp,
bool drop)
{
struct flexcan_priv *priv = rx_offload_to_priv(offload);
struct flexcan_regs __iomem *regs = priv->regs;
struct flexcan_mb __iomem *mb;
struct sk_buff *skb;
struct can_frame *cf;
u32 reg_ctrl, reg_id, reg_iflag1;
int i;
if (unlikely(drop)) {
skb = ERR_PTR(-ENOBUFS);
goto mark_as_read;
}
mb = flexcan_get_mb(priv, n);
if (priv->devtype_data->quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP) {
u32 code;
do {
reg_ctrl = priv->read(&mb->can_ctrl);
} while (reg_ctrl & FLEXCAN_MB_CODE_RX_BUSY_BIT);
/* is this MB empty? */
code = reg_ctrl & FLEXCAN_MB_CODE_MASK;
if ((code != FLEXCAN_MB_CODE_RX_FULL) &&
(code != FLEXCAN_MB_CODE_RX_OVERRUN))
return NULL;
if (code == FLEXCAN_MB_CODE_RX_OVERRUN) {
/* This MB was overrun, we lost data */
offload->dev->stats.rx_over_errors++;
offload->dev->stats.rx_errors++;
}
} else {
reg_iflag1 = priv->read(&regs->iflag1);
if (!(reg_iflag1 & FLEXCAN_IFLAG_RX_FIFO_AVAILABLE))
return NULL;
reg_ctrl = priv->read(&mb->can_ctrl);
}
skb = alloc_can_skb(offload->dev, &cf);
if (!skb) {
skb = ERR_PTR(-ENOMEM);
goto mark_as_read;
}
/* increase timstamp to full 32 bit */
*timestamp = reg_ctrl << 16;
reg_id = priv->read(&mb->can_id);
if (reg_ctrl & FLEXCAN_MB_CNT_IDE)
cf->can_id = ((reg_id >> 0) & CAN_EFF_MASK) | CAN_EFF_FLAG;
else
cf->can_id = (reg_id >> 18) & CAN_SFF_MASK;
if (reg_ctrl & FLEXCAN_MB_CNT_RTR)
cf->can_id |= CAN_RTR_FLAG;
cf->can_dlc = get_can_dlc((reg_ctrl >> 16) & 0xf);
for (i = 0; i < cf->can_dlc; i += sizeof(u32)) {
__be32 data = cpu_to_be32(priv->read(&mb->data[i / sizeof(u32)]));
*(__be32 *)(cf->data + i) = data;
}
mark_as_read:
if (priv->devtype_data->quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP) {
/* Clear IRQ */
if (n < 32)
priv->write(BIT(n), &regs->iflag1);
else
priv->write(BIT(n - 32), &regs->iflag2);
} else {
priv->write(FLEXCAN_IFLAG_RX_FIFO_AVAILABLE, &regs->iflag1);
}
/* Read the Free Running Timer. It is optional but recommended
* to unlock Mailbox as soon as possible and make it available
* for reception.
*/
priv->read(&regs->timer);
return skb;
}
static inline u64 flexcan_read_reg_iflag_rx(struct flexcan_priv *priv)
{
struct flexcan_regs __iomem *regs = priv->regs;
u64 iflag;
iflag = (u64)priv->read(&regs->iflag2) << 32 |
priv->read(&regs->iflag1);
return iflag & priv->rx_mask;
}
static irqreturn_t flexcan_irq(int irq, void *dev_id)
{
struct net_device *dev = dev_id;
struct net_device_stats *stats = &dev->stats;
struct flexcan_priv *priv = netdev_priv(dev);
struct flexcan_regs __iomem *regs = priv->regs;
irqreturn_t handled = IRQ_NONE;
can: flexcan: Always use last mailbox for TX Essentially this patch moves the TX mailbox to position 63, regardless of timestamp based offloading or RX FIFO. So mainly the iflag register usage regarding TX has changed. The rest is consolidating RX FIFO and timestamp offloading as they now use both the same TX mailbox. The reason is a very annoying behavior regarding sending RTR frames when _not_ using RX FIFO: If a TX mailbox sent a RTR frame it becomes a RX mailbox. For that reason flexcan_irq disables the TX mailbox again. But if during the time the RTR was sent and the TX mailbox is disabled a new CAN frames is received, it is lost without notice. The reason is that so-called "Move-in" process starts from the lowest mailbox which happen to be a TX mailbox set to EMPTY. Steps to reproduce (I used an imx7d): 1. generate regular bursts of messages 2. send a RTR from flexcan with higher priority than burst messages every 1ms, e.g. cangen -I 0x100 -L 0 -g 1 -R can0 3. notice a lost message without notification after some seconds When running an iperf in parallel this problem is occurring even more frequently. Using filters is not possible as at least one single CAN-ID is allowed. Handling the TX MB during RX is also not possible as there is no race-free disable of RX MB. There is still a slight window when the described problem can occur. But for that all RX MB must be in use which is essentially next to an overrun. Still there will be no indication if it ever occurs. Signed-off-by: Alexander Stein <alexander.stein@systec-electronic.com> Cc: linux-stable <stable@vger.kernel.org> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2018-10-11 23:01:25 +08:00
u32 reg_iflag2, reg_esr;
can: flexcan: implement error passive state quirk Add FLEXCAN_QUIRK_BROKEN_PERR_STATE for better description of the missing error passive interrupt quirk. Error interrupt flooding may happen if the broken error state quirk fix is enabled. For example, in case there is singled out node on the bus and the node sends a frame, then error interrupt flooding happens and will not stop because the node cannot go to bus off. The flooding will stop after another node connected to the bus again. If high bitrate configured on the low end system, then the flooding may causes performance issue, hence, this patch mitigates this by: 1. disable error interrupt upon error passive state transition 2. re-enable error interrupt upon error warning state transition 3. disable/enable error interrupt upon error active state transition depends on FLEXCAN_QUIRK_BROKEN_WERR_STATE In this way, the driver is still able to report correct state transitions without additional latency. When there are bus problems, flooding of error interrupts is limited to the number of frames required to change state from error warning to error passive if the core has [TR]WRN_INT connected (FLEXCAN_QUIRK_BROKEN_WERR_STATE is not enabled), otherwise, the flooding is limited to the number of frames required to change state from error active to error passive. Signed-off-by: Zhu Yi <yi.zhu5@cn.bosch.com> Signed-off-by: Mark Jonas <mark.jonas@de.bosch.com> Acked-by: Wolfgang Grandegger <wg@grandegger.com> Cc: linux-stable <stable@vger.kernel.org> # >= v4.11 Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2017-09-15 15:03:58 +08:00
enum can_state last_state = priv->can.state;
/* reception interrupt */
if (priv->devtype_data->quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP) {
u64 reg_iflag_rx;
int ret;
while ((reg_iflag_rx = flexcan_read_reg_iflag_rx(priv))) {
handled = IRQ_HANDLED;
ret = can_rx_offload_irq_offload_timestamp(&priv->offload,
reg_iflag_rx);
if (!ret)
break;
}
} else {
can: flexcan: Always use last mailbox for TX Essentially this patch moves the TX mailbox to position 63, regardless of timestamp based offloading or RX FIFO. So mainly the iflag register usage regarding TX has changed. The rest is consolidating RX FIFO and timestamp offloading as they now use both the same TX mailbox. The reason is a very annoying behavior regarding sending RTR frames when _not_ using RX FIFO: If a TX mailbox sent a RTR frame it becomes a RX mailbox. For that reason flexcan_irq disables the TX mailbox again. But if during the time the RTR was sent and the TX mailbox is disabled a new CAN frames is received, it is lost without notice. The reason is that so-called "Move-in" process starts from the lowest mailbox which happen to be a TX mailbox set to EMPTY. Steps to reproduce (I used an imx7d): 1. generate regular bursts of messages 2. send a RTR from flexcan with higher priority than burst messages every 1ms, e.g. cangen -I 0x100 -L 0 -g 1 -R can0 3. notice a lost message without notification after some seconds When running an iperf in parallel this problem is occurring even more frequently. Using filters is not possible as at least one single CAN-ID is allowed. Handling the TX MB during RX is also not possible as there is no race-free disable of RX MB. There is still a slight window when the described problem can occur. But for that all RX MB must be in use which is essentially next to an overrun. Still there will be no indication if it ever occurs. Signed-off-by: Alexander Stein <alexander.stein@systec-electronic.com> Cc: linux-stable <stable@vger.kernel.org> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2018-10-11 23:01:25 +08:00
u32 reg_iflag1;
reg_iflag1 = priv->read(&regs->iflag1);
if (reg_iflag1 & FLEXCAN_IFLAG_RX_FIFO_AVAILABLE) {
handled = IRQ_HANDLED;
can_rx_offload_irq_offload_fifo(&priv->offload);
}
/* FIFO overflow interrupt */
if (reg_iflag1 & FLEXCAN_IFLAG_RX_FIFO_OVERFLOW) {
handled = IRQ_HANDLED;
priv->write(FLEXCAN_IFLAG_RX_FIFO_OVERFLOW,
&regs->iflag1);
dev->stats.rx_over_errors++;
dev->stats.rx_errors++;
}
}
can: flexcan: Always use last mailbox for TX Essentially this patch moves the TX mailbox to position 63, regardless of timestamp based offloading or RX FIFO. So mainly the iflag register usage regarding TX has changed. The rest is consolidating RX FIFO and timestamp offloading as they now use both the same TX mailbox. The reason is a very annoying behavior regarding sending RTR frames when _not_ using RX FIFO: If a TX mailbox sent a RTR frame it becomes a RX mailbox. For that reason flexcan_irq disables the TX mailbox again. But if during the time the RTR was sent and the TX mailbox is disabled a new CAN frames is received, it is lost without notice. The reason is that so-called "Move-in" process starts from the lowest mailbox which happen to be a TX mailbox set to EMPTY. Steps to reproduce (I used an imx7d): 1. generate regular bursts of messages 2. send a RTR from flexcan with higher priority than burst messages every 1ms, e.g. cangen -I 0x100 -L 0 -g 1 -R can0 3. notice a lost message without notification after some seconds When running an iperf in parallel this problem is occurring even more frequently. Using filters is not possible as at least one single CAN-ID is allowed. Handling the TX MB during RX is also not possible as there is no race-free disable of RX MB. There is still a slight window when the described problem can occur. But for that all RX MB must be in use which is essentially next to an overrun. Still there will be no indication if it ever occurs. Signed-off-by: Alexander Stein <alexander.stein@systec-electronic.com> Cc: linux-stable <stable@vger.kernel.org> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2018-10-11 23:01:25 +08:00
reg_iflag2 = priv->read(&regs->iflag2);
/* transmission complete interrupt */
if (reg_iflag2 & FLEXCAN_IFLAG2_MB(priv->tx_mb_idx)) {
u32 reg_ctrl = priv->read(&priv->tx_mb->can_ctrl);
handled = IRQ_HANDLED;
stats->tx_bytes += can_rx_offload_get_echo_skb(&priv->offload,
0, reg_ctrl << 16);
stats->tx_packets++;
can_led_event(dev, CAN_LED_EVENT_TX);
/* after sending a RTR frame MB is in RX mode */
priv->write(FLEXCAN_MB_CODE_TX_INACTIVE,
&priv->tx_mb->can_ctrl);
priv->write(FLEXCAN_IFLAG2_MB(priv->tx_mb_idx), &regs->iflag2);
netif_wake_queue(dev);
}
reg_esr = priv->read(&regs->esr);
/* ACK all bus error and state change IRQ sources */
if (reg_esr & FLEXCAN_ESR_ALL_INT) {
handled = IRQ_HANDLED;
priv->write(reg_esr & FLEXCAN_ESR_ALL_INT, &regs->esr);
}
/* state change interrupt or broken error state quirk fix is enabled */
if ((reg_esr & FLEXCAN_ESR_ERR_STATE) ||
can: flexcan: implement error passive state quirk Add FLEXCAN_QUIRK_BROKEN_PERR_STATE for better description of the missing error passive interrupt quirk. Error interrupt flooding may happen if the broken error state quirk fix is enabled. For example, in case there is singled out node on the bus and the node sends a frame, then error interrupt flooding happens and will not stop because the node cannot go to bus off. The flooding will stop after another node connected to the bus again. If high bitrate configured on the low end system, then the flooding may causes performance issue, hence, this patch mitigates this by: 1. disable error interrupt upon error passive state transition 2. re-enable error interrupt upon error warning state transition 3. disable/enable error interrupt upon error active state transition depends on FLEXCAN_QUIRK_BROKEN_WERR_STATE In this way, the driver is still able to report correct state transitions without additional latency. When there are bus problems, flooding of error interrupts is limited to the number of frames required to change state from error warning to error passive if the core has [TR]WRN_INT connected (FLEXCAN_QUIRK_BROKEN_WERR_STATE is not enabled), otherwise, the flooding is limited to the number of frames required to change state from error active to error passive. Signed-off-by: Zhu Yi <yi.zhu5@cn.bosch.com> Signed-off-by: Mark Jonas <mark.jonas@de.bosch.com> Acked-by: Wolfgang Grandegger <wg@grandegger.com> Cc: linux-stable <stable@vger.kernel.org> # >= v4.11 Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2017-09-15 15:03:58 +08:00
(priv->devtype_data->quirks & (FLEXCAN_QUIRK_BROKEN_WERR_STATE |
FLEXCAN_QUIRK_BROKEN_PERR_STATE)))
flexcan_irq_state(dev, reg_esr);
/* bus error IRQ - handle if bus error reporting is activated */
if ((reg_esr & FLEXCAN_ESR_ERR_BUS) &&
(priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING))
flexcan_irq_bus_err(dev, reg_esr);
can: flexcan: implement error passive state quirk Add FLEXCAN_QUIRK_BROKEN_PERR_STATE for better description of the missing error passive interrupt quirk. Error interrupt flooding may happen if the broken error state quirk fix is enabled. For example, in case there is singled out node on the bus and the node sends a frame, then error interrupt flooding happens and will not stop because the node cannot go to bus off. The flooding will stop after another node connected to the bus again. If high bitrate configured on the low end system, then the flooding may causes performance issue, hence, this patch mitigates this by: 1. disable error interrupt upon error passive state transition 2. re-enable error interrupt upon error warning state transition 3. disable/enable error interrupt upon error active state transition depends on FLEXCAN_QUIRK_BROKEN_WERR_STATE In this way, the driver is still able to report correct state transitions without additional latency. When there are bus problems, flooding of error interrupts is limited to the number of frames required to change state from error warning to error passive if the core has [TR]WRN_INT connected (FLEXCAN_QUIRK_BROKEN_WERR_STATE is not enabled), otherwise, the flooding is limited to the number of frames required to change state from error active to error passive. Signed-off-by: Zhu Yi <yi.zhu5@cn.bosch.com> Signed-off-by: Mark Jonas <mark.jonas@de.bosch.com> Acked-by: Wolfgang Grandegger <wg@grandegger.com> Cc: linux-stable <stable@vger.kernel.org> # >= v4.11 Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2017-09-15 15:03:58 +08:00
/* availability of error interrupt among state transitions in case
* bus error reporting is de-activated and
* FLEXCAN_QUIRK_BROKEN_PERR_STATE is enabled:
* +--------------------------------------------------------------+
* | +----------------------------------------------+ [stopped / |
* | | | sleeping] -+
* +-+-> active <-> warning <-> passive -> bus off -+
* ___________^^^^^^^^^^^^_______________________________
* disabled(1) enabled disabled
*
* (1): enabled if FLEXCAN_QUIRK_BROKEN_WERR_STATE is enabled
*/
if ((last_state != priv->can.state) &&
(priv->devtype_data->quirks & FLEXCAN_QUIRK_BROKEN_PERR_STATE) &&
!(priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING)) {
switch (priv->can.state) {
case CAN_STATE_ERROR_ACTIVE:
if (priv->devtype_data->quirks &
FLEXCAN_QUIRK_BROKEN_WERR_STATE)
flexcan_error_irq_enable(priv);
else
flexcan_error_irq_disable(priv);
break;
case CAN_STATE_ERROR_WARNING:
flexcan_error_irq_enable(priv);
break;
case CAN_STATE_ERROR_PASSIVE:
case CAN_STATE_BUS_OFF:
flexcan_error_irq_disable(priv);
break;
default:
break;
}
}
return handled;
}
static void flexcan_set_bittiming(struct net_device *dev)
{
const struct flexcan_priv *priv = netdev_priv(dev);
const struct can_bittiming *bt = &priv->can.bittiming;
struct flexcan_regs __iomem *regs = priv->regs;
u32 reg;
reg = priv->read(&regs->ctrl);
reg &= ~(FLEXCAN_CTRL_PRESDIV(0xff) |
FLEXCAN_CTRL_RJW(0x3) |
FLEXCAN_CTRL_PSEG1(0x7) |
FLEXCAN_CTRL_PSEG2(0x7) |
FLEXCAN_CTRL_PROPSEG(0x7) |
FLEXCAN_CTRL_LPB |
FLEXCAN_CTRL_SMP |
FLEXCAN_CTRL_LOM);
reg |= FLEXCAN_CTRL_PRESDIV(bt->brp - 1) |
FLEXCAN_CTRL_PSEG1(bt->phase_seg1 - 1) |
FLEXCAN_CTRL_PSEG2(bt->phase_seg2 - 1) |
FLEXCAN_CTRL_RJW(bt->sjw - 1) |
FLEXCAN_CTRL_PROPSEG(bt->prop_seg - 1);
if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK)
reg |= FLEXCAN_CTRL_LPB;
if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
reg |= FLEXCAN_CTRL_LOM;
if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
reg |= FLEXCAN_CTRL_SMP;
netdev_dbg(dev, "writing ctrl=0x%08x\n", reg);
priv->write(reg, &regs->ctrl);
/* print chip status */
netdev_dbg(dev, "%s: mcr=0x%08x ctrl=0x%08x\n", __func__,
priv->read(&regs->mcr), priv->read(&regs->ctrl));
}
/* flexcan_chip_start
*
* this functions is entered with clocks enabled
*
*/
static int flexcan_chip_start(struct net_device *dev)
{
struct flexcan_priv *priv = netdev_priv(dev);
struct flexcan_regs __iomem *regs = priv->regs;
u32 reg_mcr, reg_ctrl, reg_ctrl2, reg_mecr;
u64 reg_imask;
int err, i;
struct flexcan_mb __iomem *mb;
/* enable module */
err = flexcan_chip_enable(priv);
if (err)
return err;
/* soft reset */
err = flexcan_chip_softreset(priv);
if (err)
goto out_chip_disable;
flexcan_set_bittiming(dev);
/* MCR
*
* enable freeze
* halt now
* only supervisor access
* enable warning int
* enable individual RX masking
* choose format C
* set max mailbox number
*/
reg_mcr = priv->read(&regs->mcr);
reg_mcr &= ~FLEXCAN_MCR_MAXMB(0xff);
reg_mcr |= FLEXCAN_MCR_FRZ | FLEXCAN_MCR_HALT | FLEXCAN_MCR_SUPV |
FLEXCAN_MCR_WRN_EN | FLEXCAN_MCR_IRMQ | FLEXCAN_MCR_IDAM_C |
FLEXCAN_MCR_MAXMB(priv->tx_mb_idx);
/* MCR
*
* FIFO:
* - disable for timestamp mode
* - enable for FIFO mode
*/
can: flexcan: Always use last mailbox for TX Essentially this patch moves the TX mailbox to position 63, regardless of timestamp based offloading or RX FIFO. So mainly the iflag register usage regarding TX has changed. The rest is consolidating RX FIFO and timestamp offloading as they now use both the same TX mailbox. The reason is a very annoying behavior regarding sending RTR frames when _not_ using RX FIFO: If a TX mailbox sent a RTR frame it becomes a RX mailbox. For that reason flexcan_irq disables the TX mailbox again. But if during the time the RTR was sent and the TX mailbox is disabled a new CAN frames is received, it is lost without notice. The reason is that so-called "Move-in" process starts from the lowest mailbox which happen to be a TX mailbox set to EMPTY. Steps to reproduce (I used an imx7d): 1. generate regular bursts of messages 2. send a RTR from flexcan with higher priority than burst messages every 1ms, e.g. cangen -I 0x100 -L 0 -g 1 -R can0 3. notice a lost message without notification after some seconds When running an iperf in parallel this problem is occurring even more frequently. Using filters is not possible as at least one single CAN-ID is allowed. Handling the TX MB during RX is also not possible as there is no race-free disable of RX MB. There is still a slight window when the described problem can occur. But for that all RX MB must be in use which is essentially next to an overrun. Still there will be no indication if it ever occurs. Signed-off-by: Alexander Stein <alexander.stein@systec-electronic.com> Cc: linux-stable <stable@vger.kernel.org> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2018-10-11 23:01:25 +08:00
if (priv->devtype_data->quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP)
reg_mcr &= ~FLEXCAN_MCR_FEN;
can: flexcan: Always use last mailbox for TX Essentially this patch moves the TX mailbox to position 63, regardless of timestamp based offloading or RX FIFO. So mainly the iflag register usage regarding TX has changed. The rest is consolidating RX FIFO and timestamp offloading as they now use both the same TX mailbox. The reason is a very annoying behavior regarding sending RTR frames when _not_ using RX FIFO: If a TX mailbox sent a RTR frame it becomes a RX mailbox. For that reason flexcan_irq disables the TX mailbox again. But if during the time the RTR was sent and the TX mailbox is disabled a new CAN frames is received, it is lost without notice. The reason is that so-called "Move-in" process starts from the lowest mailbox which happen to be a TX mailbox set to EMPTY. Steps to reproduce (I used an imx7d): 1. generate regular bursts of messages 2. send a RTR from flexcan with higher priority than burst messages every 1ms, e.g. cangen -I 0x100 -L 0 -g 1 -R can0 3. notice a lost message without notification after some seconds When running an iperf in parallel this problem is occurring even more frequently. Using filters is not possible as at least one single CAN-ID is allowed. Handling the TX MB during RX is also not possible as there is no race-free disable of RX MB. There is still a slight window when the described problem can occur. But for that all RX MB must be in use which is essentially next to an overrun. Still there will be no indication if it ever occurs. Signed-off-by: Alexander Stein <alexander.stein@systec-electronic.com> Cc: linux-stable <stable@vger.kernel.org> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2018-10-11 23:01:25 +08:00
else
reg_mcr |= FLEXCAN_MCR_FEN;
/* MCR
*
* NOTE: In loopback mode, the CAN_MCR[SRXDIS] cannot be
* asserted because this will impede the self reception
* of a transmitted message. This is not documented in
* earlier versions of flexcan block guide.
*
* Self Reception:
* - enable Self Reception for loopback mode
* (by clearing "Self Reception Disable" bit)
* - disable for normal operation
*/
if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK)
reg_mcr &= ~FLEXCAN_MCR_SRX_DIS;
else
reg_mcr |= FLEXCAN_MCR_SRX_DIS;
netdev_dbg(dev, "%s: writing mcr=0x%08x", __func__, reg_mcr);
priv->write(reg_mcr, &regs->mcr);
/* CTRL
*
* disable timer sync feature
*
* disable auto busoff recovery
* transmit lowest buffer first
*
* enable tx and rx warning interrupt
* enable bus off interrupt
* (== FLEXCAN_CTRL_ERR_STATE)
*/
reg_ctrl = priv->read(&regs->ctrl);
reg_ctrl &= ~FLEXCAN_CTRL_TSYN;
reg_ctrl |= FLEXCAN_CTRL_BOFF_REC | FLEXCAN_CTRL_LBUF |
FLEXCAN_CTRL_ERR_STATE;
/* enable the "error interrupt" (FLEXCAN_CTRL_ERR_MSK),
* on most Flexcan cores, too. Otherwise we don't get
* any error warning or passive interrupts.
*/
if (priv->devtype_data->quirks & FLEXCAN_QUIRK_BROKEN_WERR_STATE ||
priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING)
reg_ctrl |= FLEXCAN_CTRL_ERR_MSK;
else
reg_ctrl &= ~FLEXCAN_CTRL_ERR_MSK;
/* save for later use */
priv->reg_ctrl_default = reg_ctrl;
/* leave interrupts disabled for now */
reg_ctrl &= ~FLEXCAN_CTRL_ERR_ALL;
netdev_dbg(dev, "%s: writing ctrl=0x%08x", __func__, reg_ctrl);
priv->write(reg_ctrl, &regs->ctrl);
if ((priv->devtype_data->quirks & FLEXCAN_QUIRK_ENABLE_EACEN_RRS)) {
reg_ctrl2 = priv->read(&regs->ctrl2);
reg_ctrl2 |= FLEXCAN_CTRL2_EACEN | FLEXCAN_CTRL2_RRS;
priv->write(reg_ctrl2, &regs->ctrl2);
}
if (priv->devtype_data->quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP) {
can: flexcan: Always use last mailbox for TX Essentially this patch moves the TX mailbox to position 63, regardless of timestamp based offloading or RX FIFO. So mainly the iflag register usage regarding TX has changed. The rest is consolidating RX FIFO and timestamp offloading as they now use both the same TX mailbox. The reason is a very annoying behavior regarding sending RTR frames when _not_ using RX FIFO: If a TX mailbox sent a RTR frame it becomes a RX mailbox. For that reason flexcan_irq disables the TX mailbox again. But if during the time the RTR was sent and the TX mailbox is disabled a new CAN frames is received, it is lost without notice. The reason is that so-called "Move-in" process starts from the lowest mailbox which happen to be a TX mailbox set to EMPTY. Steps to reproduce (I used an imx7d): 1. generate regular bursts of messages 2. send a RTR from flexcan with higher priority than burst messages every 1ms, e.g. cangen -I 0x100 -L 0 -g 1 -R can0 3. notice a lost message without notification after some seconds When running an iperf in parallel this problem is occurring even more frequently. Using filters is not possible as at least one single CAN-ID is allowed. Handling the TX MB during RX is also not possible as there is no race-free disable of RX MB. There is still a slight window when the described problem can occur. But for that all RX MB must be in use which is essentially next to an overrun. Still there will be no indication if it ever occurs. Signed-off-by: Alexander Stein <alexander.stein@systec-electronic.com> Cc: linux-stable <stable@vger.kernel.org> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2018-10-11 23:01:25 +08:00
for (i = priv->offload.mb_first; i <= priv->offload.mb_last; i++) {
mb = flexcan_get_mb(priv, i);
priv->write(FLEXCAN_MB_CODE_RX_EMPTY,
&mb->can_ctrl);
can: flexcan: Always use last mailbox for TX Essentially this patch moves the TX mailbox to position 63, regardless of timestamp based offloading or RX FIFO. So mainly the iflag register usage regarding TX has changed. The rest is consolidating RX FIFO and timestamp offloading as they now use both the same TX mailbox. The reason is a very annoying behavior regarding sending RTR frames when _not_ using RX FIFO: If a TX mailbox sent a RTR frame it becomes a RX mailbox. For that reason flexcan_irq disables the TX mailbox again. But if during the time the RTR was sent and the TX mailbox is disabled a new CAN frames is received, it is lost without notice. The reason is that so-called "Move-in" process starts from the lowest mailbox which happen to be a TX mailbox set to EMPTY. Steps to reproduce (I used an imx7d): 1. generate regular bursts of messages 2. send a RTR from flexcan with higher priority than burst messages every 1ms, e.g. cangen -I 0x100 -L 0 -g 1 -R can0 3. notice a lost message without notification after some seconds When running an iperf in parallel this problem is occurring even more frequently. Using filters is not possible as at least one single CAN-ID is allowed. Handling the TX MB during RX is also not possible as there is no race-free disable of RX MB. There is still a slight window when the described problem can occur. But for that all RX MB must be in use which is essentially next to an overrun. Still there will be no indication if it ever occurs. Signed-off-by: Alexander Stein <alexander.stein@systec-electronic.com> Cc: linux-stable <stable@vger.kernel.org> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2018-10-11 23:01:25 +08:00
}
} else {
/* clear and invalidate unused mailboxes first */
for (i = FLEXCAN_TX_MB_RESERVED_OFF_FIFO; i < priv->mb_count; i++) {
mb = flexcan_get_mb(priv, i);
can: flexcan: Always use last mailbox for TX Essentially this patch moves the TX mailbox to position 63, regardless of timestamp based offloading or RX FIFO. So mainly the iflag register usage regarding TX has changed. The rest is consolidating RX FIFO and timestamp offloading as they now use both the same TX mailbox. The reason is a very annoying behavior regarding sending RTR frames when _not_ using RX FIFO: If a TX mailbox sent a RTR frame it becomes a RX mailbox. For that reason flexcan_irq disables the TX mailbox again. But if during the time the RTR was sent and the TX mailbox is disabled a new CAN frames is received, it is lost without notice. The reason is that so-called "Move-in" process starts from the lowest mailbox which happen to be a TX mailbox set to EMPTY. Steps to reproduce (I used an imx7d): 1. generate regular bursts of messages 2. send a RTR from flexcan with higher priority than burst messages every 1ms, e.g. cangen -I 0x100 -L 0 -g 1 -R can0 3. notice a lost message without notification after some seconds When running an iperf in parallel this problem is occurring even more frequently. Using filters is not possible as at least one single CAN-ID is allowed. Handling the TX MB during RX is also not possible as there is no race-free disable of RX MB. There is still a slight window when the described problem can occur. But for that all RX MB must be in use which is essentially next to an overrun. Still there will be no indication if it ever occurs. Signed-off-by: Alexander Stein <alexander.stein@systec-electronic.com> Cc: linux-stable <stable@vger.kernel.org> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2018-10-11 23:01:25 +08:00
priv->write(FLEXCAN_MB_CODE_RX_INACTIVE,
&mb->can_ctrl);
can: flexcan: Always use last mailbox for TX Essentially this patch moves the TX mailbox to position 63, regardless of timestamp based offloading or RX FIFO. So mainly the iflag register usage regarding TX has changed. The rest is consolidating RX FIFO and timestamp offloading as they now use both the same TX mailbox. The reason is a very annoying behavior regarding sending RTR frames when _not_ using RX FIFO: If a TX mailbox sent a RTR frame it becomes a RX mailbox. For that reason flexcan_irq disables the TX mailbox again. But if during the time the RTR was sent and the TX mailbox is disabled a new CAN frames is received, it is lost without notice. The reason is that so-called "Move-in" process starts from the lowest mailbox which happen to be a TX mailbox set to EMPTY. Steps to reproduce (I used an imx7d): 1. generate regular bursts of messages 2. send a RTR from flexcan with higher priority than burst messages every 1ms, e.g. cangen -I 0x100 -L 0 -g 1 -R can0 3. notice a lost message without notification after some seconds When running an iperf in parallel this problem is occurring even more frequently. Using filters is not possible as at least one single CAN-ID is allowed. Handling the TX MB during RX is also not possible as there is no race-free disable of RX MB. There is still a slight window when the described problem can occur. But for that all RX MB must be in use which is essentially next to an overrun. Still there will be no indication if it ever occurs. Signed-off-by: Alexander Stein <alexander.stein@systec-electronic.com> Cc: linux-stable <stable@vger.kernel.org> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2018-10-11 23:01:25 +08:00
}
}
/* Errata ERR005829: mark first TX mailbox as INACTIVE */
priv->write(FLEXCAN_MB_CODE_TX_INACTIVE,
&priv->tx_mb_reserved->can_ctrl);
/* mark TX mailbox as INACTIVE */
priv->write(FLEXCAN_MB_CODE_TX_INACTIVE,
&priv->tx_mb->can_ctrl);
/* acceptance mask/acceptance code (accept everything) */
priv->write(0x0, &regs->rxgmask);
priv->write(0x0, &regs->rx14mask);
priv->write(0x0, &regs->rx15mask);
if (priv->devtype_data->quirks & FLEXCAN_QUIRK_DISABLE_RXFG)
priv->write(0x0, &regs->rxfgmask);
/* clear acceptance filters */
for (i = 0; i < priv->mb_count; i++)
priv->write(0, &regs->rximr[i]);
/* On Vybrid, disable memory error detection interrupts
* and freeze mode.
* This also works around errata e5295 which generates
* false positive memory errors and put the device in
* freeze mode.
*/
if (priv->devtype_data->quirks & FLEXCAN_QUIRK_DISABLE_MECR) {
/* Follow the protocol as described in "Detection
* and Correction of Memory Errors" to write to
* MECR register
*/
reg_ctrl2 = priv->read(&regs->ctrl2);
reg_ctrl2 |= FLEXCAN_CTRL2_ECRWRE;
priv->write(reg_ctrl2, &regs->ctrl2);
reg_mecr = priv->read(&regs->mecr);
reg_mecr &= ~FLEXCAN_MECR_ECRWRDIS;
priv->write(reg_mecr, &regs->mecr);
reg_mecr |= FLEXCAN_MECR_ECCDIS;
reg_mecr &= ~(FLEXCAN_MECR_NCEFAFRZ | FLEXCAN_MECR_HANCEI_MSK |
FLEXCAN_MECR_FANCEI_MSK);
priv->write(reg_mecr, &regs->mecr);
}
err = flexcan_transceiver_enable(priv);
if (err)
goto out_chip_disable;
/* synchronize with the can bus */
err = flexcan_chip_unfreeze(priv);
if (err)
goto out_transceiver_disable;
priv->can.state = CAN_STATE_ERROR_ACTIVE;
/* enable interrupts atomically */
disable_irq(dev->irq);
priv->write(priv->reg_ctrl_default, &regs->ctrl);
reg_imask = priv->rx_mask | FLEXCAN_IFLAG_MB(priv->tx_mb_idx);
priv->write(upper_32_bits(reg_imask), &regs->imask2);
priv->write(lower_32_bits(reg_imask), &regs->imask1);
enable_irq(dev->irq);
/* print chip status */
netdev_dbg(dev, "%s: reading mcr=0x%08x ctrl=0x%08x\n", __func__,
priv->read(&regs->mcr), priv->read(&regs->ctrl));
return 0;
out_transceiver_disable:
flexcan_transceiver_disable(priv);
out_chip_disable:
flexcan_chip_disable(priv);
return err;
}
/* flexcan_chip_stop
*
* this functions is entered with clocks enabled
*/
static void flexcan_chip_stop(struct net_device *dev)
{
struct flexcan_priv *priv = netdev_priv(dev);
struct flexcan_regs __iomem *regs = priv->regs;
/* freeze + disable module */
flexcan_chip_freeze(priv);
flexcan_chip_disable(priv);
/* Disable all interrupts */
priv->write(0, &regs->imask2);
priv->write(0, &regs->imask1);
priv->write(priv->reg_ctrl_default & ~FLEXCAN_CTRL_ERR_ALL,
&regs->ctrl);
flexcan_transceiver_disable(priv);
priv->can.state = CAN_STATE_STOPPED;
}
static int flexcan_open(struct net_device *dev)
{
struct flexcan_priv *priv = netdev_priv(dev);
int err;
err = pm_runtime_get_sync(priv->dev);
if (err < 0)
return err;
err = open_candev(dev);
if (err)
goto out_runtime_put;
err = request_irq(dev->irq, flexcan_irq, IRQF_SHARED, dev->name, dev);
if (err)
goto out_close;
priv->mb_size = sizeof(struct flexcan_mb) + CAN_MAX_DLEN;
priv->mb_count = (sizeof(priv->regs->mb[0]) / priv->mb_size) +
(sizeof(priv->regs->mb[1]) / priv->mb_size);
if (priv->devtype_data->quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP)
priv->tx_mb_reserved =
flexcan_get_mb(priv, FLEXCAN_TX_MB_RESERVED_OFF_TIMESTAMP);
else
priv->tx_mb_reserved =
flexcan_get_mb(priv, FLEXCAN_TX_MB_RESERVED_OFF_FIFO);
priv->tx_mb_idx = priv->mb_count - 1;
priv->tx_mb = flexcan_get_mb(priv, priv->tx_mb_idx);
priv->offload.mailbox_read = flexcan_mailbox_read;
if (priv->devtype_data->quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP) {
priv->offload.mb_first = FLEXCAN_RX_MB_OFF_TIMESTAMP_FIRST;
priv->offload.mb_last = priv->mb_count - 2;
priv->rx_mask = GENMASK_ULL(priv->offload.mb_last,
priv->offload.mb_first);
err = can_rx_offload_add_timestamp(dev, &priv->offload);
} else {
priv->rx_mask = FLEXCAN_IFLAG_RX_FIFO_OVERFLOW |
FLEXCAN_IFLAG_RX_FIFO_AVAILABLE;
err = can_rx_offload_add_fifo(dev, &priv->offload,
FLEXCAN_NAPI_WEIGHT);
}
if (err)
goto out_free_irq;
/* start chip and queuing */
err = flexcan_chip_start(dev);
if (err)
goto out_offload_del;
can_led_event(dev, CAN_LED_EVENT_OPEN);
can_rx_offload_enable(&priv->offload);
netif_start_queue(dev);
return 0;
out_offload_del:
can_rx_offload_del(&priv->offload);
out_free_irq:
free_irq(dev->irq, dev);
out_close:
close_candev(dev);
out_runtime_put:
pm_runtime_put(priv->dev);
return err;
}
static int flexcan_close(struct net_device *dev)
{
struct flexcan_priv *priv = netdev_priv(dev);
netif_stop_queue(dev);
can_rx_offload_disable(&priv->offload);
flexcan_chip_stop(dev);
can_rx_offload_del(&priv->offload);
free_irq(dev->irq, dev);
close_candev(dev);
pm_runtime_put(priv->dev);
can_led_event(dev, CAN_LED_EVENT_STOP);
return 0;
}
static int flexcan_set_mode(struct net_device *dev, enum can_mode mode)
{
int err;
switch (mode) {
case CAN_MODE_START:
err = flexcan_chip_start(dev);
if (err)
return err;
netif_wake_queue(dev);
break;
default:
return -EOPNOTSUPP;
}
return 0;
}
static const struct net_device_ops flexcan_netdev_ops = {
.ndo_open = flexcan_open,
.ndo_stop = flexcan_close,
.ndo_start_xmit = flexcan_start_xmit,
.ndo_change_mtu = can_change_mtu,
};
static int register_flexcandev(struct net_device *dev)
{
struct flexcan_priv *priv = netdev_priv(dev);
struct flexcan_regs __iomem *regs = priv->regs;
u32 reg, err;
err = flexcan_clks_enable(priv);
if (err)
return err;
/* select "bus clock", chip must be disabled */
err = flexcan_chip_disable(priv);
if (err)
goto out_clks_disable;
reg = priv->read(&regs->ctrl);
if (priv->clk_src)
reg |= FLEXCAN_CTRL_CLK_SRC;
else
reg &= ~FLEXCAN_CTRL_CLK_SRC;
priv->write(reg, &regs->ctrl);
err = flexcan_chip_enable(priv);
if (err)
goto out_chip_disable;
/* set freeze, halt and activate FIFO, restrict register access */
reg = priv->read(&regs->mcr);
reg |= FLEXCAN_MCR_FRZ | FLEXCAN_MCR_HALT |
FLEXCAN_MCR_FEN | FLEXCAN_MCR_SUPV;
priv->write(reg, &regs->mcr);
/* Currently we only support newer versions of this core
* featuring a RX hardware FIFO (although this driver doesn't
* make use of it on some cores). Older cores, found on some
* Coldfire derivates are not tested.
*/
reg = priv->read(&regs->mcr);
if (!(reg & FLEXCAN_MCR_FEN)) {
netdev_err(dev, "Could not enable RX FIFO, unsupported core\n");
err = -ENODEV;
goto out_chip_disable;
}
err = register_candev(dev);
if (err)
goto out_chip_disable;
/* Disable core and let pm_runtime_put() disable the clocks.
* If CONFIG_PM is not enabled, the clocks will stay powered.
*/
flexcan_chip_disable(priv);
pm_runtime_put(priv->dev);
return 0;
out_chip_disable:
flexcan_chip_disable(priv);
out_clks_disable:
flexcan_clks_disable(priv);
return err;
}
static void unregister_flexcandev(struct net_device *dev)
{
unregister_candev(dev);
}
static int flexcan_setup_stop_mode(struct platform_device *pdev)
{
struct net_device *dev = platform_get_drvdata(pdev);
struct device_node *np = pdev->dev.of_node;
struct device_node *gpr_np;
struct flexcan_priv *priv;
phandle phandle;
u32 out_val[5];
int ret;
if (!np)
return -EINVAL;
/* stop mode property format is:
* <&gpr req_gpr req_bit ack_gpr ack_bit>.
*/
ret = of_property_read_u32_array(np, "fsl,stop-mode", out_val,
ARRAY_SIZE(out_val));
if (ret) {
dev_dbg(&pdev->dev, "no stop-mode property\n");
return ret;
}
phandle = *out_val;
gpr_np = of_find_node_by_phandle(phandle);
if (!gpr_np) {
dev_dbg(&pdev->dev, "could not find gpr node by phandle\n");
return -ENODEV;
}
priv = netdev_priv(dev);
priv->stm.gpr = syscon_node_to_regmap(gpr_np);
if (IS_ERR(priv->stm.gpr)) {
dev_dbg(&pdev->dev, "could not find gpr regmap\n");
ret = PTR_ERR(priv->stm.gpr);
goto out_put_node;
}
priv->stm.req_gpr = out_val[1];
priv->stm.req_bit = out_val[2];
priv->stm.ack_gpr = out_val[3];
priv->stm.ack_bit = out_val[4];
dev_dbg(&pdev->dev,
"gpr %s req_gpr=0x02%x req_bit=%u ack_gpr=0x02%x ack_bit=%u\n",
gpr_np->full_name, priv->stm.req_gpr, priv->stm.req_bit,
priv->stm.ack_gpr, priv->stm.ack_bit);
device_set_wakeup_capable(&pdev->dev, true);
if (of_property_read_bool(np, "wakeup-source"))
device_set_wakeup_enable(&pdev->dev, true);
return 0;
out_put_node:
of_node_put(gpr_np);
return ret;
}
static const struct of_device_id flexcan_of_match[] = {
{ .compatible = "fsl,imx6q-flexcan", .data = &fsl_imx6q_devtype_data, },
{ .compatible = "fsl,imx28-flexcan", .data = &fsl_imx28_devtype_data, },
{ .compatible = "fsl,imx53-flexcan", .data = &fsl_imx25_devtype_data, },
{ .compatible = "fsl,imx35-flexcan", .data = &fsl_imx25_devtype_data, },
{ .compatible = "fsl,imx25-flexcan", .data = &fsl_imx25_devtype_data, },
{ .compatible = "fsl,p1010-flexcan", .data = &fsl_p1010_devtype_data, },
{ .compatible = "fsl,vf610-flexcan", .data = &fsl_vf610_devtype_data, },
{ .compatible = "fsl,ls1021ar2-flexcan", .data = &fsl_ls1021a_r2_devtype_data, },
{ /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, flexcan_of_match);
static const struct platform_device_id flexcan_id_table[] = {
{ .name = "flexcan", .driver_data = (kernel_ulong_t)&fsl_p1010_devtype_data, },
{ /* sentinel */ },
};
MODULE_DEVICE_TABLE(platform, flexcan_id_table);
static int flexcan_probe(struct platform_device *pdev)
{
const struct of_device_id *of_id;
const struct flexcan_devtype_data *devtype_data;
struct net_device *dev;
struct flexcan_priv *priv;
struct regulator *reg_xceiver;
struct clk *clk_ipg = NULL, *clk_per = NULL;
struct flexcan_regs __iomem *regs;
int err, irq;
u8 clk_src = 1;
u32 clock_freq = 0;
reg_xceiver = devm_regulator_get(&pdev->dev, "xceiver");
if (PTR_ERR(reg_xceiver) == -EPROBE_DEFER)
return -EPROBE_DEFER;
else if (IS_ERR(reg_xceiver))
reg_xceiver = NULL;
if (pdev->dev.of_node) {
of_property_read_u32(pdev->dev.of_node,
"clock-frequency", &clock_freq);
of_property_read_u8(pdev->dev.of_node,
"fsl,clk-source", &clk_src);
}
if (!clock_freq) {
clk_ipg = devm_clk_get(&pdev->dev, "ipg");
if (IS_ERR(clk_ipg)) {
dev_err(&pdev->dev, "no ipg clock defined\n");
return PTR_ERR(clk_ipg);
}
clk_per = devm_clk_get(&pdev->dev, "per");
if (IS_ERR(clk_per)) {
dev_err(&pdev->dev, "no per clock defined\n");
return PTR_ERR(clk_per);
}
clock_freq = clk_get_rate(clk_per);
}
irq = platform_get_irq(pdev, 0);
if (irq <= 0)
return -ENODEV;
regs = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(regs))
return PTR_ERR(regs);
of_id = of_match_device(flexcan_of_match, &pdev->dev);
if (of_id) {
devtype_data = of_id->data;
} else if (platform_get_device_id(pdev)->driver_data) {
devtype_data = (struct flexcan_devtype_data *)
platform_get_device_id(pdev)->driver_data;
} else {
return -ENODEV;
}
dev = alloc_candev(sizeof(struct flexcan_priv), 1);
if (!dev)
return -ENOMEM;
platform_set_drvdata(pdev, dev);
SET_NETDEV_DEV(dev, &pdev->dev);
dev->netdev_ops = &flexcan_netdev_ops;
dev->irq = irq;
dev->flags |= IFF_ECHO;
priv = netdev_priv(dev);
if (of_property_read_bool(pdev->dev.of_node, "big-endian") ||
devtype_data->quirks & FLEXCAN_QUIRK_DEFAULT_BIG_ENDIAN) {
priv->read = flexcan_read_be;
priv->write = flexcan_write_be;
} else {
priv->read = flexcan_read_le;
priv->write = flexcan_write_le;
}
priv->dev = &pdev->dev;
priv->can.clock.freq = clock_freq;
priv->can.bittiming_const = &flexcan_bittiming_const;
priv->can.do_set_mode = flexcan_set_mode;
priv->can.do_get_berr_counter = flexcan_get_berr_counter;
priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
CAN_CTRLMODE_LISTENONLY | CAN_CTRLMODE_3_SAMPLES |
CAN_CTRLMODE_BERR_REPORTING;
priv->regs = regs;
priv->clk_ipg = clk_ipg;
priv->clk_per = clk_per;
priv->clk_src = clk_src;
priv->devtype_data = devtype_data;
priv->reg_xceiver = reg_xceiver;
pm_runtime_get_noresume(&pdev->dev);
pm_runtime_set_active(&pdev->dev);
pm_runtime_enable(&pdev->dev);
err = register_flexcandev(dev);
if (err) {
dev_err(&pdev->dev, "registering netdev failed\n");
goto failed_register;
}
devm_can_led_init(dev);
if (priv->devtype_data->quirks & FLEXCAN_QUIRK_SETUP_STOP_MODE) {
err = flexcan_setup_stop_mode(pdev);
if (err)
dev_dbg(&pdev->dev, "failed to setup stop-mode\n");
}
return 0;
failed_register:
free_candev(dev);
return err;
}
static int flexcan_remove(struct platform_device *pdev)
{
struct net_device *dev = platform_get_drvdata(pdev);
unregister_flexcandev(dev);
pm_runtime_disable(&pdev->dev);
free_candev(dev);
return 0;
}
static int __maybe_unused flexcan_suspend(struct device *device)
{
struct net_device *dev = dev_get_drvdata(device);
struct flexcan_priv *priv = netdev_priv(dev);
int err = 0;
if (netif_running(dev)) {
/* if wakeup is enabled, enter stop mode
* else enter disabled mode.
*/
if (device_may_wakeup(device)) {
enable_irq_wake(dev->irq);
err = flexcan_enter_stop_mode(priv);
if (err)
return err;
} else {
err = flexcan_chip_disable(priv);
if (err)
return err;
err = pm_runtime_force_suspend(device);
}
netif_stop_queue(dev);
netif_device_detach(dev);
}
priv->can.state = CAN_STATE_SLEEPING;
return err;
}
static int __maybe_unused flexcan_resume(struct device *device)
{
struct net_device *dev = dev_get_drvdata(device);
struct flexcan_priv *priv = netdev_priv(dev);
int err = 0;
priv->can.state = CAN_STATE_ERROR_ACTIVE;
if (netif_running(dev)) {
netif_device_attach(dev);
netif_start_queue(dev);
if (device_may_wakeup(device)) {
disable_irq_wake(dev->irq);
} else {
err = pm_runtime_force_resume(device);
if (err)
return err;
err = flexcan_chip_enable(priv);
}
}
return err;
}
static int __maybe_unused flexcan_runtime_suspend(struct device *device)
{
struct net_device *dev = dev_get_drvdata(device);
struct flexcan_priv *priv = netdev_priv(dev);
flexcan_clks_disable(priv);
return 0;
}
static int __maybe_unused flexcan_runtime_resume(struct device *device)
{
struct net_device *dev = dev_get_drvdata(device);
struct flexcan_priv *priv = netdev_priv(dev);
return flexcan_clks_enable(priv);
}
static int __maybe_unused flexcan_noirq_suspend(struct device *device)
{
struct net_device *dev = dev_get_drvdata(device);
struct flexcan_priv *priv = netdev_priv(dev);
if (netif_running(dev) && device_may_wakeup(device))
flexcan_enable_wakeup_irq(priv, true);
return 0;
}
static int __maybe_unused flexcan_noirq_resume(struct device *device)
{
struct net_device *dev = dev_get_drvdata(device);
struct flexcan_priv *priv = netdev_priv(dev);
int err;
if (netif_running(dev) && device_may_wakeup(device)) {
flexcan_enable_wakeup_irq(priv, false);
err = flexcan_exit_stop_mode(priv);
if (err)
return err;
}
return 0;
}
static const struct dev_pm_ops flexcan_pm_ops = {
SET_SYSTEM_SLEEP_PM_OPS(flexcan_suspend, flexcan_resume)
SET_RUNTIME_PM_OPS(flexcan_runtime_suspend, flexcan_runtime_resume, NULL)
SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(flexcan_noirq_suspend, flexcan_noirq_resume)
};
static struct platform_driver flexcan_driver = {
.driver = {
.name = DRV_NAME,
.pm = &flexcan_pm_ops,
.of_match_table = flexcan_of_match,
},
.probe = flexcan_probe,
.remove = flexcan_remove,
.id_table = flexcan_id_table,
};
module_platform_driver(flexcan_driver);
MODULE_AUTHOR("Sascha Hauer <kernel@pengutronix.de>, "
"Marc Kleine-Budde <kernel@pengutronix.de>");
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("CAN port driver for flexcan based chip");