bus: sunxi-rsb: Add driver for Allwinner Reduced Serial Bus
Reduced Serial Bus (RSB) is an Allwinner proprietery interface used to communicate with PMICs and other peripheral ICs. RSB is a two-wire push-pull serial bus that supports 1 master device and up to 15 active slave devices. Signed-off-by: Chen-Yu Tsai <wens@csie.org> Reviewed-by: Mark Brown <broonie@kernel.org> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Olof Johansson <olof@lixom.net>
This commit is contained in:
Chen-Yu Tsai
Olof Johansson
parent
4a5705a9c2
commit
d787dcdb9c
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@ -121,6 +121,17 @@ config SIMPLE_PM_BUS
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Controller (BSC, sometimes called "LBSC within Bus Bridge", or
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"External Bus Interface") as found on several Renesas ARM SoCs.
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config SUNXI_RSB
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tristate "Allwinner sunXi Reduced Serial Bus Driver"
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default MACH_SUN8I || MACH_SUN9I
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depends on ARCH_SUNXI
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select REGMAP
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help
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Say y here to enable support for Allwinner's Reduced Serial Bus
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(RSB) support. This controller is responsible for communicating
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with various RSB based devices, such as AXP223, AXP8XX PMICs,
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and AC100/AC200 ICs.
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config VEXPRESS_CONFIG
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bool "Versatile Express configuration bus"
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default y if ARCH_VEXPRESS
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@ -15,5 +15,6 @@ obj-$(CONFIG_MVEBU_MBUS) += mvebu-mbus.o
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obj-$(CONFIG_OMAP_INTERCONNECT) += omap_l3_smx.o omap_l3_noc.o
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obj-$(CONFIG_OMAP_OCP2SCP) += omap-ocp2scp.o
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obj-$(CONFIG_SUNXI_RSB) += sunxi-rsb.o
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obj-$(CONFIG_SIMPLE_PM_BUS) += simple-pm-bus.o
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obj-$(CONFIG_VEXPRESS_CONFIG) += vexpress-config.o
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@ -0,0 +1,783 @@
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/*
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* RSB (Reduced Serial Bus) driver.
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*
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* Author: Chen-Yu Tsai <wens@csie.org>
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*
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* This file is licensed under the terms of the GNU General Public License
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* version 2. This program is licensed "as is" without any warranty of any
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* kind, whether express or implied.
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*
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* The RSB controller looks like an SMBus controller which only supports
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* byte and word data transfers. But, it differs from standard SMBus
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* protocol on several aspects:
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* - it uses addresses set at runtime to address slaves. Runtime addresses
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* are sent to slaves using their 12bit hardware addresses. Up to 15
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* runtime addresses are available.
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* - it adds a parity bit every 8bits of data and address for read and
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* write accesses; this replaces the ack bit
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* - only one read access is required to read a byte (instead of a write
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* followed by a read access in standard SMBus protocol)
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* - there's no Ack bit after each read access
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*
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* This means this bus cannot be used to interface with standard SMBus
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* devices. Devices known to support this interface include the AXP223,
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* AXP809, and AXP806 PMICs, and the AC100 audio codec, all from X-Powers.
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*
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* A description of the operation and wire protocol can be found in the
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* RSB section of Allwinner's A80 user manual, which can be found at
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*
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* https://github.com/allwinner-zh/documents/tree/master/A80
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*
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* This document is officially released by Allwinner.
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*
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* This driver is based on i2c-sun6i-p2wi.c, the P2WI bus driver.
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*
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*/
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#include <linux/clk.h>
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#include <linux/clk/clk-conf.h>
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#include <linux/device.h>
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#include <linux/interrupt.h>
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#include <linux/io.h>
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#include <linux/iopoll.h>
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#include <linux/module.h>
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#include <linux/of.h>
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#include <linux/of_irq.h>
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#include <linux/of_platform.h>
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#include <linux/platform_device.h>
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#include <linux/regmap.h>
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#include <linux/reset.h>
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#include <linux/slab.h>
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#include <linux/sunxi-rsb.h>
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#include <linux/types.h>
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/* RSB registers */
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#define RSB_CTRL 0x0 /* Global control */
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#define RSB_CCR 0x4 /* Clock control */
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#define RSB_INTE 0x8 /* Interrupt controls */
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#define RSB_INTS 0xc /* Interrupt status */
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#define RSB_ADDR 0x10 /* Address to send with read/write command */
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#define RSB_DATA 0x1c /* Data to read/write */
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#define RSB_LCR 0x24 /* Line control */
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#define RSB_DMCR 0x28 /* Device mode (init) control */
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#define RSB_CMD 0x2c /* RSB Command */
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#define RSB_DAR 0x30 /* Device address / runtime address */
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/* CTRL fields */
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#define RSB_CTRL_START_TRANS BIT(7)
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#define RSB_CTRL_ABORT_TRANS BIT(6)
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#define RSB_CTRL_GLOBAL_INT_ENB BIT(1)
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#define RSB_CTRL_SOFT_RST BIT(0)
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/* CLK CTRL fields */
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#define RSB_CCR_SDA_OUT_DELAY(v) (((v) & 0x7) << 8)
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#define RSB_CCR_MAX_CLK_DIV 0xff
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#define RSB_CCR_CLK_DIV(v) ((v) & RSB_CCR_MAX_CLK_DIV)
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/* STATUS fields */
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#define RSB_INTS_TRANS_ERR_ACK BIT(16)
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#define RSB_INTS_TRANS_ERR_DATA_BIT(v) (((v) >> 8) & 0xf)
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#define RSB_INTS_TRANS_ERR_DATA GENMASK(11, 8)
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#define RSB_INTS_LOAD_BSY BIT(2)
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#define RSB_INTS_TRANS_ERR BIT(1)
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#define RSB_INTS_TRANS_OVER BIT(0)
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/* LINE CTRL fields*/
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#define RSB_LCR_SCL_STATE BIT(5)
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#define RSB_LCR_SDA_STATE BIT(4)
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#define RSB_LCR_SCL_CTL BIT(3)
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#define RSB_LCR_SCL_CTL_EN BIT(2)
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#define RSB_LCR_SDA_CTL BIT(1)
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#define RSB_LCR_SDA_CTL_EN BIT(0)
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/* DEVICE MODE CTRL field values */
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#define RSB_DMCR_DEVICE_START BIT(31)
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#define RSB_DMCR_MODE_DATA (0x7c << 16)
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#define RSB_DMCR_MODE_REG (0x3e << 8)
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#define RSB_DMCR_DEV_ADDR 0x00
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/* CMD values */
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#define RSB_CMD_RD8 0x8b
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#define RSB_CMD_RD16 0x9c
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#define RSB_CMD_RD32 0xa6
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#define RSB_CMD_WR8 0x4e
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#define RSB_CMD_WR16 0x59
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#define RSB_CMD_WR32 0x63
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#define RSB_CMD_STRA 0xe8
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/* DAR fields */
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#define RSB_DAR_RTA(v) (((v) & 0xff) << 16)
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#define RSB_DAR_DA(v) ((v) & 0xffff)
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#define RSB_MAX_FREQ 20000000
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#define RSB_CTRL_NAME "sunxi-rsb"
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struct sunxi_rsb_addr_map {
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u16 hwaddr;
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u8 rtaddr;
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};
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struct sunxi_rsb {
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struct device *dev;
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void __iomem *regs;
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struct clk *clk;
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struct reset_control *rstc;
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struct completion complete;
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struct mutex lock;
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unsigned int status;
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};
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/* bus / slave device related functions */
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static struct bus_type sunxi_rsb_bus;
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static int sunxi_rsb_device_match(struct device *dev, struct device_driver *drv)
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{
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return of_driver_match_device(dev, drv);
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}
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static int sunxi_rsb_device_probe(struct device *dev)
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{
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const struct sunxi_rsb_driver *drv = to_sunxi_rsb_driver(dev->driver);
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struct sunxi_rsb_device *rdev = to_sunxi_rsb_device(dev);
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int ret;
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if (!drv->probe)
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return -ENODEV;
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if (!rdev->irq) {
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int irq = -ENOENT;
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if (dev->of_node)
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irq = of_irq_get(dev->of_node, 0);
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if (irq == -EPROBE_DEFER)
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return irq;
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if (irq < 0)
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irq = 0;
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rdev->irq = irq;
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}
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ret = of_clk_set_defaults(dev->of_node, false);
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if (ret < 0)
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return ret;
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return drv->probe(rdev);
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}
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static int sunxi_rsb_device_remove(struct device *dev)
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{
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const struct sunxi_rsb_driver *drv = to_sunxi_rsb_driver(dev->driver);
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return drv->remove(to_sunxi_rsb_device(dev));
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}
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static struct bus_type sunxi_rsb_bus = {
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.name = RSB_CTRL_NAME,
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.match = sunxi_rsb_device_match,
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.probe = sunxi_rsb_device_probe,
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.remove = sunxi_rsb_device_remove,
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};
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static void sunxi_rsb_dev_release(struct device *dev)
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{
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struct sunxi_rsb_device *rdev = to_sunxi_rsb_device(dev);
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kfree(rdev);
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}
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/**
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* sunxi_rsb_device_create() - allocate and add an RSB device
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* @rsb: RSB controller
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* @node: RSB slave device node
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* @hwaddr: RSB slave hardware address
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* @rtaddr: RSB slave runtime address
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*/
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static struct sunxi_rsb_device *sunxi_rsb_device_create(struct sunxi_rsb *rsb,
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struct device_node *node, u16 hwaddr, u8 rtaddr)
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{
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int err;
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struct sunxi_rsb_device *rdev;
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rdev = kzalloc(sizeof(*rdev), GFP_KERNEL);
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if (!rdev)
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return ERR_PTR(-ENOMEM);
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rdev->rsb = rsb;
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rdev->hwaddr = hwaddr;
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rdev->rtaddr = rtaddr;
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rdev->dev.bus = &sunxi_rsb_bus;
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rdev->dev.parent = rsb->dev;
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rdev->dev.of_node = node;
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rdev->dev.release = sunxi_rsb_dev_release;
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dev_set_name(&rdev->dev, "%s-%x", RSB_CTRL_NAME, hwaddr);
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err = device_register(&rdev->dev);
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if (err < 0) {
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dev_err(&rdev->dev, "Can't add %s, status %d\n",
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dev_name(&rdev->dev), err);
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goto err_device_add;
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}
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dev_dbg(&rdev->dev, "device %s registered\n", dev_name(&rdev->dev));
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err_device_add:
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put_device(&rdev->dev);
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return ERR_PTR(err);
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}
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/**
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* sunxi_rsb_device_unregister(): unregister an RSB device
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* @rdev: rsb_device to be removed
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*/
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static void sunxi_rsb_device_unregister(struct sunxi_rsb_device *rdev)
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{
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device_unregister(&rdev->dev);
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}
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static int sunxi_rsb_remove_devices(struct device *dev, void *data)
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{
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struct sunxi_rsb_device *rdev = to_sunxi_rsb_device(dev);
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if (dev->bus == &sunxi_rsb_bus)
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sunxi_rsb_device_unregister(rdev);
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return 0;
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}
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/**
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* sunxi_rsb_driver_register() - Register device driver with RSB core
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* @rdrv: device driver to be associated with slave-device.
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*
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* This API will register the client driver with the RSB framework.
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* It is typically called from the driver's module-init function.
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*/
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int sunxi_rsb_driver_register(struct sunxi_rsb_driver *rdrv)
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{
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rdrv->driver.bus = &sunxi_rsb_bus;
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return driver_register(&rdrv->driver);
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}
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EXPORT_SYMBOL_GPL(sunxi_rsb_driver_register);
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/* common code that starts a transfer */
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static int _sunxi_rsb_run_xfer(struct sunxi_rsb *rsb)
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{
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if (readl(rsb->regs + RSB_CTRL) & RSB_CTRL_START_TRANS) {
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dev_dbg(rsb->dev, "RSB transfer still in progress\n");
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return -EBUSY;
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}
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reinit_completion(&rsb->complete);
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writel(RSB_INTS_LOAD_BSY | RSB_INTS_TRANS_ERR | RSB_INTS_TRANS_OVER,
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rsb->regs + RSB_INTE);
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writel(RSB_CTRL_START_TRANS | RSB_CTRL_GLOBAL_INT_ENB,
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rsb->regs + RSB_CTRL);
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if (!wait_for_completion_io_timeout(&rsb->complete,
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msecs_to_jiffies(100))) {
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dev_dbg(rsb->dev, "RSB timeout\n");
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/* abort the transfer */
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writel(RSB_CTRL_ABORT_TRANS, rsb->regs + RSB_CTRL);
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/* clear any interrupt flags */
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writel(readl(rsb->regs + RSB_INTS), rsb->regs + RSB_INTS);
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return -ETIMEDOUT;
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}
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if (rsb->status & RSB_INTS_LOAD_BSY) {
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dev_dbg(rsb->dev, "RSB busy\n");
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return -EBUSY;
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}
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if (rsb->status & RSB_INTS_TRANS_ERR) {
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if (rsb->status & RSB_INTS_TRANS_ERR_ACK) {
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dev_dbg(rsb->dev, "RSB slave nack\n");
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return -EINVAL;
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}
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if (rsb->status & RSB_INTS_TRANS_ERR_DATA) {
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dev_dbg(rsb->dev, "RSB transfer data error\n");
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return -EIO;
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}
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}
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return 0;
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}
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static int sunxi_rsb_read(struct sunxi_rsb *rsb, u8 rtaddr, u8 addr,
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u32 *buf, size_t len)
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{
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u32 cmd;
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int ret;
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if (!buf)
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return -EINVAL;
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switch (len) {
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case 1:
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cmd = RSB_CMD_RD8;
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break;
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case 2:
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cmd = RSB_CMD_RD16;
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break;
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case 4:
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cmd = RSB_CMD_RD32;
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break;
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default:
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dev_err(rsb->dev, "Invalid access width: %d\n", len);
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return -EINVAL;
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}
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mutex_lock(&rsb->lock);
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writel(addr, rsb->regs + RSB_ADDR);
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writel(RSB_DAR_RTA(rtaddr), rsb->regs + RSB_DAR);
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writel(cmd, rsb->regs + RSB_CMD);
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ret = _sunxi_rsb_run_xfer(rsb);
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if (ret)
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goto out;
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*buf = readl(rsb->regs + RSB_DATA);
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mutex_unlock(&rsb->lock);
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out:
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return ret;
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}
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static int sunxi_rsb_write(struct sunxi_rsb *rsb, u8 rtaddr, u8 addr,
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const u32 *buf, size_t len)
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{
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u32 cmd;
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int ret;
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if (!buf)
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return -EINVAL;
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switch (len) {
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case 1:
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cmd = RSB_CMD_WR8;
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break;
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case 2:
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cmd = RSB_CMD_WR16;
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break;
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case 4:
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cmd = RSB_CMD_WR32;
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break;
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default:
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dev_err(rsb->dev, "Invalid access width: %d\n", len);
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return -EINVAL;
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}
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mutex_lock(&rsb->lock);
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writel(addr, rsb->regs + RSB_ADDR);
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writel(RSB_DAR_RTA(rtaddr), rsb->regs + RSB_DAR);
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writel(*buf, rsb->regs + RSB_DATA);
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writel(cmd, rsb->regs + RSB_CMD);
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ret = _sunxi_rsb_run_xfer(rsb);
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mutex_unlock(&rsb->lock);
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return ret;
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}
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/* RSB regmap functions */
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struct sunxi_rsb_ctx {
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struct sunxi_rsb_device *rdev;
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int size;
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};
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static int regmap_sunxi_rsb_reg_read(void *context, unsigned int reg,
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unsigned int *val)
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{
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struct sunxi_rsb_ctx *ctx = context;
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struct sunxi_rsb_device *rdev = ctx->rdev;
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if (reg > 0xff)
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return -EINVAL;
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return sunxi_rsb_read(rdev->rsb, rdev->rtaddr, reg, val, ctx->size);
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}
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static int regmap_sunxi_rsb_reg_write(void *context, unsigned int reg,
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unsigned int val)
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{
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struct sunxi_rsb_ctx *ctx = context;
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struct sunxi_rsb_device *rdev = ctx->rdev;
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return sunxi_rsb_write(rdev->rsb, rdev->rtaddr, reg, &val, ctx->size);
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}
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static void regmap_sunxi_rsb_free_ctx(void *context)
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{
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struct sunxi_rsb_ctx *ctx = context;
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kfree(ctx);
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}
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static struct regmap_bus regmap_sunxi_rsb = {
|
||||
.reg_write = regmap_sunxi_rsb_reg_write,
|
||||
.reg_read = regmap_sunxi_rsb_reg_read,
|
||||
.free_context = regmap_sunxi_rsb_free_ctx,
|
||||
.reg_format_endian_default = REGMAP_ENDIAN_NATIVE,
|
||||
.val_format_endian_default = REGMAP_ENDIAN_NATIVE,
|
||||
};
|
||||
|
||||
static struct sunxi_rsb_ctx *regmap_sunxi_rsb_init_ctx(struct sunxi_rsb_device *rdev,
|
||||
const struct regmap_config *config)
|
||||
{
|
||||
struct sunxi_rsb_ctx *ctx;
|
||||
|
||||
switch (config->val_bits) {
|
||||
case 8:
|
||||
case 16:
|
||||
case 32:
|
||||
break;
|
||||
default:
|
||||
return ERR_PTR(-EINVAL);
|
||||
}
|
||||
|
||||
ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
|
||||
if (!ctx)
|
||||
return ERR_PTR(-ENOMEM);
|
||||
|
||||
ctx->rdev = rdev;
|
||||
ctx->size = config->val_bits / 8;
|
||||
|
||||
return ctx;
|
||||
}
|
||||
|
||||
struct regmap *__devm_regmap_init_sunxi_rsb(struct sunxi_rsb_device *rdev,
|
||||
const struct regmap_config *config,
|
||||
struct lock_class_key *lock_key,
|
||||
const char *lock_name)
|
||||
{
|
||||
struct sunxi_rsb_ctx *ctx = regmap_sunxi_rsb_init_ctx(rdev, config);
|
||||
|
||||
if (IS_ERR(ctx))
|
||||
return ERR_CAST(ctx);
|
||||
|
||||
return __devm_regmap_init(&rdev->dev, ®map_sunxi_rsb, ctx, config,
|
||||
lock_key, lock_name);
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(__devm_regmap_init_sunxi_rsb);
|
||||
|
||||
/* RSB controller driver functions */
|
||||
static irqreturn_t sunxi_rsb_irq(int irq, void *dev_id)
|
||||
{
|
||||
struct sunxi_rsb *rsb = dev_id;
|
||||
u32 status;
|
||||
|
||||
status = readl(rsb->regs + RSB_INTS);
|
||||
rsb->status = status;
|
||||
|
||||
/* Clear interrupts */
|
||||
status &= (RSB_INTS_LOAD_BSY | RSB_INTS_TRANS_ERR |
|
||||
RSB_INTS_TRANS_OVER);
|
||||
writel(status, rsb->regs + RSB_INTS);
|
||||
|
||||
complete(&rsb->complete);
|
||||
|
||||
return IRQ_HANDLED;
|
||||
}
|
||||
|
||||
static int sunxi_rsb_init_device_mode(struct sunxi_rsb *rsb)
|
||||
{
|
||||
int ret = 0;
|
||||
u32 reg;
|
||||
|
||||
/* send init sequence */
|
||||
writel(RSB_DMCR_DEVICE_START | RSB_DMCR_MODE_DATA |
|
||||
RSB_DMCR_MODE_REG | RSB_DMCR_DEV_ADDR, rsb->regs + RSB_DMCR);
|
||||
|
||||
readl_poll_timeout(rsb->regs + RSB_DMCR, reg,
|
||||
!(reg & RSB_DMCR_DEVICE_START), 100, 250000);
|
||||
if (reg & RSB_DMCR_DEVICE_START)
|
||||
ret = -ETIMEDOUT;
|
||||
|
||||
/* clear interrupt status bits */
|
||||
writel(readl(rsb->regs + RSB_INTS), rsb->regs + RSB_INTS);
|
||||
|
||||
return ret;
|
||||
}
|
||||
|
||||
/*
|
||||
* There are 15 valid runtime addresses, though Allwinner typically
|
||||
* skips the first, for unknown reasons, and uses the following three.
|
||||
*
|
||||
* 0x17, 0x2d, 0x3a, 0x4e, 0x59, 0x63, 0x74, 0x8b,
|
||||
* 0x9c, 0xa6, 0xb1, 0xc5, 0xd2, 0xe8, 0xff
|
||||
*
|
||||
* No designs with 2 RSB slave devices sharing identical hardware
|
||||
* addresses on the same bus have been seen in the wild. All designs
|
||||
* use 0x2d for the primary PMIC, 0x3a for the secondary PMIC if
|
||||
* there is one, and 0x45 for peripheral ICs.
|
||||
*
|
||||
* The hardware does not seem to support re-setting runtime addresses.
|
||||
* Attempts to do so result in the slave devices returning a NACK.
|
||||
* Hence we just hardcode the mapping here, like Allwinner does.
|
||||
*/
|
||||
|
||||
static const struct sunxi_rsb_addr_map sunxi_rsb_addr_maps[] = {
|
||||
{ 0x3e3, 0x2d }, /* Primary PMIC: AXP223, AXP809, AXP81X, ... */
|
||||
{ 0x745, 0x3a }, /* Secondary PMIC: AXP806, ... */
|
||||
{ 0xe89, 0x45 }, /* Peripheral IC: AC100, ... */
|
||||
};
|
||||
|
||||
static u8 sunxi_rsb_get_rtaddr(u16 hwaddr)
|
||||
{
|
||||
int i;
|
||||
|
||||
for (i = 0; i < ARRAY_SIZE(sunxi_rsb_addr_maps); i++)
|
||||
if (hwaddr == sunxi_rsb_addr_maps[i].hwaddr)
|
||||
return sunxi_rsb_addr_maps[i].rtaddr;
|
||||
|
||||
return 0; /* 0 is an invalid runtime address */
|
||||
}
|
||||
|
||||
static int of_rsb_register_devices(struct sunxi_rsb *rsb)
|
||||
{
|
||||
struct device *dev = rsb->dev;
|
||||
struct device_node *child, *np = dev->of_node;
|
||||
u32 hwaddr;
|
||||
u8 rtaddr;
|
||||
int ret;
|
||||
|
||||
if (!np)
|
||||
return -EINVAL;
|
||||
|
||||
/* Runtime addresses for all slaves should be set first */
|
||||
for_each_available_child_of_node(np, child) {
|
||||
dev_dbg(dev, "setting child %s runtime address\n",
|
||||
child->full_name);
|
||||
|
||||
ret = of_property_read_u32(child, "reg", &hwaddr);
|
||||
if (ret) {
|
||||
dev_err(dev, "%s: invalid 'reg' property: %d\n",
|
||||
child->full_name, ret);
|
||||
continue;
|
||||
}
|
||||
|
||||
rtaddr = sunxi_rsb_get_rtaddr(hwaddr);
|
||||
if (!rtaddr) {
|
||||
dev_err(dev, "%s: unknown hardware device address\n",
|
||||
child->full_name);
|
||||
continue;
|
||||
}
|
||||
|
||||
/*
|
||||
* Since no devices have been registered yet, we are the
|
||||
* only ones using the bus, we can skip locking the bus.
|
||||
*/
|
||||
|
||||
/* setup command parameters */
|
||||
writel(RSB_CMD_STRA, rsb->regs + RSB_CMD);
|
||||
writel(RSB_DAR_RTA(rtaddr) | RSB_DAR_DA(hwaddr),
|
||||
rsb->regs + RSB_DAR);
|
||||
|
||||
/* send command */
|
||||
ret = _sunxi_rsb_run_xfer(rsb);
|
||||
if (ret)
|
||||
dev_warn(dev, "%s: set runtime address failed: %d\n",
|
||||
child->full_name, ret);
|
||||
}
|
||||
|
||||
/* Then we start adding devices and probing them */
|
||||
for_each_available_child_of_node(np, child) {
|
||||
struct sunxi_rsb_device *rdev;
|
||||
|
||||
dev_dbg(dev, "adding child %s\n", child->full_name);
|
||||
|
||||
ret = of_property_read_u32(child, "reg", &hwaddr);
|
||||
if (ret)
|
||||
continue;
|
||||
|
||||
rtaddr = sunxi_rsb_get_rtaddr(hwaddr);
|
||||
if (!rtaddr)
|
||||
continue;
|
||||
|
||||
rdev = sunxi_rsb_device_create(rsb, child, hwaddr, rtaddr);
|
||||
if (IS_ERR(rdev))
|
||||
dev_err(dev, "failed to add child device %s: %ld\n",
|
||||
child->full_name, PTR_ERR(rdev));
|
||||
}
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static const struct of_device_id sunxi_rsb_of_match_table[] = {
|
||||
{ .compatible = "allwinner,sun8i-a23-rsb" },
|
||||
{}
|
||||
};
|
||||
MODULE_DEVICE_TABLE(of, sunxi_rsb_of_match_table);
|
||||
|
||||
static int sunxi_rsb_probe(struct platform_device *pdev)
|
||||
{
|
||||
struct device *dev = &pdev->dev;
|
||||
struct device_node *np = dev->of_node;
|
||||
struct resource *r;
|
||||
struct sunxi_rsb *rsb;
|
||||
unsigned long p_clk_freq;
|
||||
u32 clk_delay, clk_freq = 3000000;
|
||||
int clk_div, irq, ret;
|
||||
u32 reg;
|
||||
|
||||
of_property_read_u32(np, "clock-frequency", &clk_freq);
|
||||
if (clk_freq > RSB_MAX_FREQ) {
|
||||
dev_err(dev,
|
||||
"clock-frequency (%u Hz) is too high (max = 20MHz)\n",
|
||||
clk_freq);
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
rsb = devm_kzalloc(dev, sizeof(*rsb), GFP_KERNEL);
|
||||
if (!rsb)
|
||||
return -ENOMEM;
|
||||
|
||||
rsb->dev = dev;
|
||||
platform_set_drvdata(pdev, rsb);
|
||||
r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
|
||||
rsb->regs = devm_ioremap_resource(dev, r);
|
||||
if (IS_ERR(rsb->regs))
|
||||
return PTR_ERR(rsb->regs);
|
||||
|
||||
irq = platform_get_irq(pdev, 0);
|
||||
if (irq < 0) {
|
||||
dev_err(dev, "failed to retrieve irq: %d\n", irq);
|
||||
return irq;
|
||||
}
|
||||
|
||||
rsb->clk = devm_clk_get(dev, NULL);
|
||||
if (IS_ERR(rsb->clk)) {
|
||||
ret = PTR_ERR(rsb->clk);
|
||||
dev_err(dev, "failed to retrieve clk: %d\n", ret);
|
||||
return ret;
|
||||
}
|
||||
|
||||
ret = clk_prepare_enable(rsb->clk);
|
||||
if (ret) {
|
||||
dev_err(dev, "failed to enable clk: %d\n", ret);
|
||||
return ret;
|
||||
}
|
||||
|
||||
p_clk_freq = clk_get_rate(rsb->clk);
|
||||
|
||||
rsb->rstc = devm_reset_control_get(dev, NULL);
|
||||
if (IS_ERR(rsb->rstc)) {
|
||||
ret = PTR_ERR(rsb->rstc);
|
||||
dev_err(dev, "failed to retrieve reset controller: %d\n", ret);
|
||||
goto err_clk_disable;
|
||||
}
|
||||
|
||||
ret = reset_control_deassert(rsb->rstc);
|
||||
if (ret) {
|
||||
dev_err(dev, "failed to deassert reset line: %d\n", ret);
|
||||
goto err_clk_disable;
|
||||
}
|
||||
|
||||
init_completion(&rsb->complete);
|
||||
mutex_init(&rsb->lock);
|
||||
|
||||
/* reset the controller */
|
||||
writel(RSB_CTRL_SOFT_RST, rsb->regs + RSB_CTRL);
|
||||
readl_poll_timeout(rsb->regs + RSB_CTRL, reg,
|
||||
!(reg & RSB_CTRL_SOFT_RST), 1000, 100000);
|
||||
|
||||
/*
|
||||
* Clock frequency and delay calculation code is from
|
||||
* Allwinner U-boot sources.
|
||||
*
|
||||
* From A83 user manual:
|
||||
* bus clock frequency = parent clock frequency / (2 * (divider + 1))
|
||||
*/
|
||||
clk_div = p_clk_freq / clk_freq / 2;
|
||||
if (!clk_div)
|
||||
clk_div = 1;
|
||||
else if (clk_div > RSB_CCR_MAX_CLK_DIV + 1)
|
||||
clk_div = RSB_CCR_MAX_CLK_DIV + 1;
|
||||
|
||||
clk_delay = clk_div >> 1;
|
||||
if (!clk_delay)
|
||||
clk_delay = 1;
|
||||
|
||||
dev_info(dev, "RSB running at %lu Hz\n", p_clk_freq / clk_div / 2);
|
||||
writel(RSB_CCR_SDA_OUT_DELAY(clk_delay) | RSB_CCR_CLK_DIV(clk_div - 1),
|
||||
rsb->regs + RSB_CCR);
|
||||
|
||||
ret = devm_request_irq(dev, irq, sunxi_rsb_irq, 0, RSB_CTRL_NAME, rsb);
|
||||
if (ret) {
|
||||
dev_err(dev, "can't register interrupt handler irq %d: %d\n",
|
||||
irq, ret);
|
||||
goto err_reset_assert;
|
||||
}
|
||||
|
||||
/* initialize all devices on the bus into RSB mode */
|
||||
ret = sunxi_rsb_init_device_mode(rsb);
|
||||
if (ret)
|
||||
dev_warn(dev, "Initialize device mode failed: %d\n", ret);
|
||||
|
||||
of_rsb_register_devices(rsb);
|
||||
|
||||
return 0;
|
||||
|
||||
err_reset_assert:
|
||||
reset_control_assert(rsb->rstc);
|
||||
|
||||
err_clk_disable:
|
||||
clk_disable_unprepare(rsb->clk);
|
||||
|
||||
return ret;
|
||||
}
|
||||
|
||||
static int sunxi_rsb_remove(struct platform_device *pdev)
|
||||
{
|
||||
struct sunxi_rsb *rsb = platform_get_drvdata(pdev);
|
||||
|
||||
device_for_each_child(rsb->dev, NULL, sunxi_rsb_remove_devices);
|
||||
reset_control_assert(rsb->rstc);
|
||||
clk_disable_unprepare(rsb->clk);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static struct platform_driver sunxi_rsb_driver = {
|
||||
.probe = sunxi_rsb_probe,
|
||||
.remove = sunxi_rsb_remove,
|
||||
.driver = {
|
||||
.name = RSB_CTRL_NAME,
|
||||
.of_match_table = sunxi_rsb_of_match_table,
|
||||
},
|
||||
};
|
||||
|
||||
static int __init sunxi_rsb_init(void)
|
||||
{
|
||||
int ret;
|
||||
|
||||
ret = bus_register(&sunxi_rsb_bus);
|
||||
if (ret) {
|
||||
pr_err("failed to register sunxi sunxi_rsb bus: %d\n", ret);
|
||||
return ret;
|
||||
}
|
||||
|
||||
return platform_driver_register(&sunxi_rsb_driver);
|
||||
}
|
||||
module_init(sunxi_rsb_init);
|
||||
|
||||
static void __exit sunxi_rsb_exit(void)
|
||||
{
|
||||
platform_driver_unregister(&sunxi_rsb_driver);
|
||||
bus_unregister(&sunxi_rsb_bus);
|
||||
}
|
||||
module_exit(sunxi_rsb_exit);
|
||||
|
||||
MODULE_AUTHOR("Chen-Yu Tsai <wens@csie.org>");
|
||||
MODULE_DESCRIPTION("Allwinner sunXi Reduced Serial Bus controller driver");
|
||||
MODULE_LICENSE("GPL v2");
|
||||
|
|
@ -0,0 +1,105 @@
|
|||
/*
|
||||
* Allwinner Reduced Serial Bus Driver
|
||||
*
|
||||
* Copyright (c) 2015 Chen-Yu Tsai
|
||||
*
|
||||
* Author: Chen-Yu Tsai <wens@csie.org>
|
||||
*
|
||||
* This file is licensed under the terms of the GNU General Public
|
||||
* License version 2. This program is licensed "as is" without any
|
||||
* warranty of any kind, whether express or implied.
|
||||
*/
|
||||
#ifndef _SUNXI_RSB_H
|
||||
#define _SUNXI_RSB_H
|
||||
|
||||
#include <linux/device.h>
|
||||
#include <linux/regmap.h>
|
||||
#include <linux/types.h>
|
||||
|
||||
struct sunxi_rsb;
|
||||
|
||||
/**
|
||||
* struct sunxi_rsb_device - Basic representation of an RSB device
|
||||
* @dev: Driver model representation of the device.
|
||||
* @ctrl: RSB controller managing the bus hosting this device.
|
||||
* @rtaddr: This device's runtime address
|
||||
* @hwaddr: This device's hardware address
|
||||
*/
|
||||
struct sunxi_rsb_device {
|
||||
struct device dev;
|
||||
struct sunxi_rsb *rsb;
|
||||
int irq;
|
||||
u8 rtaddr;
|
||||
u16 hwaddr;
|
||||
};
|
||||
|
||||
static inline struct sunxi_rsb_device *to_sunxi_rsb_device(struct device *d)
|
||||
{
|
||||
return container_of(d, struct sunxi_rsb_device, dev);
|
||||
}
|
||||
|
||||
static inline void *sunxi_rsb_device_get_drvdata(const struct sunxi_rsb_device *rdev)
|
||||
{
|
||||
return dev_get_drvdata(&rdev->dev);
|
||||
}
|
||||
|
||||
static inline void sunxi_rsb_device_set_drvdata(struct sunxi_rsb_device *rdev,
|
||||
void *data)
|
||||
{
|
||||
dev_set_drvdata(&rdev->dev, data);
|
||||
}
|
||||
|
||||
/**
|
||||
* struct sunxi_rsb_driver - RSB slave device driver
|
||||
* @driver: RSB device drivers should initialize name and owner field of
|
||||
* this structure.
|
||||
* @probe: binds this driver to a RSB device.
|
||||
* @remove: unbinds this driver from the RSB device.
|
||||
*/
|
||||
struct sunxi_rsb_driver {
|
||||
struct device_driver driver;
|
||||
int (*probe)(struct sunxi_rsb_device *rdev);
|
||||
int (*remove)(struct sunxi_rsb_device *rdev);
|
||||
};
|
||||
|
||||
static inline struct sunxi_rsb_driver *to_sunxi_rsb_driver(struct device_driver *d)
|
||||
{
|
||||
return container_of(d, struct sunxi_rsb_driver, driver);
|
||||
}
|
||||
|
||||
int sunxi_rsb_driver_register(struct sunxi_rsb_driver *rdrv);
|
||||
|
||||
/**
|
||||
* sunxi_rsb_driver_unregister() - unregister an RSB client driver
|
||||
* @rdrv: the driver to unregister
|
||||
*/
|
||||
static inline void sunxi_rsb_driver_unregister(struct sunxi_rsb_driver *rdrv)
|
||||
{
|
||||
if (rdrv)
|
||||
driver_unregister(&rdrv->driver);
|
||||
}
|
||||
|
||||
#define module_sunxi_rsb_driver(__sunxi_rsb_driver) \
|
||||
module_driver(__sunxi_rsb_driver, sunxi_rsb_driver_register, \
|
||||
sunxi_rsb_driver_unregister)
|
||||
|
||||
struct regmap *__devm_regmap_init_sunxi_rsb(struct sunxi_rsb_device *rdev,
|
||||
const struct regmap_config *config,
|
||||
struct lock_class_key *lock_key,
|
||||
const char *lock_name);
|
||||
|
||||
/**
|
||||
* devm_regmap_init_sunxi_rsb(): Initialise managed register map
|
||||
*
|
||||
* @rdev: Device that will be interacted with
|
||||
* @config: Configuration for register map
|
||||
*
|
||||
* The return value will be an ERR_PTR() on error or a valid pointer
|
||||
* to a struct regmap. The regmap will be automatically freed by the
|
||||
* device management code.
|
||||
*/
|
||||
#define devm_regmap_init_sunxi_rsb(rdev, config) \
|
||||
__regmap_lockdep_wrapper(__devm_regmap_init_sunxi_rsb, #config, \
|
||||
rdev, config)
|
||||
|
||||
#endif /* _SUNXI_RSB_H */
|
||||
Loading…
Reference in New Issue