can: cc770: add platform bus driver for the CC770 and AN82527
This driver works with both, static platform data and device tree bindings. It has been tested on a TQM855L board with two AN82527 CAN controllers on the local bus. CC: Devicetree-discuss@lists.ozlabs.org CC: linuxppc-dev@ozlabs.org CC: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Wolfgang Grandegger <wg@grandegger.com> Acked-by: Marc Kleine-Budde <mkl@pengutronix.de> Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Wolfgang Grandegger
David S. Miller
parent
edd2c26ffb
commit
e285e44d91
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@ -0,0 +1,53 @@
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Memory mapped Bosch CC770 and Intel AN82527 CAN controller
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Note: The CC770 is a CAN controller from Bosch, which is 100%
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compatible with the old AN82527 from Intel, but with "bugs" being fixed.
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Required properties:
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- compatible : should be "bosch,cc770" for the CC770 and "intc,82527"
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for the AN82527.
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- reg : should specify the chip select, address offset and size required
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to map the registers of the controller. The size is usually 0x80.
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- interrupts : property with a value describing the interrupt source
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(number and sensitivity) required for the controller.
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Optional properties:
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- bosch,external-clock-frequency : frequency of the external oscillator
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clock in Hz. Note that the internal clock frequency used by the
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controller is half of that value. If not specified, a default
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value of 16000000 (16 MHz) is used.
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- bosch,clock-out-frequency : slock frequency in Hz on the CLKOUT pin.
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If not specified or if the specified value is 0, the CLKOUT pin
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will be disabled.
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- bosch,slew-rate : slew rate of the CLKOUT signal. If not specified,
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a resonable value will be calculated.
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- bosch,disconnect-rx0-input : see data sheet.
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- bosch,disconnect-rx1-input : see data sheet.
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- bosch,disconnect-tx1-output : see data sheet.
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- bosch,polarity-dominant : see data sheet.
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- bosch,divide-memory-clock : see data sheet.
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- bosch,iso-low-speed-mux : see data sheet.
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For further information, please have a look to the CC770 or AN82527.
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Examples:
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can@3,100 {
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compatible = "bosch,cc770";
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reg = <3 0x100 0x80>;
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interrupts = <2 0>;
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interrupt-parent = <&mpic>;
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bosch,external-clock-frequency = <16000000>;
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};
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@ -11,4 +11,11 @@ config CAN_CC770_ISA
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connected to the ISA bus using I/O port, memory mapped or
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indirect access.
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config CAN_CC770_PLATFORM
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tristate "Generic Platform Bus based CC770 driver"
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---help---
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This driver adds support for the CC770 and AN82527 chips
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connected to the "platform bus" (Linux abstraction for directly
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to the processor attached devices).
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endif
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@ -4,5 +4,6 @@
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obj-$(CONFIG_CAN_CC770) += cc770.o
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obj-$(CONFIG_CAN_CC770_ISA) += cc770_isa.o
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obj-$(CONFIG_CAN_CC770_PLATFORM) += cc770_platform.o
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ccflags-$(CONFIG_CAN_DEBUG_DEVICES) := -DDEBUG
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@ -0,0 +1,272 @@
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/*
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* Driver for CC770 and AN82527 CAN controllers on the platform bus
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*
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* Copyright (C) 2009, 2011 Wolfgang Grandegger <wg@grandegger.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the version 2 of the GNU General Public License
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* as published by the Free Software Foundation
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*/
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/*
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* If platform data are used you should have similar definitions
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* in your board-specific code:
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*
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* static struct cc770_platform_data myboard_cc770_pdata = {
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* .osc_freq = 16000000,
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* .cir = 0x41,
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* .cor = 0x20,
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* .bcr = 0x40,
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* };
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*
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* Please see include/linux/can/platform/cc770.h for description of
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* above fields.
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*
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* If the device tree is used, you need a CAN node definition in your
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* DTS file similar to:
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*
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* can@3,100 {
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* compatible = "bosch,cc770";
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* reg = <3 0x100 0x80>;
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* interrupts = <2 0>;
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* interrupt-parent = <&mpic>;
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* bosch,external-clock-frequency = <16000000>;
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* };
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*
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* See "Documentation/devicetree/bindings/net/can/cc770.txt" for further
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* information.
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/interrupt.h>
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#include <linux/netdevice.h>
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#include <linux/delay.h>
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#include <linux/platform_device.h>
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#include <linux/of.h>
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#include <linux/can.h>
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#include <linux/can/dev.h>
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#include <linux/can/platform/cc770.h>
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#include "cc770.h"
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#define DRV_NAME "cc770_platform"
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MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
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MODULE_DESCRIPTION("Socket-CAN driver for CC770 on the platform bus");
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MODULE_LICENSE("GPL v2");
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#define CC770_PLATFORM_CAN_CLOCK 16000000
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static u8 cc770_platform_read_reg(const struct cc770_priv *priv, int reg)
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{
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return ioread8(priv->reg_base + reg);
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}
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static void cc770_platform_write_reg(const struct cc770_priv *priv, int reg,
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u8 val)
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{
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iowrite8(val, priv->reg_base + reg);
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}
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static int __devinit cc770_get_of_node_data(struct platform_device *pdev,
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struct cc770_priv *priv)
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{
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struct device_node *np = pdev->dev.of_node;
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const u32 *prop;
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int prop_size;
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u32 clkext;
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prop = of_get_property(np, "bosch,external-clock-frequency",
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&prop_size);
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if (prop && (prop_size == sizeof(u32)))
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clkext = *prop;
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else
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clkext = CC770_PLATFORM_CAN_CLOCK; /* default */
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priv->can.clock.freq = clkext;
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/* The system clock may not exceed 10 MHz */
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if (priv->can.clock.freq > 10000000) {
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priv->cpu_interface |= CPUIF_DSC;
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priv->can.clock.freq /= 2;
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}
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/* The memory clock may not exceed 8 MHz */
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if (priv->can.clock.freq > 8000000)
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priv->cpu_interface |= CPUIF_DMC;
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if (of_get_property(np, "bosch,divide-memory-clock", NULL))
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priv->cpu_interface |= CPUIF_DMC;
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if (of_get_property(np, "bosch,iso-low-speed-mux", NULL))
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priv->cpu_interface |= CPUIF_MUX;
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if (!of_get_property(np, "bosch,no-comperator-bypass", NULL))
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priv->bus_config |= BUSCFG_CBY;
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if (of_get_property(np, "bosch,disconnect-rx0-input", NULL))
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priv->bus_config |= BUSCFG_DR0;
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if (of_get_property(np, "bosch,disconnect-rx1-input", NULL))
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priv->bus_config |= BUSCFG_DR1;
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if (of_get_property(np, "bosch,disconnect-tx1-output", NULL))
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priv->bus_config |= BUSCFG_DT1;
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if (of_get_property(np, "bosch,polarity-dominant", NULL))
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priv->bus_config |= BUSCFG_POL;
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prop = of_get_property(np, "bosch,clock-out-frequency", &prop_size);
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if (prop && (prop_size == sizeof(u32)) && *prop > 0) {
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u32 cdv = clkext / *prop;
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int slew;
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if (cdv > 0 && cdv < 16) {
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priv->cpu_interface |= CPUIF_CEN;
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priv->clkout |= (cdv - 1) & CLKOUT_CD_MASK;
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prop = of_get_property(np, "bosch,slew-rate",
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&prop_size);
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if (prop && (prop_size == sizeof(u32))) {
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slew = *prop;
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} else {
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/* Determine default slew rate */
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slew = (CLKOUT_SL_MASK >>
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CLKOUT_SL_SHIFT) -
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((cdv * clkext - 1) / 8000000);
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if (slew < 0)
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slew = 0;
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}
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priv->clkout |= (slew << CLKOUT_SL_SHIFT) &
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CLKOUT_SL_MASK;
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} else {
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dev_dbg(&pdev->dev, "invalid clock-out-frequency\n");
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}
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}
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return 0;
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}
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static int __devinit cc770_get_platform_data(struct platform_device *pdev,
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struct cc770_priv *priv)
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{
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struct cc770_platform_data *pdata = pdev->dev.platform_data;
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priv->can.clock.freq = pdata->osc_freq;
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if (priv->cpu_interface | CPUIF_DSC)
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priv->can.clock.freq /= 2;
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priv->clkout = pdata->cor;
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priv->bus_config = pdata->bcr;
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priv->cpu_interface = pdata->cir;
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return 0;
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}
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static int __devinit cc770_platform_probe(struct platform_device *pdev)
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{
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struct net_device *dev;
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struct cc770_priv *priv;
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struct resource *mem;
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resource_size_t mem_size;
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void __iomem *base;
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int err, irq;
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mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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irq = platform_get_irq(pdev, 0);
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if (!mem || irq <= 0)
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return -ENODEV;
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mem_size = resource_size(mem);
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if (!request_mem_region(mem->start, mem_size, pdev->name))
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return -EBUSY;
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base = ioremap(mem->start, mem_size);
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if (!base) {
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err = -ENOMEM;
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goto exit_release_mem;
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}
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dev = alloc_cc770dev(0);
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if (!dev) {
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err = -ENOMEM;
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goto exit_unmap_mem;
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}
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dev->irq = irq;
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priv = netdev_priv(dev);
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priv->read_reg = cc770_platform_read_reg;
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priv->write_reg = cc770_platform_write_reg;
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priv->irq_flags = IRQF_SHARED;
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priv->reg_base = base;
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if (pdev->dev.of_node)
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err = cc770_get_of_node_data(pdev, priv);
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else if (pdev->dev.platform_data)
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err = cc770_get_platform_data(pdev, priv);
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else
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err = -ENODEV;
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if (err)
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goto exit_free_cc770;
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dev_dbg(&pdev->dev,
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"reg_base=0x%p irq=%d clock=%d cpu_interface=0x%02x "
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"bus_config=0x%02x clkout=0x%02x\n",
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priv->reg_base, dev->irq, priv->can.clock.freq,
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priv->cpu_interface, priv->bus_config, priv->clkout);
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dev_set_drvdata(&pdev->dev, dev);
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SET_NETDEV_DEV(dev, &pdev->dev);
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err = register_cc770dev(dev);
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if (err) {
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dev_err(&pdev->dev,
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"couldn't register CC700 device (err=%d)\n", err);
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goto exit_free_cc770;
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}
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return 0;
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exit_free_cc770:
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free_cc770dev(dev);
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exit_unmap_mem:
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iounmap(base);
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exit_release_mem:
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release_mem_region(mem->start, mem_size);
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return err;
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}
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static int __devexit cc770_platform_remove(struct platform_device *pdev)
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{
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struct net_device *dev = dev_get_drvdata(&pdev->dev);
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struct cc770_priv *priv = netdev_priv(dev);
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struct resource *mem;
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unregister_cc770dev(dev);
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iounmap(priv->reg_base);
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free_cc770dev(dev);
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mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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release_mem_region(mem->start, resource_size(mem));
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return 0;
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}
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static struct of_device_id __devinitdata cc770_platform_table[] = {
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{.compatible = "bosch,cc770"}, /* CC770 from Bosch */
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{.compatible = "intc,82527"}, /* AN82527 from Intel CP */
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{},
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};
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static struct platform_driver cc770_platform_driver = {
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.driver = {
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.name = DRV_NAME,
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.owner = THIS_MODULE,
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.of_match_table = cc770_platform_table,
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},
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.probe = cc770_platform_probe,
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.remove = __devexit_p(cc770_platform_remove),
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};
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module_platform_driver(cc770_platform_driver);
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