can: sja1000: generic OF platform bus driver

Memory mapped SJA1000 CAN controller from NXP (formerly Philips)

Required properties:

- compatible : should be "nxp,sja1000".

- reg : should specify the chip select, address offset and size required

	to map the registers of the SJA1000. The size is usually 0x80.

- interrupts: property with a value describing the interrupt source

	(number and sensitivity) required for the SJA1000.

Optional properties:

- nxp,external-clock-frequency : Frequency of the external oscillator

	clock in Hz. Note that the internal clock frequency used by the

	SJA1000 is half of that value. If not specified, a default value

	of 16000000 (16 MHz) is used.

- nxp,tx-output-mode : operation mode of the TX output control logic:

	<0x0> : bi-phase output mode

	<0x1> : normal output mode (default)

	<0x2> : test output mode

	<0x3> : clock output mode

- nxp,tx-output-config : TX output pin configuration:

	<0x01> : TX0 invert

	<0x02> : TX0 pull-down (default)

	<0x04> : TX0 pull-up

	<0x06> : TX0 push-pull

	<0x08> : TX1 invert

	<0x10> : TX1 pull-down

	<0x20> : TX1 pull-up

	<0x30> : TX1 push-pull

- nxp,clock-out-frequency : clock frequency in Hz on the CLKOUT pin.

	If not specified or if the specified value is 0, the CLKOUT pin

	will be disabled.

- nxp,no-comparator-bypass : Allows to disable the CAN input comperator.

For futher information, please have a look to the SJA1000 data sheet.

Examples:

can@3,100 {

	compatible = "nxp,sja1000";

	reg = <3 0x100 0x80>;

	interrupts = <2 0>;

	interrupt-parent = <&mpic>;

	nxp,external-clock-frequency = <16000000>;

};

	  boards from Phytec (http://www.phytec.de) like the PCM027,

	  PCM038.

config CAN_SJA1000_OF_PLATFORM

	depends on CAN_SJA1000 && PPC_OF

	tristate "Generic OF Platform Bus based SJA1000 driver"

	---help---

	  This driver adds support for the SJA1000 chips connected to

	  the OpenFirmware "platform bus" found on embedded systems with

	  OpenFirmware bindings, e.g. if you have a PowerPC based system

	  you may want to enable this option.

config CAN_EMS_PCI

	tristate "EMS CPC-PCI and CPC-PCIe Card"

	depends on PCI && CAN_SJA1000

obj-$(CONFIG_CAN_SJA1000) += sja1000.o

obj-$(CONFIG_CAN_SJA1000_PLATFORM) += sja1000_platform.o

obj-$(CONFIG_CAN_SJA1000_OF_PLATFORM) += sja1000_of_platform.o

obj-$(CONFIG_CAN_EMS_PCI) += ems_pci.o

obj-$(CONFIG_CAN_KVASER_PCI) += kvaser_pci.o

/*

 * Driver for SJA1000 CAN controllers on the OpenFirmware platform bus

 *

 * Copyright (C) 2008-2009 Wolfgang Grandegger <wg@grandegger.com>

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the version 2 of the GNU General Public License

 * as published by the Free Software Foundation

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software Foundation,

 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

 */

/* This is a generic driver for SJA1000 chips on the OpenFirmware platform

 * bus found on embedded PowerPC systems. You need a SJA1000 CAN node

 * definition in your flattened device tree source (DTS) file similar to:

 *

 *   can@3,100 {

 *           compatible = "nxp,sja1000";

 *           reg = <3 0x100 0x80>;

 *           interrupts = <2 0>;

 *           interrupt-parent = <&mpic>;

 *           nxp,external-clock-frequency = <16000000>;

 *   };

 *

 * See "Documentation/powerpc/dts-bindings/can/sja1000.txt" for further

 * information.

 */

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/interrupt.h>

#include <linux/netdevice.h>

#include <linux/delay.h>

#include <linux/can.h>

#include <linux/can/dev.h>

#include <linux/of_platform.h>

#include <asm/prom.h>

#include "sja1000.h"

#define DRV_NAME "sja1000_of_platform"

MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");

MODULE_DESCRIPTION("Socket-CAN driver for SJA1000 on the OF platform bus");

MODULE_LICENSE("GPL v2");

#define SJA1000_OFP_CAN_CLOCK  (16000000 / 2)

#define SJA1000_OFP_OCR        OCR_TX0_PULLDOWN

#define SJA1000_OFP_CDR        (CDR_CBP | CDR_CLK_OFF)

static u8 sja1000_ofp_read_reg(const struct sja1000_priv *priv, int reg)

{

	return in_8(priv->reg_base + reg);

}

static void sja1000_ofp_write_reg(const struct sja1000_priv *priv,

				  int reg, u8 val)

{

	out_8(priv->reg_base + reg, val);

}

static int __devexit sja1000_ofp_remove(struct of_device *ofdev)

{

	struct net_device *dev = dev_get_drvdata(&ofdev->dev);

	struct sja1000_priv *priv = netdev_priv(dev);

	struct device_node *np = ofdev->node;

	struct resource res;

	dev_set_drvdata(&ofdev->dev, NULL);

	unregister_sja1000dev(dev);

	free_sja1000dev(dev);

	iounmap(priv->reg_base);

	irq_dispose_mapping(dev->irq);

	of_address_to_resource(np, 0, &res);

	release_mem_region(res.start, resource_size(&res));

	return 0;

}

static int __devinit sja1000_ofp_probe(struct of_device *ofdev,

				       const struct of_device_id *id)

{

	struct device_node *np = ofdev->node;

	struct net_device *dev;

	struct sja1000_priv *priv;

	struct resource res;

	const u32 *prop;

	int err, irq, res_size, prop_size;

	void __iomem *base;

	err = of_address_to_resource(np, 0, &res);

	if (err) {

		dev_err(&ofdev->dev, "invalid address\n");

		return err;

	}

	res_size = resource_size(&res);

	if (!request_mem_region(res.start, res_size, DRV_NAME)) {

		dev_err(&ofdev->dev, "couldn't request %#x..%#x\n",

			res.start, res.end);

		return -EBUSY;

	}

	base = ioremap_nocache(res.start, res_size);

	if (!base) {

		dev_err(&ofdev->dev, "couldn't ioremap %#x..%#x\n",

			res.start, res.end);

		err = -ENOMEM;

		goto exit_release_mem;

	}

	irq = irq_of_parse_and_map(np, 0);

	if (irq == NO_IRQ) {

		dev_err(&ofdev->dev, "no irq found\n");

		err = -ENODEV;

		goto exit_unmap_mem;

	}

	dev = alloc_sja1000dev(0);

	if (!dev) {

		err = -ENOMEM;

		goto exit_dispose_irq;

	}

	priv = netdev_priv(dev);

	priv->read_reg = sja1000_ofp_read_reg;

	priv->write_reg = sja1000_ofp_write_reg;

	prop = of_get_property(np, "nxp,external-clock-frequency", &prop_size);

	if (prop && (prop_size ==  sizeof(u32)))

		priv->can.clock.freq = *prop / 2;

	else

		priv->can.clock.freq = SJA1000_OFP_CAN_CLOCK; /* default */

	prop = of_get_property(np, "nxp,tx-output-mode", &prop_size);

	if (prop && (prop_size == sizeof(u32)))

		priv->ocr |= *prop & OCR_MODE_MASK;

	else

		priv->ocr |= OCR_MODE_NORMAL; /* default */

	prop = of_get_property(np, "nxp,tx-output-config", &prop_size);

	if (prop && (prop_size == sizeof(u32)))

		priv->ocr |= (*prop << OCR_TX_SHIFT) & OCR_TX_MASK;

	else

		priv->ocr |= OCR_TX0_PULLDOWN; /* default */

	prop = of_get_property(np, "nxp,clock-out-frequency", &prop_size);

	if (prop && (prop_size == sizeof(u32)) && *prop) {

		u32 divider = priv->can.clock.freq * 2 / *prop;

		if (divider > 1)

			priv->cdr |= divider / 2 - 1;

		else

			priv->cdr |= CDR_CLKOUT_MASK;

	} else {

		priv->cdr |= CDR_CLK_OFF; /* default */

	}

	prop = of_get_property(np, "nxp,no-comparator-bypass", NULL);

	if (!prop)

		priv->cdr |= CDR_CBP; /* default */

	priv->irq_flags = IRQF_SHARED;

	priv->reg_base = base;

	dev->irq = irq;

	dev_info(&ofdev->dev,

		 "reg_base=0x%p irq=%d clock=%d ocr=0x%02x cdr=0x%02x\n",

		 priv->reg_base, dev->irq, priv->can.clock.freq,

		 priv->ocr, priv->cdr);

	dev_set_drvdata(&ofdev->dev, dev);

	SET_NETDEV_DEV(dev, &ofdev->dev);

	err = register_sja1000dev(dev);

	if (err) {

		dev_err(&ofdev->dev, "registering %s failed (err=%d)\n",

			DRV_NAME, err);

		goto exit_free_sja1000;

	}

	return 0;

exit_free_sja1000:

	free_sja1000dev(dev);

exit_dispose_irq:

	irq_dispose_mapping(irq);

exit_unmap_mem:

	iounmap(base);

exit_release_mem:

	release_mem_region(res.start, res_size);

	return err;

}

static struct of_device_id __devinitdata sja1000_ofp_table[] = {

	{.compatible = "nxp,sja1000"},

	{},

};

static struct of_platform_driver sja1000_ofp_driver = {

	.owner = THIS_MODULE,

	.name = DRV_NAME,

	.probe = sja1000_ofp_probe,

	.remove = __devexit_p(sja1000_ofp_remove),

	.match_table = sja1000_ofp_table,

};

static int __init sja1000_ofp_init(void)

{

	return of_register_platform_driver(&sja1000_ofp_driver);

}

module_init(sja1000_ofp_init);

static void __exit sja1000_ofp_exit(void)

{

	return of_unregister_platform_driver(&sja1000_ofp_driver);

};

module_exit(sja1000_ofp_exit);

#define OCR_MODE_TEST     0x01

#define OCR_MODE_NORMAL   0x02

#define OCR_MODE_CLOCK    0x03

#define OCR_MODE_MASK     0x07

#define OCR_TX0_INVERT    0x04

#define OCR_TX0_PULLDOWN  0x08

#define OCR_TX0_PULLUP    0x10

#define OCR_TX1_PULLDOWN  0x40

#define OCR_TX1_PULLUP    0x80

#define OCR_TX1_PUSHPULL  0xc0

#define OCR_TX_MASK       0xfc

#define OCR_TX_SHIFT      2

struct sja1000_platform_data {

	u32 clock;	/* CAN bus oscillator frequency in Hz */