drivers/net/can/mscan/mpc5xxx_can.c - kernel/msm - Gitiles

 /*
  * CAN bus driver for the Freescale MPC5xxx embedded CPU.
  *
  * Copyright (C) 2004-2005 Andrey Volkov <avolkov@varma-el.com>,
  *                         Varma Electronics Oy
  * Copyright (C) 2008-2009 Wolfgang Grandegger <wg@grandegger.com>
  * Copyright (C) 2009 Wolfram Sang, Pengutronix <w.sang@pengutronix.de>
  *
  * 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
  */

 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/interrupt.h>
 #include <linux/platform_device.h>
 #include <linux/netdevice.h>
 #include <linux/can.h>
 #include <linux/can/dev.h>
 #include <linux/of_platform.h>
 #include <sysdev/fsl_soc.h>
 #include <linux/io.h>
 #include <asm/mpc52xx.h>

 #include "mscan.h"

 #define DRV_NAME "mpc5xxx_can"

 static struct of_device_id mpc52xx_cdm_ids[] __devinitdata = {
 	{ .compatible = "fsl,mpc5200-cdm", },
 	{}
 };

 /*
  * Get frequency of the MSCAN clock source
  *
  * Either the oscillator clock (SYS_XTAL_IN) or the IP bus clock (IP_CLK)
  * can be selected. According to the MPC5200 user's manual, the oscillator
  * clock is the better choice as it has less jitter but due to a hardware
  * bug, it can not be selected for the old MPC5200 Rev. A chips.
  */

 static unsigned int  __devinit mpc52xx_can_clock_freq(struct of_device *of,
 						      int clock_src)
 {
 	unsigned int pvr;
 	struct mpc52xx_cdm  __iomem *cdm;
 	struct device_node *np_cdm;
 	unsigned int freq;
 	u32 val;

 	pvr = mfspr(SPRN_PVR);

 	freq = mpc5xxx_get_bus_frequency(of->node);
 	if (!freq)
 		return 0;

 	if (clock_src == MSCAN_CLKSRC_BUS || pvr == 0x80822011)
 		return freq;

 	/* Determine SYS_XTAL_IN frequency from the clock domain settings */
 	np_cdm = of_find_matching_node(NULL, mpc52xx_cdm_ids);
 	if (!np_cdm) {
 		dev_err(&of->dev, "can't get clock node!\n");
 		return 0;
 	}
 	cdm = of_iomap(np_cdm, 0);
 	of_node_put(np_cdm);

 	if (in_8(&cdm->ipb_clk_sel) & 0x1)
 		freq *= 2;
 	val = in_be32(&cdm->rstcfg);

 	freq *= (val & (1 << 5)) ? 8 : 4;
 	freq /= (val & (1 << 6)) ? 12 : 16;

 	iounmap(cdm);

 	return freq;
 }

 static int __devinit mpc5xxx_can_probe(struct of_device *ofdev,
 				       const struct of_device_id *id)
 {
 	struct device_node *np = ofdev->node;
 	struct net_device *dev;
 	struct mscan_priv *priv;
 	void __iomem *base;
 	const char *clk_src;
 	int err, irq, clock_src;

 	base = of_iomap(ofdev->node, 0);
 	if (!base) {
 		dev_err(&ofdev->dev, "couldn't ioremap\n");
 		err = -ENOMEM;
 		goto exit_release_mem;
 	}

 	irq = irq_of_parse_and_map(np, 0);
 	if (!irq) {
 		dev_err(&ofdev->dev, "no irq found\n");
 		err = -ENODEV;
 		goto exit_unmap_mem;
 	}

 	dev = alloc_mscandev();
 	if (!dev) {
 		err = -ENOMEM;
 		goto exit_dispose_irq;
 	}

 	priv = netdev_priv(dev);
 	priv->reg_base = base;
 	dev->irq = irq;

 	/*
 	 * Either the oscillator clock (SYS_XTAL_IN) or the IP bus clock
 	 * (IP_CLK) can be selected as MSCAN clock source. According to
 	 * the MPC5200 user's manual, the oscillator clock is the better
 	 * choice as it has less jitter. For this reason, it is selected
 	 * by default.
 	 */
 	clk_src = of_get_property(np, "fsl,mscan-clock-source", NULL);
 	if (clk_src && strcmp(clk_src, "ip") == 0)
 		clock_src = MSCAN_CLKSRC_BUS;
 	else
 		clock_src = MSCAN_CLKSRC_XTAL;
 	priv->can.clock.freq = mpc52xx_can_clock_freq(ofdev, clock_src);
 	if (!priv->can.clock.freq) {
 		dev_err(&ofdev->dev, "couldn't get MSCAN clock frequency\n");
 		err = -ENODEV;
 		goto exit_free_mscan;
 	}

 	SET_NETDEV_DEV(dev, &ofdev->dev);

 	err = register_mscandev(dev, clock_src);
 	if (err) {
 		dev_err(&ofdev->dev, "registering %s failed (err=%d)\n",
 			DRV_NAME, err);
 		goto exit_free_mscan;
 	}

 	dev_set_drvdata(&ofdev->dev, dev);

 	dev_info(&ofdev->dev, "MSCAN at 0x%p, irq %d, clock %d Hz\n",
 		 priv->reg_base, dev->irq, priv->can.clock.freq);

 	return 0;

 exit_free_mscan:
 	free_candev(dev);
 exit_dispose_irq:
 	irq_dispose_mapping(irq);
 exit_unmap_mem:
 	iounmap(base);
 exit_release_mem:
 	return err;
 }

 static int __devexit mpc5xxx_can_remove(struct of_device *ofdev)
 {
 	struct net_device *dev = dev_get_drvdata(&ofdev->dev);
 	struct mscan_priv *priv = netdev_priv(dev);

 	dev_set_drvdata(&ofdev->dev, NULL);

 	unregister_mscandev(dev);
 	iounmap(priv->reg_base);
 	irq_dispose_mapping(dev->irq);
 	free_candev(dev);

 	return 0;
 }

 #ifdef CONFIG_PM
 static struct mscan_regs saved_regs;
 static int mpc5xxx_can_suspend(struct of_device *ofdev, pm_message_t state)
 {
 	struct net_device *dev = dev_get_drvdata(&ofdev->dev);
 	struct mscan_priv *priv = netdev_priv(dev);
 	struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;

 	_memcpy_fromio(&saved_regs, regs, sizeof(*regs));

 	return 0;
 }

 static int mpc5xxx_can_resume(struct of_device *ofdev)
 {
 	struct net_device *dev = dev_get_drvdata(&ofdev->dev);
 	struct mscan_priv *priv = netdev_priv(dev);
 	struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;

 	regs->canctl0 |= MSCAN_INITRQ;
 	while (!(regs->canctl1 & MSCAN_INITAK))
 		udelay(10);

 	regs->canctl1 = saved_regs.canctl1;
 	regs->canbtr0 = saved_regs.canbtr0;
 	regs->canbtr1 = saved_regs.canbtr1;
 	regs->canidac = saved_regs.canidac;

 	/* restore masks, buffers etc. */
 	_memcpy_toio(&regs->canidar1_0, (void *)&saved_regs.canidar1_0,
 		     sizeof(*regs) - offsetof(struct mscan_regs, canidar1_0));

 	regs->canctl0 &= ~MSCAN_INITRQ;
 	regs->cantbsel = saved_regs.cantbsel;
 	regs->canrier = saved_regs.canrier;
 	regs->cantier = saved_regs.cantier;
 	regs->canctl0 = saved_regs.canctl0;

 	return 0;
 }
 #endif

 static struct of_device_id __devinitdata mpc5xxx_can_table[] = {
 	{.compatible = "fsl,mpc5200-mscan"},
 	{},
 };

 static struct of_platform_driver mpc5xxx_can_driver = {
 	.owner = THIS_MODULE,
 	.name = "mpc5xxx_can",
 	.probe = mpc5xxx_can_probe,
 	.remove = __devexit_p(mpc5xxx_can_remove),
 #ifdef CONFIG_PM
 	.suspend = mpc5xxx_can_suspend,
 	.resume = mpc5xxx_can_resume,
 #endif
 	.match_table = mpc5xxx_can_table,
 };

 static int __init mpc5xxx_can_init(void)
 {
 	return of_register_platform_driver(&mpc5xxx_can_driver);
 }
 module_init(mpc5xxx_can_init);

 static void __exit mpc5xxx_can_exit(void)
 {
 	return of_unregister_platform_driver(&mpc5xxx_can_driver);
 };
 module_exit(mpc5xxx_can_exit);

 MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
 MODULE_DESCRIPTION("Freescale MPC5200 CAN driver");
 MODULE_LICENSE("GPL v2");
	/*
	* CAN bus driver for the Freescale MPC5xxx embedded CPU.
	*
	* Copyright (C) 2004-2005 Andrey Volkov <avolkov@varma-el.com>,
	* Varma Electronics Oy
	* Copyright (C) 2008-2009 Wolfgang Grandegger <wg@grandegger.com>
	* Copyright (C) 2009 Wolfram Sang, Pengutronix <w.sang@pengutronix.de>
	*
	* 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
	*/

	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/interrupt.h>
	#include <linux/platform_device.h>
	#include <linux/netdevice.h>
	#include <linux/can.h>
	#include <linux/can/dev.h>
	#include <linux/of_platform.h>
	#include <sysdev/fsl_soc.h>
	#include <linux/io.h>
	#include <asm/mpc52xx.h>

	#include "mscan.h"

	#define DRV_NAME "mpc5xxx_can"

	static struct of_device_id mpc52xx_cdm_ids[] __devinitdata = {
	{ .compatible = "fsl,mpc5200-cdm", },
	{}
	};

	/*
	* Get frequency of the MSCAN clock source
	*
	* Either the oscillator clock (SYS_XTAL_IN) or the IP bus clock (IP_CLK)
	* can be selected. According to the MPC5200 user's manual, the oscillator
	* clock is the better choice as it has less jitter but due to a hardware
	* bug, it can not be selected for the old MPC5200 Rev. A chips.
	*/

	static unsigned int __devinit mpc52xx_can_clock_freq(struct of_device *of,
	int clock_src)
	{
	unsigned int pvr;
	struct mpc52xx_cdm __iomem *cdm;
	struct device_node *np_cdm;
	unsigned int freq;
	u32 val;

	pvr = mfspr(SPRN_PVR);

	freq = mpc5xxx_get_bus_frequency(of->node);
	if (!freq)
	return 0;

	if (clock_src == MSCAN_CLKSRC_BUS \|\| pvr == 0x80822011)
	return freq;

	/* Determine SYS_XTAL_IN frequency from the clock domain settings */
	np_cdm = of_find_matching_node(NULL, mpc52xx_cdm_ids);
	if (!np_cdm) {
	dev_err(&of->dev, "can't get clock node!\n");
	return 0;
	}
	cdm = of_iomap(np_cdm, 0);
	of_node_put(np_cdm);

	if (in_8(&cdm->ipb_clk_sel) & 0x1)
	freq *= 2;
	val = in_be32(&cdm->rstcfg);

	freq *= (val & (1 << 5)) ? 8 : 4;
	freq /= (val & (1 << 6)) ? 12 : 16;

	iounmap(cdm);

	return freq;
	}

	static int __devinit mpc5xxx_can_probe(struct of_device *ofdev,
	const struct of_device_id *id)
	{
	struct device_node *np = ofdev->node;
	struct net_device *dev;
	struct mscan_priv *priv;
	void __iomem *base;
	const char *clk_src;
	int err, irq, clock_src;

	base = of_iomap(ofdev->node, 0);
	if (!base) {
	dev_err(&ofdev->dev, "couldn't ioremap\n");
	err = -ENOMEM;
	goto exit_release_mem;
	}

	irq = irq_of_parse_and_map(np, 0);
	if (!irq) {
	dev_err(&ofdev->dev, "no irq found\n");
	err = -ENODEV;
	goto exit_unmap_mem;
	}

	dev = alloc_mscandev();
	if (!dev) {
	err = -ENOMEM;
	goto exit_dispose_irq;
	}

	priv = netdev_priv(dev);
	priv->reg_base = base;
	dev->irq = irq;

	/*
	* Either the oscillator clock (SYS_XTAL_IN) or the IP bus clock
	* (IP_CLK) can be selected as MSCAN clock source. According to
	* the MPC5200 user's manual, the oscillator clock is the better
	* choice as it has less jitter. For this reason, it is selected
	* by default.
	*/
	clk_src = of_get_property(np, "fsl,mscan-clock-source", NULL);
	if (clk_src && strcmp(clk_src, "ip") == 0)
	clock_src = MSCAN_CLKSRC_BUS;
	else
	clock_src = MSCAN_CLKSRC_XTAL;
	priv->can.clock.freq = mpc52xx_can_clock_freq(ofdev, clock_src);
	if (!priv->can.clock.freq) {
	dev_err(&ofdev->dev, "couldn't get MSCAN clock frequency\n");
	err = -ENODEV;
	goto exit_free_mscan;
	}

	SET_NETDEV_DEV(dev, &ofdev->dev);

	err = register_mscandev(dev, clock_src);
	if (err) {
	dev_err(&ofdev->dev, "registering %s failed (err=%d)\n",
	DRV_NAME, err);
	goto exit_free_mscan;
	}

	dev_set_drvdata(&ofdev->dev, dev);

	dev_info(&ofdev->dev, "MSCAN at 0x%p, irq %d, clock %d Hz\n",
	priv->reg_base, dev->irq, priv->can.clock.freq);

	return 0;

	exit_free_mscan:
	free_candev(dev);
	exit_dispose_irq:
	irq_dispose_mapping(irq);
	exit_unmap_mem:
	iounmap(base);
	exit_release_mem:
	return err;
	}

	static int __devexit mpc5xxx_can_remove(struct of_device *ofdev)
	{
	struct net_device *dev = dev_get_drvdata(&ofdev->dev);
	struct mscan_priv *priv = netdev_priv(dev);

	dev_set_drvdata(&ofdev->dev, NULL);

	unregister_mscandev(dev);
	iounmap(priv->reg_base);
	irq_dispose_mapping(dev->irq);
	free_candev(dev);

	return 0;
	}

	#ifdef CONFIG_PM
	static struct mscan_regs saved_regs;
	static int mpc5xxx_can_suspend(struct of_device *ofdev, pm_message_t state)
	{
	struct net_device *dev = dev_get_drvdata(&ofdev->dev);
	struct mscan_priv *priv = netdev_priv(dev);
	struct mscan_regs regs = (struct mscan_regs )priv->reg_base;

	_memcpy_fromio(&saved_regs, regs, sizeof(*regs));

	return 0;
	}

	static int mpc5xxx_can_resume(struct of_device *ofdev)
	{
	struct net_device *dev = dev_get_drvdata(&ofdev->dev);
	struct mscan_priv *priv = netdev_priv(dev);
	struct mscan_regs regs = (struct mscan_regs )priv->reg_base;

	regs->canctl0 \|= MSCAN_INITRQ;
	while (!(regs->canctl1 & MSCAN_INITAK))
	udelay(10);

	regs->canctl1 = saved_regs.canctl1;
	regs->canbtr0 = saved_regs.canbtr0;
	regs->canbtr1 = saved_regs.canbtr1;
	regs->canidac = saved_regs.canidac;

	/* restore masks, buffers etc. */
	_memcpy_toio(&regs->canidar1_0, (void *)&saved_regs.canidar1_0,
	sizeof(*regs) - offsetof(struct mscan_regs, canidar1_0));

	regs->canctl0 &= ~MSCAN_INITRQ;
	regs->cantbsel = saved_regs.cantbsel;
	regs->canrier = saved_regs.canrier;
	regs->cantier = saved_regs.cantier;
	regs->canctl0 = saved_regs.canctl0;

	return 0;
	}
	#endif

	static struct of_device_id __devinitdata mpc5xxx_can_table[] = {
	{.compatible = "fsl,mpc5200-mscan"},
	{},
	};

	static struct of_platform_driver mpc5xxx_can_driver = {
	.owner = THIS_MODULE,
	.name = "mpc5xxx_can",
	.probe = mpc5xxx_can_probe,
	.remove = __devexit_p(mpc5xxx_can_remove),
	#ifdef CONFIG_PM
	.suspend = mpc5xxx_can_suspend,
	.resume = mpc5xxx_can_resume,
	#endif
	.match_table = mpc5xxx_can_table,
	};

	static int __init mpc5xxx_can_init(void)
	{
	return of_register_platform_driver(&mpc5xxx_can_driver);
	}
	module_init(mpc5xxx_can_init);

	static void __exit mpc5xxx_can_exit(void)
	{
	return of_unregister_platform_driver(&mpc5xxx_can_driver);
	};
	module_exit(mpc5xxx_can_exit);

	MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
	MODULE_DESCRIPTION("Freescale MPC5200 CAN driver");
	MODULE_LICENSE("GPL v2");