drivers/net/can/mscan/mpc5xxx_can.c - maze/linux - Git at Google

 /*
  * 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/dev.h>
 #include <linux/of_platform.h>
 #include <sysdev/fsl_soc.h>
 #include <linux/clk.h>
 #include <linux/io.h>
 #include <asm/mpc52xx.h>

 #include "mscan.h"

 #define DRV_NAME "mpc5xxx_can"

 struct mpc5xxx_can_data {
 	unsigned int type;
 	u32 (*get_clock)(struct platform_device *ofdev, const char *clock_name,
 			 int *mscan_clksrc);
 };

 #ifdef CONFIG_PPC_MPC52xx
 static struct of_device_id __devinitdata mpc52xx_cdm_ids[] = {
 	{ .compatible = "fsl,mpc5200-cdm", },
 	{}
 };

 static u32 __devinit mpc52xx_can_get_clock(struct platform_device *ofdev,
 					   const char *clock_name,
 					   int *mscan_clksrc)
 {
 	unsigned int pvr;
 	struct mpc52xx_cdm  __iomem *cdm;
 	struct device_node *np_cdm;
 	unsigned int freq;
 	u32 val;

 	pvr = mfspr(SPRN_PVR);

 	/*
 	 * 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. Unfortunately, it can not be selected for the old
 	 * MPC5200 Rev. A chips due to a hardware bug (check errata).
 	 */
 	if (clock_name && strcmp(clock_name, "ip") == 0)
 		*mscan_clksrc = MSCAN_CLKSRC_BUS;
 	else
 		*mscan_clksrc = MSCAN_CLKSRC_XTAL;

 	freq = mpc5xxx_get_bus_frequency(ofdev->dev.of_node);
 	if (!freq)
 		return 0;

 	if (*mscan_clksrc == 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(&ofdev->dev, "can't get clock node!\n");
 		return 0;
 	}
 	cdm = of_iomap(np_cdm, 0);

 	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;

 	of_node_put(np_cdm);
 	iounmap(cdm);

 	return freq;
 }
 #else /* !CONFIG_PPC_MPC52xx */
 static u32 __devinit mpc52xx_can_get_clock(struct platform_device *ofdev,
 					   const char *clock_name,
 					   int *mscan_clksrc)
 {
 	return 0;
 }
 #endif /* CONFIG_PPC_MPC52xx */

 #ifdef CONFIG_PPC_MPC512x
 struct mpc512x_clockctl {
 	u32 spmr;		/* System PLL Mode Reg */
 	u32 sccr[2];		/* System Clk Ctrl Reg 1 & 2 */
 	u32 scfr1;		/* System Clk Freq Reg 1 */
 	u32 scfr2;		/* System Clk Freq Reg 2 */
 	u32 reserved;
 	u32 bcr;		/* Bread Crumb Reg */
 	u32 pccr[12];		/* PSC Clk Ctrl Reg 0-11 */
 	u32 spccr;		/* SPDIF Clk Ctrl Reg */
 	u32 cccr;		/* CFM Clk Ctrl Reg */
 	u32 dccr;		/* DIU Clk Cnfg Reg */
 	u32 mccr[4];		/* MSCAN Clk Ctrl Reg 1-3 */
 };

 static struct of_device_id __devinitdata mpc512x_clock_ids[] = {
 	{ .compatible = "fsl,mpc5121-clock", },
 	{}
 };

 static u32 __devinit mpc512x_can_get_clock(struct platform_device *ofdev,
 					   const char *clock_name,
 					   int *mscan_clksrc)
 {
 	struct mpc512x_clockctl __iomem *clockctl;
 	struct device_node *np_clock;
 	struct clk *sys_clk, *ref_clk;
 	int plen, clockidx, clocksrc = -1;
 	u32 sys_freq, val, clockdiv = 1, freq = 0;
 	const u32 *pval;

 	np_clock = of_find_matching_node(NULL, mpc512x_clock_ids);
 	if (!np_clock) {
 		dev_err(&ofdev->dev, "couldn't find clock node\n");
 		return 0;
 	}
 	clockctl = of_iomap(np_clock, 0);
 	if (!clockctl) {
 		dev_err(&ofdev->dev, "couldn't map clock registers\n");
 		goto exit_put;
 	}

 	/* Determine the MSCAN device index from the physical address */
 	pval = of_get_property(ofdev->dev.of_node, "reg", &plen);
 	BUG_ON(!pval || plen < sizeof(*pval));
 	clockidx = (*pval & 0x80) ? 1 : 0;
 	if (*pval & 0x2000)
 		clockidx += 2;

 	/*
 	 * Clock source and divider selection: 3 different clock sources
 	 * can be selected: "ip", "ref" or "sys". For the latter two, a
 	 * clock divider can be defined as well. If the clock source is
 	 * not specified by the device tree, we first try to find an
 	 * optimal CAN source clock based on the system clock. If that
 	 * is not posslible, the reference clock will be used.
 	 */
 	if (clock_name && !strcmp(clock_name, "ip")) {
 		*mscan_clksrc = MSCAN_CLKSRC_IPS;
 		freq = mpc5xxx_get_bus_frequency(ofdev->dev.of_node);
 	} else {
 		*mscan_clksrc = MSCAN_CLKSRC_BUS;

 		pval = of_get_property(ofdev->dev.of_node,
 				       "fsl,mscan-clock-divider", &plen);
 		if (pval && plen == sizeof(*pval))
 			clockdiv = *pval;
 		if (!clockdiv)
 			clockdiv = 1;

 		if (!clock_name || !strcmp(clock_name, "sys")) {
 			sys_clk = clk_get(&ofdev->dev, "sys_clk");
 			if (!sys_clk) {
 				dev_err(&ofdev->dev, "couldn't get sys_clk\n");
 				goto exit_unmap;
 			}
 			/* Get and round up/down sys clock rate */
 			sys_freq = 1000000 *
 				((clk_get_rate(sys_clk) + 499999) / 1000000);

 			if (!clock_name) {
 				/* A multiple of 16 MHz would be optimal */
 				if ((sys_freq % 16000000) == 0) {
 					clocksrc = 0;
 					clockdiv = sys_freq / 16000000;
 					freq = sys_freq / clockdiv;
 				}
 			} else {
 				clocksrc = 0;
 				freq = sys_freq / clockdiv;
 			}
 		}

 		if (clocksrc < 0) {
 			ref_clk = clk_get(&ofdev->dev, "ref_clk");
 			if (!ref_clk) {
 				dev_err(&ofdev->dev, "couldn't get ref_clk\n");
 				goto exit_unmap;
 			}
 			clocksrc = 1;
 			freq = clk_get_rate(ref_clk) / clockdiv;
 		}
 	}

 	/* Disable clock */
 	out_be32(&clockctl->mccr[clockidx], 0x0);
 	if (clocksrc >= 0) {
 		/* Set source and divider */
 		val = (clocksrc << 14) | ((clockdiv - 1) << 17);
 		out_be32(&clockctl->mccr[clockidx], val);
 		/* Enable clock */
 		out_be32(&clockctl->mccr[clockidx], val | 0x10000);
 	}

 	/* Enable MSCAN clock domain */
 	val = in_be32(&clockctl->sccr[1]);
 	if (!(val & (1 << 25)))
 		out_be32(&clockctl->sccr[1], val | (1 << 25));

 	dev_dbg(&ofdev->dev, "using '%s' with frequency divider %d\n",
 		*mscan_clksrc == MSCAN_CLKSRC_IPS ? "ips_clk" :
 		clocksrc == 1 ? "ref_clk" : "sys_clk", clockdiv);

 exit_unmap:
 	iounmap(clockctl);
 exit_put:
 	of_node_put(np_clock);
 	return freq;
 }
 #else /* !CONFIG_PPC_MPC512x */
 static u32 __devinit mpc512x_can_get_clock(struct platform_device *ofdev,
 					   const char *clock_name,
 					   int *mscan_clksrc)
 {
 	return 0;
 }
 #endif /* CONFIG_PPC_MPC512x */

 static struct of_device_id mpc5xxx_can_table[];
 static int __devinit mpc5xxx_can_probe(struct platform_device *ofdev)
 {
 	const struct of_device_id *match;
 	struct mpc5xxx_can_data *data;
 	struct device_node *np = ofdev->dev.of_node;
 	struct net_device *dev;
 	struct mscan_priv *priv;
 	void __iomem *base;
 	const char *clock_name = NULL;
 	int irq, mscan_clksrc = 0;
 	int err = -ENOMEM;

 	match = of_match_device(mpc5xxx_can_table, &ofdev->dev);
 	if (!match)
 		return -EINVAL;
 	data = match->data;

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

 	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)
 		goto exit_dispose_irq;

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

 	clock_name = of_get_property(np, "fsl,mscan-clock-source", NULL);

 	BUG_ON(!data);
 	priv->type = data->type;
 	priv->can.clock.freq = data->get_clock(ofdev, clock_name,
 					       &mscan_clksrc);
 	if (!priv->can.clock.freq) {
 		dev_err(&ofdev->dev, "couldn't get MSCAN clock properties\n");
 		goto exit_free_mscan;
 	}

 	SET_NETDEV_DEV(dev, &ofdev->dev);

 	err = register_mscandev(dev, mscan_clksrc);
 	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);

 	return err;
 }

 static int __devexit mpc5xxx_can_remove(struct platform_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 platform_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 platform_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 mpc5xxx_can_data __devinitdata mpc5200_can_data = {
 	.type = MSCAN_TYPE_MPC5200,
 	.get_clock = mpc52xx_can_get_clock,
 };

 static struct mpc5xxx_can_data __devinitdata mpc5121_can_data = {
 	.type = MSCAN_TYPE_MPC5121,
 	.get_clock = mpc512x_can_get_clock,
 };

 static struct of_device_id __devinitdata mpc5xxx_can_table[] = {
 	{ .compatible = "fsl,mpc5200-mscan", .data = &mpc5200_can_data, },
 	/* Note that only MPC5121 Rev. 2 (and later) is supported */
 	{ .compatible = "fsl,mpc5121-mscan", .data = &mpc5121_can_data, },
 	{},
 };

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

 module_platform_driver(mpc5xxx_can_driver);

 MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
 MODULE_DESCRIPTION("Freescale MPC5xxx 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/dev.h>
	#include <linux/of_platform.h>
	#include <sysdev/fsl_soc.h>
	#include <linux/clk.h>
	#include <linux/io.h>
	#include <asm/mpc52xx.h>

	#include "mscan.h"

	#define DRV_NAME "mpc5xxx_can"

	struct mpc5xxx_can_data {
	unsigned int type;
	u32 (get_clock)(struct platform_device ofdev, const char *clock_name,
	int *mscan_clksrc);
	};

	#ifdef CONFIG_PPC_MPC52xx
	static struct of_device_id __devinitdata mpc52xx_cdm_ids[] = {
	{ .compatible = "fsl,mpc5200-cdm", },
	{}
	};

	static u32 __devinit mpc52xx_can_get_clock(struct platform_device *ofdev,
	const char *clock_name,
	int *mscan_clksrc)
	{
	unsigned int pvr;
	struct mpc52xx_cdm __iomem *cdm;
	struct device_node *np_cdm;
	unsigned int freq;
	u32 val;

	pvr = mfspr(SPRN_PVR);

	/*
	* 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. Unfortunately, it can not be selected for the old
	* MPC5200 Rev. A chips due to a hardware bug (check errata).
	*/
	if (clock_name && strcmp(clock_name, "ip") == 0)
	*mscan_clksrc = MSCAN_CLKSRC_BUS;
	else
	*mscan_clksrc = MSCAN_CLKSRC_XTAL;

	freq = mpc5xxx_get_bus_frequency(ofdev->dev.of_node);
	if (!freq)
	return 0;

	if (*mscan_clksrc == 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(&ofdev->dev, "can't get clock node!\n");
	return 0;
	}
	cdm = of_iomap(np_cdm, 0);

	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;

	of_node_put(np_cdm);
	iounmap(cdm);

	return freq;
	}
	#else /* !CONFIG_PPC_MPC52xx */
	static u32 __devinit mpc52xx_can_get_clock(struct platform_device *ofdev,
	const char *clock_name,
	int *mscan_clksrc)
	{
	return 0;
	}
	#endif /* CONFIG_PPC_MPC52xx */

	#ifdef CONFIG_PPC_MPC512x
	struct mpc512x_clockctl {
	u32 spmr; /* System PLL Mode Reg */
	u32 sccr[2]; /* System Clk Ctrl Reg 1 & 2 */
	u32 scfr1; /* System Clk Freq Reg 1 */
	u32 scfr2; /* System Clk Freq Reg 2 */
	u32 reserved;
	u32 bcr; /* Bread Crumb Reg */
	u32 pccr[12]; /* PSC Clk Ctrl Reg 0-11 */
	u32 spccr; /* SPDIF Clk Ctrl Reg */
	u32 cccr; /* CFM Clk Ctrl Reg */
	u32 dccr; /* DIU Clk Cnfg Reg */
	u32 mccr[4]; /* MSCAN Clk Ctrl Reg 1-3 */
	};

	static struct of_device_id __devinitdata mpc512x_clock_ids[] = {
	{ .compatible = "fsl,mpc5121-clock", },
	{}
	};

	static u32 __devinit mpc512x_can_get_clock(struct platform_device *ofdev,
	const char *clock_name,
	int *mscan_clksrc)
	{
	struct mpc512x_clockctl __iomem *clockctl;
	struct device_node *np_clock;
	struct clk sys_clk, ref_clk;
	int plen, clockidx, clocksrc = -1;
	u32 sys_freq, val, clockdiv = 1, freq = 0;
	const u32 *pval;

	np_clock = of_find_matching_node(NULL, mpc512x_clock_ids);
	if (!np_clock) {
	dev_err(&ofdev->dev, "couldn't find clock node\n");
	return 0;
	}
	clockctl = of_iomap(np_clock, 0);
	if (!clockctl) {
	dev_err(&ofdev->dev, "couldn't map clock registers\n");
	goto exit_put;
	}

	/* Determine the MSCAN device index from the physical address */
	pval = of_get_property(ofdev->dev.of_node, "reg", &plen);
	BUG_ON(!pval \|\| plen < sizeof(*pval));
	clockidx = (*pval & 0x80) ? 1 : 0;
	if (*pval & 0x2000)
	clockidx += 2;

	/*
	* Clock source and divider selection: 3 different clock sources
	* can be selected: "ip", "ref" or "sys". For the latter two, a
	* clock divider can be defined as well. If the clock source is
	* not specified by the device tree, we first try to find an
	* optimal CAN source clock based on the system clock. If that
	* is not posslible, the reference clock will be used.
	*/
	if (clock_name && !strcmp(clock_name, "ip")) {
	*mscan_clksrc = MSCAN_CLKSRC_IPS;
	freq = mpc5xxx_get_bus_frequency(ofdev->dev.of_node);
	} else {
	*mscan_clksrc = MSCAN_CLKSRC_BUS;

	pval = of_get_property(ofdev->dev.of_node,
	"fsl,mscan-clock-divider", &plen);
	if (pval && plen == sizeof(*pval))
	clockdiv = *pval;
	if (!clockdiv)
	clockdiv = 1;

	if (!clock_name \|\| !strcmp(clock_name, "sys")) {
	sys_clk = clk_get(&ofdev->dev, "sys_clk");
	if (!sys_clk) {
	dev_err(&ofdev->dev, "couldn't get sys_clk\n");
	goto exit_unmap;
	}
	/* Get and round up/down sys clock rate */
	sys_freq = 1000000 *
	((clk_get_rate(sys_clk) + 499999) / 1000000);

	if (!clock_name) {
	/* A multiple of 16 MHz would be optimal */
	if ((sys_freq % 16000000) == 0) {
	clocksrc = 0;
	clockdiv = sys_freq / 16000000;
	freq = sys_freq / clockdiv;
	}
	} else {
	clocksrc = 0;
	freq = sys_freq / clockdiv;
	}
	}

	if (clocksrc < 0) {
	ref_clk = clk_get(&ofdev->dev, "ref_clk");
	if (!ref_clk) {
	dev_err(&ofdev->dev, "couldn't get ref_clk\n");
	goto exit_unmap;
	}
	clocksrc = 1;
	freq = clk_get_rate(ref_clk) / clockdiv;
	}
	}

	/* Disable clock */
	out_be32(&clockctl->mccr[clockidx], 0x0);
	if (clocksrc >= 0) {
	/* Set source and divider */
	val = (clocksrc << 14) \| ((clockdiv - 1) << 17);
	out_be32(&clockctl->mccr[clockidx], val);
	/* Enable clock */
	out_be32(&clockctl->mccr[clockidx], val \| 0x10000);
	}

	/* Enable MSCAN clock domain */
	val = in_be32(&clockctl->sccr[1]);
	if (!(val & (1 << 25)))
	out_be32(&clockctl->sccr[1], val \| (1 << 25));

	dev_dbg(&ofdev->dev, "using '%s' with frequency divider %d\n",
	*mscan_clksrc == MSCAN_CLKSRC_IPS ? "ips_clk" :
	clocksrc == 1 ? "ref_clk" : "sys_clk", clockdiv);

	exit_unmap:
	iounmap(clockctl);
	exit_put:
	of_node_put(np_clock);
	return freq;
	}
	#else /* !CONFIG_PPC_MPC512x */
	static u32 __devinit mpc512x_can_get_clock(struct platform_device *ofdev,
	const char *clock_name,
	int *mscan_clksrc)
	{
	return 0;
	}
	#endif /* CONFIG_PPC_MPC512x */

	static struct of_device_id mpc5xxx_can_table[];
	static int __devinit mpc5xxx_can_probe(struct platform_device *ofdev)
	{
	const struct of_device_id *match;
	struct mpc5xxx_can_data *data;
	struct device_node *np = ofdev->dev.of_node;
	struct net_device *dev;
	struct mscan_priv *priv;
	void __iomem *base;
	const char *clock_name = NULL;
	int irq, mscan_clksrc = 0;
	int err = -ENOMEM;

	match = of_match_device(mpc5xxx_can_table, &ofdev->dev);
	if (!match)
	return -EINVAL;
	data = match->data;

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

	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)
	goto exit_dispose_irq;

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

	clock_name = of_get_property(np, "fsl,mscan-clock-source", NULL);

	BUG_ON(!data);
	priv->type = data->type;
	priv->can.clock.freq = data->get_clock(ofdev, clock_name,
	&mscan_clksrc);
	if (!priv->can.clock.freq) {
	dev_err(&ofdev->dev, "couldn't get MSCAN clock properties\n");
	goto exit_free_mscan;
	}

	SET_NETDEV_DEV(dev, &ofdev->dev);

	err = register_mscandev(dev, mscan_clksrc);
	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);

	return err;
	}

	static int __devexit mpc5xxx_can_remove(struct platform_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 platform_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 platform_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 mpc5xxx_can_data __devinitdata mpc5200_can_data = {
	.type = MSCAN_TYPE_MPC5200,
	.get_clock = mpc52xx_can_get_clock,
	};

	static struct mpc5xxx_can_data __devinitdata mpc5121_can_data = {
	.type = MSCAN_TYPE_MPC5121,
	.get_clock = mpc512x_can_get_clock,
	};

	static struct of_device_id __devinitdata mpc5xxx_can_table[] = {
	{ .compatible = "fsl,mpc5200-mscan", .data = &mpc5200_can_data, },
	/* Note that only MPC5121 Rev. 2 (and later) is supported */
	{ .compatible = "fsl,mpc5121-mscan", .data = &mpc5121_can_data, },
	{},
	};

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

	module_platform_driver(mpc5xxx_can_driver);

	MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
	MODULE_DESCRIPTION("Freescale MPC5xxx CAN driver");
	MODULE_LICENSE("GPL v2");