260 lines
6.7 KiB
C
260 lines
6.7 KiB
C
/*
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* CAN bus driver for the Freescale MPC5xxx embedded CPU.
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*
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* Copyright (C) 2004-2005 Andrey Volkov <avolkov@varma-el.com>,
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* Varma Electronics Oy
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* Copyright (C) 2008-2009 Wolfgang Grandegger <wg@grandegger.com>
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* Copyright (C) 2009 Wolfram Sang, Pengutronix <w.sang@pengutronix.de>
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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, but
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* 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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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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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/platform_device.h>
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#include <linux/netdevice.h>
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#include <linux/can.h>
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#include <linux/can/dev.h>
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#include <linux/of_platform.h>
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#include <sysdev/fsl_soc.h>
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#include <linux/io.h>
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#include <asm/mpc52xx.h>
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#include "mscan.h"
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#define DRV_NAME "mpc5xxx_can"
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static struct of_device_id mpc52xx_cdm_ids[] __devinitdata = {
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{ .compatible = "fsl,mpc5200-cdm", },
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{}
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};
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/*
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* Get frequency of the MSCAN clock source
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*
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* Either the oscillator clock (SYS_XTAL_IN) or the IP bus clock (IP_CLK)
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* can be selected. According to the MPC5200 user's manual, the oscillator
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* clock is the better choice as it has less jitter but due to a hardware
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* bug, it can not be selected for the old MPC5200 Rev. A chips.
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*/
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static unsigned int __devinit mpc52xx_can_clock_freq(struct of_device *of,
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int clock_src)
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{
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unsigned int pvr;
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struct mpc52xx_cdm __iomem *cdm;
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struct device_node *np_cdm;
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unsigned int freq;
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u32 val;
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pvr = mfspr(SPRN_PVR);
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freq = mpc5xxx_get_bus_frequency(of->node);
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if (!freq)
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return 0;
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if (clock_src == MSCAN_CLKSRC_BUS || pvr == 0x80822011)
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return freq;
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/* Determine SYS_XTAL_IN frequency from the clock domain settings */
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np_cdm = of_find_matching_node(NULL, mpc52xx_cdm_ids);
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if (!np_cdm) {
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dev_err(&of->dev, "can't get clock node!\n");
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return 0;
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}
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cdm = of_iomap(np_cdm, 0);
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of_node_put(np_cdm);
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if (in_8(&cdm->ipb_clk_sel) & 0x1)
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freq *= 2;
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val = in_be32(&cdm->rstcfg);
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freq *= (val & (1 << 5)) ? 8 : 4;
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freq /= (val & (1 << 6)) ? 12 : 16;
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iounmap(cdm);
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return freq;
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}
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static int __devinit mpc5xxx_can_probe(struct of_device *ofdev,
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const struct of_device_id *id)
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{
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struct device_node *np = ofdev->node;
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struct net_device *dev;
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struct mscan_priv *priv;
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void __iomem *base;
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const char *clk_src;
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int err, irq, clock_src;
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base = of_iomap(ofdev->node, 0);
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if (!base) {
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dev_err(&ofdev->dev, "couldn't ioremap\n");
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err = -ENOMEM;
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goto exit_release_mem;
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}
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irq = irq_of_parse_and_map(np, 0);
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if (!irq) {
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dev_err(&ofdev->dev, "no irq found\n");
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err = -ENODEV;
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goto exit_unmap_mem;
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}
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dev = alloc_mscandev();
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if (!dev) {
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err = -ENOMEM;
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goto exit_dispose_irq;
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}
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priv = netdev_priv(dev);
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priv->reg_base = base;
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dev->irq = irq;
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/*
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* Either the oscillator clock (SYS_XTAL_IN) or the IP bus clock
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* (IP_CLK) can be selected as MSCAN clock source. According to
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* the MPC5200 user's manual, the oscillator clock is the better
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* choice as it has less jitter. For this reason, it is selected
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* by default.
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*/
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clk_src = of_get_property(np, "fsl,mscan-clock-source", NULL);
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if (clk_src && strcmp(clk_src, "ip") == 0)
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clock_src = MSCAN_CLKSRC_BUS;
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else
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clock_src = MSCAN_CLKSRC_XTAL;
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priv->can.clock.freq = mpc52xx_can_clock_freq(ofdev, clock_src);
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if (!priv->can.clock.freq) {
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dev_err(&ofdev->dev, "couldn't get MSCAN clock frequency\n");
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err = -ENODEV;
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goto exit_free_mscan;
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}
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SET_NETDEV_DEV(dev, &ofdev->dev);
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err = register_mscandev(dev, clock_src);
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if (err) {
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dev_err(&ofdev->dev, "registering %s failed (err=%d)\n",
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DRV_NAME, err);
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goto exit_free_mscan;
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}
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dev_set_drvdata(&ofdev->dev, dev);
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dev_info(&ofdev->dev, "MSCAN at 0x%p, irq %d, clock %d Hz\n",
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priv->reg_base, dev->irq, priv->can.clock.freq);
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return 0;
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exit_free_mscan:
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free_candev(dev);
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exit_dispose_irq:
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irq_dispose_mapping(irq);
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exit_unmap_mem:
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iounmap(base);
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exit_release_mem:
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return err;
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}
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static int __devexit mpc5xxx_can_remove(struct of_device *ofdev)
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{
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struct net_device *dev = dev_get_drvdata(&ofdev->dev);
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struct mscan_priv *priv = netdev_priv(dev);
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dev_set_drvdata(&ofdev->dev, NULL);
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unregister_mscandev(dev);
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iounmap(priv->reg_base);
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irq_dispose_mapping(dev->irq);
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free_candev(dev);
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return 0;
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}
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#ifdef CONFIG_PM
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static struct mscan_regs saved_regs;
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static int mpc5xxx_can_suspend(struct of_device *ofdev, pm_message_t state)
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{
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struct net_device *dev = dev_get_drvdata(&ofdev->dev);
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struct mscan_priv *priv = netdev_priv(dev);
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struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
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_memcpy_fromio(&saved_regs, regs, sizeof(*regs));
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return 0;
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}
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static int mpc5xxx_can_resume(struct of_device *ofdev)
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{
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struct net_device *dev = dev_get_drvdata(&ofdev->dev);
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struct mscan_priv *priv = netdev_priv(dev);
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struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
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regs->canctl0 |= MSCAN_INITRQ;
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while (!(regs->canctl1 & MSCAN_INITAK))
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udelay(10);
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regs->canctl1 = saved_regs.canctl1;
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regs->canbtr0 = saved_regs.canbtr0;
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regs->canbtr1 = saved_regs.canbtr1;
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regs->canidac = saved_regs.canidac;
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/* restore masks, buffers etc. */
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_memcpy_toio(®s->canidar1_0, (void *)&saved_regs.canidar1_0,
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sizeof(*regs) - offsetof(struct mscan_regs, canidar1_0));
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regs->canctl0 &= ~MSCAN_INITRQ;
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regs->cantbsel = saved_regs.cantbsel;
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regs->canrier = saved_regs.canrier;
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regs->cantier = saved_regs.cantier;
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regs->canctl0 = saved_regs.canctl0;
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return 0;
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}
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#endif
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static struct of_device_id __devinitdata mpc5xxx_can_table[] = {
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{.compatible = "fsl,mpc5200-mscan"},
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{},
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};
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static struct of_platform_driver mpc5xxx_can_driver = {
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.owner = THIS_MODULE,
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.name = "mpc5xxx_can",
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.probe = mpc5xxx_can_probe,
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.remove = __devexit_p(mpc5xxx_can_remove),
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#ifdef CONFIG_PM
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.suspend = mpc5xxx_can_suspend,
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.resume = mpc5xxx_can_resume,
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#endif
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.match_table = mpc5xxx_can_table,
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};
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static int __init mpc5xxx_can_init(void)
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{
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return of_register_platform_driver(&mpc5xxx_can_driver);
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}
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module_init(mpc5xxx_can_init);
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static void __exit mpc5xxx_can_exit(void)
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{
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return of_unregister_platform_driver(&mpc5xxx_can_driver);
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};
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module_exit(mpc5xxx_can_exit);
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MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
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MODULE_DESCRIPTION("Freescale MPC5200 CAN driver");
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MODULE_LICENSE("GPL v2");
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