diff options
Diffstat (limited to 'drivers/net/can/mscan/mpc5xxx_can.c')
| -rw-r--r-- | drivers/net/can/mscan/mpc5xxx_can.c | 259 |
1 files changed, 259 insertions, 0 deletions
diff --git a/drivers/net/can/mscan/mpc5xxx_can.c b/drivers/net/can/mscan/mpc5xxx_can.c new file mode 100644 index 0000000..1de6f63 --- /dev/null +++ b/drivers/net/can/mscan/mpc5xxx_can.c @@ -0,0 +1,259 @@ +/* + * 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(®s->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"); |
