/* * 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(®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 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");