diff options
Diffstat (limited to 'drivers/net/can/mscan/mpc5xxx_can.c')
-rw-r--r-- | drivers/net/can/mscan/mpc5xxx_can.c | 246 |
1 files changed, 204 insertions, 42 deletions
diff --git a/drivers/net/can/mscan/mpc5xxx_can.c b/drivers/net/can/mscan/mpc5xxx_can.c index 1de6f6349b16..f73487f723b8 100644 --- a/drivers/net/can/mscan/mpc5xxx_can.c +++ b/drivers/net/can/mscan/mpc5xxx_can.c @@ -29,6 +29,7 @@ #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> @@ -36,22 +37,21 @@ #define DRV_NAME "mpc5xxx_can" -static struct of_device_id mpc52xx_cdm_ids[] __devinitdata = { +struct mpc5xxx_can_data { + unsigned int type; + u32 (*get_clock)(struct of_device *ofdev, const char *clock_name, + int *mscan_clksrc); +}; + +#ifdef CONFIG_PPC_MPC5200 +static struct of_device_id __devinitdata mpc52xx_cdm_ids[] = { { .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) +static u32 __devinit mpc52xx_can_get_clock(struct of_device *ofdev, + const char *clock_name, + int *mscan_clksrc) { unsigned int pvr; struct mpc52xx_cdm __iomem *cdm; @@ -61,11 +61,24 @@ static unsigned int __devinit mpc52xx_can_clock_freq(struct of_device *of, pvr = mfspr(SPRN_PVR); - freq = mpc5xxx_get_bus_frequency(of->node); + /* + * 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->node); if (!freq) return 0; - if (clock_src == MSCAN_CLKSRC_BUS || pvr == 0x80822011) + if (*mscan_clksrc == MSCAN_CLKSRC_BUS || pvr == 0x80822011) return freq; /* Determine SYS_XTAL_IN frequency from the clock domain settings */ @@ -75,7 +88,6 @@ static unsigned int __devinit mpc52xx_can_clock_freq(struct of_device *of, return 0; } cdm = of_iomap(np_cdm, 0); - of_node_put(np_cdm); if (in_8(&cdm->ipb_clk_sel) & 0x1) freq *= 2; @@ -84,26 +96,174 @@ static unsigned int __devinit mpc52xx_can_clock_freq(struct of_device *of, freq *= (val & (1 << 5)) ? 8 : 4; freq /= (val & (1 << 6)) ? 12 : 16; + of_node_put(np_cdm); iounmap(cdm); return freq; } +#else /* !CONFIG_PPC_MPC5200 */ +static u32 __devinit mpc52xx_can_get_clock(struct of_device *ofdev, + const char *clock_name, + int *mscan_clksrc) +{ + return 0; +} +#endif /* CONFIG_PPC_MPC5200 */ + +#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 of_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 -ENODEV; + } + clockctl = of_iomap(np_clock, 0); + if (!clockctl) { + dev_err(&ofdev->dev, "couldn't map clock registers\n"); + return 0; + } + + /* Determine the MSCAN device index from the physical address */ + pval = of_get_property(ofdev->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->node); + } else { + *mscan_clksrc = MSCAN_CLKSRC_BUS; + + pval = of_get_property(ofdev->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: + of_node_put(np_clock); + iounmap(clockctl); + + return freq; +} +#else /* !CONFIG_PPC_MPC512x */ +static u32 __devinit mpc512x_can_get_clock(struct of_device *ofdev, + const char *clock_name, + int *mscan_clksrc) +{ + return 0; +} +#endif /* CONFIG_PPC_MPC512x */ static int __devinit mpc5xxx_can_probe(struct of_device *ofdev, const struct of_device_id *id) { + struct mpc5xxx_can_data *data = (struct mpc5xxx_can_data *)id->data; 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; + const char *clock_name = NULL; + int irq, mscan_clksrc = 0; + int err = -ENOMEM; - base = of_iomap(ofdev->node, 0); + base = of_iomap(np, 0); if (!base) { dev_err(&ofdev->dev, "couldn't ioremap\n"); - err = -ENOMEM; - goto exit_release_mem; + return err; } irq = irq_of_parse_and_map(np, 0); @@ -114,37 +274,27 @@ static int __devinit mpc5xxx_can_probe(struct of_device *ofdev, } dev = alloc_mscandev(); - if (!dev) { - err = -ENOMEM; + if (!dev) 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); + 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 frequency\n"); - err = -ENODEV; + 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, clock_src); + err = register_mscandev(dev, mscan_clksrc); if (err) { dev_err(&ofdev->dev, "registering %s failed (err=%d)\n", DRV_NAME, err); @@ -164,7 +314,7 @@ exit_dispose_irq: irq_dispose_mapping(irq); exit_unmap_mem: iounmap(base); -exit_release_mem: + return err; } @@ -225,8 +375,20 @@ static int mpc5xxx_can_resume(struct of_device *ofdev) } #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"}, + { .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, }, {}, }; @@ -255,5 +417,5 @@ static void __exit mpc5xxx_can_exit(void) module_exit(mpc5xxx_can_exit); MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>"); -MODULE_DESCRIPTION("Freescale MPC5200 CAN driver"); +MODULE_DESCRIPTION("Freescale MPC5xxx CAN driver"); MODULE_LICENSE("GPL v2"); |