diff options
Diffstat (limited to 'drivers/net/can')
| -rw-r--r-- | drivers/net/can/mscan/mpc52xx_can.c | 45 |
1 files changed, 16 insertions, 29 deletions
diff --git a/drivers/net/can/mscan/mpc52xx_can.c b/drivers/net/can/mscan/mpc52xx_can.c index 34ae2baec5d1..a915959b6b36 100644 --- a/drivers/net/can/mscan/mpc52xx_can.c +++ b/drivers/net/can/mscan/mpc52xx_can.c @@ -38,28 +38,37 @@ static struct of_device_id mpc52xx_cdm_ids[] __devinitdata = { { .compatible = "fsl,mpc5200-cdm", }, - { .compatible = "fsl,mpc5200b-cdm", }, {} }; /* - * Get the frequency of the external oscillator clock connected - * to the SYS_XTAL_IN pin, or return 0 if it cannot be determined. + * 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_xtal_freq(struct of_device *of) + +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; - /* - * Determine SYS_XTAL_IN frequency from the clock domain settings - */ + 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"); @@ -80,28 +89,6 @@ static unsigned int __devinit mpc52xx_can_xtal_freq(struct of_device *of) return freq; } -/* - * 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; - - pvr = mfspr(SPRN_PVR); - - if (clock_src == MSCAN_CLKSRC_BUS || pvr == 0x80822011) - return mpc5xxx_get_bus_frequency(of->node); - - return mpc52xx_can_xtal_freq(of); -} - static int __devinit mpc5xxx_can_probe(struct of_device *ofdev, const struct of_device_id *id) { |