diff options
Diffstat (limited to 'drivers/mfd')
| -rw-r--r-- | drivers/mfd/sm501.c | 33 |
1 files changed, 31 insertions, 2 deletions
diff --git a/drivers/mfd/sm501.c b/drivers/mfd/sm501.c index 3a0ecfc404e9..e14d70e07418 100644 --- a/drivers/mfd/sm501.c +++ b/drivers/mfd/sm501.c @@ -855,6 +855,24 @@ static void sm501_init_regs(struct sm501_devdata *sm, dev_info(sm->dev, "setting MCLK to %ld\n", init->mclk); sm501_set_clock(sm->dev, SM501_CLOCK_MCLK, init->mclk); } + +} + +/* Check the PLL sources for the M1CLK and M1XCLK + * + * If the M1CLK and M1XCLKs are not sourced from the same PLL, then + * there is a risk (see errata AB-5) that the SM501 will cease proper + * function. If this happens, then it is likely the SM501 will + * hang the system. +*/ + +static int sm501_check_clocks(struct sm501_devdata *sm) +{ + unsigned long pwrmode = readl(sm->regs + SM501_CURRENT_CLOCK); + unsigned long msrc = (pwrmode & SM501_POWERMODE_M_SRC); + unsigned long m1src = (pwrmode & SM501_POWERMODE_M1_SRC); + + return ((msrc == 0 && m1src != 0) || (msrc != 0 && m1src == 0)); } static unsigned int sm501_mem_local[] = { @@ -911,6 +929,13 @@ static int sm501_init_dev(struct sm501_devdata *sm) } } + ret = sm501_check_clocks(sm); + if (ret) { + dev_err(sm->dev, "M1X and M clocks sourced from different " + "PLLs\n"); + return -EINVAL; + } + /* always create a framebuffer */ sm501_register_display(sm, &mem_avail); @@ -1048,8 +1073,12 @@ static struct sm501_initdata sm501_pci_initdata = { }, .devices = SM501_USE_ALL, - .mclk = 100 * MHZ, - .m1xclk = 160 * MHZ, + + /* Errata AB-3 says that 72MHz is the fastest available + * for 33MHZ PCI with proper bus-mastering operation */ + + .mclk = 72 * MHZ, + .m1xclk = 144 * MHZ, }; static struct sm501_platdata_fbsub sm501_pdata_fbsub = { |