diff options
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm/mach-tegra/clock.c | 38 |
1 files changed, 36 insertions, 2 deletions
diff --git a/arch/arm/mach-tegra/clock.c b/arch/arm/mach-tegra/clock.c index cf8bc38925..3bb72331a4 100644 --- a/arch/arm/mach-tegra/clock.c +++ b/arch/arm/mach-tegra/clock.c @@ -311,9 +311,43 @@ unsigned long clock_get_periph_rate(enum periph_id periph_id, enum clock_id parent) { u32 *reg = get_periph_source_reg(periph_id); + unsigned parent_rate = pll_rate[parent]; + int div = (readl(reg) & OUT_CLK_DIVISOR_MASK) >> OUT_CLK_DIVISOR_SHIFT; + + switch (periph_id) { + case PERIPH_ID_UART1: + case PERIPH_ID_UART2: + case PERIPH_ID_UART3: + case PERIPH_ID_UART4: + case PERIPH_ID_UART5: +#ifdef CONFIG_TEGRA20 + /* There's no divider for these clocks in this SoC. */ + return parent_rate; +#else + /* + * This undoes the +2 in get_rate_from_divider() which I + * believe is incorrect. Ideally we would fix + * get_rate_from_divider(), but... Removing the +2 from + * get_rate_from_divider() would probably require remove the -2 + * from the tail of clk_get_divider() since I believe that's + * only there to invert get_rate_from_divider()'s +2. Observe + * how find_best_divider() uses those two functions together. + * However, doing so breaks other stuff, such as Seaboard's + * display, likely due to clock_set_pllout()'s call to + * clk_get_divider(). Attempting to fix that by making + * clock_set_pllout() subtract 2 from clk_get_divider()'s + * return value doesn't help. In summary this clock driver is + * quite broken but I'm afraid I have no idea how to fix it + * without completely replacing it. + */ + div -= 2; + break; +#endif + default: + break; + } - return get_rate_from_divider(pll_rate[parent], - (readl(reg) & OUT_CLK_DIVISOR_MASK) >> OUT_CLK_DIVISOR_SHIFT); + return get_rate_from_divider(parent_rate, div); } /** |