Tegra had always been switching to intermediate frequency (pll_p_clk) since ever. CPUFreq core has better support for handling notifications for these frequencies and so we can adapt Tegra's driver to it.
Also do a WARN() if clk_set_parent() fails while moving back to pll_x as we should have atleast restored to earlier frequency on error. Signed-off-by: Viresh Kumar <[email protected]> --- drivers/cpufreq/tegra-cpufreq.c | 81 ++++++++++++++++++++++++----------------- 1 file changed, 47 insertions(+), 34 deletions(-) diff --git a/drivers/cpufreq/tegra-cpufreq.c b/drivers/cpufreq/tegra-cpufreq.c index 6e774c6..a64b970 100644 --- a/drivers/cpufreq/tegra-cpufreq.c +++ b/drivers/cpufreq/tegra-cpufreq.c @@ -46,7 +46,24 @@ static struct clk *pll_x_clk; static struct clk *pll_p_clk; static struct clk *emc_clk; -static int tegra_cpu_clk_set_rate(unsigned long rate) +static unsigned int +tegra_get_intermediate(struct cpufreq_policy *policy, unsigned int index) +{ + unsigned int ifreq = clk_get_rate(pll_p_clk) / 1000; + + /* + * Don't switch to intermediate freq if: + * - we are already at it, i.e. policy->cur == ifreq + * - index corresponds to ifreq + */ + if ((freq_table[index].frequency == ifreq) || (policy->cur == ifreq)) + return 0; + + return ifreq; +} + +static int +tegra_target_intermediate(struct cpufreq_policy *policy, unsigned int index) { int ret; @@ -57,28 +74,9 @@ static int tegra_cpu_clk_set_rate(unsigned long rate) clk_prepare_enable(pll_x_clk); ret = clk_set_parent(cpu_clk, pll_p_clk); - if (ret) { - pr_err("Failed to switch cpu to clock pll_p\n"); - goto out; - } - - if (rate == clk_get_rate(pll_p_clk)) - goto out; - - ret = clk_set_rate(pll_x_clk, rate); - if (ret) { - pr_err("Failed to change pll_x to %lu\n", rate); - goto out; - } - - ret = clk_set_parent(cpu_clk, pll_x_clk); - if (ret) { - pr_err("Failed to switch cpu to clock pll_x\n"); - goto out; - } + if (ret) + clk_disable_unprepare(pll_x_clk); -out: - clk_disable_unprepare(pll_x_clk); return ret; } @@ -98,10 +96,23 @@ static int tegra_target(struct cpufreq_policy *policy, unsigned int index) else clk_set_rate(emc_clk, 100000000); /* emc 50Mhz */ - ret = tegra_cpu_clk_set_rate(rate * 1000); + /* target freq == pll_p */ + if (rate * 1000 == clk_get_rate(pll_p_clk)) { + ret = tegra_target_intermediate(policy, index); + goto disable_pll_x; + } + + ret = clk_set_rate(pll_x_clk, rate * 1000); + /* Restore to earlier frequency on error, i.e. pll_x */ if (ret) - pr_err("cpu-tegra: Failed to set cpu frequency to %lu kHz\n", - rate); + pr_err("Failed to change pll_x to %lu\n", rate); + + ret = clk_set_parent(cpu_clk, pll_x_clk); + /* This shouldn't fail while changing or restoring */ + WARN_ON(ret); + +disable_pll_x: + clk_disable_unprepare(pll_x_clk); return ret; } @@ -137,16 +148,18 @@ static int tegra_cpu_exit(struct cpufreq_policy *policy) } static struct cpufreq_driver tegra_cpufreq_driver = { - .flags = CPUFREQ_NEED_INITIAL_FREQ_CHECK, - .verify = cpufreq_generic_frequency_table_verify, - .target_index = tegra_target, - .get = cpufreq_generic_get, - .init = tegra_cpu_init, - .exit = tegra_cpu_exit, - .name = "tegra", - .attr = cpufreq_generic_attr, + .flags = CPUFREQ_NEED_INITIAL_FREQ_CHECK, + .verify = cpufreq_generic_frequency_table_verify, + .get_intermediate = tegra_get_intermediate, + .target_intermediate = tegra_target_intermediate, + .target_index = tegra_target, + .get = cpufreq_generic_get, + .init = tegra_cpu_init, + .exit = tegra_cpu_exit, + .name = "tegra", + .attr = cpufreq_generic_attr, #ifdef CONFIG_PM - .suspend = cpufreq_generic_suspend, + .suspend = cpufreq_generic_suspend, #endif }; -- 2.0.0.rc2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
