diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/cpufreq/tegra124-cpufreq.c | 59 |
1 files changed, 59 insertions, 0 deletions
diff --git a/drivers/cpufreq/tegra124-cpufreq.c b/drivers/cpufreq/tegra124-cpufreq.c index 4f0c637b3b49..7a1ea6fdcab6 100644 --- a/drivers/cpufreq/tegra124-cpufreq.c +++ b/drivers/cpufreq/tegra124-cpufreq.c @@ -6,6 +6,7 @@ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/clk.h> +#include <linux/cpufreq.h> #include <linux/err.h> #include <linux/init.h> #include <linux/kernel.h> @@ -128,8 +129,66 @@ out_put_np: return ret; } +static int __maybe_unused tegra124_cpufreq_suspend(struct device *dev) +{ + struct tegra124_cpufreq_priv *priv = dev_get_drvdata(dev); + int err; + + /* + * PLLP rate 408Mhz is below the CPU Fmax at Vmin and is safe to + * use during suspend and resume. So, switch the CPU clock source + * to PLLP and disable DFLL. + */ + err = clk_set_parent(priv->cpu_clk, priv->pllp_clk); + if (err < 0) { + dev_err(dev, "failed to reparent to PLLP: %d\n", err); + return err; + } + + clk_disable_unprepare(priv->dfll_clk); + + return 0; +} + +static int __maybe_unused tegra124_cpufreq_resume(struct device *dev) +{ + struct tegra124_cpufreq_priv *priv = dev_get_drvdata(dev); + int err; + + /* + * Warmboot code powers up the CPU with PLLP clock source. + * Enable DFLL clock and switch CPU clock source back to DFLL. + */ + err = clk_prepare_enable(priv->dfll_clk); + if (err < 0) { + dev_err(dev, "failed to enable DFLL clock for CPU: %d\n", err); + goto disable_cpufreq; + } + + err = clk_set_parent(priv->cpu_clk, priv->dfll_clk); + if (err < 0) { + dev_err(dev, "failed to reparent to DFLL clock: %d\n", err); + goto disable_dfll; + } + + return 0; + +disable_dfll: + clk_disable_unprepare(priv->dfll_clk); +disable_cpufreq: + disable_cpufreq(); + + return err; +} + +static const struct dev_pm_ops tegra124_cpufreq_pm_ops = { + SET_SYSTEM_SLEEP_PM_OPS(tegra124_cpufreq_suspend, + tegra124_cpufreq_resume) +}; + static struct platform_driver tegra124_cpufreq_platdrv = { .driver.name = "cpufreq-tegra124", + .driver.pm = &tegra124_cpufreq_pm_ops, .probe = tegra124_cpufreq_probe, }; |