diff options
Diffstat (limited to 'drivers/soc/tegra/regulators-tegra30.c')
| -rw-r--r-- | drivers/soc/tegra/regulators-tegra30.c | 18 |
1 files changed, 17 insertions, 1 deletions
diff --git a/drivers/soc/tegra/regulators-tegra30.c b/drivers/soc/tegra/regulators-tegra30.c index 18fe53d0a870..e74bbc9c7859 100644 --- a/drivers/soc/tegra/regulators-tegra30.c +++ b/drivers/soc/tegra/regulators-tegra30.c @@ -18,6 +18,7 @@ #include <linux/regulator/machine.h> #include <soc/tegra/fuse.h> +#include <soc/tegra/pmc.h> struct tegra_regulator_coupler { struct regulator_coupler coupler; @@ -43,6 +44,21 @@ static int tegra30_core_limit(struct tegra_regulator_coupler *tegra, int core_cur_uV; int err; + /* + * Tegra30 SoC has critical DVFS-capable devices that are + * permanently-active or active at a boot time, like EMC + * (DRAM controller) or Display controller for example. + * + * The voltage of a CORE SoC power domain shall not be dropped below + * a minimum level, which is determined by device's clock rate. + * This means that we can't fully allow CORE voltage scaling until + * the state of all DVFS-critical CORE devices is synced. + */ + if (tegra_pmc_core_domain_state_synced() && !tegra->sys_reboot_mode) { + pr_info_once("voltage state synced\n"); + return 0; + } + if (tegra->core_min_uV > 0) return tegra->core_min_uV; @@ -63,7 +79,7 @@ static int tegra30_core_limit(struct tegra_regulator_coupler *tegra, */ tegra->core_min_uV = core_max_uV; - pr_info("core minimum voltage limited to %duV\n", tegra->core_min_uV); + pr_info("core voltage initialized to %duV\n", tegra->core_min_uV); return tegra->core_min_uV; } |