diff options
Diffstat (limited to 'drivers/soc/tegra/regulators-tegra20.c')
| -rw-r--r-- | drivers/soc/tegra/regulators-tegra20.c | 193 |
1 files changed, 191 insertions, 2 deletions
diff --git a/drivers/soc/tegra/regulators-tegra20.c b/drivers/soc/tegra/regulators-tegra20.c index 367a71a3cd10..6a2f90ab9d3e 100644 --- a/drivers/soc/tegra/regulators-tegra20.c +++ b/drivers/soc/tegra/regulators-tegra20.c @@ -12,16 +12,27 @@ #include <linux/init.h> #include <linux/kernel.h> #include <linux/of.h> +#include <linux/reboot.h> #include <linux/regulator/coupler.h> #include <linux/regulator/driver.h> #include <linux/regulator/machine.h> +#include <linux/suspend.h> + +#include <soc/tegra/fuse.h> +#include <soc/tegra/pmc.h> struct tegra_regulator_coupler { struct regulator_coupler coupler; struct regulator_dev *core_rdev; struct regulator_dev *cpu_rdev; struct regulator_dev *rtc_rdev; - int core_min_uV; + struct notifier_block reboot_notifier; + struct notifier_block suspend_notifier; + int core_min_uV, cpu_min_uV; + bool sys_reboot_mode_req; + bool sys_reboot_mode; + bool sys_suspend_mode_req; + bool sys_suspend_mode; }; static inline struct tegra_regulator_coupler * @@ -38,6 +49,21 @@ static int tegra20_core_limit(struct tegra_regulator_coupler *tegra, int core_cur_uV; int err; + /* + * Tegra20 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; @@ -58,7 +84,7 @@ static int tegra20_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; } @@ -84,6 +110,28 @@ static int tegra20_core_rtc_max_spread(struct regulator_dev *core_rdev, return 150000; } +static int tegra20_cpu_nominal_uV(void) +{ + switch (tegra_sku_info.soc_speedo_id) { + case 0: + return 1100000; + case 1: + return 1025000; + default: + return 1125000; + } +} + +static int tegra20_core_nominal_uV(void) +{ + switch (tegra_sku_info.soc_speedo_id) { + default: + return 1225000; + case 2: + return 1300000; + } +} + static int tegra20_core_rtc_update(struct tegra_regulator_coupler *tegra, struct regulator_dev *core_rdev, struct regulator_dev *rtc_rdev, @@ -123,6 +171,11 @@ static int tegra20_core_rtc_update(struct tegra_regulator_coupler *tegra, if (err) return err; + /* prepare voltage level for suspend */ + if (tegra->sys_suspend_mode) + core_min_uV = clamp(tegra20_core_nominal_uV(), + core_min_uV, core_max_uV); + core_uV = regulator_get_voltage_rdev(core_rdev); if (core_uV < 0) return core_uV; @@ -242,6 +295,10 @@ static int tegra20_cpu_voltage_update(struct tegra_regulator_coupler *tegra, if (cpu_uV < 0) return cpu_uV; + /* store boot voltage level */ + if (!tegra->cpu_min_uV) + tegra->cpu_min_uV = cpu_uV; + /* * CPU's regulator may not have any consumers, hence the voltage * must not be changed in that case because CPU simply won't @@ -250,6 +307,15 @@ static int tegra20_cpu_voltage_update(struct tegra_regulator_coupler *tegra, if (!cpu_min_uV_consumers) cpu_min_uV = cpu_uV; + /* restore boot voltage level */ + if (tegra->sys_reboot_mode) + cpu_min_uV = max(cpu_min_uV, tegra->cpu_min_uV); + + /* prepare voltage level for suspend */ + if (tegra->sys_suspend_mode) + cpu_min_uV = clamp(tegra20_cpu_nominal_uV(), + cpu_min_uV, cpu_max_uV); + if (cpu_min_uV > cpu_uV) { err = tegra20_core_rtc_update(tegra, core_rdev, rtc_rdev, cpu_uV, cpu_min_uV); @@ -290,6 +356,9 @@ static int tegra20_regulator_balance_voltage(struct regulator_coupler *coupler, return -EINVAL; } + tegra->sys_reboot_mode = READ_ONCE(tegra->sys_reboot_mode_req); + tegra->sys_suspend_mode = READ_ONCE(tegra->sys_suspend_mode_req); + if (rdev == cpu_rdev) return tegra20_cpu_voltage_update(tegra, cpu_rdev, core_rdev, rtc_rdev); @@ -303,6 +372,108 @@ static int tegra20_regulator_balance_voltage(struct regulator_coupler *coupler, return -EPERM; } +static int tegra20_regulator_prepare_suspend(struct tegra_regulator_coupler *tegra, + bool sys_suspend_mode) +{ + int err; + + if (!tegra->core_rdev || !tegra->rtc_rdev || !tegra->cpu_rdev) + return 0; + + /* + * All power domains are enabled early during resume from suspend + * by GENPD core. Domains like VENC may require a higher voltage + * when enabled during resume from suspend. This also prepares + * hardware for resuming from LP0. + */ + + WRITE_ONCE(tegra->sys_suspend_mode_req, sys_suspend_mode); + + err = regulator_sync_voltage_rdev(tegra->cpu_rdev); + if (err) + return err; + + err = regulator_sync_voltage_rdev(tegra->core_rdev); + if (err) + return err; + + return 0; +} + +static int tegra20_regulator_suspend(struct notifier_block *notifier, + unsigned long mode, void *arg) +{ + struct tegra_regulator_coupler *tegra; + int ret = 0; + + tegra = container_of(notifier, struct tegra_regulator_coupler, + suspend_notifier); + + switch (mode) { + case PM_HIBERNATION_PREPARE: + case PM_RESTORE_PREPARE: + case PM_SUSPEND_PREPARE: + ret = tegra20_regulator_prepare_suspend(tegra, true); + break; + + case PM_POST_HIBERNATION: + case PM_POST_RESTORE: + case PM_POST_SUSPEND: + ret = tegra20_regulator_prepare_suspend(tegra, false); + break; + } + + if (ret) + pr_err("failed to prepare regulators: %d\n", ret); + + return notifier_from_errno(ret); +} + +static int tegra20_regulator_prepare_reboot(struct tegra_regulator_coupler *tegra, + bool sys_reboot_mode) +{ + int err; + + if (!tegra->core_rdev || !tegra->rtc_rdev || !tegra->cpu_rdev) + return 0; + + WRITE_ONCE(tegra->sys_reboot_mode_req, true); + + /* + * Some devices use CPU soft-reboot method and in this case we + * should ensure that voltages are sane for the reboot by restoring + * the minimum boot levels. + */ + err = regulator_sync_voltage_rdev(tegra->cpu_rdev); + if (err) + return err; + + err = regulator_sync_voltage_rdev(tegra->core_rdev); + if (err) + return err; + + WRITE_ONCE(tegra->sys_reboot_mode_req, sys_reboot_mode); + + return 0; +} + +static int tegra20_regulator_reboot(struct notifier_block *notifier, + unsigned long event, void *cmd) +{ + struct tegra_regulator_coupler *tegra; + int ret; + + if (event != SYS_RESTART) + return NOTIFY_DONE; + + tegra = container_of(notifier, struct tegra_regulator_coupler, + reboot_notifier); + + ret = tegra20_regulator_prepare_reboot(tegra, true); + + return notifier_from_errno(ret); +} + static int tegra20_regulator_attach(struct regulator_coupler *coupler, struct regulator_dev *rdev) { @@ -335,6 +506,14 @@ static int tegra20_regulator_detach(struct regulator_coupler *coupler, { struct tegra_regulator_coupler *tegra = to_tegra_coupler(coupler); + /* + * We don't expect regulators to be decoupled during reboot, + * this may race with the reboot handler and shouldn't ever + * happen in practice. + */ + if (WARN_ON_ONCE(system_state > SYSTEM_RUNNING)) + return -EPERM; + if (tegra->core_rdev == rdev) { tegra->core_rdev = NULL; return 0; @@ -359,13 +538,23 @@ static struct tegra_regulator_coupler tegra20_coupler = { .detach_regulator = tegra20_regulator_detach, .balance_voltage = tegra20_regulator_balance_voltage, }, + .reboot_notifier.notifier_call = tegra20_regulator_reboot, + .suspend_notifier.notifier_call = tegra20_regulator_suspend, }; static int __init tegra_regulator_coupler_init(void) { + int err; + if (!of_machine_is_compatible("nvidia,tegra20")) return 0; + err = register_reboot_notifier(&tegra20_coupler.reboot_notifier); + WARN_ON(err); + + err = register_pm_notifier(&tegra20_coupler.suspend_notifier); + WARN_ON(err); + return regulator_coupler_register(&tegra20_coupler.coupler); } arch_initcall(tegra_regulator_coupler_init); |