[PATCH v13 27/35] soc/tegra: regulators: Prepare for suspend

Dmitry Osipenko
2021-09-26T22:44:11Z

Depending on hardware version, Tegra SoC may require a higher voltages
during resume from system suspend, otherwise hardware will crash. Set
SoC voltages to a nominal levels during suspend.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
drivers/soc/tegra/regulators-tegra20.c | 99 ++++++++++++++++++++
drivers/soc/tegra/regulators-tegra30.c | 122 +++++++++++++++++++++++++
2 files changed, 221 insertions(+)

diff --git a/drivers/soc/tegra/regulators-tegra20.c b/drivers/soc/tegra/regulators-tegra20.c
index b8ce9fd0650d..6a2f90ab9d3e 100644
--- a/drivers/soc/tegra/regulators-tegra20.c
+++ b/drivers/soc/tegra/regulators-tegra20.c
@@ -16,7 +16,9 @@
#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 {
@@ -25,9 +27,12 @@ struct tegra_regulator_coupler {
struct regulator_dev *cpu_rdev;
struct regulator_dev *rtc_rdev;
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 *
@@ -105,6 +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,
@@ -144,6 +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;
@@ -279,6 +311,11 @@ static int tegra20_cpu_voltage_update(struct tegra_regulator_coupler *tegra,
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);
@@ -320,6 +357,7 @@ static int tegra20_regulator_balance_voltage(struct regulator_coupler *coupler,
}

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,
@@ -334,6 +372,63 @@ 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)
{
@@ -444,6 +539,7 @@ static struct tegra_regulator_coupler tegra20_coupler = {
.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)
@@ -456,6 +552,9 @@ static int __init tegra_regulator_coupler_init(void)
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);
diff --git a/drivers/soc/tegra/regulators-tegra30.c b/drivers/soc/tegra/regulators-tegra30.c
index e74bbc9c7859..8fd43c689134 100644
--- a/drivers/soc/tegra/regulators-tegra30.c
+++ b/drivers/soc/tegra/regulators-tegra30.c
@@ -16,6 +16,7 @@
#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>
@@ -25,9 +26,12 @@ struct tegra_regulator_coupler {
struct regulator_dev *core_rdev;
struct regulator_dev *cpu_rdev;
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 *
@@ -113,6 +117,52 @@ static int tegra30_core_cpu_limit(int cpu_uV)
return -EINVAL;
}

+static int tegra30_cpu_nominal_uV(void)
+{
+ switch (tegra_sku_info.cpu_speedo_id) {
+ case 10 ... 11:
+ return 850000;
+
+ case 9:
+ return 912000;
+
+ case 1 ... 3:
+ case 7 ... 8:
+ return 1050000;
+
+ default:
+ return 1125000;
+
+ case 4 ... 6:
+ case 12 ... 13:
+ return 1237000;
+ }
+}
+
+static int tegra30_core_nominal_uV(void)
+{
+ switch (tegra_sku_info.soc_speedo_id) {
+ case 0:
+ return 1200000;
+
+ case 1:
+ if (tegra_sku_info.cpu_speedo_id != 7 &&
+ tegra_sku_info.cpu_speedo_id != 8)
+ return 1200000;
+
+ fallthrough;
+
+ case 2:
+ if (tegra_sku_info.cpu_speedo_id != 13)
+ return 1300000;
+
+ return 1350000;
+
+ default:
+ return 1250000;
+ }
+}
+
static int tegra30_voltage_update(struct tegra_regulator_coupler *tegra,
struct regulator_dev *cpu_rdev,
struct regulator_dev *core_rdev)
@@ -168,6 +218,11 @@ static int tegra30_voltage_update(struct tegra_regulator_coupler *tegra,
if (err)
return err;

+ /* prepare voltage level for suspend */
+ if (tegra->sys_suspend_mode)
+ core_min_uV = clamp(tegra30_core_nominal_uV(),
+ core_min_uV, core_max_uV);
+
core_uV = regulator_get_voltage_rdev(core_rdev);
if (core_uV < 0)
return core_uV;
@@ -223,6 +278,11 @@ static int tegra30_voltage_update(struct tegra_regulator_coupler *tegra,
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(tegra30_cpu_nominal_uV(),
+ cpu_min_uV, cpu_max_uV);
+
if (core_min_limited_uV > core_uV) {
pr_err("core voltage constraint violated: %d %d %d\n",
core_uV, core_min_limited_uV, cpu_uV);
@@ -292,10 +352,68 @@ static int tegra30_regulator_balance_voltage(struct regulator_coupler *coupler,
}

tegra->sys_reboot_mode = READ_ONCE(tegra->sys_reboot_mode_req);
+ tegra->sys_suspend_mode = READ_ONCE(tegra->sys_suspend_mode_req);

return tegra30_voltage_update(tegra, cpu_rdev, core_rdev);
}

+static int tegra30_regulator_prepare_suspend(struct tegra_regulator_coupler *tegra,
+ bool sys_suspend_mode)
+{
+ int err;
+
+ if (!tegra->core_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 tegra30_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 = tegra30_regulator_prepare_suspend(tegra, true);
+ break;
+
+ case PM_POST_HIBERNATION:
+ case PM_POST_RESTORE:
+ case PM_POST_SUSPEND:
+ ret = tegra30_regulator_prepare_suspend(tegra, false);
+ break;
+ }
+
+ if (ret)
+ pr_err("failed to prepare regulators: %d\n", ret);
+
+ return notifier_from_errno(ret);
+}
+
static int tegra30_regulator_prepare_reboot(struct tegra_regulator_coupler *tegra,
bool sys_reboot_mode)
{
@@ -395,6 +513,7 @@ static struct tegra_regulator_coupler tegra30_coupler = {
.balance_voltage = tegra30_regulator_balance_voltage,
},
.reboot_notifier.notifier_call = tegra30_regulator_reboot,
+ .suspend_notifier.notifier_call = tegra30_regulator_suspend,
};

static int __init tegra_regulator_coupler_init(void)
@@ -407,6 +526,9 @@ static int __init tegra_regulator_coupler_init(void)
err = register_reboot_notifier(&tegra30_coupler.reboot_notifier);
WARN_ON(err);

+ err = register_pm_notifier(&tegra30_coupler.suspend_notifier);
+ WARN_ON(err);
+
return regulator_coupler_register(&tegra30_coupler.coupler);
}
arch_initcall(tegra_regulator_coupler_init);
--
2.32.0