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soc/tegra: regulators: Bump voltages on system reboot
Ensure that SoC voltages are at a level suitable for a system reboot. This is important for some devices that use CPU reset method for the rebooting. SoC CPU and core voltages now are be restored to a level that is suitable for rebooting. This patch fixes hang on reboot on Asus Transformer TF101, it was also reported as fixing some of reboot issues on Toshiba AC100. Reported-by: Nikola Milosavljević <mnidza@outlook.com> Tested-by: Nikola Milosavljević <mnidza@outlook.com> # TF101 Signed-off-by: Dmitry Osipenko <digetx@gmail.com> Signed-off-by: Thierry Reding <treding@nvidia.com>
This commit is contained in:
Dmitry Osipenko
Thierry Reding
parent
241ed23c4d
commit
03978d42ed
@ -12,6 +12,7 @@
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/of.h>
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#include <linux/reboot.h>
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#include <linux/regulator/coupler.h>
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#include <linux/regulator/driver.h>
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#include <linux/regulator/machine.h>
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@ -21,7 +22,10 @@ struct tegra_regulator_coupler {
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struct regulator_dev *core_rdev;
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struct regulator_dev *cpu_rdev;
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struct regulator_dev *rtc_rdev;
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int core_min_uV;
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struct notifier_block reboot_notifier;
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int core_min_uV, cpu_min_uV;
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bool sys_reboot_mode_req;
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bool sys_reboot_mode;
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};
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static inline struct tegra_regulator_coupler *
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@ -242,6 +246,10 @@ static int tegra20_cpu_voltage_update(struct tegra_regulator_coupler *tegra,
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if (cpu_uV < 0)
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return cpu_uV;
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/* store boot voltage level */
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if (!tegra->cpu_min_uV)
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tegra->cpu_min_uV = cpu_uV;
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/*
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* CPU's regulator may not have any consumers, hence the voltage
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* must not be changed in that case because CPU simply won't
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@ -250,6 +258,10 @@ static int tegra20_cpu_voltage_update(struct tegra_regulator_coupler *tegra,
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if (!cpu_min_uV_consumers)
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cpu_min_uV = cpu_uV;
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/* restore boot voltage level */
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if (tegra->sys_reboot_mode)
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cpu_min_uV = max(cpu_min_uV, tegra->cpu_min_uV);
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if (cpu_min_uV > cpu_uV) {
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err = tegra20_core_rtc_update(tegra, core_rdev, rtc_rdev,
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cpu_uV, cpu_min_uV);
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@ -290,6 +302,8 @@ static int tegra20_regulator_balance_voltage(struct regulator_coupler *coupler,
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return -EINVAL;
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}
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tegra->sys_reboot_mode = READ_ONCE(tegra->sys_reboot_mode_req);
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if (rdev == cpu_rdev)
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return tegra20_cpu_voltage_update(tegra, cpu_rdev,
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core_rdev, rtc_rdev);
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@ -303,6 +317,51 @@ static int tegra20_regulator_balance_voltage(struct regulator_coupler *coupler,
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return -EPERM;
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}
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static int tegra20_regulator_prepare_reboot(struct tegra_regulator_coupler *tegra,
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bool sys_reboot_mode)
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{
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int err;
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if (!tegra->core_rdev || !tegra->rtc_rdev || !tegra->cpu_rdev)
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return 0;
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WRITE_ONCE(tegra->sys_reboot_mode_req, true);
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/*
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* Some devices use CPU soft-reboot method and in this case we
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* should ensure that voltages are sane for the reboot by restoring
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* the minimum boot levels.
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*/
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err = regulator_sync_voltage_rdev(tegra->cpu_rdev);
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if (err)
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return err;
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err = regulator_sync_voltage_rdev(tegra->core_rdev);
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if (err)
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return err;
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WRITE_ONCE(tegra->sys_reboot_mode_req, sys_reboot_mode);
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return 0;
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}
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static int tegra20_regulator_reboot(struct notifier_block *notifier,
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unsigned long event, void *cmd)
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{
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struct tegra_regulator_coupler *tegra;
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int ret;
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if (event != SYS_RESTART)
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return NOTIFY_DONE;
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tegra = container_of(notifier, struct tegra_regulator_coupler,
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reboot_notifier);
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ret = tegra20_regulator_prepare_reboot(tegra, true);
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return notifier_from_errno(ret);
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}
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static int tegra20_regulator_attach(struct regulator_coupler *coupler,
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struct regulator_dev *rdev)
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{
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@ -335,6 +394,14 @@ static int tegra20_regulator_detach(struct regulator_coupler *coupler,
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{
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struct tegra_regulator_coupler *tegra = to_tegra_coupler(coupler);
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/*
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* We don't expect regulators to be decoupled during reboot,
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* this may race with the reboot handler and shouldn't ever
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* happen in practice.
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*/
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if (WARN_ON_ONCE(system_state > SYSTEM_RUNNING))
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return -EPERM;
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if (tegra->core_rdev == rdev) {
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tegra->core_rdev = NULL;
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return 0;
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@ -359,13 +426,19 @@ static struct tegra_regulator_coupler tegra20_coupler = {
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.detach_regulator = tegra20_regulator_detach,
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.balance_voltage = tegra20_regulator_balance_voltage,
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},
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.reboot_notifier.notifier_call = tegra20_regulator_reboot,
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};
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static int __init tegra_regulator_coupler_init(void)
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{
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int err;
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if (!of_machine_is_compatible("nvidia,tegra20"))
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return 0;
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err = register_reboot_notifier(&tegra20_coupler.reboot_notifier);
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WARN_ON(err);
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return regulator_coupler_register(&tegra20_coupler.coupler);
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}
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arch_initcall(tegra_regulator_coupler_init);
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@ -12,6 +12,7 @@
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/of.h>
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#include <linux/reboot.h>
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#include <linux/regulator/coupler.h>
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#include <linux/regulator/driver.h>
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#include <linux/regulator/machine.h>
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@ -22,7 +23,10 @@ struct tegra_regulator_coupler {
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struct regulator_coupler coupler;
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struct regulator_dev *core_rdev;
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struct regulator_dev *cpu_rdev;
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int core_min_uV;
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struct notifier_block reboot_notifier;
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int core_min_uV, cpu_min_uV;
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bool sys_reboot_mode_req;
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bool sys_reboot_mode;
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};
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static inline struct tegra_regulator_coupler *
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@ -172,6 +176,10 @@ static int tegra30_voltage_update(struct tegra_regulator_coupler *tegra,
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if (cpu_uV < 0)
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return cpu_uV;
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/* store boot voltage level */
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if (!tegra->cpu_min_uV)
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tegra->cpu_min_uV = cpu_uV;
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/*
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* CPU's regulator may not have any consumers, hence the voltage
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* must not be changed in that case because CPU simply won't
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@ -195,6 +203,10 @@ static int tegra30_voltage_update(struct tegra_regulator_coupler *tegra,
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if (err)
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return err;
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/* restore boot voltage level */
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if (tegra->sys_reboot_mode)
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cpu_min_uV = max(cpu_min_uV, tegra->cpu_min_uV);
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if (core_min_limited_uV > core_uV) {
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pr_err("core voltage constraint violated: %d %d %d\n",
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core_uV, core_min_limited_uV, cpu_uV);
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@ -263,9 +275,56 @@ static int tegra30_regulator_balance_voltage(struct regulator_coupler *coupler,
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return -EINVAL;
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}
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tegra->sys_reboot_mode = READ_ONCE(tegra->sys_reboot_mode_req);
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return tegra30_voltage_update(tegra, cpu_rdev, core_rdev);
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}
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static int tegra30_regulator_prepare_reboot(struct tegra_regulator_coupler *tegra,
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bool sys_reboot_mode)
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{
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int err;
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if (!tegra->core_rdev || !tegra->cpu_rdev)
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return 0;
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WRITE_ONCE(tegra->sys_reboot_mode_req, true);
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/*
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* Some devices use CPU soft-reboot method and in this case we
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* should ensure that voltages are sane for the reboot by restoring
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* the minimum boot levels.
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*/
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err = regulator_sync_voltage_rdev(tegra->cpu_rdev);
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if (err)
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return err;
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err = regulator_sync_voltage_rdev(tegra->core_rdev);
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if (err)
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return err;
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WRITE_ONCE(tegra->sys_reboot_mode_req, sys_reboot_mode);
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return 0;
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}
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static int tegra30_regulator_reboot(struct notifier_block *notifier,
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unsigned long event, void *cmd)
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{
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struct tegra_regulator_coupler *tegra;
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int ret;
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if (event != SYS_RESTART)
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return NOTIFY_DONE;
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tegra = container_of(notifier, struct tegra_regulator_coupler,
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reboot_notifier);
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ret = tegra30_regulator_prepare_reboot(tegra, true);
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return notifier_from_errno(ret);
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}
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static int tegra30_regulator_attach(struct regulator_coupler *coupler,
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struct regulator_dev *rdev)
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{
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@ -292,6 +351,14 @@ static int tegra30_regulator_detach(struct regulator_coupler *coupler,
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{
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struct tegra_regulator_coupler *tegra = to_tegra_coupler(coupler);
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/*
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* We don't expect regulators to be decoupled during reboot,
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* this may race with the reboot handler and shouldn't ever
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* happen in practice.
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*/
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if (WARN_ON_ONCE(system_state > SYSTEM_RUNNING))
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return -EPERM;
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if (tegra->core_rdev == rdev) {
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tegra->core_rdev = NULL;
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return 0;
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@ -311,13 +378,19 @@ static struct tegra_regulator_coupler tegra30_coupler = {
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.detach_regulator = tegra30_regulator_detach,
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.balance_voltage = tegra30_regulator_balance_voltage,
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},
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.reboot_notifier.notifier_call = tegra30_regulator_reboot,
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};
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static int __init tegra_regulator_coupler_init(void)
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{
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int err;
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if (!of_machine_is_compatible("nvidia,tegra30"))
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return 0;
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err = register_reboot_notifier(&tegra30_coupler.reboot_notifier);
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WARN_ON(err);
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return regulator_coupler_register(&tegra30_coupler.coupler);
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}
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arch_initcall(tegra_regulator_coupler_init);
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