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authorOlof Johansson <olof@lixom.net>2021-06-15 08:35:27 -0700
committerOlof Johansson <olof@lixom.net>2021-06-15 08:35:29 -0700
commit777cf27fb22669a50196c023676ec60de36c91b7 (patch)
treef24be3ef67e74539dc04e3666ab26ed4cb8bdb6d /drivers/soc
parent805be5c9e6ca6d9bb7c6d620f8b84b44ed3fcc3c (diff)
parente2d0ee225e49a5553986f3138dd2803852a31fd5 (diff)
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Merge tag 'tegra-for-5.14-soc' of git://git.kernel.org/pub/scm/linux/kernel/git/tegra/linux into arm/soc
soc/tegra: Changes for v5.14-rc1 These changes implement the core power domain for the PMC, and fix a couple of minor issues as well as add stubs to help some drivers be compile tested more easily. * tag 'tegra-for-5.14-soc' of git://git.kernel.org/pub/scm/linux/kernel/git/tegra/linux: soc/tegra: fuse: Fix Tegra234-only builds soc/tegra: fuse: Don't return -ENOMEM when allocate lookups failed soc/tegra: regulators: Support core domain state syncing soc/tegra: pmc: Add driver state syncing soc/tegra: pmc: Add core power domain soc/tegra: fuse: Add stubs needed for compile-testing soc/tegra: Add devm_tegra_core_dev_init_opp_table() soc/tegra: Add stub for soc_is_tegra() soc/tegra: regulators: Bump voltages on system reboot regulator: core: Add regulator_sync_voltage_rdev() Link: https://lore.kernel.org/r/20210611164437.3568059-2-thierry.reding@gmail.com Signed-off-by: Olof Johansson <olof@lixom.net>
Diffstat (limited to 'drivers/soc')
-rw-r--r--drivers/soc/tegra/Kconfig2
-rw-r--r--drivers/soc/tegra/common.c97
-rw-r--r--drivers/soc/tegra/fuse/fuse-tegra.c6
-rw-r--r--drivers/soc/tegra/fuse/fuse-tegra30.c3
-rw-r--r--drivers/soc/tegra/pmc.c144
-rw-r--r--drivers/soc/tegra/regulators-tegra20.c94
-rw-r--r--drivers/soc/tegra/regulators-tegra30.c93
7 files changed, 430 insertions, 9 deletions
diff --git a/drivers/soc/tegra/Kconfig b/drivers/soc/tegra/Kconfig
index 976dee036470..20ace654553a 100644
--- a/drivers/soc/tegra/Kconfig
+++ b/drivers/soc/tegra/Kconfig
@@ -144,6 +144,8 @@ config SOC_TEGRA_FLOWCTRL
config SOC_TEGRA_PMC
bool
select GENERIC_PINCONF
+ select PM_OPP
+ select PM_GENERIC_DOMAINS
config SOC_TEGRA_POWERGATE_BPMP
def_bool y
diff --git a/drivers/soc/tegra/common.c b/drivers/soc/tegra/common.c
index 3dc54f59cafe..cd33e99249c3 100644
--- a/drivers/soc/tegra/common.c
+++ b/drivers/soc/tegra/common.c
@@ -3,9 +3,16 @@
* Copyright (C) 2014 NVIDIA CORPORATION. All rights reserved.
*/
+#define dev_fmt(fmt) "tegra-soc: " fmt
+
+#include <linux/clk.h>
+#include <linux/device.h>
+#include <linux/export.h>
#include <linux/of.h>
+#include <linux/pm_opp.h>
#include <soc/tegra/common.h>
+#include <soc/tegra/fuse.h>
static const struct of_device_id tegra_machine_match[] = {
{ .compatible = "nvidia,tegra20", },
@@ -31,3 +38,93 @@ bool soc_is_tegra(void)
return match != NULL;
}
+
+static int tegra_core_dev_init_opp_state(struct device *dev)
+{
+ unsigned long rate;
+ struct clk *clk;
+ int err;
+
+ clk = devm_clk_get(dev, NULL);
+ if (IS_ERR(clk)) {
+ dev_err(dev, "failed to get clk: %pe\n", clk);
+ return PTR_ERR(clk);
+ }
+
+ rate = clk_get_rate(clk);
+ if (!rate) {
+ dev_err(dev, "failed to get clk rate\n");
+ return -EINVAL;
+ }
+
+ /* first dummy rate-setting initializes voltage vote */
+ err = dev_pm_opp_set_rate(dev, rate);
+ if (err) {
+ dev_err(dev, "failed to initialize OPP clock: %d\n", err);
+ return err;
+ }
+
+ return 0;
+}
+
+/**
+ * devm_tegra_core_dev_init_opp_table() - initialize OPP table
+ * @dev: device for which OPP table is initialized
+ * @params: pointer to the OPP table configuration
+ *
+ * This function will initialize OPP table and sync OPP state of a Tegra SoC
+ * core device.
+ *
+ * Return: 0 on success or errorno.
+ */
+int devm_tegra_core_dev_init_opp_table(struct device *dev,
+ struct tegra_core_opp_params *params)
+{
+ u32 hw_version;
+ int err;
+
+ err = devm_pm_opp_set_clkname(dev, NULL);
+ if (err) {
+ dev_err(dev, "failed to set OPP clk: %d\n", err);
+ return err;
+ }
+
+ /* Tegra114+ doesn't support OPP yet */
+ if (!of_machine_is_compatible("nvidia,tegra20") &&
+ !of_machine_is_compatible("nvidia,tegra30"))
+ return -ENODEV;
+
+ if (of_machine_is_compatible("nvidia,tegra20"))
+ hw_version = BIT(tegra_sku_info.soc_process_id);
+ else
+ hw_version = BIT(tegra_sku_info.soc_speedo_id);
+
+ err = devm_pm_opp_set_supported_hw(dev, &hw_version, 1);
+ if (err) {
+ dev_err(dev, "failed to set OPP supported HW: %d\n", err);
+ return err;
+ }
+
+ /*
+ * Older device-trees have an empty OPP table, we will get
+ * -ENODEV from devm_pm_opp_of_add_table() in this case.
+ */
+ err = devm_pm_opp_of_add_table(dev);
+ if (err) {
+ if (err == -ENODEV)
+ dev_err_once(dev, "OPP table not found, please update device-tree\n");
+ else
+ dev_err(dev, "failed to add OPP table: %d\n", err);
+
+ return err;
+ }
+
+ if (params->init_state) {
+ err = tegra_core_dev_init_opp_state(dev);
+ if (err)
+ return err;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(devm_tegra_core_dev_init_opp_table);
diff --git a/drivers/soc/tegra/fuse/fuse-tegra.c b/drivers/soc/tegra/fuse/fuse-tegra.c
index 94b60a692b51..3d9da3d359da 100644
--- a/drivers/soc/tegra/fuse/fuse-tegra.c
+++ b/drivers/soc/tegra/fuse/fuse-tegra.c
@@ -489,10 +489,8 @@ static int __init tegra_init_fuse(void)
size_t size = sizeof(*fuse->lookups) * fuse->soc->num_lookups;
fuse->lookups = kmemdup(fuse->soc->lookups, size, GFP_KERNEL);
- if (!fuse->lookups)
- return -ENOMEM;
-
- nvmem_add_cell_lookups(fuse->lookups, fuse->soc->num_lookups);
+ if (fuse->lookups)
+ nvmem_add_cell_lookups(fuse->lookups, fuse->soc->num_lookups);
}
return 0;
diff --git a/drivers/soc/tegra/fuse/fuse-tegra30.c b/drivers/soc/tegra/fuse/fuse-tegra30.c
index 9ea7f0168457..c1aa7815bd6e 100644
--- a/drivers/soc/tegra/fuse/fuse-tegra30.c
+++ b/drivers/soc/tegra/fuse/fuse-tegra30.c
@@ -37,7 +37,8 @@
defined(CONFIG_ARCH_TEGRA_132_SOC) || \
defined(CONFIG_ARCH_TEGRA_210_SOC) || \
defined(CONFIG_ARCH_TEGRA_186_SOC) || \
- defined(CONFIG_ARCH_TEGRA_194_SOC)
+ defined(CONFIG_ARCH_TEGRA_194_SOC) || \
+ defined(CONFIG_ARCH_TEGRA_234_SOC)
static u32 tegra30_fuse_read_early(struct tegra_fuse *fuse, unsigned int offset)
{
if (WARN_ON(!fuse->base))
diff --git a/drivers/soc/tegra/pmc.c b/drivers/soc/tegra/pmc.c
index 8e3b78bb2ac2..2ace21db4ae8 100644
--- a/drivers/soc/tegra/pmc.c
+++ b/drivers/soc/tegra/pmc.c
@@ -38,6 +38,7 @@
#include <linux/pinctrl/pinctrl.h>
#include <linux/platform_device.h>
#include <linux/pm_domain.h>
+#include <linux/pm_opp.h>
#include <linux/reboot.h>
#include <linux/regmap.h>
#include <linux/reset.h>
@@ -428,6 +429,9 @@ struct tegra_pmc {
struct irq_chip irq;
struct notifier_block clk_nb;
+
+ bool core_domain_state_synced;
+ bool core_domain_registered;
};
static struct tegra_pmc *pmc = &(struct tegra_pmc) {
@@ -1302,12 +1306,107 @@ free_mem:
return err;
}
+bool tegra_pmc_core_domain_state_synced(void)
+{
+ return pmc->core_domain_state_synced;
+}
+
+static int
+tegra_pmc_core_pd_set_performance_state(struct generic_pm_domain *genpd,
+ unsigned int level)
+{
+ struct dev_pm_opp *opp;
+ int err;
+
+ opp = dev_pm_opp_find_level_ceil(&genpd->dev, &level);
+ if (IS_ERR(opp)) {
+ dev_err(&genpd->dev, "failed to find OPP for level %u: %pe\n",
+ level, opp);
+ return PTR_ERR(opp);
+ }
+
+ mutex_lock(&pmc->powergates_lock);
+ err = dev_pm_opp_set_opp(pmc->dev, opp);
+ mutex_unlock(&pmc->powergates_lock);
+
+ dev_pm_opp_put(opp);
+
+ if (err) {
+ dev_err(&genpd->dev, "failed to set voltage to %duV: %d\n",
+ level, err);
+ return err;
+ }
+
+ return 0;
+}
+
+static unsigned int
+tegra_pmc_core_pd_opp_to_performance_state(struct generic_pm_domain *genpd,
+ struct dev_pm_opp *opp)
+{
+ return dev_pm_opp_get_level(opp);
+}
+
+static int tegra_pmc_core_pd_add(struct tegra_pmc *pmc, struct device_node *np)
+{
+ struct generic_pm_domain *genpd;
+ const char *rname = "core";
+ int err;
+
+ genpd = devm_kzalloc(pmc->dev, sizeof(*genpd), GFP_KERNEL);
+ if (!genpd)
+ return -ENOMEM;
+
+ genpd->name = np->name;
+ genpd->set_performance_state = tegra_pmc_core_pd_set_performance_state;
+ genpd->opp_to_performance_state = tegra_pmc_core_pd_opp_to_performance_state;
+
+ err = devm_pm_opp_set_regulators(pmc->dev, &rname, 1);
+ if (err)
+ return dev_err_probe(pmc->dev, err,
+ "failed to set core OPP regulator\n");
+
+ err = pm_genpd_init(genpd, NULL, false);
+ if (err) {
+ dev_err(pmc->dev, "failed to init core genpd: %d\n", err);
+ return err;
+ }
+
+ err = of_genpd_add_provider_simple(np, genpd);
+ if (err) {
+ dev_err(pmc->dev, "failed to add core genpd: %d\n", err);
+ goto remove_genpd;
+ }
+
+ pmc->core_domain_registered = true;
+
+ return 0;
+
+remove_genpd:
+ pm_genpd_remove(genpd);
+
+ return err;
+}
+
static int tegra_powergate_init(struct tegra_pmc *pmc,
struct device_node *parent)
{
+ struct of_phandle_args child_args, parent_args;
struct device_node *np, *child;
int err = 0;
+ /*
+ * Core power domain is the parent of powergate domains, hence it
+ * should be registered first.
+ */
+ np = of_get_child_by_name(parent, "core-domain");
+ if (np) {
+ err = tegra_pmc_core_pd_add(pmc, np);
+ of_node_put(np);
+ if (err)
+ return err;
+ }
+
np = of_get_child_by_name(parent, "powergates");
if (!np)
return 0;
@@ -1318,6 +1417,21 @@ static int tegra_powergate_init(struct tegra_pmc *pmc,
of_node_put(child);
break;
}
+
+ if (of_parse_phandle_with_args(child, "power-domains",
+ "#power-domain-cells",
+ 0, &parent_args))
+ continue;
+
+ child_args.np = child;
+ child_args.args_count = 0;
+
+ err = of_genpd_add_subdomain(&parent_args, &child_args);
+ of_node_put(parent_args.np);
+ if (err) {
+ of_node_put(child);
+ break;
+ }
}
of_node_put(np);
@@ -1361,6 +1475,12 @@ static void tegra_powergate_remove_all(struct device_node *parent)
}
of_node_put(np);
+
+ np = of_get_child_by_name(parent, "core-domain");
+ if (np) {
+ of_genpd_del_provider(np);
+ of_genpd_remove_last(np);
+ }
}
static const struct tegra_io_pad_soc *
@@ -3672,6 +3792,29 @@ static const struct of_device_id tegra_pmc_match[] = {
{ }
};
+static void tegra_pmc_sync_state(struct device *dev)
+{
+ int err;
+
+ /*
+ * Older device-trees don't have core PD, and thus, there are
+ * no dependencies that will block the state syncing. We shouldn't
+ * mark the domain as synced in this case.
+ */
+ if (!pmc->core_domain_registered)
+ return;
+
+ pmc->core_domain_state_synced = true;
+
+ /* this is a no-op if core regulator isn't used */
+ mutex_lock(&pmc->powergates_lock);
+ err = dev_pm_opp_sync_regulators(dev);
+ mutex_unlock(&pmc->powergates_lock);
+
+ if (err)
+ dev_err(dev, "failed to sync regulators: %d\n", err);
+}
+
static struct platform_driver tegra_pmc_driver = {
.driver = {
.name = "tegra-pmc",
@@ -3680,6 +3823,7 @@ static struct platform_driver tegra_pmc_driver = {
#if defined(CONFIG_PM_SLEEP) && defined(CONFIG_ARM)
.pm = &tegra_pmc_pm_ops,
#endif
+ .sync_state = tegra_pmc_sync_state,
},
.probe = tegra_pmc_probe,
};
diff --git a/drivers/soc/tegra/regulators-tegra20.c b/drivers/soc/tegra/regulators-tegra20.c
index 367a71a3cd10..b8ce9fd0650d 100644
--- a/drivers/soc/tegra/regulators-tegra20.c
+++ b/drivers/soc/tegra/regulators-tegra20.c
@@ -12,16 +12,22 @@
#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 <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;
+ int core_min_uV, cpu_min_uV;
+ bool sys_reboot_mode_req;
+ bool sys_reboot_mode;
};
static inline struct tegra_regulator_coupler *
@@ -38,6 +44,21 @@ 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 +79,7 @@ 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;
}
@@ -242,6 +263,10 @@ 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 +275,10 @@ 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);
+
if (cpu_min_uV > cpu_uV) {
err = tegra20_core_rtc_update(tegra, core_rdev, rtc_rdev,
cpu_uV, cpu_min_uV);
@@ -290,6 +319,8 @@ static int tegra20_regulator_balance_voltage(struct regulator_coupler *coupler,
return -EINVAL;
}
+ tegra->sys_reboot_mode = READ_ONCE(tegra->sys_reboot_mode_req);
+
if (rdev == cpu_rdev)
return tegra20_cpu_voltage_update(tegra, cpu_rdev,
core_rdev, rtc_rdev);
@@ -303,6 +334,51 @@ static int tegra20_regulator_balance_voltage(struct regulator_coupler *coupler,
return -EPERM;
}
+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 +411,14 @@ 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 +443,19 @@ 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,
};
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);
+
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 0e776b20f625..e74bbc9c7859 100644
--- a/drivers/soc/tegra/regulators-tegra30.c
+++ b/drivers/soc/tegra/regulators-tegra30.c
@@ -12,17 +12,22 @@
#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 <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;
- int core_min_uV;
+ struct notifier_block reboot_notifier;
+ int core_min_uV, cpu_min_uV;
+ bool sys_reboot_mode_req;
+ bool sys_reboot_mode;
};
static inline struct tegra_regulator_coupler *
@@ -39,6 +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;
@@ -59,7 +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;
}
@@ -172,6 +192,10 @@ static int tegra30_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
@@ -195,6 +219,10 @@ static int tegra30_voltage_update(struct tegra_regulator_coupler *tegra,
if (err)
return err;
+ /* restore boot voltage level */
+ if (tegra->sys_reboot_mode)
+ cpu_min_uV = max(cpu_min_uV, tegra->cpu_min_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);
@@ -263,9 +291,56 @@ static int tegra30_regulator_balance_voltage(struct regulator_coupler *coupler,
return -EINVAL;
}
+ tegra->sys_reboot_mode = READ_ONCE(tegra->sys_reboot_mode_req);
+
return tegra30_voltage_update(tegra, cpu_rdev, core_rdev);
}
+static int tegra30_regulator_prepare_reboot(struct tegra_regulator_coupler *tegra,
+ bool sys_reboot_mode)
+{
+ int err;
+
+ if (!tegra->core_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 tegra30_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 = tegra30_regulator_prepare_reboot(tegra, true);
+
+ return notifier_from_errno(ret);
+}
+
static int tegra30_regulator_attach(struct regulator_coupler *coupler,
struct regulator_dev *rdev)
{
@@ -292,6 +367,14 @@ static int tegra30_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;
@@ -311,13 +394,19 @@ static struct tegra_regulator_coupler tegra30_coupler = {
.detach_regulator = tegra30_regulator_detach,
.balance_voltage = tegra30_regulator_balance_voltage,
},
+ .reboot_notifier.notifier_call = tegra30_regulator_reboot,
};
static int __init tegra_regulator_coupler_init(void)
{
+ int err;
+
if (!of_machine_is_compatible("nvidia,tegra30"))
return 0;
+ err = register_reboot_notifier(&tegra30_coupler.reboot_notifier);
+ WARN_ON(err);
+
return regulator_coupler_register(&tegra30_coupler.coupler);
}
arch_initcall(tegra_regulator_coupler_init);