Merge tag 'tegra-for-5.17-soc' of git://git.kernel.org/pub/scm/linux/kernel/git/tegra/linux into arm/drivers

soc/tegra: Changes for v5.17-rc1

This set of changes contains some preparatory work that is shared by
several branches and trees to support DVFS via power domains.

There's also a bit of cleanup and improvements to reboot on chips that
use PSCI.

* tag 'tegra-for-5.17-soc' of git://git.kernel.org/pub/scm/linux/kernel/git/tegra/linux:
  soc/tegra: pmc: Rename core power domain
  soc/tegra: pmc: Rename 3d power domains
  soc/tegra: regulators: Prepare for suspend
  soc/tegra: fuse: Use resource-managed helpers
  soc/tegra: fuse: Reset hardware
  soc/tegra: pmc: Add reboot notifier
  soc/tegra: Don't print error message when OPPs not available

Link: https://lore.kernel.org/r/20211217162253.1801077-1-thierry.reding@gmail.com
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

7 files changed, 326 insertions, 25 deletions

diff --git a/drivers/soc/tegra/common.c b/drivers/soc/tegra/common.c
index 35c882da55fc..32c346b72635 100644
--- a/drivers/soc/tegra/common.c
+++ b/drivers/soc/tegra/common.c
@@ -136,9 +136,7 @@ int devm_tegra_core_dev_init_opp_table(struct device *dev,
 	 */
 	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
+		if (err != -ENODEV)
 			dev_err(dev, "failed to add OPP table: %d\n", err);
 
 		return err;
diff --git a/drivers/soc/tegra/fuse/fuse-tegra.c b/drivers/soc/tegra/fuse/fuse-tegra.c
index f2151815db58..fe4f935ce73a 100644
--- a/drivers/soc/tegra/fuse/fuse-tegra.c
+++ b/drivers/soc/tegra/fuse/fuse-tegra.c
@@ -14,6 +14,7 @@
 #include <linux/of_address.h>
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
+#include <linux/reset.h>
 #include <linux/slab.h>
 #include <linux/sys_soc.h>
 
@@ -181,6 +182,12 @@ static const struct nvmem_cell_info tegra_fuse_cells[] = {
 	},
 };
 
+static void tegra_fuse_restore(void *base)
+{
+	fuse->clk = NULL;
+	fuse->base = base;
+}
+
 static int tegra_fuse_probe(struct platform_device *pdev)
 {
 	void __iomem *base = fuse->base;
@@ -188,13 +195,16 @@ static int tegra_fuse_probe(struct platform_device *pdev)
 	struct resource *res;
 	int err;
 
+	err = devm_add_action(&pdev->dev, tegra_fuse_restore, base);
+	if (err)
+		return err;
+
 	/* take over the memory region from the early initialization */
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	fuse->phys = res->start;
 	fuse->base = devm_ioremap_resource(&pdev->dev, res);
 	if (IS_ERR(fuse->base)) {
 		err = PTR_ERR(fuse->base);
-		fuse->base = base;
 		return err;
 	}
 
@@ -204,19 +214,20 @@ static int tegra_fuse_probe(struct platform_device *pdev)
 			dev_err(&pdev->dev, "failed to get FUSE clock: %ld",
 				PTR_ERR(fuse->clk));
 
-		fuse->base = base;
 		return PTR_ERR(fuse->clk);
 	}
 
 	platform_set_drvdata(pdev, fuse);
 	fuse->dev = &pdev->dev;
 
-	pm_runtime_enable(&pdev->dev);
+	err = devm_pm_runtime_enable(&pdev->dev);
+	if (err)
+		return err;
 
 	if (fuse->soc->probe) {
 		err = fuse->soc->probe(fuse);
 		if (err < 0)
-			goto restore;
+			return err;
 	}
 
 	memset(&nvmem, 0, sizeof(nvmem));
@@ -240,19 +251,37 @@ static int tegra_fuse_probe(struct platform_device *pdev)
 		err = PTR_ERR(fuse->nvmem);
 		dev_err(&pdev->dev, "failed to register NVMEM device: %d\n",
 			err);
-		goto restore;
+		return err;
+	}
+
+	fuse->rst = devm_reset_control_get_optional(&pdev->dev, "fuse");
+	if (IS_ERR(fuse->rst)) {
+		err = PTR_ERR(fuse->rst);
+		dev_err(&pdev->dev, "failed to get FUSE reset: %pe\n",
+			fuse->rst);
+		return err;
+	}
+
+	/*
+	 * FUSE clock is enabled at a boot time, hence this resume/suspend
+	 * disables the clock besides the h/w resetting.
+	 */
+	err = pm_runtime_resume_and_get(&pdev->dev);
+	if (err)
+		return err;
+
+	err = reset_control_reset(fuse->rst);
+	pm_runtime_put(&pdev->dev);
+
+	if (err < 0) {
+		dev_err(&pdev->dev, "failed to reset FUSE: %d\n", err);
+		return err;
 	}
 
 	/* release the early I/O memory mapping */
 	iounmap(base);
 
 	return 0;
-
-restore:
-	fuse->clk = NULL;
-	fuse->base = base;
-	pm_runtime_disable(&pdev->dev);
-	return err;
 }
 
 static int __maybe_unused tegra_fuse_runtime_resume(struct device *dev)
diff --git a/drivers/soc/tegra/fuse/fuse-tegra20.c b/drivers/soc/tegra/fuse/fuse-tegra20.c
index 8ec9fc5e5e4b..12503f563e36 100644
--- a/drivers/soc/tegra/fuse/fuse-tegra20.c
+++ b/drivers/soc/tegra/fuse/fuse-tegra20.c
@@ -94,9 +94,28 @@ static bool dma_filter(struct dma_chan *chan, void *filter_param)
 	return of_device_is_compatible(np, "nvidia,tegra20-apbdma");
 }
 
+static void tegra20_fuse_release_channel(void *data)
+{
+	struct tegra_fuse *fuse = data;
+
+	dma_release_channel(fuse->apbdma.chan);
+	fuse->apbdma.chan = NULL;
+}
+
+static void tegra20_fuse_free_coherent(void *data)
+{
+	struct tegra_fuse *fuse = data;
+
+	dma_free_coherent(fuse->dev, sizeof(u32), fuse->apbdma.virt,
+			  fuse->apbdma.phys);
+	fuse->apbdma.virt = NULL;
+	fuse->apbdma.phys = 0x0;
+}
+
 static int tegra20_fuse_probe(struct tegra_fuse *fuse)
 {
 	dma_cap_mask_t mask;
+	int err;
 
 	dma_cap_zero(mask);
 	dma_cap_set(DMA_SLAVE, mask);
@@ -105,13 +124,21 @@ static int tegra20_fuse_probe(struct tegra_fuse *fuse)
 	if (!fuse->apbdma.chan)
 		return -EPROBE_DEFER;
 
+	err = devm_add_action_or_reset(fuse->dev, tegra20_fuse_release_channel,
+				       fuse);
+	if (err)
+		return err;
+
 	fuse->apbdma.virt = dma_alloc_coherent(fuse->dev, sizeof(u32),
 					       &fuse->apbdma.phys,
 					       GFP_KERNEL);
-	if (!fuse->apbdma.virt) {
-		dma_release_channel(fuse->apbdma.chan);
+	if (!fuse->apbdma.virt)
 		return -ENOMEM;
-	}
+
+	err = devm_add_action_or_reset(fuse->dev, tegra20_fuse_free_coherent,
+				       fuse);
+	if (err)
+		return err;
 
 	fuse->apbdma.config.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
 	fuse->apbdma.config.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
diff --git a/drivers/soc/tegra/fuse/fuse.h b/drivers/soc/tegra/fuse/fuse.h
index de58feba0435..1b719d85bd04 100644
--- a/drivers/soc/tegra/fuse/fuse.h
+++ b/drivers/soc/tegra/fuse/fuse.h
@@ -43,6 +43,7 @@ struct tegra_fuse {
 	void __iomem *base;
 	phys_addr_t phys;
 	struct clk *clk;
+	struct reset_control *rst;
 
 	u32 (*read_early)(struct tegra_fuse *fuse, unsigned int offset);
 	u32 (*read)(struct tegra_fuse *fuse, unsigned int offset);
diff --git a/drivers/soc/tegra/pmc.c b/drivers/soc/tegra/pmc.c
index 575d6d5b4294..5aceacbd8ce0 100644
--- a/drivers/soc/tegra/pmc.c
+++ b/drivers/soc/tegra/pmc.c
@@ -1064,10 +1064,8 @@ int tegra_pmc_cpu_remove_clamping(unsigned int cpuid)
 	return tegra_powergate_remove_clamping(id);
 }
 
-static int tegra_pmc_restart_notify(struct notifier_block *this,
-				    unsigned long action, void *data)
+static void tegra_pmc_program_reboot_reason(const char *cmd)
 {
-	const char *cmd = data;
 	u32 value;
 
 	value = tegra_pmc_scratch_readl(pmc, pmc->soc->regs->scratch0);
@@ -1085,6 +1083,25 @@ static int tegra_pmc_restart_notify(struct notifier_block *this,
 	}
 
 	tegra_pmc_scratch_writel(pmc, value, pmc->soc->regs->scratch0);
+}
+
+static int tegra_pmc_reboot_notify(struct notifier_block *this,
+				   unsigned long action, void *data)
+{
+	if (action == SYS_RESTART)
+		tegra_pmc_program_reboot_reason(data);
+
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block tegra_pmc_reboot_notifier = {
+	.notifier_call = tegra_pmc_reboot_notify,
+};
+
+static int tegra_pmc_restart_notify(struct notifier_block *this,
+				    unsigned long action, void *data)
+{
+	u32 value;
 
 	/* reset everything but PMC_SCRATCH0 and PMC_RST_STATUS */
 	value = tegra_pmc_readl(pmc, PMC_CNTRL);
@@ -1353,7 +1370,7 @@ static int tegra_pmc_core_pd_add(struct tegra_pmc *pmc, struct device_node *np)
 	if (!genpd)
 		return -ENOMEM;
 
-	genpd->name = np->name;
+	genpd->name = "core";
 	genpd->set_performance_state = tegra_pmc_core_pd_set_performance_state;
 	genpd->opp_to_performance_state = tegra_pmc_core_pd_opp_to_performance_state;
 
@@ -2890,6 +2907,14 @@ static int tegra_pmc_probe(struct platform_device *pdev)
 			goto cleanup_sysfs;
 	}
 
+	err = devm_register_reboot_notifier(&pdev->dev,
+					    &tegra_pmc_reboot_notifier);
+	if (err) {
+		dev_err(&pdev->dev, "unable to register reboot notifier, %d\n",
+			err);
+		goto cleanup_debugfs;
+	}
+
 	err = register_restart_handler(&tegra_pmc_restart_handler);
 	if (err) {
 		dev_err(&pdev->dev, "unable to register restart handler, %d\n",
@@ -2963,7 +2988,7 @@ static SIMPLE_DEV_PM_OPS(tegra_pmc_pm_ops, tegra_pmc_suspend, tegra_pmc_resume);
 
 static const char * const tegra20_powergates[] = {
 	[TEGRA_POWERGATE_CPU] = "cpu",
-	[TEGRA_POWERGATE_3D] = "3d",
+	[TEGRA_POWERGATE_3D] = "td",
 	[TEGRA_POWERGATE_VENC] = "venc",
 	[TEGRA_POWERGATE_VDEC] = "vdec",
 	[TEGRA_POWERGATE_PCIE] = "pcie",
@@ -3071,7 +3096,7 @@ static const struct tegra_pmc_soc tegra20_pmc_soc = {
 
 static const char * const tegra30_powergates[] = {
 	[TEGRA_POWERGATE_CPU] = "cpu0",
-	[TEGRA_POWERGATE_3D] = "3d0",
+	[TEGRA_POWERGATE_3D] = "td",
 	[TEGRA_POWERGATE_VENC] = "venc",
 	[TEGRA_POWERGATE_VDEC] = "vdec",
 	[TEGRA_POWERGATE_PCIE] = "pcie",
@@ -3083,7 +3108,7 @@ static const char * const tegra30_powergates[] = {
 	[TEGRA_POWERGATE_CPU2] = "cpu2",
 	[TEGRA_POWERGATE_CPU3] = "cpu3",
 	[TEGRA_POWERGATE_CELP] = "celp",
-	[TEGRA_POWERGATE_3D1] = "3d1",
+	[TEGRA_POWERGATE_3D1] = "td2",
 };
 
 static const u8 tegra30_cpu_powergates[] = {
@@ -3132,7 +3157,7 @@ static const struct tegra_pmc_soc tegra30_pmc_soc = {
 
 static const char * const tegra114_powergates[] = {
 	[TEGRA_POWERGATE_CPU] = "crail",
-	[TEGRA_POWERGATE_3D] = "3d",
+	[TEGRA_POWERGATE_3D] = "td",
 	[TEGRA_POWERGATE_VENC] = "venc",
 	[TEGRA_POWERGATE_VDEC] = "vdec",
 	[TEGRA_POWERGATE_MPE] = "mpe",
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);