[PATCH V5 02/18] pinctrl: tegra: Add suspend and resume support

[Sowjanya Komatineni <skomatineni@nvidia.com>]

This patch adds support for Tegra pinctrl driver suspend and resume.

During suspend, context of all pinctrl registers are stored and
on resume they are all restored to have all the pinmux and pad
configuration for normal operation.

Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
---
 drivers/pinctrl/tegra/pinctrl-tegra.c    | 52 ++++++++++++++++++++++++++++++++
 drivers/pinctrl/tegra/pinctrl-tegra.h    |  3 ++
 drivers/pinctrl/tegra/pinctrl-tegra210.c |  1 +
 3 files changed, 56 insertions(+)

diff --git a/drivers/pinctrl/tegra/pinctrl-tegra.c b/drivers/pinctrl/tegra/pinctrl-tegra.c
index 34596b246578..e7c0a1011cba 100644
--- a/drivers/pinctrl/tegra/pinctrl-tegra.c
+++ b/drivers/pinctrl/tegra/pinctrl-tegra.c
@@ -621,6 +621,43 @@ static void tegra_pinctrl_clear_parked_bits(struct tegra_pmx *pmx)
 	}
 }
 
+static int tegra_pinctrl_suspend(struct device *dev)
+{
+	struct tegra_pmx *pmx = dev_get_drvdata(dev);
+	u32 *backup_regs = pmx->backup_regs;
+	u32 *regs;
+	unsigned int i, j;
+
+	for (i = 0; i < pmx->nbanks; i++) {
+		regs = pmx->regs[i];
+		for (j = 0; j < pmx->reg_bank_size[i] / 4; j++)
+			*backup_regs++ = readl(regs++);
+	}
+
+	return pinctrl_force_sleep(pmx->pctl);
+}
+
+static int tegra_pinctrl_resume(struct device *dev)
+{
+	struct tegra_pmx *pmx = dev_get_drvdata(dev);
+	u32 *backup_regs = pmx->backup_regs;
+	u32 *regs;
+	unsigned int i, j;
+
+	for (i = 0; i < pmx->nbanks; i++) {
+		regs = pmx->regs[i];
+		for (j = 0; j < pmx->reg_bank_size[i] / 4; j++)
+			writel(*backup_regs++, regs++);
+	}
+
+	return 0;
+}
+
+const struct dev_pm_ops tegra_pinctrl_pm = {
+	.suspend = &tegra_pinctrl_suspend,
+	.resume = &tegra_pinctrl_resume
+};
+
 static bool gpio_node_has_range(const char *compatible)
 {
 	struct device_node *np;
@@ -645,6 +682,7 @@ int tegra_pinctrl_probe(struct platform_device *pdev,
 	int i;
 	const char **group_pins;
 	int fn, gn, gfn;
+	unsigned long backup_regs_size = 0;
 
 	pmx = devm_kzalloc(&pdev->dev, sizeof(*pmx), GFP_KERNEL);
 	if (!pmx)
@@ -697,6 +735,7 @@ int tegra_pinctrl_probe(struct platform_device *pdev,
 		res = platform_get_resource(pdev, IORESOURCE_MEM, i);
 		if (!res)
 			break;
+		backup_regs_size += resource_size(res);
 	}
 	pmx->nbanks = i;
 
@@ -705,11 +744,24 @@ int tegra_pinctrl_probe(struct platform_device *pdev,
 	if (!pmx->regs)
 		return -ENOMEM;
 
+	pmx->reg_bank_size = devm_kcalloc(&pdev->dev, pmx->nbanks,
+					  sizeof(*pmx->reg_bank_size),
+					  GFP_KERNEL);
+	if (!pmx->reg_bank_size)
+		return -ENOMEM;
+
+	pmx->backup_regs = devm_kzalloc(&pdev->dev, backup_regs_size,
+					GFP_KERNEL);
+	if (!pmx->backup_regs)
+		return -ENOMEM;
+
 	for (i = 0; i < pmx->nbanks; i++) {
 		res = platform_get_resource(pdev, IORESOURCE_MEM, i);
 		pmx->regs[i] = devm_ioremap_resource(&pdev->dev, res);
 		if (IS_ERR(pmx->regs[i]))
 			return PTR_ERR(pmx->regs[i]);
+
+		pmx->reg_bank_size[i] = resource_size(res);
 	}
 
 	pmx->pctl = devm_pinctrl_register(&pdev->dev, &tegra_pinctrl_desc, pmx);
diff --git a/drivers/pinctrl/tegra/pinctrl-tegra.h b/drivers/pinctrl/tegra/pinctrl-tegra.h
index 287702660783..55456f8d44cf 100644
--- a/drivers/pinctrl/tegra/pinctrl-tegra.h
+++ b/drivers/pinctrl/tegra/pinctrl-tegra.h
@@ -17,6 +17,8 @@ struct tegra_pmx {
 
 	int nbanks;
 	void __iomem **regs;
+	size_t *reg_bank_size;
+	u32 *backup_regs;
 };
 
 enum tegra_pinconf_param {
@@ -193,6 +195,7 @@ struct tegra_pinctrl_soc_data {
 	bool drvtype_in_mux;
 };
 
+extern const struct dev_pm_ops tegra_pinctrl_pm;
 int tegra_pinctrl_probe(struct platform_device *pdev,
 			const struct tegra_pinctrl_soc_data *soc_data);
 #endif
diff --git a/drivers/pinctrl/tegra/pinctrl-tegra210.c b/drivers/pinctrl/tegra/pinctrl-tegra210.c
index 0b56ad5c9c1c..edd3f4606cdb 100644
--- a/drivers/pinctrl/tegra/pinctrl-tegra210.c
+++ b/drivers/pinctrl/tegra/pinctrl-tegra210.c
@@ -1571,6 +1571,7 @@ static struct platform_driver tegra210_pinctrl_driver = {
 	.driver = {
 		.name = "tegra210-pinctrl",
 		.of_match_table = tegra210_pinctrl_of_match,
+		.pm = &tegra_pinctrl_pm,
 	},
 	.probe = tegra210_pinctrl_probe,
 };
-- 
2.7.4