[PATCH 1/2] regulator: act8945: Implement PM functionalities

[<Claudiu.Beznea@microchip.com>]

From: Boris Brezillon <boris.brezillon@bootlin.com>

The regulator supports a dedicated suspend mode.
Implement the appropriate ->set_suspend_xx() hooks, add support for
->set_mode(), and provide basic PM ops functionalities to setup the
regulator in a suspend state when the system is entering suspend.

We also implement the ->shutdown() method to make sure the PMIC will
not enter the suspend state when the system is shutdown.

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
[claudiu.beznea@microchip.com: remove dev_pm_ops, fix checkpatch warking, adapt commit message]
Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
---
 drivers/regulator/act8945a-regulator.c | 195 ++++++++++++++++++++++++++++++++-
 1 file changed, 193 insertions(+), 2 deletions(-)

diff --git a/drivers/regulator/act8945a-regulator.c b/drivers/regulator/act8945a-regulator.c
index 43fda8b4455a..41bf7d224abb 100644
--- a/drivers/regulator/act8945a-regulator.c
+++ b/drivers/regulator/act8945a-regulator.c
@@ -15,6 +15,7 @@
 #include <linux/module.h>
 #include <linux/of_device.h>
 #include <linux/platform_device.h>
+#include <linux/regmap.h>
 #include <linux/regulator/driver.h>
 #include <linux/regulator/machine.h>
 
@@ -23,23 +24,36 @@
  */
 #define ACT8945A_SYS_MODE	0x00
 #define ACT8945A_SYS_CTRL	0x01
+#define ACT8945A_SYS_UNLK_REGS	0x0b
 #define ACT8945A_DCDC1_VSET1	0x20
 #define ACT8945A_DCDC1_VSET2	0x21
 #define ACT8945A_DCDC1_CTRL	0x22
+#define ACT8945A_DCDC1_SUS	0x24
 #define ACT8945A_DCDC2_VSET1	0x30
 #define ACT8945A_DCDC2_VSET2	0x31
 #define ACT8945A_DCDC2_CTRL	0x32
+#define ACT8945A_DCDC2_SUS	0x34
 #define ACT8945A_DCDC3_VSET1	0x40
 #define ACT8945A_DCDC3_VSET2	0x41
 #define ACT8945A_DCDC3_CTRL	0x42
+#define ACT8945A_DCDC3_SUS	0x44
+
+#define ACT8945A_DCDC_MODE_MSK		BIT(5)
+#define ACT8945A_DCDC_MODE_FIXED	BIT(5)
+#define ACT8945A_DCDC_MODE_POWER_SAVING	(0)
+
 #define ACT8945A_LDO1_VSET	0x50
 #define ACT8945A_LDO1_CTRL	0x51
+#define ACT8945A_LDO1_SUS	0x52
 #define ACT8945A_LDO2_VSET	0x54
 #define ACT8945A_LDO2_CTRL	0x55
+#define ACT8945A_LDO2_SUS	0x56
 #define ACT8945A_LDO3_VSET	0x60
 #define ACT8945A_LDO3_CTRL	0x61
+#define ACT8945A_LDO3_SUS	0x62
 #define ACT8945A_LDO4_VSET	0x64
 #define ACT8945A_LDO4_CTRL	0x65
+#define ACT8945A_LDO4_SUS	0x66
 
 /**
  * Field Definitions.
@@ -63,12 +77,154 @@ enum {
 	ACT8945A_REG_NUM,
 };
 
+struct act8945a_pmic {
+	struct regulator_dev *rdevs[ACT8945A_REG_NUM];
+	struct regmap *regmap;
+};
+
 static const struct regulator_linear_range act8945a_voltage_ranges[] = {
 	REGULATOR_LINEAR_RANGE(600000, 0, 23, 25000),
 	REGULATOR_LINEAR_RANGE(1200000, 24, 47, 50000),
 	REGULATOR_LINEAR_RANGE(2400000, 48, 63, 100000),
 };
 
+static int act8945a_set_suspend_state(struct regulator_dev *rdev, bool enable)
+{
+	struct regmap *regmap = rdev->regmap;
+	int id = rdev->desc->id, ret, reg, val;
+
+	switch (id) {
+	case ACT8945A_ID_DCDC1:
+		reg = ACT8945A_DCDC1_SUS;
+		val = 0xa8;
+		break;
+	case ACT8945A_ID_DCDC2:
+		reg = ACT8945A_DCDC2_SUS;
+		val = 0xa8;
+		break;
+	case ACT8945A_ID_DCDC3:
+		reg = ACT8945A_DCDC3_SUS;
+		val = 0xa8;
+		break;
+	case ACT8945A_ID_LDO1:
+		reg = ACT8945A_LDO1_SUS;
+		val = 0xe8;
+		break;
+	case ACT8945A_ID_LDO2:
+		reg = ACT8945A_LDO2_SUS;
+		val = 0xe8;
+		break;
+	case ACT8945A_ID_LDO3:
+		reg = ACT8945A_LDO3_SUS;
+		val = 0xe8;
+		break;
+	case ACT8945A_ID_LDO4:
+		reg = ACT8945A_LDO4_SUS;
+		val = 0xe8;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	if (enable)
+		val |= BIT(4);
+
+	/*
+	 * Ask the PMIC to enable/disable this output when entering hibernate
+	 * mode.
+	 */
+	ret = regmap_write(regmap, reg, val);
+	if (ret < 0)
+		return ret;
+
+	/*
+	 * Ask the PMIC to enter the suspend mode on the next PWRHLD
+	 * transition.
+	 */
+	return regmap_write(regmap, ACT8945A_SYS_CTRL, 0x42);
+}
+
+static int act8945a_set_suspend_enable(struct regulator_dev *rdev)
+{
+	return act8945a_set_suspend_state(rdev, true);
+}
+
+static int act8945a_set_suspend_disable(struct regulator_dev *rdev)
+{
+	return act8945a_set_suspend_state(rdev, false);
+}
+
+static unsigned int act8945a_of_map_mode(unsigned int mode)
+{
+	if (mode == ACT8945A_DCDC_MODE_POWER_SAVING)
+		return REGULATOR_MODE_STANDBY;
+
+	return REGULATOR_MODE_NORMAL;
+}
+
+static int act8945a_set_mode(struct regulator_dev *rdev, unsigned int mode)
+{
+	struct regmap *regmap = rdev->regmap;
+	int id = rdev->desc->id;
+	int reg, val;
+
+	switch (mode) {
+	case REGULATOR_MODE_STANDBY:
+		val = ACT8945A_DCDC_MODE_POWER_SAVING;
+		break;
+	case REGULATOR_MODE_NORMAL:
+		val = ACT8945A_DCDC_MODE_FIXED;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	switch (id) {
+	case ACT8945A_ID_DCDC1:
+		reg = ACT8945A_DCDC1_CTRL;
+		break;
+	case ACT8945A_ID_DCDC2:
+		reg = ACT8945A_DCDC2_CTRL;
+		break;
+	case ACT8945A_ID_DCDC3:
+		reg = ACT8945A_DCDC3_CTRL;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return regmap_update_bits(regmap, reg, ACT8945A_DCDC_MODE_MSK, val);
+}
+
+static unsigned int act8945a_get_mode(struct regulator_dev *rdev)
+{
+	struct regmap *regmap = rdev->regmap;
+	int id = rdev->desc->id;
+	unsigned int val;
+	int reg;
+
+	switch (id) {
+	case ACT8945A_ID_DCDC1:
+		reg = ACT8945A_DCDC1_CTRL;
+		break;
+	case ACT8945A_ID_DCDC2:
+		reg = ACT8945A_DCDC2_CTRL;
+		break;
+	case ACT8945A_ID_DCDC3:
+		reg = ACT8945A_DCDC3_CTRL;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	regmap_read(regmap, reg, &val);
+
+	if ((val & ACT8945A_DCDC_MODE_MSK) == ACT8945A_DCDC_MODE_POWER_SAVING)
+		return REGULATOR_MODE_STANDBY;
+
+	return REGULATOR_MODE_NORMAL;
+}
+
 static const struct regulator_ops act8945a_ops = {
 	.list_voltage		= regulator_list_voltage_linear_range,
 	.map_voltage		= regulator_map_voltage_linear_range,
@@ -76,7 +232,11 @@ static const struct regulator_ops act8945a_ops = {
 	.set_voltage_sel	= regulator_set_voltage_sel_regmap,
 	.enable			= regulator_enable_regmap,
 	.disable		= regulator_disable_regmap,
+	.set_mode		= act8945a_set_mode,
+	.get_mode		= act8945a_get_mode,
 	.is_enabled		= regulator_is_enabled_regmap,
+	.set_suspend_enable	= act8945a_set_suspend_enable,
+	.set_suspend_disable	= act8945a_set_suspend_disable,
 };
 
 #define ACT89xx_REG(_name, _family, _id, _vsel_reg, _supply)		\
@@ -84,6 +244,7 @@ static const struct regulator_ops act8945a_ops = {
 		.name			= _name,			\
 		.supply_name		= _supply,			\
 		.of_match		= of_match_ptr("REG_"#_id),	\
+		.of_map_mode		= act8945a_of_map_mode,		\
 		.regulators_node	= of_match_ptr("regulators"),	\
 		.id			= _family##_ID_##_id,		\
 		.type			= REGULATOR_VOLTAGE,		\
@@ -122,10 +283,22 @@ static int act8945a_pmic_probe(struct platform_device *pdev)
 {
 	struct regulator_config config = { };
 	const struct regulator_desc *regulators;
+	struct act8945a_pmic *act8945a;
 	struct regulator_dev *rdev;
 	int i, num_regulators;
 	bool voltage_select;
 
+	act8945a = devm_kzalloc(&pdev->dev, sizeof(*act8945a), GFP_KERNEL);
+	if (!act8945a)
+		return -ENOMEM;
+
+	act8945a->regmap = dev_get_regmap(pdev->dev.parent, NULL);
+	if (!act8945a->regmap) {
+		dev_err(&pdev->dev,
+			"could not retrieve regmap from parent device\n");
+		return -EINVAL;
+	}
+
 	voltage_select = of_property_read_bool(pdev->dev.parent->of_node,
 					       "active-semi,vsel-high");
 
@@ -140,16 +313,33 @@ static int act8945a_pmic_probe(struct platform_device *pdev)
 	config.dev = &pdev->dev;
 	config.dev->of_node = pdev->dev.parent->of_node;
 	for (i = 0; i < num_regulators; i++) {
-		rdev = devm_regulator_register(&pdev->dev, &regulators[i], &config);
+		rdev = devm_regulator_register(&pdev->dev, &regulators[i],
+					       &config);
 		if (IS_ERR(rdev)) {
 			dev_err(&pdev->dev,
 				"failed to register %s regulator\n",
 				regulators[i].name);
 			return PTR_ERR(rdev);
 		}
+
+		act8945a->rdevs[i] = rdev;
 	}
 
-	return 0;
+	platform_set_drvdata(pdev, act8945a);
+
+	/* Unlock expert registers. */
+	return regmap_write(act8945a->regmap, ACT8945A_SYS_UNLK_REGS, 0xef);
+}
+
+static void act8945a_pmic_shutdown(struct platform_device *pdev)
+{
+	struct act8945a_pmic *act8945a = platform_get_drvdata(pdev);
+	struct regmap *regmap = act8945a->regmap;
+
+	/*
+	 * Ask the PMIC to shutdown everything on the next PWRHLD transition.
+	 */
+	regmap_write(regmap, ACT8945A_SYS_CTRL, 0x0);
 }
 
 static struct platform_driver act8945a_pmic_driver = {
@@ -157,6 +347,7 @@ static struct platform_driver act8945a_pmic_driver = {
 		.name = "act8945a-regulator",
 	},
 	.probe = act8945a_pmic_probe,
+	.shutdown = act8945a_pmic_shutdown,
 };
 module_platform_driver(act8945a_pmic_driver);
 
-- 
2.7.4