[PATCH 5/5] regulator: tps65090: add external control support for DCDC

[Laxman Dewangan <ldewangan@nvidia.com>]

The TPS65090's DCDC outut can also be enable/disable through the
external digital input signal. Add support for enable/disable
either through register access via I2C or through external
control inputs. The external control inputs can be driven through
GPIOs also and hence adding support for passing the GPIO number.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
---
 drivers/regulator/tps65090-regulator.c       |  130 +++++++++++++++++++++++---
 include/linux/regulator/tps65090-regulator.h |    6 +
 2 files changed, 122 insertions(+), 14 deletions(-)

diff --git a/drivers/regulator/tps65090-regulator.c b/drivers/regulator/tps65090-regulator.c
index 279154b..e3f130f 100644
--- a/drivers/regulator/tps65090-regulator.c
+++ b/drivers/regulator/tps65090-regulator.c
@@ -18,6 +18,7 @@
 
 #include <linux/module.h>
 #include <linux/init.h>
+#include <linux/gpio.h>
 #include <linux/slab.h>
 #include <linux/err.h>
 #include <linux/platform_device.h>
@@ -33,6 +34,18 @@ struct tps65090_regulator {
 	struct regulator_dev	*rdev;
 };
 
+static inline bool is_dcdc(int id)
+{
+	switch (id) {
+	case TPS65090_REGULATOR_DCDC1:
+	case TPS65090_REGULATOR_DCDC2:
+	case TPS65090_REGULATOR_DCDC3:
+		return true;
+	default:
+		return false;
+	}
+}
+
 static int tps65090_voltage_get_voltage(struct regulator_dev *rdev)
 {
 	struct tps65090_regulator *ri = rdev_get_drvdata(rdev);
@@ -54,12 +67,17 @@ static int tps65090_voltage_list_voltage(struct regulator_dev *rdev,
 	return ri->microvolts;
 }
 
-static struct regulator_ops tps65090_ops = {
+static struct regulator_ops tps65090_ext_control_ops = {
+	.get_voltage	= tps65090_voltage_get_voltage,
+	.list_voltage	= tps65090_voltage_list_voltage,
+};
+
+static struct regulator_ops tps65090_reg_contol_ops = {
 	.get_voltage	= tps65090_voltage_get_voltage,
 	.list_voltage	= tps65090_voltage_list_voltage,
-	.enable = regulator_enable_regmap,
-	.disable = regulator_disable_regmap,
-	.is_enabled = regulator_is_enabled_regmap,
+	.enable		= regulator_enable_regmap,
+	.disable	= regulator_disable_regmap,
+	.is_enabled	= regulator_is_enabled_regmap,
 };
 
 static struct regulator_ops tps65090_ldo_ops = {
@@ -80,20 +98,76 @@ static struct regulator_ops tps65090_ldo_ops = {
 }
 
 static struct regulator_desc tps65090_regulator_desc[] = {
-	tps65090_REG_DESC(DCDC1, "vsys1",   0x0C, tps65090_ops),
-	tps65090_REG_DESC(DCDC2, "vsys2",   0x0D, tps65090_ops),
-	tps65090_REG_DESC(DCDC3, "vsys3",   0x0E, tps65090_ops),
-	tps65090_REG_DESC(FET1,  "infet1",  0x0F, tps65090_ops),
-	tps65090_REG_DESC(FET2,  "infet2",  0x10, tps65090_ops),
-	tps65090_REG_DESC(FET3,  "infet3",  0x11, tps65090_ops),
-	tps65090_REG_DESC(FET4,  "infet4",  0x12, tps65090_ops),
-	tps65090_REG_DESC(FET5,  "infet5",  0x13, tps65090_ops),
-	tps65090_REG_DESC(FET6,  "infet6",  0x14, tps65090_ops),
-	tps65090_REG_DESC(FET7,  "infet7",  0x15, tps65090_ops),
+	tps65090_REG_DESC(DCDC1, "vsys1",   0x0C, tps65090_reg_contol_ops),
+	tps65090_REG_DESC(DCDC2, "vsys2",   0x0D, tps65090_reg_contol_ops),
+	tps65090_REG_DESC(DCDC3, "vsys3",   0x0E, tps65090_reg_contol_ops),
+	tps65090_REG_DESC(FET1,  "infet1",  0x0F, tps65090_reg_contol_ops),
+	tps65090_REG_DESC(FET2,  "infet2",  0x10, tps65090_reg_contol_ops),
+	tps65090_REG_DESC(FET3,  "infet3",  0x11, tps65090_reg_contol_ops),
+	tps65090_REG_DESC(FET4,  "infet4",  0x12, tps65090_reg_contol_ops),
+	tps65090_REG_DESC(FET5,  "infet5",  0x13, tps65090_reg_contol_ops),
+	tps65090_REG_DESC(FET6,  "infet6",  0x14, tps65090_reg_contol_ops),
+	tps65090_REG_DESC(FET7,  "infet7",  0x15, tps65090_reg_contol_ops),
 	tps65090_REG_DESC(LDO1,  "vsys_l1", 0,    tps65090_ldo_ops),
 	tps65090_REG_DESC(LDO2,  "vsys_l2", 0,    tps65090_ldo_ops),
 };
 
+static int __devinit tps65090_set_ext_control(
+	struct tps65090_regulator *ri, bool enable)
+{
+	int ret;
+	struct device *parent = ri->dev->parent;
+	unsigned int reg_en_reg = ri->desc->enable_reg;
+
+	if (enable)
+		ret = tps65090_set_bits(parent, reg_en_reg, 1);
+	else
+		ret =  tps65090_clr_bits(parent, reg_en_reg, 1);
+	if (ret < 0)
+		dev_err(ri->dev, "Error in updating reg 0x%x\n", reg_en_reg);
+	return ret;
+}
+
+static int __devinit tps65090_regulator_disable_ext_control(
+		struct tps65090_regulator *ri,
+		struct tps65090_regulator_platform_data *tps_pdata)
+{
+	int ret = 0;
+	struct device *parent = ri->dev->parent;
+	unsigned int reg_en_reg = ri->desc->enable_reg;
+
+	/*
+	 * First enable output for internal control if require.
+	 * And then disable external control.
+	 */
+	if (tps_pdata->reg_init_data->constraints.always_on ||
+			tps_pdata->reg_init_data->constraints.boot_on) {
+		ret =  tps65090_set_bits(parent, reg_en_reg, 0);
+		if (ret < 0) {
+			dev_err(ri->dev, "Error in set reg 0x%x\n", reg_en_reg);
+			return ret;
+		}
+	}
+
+	return tps65090_set_ext_control(ri, false);
+}
+
+static void __devinit tps65090_configure_regulator_config(
+		struct tps65090_regulator_platform_data *tps_pdata,
+		struct regulator_config *config)
+{
+	if (gpio_is_valid(tps_pdata->gpio)) {
+		int gpio_flag = GPIOF_OUT_INIT_LOW;
+
+		if (tps_pdata->reg_init_data->constraints.always_on ||
+				tps_pdata->reg_init_data->constraints.boot_on)
+			gpio_flag = GPIOF_OUT_INIT_HIGH;
+
+		config->ena_gpio = tps_pdata->gpio;
+		config->ena_gpio_flags = gpio_flag;
+	}
+}
+
 static int __devinit tps65090_regulator_probe(struct platform_device *pdev)
 {
 	struct tps65090 *tps65090_mfd = dev_get_drvdata(pdev->dev.parent);
@@ -128,6 +202,23 @@ static int __devinit tps65090_regulator_probe(struct platform_device *pdev)
 		ri->dev = &pdev->dev;
 		ri->desc = &tps65090_regulator_desc[num];
 
+		/* Configure for external control for DCDC*/
+		if (tps_pdata && is_dcdc(num) && tps_pdata->reg_init_data) {
+			if (tps_pdata->enable_ext_control) {
+				tps65090_configure_regulator_config(
+						tps_pdata, &config);
+				ri->desc->ops = &tps65090_ext_control_ops;
+			} else {
+				ret = tps65090_regulator_disable_ext_control(
+						ri, tps_pdata);
+				if (ret < 0) {
+					dev_err(&pdev->dev,
+						"failed disable ext control\n");
+					goto scrub;
+				}
+			}
+		}
+
 		config.dev = &pdev->dev;
 		config.driver_data = ri;
 		config.regmap = tps65090_mfd->rmap;
@@ -146,6 +237,17 @@ static int __devinit tps65090_regulator_probe(struct platform_device *pdev)
 			goto scrub;
 		}
 		ri->rdev = rdev;
+
+		/* Enable external control if it is require */
+		if (tps_pdata && is_dcdc(num) && tps_pdata->reg_init_data &&
+				tps_pdata->enable_ext_control) {
+			ret = tps65090_set_ext_control(ri, true);
+			if (ret < 0) {
+				/* Increment num to get unregister rdev */
+				num++;
+				goto scrub;
+			}
+		}
 	}
 
 	platform_set_drvdata(pdev, pmic);
diff --git a/include/linux/regulator/tps65090-regulator.h b/include/linux/regulator/tps65090-regulator.h
index 0b29ffa..3822136 100644
--- a/include/linux/regulator/tps65090-regulator.h
+++ b/include/linux/regulator/tps65090-regulator.h
@@ -46,11 +46,17 @@ enum {
  *
  * @reg_init_data: The regulator init data.
  * @microvolts: The rail's voltage level.
+ * @enable_ext_control: Enable extrenal control or not. Only available for
+ *	DCDC1, DCDC2 and DCDC3.
+ * @gpio: Gpio number if external control is enabled and controlled through
+ *	gpio.
  */
 
 struct tps65090_regulator_platform_data {
 	struct regulator_init_data *reg_init_data;
 	int microvolts;
+	bool enable_ext_control;
+	int gpio;
 };
 
 #endif	/* __REGULATOR_TPS65090_H */
-- 
1.7.1.1