regulator: tps65910: Sleep control through external inputs

Add support for sleep controls of different regulator through
external inputs EN1, EN2 or EN3.
Each regulator's output will be active when its external
input is high and turns to OFF/Low power mode when its
external input is low.
The configuration parameters for sleep control is provided through
board specific platform data.
Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

drivers/regulator/tps65910-regulator.c

@@ -26,6 +26,9 @@
 #include <linux/mfd/tps65910.h>
 
 #define TPS65910_SUPPLY_STATE_ENABLED	0x1
+#define EXT_SLEEP_CONTROL (TPS65910_SLEEP_CONTROL_EXT_INPUT_EN1 |	\
+			TPS65910_SLEEP_CONTROL_EXT_INPUT_EN2 |		\
+			TPS65910_SLEEP_CONTROL_EXT_INPUT_EN3)
 
 /* supported VIO voltages in milivolts */
 static const u16 VIO_VSEL_table[] = {
@@ -252,6 +255,39 @@ static struct tps_info tps65911_regs[] = {
 	},
 };
 
+#define EXT_CONTROL_REG_BITS(id, regs_offs, bits) (((regs_offs) << 8) | (bits))
+static unsigned int tps65910_ext_sleep_control[] = {
+	0,
+	EXT_CONTROL_REG_BITS(VIO,    1, 0),
+	EXT_CONTROL_REG_BITS(VDD1,   1, 1),
+	EXT_CONTROL_REG_BITS(VDD2,   1, 2),
+	EXT_CONTROL_REG_BITS(VDD3,   1, 3),
+	EXT_CONTROL_REG_BITS(VDIG1,  0, 1),
+	EXT_CONTROL_REG_BITS(VDIG2,  0, 2),
+	EXT_CONTROL_REG_BITS(VPLL,   0, 6),
+	EXT_CONTROL_REG_BITS(VDAC,   0, 7),
+	EXT_CONTROL_REG_BITS(VAUX1,  0, 3),
+	EXT_CONTROL_REG_BITS(VAUX2,  0, 4),
+	EXT_CONTROL_REG_BITS(VAUX33, 0, 5),
+	EXT_CONTROL_REG_BITS(VMMC,   0, 0),
+};
+
+static unsigned int tps65911_ext_sleep_control[] = {
+	0,
+	EXT_CONTROL_REG_BITS(VIO,     1, 0),
+	EXT_CONTROL_REG_BITS(VDD1,    1, 1),
+	EXT_CONTROL_REG_BITS(VDD2,    1, 2),
+	EXT_CONTROL_REG_BITS(VDDCTRL, 1, 3),
+	EXT_CONTROL_REG_BITS(LDO1,    0, 1),
+	EXT_CONTROL_REG_BITS(LDO2,    0, 2),
+	EXT_CONTROL_REG_BITS(LDO3,    0, 7),
+	EXT_CONTROL_REG_BITS(LDO4,    0, 6),
+	EXT_CONTROL_REG_BITS(LDO5,    0, 3),
+	EXT_CONTROL_REG_BITS(LDO6,    0, 0),
+	EXT_CONTROL_REG_BITS(LDO7,    0, 5),
+	EXT_CONTROL_REG_BITS(LDO8,    0, 4),
+};
+
 struct tps65910_reg {
 	struct regulator_desc *desc;
 	struct tps65910 *mfd;
@@ -261,6 +297,8 @@ struct tps65910_reg {
 	int num_regulators;
 	int mode;
 	int  (*get_ctrl_reg)(int);
+	unsigned int *ext_sleep_control;
+	unsigned int board_ext_control[TPS65910_NUM_REGS];
 };
 
 static inline int tps65910_read(struct tps65910_reg *pmic, u8 reg)
@@ -861,6 +899,131 @@ static struct regulator_ops tps65911_ops = {
 	.list_voltage		= tps65911_list_voltage,
 };
 
+static int tps65910_set_ext_sleep_config(struct tps65910_reg *pmic,
+		int id, int ext_sleep_config)
+{
+	struct tps65910 *mfd = pmic->mfd;
+	u8 regoffs = (pmic->ext_sleep_control[id] >> 8) & 0xFF;
+	u8 bit_pos = (1 << pmic->ext_sleep_control[id] & 0xFF);
+	int ret;
+
+	/*
+	 * Regulator can not be control from multiple external input EN1, EN2
+	 * and EN3 together.
+	 */
+	if (ext_sleep_config & EXT_SLEEP_CONTROL) {
+		int en_count;
+		en_count = ((ext_sleep_config &
+				TPS65910_SLEEP_CONTROL_EXT_INPUT_EN1) != 0);
+		en_count += ((ext_sleep_config &
+				TPS65910_SLEEP_CONTROL_EXT_INPUT_EN2) != 0);
+		en_count += ((ext_sleep_config &
+				TPS65910_SLEEP_CONTROL_EXT_INPUT_EN3) != 0);
+		if (en_count > 1) {
+			dev_err(mfd->dev,
+				"External sleep control flag is not proper\n");
+			return -EINVAL;
+		}
+	}
+
+	pmic->board_ext_control[id] = ext_sleep_config;
+
+	/* External EN1 control */
+	if (ext_sleep_config & TPS65910_SLEEP_CONTROL_EXT_INPUT_EN1)
+		ret = tps65910_set_bits(mfd,
+				TPS65910_EN1_LDO_ASS + regoffs, bit_pos);
+	else
+		ret = tps65910_clear_bits(mfd,
+				TPS65910_EN1_LDO_ASS + regoffs, bit_pos);
+	if (ret < 0) {
+		dev_err(mfd->dev,
+			"Error in configuring external control EN1\n");
+		return ret;
+	}
+
+	/* External EN2 control */
+	if (ext_sleep_config & TPS65910_SLEEP_CONTROL_EXT_INPUT_EN2)
+		ret = tps65910_set_bits(mfd,
+				TPS65910_EN2_LDO_ASS + regoffs, bit_pos);
+	else
+		ret = tps65910_clear_bits(mfd,
+				TPS65910_EN2_LDO_ASS + regoffs, bit_pos);
+	if (ret < 0) {
+		dev_err(mfd->dev,
+			"Error in configuring external control EN2\n");
+		return ret;
+	}
+
+	/* External EN3 control for TPS65910 LDO only */
+	if ((tps65910_chip_id(mfd) == TPS65910) &&
+			(id >= TPS65910_REG_VDIG1)) {
+		if (ext_sleep_config & TPS65910_SLEEP_CONTROL_EXT_INPUT_EN3)
+			ret = tps65910_set_bits(mfd,
+				TPS65910_EN3_LDO_ASS + regoffs, bit_pos);
+		else
+			ret = tps65910_clear_bits(mfd,
+				TPS65910_EN3_LDO_ASS + regoffs, bit_pos);
+		if (ret < 0) {
+			dev_err(mfd->dev,
+				"Error in configuring external control EN3\n");
+			return ret;
+		}
+	}
+
+	/* Return if no external control is selected */
+	if (!(ext_sleep_config & EXT_SLEEP_CONTROL)) {
+		/* Clear all sleep controls */
+		ret = tps65910_clear_bits(mfd,
+			TPS65910_SLEEP_KEEP_LDO_ON + regoffs, bit_pos);
+		if (!ret)
+			ret = tps65910_clear_bits(mfd,
+				TPS65910_SLEEP_SET_LDO_OFF + regoffs, bit_pos);
+		if (ret < 0)
+			dev_err(mfd->dev,
+				"Error in configuring SLEEP register\n");
+		return ret;
+	}
+
+	/*
+	 * For regulator that has separate operational and sleep register make
+	 * sure that operational is used and clear sleep register to turn
+	 * regulator off when external control is inactive
+	 */
+	if ((id == TPS65910_REG_VDD1) ||
+		(id == TPS65910_REG_VDD2) ||
+			((id == TPS65911_REG_VDDCTRL) &&
+				(tps65910_chip_id(mfd) == TPS65911))) {
+		int op_reg_add = pmic->get_ctrl_reg(id) + 1;
+		int sr_reg_add = pmic->get_ctrl_reg(id) + 2;
+		int opvsel = tps65910_reg_read(pmic, op_reg_add);
+		int srvsel = tps65910_reg_read(pmic, sr_reg_add);
+		if (opvsel & VDD1_OP_CMD_MASK) {
+			u8 reg_val = srvsel & VDD1_OP_SEL_MASK;
+			ret = tps65910_reg_write(pmic, op_reg_add, reg_val);
+			if (ret < 0) {
+				dev_err(mfd->dev,
+					"Error in configuring op register\n");
+				return ret;
+			}
+		}
+		ret = tps65910_reg_write(pmic, sr_reg_add, 0);
+		if (ret < 0) {
+			dev_err(mfd->dev, "Error in settting sr register\n");
+			return ret;
+		}
+	}
+
+	ret = tps65910_clear_bits(mfd,
+			TPS65910_SLEEP_KEEP_LDO_ON + regoffs, bit_pos);
+	if (!ret)
+		ret = tps65910_set_bits(mfd,
+			TPS65910_SLEEP_SET_LDO_OFF + regoffs, bit_pos);
+	if (ret < 0)
+		dev_err(mfd->dev,
+			"Error in configuring SLEEP register\n");
+	return ret;
+}
+
 static __devinit int tps65910_probe(struct platform_device *pdev)
 {
 	struct tps65910 *tps65910 = dev_get_drvdata(pdev->dev.parent);
@@ -891,11 +1054,13 @@ static __devinit int tps65910_probe(struct platform_device *pdev)
 	case TPS65910:
 		pmic->get_ctrl_reg = &tps65910_get_ctrl_register;
 		pmic->num_regulators = ARRAY_SIZE(tps65910_regs);
+		pmic->ext_sleep_control = tps65910_ext_sleep_control;
 		info = tps65910_regs;
 		break;
 	case TPS65911:
 		pmic->get_ctrl_reg = &tps65911_get_ctrl_register;
 		pmic->num_regulators = ARRAY_SIZE(tps65911_regs);
+		pmic->ext_sleep_control = tps65911_ext_sleep_control;
 		info = tps65911_regs;
 		break;
 	default:
@@ -958,6 +1123,16 @@ static __devinit int tps65910_probe(struct platform_device *pdev)
 				pmic->desc[i].ops = &tps65911_ops;
 		}
 
+		err = tps65910_set_ext_sleep_config(pmic, i,
+				pmic_plat_data->regulator_ext_sleep_control[i]);
+		/*
+		 * Failing on regulator for configuring externally control
+		 * is not a serious issue, just throw warning.
+		 */
+		if (err < 0)
+			dev_warn(tps65910->dev,
+				"Failed to initialise ext control config\n");
+
 		pmic->desc[i].type = REGULATOR_VOLTAGE;
 		pmic->desc[i].owner = THIS_MODULE;
 
@@ -1004,6 +1179,36 @@ static int __devexit tps65910_remove(struct platform_device *pdev)
 	return 0;
 }
 
+static void tps65910_shutdown(struct platform_device *pdev)
+{
+	struct tps65910_reg *pmic = platform_get_drvdata(pdev);
+	int i;
+
+	/*
+	 * Before bootloader jumps to kernel, it makes sure that required
+	 * external control signals are in desired state so that given rails
+	 * can be configure accordingly.
+	 * If rails are configured to be controlled from external control
+	 * then before shutting down/rebooting the system, the external
+	 * control configuration need to be remove from the rails so that
+	 * its output will be available as per register programming even
+	 * if external controls are removed. This is require when the POR
+	 * value of the control signals are not in active state and before
+	 * bootloader initializes it, the system requires the rail output
+	 * to be active for booting.
+	 */
+	for (i = 0; i < pmic->num_regulators; i++) {
+		int err;
+		if (!pmic->rdev[i])
+			continue;
+
+		err = tps65910_set_ext_sleep_config(pmic, i, 0);
+		if (err < 0)
+			dev_err(&pdev->dev,
+				"Error in clearing external control\n");
+	}
+}
+
 static struct platform_driver tps65910_driver = {
 	.driver = {
 		.name = "tps65910-pmic",
@@ -1011,6 +1216,7 @@ static struct platform_driver tps65910_driver = {
 	},
 	.probe = tps65910_probe,
 	.remove = __devexit_p(tps65910_remove),
+	.shutdown = tps65910_shutdown,
 };
 
 static int __init tps65910_init(void)

include/linux/mfd/tps65910.h

@@ -768,6 +768,13 @@
 /* Max number of TPS65910/11 regulators */
 #define TPS65910_NUM_REGS				13
 
+/* External sleep controls through EN1/EN2/EN3 inputs*/
+#define TPS65910_SLEEP_CONTROL_EXT_INPUT_EN1		0x1
+#define TPS65910_SLEEP_CONTROL_EXT_INPUT_EN2		0x2
+#define TPS65910_SLEEP_CONTROL_EXT_INPUT_EN3		0x4
+/* TPS65911 names the EN3 signal as SLEEP */
+#define TPS65911_SLEEP_CONTROL_EXT_INPUT_SLEEP		0x4
+
 /**
  * struct tps65910_board
  * Board platform data may be used to initialize regulators.
@@ -779,6 +786,7 @@ struct tps65910_board {
 	int irq_base;
 	int vmbch_threshold;
 	int vmbch2_threshold;
+	unsigned long regulator_ext_sleep_control[TPS65910_NUM_REGS];
 	struct regulator_init_data *tps65910_pmic_init_data[TPS65910_NUM_REGS];
 };