power: regulator: tps65941: add regulator support

The driver provides regulator set/get voltage
enable/disable functions for tps65941 family of PMICs.

Signed-off-by: Keerthy <j-keerthy@ti.com>
diff --git a/drivers/power/regulator/Kconfig b/drivers/power/regulator/Kconfig
index 56d68ee..25fc787 100644
--- a/drivers/power/regulator/Kconfig
+++ b/drivers/power/regulator/Kconfig
@@ -323,3 +323,13 @@
 	This enables implementation of driver-model regulator uclass
 	features for REGULATOR LP873X and the family of LP873X PMICs.
 	The driver implements get/set api for: value and enable in SPL.
+
+config DM_REGULATOR_TPS65941
+	bool "Enable driver for TPS65941 PMIC regulators"
+        depends on PMIC_TPS65941
+	help
+	This enables implementation of driver-model regulator uclass
+	features for REGULATOR TPS65941 and the family of TPS65941 PMICs.
+	TPS65941 series of PMICs have 5 single phase BUCKs that can also
+	be configured in multi phase modes & 4 LDOs. The driver implements
+	get/set api for value and enable.
diff --git a/drivers/power/regulator/Makefile b/drivers/power/regulator/Makefile
index 9198841..b611c90 100644
--- a/drivers/power/regulator/Makefile
+++ b/drivers/power/regulator/Makefile
@@ -28,3 +28,4 @@
 obj-$(CONFIG_DM_REGULATOR_TPS65910) += tps65910_regulator.o
 obj-$(CONFIG_DM_REGULATOR_TPS62360) += tps62360_regulator.o
 obj-$(CONFIG_$(SPL_)DM_REGULATOR_STPMIC1) += stpmic1.o
+obj-$(CONFIG_DM_REGULATOR_TPS65941) += tps65941_regulator.o
diff --git a/drivers/power/regulator/tps65941_regulator.c b/drivers/power/regulator/tps65941_regulator.c
new file mode 100644
index 0000000..a00ef58
--- /dev/null
+++ b/drivers/power/regulator/tps65941_regulator.c
@@ -0,0 +1,407 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * (C) Copyright 2019
+ * Texas Instruments Incorporated, <www.ti.com>
+ *
+ * Keerthy <j-keerthy@ti.com>
+ */
+
+#include <common.h>
+#include <fdtdec.h>
+#include <errno.h>
+#include <dm.h>
+#include <i2c.h>
+#include <power/pmic.h>
+#include <power/regulator.h>
+#include <power/tps65941.h>
+
+static const char tps65941_buck_ctrl[TPS65941_BUCK_NUM] = {0x4, 0x6, 0x8, 0xA,
+								0xC};
+static const char tps65941_buck_vout[TPS65941_BUCK_NUM] = {0xE, 0x10, 0x12,
+								0x14, 0x16};
+static const char tps65941_ldo_ctrl[TPS65941_BUCK_NUM] = {0x1D, 0x1E, 0x1F,
+								0x20};
+static const char tps65941_ldo_vout[TPS65941_BUCK_NUM] = {0x23, 0x24, 0x25,
+								0x26};
+
+static int tps65941_buck_enable(struct udevice *dev, int op, bool *enable)
+{
+	int ret;
+	unsigned int adr;
+	struct dm_regulator_uclass_platdata *uc_pdata;
+
+	uc_pdata = dev_get_uclass_platdata(dev);
+	adr = uc_pdata->ctrl_reg;
+
+	ret = pmic_reg_read(dev->parent, adr);
+	if (ret < 0)
+		return ret;
+
+	if (op == PMIC_OP_GET) {
+		ret &= TPS65941_BUCK_MODE_MASK;
+
+		if (ret)
+			*enable = true;
+		else
+			*enable = false;
+
+		return 0;
+	} else if (op == PMIC_OP_SET) {
+		if (*enable)
+			ret |= TPS65941_BUCK_MODE_MASK;
+		else
+			ret &= ~TPS65941_BUCK_MODE_MASK;
+		ret = pmic_reg_write(dev->parent, adr, ret);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+static int tps65941_buck_volt2val(int uV)
+{
+	if (uV > TPS65941_BUCK_VOLT_MAX)
+		return -EINVAL;
+	else if (uV > 1650000)
+		return (uV - 1660000) / 20000 + 0xAB;
+	else if (uV > 1110000)
+		return (uV - 1110000) / 10000 + 0x73;
+	else if (uV > 600000)
+		return (uV - 600000) / 5000 + 0x0F;
+	else if (uV >= 300000)
+		return (uV - 300000) / 20000 + 0x00;
+	else
+		return -EINVAL;
+}
+
+static int tps65941_buck_val2volt(int val)
+{
+	if (val > TPS65941_BUCK_VOLT_MAX_HEX)
+		return -EINVAL;
+	else if (val > 0xAB)
+		return 1660000 + (val - 0xAB) * 20000;
+	else if (val > 0x73)
+		return 1100000 + (val - 0x73) * 10000;
+	else if (val > 0xF)
+		return 600000 + (val - 0xF) * 5000;
+	else if (val >= 0x0)
+		return 300000 + val * 5000;
+	else
+		return -EINVAL;
+}
+
+int tps65941_lookup_slew(int id)
+{
+	switch (id) {
+	case 0:
+		return 33000;
+	case 1:
+		return 20000;
+	case 2:
+		return 10000;
+	case 3:
+		return 5000;
+	case 4:
+		return 2500;
+	case 5:
+		return 1300;
+	case 6:
+		return 630;
+	case 7:
+		return 310;
+	default:
+		return -1;
+	}
+}
+
+static int tps65941_buck_val(struct udevice *dev, int op, int *uV)
+{
+	unsigned int hex, adr;
+	int ret, delta, uwait, slew;
+	struct dm_regulator_uclass_platdata *uc_pdata;
+
+	uc_pdata = dev_get_uclass_platdata(dev);
+
+	if (op == PMIC_OP_GET)
+		*uV = 0;
+
+	adr = uc_pdata->volt_reg;
+
+	ret = pmic_reg_read(dev->parent, adr);
+	if (ret < 0)
+		return ret;
+
+	ret &= TPS65941_BUCK_VOLT_MASK;
+	ret = tps65941_buck_val2volt(ret);
+	if (ret < 0)
+		return ret;
+
+	if (op == PMIC_OP_GET) {
+		*uV = ret;
+		return 0;
+	}
+
+	/*
+	 * Compute the delta voltage, find the slew rate and wait
+	 * for the appropriate amount of time after voltage switch
+	 */
+	if (*uV > ret)
+		delta = *uV - ret;
+	else
+		delta = ret - *uV;
+
+	slew = pmic_reg_read(dev->parent, uc_pdata->ctrl_reg + 1);
+	if (slew < 0)
+		return ret;
+
+	slew &= TP65941_BUCK_CONF_SLEW_MASK;
+	slew = tps65941_lookup_slew(slew);
+	if (slew <= 0)
+		return ret;
+
+	uwait = delta / slew;
+
+	hex = tps65941_buck_volt2val(*uV);
+	if (hex < 0)
+		return hex;
+
+	ret &= 0x0;
+	ret = hex;
+
+	ret = pmic_reg_write(dev->parent, adr, ret);
+
+	udelay(uwait);
+
+	return ret;
+}
+
+static int tps65941_ldo_enable(struct udevice *dev, int op, bool *enable)
+{
+	int ret;
+	unsigned int adr;
+	struct dm_regulator_uclass_platdata *uc_pdata;
+
+	uc_pdata = dev_get_uclass_platdata(dev);
+	adr = uc_pdata->ctrl_reg;
+
+	ret = pmic_reg_read(dev->parent, adr);
+	if (ret < 0)
+		return ret;
+
+	if (op == PMIC_OP_GET) {
+		ret &= TPS65941_LDO_MODE_MASK;
+
+		if (ret)
+			*enable = true;
+		else
+			*enable = false;
+
+		return 0;
+	} else if (op == PMIC_OP_SET) {
+		if (*enable)
+			ret |= TPS65941_LDO_MODE_MASK;
+		else
+			ret &= ~TPS65941_LDO_MODE_MASK;
+		ret = pmic_reg_write(dev->parent, adr, ret);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+static int tps65941_ldo_val2volt(int val)
+{
+	if (val > TPS65941_LDO_VOLT_MAX_HEX || val < TPS65941_LDO_VOLT_MIN_HEX)
+		return -EINVAL;
+	else if (val >= TPS65941_LDO_VOLT_MIN_HEX)
+		return 600000 + (val - TPS65941_LDO_VOLT_MIN_HEX) * 50000;
+	else
+		return -EINVAL;
+}
+
+static int tps65941_ldo_val(struct udevice *dev, int op, int *uV)
+{
+	unsigned int hex, adr;
+	int ret;
+	struct dm_regulator_uclass_platdata *uc_pdata;
+
+	uc_pdata = dev_get_uclass_platdata(dev);
+
+	if (op == PMIC_OP_GET)
+		*uV = 0;
+
+	adr = uc_pdata->volt_reg;
+
+	ret = pmic_reg_read(dev->parent, adr);
+	if (ret < 0)
+		return ret;
+
+	ret &= TPS65941_LDO_VOLT_MASK;
+	ret = tps65941_ldo_val2volt(ret);
+	if (ret < 0)
+		return ret;
+
+	if (op == PMIC_OP_GET) {
+		*uV = ret;
+		return 0;
+	}
+
+	hex = tps65941_buck_volt2val(*uV);
+	if (hex < 0)
+		return hex;
+
+	ret &= 0x0;
+	ret = hex;
+
+	ret = pmic_reg_write(dev->parent, adr, ret);
+
+	return ret;
+}
+
+static int tps65941_ldo_probe(struct udevice *dev)
+{
+	struct dm_regulator_uclass_platdata *uc_pdata;
+	int idx;
+
+	uc_pdata = dev_get_uclass_platdata(dev);
+	uc_pdata->type = REGULATOR_TYPE_LDO;
+
+	idx = dev->driver_data;
+	if (idx == 1 || idx == 2 || idx == 3 || idx == 4) {
+		debug("Single phase regulator\n");
+	} else {
+		printf("Wrong ID for regulator\n");
+		return -EINVAL;
+	}
+
+	uc_pdata->ctrl_reg = tps65941_ldo_ctrl[idx - 1];
+	uc_pdata->volt_reg = tps65941_ldo_vout[idx - 1];
+
+	return 0;
+}
+
+static int tps65941_buck_probe(struct udevice *dev)
+{
+	struct dm_regulator_uclass_platdata *uc_pdata;
+	int idx;
+
+	uc_pdata = dev_get_uclass_platdata(dev);
+	uc_pdata->type = REGULATOR_TYPE_BUCK;
+
+	idx = dev->driver_data;
+	if (idx == 1 || idx == 2 || idx == 3 || idx == 4 || idx == 5) {
+		debug("Single phase regulator\n");
+	} else if (idx == 12) {
+		idx = 1;
+	} else if (idx == 34) {
+		idx = 3;
+	} else if (idx == 1234) {
+		idx = 1;
+	} else {
+		printf("Wrong ID for regulator\n");
+		return -EINVAL;
+	}
+
+	uc_pdata->ctrl_reg = tps65941_buck_ctrl[idx - 1];
+	uc_pdata->volt_reg = tps65941_buck_vout[idx - 1];
+
+	return 0;
+}
+
+static int ldo_get_value(struct udevice *dev)
+{
+	int uV;
+	int ret;
+
+	ret = tps65941_ldo_val(dev, PMIC_OP_GET, &uV);
+	if (ret)
+		return ret;
+
+	return uV;
+}
+
+static int ldo_set_value(struct udevice *dev, int uV)
+{
+	return tps65941_ldo_val(dev, PMIC_OP_SET, &uV);
+}
+
+static int ldo_get_enable(struct udevice *dev)
+{
+	bool enable = false;
+	int ret;
+
+	ret = tps65941_ldo_enable(dev, PMIC_OP_GET, &enable);
+	if (ret)
+		return ret;
+
+	return enable;
+}
+
+static int ldo_set_enable(struct udevice *dev, bool enable)
+{
+	return tps65941_ldo_enable(dev, PMIC_OP_SET, &enable);
+}
+
+static int buck_get_value(struct udevice *dev)
+{
+	int uV;
+	int ret;
+
+	ret = tps65941_buck_val(dev, PMIC_OP_GET, &uV);
+	if (ret)
+		return ret;
+
+	return uV;
+}
+
+static int buck_set_value(struct udevice *dev, int uV)
+{
+	return tps65941_buck_val(dev, PMIC_OP_SET, &uV);
+}
+
+static int buck_get_enable(struct udevice *dev)
+{
+	bool enable = false;
+	int ret;
+
+	ret = tps65941_buck_enable(dev, PMIC_OP_GET, &enable);
+	if (ret)
+		return ret;
+
+	return enable;
+}
+
+static int buck_set_enable(struct udevice *dev, bool enable)
+{
+	return tps65941_buck_enable(dev, PMIC_OP_SET, &enable);
+}
+
+static const struct dm_regulator_ops tps65941_ldo_ops = {
+	.get_value  = ldo_get_value,
+	.set_value  = ldo_set_value,
+	.get_enable = ldo_get_enable,
+	.set_enable = ldo_set_enable,
+};
+
+U_BOOT_DRIVER(tps65941_ldo) = {
+	.name = TPS65941_LDO_DRIVER,
+	.id = UCLASS_REGULATOR,
+	.ops = &tps65941_ldo_ops,
+	.probe = tps65941_ldo_probe,
+};
+
+static const struct dm_regulator_ops tps65941_buck_ops = {
+	.get_value  = buck_get_value,
+	.set_value  = buck_set_value,
+	.get_enable = buck_get_enable,
+	.set_enable = buck_set_enable,
+};
+
+U_BOOT_DRIVER(tps65941_buck) = {
+	.name = TPS65941_BUCK_DRIVER,
+	.id = UCLASS_REGULATOR,
+	.ops = &tps65941_buck_ops,
+	.probe = tps65941_buck_probe,
+};