sandbox: add: sandbox PMIC device drivers: I2C emul, pmic, regulator

This commit adds emulation of sandbox PMIC device, which includes:
- PMIC I2C emulation driver
- PMIC I/O driver (UCLASS_PMIC)
- PMIC regulator driver (UCLASS_REGULATOR)

The sandbox PMIC has 12 significant registers and 4 as padding to 16 bytes,
which allows using 'i2c md' command with the default count (16).

The sandbox PMIC provides regulators:
- 2x BUCK
- 2x LDO

Each, with adjustable output:
- Enable state
- Voltage
- Current limit (LDO1/BUCK1 only)
- Operation mode (different for BUCK and LDO)

Each attribute has it's own register, beside the enable state, which depends
on operation mode.

The header file: sandbox_pmic.h includes PMIC's default register values,
which are set on i2c pmic emul driver's probe() method.

Signed-off-by: Przemyslaw Marczak <p.marczak@samsung.com>
Acked-by: Simon Glass <sjg@chromium.org>
Tested on sandbox:
Tested-by: Simon Glass <sjg@chromium.org>

7 files changed, 634 insertions, 1 deletions

diff --git a/drivers/power/pmic/Kconfig b/drivers/power/pmic/Kconfig
index d99d9e3a06..164f42143f 100644
--- a/drivers/power/pmic/Kconfig
+++ b/drivers/power/pmic/Kconfig
@@ -16,3 +16,28 @@ config DM_PMIC_MAX77686
 	---help---
 	This config enables implementation of driver-model pmic uclass features
 	for PMIC MAX77686. The driver implements read/write operations.
+
+config DM_PMIC_SANDBOX
+	bool "Enable Driver Model for emulated Sandbox PMIC "
+	depends on DM_PMIC
+	---help---
+	Enable the driver for Sandbox PMIC emulation. The emulated PMIC device
+	depends on two drivers:
+	- sandbox PMIC I/O driver - implements dm pmic operations
+	- sandbox PMIC i2c emul driver - emulates the PMIC's I2C transmission
+
+	A detailed information can be found in header: '<power/sandbox_pmic.h>'
+
+	The Sandbox PMIC info:
+	* I/O interface:
+	  - I2C chip address:       0x40
+	  - first register address: 0x0
+	  - register count:         0x10
+	* Adjustable outputs:
+	  - 2x LDO
+	  - 2x BUCK
+	  - Each, with a different operating conditions (header).
+	* Reset values:
+	  - set by i2c emul driver's probe() (defaults in header)
+
+	Driver binding info: doc/device-tree-bindings/pmic/sandbox.txt
diff --git a/drivers/power/pmic/Makefile b/drivers/power/pmic/Makefile
index 8cb993d0a7..ae86f041f3 100644
--- a/drivers/power/pmic/Makefile
+++ b/drivers/power/pmic/Makefile
@@ -6,12 +6,13 @@
 #
 
 obj-$(CONFIG_DM_PMIC) += pmic-uclass.o
+obj-$(CONFIG_DM_PMIC_MAX77686) += max77686.o
+obj-$(CONFIG_DM_PMIC_SANDBOX) += sandbox.o i2c_pmic_emul.o
 obj-$(CONFIG_POWER_LTC3676) += pmic_ltc3676.o
 obj-$(CONFIG_POWER_MAX8998) += pmic_max8998.o
 obj-$(CONFIG_POWER_MAX8997) += pmic_max8997.o
 obj-$(CONFIG_POWER_MUIC_MAX8997) += muic_max8997.o
 obj-$(CONFIG_POWER_MAX77686) += pmic_max77686.o
-obj-$(CONFIG_DM_PMIC_MAX77686) += max77686.o
 obj-$(CONFIG_POWER_PFUZE100) += pmic_pfuze100.o
 obj-$(CONFIG_POWER_TPS65090_I2C) += pmic_tps65090.o
 obj-$(CONFIG_POWER_TPS65090_EC) += pmic_tps65090_ec.o
diff --git a/drivers/power/pmic/i2c_pmic_emul.c b/drivers/power/pmic/i2c_pmic_emul.c
new file mode 100644
index 0000000000..aeab5c949a
--- /dev/null
+++ b/drivers/power/pmic/i2c_pmic_emul.c
@@ -0,0 +1,142 @@
+/*
+ *  Copyright (C) 2015 Samsung Electronics
+ *  Przemyslaw Marczak  <p.marczak@samsung.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <fdtdec.h>
+#include <errno.h>
+#include <dm.h>
+#include <i2c.h>
+#include <power/pmic.h>
+#include <power/sandbox_pmic.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+/**
+ * struct sandbox_i2c_pmic_plat_data - platform data for the PMIC
+ *
+ * @rw_reg: PMICs register of the chip I/O transaction
+ * @reg:    PMICs registers array
+ */
+struct sandbox_i2c_pmic_plat_data {
+	u8 rw_reg;
+	u8 reg[SANDBOX_PMIC_REG_COUNT];
+};
+
+static int sandbox_i2c_pmic_read_data(struct udevice *emul, uchar chip,
+				      uchar *buffer, int len)
+{
+	struct sandbox_i2c_pmic_plat_data *plat = dev_get_platdata(emul);
+
+	if (plat->rw_reg + len > SANDBOX_PMIC_REG_COUNT) {
+		error("Request exceeds PMIC register range! Max register: %#x",
+		      SANDBOX_PMIC_REG_COUNT);
+		return -EFAULT;
+	}
+
+	debug("Read PMIC: %#x at register: %#x count: %d\n",
+	      (unsigned)chip & 0xff, plat->rw_reg, len);
+
+	memcpy(buffer, &plat->reg[plat->rw_reg], len);
+
+	return 0;
+}
+
+static int sandbox_i2c_pmic_write_data(struct udevice *emul, uchar chip,
+				       uchar *buffer, int len,
+				       bool next_is_read)
+{
+	struct sandbox_i2c_pmic_plat_data *plat = dev_get_platdata(emul);
+
+	/* Probe only */
+	if (!len)
+		return 0;
+
+	/* Set PMIC register for I/O */
+	plat->rw_reg = *buffer;
+
+	debug("Write PMIC: %#x at register: %#x count: %d\n",
+	      (unsigned)chip & 0xff, plat->rw_reg, len);
+
+	/* For read operation, set (write) only chip reg */
+	if (next_is_read)
+		return 0;
+
+	buffer++;
+	len--;
+
+	if (plat->rw_reg + len > SANDBOX_PMIC_REG_COUNT) {
+		error("Request exceeds PMIC register range! Max register: %#x",
+		      SANDBOX_PMIC_REG_COUNT);
+	}
+
+	memcpy(&plat->reg[plat->rw_reg], buffer, len);
+
+	return 0;
+}
+
+static int sandbox_i2c_pmic_xfer(struct udevice *emul, struct i2c_msg *msg,
+				 int nmsgs)
+{
+	int ret = 0;
+
+	for (; nmsgs > 0; nmsgs--, msg++) {
+		bool next_is_read = nmsgs > 1 && (msg[1].flags & I2C_M_RD);
+		if (msg->flags & I2C_M_RD) {
+			ret = sandbox_i2c_pmic_read_data(emul, msg->addr,
+							 msg->buf, msg->len);
+		} else {
+			ret = sandbox_i2c_pmic_write_data(emul, msg->addr,
+							  msg->buf, msg->len,
+							  next_is_read);
+		}
+
+		if (ret)
+			break;
+	}
+
+	return ret;
+}
+
+static int sandbox_i2c_pmic_ofdata_to_platdata(struct udevice *emul)
+{
+	struct sandbox_i2c_pmic_plat_data *plat = dev_get_platdata(emul);
+	const u8 *reg_defaults;
+
+	debug("%s:%d Setting PMIC default registers\n", __func__, __LINE__);
+
+	reg_defaults = fdtdec_locate_byte_array(gd->fdt_blob, emul->of_offset,
+						"reg-defaults",
+						SANDBOX_PMIC_REG_COUNT);
+
+	if (!reg_defaults) {
+		error("Property \"reg-defaults\" not found for device: %s!",
+		      emul->name);
+		return -EINVAL;
+	}
+
+	memcpy(&plat->reg, reg_defaults, SANDBOX_PMIC_REG_COUNT);
+
+	return 0;
+}
+
+struct dm_i2c_ops sandbox_i2c_pmic_emul_ops = {
+	.xfer = sandbox_i2c_pmic_xfer,
+};
+
+static const struct udevice_id sandbox_i2c_pmic_ids[] = {
+	{ .compatible = "sandbox,i2c-pmic" },
+	{ }
+};
+
+U_BOOT_DRIVER(sandbox_i2c_pmic_emul) = {
+	.name		= "sandbox_i2c_pmic_emul",
+	.id		= UCLASS_I2C_EMUL,
+	.of_match	= sandbox_i2c_pmic_ids,
+	.ofdata_to_platdata = sandbox_i2c_pmic_ofdata_to_platdata,
+	.platdata_auto_alloc_size = sizeof(struct sandbox_i2c_pmic_plat_data),
+	.ops		= &sandbox_i2c_pmic_emul_ops,
+};
diff --git a/drivers/power/pmic/sandbox.c b/drivers/power/pmic/sandbox.c
new file mode 100644
index 0000000000..3e56acd5e2
--- /dev/null
+++ b/drivers/power/pmic/sandbox.c
@@ -0,0 +1,79 @@
+/*
+ *  Copyright (C) 2015 Samsung Electronics
+ *  Przemyslaw Marczak  <p.marczak@samsung.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#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/sandbox_pmic.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+static const struct pmic_child_info pmic_children_info[] = {
+	{ .prefix = SANDBOX_OF_LDO_PREFIX, .driver = SANDBOX_LDO_DRIVER },
+	{ .prefix = SANDBOX_OF_BUCK_PREFIX, .driver = SANDBOX_BUCK_DRIVER },
+	{ },
+};
+
+static int sandbox_pmic_reg_count(struct udevice *dev)
+{
+	return SANDBOX_PMIC_REG_COUNT;
+}
+
+static int sandbox_pmic_write(struct udevice *dev, uint reg,
+			      const uint8_t *buff, int len)
+{
+	if (dm_i2c_write(dev, reg, buff, len)) {
+		error("write error to device: %p register: %#x!", dev, reg);
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static int sandbox_pmic_read(struct udevice *dev, uint reg,
+			     uint8_t *buff, int len)
+{
+	if (dm_i2c_read(dev, reg, buff, len)) {
+		error("read error from device: %p register: %#x!", dev, reg);
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static int sandbox_pmic_bind(struct udevice *dev)
+{
+	if (!pmic_bind_children(dev, dev->of_offset, pmic_children_info))
+		error("%s:%d PMIC: %s - no child found!", __func__, __LINE__,
+							  dev->name);
+
+	/* Always return success for this device - allows for PMIC I/O */
+	return 0;
+}
+
+static struct dm_pmic_ops sandbox_pmic_ops = {
+	.reg_count = sandbox_pmic_reg_count,
+	.read = sandbox_pmic_read,
+	.write = sandbox_pmic_write,
+};
+
+static const struct udevice_id sandbox_pmic_ids[] = {
+	{ .compatible = "sandbox,pmic" },
+	{ }
+};
+
+U_BOOT_DRIVER(sandbox_pmic) = {
+	.name = "sandbox_pmic",
+	.id = UCLASS_PMIC,
+	.of_match = sandbox_pmic_ids,
+	.bind = sandbox_pmic_bind,
+	.ops = &sandbox_pmic_ops,
+};
diff --git a/drivers/power/regulator/Kconfig b/drivers/power/regulator/Kconfig
index fd3cf351b1..6289b83910 100644
--- a/drivers/power/regulator/Kconfig
+++ b/drivers/power/regulator/Kconfig
@@ -31,3 +31,33 @@ config DM_REGULATOR_FIXED
 	This config enables implementation of driver-model regulator uclass
 	features for fixed value regulators. The driver implements get/set api
 	for enable and get only for voltage value.
+
+config DM_REGULATOR_SANDBOX
+	bool "Enable Driver Model for Sandbox PMIC regulator"
+	depends on DM_REGULATOR && DM_PMIC_SANDBOX
+	---help---
+	Enable the regulator driver for emulated Sandbox PMIC.
+	The emulated PMIC device depends on two drivers:
+	- sandbox PMIC I/O driver - implements dm pmic operations
+	- sandbox PMIC regulator driver - implements dm regulator operations
+	- sandbox PMIC i2c emul driver - emulates the PMIC's I2C transmission
+
+	The regulator driver provides uclass operations for sandbox PMIC's
+	regulators. The driver implements get/set api for: voltage, current,
+	operation mode and enable state.
+	The driver supports LDO and BUCK regulators.
+
+	The Sandbox PMIC info:
+	* I/O interface:
+	  - I2C chip address:       0x40
+	  - first register address: 0x0
+	  - register count:         0x10
+	* Adjustable outputs:
+	  - 2x LDO
+	  - 2x BUCK
+	  - Each, with a different operating conditions (header).
+	* Reset values:
+	  - set by i2c emul driver's probe() (defaults in header)
+
+	A detailed information can be found in header: '<power/sandbox_pmic.h>'
+	Binding info: 'doc/device-tree-bindings/pmic/max77686.txt'
diff --git a/drivers/power/regulator/Makefile b/drivers/power/regulator/Makefile
index cc8326d78d..96aa624961 100644
--- a/drivers/power/regulator/Makefile
+++ b/drivers/power/regulator/Makefile
@@ -8,3 +8,4 @@
 obj-$(CONFIG_DM_REGULATOR) += regulator-uclass.o
 obj-$(CONFIG_DM_REGULATOR_MAX77686) += max77686.o
 obj-$(CONFIG_DM_REGULATOR_FIXED) += fixed.o
+obj-$(CONFIG_DM_REGULATOR_SANDBOX) += sandbox.o
diff --git a/drivers/power/regulator/sandbox.c b/drivers/power/regulator/sandbox.c
new file mode 100644
index 0000000000..2cca579a57
--- /dev/null
+++ b/drivers/power/regulator/sandbox.c
@@ -0,0 +1,355 @@
+/*
+ *  Copyright (C) 2015 Samsung Electronics
+ *  Przemyslaw Marczak  <p.marczak@samsung.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#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/sandbox_pmic.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+#define MODE(_id, _val, _name) [_id] = {  \
+	.id = _id,                \
+	.register_value = _val,   \
+	.name = _name,            \
+}
+
+#define RANGE(_min, _max, _step) { \
+	.min = _min,               \
+	.max = _max,               \
+	.step = _step,             \
+}
+
+/*
+ * struct output_range - helper structure type to define the range of output
+ * operating values (current/voltage), limited by the PMIC IC design.
+ *
+ * @min  - minimum value
+ * @max  - maximum value
+ * @step - step value
+*/
+struct output_range {
+	int min;
+	int max;
+	int step;
+};
+
+/* BUCK: 1,2 - voltage range */
+static struct output_range buck_voltage_range[] = {
+	RANGE(OUT_BUCK1_UV_MIN, OUT_BUCK1_UV_MAX, OUT_BUCK1_UV_STEP),
+	RANGE(OUT_BUCK2_UV_MIN, OUT_BUCK2_UV_MAX, OUT_BUCK2_UV_STEP),
+};
+
+/* BUCK: 1 - current range */
+static struct output_range buck_current_range[] = {
+	RANGE(OUT_BUCK1_UA_MIN, OUT_BUCK1_UA_MAX, OUT_BUCK1_UA_STEP),
+};
+
+/* BUCK operating modes */
+static struct dm_regulator_mode sandbox_buck_modes[] = {
+	MODE(BUCK_OM_OFF, OM2REG(BUCK_OM_OFF), "OFF"),
+	MODE(BUCK_OM_ON, OM2REG(BUCK_OM_ON), "ON"),
+	MODE(BUCK_OM_PWM, OM2REG(BUCK_OM_PWM), "PWM"),
+};
+
+/* LDO: 1,2 - voltage range */
+static struct output_range ldo_voltage_range[] = {
+	RANGE(OUT_LDO1_UV_MIN, OUT_LDO1_UV_MAX, OUT_LDO1_UV_STEP),
+	RANGE(OUT_LDO2_UV_MIN, OUT_LDO2_UV_MAX, OUT_LDO2_UV_STEP),
+};
+
+/* LDO: 1 - current range */
+static struct output_range ldo_current_range[] = {
+	RANGE(OUT_LDO1_UA_MIN, OUT_LDO1_UA_MAX, OUT_LDO1_UA_STEP),
+};
+
+/* LDO operating modes */
+static struct dm_regulator_mode sandbox_ldo_modes[] = {
+	MODE(LDO_OM_OFF, OM2REG(LDO_OM_OFF), "OFF"),
+	MODE(LDO_OM_ON, OM2REG(LDO_OM_ON), "ON"),
+	MODE(LDO_OM_SLEEP, OM2REG(LDO_OM_SLEEP), "SLEEP"),
+	MODE(LDO_OM_STANDBY, OM2REG(LDO_OM_STANDBY), "STANDBY"),
+};
+
+int out_get_value(struct udevice *dev, int output_count, int reg_type,
+		  struct output_range *range)
+{
+	uint8_t reg_val;
+	uint reg;
+	int ret;
+
+	if (dev->driver_data > output_count) {
+		error("Unknown regulator number: %lu for PMIC %s!",
+		      dev->driver_data, dev->name);
+		return -EINVAL;
+	}
+
+	reg = (dev->driver_data - 1) * OUT_REG_COUNT + reg_type;
+	ret = pmic_read(dev->parent, reg, &reg_val, 1);
+	if (ret) {
+		error("PMIC read failed: %d\n",  ret);
+		return ret;
+	}
+
+	ret =  REG2VAL(range[dev->driver_data - 1].min,
+		       range[dev->driver_data - 1].step,
+		       reg_val);
+
+	return ret;
+}
+
+static int out_set_value(struct udevice *dev, int output_count, int reg_type,
+			 struct output_range *range, int value)
+{
+	uint8_t reg_val;
+	uint reg;
+	int ret;
+	int max_value;
+
+	if (dev->driver_data > output_count) {
+		error("Unknown regulator number: %lu for PMIC %s!",
+		      dev->driver_data, dev->name);
+		return -EINVAL;
+	}
+
+	max_value = range[dev->driver_data - 1].max;
+	if (value > max_value) {
+		error("Wrong value for %s: %lu. Max is: %d.",
+		      dev->name, dev->driver_data, max_value);
+		return -EINVAL;
+	}
+
+	reg_val = VAL2REG(range[dev->driver_data - 1].min,
+			  range[dev->driver_data - 1].step,
+			  value);
+
+	reg = (dev->driver_data - 1) * OUT_REG_COUNT + reg_type;
+	ret = pmic_write(dev->parent, reg, &reg_val, 1);
+	if (ret) {
+		error("PMIC write failed: %d\n",  ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int out_get_mode(struct udevice *dev)
+{
+	struct dm_regulator_uclass_platdata *uc_pdata;
+	uint8_t reg_val;
+	uint reg;
+	int ret;
+	int i;
+
+	uc_pdata = dev_get_uclass_platdata(dev);
+
+	reg = (dev->driver_data - 1) * OUT_REG_COUNT + OUT_REG_OM;
+	ret = pmic_read(dev->parent, reg, &reg_val, 1);
+	if (ret) {
+		error("PMIC read failed: %d\n",  ret);
+		return ret;
+	}
+
+	for (i = 0; i < uc_pdata->mode_count; i++) {
+		if (reg_val == uc_pdata->mode[i].register_value)
+			return uc_pdata->mode[i].id;
+	}
+
+	error("Unknown operation mode for %s!", dev->name);
+	return -EINVAL;
+}
+
+static int out_set_mode(struct udevice *dev, int mode)
+{
+	struct dm_regulator_uclass_platdata *uc_pdata;
+	int reg_val = -1;
+	uint reg;
+	int ret;
+	int i;
+
+	uc_pdata = dev_get_uclass_platdata(dev);
+
+	if (mode >= uc_pdata->mode_count)
+		return -EINVAL;
+
+	for (i = 0; i < uc_pdata->mode_count; i++) {
+		if (mode == uc_pdata->mode[i].id) {
+			reg_val = uc_pdata->mode[i].register_value;
+			break;
+		}
+	}
+
+	if (reg_val == -1) {
+		error("Unknown operation mode for %s!", dev->name);
+		return -EINVAL;
+	}
+
+	reg = (dev->driver_data - 1) * OUT_REG_COUNT + OUT_REG_OM;
+	ret = pmic_write(dev->parent, reg, (uint8_t *)&reg_val, 1);
+	if (ret) {
+		error("PMIC write failed: %d\n",  ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int buck_get_voltage(struct udevice *dev)
+{
+	return out_get_value(dev, SANDBOX_BUCK_COUNT, OUT_REG_UV,
+			      buck_voltage_range);
+}
+
+static int buck_set_voltage(struct udevice *dev, int uV)
+{
+	return out_set_value(dev, SANDBOX_BUCK_COUNT, OUT_REG_UV,
+			      buck_voltage_range, uV);
+}
+
+static int buck_get_current(struct udevice *dev)
+{
+	/* BUCK2 - unsupported */
+	if (dev->driver_data == 2)
+		return -ENOSYS;
+
+	return out_get_value(dev, SANDBOX_BUCK_COUNT, OUT_REG_UA,
+			      buck_current_range);
+}
+
+static int buck_set_current(struct udevice *dev, int uA)
+{
+	/* BUCK2 - unsupported */
+	if (dev->driver_data == 2)
+		return -ENOSYS;
+
+	return out_set_value(dev, SANDBOX_BUCK_COUNT, OUT_REG_UA,
+			      buck_current_range, uA);
+}
+
+static bool buck_get_enable(struct udevice *dev)
+{
+	if (out_get_mode(dev) == BUCK_OM_OFF)
+		return false;
+
+	return true;
+}
+
+static int buck_set_enable(struct udevice *dev, bool enable)
+{
+	return out_set_mode(dev, enable ? BUCK_OM_ON : BUCK_OM_OFF);
+}
+
+static int sandbox_buck_probe(struct udevice *dev)
+{
+	struct dm_regulator_uclass_platdata *uc_pdata;
+
+	uc_pdata = dev_get_uclass_platdata(dev);
+
+	uc_pdata->type = REGULATOR_TYPE_BUCK;
+	uc_pdata->mode = sandbox_buck_modes;
+	uc_pdata->mode_count = ARRAY_SIZE(sandbox_buck_modes);
+
+	return 0;
+}
+
+static const struct dm_regulator_ops sandbox_buck_ops = {
+	.get_value   = buck_get_voltage,
+	.set_value   = buck_set_voltage,
+	.get_current = buck_get_current,
+	.set_current = buck_set_current,
+	.get_enable  = buck_get_enable,
+	.set_enable  = buck_set_enable,
+	.get_mode    = out_get_mode,
+	.set_mode    = out_set_mode,
+};
+
+U_BOOT_DRIVER(sandbox_buck) = {
+	.name = SANDBOX_BUCK_DRIVER,
+	.id = UCLASS_REGULATOR,
+	.ops = &sandbox_buck_ops,
+	.probe = sandbox_buck_probe,
+};
+
+static int ldo_get_voltage(struct udevice *dev)
+{
+	return out_get_value(dev, SANDBOX_LDO_COUNT, OUT_REG_UV,
+			     ldo_voltage_range);
+}
+
+static int ldo_set_voltage(struct udevice *dev, int uV)
+{
+	return out_set_value(dev, SANDBOX_LDO_COUNT, OUT_REG_UV,
+			     ldo_voltage_range, uV);
+}
+
+static int ldo_get_current(struct udevice *dev)
+{
+	/* LDO2 - unsupported */
+	if (dev->driver_data == 2)
+		return -ENOSYS;
+
+	return out_get_value(dev, SANDBOX_LDO_COUNT, OUT_REG_UA,
+			     ldo_current_range);
+}
+
+static int ldo_set_current(struct udevice *dev, int uA)
+{
+	/* LDO2 - unsupported */
+	if (dev->driver_data == 2)
+		return -ENOSYS;
+
+	return out_set_value(dev, SANDBOX_LDO_COUNT, OUT_REG_UA,
+			     ldo_current_range, uA);
+}
+
+static bool ldo_get_enable(struct udevice *dev)
+{
+	if (out_get_mode(dev) == LDO_OM_OFF)
+		return false;
+
+	return true;
+}
+
+static int ldo_set_enable(struct udevice *dev, bool enable)
+{
+	return out_set_mode(dev, enable ? LDO_OM_ON : LDO_OM_OFF);
+}
+
+static int sandbox_ldo_probe(struct udevice *dev)
+{
+	struct dm_regulator_uclass_platdata *uc_pdata;
+
+	uc_pdata = dev_get_uclass_platdata(dev);
+
+	uc_pdata->type = REGULATOR_TYPE_LDO;
+	uc_pdata->mode = sandbox_ldo_modes;
+	uc_pdata->mode_count = ARRAY_SIZE(sandbox_ldo_modes);
+
+	return 0;
+}
+
+static const struct dm_regulator_ops sandbox_ldo_ops = {
+	.get_value   = ldo_get_voltage,
+	.set_value   = ldo_set_voltage,
+	.get_current = ldo_get_current,
+	.set_current = ldo_set_current,
+	.get_enable  = ldo_get_enable,
+	.set_enable  = ldo_set_enable,
+	.get_mode    = out_get_mode,
+	.set_mode    = out_set_mode,
+};
+
+U_BOOT_DRIVER(sandbox_ldo) = {
+	.name = SANDBOX_LDO_DRIVER,
+	.id = UCLASS_REGULATOR,
+	.ops = &sandbox_ldo_ops,
+	.probe = sandbox_ldo_probe,
+};