[PATCH] regulator: Add support for RT4801 Display Bias regulator driver
From: cy_huang
Date: Fri Aug 14 2020 - 01:59:54 EST
From: ChiYuan Huang <cy_huang@xxxxxxxxxxx>
Adds support for the RT4801 DSV. It has two regulators (DSVP/DSVN) with an I2C
interface. DSVP/DSVN can provide the display panel module for the positive/negative
voltage range from (+/-)4V to (+/-)6V.
---
.../regulator/richtek,rt4801-regulator.yaml | 80 ++++++++
drivers/regulator/Kconfig | 7 +
drivers/regulator/Makefile | 1 +
drivers/regulator/rt4801-regulator.c | 223 +++++++++++++++++++++
4 files changed, 311 insertions(+)
create mode 100644 Documentation/devicetree/bindings/regulator/richtek,rt4801-regulator.yaml
create mode 100644 drivers/regulator/rt4801-regulator.c
diff --git a/Documentation/devicetree/bindings/regulator/richtek,rt4801-regulator.yaml b/Documentation/devicetree/bindings/regulator/richtek,rt4801-regulator.yaml
new file mode 100644
index 00000000..28d30e2
--- /dev/null
+++ b/Documentation/devicetree/bindings/regulator/richtek,rt4801-regulator.yaml
@@ -0,0 +1,80 @@
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/regulator/richtek,rt4801-regulator.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Richtek RT4801 Display Bias regulators
+
+maintainers:
+ - ChiYuan Huang <cy_huang@xxxxxxxxxxx>
+
+description: |
+ Regulator nodes should be named to DSVP and DSVN. The
+ definition for each of these nodes is defined using the standard
+ binding for regulators at
+ Documentation/devicetree/bindings/regulator/regulator.txt.
+ Datasheet is available at
+ https://www.richtek.com/assets/product_file/RT4801H/DS4801H-00.pdf
+
+#The valid names for RT4801 regulator nodes are:
+#DSVP, DSVN
+
+properties:
+ compatible:
+ enum:
+ - richtek,rt4801
+
+ reg:
+ maxItems: 1
+
+ enable-gpios:
+ description: GPIOs to use to enable DSVP/DSVN regulator.
+ The first one is ENP to enable DSVP, and second one is ENM to enable DSVN.
+ Number of GPIO in the array list could be 1 or 2.
+ If only one gpio is specified, only one gpio used to control ENP/ENM.
+ Else both are spefied, DSVP/DSVN could be controlled individually.
+ Othersie, this property not specified. treat both as always-on regulator.
+ minItems: 1
+ maxItems: 2
+
+patternProperties:
+ "^DSV(P|N)$":
+ type: object
+ $ref: regulator.yaml#
+ description:
+ Properties for single display bias regulator.
+
+required:
+ - compatible
+ - reg
+
+additionalProperties:
+ - enable-gpios
+
+examples:
+ - |
+ i2c {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ rt4801@73 {
+ compatible = "richtek,rt4801";
+ reg = <0x73>;
+ enable-gpios = <&gpio26 2 0>, <&gpio26 3 0>;
+
+ dsvp: DSVP {
+ regulator-name = "rt4801,dsvp";
+ regulator-min-microvolt = <4000000>;
+ regulator-max-microvolt = <6000000>;
+ regulator-boot-on;
+ };
+ dsvn: DSVN {
+ regulator-name = "rt4801,dsvn";
+ regulator-min-microvolt = <4000000>;
+ regulator-max-microvolt = <6000000>;
+ regulator-boot-on;
+ };
+
+ };
+ };
diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig
index de17ef7..2786f11 100644
--- a/drivers/regulator/Kconfig
+++ b/drivers/regulator/Kconfig
@@ -894,6 +894,13 @@ config REGULATOR_RN5T618
config REGULATOR_ROHM
tristate
+config REGULATOR_RT4801
+ tristate "Richtek RT4801 Regulators"
+ depends on I2C
+ help
+ This adds support for voltage regulators in Richtek RT4801 Display Bias IC.
+ The device supports two regulators (DSVP/DSVN).
+
config REGULATOR_RT5033
tristate "Richtek RT5033 Regulators"
depends on MFD_RT5033
diff --git a/drivers/regulator/Makefile b/drivers/regulator/Makefile
index d8d3ecf..d091e52d 100644
--- a/drivers/regulator/Makefile
+++ b/drivers/regulator/Makefile
@@ -111,6 +111,7 @@ obj-$(CONFIG_REGULATOR_RC5T583) += rc5t583-regulator.o
obj-$(CONFIG_REGULATOR_RK808) += rk808-regulator.o
obj-$(CONFIG_REGULATOR_RN5T618) += rn5t618-regulator.o
obj-$(CONFIG_REGULATOR_ROHM) += rohm-regulator.o
+obj-$(CONFIG_REGULATOR_RT4801) += rt4801-regulator.o
obj-$(CONFIG_REGULATOR_RT5033) += rt5033-regulator.o
obj-$(CONFIG_REGULATOR_S2MPA01) += s2mpa01.o
obj-$(CONFIG_REGULATOR_S2MPS11) += s2mps11.o
diff --git a/drivers/regulator/rt4801-regulator.c b/drivers/regulator/rt4801-regulator.c
new file mode 100644
index 00000000..0ddc670
--- /dev/null
+++ b/drivers/regulator/rt4801-regulator.c
@@ -0,0 +1,223 @@
+// SPDX-License-Identifier: GPL-2.0+
+
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/regmap.h>
+#include <linux/regulator/driver.h>
+
+#define RT4801_REG_VOP 0x00
+#define RT4801_REG_VON 0x01
+#define RT4801_REG_APPS 0x03
+
+#define VOUT_MASK 0x1F
+
+#define MIN_UV 4000000
+#define STEP_UV 100000
+#define MAX_UV 6000000
+#define N_VOLTAGES ((MAX_UV - MIN_UV) / STEP_UV + 1)
+
+#define DSV_OUT_POS 0
+#define DSV_OUT_NEG 1
+#define DSV_OUT_MAX 2
+
+#define DSVP_ENABLE BIT(0)
+#define DSVN_ENABLE BIT(1)
+#define DSVALL_ENABLE (DSVP_ENABLE | DSVN_ENABLE)
+
+struct rt4801_priv {
+ struct device *dev;
+ struct gpio_descs *enable_gpios;
+ unsigned int enable_flag;
+ unsigned int volt_sel[DSV_OUT_MAX];
+};
+
+static int rt4801_set_voltage_sel(struct regulator_dev *rdev, unsigned int selector)
+{
+ struct rt4801_priv *priv = rdev_get_drvdata(rdev);
+ int id = rdev_get_id(rdev), ret;
+
+ if (priv->enable_flag & BIT(id)) {
+ ret = regulator_set_voltage_sel_regmap(rdev, selector);
+ if (ret)
+ return ret;
+ }
+
+ priv->volt_sel[id] = selector;
+ return 0;
+}
+
+static int rt4801_get_voltage_sel(struct regulator_dev *rdev)
+{
+ struct rt4801_priv *priv = rdev_get_drvdata(rdev);
+ int id = rdev_get_id(rdev);
+
+ if (priv->enable_flag & BIT(id))
+ return regulator_get_voltage_sel_regmap(rdev);
+
+ return priv->volt_sel[id];
+}
+
+static int rt4801_enable(struct regulator_dev *rdev)
+{
+ struct rt4801_priv *priv = rdev_get_drvdata(rdev);
+ struct gpio_descs *gpios = priv->enable_gpios;
+ int id = rdev_get_id(rdev), ret;
+
+ if (gpios->ndescs <= id) {
+ dev_warn(&rdev->dev, "no dedicated gpio can control\n");
+ goto bypass_gpio;
+ }
+
+ gpiod_set_value(gpios->desc[id], 1);
+
+bypass_gpio:
+ ret = regmap_write(rdev->regmap, rdev->desc->vsel_reg, priv->volt_sel[id]);
+ if (ret)
+ return ret;
+
+ priv->enable_flag |= BIT(id);
+ return 0;
+}
+
+static int rt4801_disable(struct regulator_dev *rdev)
+{
+ struct rt4801_priv *priv = rdev_get_drvdata(rdev);
+ struct gpio_descs *gpios = priv->enable_gpios;
+ int id = rdev_get_id(rdev);
+
+ if (gpios->ndescs <= id) {
+ dev_warn(&rdev->dev, "no dedicated gpio can control\n");
+ goto bypass_gpio;
+ }
+
+ gpiod_set_value(gpios->desc[id], 0);
+
+bypass_gpio:
+ priv->enable_flag &= ~BIT(id);
+ return 0;
+}
+
+static int rt4801_is_enabled(struct regulator_dev *rdev)
+{
+ struct rt4801_priv *priv = rdev_get_drvdata(rdev);
+ int id = rdev_get_id(rdev);
+
+ return !!(priv->enable_flag & BIT(id));
+}
+
+static const struct regulator_ops rt4801_regulator_ops = {
+ .list_voltage = regulator_list_voltage_linear,
+ .set_voltage_sel = rt4801_set_voltage_sel,
+ .get_voltage_sel = rt4801_get_voltage_sel,
+ .enable = rt4801_enable,
+ .disable = rt4801_disable,
+ .is_enabled = rt4801_is_enabled,
+};
+
+static const struct regulator_desc rt4801_regulator_descs[] = {
+ {
+ .name = "DSVP",
+ .ops = &rt4801_regulator_ops,
+ .of_match = of_match_ptr("DSVP"),
+ .type = REGULATOR_VOLTAGE,
+ .id = DSV_OUT_POS,
+ .min_uV = MIN_UV,
+ .uV_step = STEP_UV,
+ .n_voltages = N_VOLTAGES,
+ .owner = THIS_MODULE,
+ .vsel_reg = RT4801_REG_VOP,
+ .vsel_mask = VOUT_MASK,
+ },
+ {
+ .name = "DSVN",
+ .ops = &rt4801_regulator_ops,
+ .of_match = of_match_ptr("DSVN"),
+ .type = REGULATOR_VOLTAGE,
+ .id = DSV_OUT_NEG,
+ .min_uV = MIN_UV,
+ .uV_step = STEP_UV,
+ .n_voltages = N_VOLTAGES,
+ .owner = THIS_MODULE,
+ .vsel_reg = RT4801_REG_VON,
+ .vsel_mask = VOUT_MASK,
+ },
+};
+
+static const struct regmap_config rt4801_regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 8,
+ .max_register = RT4801_REG_APPS,
+};
+
+static int rt4801_probe(struct i2c_client *i2c)
+{
+ struct rt4801_priv *priv;
+ struct regmap *regmap;
+ int i;
+
+ priv = devm_kzalloc(&i2c->dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->dev = &i2c->dev;
+ /* bootloader will on, driver only reconfigure enable to all output high */
+ priv->enable_flag = DSVALL_ENABLE;
+
+ regmap = devm_regmap_init_i2c(i2c, &rt4801_regmap_config);
+ if (IS_ERR(regmap)) {
+ dev_err(&i2c->dev, "Failed to init regmap\n");
+ return PTR_ERR(regmap);
+ }
+
+ priv->enable_gpios = devm_gpiod_get_array_optional(&i2c->dev, "enable", GPIOD_OUT_HIGH);
+ if (IS_ERR(priv->enable_gpios)) {
+ dev_err(&i2c->dev, "Failed to get gpios\n");
+ return PTR_ERR(priv->enable_gpios);
+ }
+
+ for (i = 0; i < DSV_OUT_MAX; i++) {
+ const struct regulator_desc *desc = rt4801_regulator_descs + i;
+ struct regulator_config config = { .dev = &i2c->dev, .driver_data = priv,
+ .regmap = regmap, };
+ struct regulator_dev *rdev;
+ unsigned int val;
+ int ret;
+
+ /* initialize volt_sel variable */
+ ret = regmap_read(regmap, desc->vsel_reg, &val);
+ if (ret)
+ return ret;
+
+ priv->volt_sel[i] = val & desc->vsel_mask;
+
+ rdev = devm_regulator_register(&i2c->dev, desc, &config);
+ if (IS_ERR(rdev)) {
+ dev_err(&i2c->dev, "Failed to register [%d] regulator\n", i);
+ return PTR_ERR(rdev);
+ }
+ }
+
+ return 0;
+}
+
+static const struct of_device_id rt4801_of_id[] = {
+ { .compatible = "richtek,rt4801", },
+ { },
+};
+MODULE_DEVICE_TABLE(of, rt4801_of_id);
+
+static struct i2c_driver rt4801_driver = {
+ .driver = {
+ .name = "rt4801",
+ .of_match_table = of_match_ptr(rt4801_of_id),
+ },
+ .probe_new = rt4801_probe,
+};
+module_i2c_driver(rt4801_driver);
+
+MODULE_AUTHOR("ChiYuan Hwang <cy_huang@xxxxxxxxxxx>");
+MODULE_DESCRIPTION("Richtek RT4801 Display Bias Driver");
+MODULE_LICENSE("GPL v2");
--
2.7.4