[PATCH v2 2/2] regulator: rt6245: Add support for Richtek RT6245

From: cy_huang
Date: Thu May 27 2021 - 01:14:29 EST


From: ChiYuan Huang <cy_huang@xxxxxxxxxxx>

Richtek RT6245 is a high-performance, synchronous step-down converter
that can deliver up to 14A output current with an input supply voltage
range of 4.5V to 17V.

Signed-off-by: ChiYuan Huang <cy_huang@xxxxxxxxxxx>
---
since v2
- Use hweight8 to fix x86 __sw_hweight8 undefined.
---
drivers/regulator/Kconfig | 9 ++
drivers/regulator/Makefile | 1 +
drivers/regulator/rt6245-regulator.c | 260 +++++++++++++++++++++++++++++++++++
3 files changed, 270 insertions(+)
create mode 100644 drivers/regulator/rt6245-regulator.c

diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig
index 9d84d92..cdec434 100644
--- a/drivers/regulator/Kconfig
+++ b/drivers/regulator/Kconfig
@@ -1030,6 +1030,15 @@ config REGULATOR_RT5033
RT5033 PMIC. The device supports multiple regulators like
current source, LDO and Buck.

+config REGULATOR_RT6245
+ tristate "Richtek RT6245 voltage regulator"
+ depends on I2C
+ select REGMAP_I2C
+ help
+ This adds supprot for Richtek RT6245 voltage regulator.
+ It can support up to 14A output current and adjustable output voltage
+ from 0.4375V to 1.3875V, per step 12.5mV.
+
config REGULATOR_RTMV20
tristate "RTMV20 Laser Diode Regulator"
depends on I2C
diff --git a/drivers/regulator/Makefile b/drivers/regulator/Makefile
index 580b015..69668bf 100644
--- a/drivers/regulator/Makefile
+++ b/drivers/regulator/Makefile
@@ -124,6 +124,7 @@ obj-$(CONFIG_REGULATOR_ROHM) += rohm-regulator.o
obj-$(CONFIG_REGULATOR_RT4801) += rt4801-regulator.o
obj-$(CONFIG_REGULATOR_RT4831) += rt4831-regulator.o
obj-$(CONFIG_REGULATOR_RT5033) += rt5033-regulator.o
+obj-$(CONFIG_REGULATOR_RT6245) += rt6245-regulator.o
obj-$(CONFIG_REGULATOR_RTMV20) += rtmv20-regulator.o
obj-$(CONFIG_REGULATOR_S2MPA01) += s2mpa01.o
obj-$(CONFIG_REGULATOR_S2MPS11) += s2mps11.o
diff --git a/drivers/regulator/rt6245-regulator.c b/drivers/regulator/rt6245-regulator.c
new file mode 100644
index 00000000..e4032b0
--- /dev/null
+++ b/drivers/regulator/rt6245-regulator.c
@@ -0,0 +1,260 @@
+// SPDX-License-Identifier: GPL-2.0+
+
+#include <linux/bitops.h>
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/regulator/driver.h>
+#include <linux/regulator/of_regulator.h>
+
+#define RT6245_VIRT_OCLIMIT 0x00
+#define RT6245_VIRT_OTLEVEL 0x01
+#define RT6245_VIRT_PGDLYTIME 0x02
+#define RT6245_VIRT_SLEWRATE 0x03
+#define RT6245_VIRT_SWFREQ 0x04
+#define RT6245_VIRT_VOUT 0x05
+
+#define RT6245_VOUT_MASK GENMASK(6, 0)
+#define RT6245_CHKSUM_MASK BIT(7)
+#define RT6245_CODE_MASK GENMASK(6, 0)
+
+/* HW Enable + Soft start time */
+#define RT6245_ENTIME_IN_US 5000
+
+#define RT6245_RAMPT_UNIT_0P1UV 15625
+#define RT6245_RAMPT_MAXUV 12500
+#define RT6245_RAMPT_BASESEL 1
+
+#define RT6245_VOUT_MINUV 437500
+#define RT6245_VOUT_MAXUV 1387500
+#define RT6245_VOUT_STEPUV 12500
+#define RT6245_NUM_VOUT ((RT6245_VOUT_MAXUV - RT6245_VOUT_MINUV) / RT6245_VOUT_STEPUV + 1)
+
+struct rt6245_priv {
+ struct gpio_desc *enable_gpio;
+ bool enable_state;
+};
+
+static int rt6245_set_ramp_delay(struct regulator_dev *rdev, int ramp_delay)
+{
+ struct regmap *regmap = rdev_get_regmap(rdev);
+ unsigned int ramp_time_scale;
+
+ if (ramp_delay == 0 || ramp_delay > RT6245_RAMPT_MAXUV) {
+ dev_warn(&rdev->dev, "Not in ramp time range %d, set to fastest\n", ramp_delay);
+ ramp_delay = RT6245_RAMPT_MAXUV;
+ }
+
+ /* ramp_time = max_ramp_time / ramp_time_scale, scale from 1 to 8 */
+ ramp_delay = max(ramp_delay * 10, RT6245_RAMPT_UNIT_0P1UV);
+ ramp_time_scale = (RT6245_RAMPT_MAXUV * 10) / ramp_delay;
+ ramp_time_scale -= RT6245_RAMPT_BASESEL;
+
+ return regmap_write(regmap, RT6245_VIRT_SLEWRATE, ramp_time_scale);
+}
+
+static int rt6245_enable(struct regulator_dev *rdev)
+{
+ struct rt6245_priv *priv = rdev_get_drvdata(rdev);
+ struct regmap *regmap = rdev_get_regmap(rdev);
+
+ if (!priv->enable_gpio)
+ return 0;
+
+ priv->enable_state = true;
+ gpiod_direction_output(priv->enable_gpio, 1);
+ usleep_range(RT6245_ENTIME_IN_US, RT6245_ENTIME_IN_US + 1000);
+
+ regcache_cache_only(regmap, false);
+ return regcache_sync(regmap);
+}
+
+static int rt6245_disable(struct regulator_dev *rdev)
+{
+ struct rt6245_priv *priv = rdev_get_drvdata(rdev);
+ struct regmap *regmap = rdev_get_regmap(rdev);
+
+ if (!priv->enable_gpio)
+ return -ENOTSUPP;
+
+ priv->enable_state = false;
+ gpiod_direction_output(priv->enable_gpio, 0);
+
+ regcache_cache_only(regmap, true);
+ regcache_mark_dirty(regmap);
+
+ return 0;
+}
+
+static int rt6245_is_enabled(struct regulator_dev *rdev)
+{
+ struct rt6245_priv *priv = rdev_get_drvdata(rdev);
+
+ return priv->enable_state ? 1 : 0;
+}
+
+static const struct regulator_ops rt6245_regulator_ops = {
+ .list_voltage = regulator_list_voltage_linear,
+ .set_voltage_sel = regulator_set_voltage_sel_regmap,
+ .get_voltage_sel = regulator_get_voltage_sel_regmap,
+ .set_ramp_delay = rt6245_set_ramp_delay,
+ .enable = rt6245_enable,
+ .disable = rt6245_disable,
+ .is_enabled = rt6245_is_enabled,
+};
+
+static const struct regulator_desc rt6245_regulator_desc = {
+ .name = "rt6245-regulator",
+ .ops = &rt6245_regulator_ops,
+ .type = REGULATOR_VOLTAGE,
+ .min_uV = RT6245_VOUT_MINUV,
+ .uV_step = RT6245_VOUT_STEPUV,
+ .n_voltages = RT6245_NUM_VOUT,
+ .owner = THIS_MODULE,
+ .vsel_reg = RT6245_VIRT_VOUT,
+ .vsel_mask = RT6245_VOUT_MASK,
+};
+
+static int rt6245_init_device_properties(struct device *dev)
+{
+ struct {
+ const char *name;
+ unsigned int reg;
+ } rt6245_props[] = {
+ { "richtek,oc-level-select", RT6245_VIRT_OCLIMIT },
+ { "richtek,ot-level-select", RT6245_VIRT_OTLEVEL },
+ { "richtek,pgdly-time-select", RT6245_VIRT_PGDLYTIME },
+ { "richtek,switch-freq-select", RT6245_VIRT_SWFREQ }
+ };
+ struct regmap *regmap = dev_get_regmap(dev, NULL);
+ u8 propval;
+ int i, ret;
+
+ for (i = 0; i < ARRAY_SIZE(rt6245_props); i++) {
+ ret = device_property_read_u8(dev, rt6245_props[i].name, &propval);
+ if (ret)
+ continue;
+
+ ret = regmap_write(regmap, rt6245_props[i].reg, propval);
+ if (ret) {
+ dev_err(dev, "Fail to apply [%s:%d]\n", rt6245_props[i].name, propval);
+ return ret;
+ }
+ }
+
+ return 0;
+}
+
+static int rt6245_reg_write(void *context, unsigned int reg, unsigned int val)
+{
+ struct i2c_client *i2c = context;
+ const u8 func_base[] = { 0x6F, 0x73, 0x78, 0x61, 0x7C, 0 };
+ unsigned int code, bit_count;
+
+ code = func_base[reg];
+ code += val;
+
+ /* xor checksum for bit 6 to 0 */
+ bit_count = hweight8(code & RT6245_CODE_MASK);
+ if (bit_count % 2)
+ code |= RT6245_CHKSUM_MASK;
+ else
+ code &= ~RT6245_CHKSUM_MASK;
+
+ return i2c_smbus_write_byte(i2c, code);
+}
+
+static const struct reg_default rt6245_reg_defaults[] = {
+ /* Default over current 14A */
+ { RT6245_VIRT_OCLIMIT, 2 },
+ /* Default over temperature 150'c */
+ { RT6245_VIRT_OTLEVEL, 0 },
+ /* Default power good delay time 10us */
+ { RT6245_VIRT_PGDLYTIME, 1 },
+ /* Default slewrate 12.5mV/uS */
+ { RT6245_VIRT_SLEWRATE, 0 },
+ /* Default switch frequency 800KHz */
+ { RT6245_VIRT_SWFREQ, 1 },
+ /* Default voltage 750mV */
+ { RT6245_VIRT_VOUT, 0x19 }
+};
+
+static const struct regmap_config rt6245_regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 8,
+ .max_register = RT6245_VIRT_VOUT,
+ .cache_type = REGCACHE_FLAT,
+ .reg_defaults = rt6245_reg_defaults,
+ .num_reg_defaults = ARRAY_SIZE(rt6245_reg_defaults),
+ .reg_write = rt6245_reg_write,
+};
+
+static int rt6245_probe(struct i2c_client *i2c)
+{
+ struct rt6245_priv *priv;
+ struct regmap *regmap;
+ struct regulator_config regulator_cfg = {};
+ struct regulator_dev *rdev;
+ int ret;
+
+ priv = devm_kzalloc(&i2c->dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->enable_state = true;
+
+ priv->enable_gpio = devm_gpiod_get_optional(&i2c->dev, "enable", GPIOD_OUT_HIGH);
+ if (IS_ERR(priv->enable_gpio)) {
+ dev_err(&i2c->dev, "Failed to get 'enable' gpio\n");
+ return PTR_ERR(priv->enable_gpio);
+ }
+ usleep_range(RT6245_ENTIME_IN_US, RT6245_ENTIME_IN_US + 1000);
+
+ regmap = devm_regmap_init(&i2c->dev, NULL, i2c, &rt6245_regmap_config);
+ if (IS_ERR(regmap)) {
+ dev_err(&i2c->dev, "Failed to initialize the regmap\n");
+ return PTR_ERR(regmap);
+ }
+
+ ret = rt6245_init_device_properties(&i2c->dev);
+ if (ret) {
+ dev_err(&i2c->dev, "Failed to initialize device properties\n");
+ return ret;
+ }
+
+ regulator_cfg.dev = &i2c->dev;
+ regulator_cfg.of_node = i2c->dev.of_node;
+ regulator_cfg.regmap = regmap;
+ regulator_cfg.driver_data = priv;
+ regulator_cfg.init_data = of_get_regulator_init_data(&i2c->dev, i2c->dev.of_node,
+ &rt6245_regulator_desc);
+ rdev = devm_regulator_register(&i2c->dev, &rt6245_regulator_desc, &regulator_cfg);
+ if (IS_ERR(rdev)) {
+ dev_err(&i2c->dev, "Failed to register regulator\n");
+ return PTR_ERR(rdev);
+ }
+
+ return 0;
+}
+
+static const struct of_device_id __maybe_unused rt6245_of_match_table[] = {
+ { .compatible = "richtek,rt6245", },
+ {}
+};
+MODULE_DEVICE_TABLE(of, rt6245_of_match_table);
+
+static struct i2c_driver rt6245_driver = {
+ .driver = {
+ .name = "rt6245",
+ .of_match_table = rt6245_of_match_table,
+ },
+ .probe_new = rt6245_probe,
+};
+module_i2c_driver(rt6245_driver);
+
+MODULE_AUTHOR("ChiYuan Hwang <cy_huang@xxxxxxxxxxx>");
+MODULE_DESCRIPTION("Richtek RT6245 Regulator Driver");
+MODULE_LICENSE("GPL v2");
--
2.7.4