[PATCH V3 3/4] regulator: Add a regulator driver for the PM8008 PMIC

From: Satya Priya
Date: Thu Oct 28 2021 - 11:16:08 EST

Qualcomm Technologies, Inc. PM8008 is an I2C controlled PMIC
containing 7 LDO regulators. Add a PM8008 regulator driver to
support PMIC regulator management via the regulator framework.

Signed-off-by: Satya Priya <quic_c_skakit@xxxxxxxxxxx>
---
Changes in V2:
- As per Mark's comments
- Using regmap helpers for regulator enable/disable and is_enabled APIs
- Changed pr_err to dev_err wherever possible.
- Removed init_voltage property as it is not used.
- Removed if check for registering LDOs
- Other minor changes.

Changes in V3:
- As per Stephen's comments,
- Removed unused includes
- Removed PM8008_MAX_LDO macro.
- Removed pm8008_read/write APIs, using regmap_bulk_read/write APIs
- Using le16_to_cpu/cpu_to_le16 APIs in pm8008_regulator_get/set_voltage
- Consolidated all probe related functions into single probe function.
- Added of_parse_cb call back and removed regulator-name matching loop.
- Fixed other minor nits.

drivers/regulator/Kconfig | 9 +
drivers/regulator/Makefile | 1 +
drivers/regulator/qcom-pm8008-regulator.c | 269 ++++++++++++++++++++++++++++++
3 files changed, 279 insertions(+)
create mode 100644 drivers/regulator/qcom-pm8008-regulator.c

diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig
index 6be9b1c..61e3e98 100644
--- a/drivers/regulator/Kconfig
+++ b/drivers/regulator/Kconfig
@@ -916,6 +916,15 @@ config REGULATOR_PWM
This driver supports PWM controlled voltage regulators. PWM
duty cycle can increase or decrease the voltage.

+config REGULATOR_QCOM_PM8008
+ tristate "Qualcomm Technologies, Inc. PM8008 PMIC regulators"
+ depends on MFD_QCOM_PM8008
+ help
+ Select this option to get support for the voltage regulators
+ of Qualcomm Technologies, Inc. PM8008 PMIC chip. PM8008 has 7 LDO
+ regulators. This driver provides support for basic operations like
+ set/get voltage and enable/disable.
+
config REGULATOR_QCOM_RPM
tristate "Qualcomm RPM regulator driver"
depends on MFD_QCOM_RPM
diff --git a/drivers/regulator/Makefile b/drivers/regulator/Makefile
index b07d2a2..4fac16b6 100644
--- a/drivers/regulator/Makefile
+++ b/drivers/regulator/Makefile
@@ -100,6 +100,7 @@ obj-$(CONFIG_REGULATOR_MT6380) += mt6380-regulator.o
obj-$(CONFIG_REGULATOR_MT6397) += mt6397-regulator.o
obj-$(CONFIG_REGULATOR_MTK_DVFSRC) += mtk-dvfsrc-regulator.o
obj-$(CONFIG_REGULATOR_QCOM_LABIBB) += qcom-labibb-regulator.o
+obj-$(CONFIG_REGULATOR_QCOM_PM8008) += qcom-pm8008-regulator.o
obj-$(CONFIG_REGULATOR_QCOM_RPM) += qcom_rpm-regulator.o
obj-$(CONFIG_REGULATOR_QCOM_RPMH) += qcom-rpmh-regulator.o
obj-$(CONFIG_REGULATOR_QCOM_SMD_RPM) += qcom_smd-regulator.o
diff --git a/drivers/regulator/qcom-pm8008-regulator.c b/drivers/regulator/qcom-pm8008-regulator.c
new file mode 100644
index 0000000..74ba682
--- /dev/null
+++ b/drivers/regulator/qcom-pm8008-regulator.c
@@ -0,0 +1,269 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2021, The Linux Foundation. All rights reserved. */
+
+#include <linux/device.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/regulator/driver.h>
+#include <linux/regulator/machine.h>
+#include <linux/regulator/of_regulator.h>
+
+#define STARTUP_DELAY_USEC 20
+#define VSET_STEP_MV 8
+#define VSET_STEP_UV (VSET_STEP_MV * 1000)
+
+#define LDO_ENABLE_REG(base) (base + 0x46)
+#define ENABLE_BIT BIT(7)
+
+#define LDO_STATUS1_REG(base) (base + 0x08)
+#define VREG_READY_BIT BIT(7)
+
+#define LDO_VSET_LB_REG(base) (base + 0x40)
+
+#define LDO_STEPPER_CTL_REG(base) (base + 0x3b)
+#define DEFAULT_VOLTAGE_STEPPER_RATE 38400
+#define STEP_RATE_MASK GENMASK(1, 0)
+
+struct regulator_data {
+ const char *name;
+ const char *supply_name;
+ int min_uv;
+ int max_uv;
+ int min_dropout_uv;
+};
+
+struct pm8008_regulator {
+ struct device *dev;
+ struct regmap *regmap;
+ struct regulator_desc rdesc;
+ struct regulator_dev *rdev;
+ struct device_node *of_node;
+ u16 base;
+ int step_rate;
+};
+
+static const struct regulator_data reg_data[] = {
+ /* name parent min_uv max_uv headroom_uv */
+ { "l1", "vdd_l1_l2", 528000, 1504000, 225000 },
+ { "l2", "vdd_l1_l2", 528000, 1504000, 225000 },
+ { "l3", "vdd_l3_l4", 1504000, 3400000, 200000 },
+ { "l4", "vdd_l3_l4", 1504000, 3400000, 200000 },
+ { "l5", "vdd_l5", 1504000, 3400000, 300000 },
+ { "l6", "vdd_l6", 1504000, 3400000, 300000 },
+ { "l7", "vdd_l7", 1504000, 3400000, 300000 },
+ { }
+};
+
+static int pm8008_regulator_get_voltage(struct regulator_dev *rdev)
+{
+ struct pm8008_regulator *pm8008_reg = rdev_get_drvdata(rdev);
+ __le16 mV;
+ int rc;
+
+ rc = regmap_bulk_read(pm8008_reg->regmap,
+ LDO_VSET_LB_REG(pm8008_reg->base), (void *)&mV, 2);
+ if (rc < 0) {
+ dev_err(pm8008_reg->dev,
+ "failed to read regulator voltage rc=%d\n", rc);
+ return rc;
+ }
+
+ return le16_to_cpu(mV) * 1000;
+}
+
+static inline int pm8008_write_voltage(struct pm8008_regulator *pm8008_reg,
+ int min_uv, int max_uv)
+{
+ int rc, mv;
+ u16 vset_raw;
+
+ mv = DIV_ROUND_UP(min_uv, 1000);
+
+ /*
+ * Each LSB of regulator is 1mV and the voltage setpoint
+ * should be multiple of 8mV(step).
+ */
+ mv = DIV_ROUND_UP(mv, VSET_STEP_MV) * VSET_STEP_MV;
+ if (mv * 1000 > max_uv) {
+ dev_err(pm8008_reg->dev,
+ "requested voltage (%d uV) above maximum limit (%d uV)\n",
+ mv*1000, max_uv);
+ return -EINVAL;
+ }
+
+ vset_raw = cpu_to_le16(mv);
+
+ rc = regmap_bulk_write(pm8008_reg->regmap,
+ LDO_VSET_LB_REG(pm8008_reg->base),
+ (const void *)&vset_raw, sizeof(vset_raw));
+ if (rc < 0) {
+ dev_err(pm8008_reg->dev, "failed to write voltage rc=%d\n", rc);
+ return rc;
+ }
+
+ return 0;
+}
+
+static int pm8008_regulator_set_voltage_time(struct regulator_dev *rdev,
+ int old_uV, int new_uv)
+{
+ struct pm8008_regulator *pm8008_reg = rdev_get_drvdata(rdev);
+
+ return DIV_ROUND_UP(abs(new_uv - old_uV), pm8008_reg->step_rate);
+}
+
+static int pm8008_regulator_set_voltage(struct regulator_dev *rdev,
+ int min_uv, int max_uv, unsigned int *selector)
+{
+ struct pm8008_regulator *pm8008_reg = rdev_get_drvdata(rdev);
+ int rc;
+
+ rc = pm8008_write_voltage(pm8008_reg, min_uv, max_uv);
+ if (rc < 0)
+ return rc;
+
+ *selector = DIV_ROUND_UP(min_uv - pm8008_reg->rdesc.min_uV,
+ VSET_STEP_UV);
+
+ dev_dbg(pm8008_reg->dev, "voltage set to %d\n", min_uv);
+ return 0;
+}
+
+static const struct regulator_ops pm8008_regulator_ops = {
+ .enable = regulator_enable_regmap,
+ .disable = regulator_disable_regmap,
+ .is_enabled = regulator_is_enabled_regmap,
+ .set_voltage = pm8008_regulator_set_voltage,
+ .get_voltage = pm8008_regulator_get_voltage,
+ .list_voltage = regulator_list_voltage_linear,
+ .set_voltage_time = pm8008_regulator_set_voltage_time,
+};
+
+static int pm8008_regulator_of_parse(struct device_node *node,
+ const struct regulator_desc *desc,
+ struct regulator_config *config)
+{
+ struct pm8008_regulator *pm8008_reg = config->driver_data;
+ struct device *dev = config->dev;
+ int rc;
+ u8 reg;
+
+ rc = of_property_read_u32(node, "regulator-min-dropout-voltage-microvolt",
+ &pm8008_reg->rdesc.min_dropout_uV);
+ if (rc) {
+ dev_err(dev, "failed to read min-dropout voltage rc=%d\n", rc);
+ return rc;
+ }
+
+ /* get slew rate */
+ rc = regmap_bulk_read(pm8008_reg->regmap,
+ LDO_STEPPER_CTL_REG(pm8008_reg->base), (void *)&reg, 1);
+ if (rc < 0) {
+ dev_err(dev, "%s: failed to read step rate configuration rc=%d\n",
+ pm8008_reg->rdesc.name, rc);
+ return rc;
+ }
+ pm8008_reg->step_rate
+ = DEFAULT_VOLTAGE_STEPPER_RATE >> (reg & STEP_RATE_MASK);
+
+ return 0;
+}
+
+static int pm8008_regulator_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct device_node *node = pdev->dev.of_node;
+ struct pm8008_regulator *pm8008_reg;
+ struct regmap *regmap;
+ struct regulator_config reg_config = {};
+ const struct regulator_data *reg;
+ struct regulator_init_data *init_data;
+ int rc;
+ u32 base;
+
+ regmap = dev_get_regmap(dev->parent, NULL);
+ if (!regmap) {
+ dev_err(dev, "parent regmap is missing\n");
+ return -EINVAL;
+ }
+
+ for (reg = &reg_data[0]; reg->name; reg++) {
+ pm8008_reg = devm_kzalloc(dev, sizeof(*pm8008_reg), GFP_KERNEL);
+
+ pm8008_reg->regmap = regmap;
+
+ pm8008_reg->of_node = of_get_child_by_name(node, reg->name);
+ if (!pm8008_reg->of_node) {
+ dev_err(dev, "child node %s not found\n", reg->name);
+ return -ENODEV;
+ }
+
+ pm8008_reg->dev = dev;
+
+ rc = of_property_read_u32(pm8008_reg->of_node, "reg", &base);
+ if (rc < 0) {
+ dev_err(dev, "%s: failed to get regulator base rc=%d\n",
+ reg->name, rc);
+ return rc;
+ }
+ pm8008_reg->base = base;
+
+ init_data = of_get_regulator_init_data(dev, pm8008_reg->of_node,
+ &pm8008_reg->rdesc);
+ if (!init_data) {
+ dev_err(dev, "%s: failed to get regulator data\n", reg->name);
+ return -ENODATA;
+ }
+
+ pm8008_reg->rdesc.type = REGULATOR_VOLTAGE;
+ pm8008_reg->rdesc.ops = &pm8008_regulator_ops;
+ pm8008_reg->rdesc.name = init_data->constraints.name;
+ pm8008_reg->rdesc.supply_name = reg->supply_name;
+ pm8008_reg->rdesc.of_match = reg->name;
+ pm8008_reg->rdesc.of_parse_cb = pm8008_regulator_of_parse;
+ pm8008_reg->rdesc.uV_step = VSET_STEP_UV;
+ pm8008_reg->rdesc.min_uV = reg->min_uv;
+ pm8008_reg->rdesc.n_voltages
+ = ((reg->max_uv - reg->min_uv)
+ / pm8008_reg->rdesc.uV_step) + 1;
+
+ pm8008_reg->rdesc.enable_reg = LDO_ENABLE_REG(base);
+ pm8008_reg->rdesc.enable_mask = ENABLE_BIT;
+ pm8008_reg->rdesc.min_dropout_uV = reg->min_dropout_uv;
+
+ init_data->constraints.input_uV = init_data->constraints.max_uV;
+ reg_config.dev = dev;
+ reg_config.init_data = init_data;
+ reg_config.driver_data = pm8008_reg;
+ reg_config.of_node = pm8008_reg->of_node;
+
+ return PTR_ERR_OR_ZERO(devm_regulator_register(dev, &pm8008_reg->rdesc,
+ &reg_config));
+ }
+
+ return 0;
+}
+
+static const struct of_device_id pm8008_regulator_match_table[] = {
+ { .compatible = "qcom,pm8008-regulator", },
+ { }
+};
+MODULE_DEVICE_TABLE(of, pm8008_regulator_match_table);
+
+static struct platform_driver pm8008_regulator_driver = {
+ .driver = {
+ .name = "qcom,pm8008-regulator",
+ .of_match_table = pm8008_regulator_match_table,
+ },
+ .probe = pm8008_regulator_probe,
+};
+
+module_platform_driver(pm8008_regulator_driver);
+
+MODULE_DESCRIPTION("Qualcomm PM8008 PMIC Regulator Driver");
+MODULE_LICENSE("GPL v2");
--
2.7.4