Initial support for the Silergy SY7636A-regulator Power Management chip.
Signed-off-by: Alistair Francis <alist...@alistair23.me>
---
v3:
- Move sysfs power from mfd to regulaator
- Add ABI documentation
v2:
- N/A
.../testing/sysfs-driver-sy7636a-regulator | 21 ++
drivers/regulator/Kconfig | 6 +
drivers/regulator/Makefile | 1 +
drivers/regulator/sy7636a-regulator.c | 354 ++++++++++++++++++
include/linux/mfd/sy7636a.h | 1 +
5 files changed, 383 insertions(+)
create mode 100644 Documentation/ABI/testing/sysfs-driver-sy7636a-regulator
create mode 100644 drivers/regulator/sy7636a-regulator.c
diff --git a/Documentation/ABI/testing/sysfs-driver-sy7636a-regulator
b/Documentation/ABI/testing/sysfs-driver-sy7636a-regulator
new file mode 100644
index 000000000000..ab534a8ea21a
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-driver-sy7636a-regulator
@@ -0,0 +1,21 @@
+What: /sys/bus/regulator/drivers/sy7636a-regulator/state
+Date: April 2021
+KernelVersion: 5.12
+Contact: alist...@alistair23.me
+Description:
+ This file allows you to see the current power rail state.
+
+What: /sys/bus/regulator/drivers/sy7636a-regulator/power_good
+Date: April 2021
+KernelVersion: 5.12
+Contact: alist...@alistair23.me
+Description:
+ This file allows you to see the current state of the regulator
+ as either ON or OFF.
+
+What: /sys/bus/regulator/drivers/sy7636a-regulator/vcom
+Date: April 2021
+KernelVersion: 5.12
+Contact: alist...@alistair23.me
+Description:
+ This file allows you to see and set the current voltage in mV.
diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig
index 77c43134bc9e..6d501ce921a8 100644
--- a/drivers/regulator/Kconfig
+++ b/drivers/regulator/Kconfig
@@ -1130,6 +1130,12 @@ config REGULATOR_STW481X_VMMC
This driver supports the internal VMMC regulator in the STw481x
PMIC chips.
+config REGULATOR_SY7636A
+ tristate "Silergy SY7636A voltage regulator"
+ depends on MFD_SY7636A
+ help
+ This driver supports Silergy SY3686A voltage regulator.
+
config REGULATOR_SY8106A
tristate "Silergy SY8106A regulator"
depends on I2C && (OF || COMPILE_TEST)
diff --git a/drivers/regulator/Makefile b/drivers/regulator/Makefile
index 44d2f8bf4b74..5a981036a9f0 100644
--- a/drivers/regulator/Makefile
+++ b/drivers/regulator/Makefile
@@ -134,6 +134,7 @@ obj-$(CONFIG_REGULATOR_STM32_VREFBUF) += stm32-vrefbuf.o
obj-$(CONFIG_REGULATOR_STM32_PWR) += stm32-pwr.o
obj-$(CONFIG_REGULATOR_STPMIC1) += stpmic1_regulator.o
obj-$(CONFIG_REGULATOR_STW481X_VMMC) += stw481x-vmmc.o
+obj-$(CONFIG_REGULATOR_SY7636A) += sy7636a-regulator.o
obj-$(CONFIG_REGULATOR_SY8106A) += sy8106a-regulator.o
obj-$(CONFIG_REGULATOR_SY8824X) += sy8824x.o
obj-$(CONFIG_REGULATOR_SY8827N) += sy8827n.o
diff --git a/drivers/regulator/sy7636a-regulator.c
b/drivers/regulator/sy7636a-regulator.c
new file mode 100644
index 000000000000..0ec6f852cb3d
--- /dev/null
+++ b/drivers/regulator/sy7636a-regulator.c
@@ -0,0 +1,354 @@
+// SPDX-License-Identifier: GPL-2.0+
+//
+// Functions to access SY3686A power management chip voltages
+//
+// Copyright (C) 2019 reMarkable AS - http://www.remarkable.com/
+//
+// Authors: Lars Ivar Miljeteig <lars.ivar.miljet...@remarkable.com>
+// Alistair Francis <alist...@alistair23.me>
+
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/sysfs.h>
+#include <linux/gpio/consumer.h>
+#include <linux/mfd/sy7636a.h>
+
+static const char * const states[] = {
+ "no fault event",
+ "UVP at VP rail",
+ "UVP at VN rail",
+ "UVP at VPOS rail",
+ "UVP at VNEG rail",
+ "UVP at VDDH rail",
+ "UVP at VEE rail",
+ "SCP at VP rail",
+ "SCP at VN rail",
+ "SCP at VPOS rail",
+ "SCP at VNEG rail",
+ "SCP at VDDH rail",
+ "SCP at VEE rail",
+ "SCP at V COM rail",
+ "UVLO",
+ "Thermal shutdown",
+};
+
+static int sy7636a_get_vcom_voltage_mv(struct regmap *regmap)
+{
+ int ret;
+ unsigned int val, val_h;
+
+ ret = regmap_read(regmap, SY7636A_REG_VCOM_ADJUST_CTRL_L, &val);
+ if (ret)
+ return ret;
+
+ ret = regmap_read(regmap, SY7636A_REG_VCOM_ADJUST_CTRL_H, &val_h);
+ if (ret)
+ return ret;
+
+ val |= (val_h << VCOM_ADJUST_CTRL_SHIFT);
+
+ return (val & VCOM_ADJUST_CTRL_MASK) * VCOM_ADJUST_CTRL_SCAL;
+}
+
+static int sy7636a_set_vcom_voltage_mv(struct regmap *regmap, unsigned int
vcom)
+{
+ int ret;
+ unsigned int val;
+
+ if (vcom < VCOM_MIN || vcom > VCOM_MAX)
+ return -EINVAL;
+
+ val = (unsigned int)(vcom / VCOM_ADJUST_CTRL_SCAL) &
VCOM_ADJUST_CTRL_MASK;
+
+ ret = regmap_write(regmap, SY7636A_REG_VCOM_ADJUST_CTRL_L, val);
+ if (ret)
+ return ret;
+
+ ret = regmap_write(regmap, SY7636A_REG_VCOM_ADJUST_CTRL_H, val >>
VCOM_ADJUST_CTRL_SHIFT);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+static ssize_t state_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ int ret;
+ unsigned int val;
+ struct sy7636a *sy7636a = dev_get_drvdata(dev);
+
+ ret = regmap_read(sy7636a->regmap, SY7636A_REG_FAULT_FLAG, &val);
+ if (ret) {
+ dev_err(sy7636a->dev, "Failed to read from device\n");
+ return ret;
+ }
+
+ val = val >> FAULT_FLAG_SHIFT;
+
+ if (val >= ARRAY_SIZE(states)) {
+ dev_err(sy7636a->dev, "Unexpected value read from device:
%u\n", val);
+ return -EINVAL;
+ }
+
+ return snprintf(buf, PAGE_SIZE, "%s\n", states[val]);
+}
+static DEVICE_ATTR(state, 0444, state_show, NULL);
+
+static ssize_t power_good_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ int ret;
+ unsigned int val;
+ struct sy7636a *sy7636a = dev_get_drvdata(dev);
+
+ ret = regmap_read(sy7636a->regmap, SY7636A_REG_FAULT_FLAG, &val);
+ if (ret) {
+ dev_err(sy7636a->dev, "Failed to read from device\n");
+ return ret;
+ }
+
+ val &= (1 << FAULT_FLAG_SHIFT) - 1;
+
+ return snprintf(buf, PAGE_SIZE, "%s\n", val ? "ON" : "OFF");
+}
+static DEVICE_ATTR(power_good, 0444, power_good_show, NULL);
+
+static ssize_t vcom_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ int ret;
+ struct sy7636a *sy7636a = dev_get_drvdata(dev);
+
+ ret = sy7636a_get_vcom_voltage_mv(sy7636a->regmap);
+ if (ret < 0)
+ return ret;
+
+ return snprintf(buf, PAGE_SIZE, "%d\n", -ret);
+}
+static ssize_t vcom_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ int ret;
+ int vcom;
+ struct sy7636a *sy7636a = dev_get_drvdata(dev);
+
+ ret = kstrtoint(buf, 0, &vcom);
+ if (ret)
+ return ret;
+
+ if (vcom > 0 || vcom < -5000)
+ return -EINVAL;
+
+ ret = sy7636a_set_vcom_voltage_mv(sy7636a->regmap, (unsigned
int)(-vcom));
+ if (ret)
+ return ret;
+
+ return count;
+}
+static DEVICE_ATTR(vcom, 0644, vcom_show, vcom_store);
+
+static struct attribute *sy7636a_sysfs_attrs[] = {
+ &dev_attr_state.attr,
+ &dev_attr_power_good.attr,
+ &dev_attr_vcom.attr,
+ NULL,
+};
+
+static const struct attribute_group sy7636a_sysfs_attr_group = {
+ .attrs = sy7636a_sysfs_attrs,
+};
+
+static int sy7636a_get_vcom_voltage_op(struct regulator_dev *rdev)
+{
+ return sy7636a_get_vcom_voltage_mv(rdev->regmap);
+}
+
+static int sy7636a_disable_regulator(struct regulator_dev *rdev)
+{
+ int ret = 0;
+
+ ret = regulator_disable_regmap(rdev);
+ // Delay for ~35ms after disabling the regulator, to allow power ramp
+ // down to go undisturbed
+ usleep_range(30000, 35000);
+
+ return ret;
+}
+
+static int sy7636a_regulator_is_enabled(struct regulator_dev *rdev)
+{
+ return regulator_is_enabled_regmap(rdev);
+}
+
+static int sy7636a_get_status(struct regulator_dev *rdev)
+{
+ struct sy7636a *sy7636a = dev_get_drvdata(rdev->dev.parent);
+ int pwr_good = 0;
+ const unsigned int wait_time = 500;
+ unsigned int wait_cnt;
+ int ret = 0;
+
+ for (wait_cnt = 0; wait_cnt < wait_time; wait_cnt++) {
+ pwr_good = gpiod_get_value_cansleep(sy7636a->pgood_gpio);
+ if (pwr_good < 0) {
+ dev_err(&rdev->dev, "Failed to read pgood gpio: %d\n",
pwr_good);
+ ret = pwr_good;
+ return ret;
+ } else if (pwr_good)
+ break;
+
+ usleep_range(1000, 1500);
+ }
+
+ return ret;
+}
+
+static int sy7636a_enable_regulator_pgood(struct regulator_dev *rdev)
+{
+ struct sy7636a *sy7636a = dev_get_drvdata(rdev->dev.parent);
+ int pwr_good = 0;
+ int ret = 0;
+ unsigned long t0, t1;
+ const unsigned int wait_time = 500;
+ unsigned int wait_cnt;
+
+ t0 = jiffies;
+
+ ret = regulator_enable_regmap(rdev);
+ if (ret)
+ goto finish;
+
+ for (wait_cnt = 0; wait_cnt < wait_time; wait_cnt++) {
+ pwr_good = gpiod_get_value_cansleep(sy7636a->pgood_gpio);
+ if (pwr_good < 0) {
+ dev_err(&rdev->dev, "Failed to read pgood gpio: %d\n",
pwr_good);
+ ret = pwr_good;
+ goto finish;
+ } else if (pwr_good)
+ break;
+
+ usleep_range(1000, 1500);
+ }
+
+ t1 = jiffies;
+
+ if (!pwr_good) {
+ dev_err(&rdev->dev, "Power good signal timeout after %u ms\n",
+ jiffies_to_msecs(t1 - t0));
+ ret = -ETIME;
+ sy7636a_disable_regulator(rdev);
+ goto finish;
+ }
+
+ ret = sysfs_create_group(&rdev->dev.kobj, &sy7636a_sysfs_attr_group);
+ if (ret) {
+ dev_err(sy7636a->dev, "Failed to create sysfs attributes\n");
+ return ret;
+ }
+
+ if (ret) {
+ dev_err(sy7636a->dev, "Failed to add child devices\n");
+ sysfs_remove_group(&rdev->dev.kobj, &sy7636a_sysfs_attr_group);
+ return ret;
+ }
+
+ dev_dbg(&rdev->dev, "Power good OK (took %u ms, %u waits)\n",
+ jiffies_to_msecs(t1 - t0),
+ wait_cnt);
+
+finish:
+ return ret;
+}
+
+static const struct regulator_ops sy7636a_vcom_volt_ops = {
+ .get_voltage = sy7636a_get_vcom_voltage_op,
+ .enable = sy7636a_enable_regulator_pgood,
+ .disable = sy7636a_disable_regulator,
+ .is_enabled = sy7636a_regulator_is_enabled,
+ .get_status = sy7636a_get_status,
+};
+
+struct regulator_desc desc = {
+ .name = "vcom",
+ .id = 0,
+ .ops = &sy7636a_vcom_volt_ops,
+ .type = REGULATOR_VOLTAGE,
+ .owner = THIS_MODULE,
+ .enable_reg = SY7636A_REG_OPERATION_MODE_CRL,
+ .enable_mask = SY7636A_OPERATION_MODE_CRL_ONOFF,
+ .regulators_node = of_match_ptr("regulators"),
+ .of_match = of_match_ptr("vcom"),
+};
+
+static int sy7636a_regulator_init(struct sy7636a *sy7636a)
+{
+ return regmap_write(sy7636a->regmap,
+ SY7636A_REG_POWER_ON_DELAY_TIME,
+ 0x0);
+}
+
+static int sy7636a_regulator_probe(struct platform_device *pdev)
+{
+ struct sy7636a *sy7636a = dev_get_drvdata(pdev->dev.parent);
+ struct regulator_config config = { };
+ struct regulator_dev *rdev;
+ struct gpio_desc *gdp;
+ int ret;
+
+ if (!sy7636a)
+ return -EPROBE_DEFER;
+
+ platform_set_drvdata(pdev, sy7636a);
+
+ gdp = devm_gpiod_get(sy7636a->dev, "epd-pwr-good", GPIOD_IN);
+ if (IS_ERR(gdp)) {
+ dev_err(sy7636a->dev, "Power good GPIO fault %ld\n",
PTR_ERR(gdp));
+ return PTR_ERR(gdp);
+ }
+
+ sy7636a->pgood_gpio = gdp;
+
+ ret = sy7636a_regulator_init(sy7636a);
+ if (ret) {
+ dev_err(sy7636a->dev, "Failed to initialize regulator: %d\n",
ret);
+ return ret;
+ }
+
+ config.dev = &pdev->dev;
+ config.dev->of_node = sy7636a->dev->of_node;
+ config.driver_data = sy7636a;
+ config.regmap = sy7636a->regmap;
+
+ rdev = devm_regulator_register(&pdev->dev, &desc, &config);
+ if (IS_ERR(rdev)) {
+ dev_err(sy7636a->dev, "Failed to register %s regulator\n",
+ pdev->name);
+ return PTR_ERR(rdev);
+ }
+
+ return 0;
+}
+
+static const struct platform_device_id sy7636a_regulator_id_table[] = {
+ { "sy7636a-regulator", },
+};
+MODULE_DEVICE_TABLE(platform, sy7636a_regulator_id_table);
+
+static struct platform_driver sy7636a_regulator_driver = {
+ .driver = {
+ .name = "sy7636a-regulator",
+ },
+ .probe = sy7636a_regulator_probe,
+ .id_table = sy7636a_regulator_id_table,
+};
+module_platform_driver(sy7636a_regulator_driver);
+
+MODULE_AUTHOR("Lars Ivar Miljeteig <lars.ivar.miljet...@remarkable.com>");
+MODULE_DESCRIPTION("SY7636A voltage regulator driver");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/mfd/sy7636a.h b/include/linux/mfd/sy7636a.h
index a5ec5d911b3a..1f8d7507a700 100644
--- a/include/linux/mfd/sy7636a.h
+++ b/include/linux/mfd/sy7636a.h
@@ -41,6 +41,7 @@
struct sy7636a {
struct device *dev;
struct regmap *regmap;
+ struct gpio_desc *pgood_gpio;
};
#endif /* __LINUX_MFD_SY7636A_H */
--
2.31.0
