[PATCH v4 1/5] dt-bindings: mfd: Initial commit of silergy,sy7636a.yaml

[PATCH v4 1/5] dt-bindings: mfd: Initial commit of silergy,sy7636a.yaml

[Alistair Francis]

Initial support for the Silergy SY7636A Power Management chip
and regulator.

Signed-off-by: Alistair Francis <alistair@alistair23.me>
---
v3:
 - No change
v2:
 - N/A

 .../bindings/mfd/silergy,sy7636a.yaml         | 63 +++++++++++++++++++
 1 file changed, 63 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mfd/silergy,sy7636a.yaml

diff --git a/Documentation/devicetree/bindings/mfd/silergy,sy7636a.yaml b/Documentation/devicetree/bindings/mfd/silergy,sy7636a.yaml
new file mode 100644
index 000000000000..f260a8eae226
--- /dev/null
+++ b/Documentation/devicetree/bindings/mfd/silergy,sy7636a.yaml
@@ -0,0 +1,63 @@
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/mfd/silergy,sy7636a.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: silergy sy7636a PMIC
+
+maintainers:
+  - Alistair Francis <alistair@alistair23.me>
+
+properties:
+  compatible:
+    const: silergy,sy7636a
+
+  reg:
+    maxItems: 1
+
+  '#thermal-sensor-cells':
+    const: 0
+
+  regulators:
+    type: object
+    $ref: /schemas/regulator/regulator.yaml#
+
+    properties:
+      compatible:
+        const: silergy,sy7636a-regulator
+
+      regulator-name:
+        pattern: "vcom"
+
+required:
+  - compatible
+  - reg
+  - '#thermal-sensor-cells'
+
+additionalProperties: false
+
+examples:
+  - |
+    i2c {
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      sy7636a@62 {
+        compatible = "silergy,sy7636a";
+        reg = <0x62>;
+        status = "okay";
+        pinctrl-names = "default";
+        pinctrl-0 = <&pinctrl_epdpmic>;
+        #thermal-sensor-cells = <0>;
+
+        regulators {
+          compatible = "silergy,sy7636a-regulator";
+          reg_epdpmic: vcom {
+            regulator-name = "vcom";
+            regulator-boot-on;
+          };
+        };
+      };
+    };
+...
-- 
2.31.0

[PATCH v4 2/5] mfd: sy7636a: Initial commit

[Alistair Francis]

Initial support for the Silergy SY7636A Power Management chip.

Signed-off-by: Alistair Francis <alistair@alistair23.me>
---
v3:
 - Update copyright year
 - Move power parts to regulator
 - Change Kconfig depends to be tristate
v2:
 - Address comments from review

 drivers/mfd/Kconfig         | 10 +++++
 drivers/mfd/Makefile        |  1 +
 drivers/mfd/sy7636a.c       | 82 +++++++++++++++++++++++++++++++++++++
 include/linux/mfd/sy7636a.h | 46 +++++++++++++++++++++
 4 files changed, 139 insertions(+)
 create mode 100644 drivers/mfd/sy7636a.c
 create mode 100644 include/linux/mfd/sy7636a.h

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index b74efa469e90..ac09b40e1724 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -1351,6 +1351,16 @@ config MFD_SYSCON
 	  Select this option to enable accessing system control registers
 	  via regmap.
 
+config MFD_SY7636A
+	tristate "Silergy SY7636A Power Management chip"
+	select MFD_CORE
+	select REGMAP_I2C
+	select REGMAP_IRQ
+	depends on I2C
+	help
+	  Select this option to enable support for the Silergy SY7636A
+	  Power Management chip.
+
 config MFD_DAVINCI_VOICECODEC
 	tristate
 	select MFD_CORE
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index 834f5463af28..5bfa0d6e5dc5 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -265,6 +265,7 @@ obj-$(CONFIG_MFD_STMFX) 	+= stmfx.o
 obj-$(CONFIG_MFD_KHADAS_MCU) 	+= khadas-mcu.o
 obj-$(CONFIG_MFD_ACER_A500_EC)	+= acer-ec-a500.o
 
+obj-$(CONFIG_MFD_SY7636A)	+= sy7636a.o
 obj-$(CONFIG_SGI_MFD_IOC3)	+= ioc3.o
 obj-$(CONFIG_MFD_SIMPLE_MFD_I2C)	+= simple-mfd-i2c.o
 obj-$(CONFIG_MFD_INTEL_M10_BMC)   += intel-m10-bmc.o
diff --git a/drivers/mfd/sy7636a.c b/drivers/mfd/sy7636a.c
new file mode 100644
index 000000000000..e08f29ea63f8
--- /dev/null
+++ b/drivers/mfd/sy7636a.c
@@ -0,0 +1,82 @@
+// SPDX-License-Identifier: GPL-2.0+
+//
+// MFD parent driver for SY7636A chip
+//
+// Copyright (C) 2021 reMarkable AS - http://www.remarkable.com/
+//
+// Authors: Lars Ivar Miljeteig <lars.ivar.miljeteig@remarkable.com>
+//          Alistair Francis <alistair@alistair23.me>
+//
+// Based on the lp87565 driver by Keerthy <j-keerthy@ti.com>
+
+#include <linux/interrupt.h>
+#include <linux/mfd/core.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+
+#include <linux/mfd/sy7636a.h>
+
+static const struct regmap_config sy7636a_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+};
+
+static const struct mfd_cell sy7636a_cells[] = {
+	{ .name = "sy7636a-regulator", },
+	{ .name = "sy7636a-temperature", },
+	{ .name = "sy7636a-thermal", },
+};
+
+static const struct of_device_id of_sy7636a_match_table[] = {
+	{ .compatible = "silergy,sy7636a", },
+	{}
+};
+MODULE_DEVICE_TABLE(of, of_sy7636a_match_table);
+
+static int sy7636a_probe(struct i2c_client *client,
+			 const struct i2c_device_id *ids)
+{
+	struct sy7636a *sy7636a;
+	int ret;
+
+	sy7636a = devm_kzalloc(&client->dev, sizeof(*sy7636a), GFP_KERNEL);
+	if (!sy7636a)
+		return -ENOMEM;
+
+	sy7636a->dev = &client->dev;
+
+	sy7636a->regmap = devm_regmap_init_i2c(client, &sy7636a_regmap_config);
+	if (IS_ERR(sy7636a->regmap)) {
+		ret = PTR_ERR(sy7636a->regmap);
+		dev_err(sy7636a->dev,
+			"Failed to initialize register map: %d\n", ret);
+		return ret;
+	}
+
+	i2c_set_clientdata(client, sy7636a);
+
+	ret = devm_mfd_add_devices(sy7636a->dev, PLATFORM_DEVID_AUTO,
+					sy7636a_cells, ARRAY_SIZE(sy7636a_cells),
+					NULL, 0, NULL);
+	return 0;
+}
+
+static const struct i2c_device_id sy7636a_id_table[] = {
+	{ "sy7636a", 0 },
+	{ },
+};
+MODULE_DEVICE_TABLE(i2c, sy7636a_id_table);
+
+static struct i2c_driver sy7636a_driver = {
+	.driver	= {
+		.name	= "sy7636a",
+		.of_match_table = of_sy7636a_match_table,
+	},
+	.probe = sy7636a_probe,
+	.id_table = sy7636a_id_table,
+};
+module_i2c_driver(sy7636a_driver);
+
+MODULE_AUTHOR("Lars Ivar Miljeteig <lars.ivar.miljeteig@remarkable.com>");
+MODULE_DESCRIPTION("Silergy SY7636A Multi-Function Device Driver");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/mfd/sy7636a.h b/include/linux/mfd/sy7636a.h
new file mode 100644
index 000000000000..a5ec5d911b3a
--- /dev/null
+++ b/include/linux/mfd/sy7636a.h
@@ -0,0 +1,46 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Functions to access SY3686A power management chip.
+ *
+ * Copyright (C) 2021 reMarkable AS - http://www.remarkable.com/
+ */
+
+#ifndef __MFD_SY7636A_H
+#define __MFD_SY7636A_H
+
+#include <linux/i2c.h>
+#include <linux/regmap.h>
+#include <linux/regulator/driver.h>
+#include <linux/regulator/machine.h>
+
+#define SY7636A_REG_OPERATION_MODE_CRL		0x00
+#define SY7636A_OPERATION_MODE_CRL_VCOMCTL	BIT(6)
+#define SY7636A_OPERATION_MODE_CRL_ONOFF	BIT(7)
+#define SY7636A_REG_VCOM_ADJUST_CTRL_L		0x01
+#define SY7636A_REG_VCOM_ADJUST_CTRL_H		0x02
+#define SY7636A_REG_VCOM_ADJUST_CTRL_MASK	0x01ff
+#define SY7636A_REG_VLDO_VOLTAGE_ADJULST_CTRL	0x03
+#define SY7636A_REG_POWER_ON_DELAY_TIME		0x06
+#define SY7636A_REG_FAULT_FLAG			0x07
+#define SY7636A_FAULT_FLAG_PG			BIT(0)
+#define SY7636A_REG_TERMISTOR_READOUT		0x08
+
+#define SY7636A_REG_MAX				0x08
+
+#define VCOM_MIN		0
+#define VCOM_MAX		5000
+
+#define VCOM_ADJUST_CTRL_MASK	0x1ff
+// Used to shift the high byte
+#define VCOM_ADJUST_CTRL_SHIFT	8
+// Used to scale from VCOM_ADJUST_CTRL to mv
+#define VCOM_ADJUST_CTRL_SCAL	10
+
+#define FAULT_FLAG_SHIFT	1
+
+struct sy7636a {
+	struct device *dev;
+	struct regmap *regmap;
+};
+
+#endif /* __LINUX_MFD_SY7636A_H */
-- 
2.31.0

[PATCH v4 3/5] regulator: sy7636a: Initial commit

[Alistair Francis]

Initial support for the Silergy SY7636A-regulator Power Management chip.

Signed-off-by: Alistair Francis <alistair@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:	alistair@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:	alistair@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:	alistair@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.miljeteig@remarkable.com>
+//          Alistair Francis <alistair@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.miljeteig@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

[PATCH v4 4/5] ARM: imx_v6_v7_defconfig: Enable silergy,sy7636a

[Alistair Francis]

Enable the silergy,sy7636a and silergy,sy7636a-regulator for the
reMarkable2.

Signed-off-by: Alistair Francis <alistair@alistair23.me>
---
v3:
 - Change patch title
v2:
 - N/A

 arch/arm/configs/imx_v6_v7_defconfig | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/arm/configs/imx_v6_v7_defconfig b/arch/arm/configs/imx_v6_v7_defconfig
index cd80e85d37cf..bafd1d7b4ad5 100644
--- a/arch/arm/configs/imx_v6_v7_defconfig
+++ b/arch/arm/configs/imx_v6_v7_defconfig
@@ -245,6 +245,7 @@ CONFIG_MFD_MC13XXX_I2C=y
 CONFIG_MFD_RN5T618=y
 CONFIG_MFD_STMPE=y
 CONFIG_REGULATOR=y
+CONFIG_MFD_SY7636A=y
 CONFIG_REGULATOR_FIXED_VOLTAGE=y
 CONFIG_REGULATOR_ANATOP=y
 CONFIG_REGULATOR_DA9052=y
@@ -255,6 +256,7 @@ CONFIG_REGULATOR_MC13783=y
 CONFIG_REGULATOR_MC13892=y
 CONFIG_REGULATOR_PFUZE100=y
 CONFIG_REGULATOR_RN5T618=y
+CONFIG_REGULATOR_SY7636A=y
 CONFIG_RC_CORE=y
 CONFIG_RC_DEVICES=y
 CONFIG_IR_GPIO_CIR=y
-- 
2.31.0

[PATCH v4 5/5] ARM: dts: imx7d: remarkable2: Enable silergy,sy7636a

[Alistair Francis]

Enable the silergy,sy7636a and silergy,sy7636a-regulator on the
reMarkable2.

Signed-off-by: Alistair Francis <alistair@alistair23.me>
---
v3:
 - Change patch title
v2:
 - N/A

 arch/arm/boot/dts/imx7d-remarkable2.dts | 61 +++++++++++++++++++++++++
 1 file changed, 61 insertions(+)

diff --git a/arch/arm/boot/dts/imx7d-remarkable2.dts b/arch/arm/boot/dts/imx7d-remarkable2.dts
index 791ad55281cc..37834bc7fc72 100644
--- a/arch/arm/boot/dts/imx7d-remarkable2.dts
+++ b/arch/arm/boot/dts/imx7d-remarkable2.dts
@@ -22,6 +22,27 @@ memory@80000000 {
 		reg = <0x80000000 0x40000000>;
 	};
 
+	thermal-zones {
+		epd-thermal {
+			thermal-sensors = <&epd_pmic>;
+			polling-delay-passive = <30000>;
+			polling-delay = <30000>;
+			trips {
+				trip0 {
+					temperature = <49000>;
+					hysteresis = <2000>;
+					type = "passive";
+				};
+
+				trip1 {
+					temperature = <50000>;
+					hysteresis = <2000>;
+					type = "critical";
+				};
+			};
+		};
+	};
+
 	reg_brcm: regulator-brcm {
 		compatible = "regulator-fixed";
 		regulator-name = "brcm_reg";
@@ -86,6 +107,32 @@ wacom_digitizer: digitizer@9 {
 	};
 };
 
+&i2c4 {
+	clock-frequency = <100000>;
+	pinctrl-names = "default", "sleep";
+	pinctrl-0 = <&pinctrl_i2c4>;
+	pinctrl-1 = <&pinctrl_i2c4>;
+	status = "okay";
+
+	epd_pmic: sy7636a@62 {
+		compatible = "silergy,sy7636a";
+		reg = <0x62>;
+		status = "okay";
+		pinctrl-names = "default";
+		pinctrl-0 = <&pinctrl_epdpmic>;
+		#thermal-sensor-cells = <0>;
+
+		epd-pwr-good-gpios = <&gpio6 21 GPIO_ACTIVE_HIGH>;
+		regulators {
+			compatible = "silergy,sy7636a-regulator";
+			reg_epdpmic: vcom {
+				regulator-name = "vcom";
+				regulator-boot-on;
+			};
+		};
+	};
+};
+
 &snvs_pwrkey {
 	status = "okay";
 };
@@ -179,6 +226,13 @@ MX7D_PAD_SAI1_TX_BCLK__GPIO6_IO13	0x14
 		>;
 	};
 
+	pinctrl_epdpmic: epdpmicgrp {
+		fsl,pins = <
+			MX7D_PAD_SAI2_RX_DATA__GPIO6_IO21 0x00000074
+			MX7D_PAD_ENET1_RGMII_TXC__GPIO7_IO11 0x00000014
+		>;
+	};
+
 	pinctrl_i2c1: i2c1grp {
 		fsl,pins = <
 			MX7D_PAD_I2C1_SDA__I2C1_SDA		0x4000007f
@@ -186,6 +240,13 @@ MX7D_PAD_I2C1_SCL__I2C1_SCL		0x4000007f
 		>;
 	};
 
+	pinctrl_i2c4: i2c4grp {
+		fsl,pins = <
+			MX7D_PAD_I2C4_SDA__I2C4_SDA		0x4000007f
+			MX7D_PAD_I2C4_SCL__I2C4_SCL		0x4000007f
+		>;
+	};
+
 	pinctrl_uart1: uart1grp {
 		fsl,pins = <
 			MX7D_PAD_UART1_TX_DATA__UART1_DCE_TX	0x79
-- 
2.31.0

Re: [PATCH v4 1/5] dt-bindings: mfd: Initial commit of silergy,sy7636a.yaml

[Rob Herring]

On Thu, Mar 25, 2021 at 09:55:07PM -0400, Alistair Francis wrote:
> Initial support for the Silergy SY7636A Power Management chip
> and regulator.
> 
> Signed-off-by: Alistair Francis <alistair@alistair23.me>
> ---
> v3:
>  - No change
> v2:
>  - N/A
> 
>  .../bindings/mfd/silergy,sy7636a.yaml         | 63 +++++++++++++++++++
>  1 file changed, 63 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/mfd/silergy,sy7636a.yaml
> 
> diff --git a/Documentation/devicetree/bindings/mfd/silergy,sy7636a.yaml b/Documentation/devicetree/bindings/mfd/silergy,sy7636a.yaml
> new file mode 100644
> index 000000000000..f260a8eae226
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mfd/silergy,sy7636a.yaml
> @@ -0,0 +1,63 @@
> +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/mfd/silergy,sy7636a.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: silergy sy7636a PMIC
> +
> +maintainers:
> +  - Alistair Francis <alistair@alistair23.me>
> +
> +properties:
> +  compatible:
> +    const: silergy,sy7636a
> +
> +  reg:
> +    maxItems: 1
> +
> +  '#thermal-sensor-cells':
> +    const: 0
> +
> +  regulators:
> +    type: object
> +    $ref: /schemas/regulator/regulator.yaml#

This isn't right as the actual regulators are child nodes of 
'regulators'. So you need another level defined here.

This node should also have 'additionalProperties: false' which will 
highlight the errors here.

> +
> +    properties:
> +      compatible:
> +        const: silergy,sy7636a-regulator
> +
> +      regulator-name:
> +        pattern: "vcom"

Not a pattern. Use 'const'.

> +
> +required:
> +  - compatible
> +  - reg
> +  - '#thermal-sensor-cells'
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    i2c {
> +      #address-cells = <1>;
> +      #size-cells = <0>;
> +
> +      sy7636a@62 {

pmic@62

> +        compatible = "silergy,sy7636a";
> +        reg = <0x62>;
> +        status = "okay";
> +        pinctrl-names = "default";
> +        pinctrl-0 = <&pinctrl_epdpmic>;
> +        #thermal-sensor-cells = <0>;
> +
> +        regulators {
> +          compatible = "silergy,sy7636a-regulator";
> +          reg_epdpmic: vcom {
> +            regulator-name = "vcom";
> +            regulator-boot-on;
> +          };
> +        };
> +      };
> +    };
> +...
> -- 
> 2.31.0
> 

Re: [PATCH v4 3/5] regulator: sy7636a: Initial commit

[Mark Brown]

[-- Attachment #1: Type: text/plain, Size: 3465 bytes --]

On Thu, Mar 25, 2021 at 09:55:09PM -0400, Alistair Francis wrote:

> Initial support for the Silergy SY7636A-regulator Power Management chip.

In general this driver seems like it's trying to implement a bunch of
policy and extra features beyond standard regulator support - please
strip it back more, if you feel that there's things that really do need
to be added in the driver itself post them as separate patches.  It's
also open coding some features the core provides.  This should all make
the driver much smaller and simpler.

> +++ 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

None of these sysfs files are appropriate for a driver, if they are
useful they should be added to the core (but some of them seem like
they duplicate files that already exist, this one being an example).
There's absolutely nothing device specific about any of them.

> +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);

If this is needed add it to the core, but really this sort of stuff is
going to be very board specific - it'll depend on what the load on the
regulator is - and it's pretty rare for anything to care, you don't have
the same issues you have on enable.

> +static int sy7636a_regulator_is_enabled(struct regulator_dev *rdev)
> +{
> +	return regulator_is_enabled_regmap(rdev);
> +}

Just use the generic operation, this wrapper is not adding anything
except code size.

> +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;

This should just read the status, if the caller wants to retry for a
while then the caller can make that decision.

> +	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);

Use poll_enabled_time to check the status, no need for a custom enable
operation.

> +			ret = pwr_good;
> +			goto finish;
> +		} else if (pwr_good)
> +			break;

As per coding-style.rst both sides of the if statement should use braces
if one does.

> +	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* the driver is creating sysfs devices it *definitely* shouldn't be
creating and destroying them dynamically at runtime.

> +	ret = sy7636a_regulator_init(sy7636a);
> +	if (ret) {
> +		dev_err(sy7636a->dev, "Failed to initialize regulator: %d\n", ret);
> +		return ret;
> +	}

This function has one caller and one statement in it, just inline it.

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 488 bytes --]

Re: [PATCH v4 2/5] mfd: sy7636a: Initial commit

[Mark Brown]

[-- Attachment #1: Type: text/plain, Size: 249 bytes --]

On Thu, Mar 25, 2021 at 09:55:08PM -0400, Alistair Francis wrote:

> +config MFD_SY7636A
> +	tristate "Silergy SY7636A Power Management chip"
> +	select MFD_CORE
> +	select REGMAP_I2C
> +	select REGMAP_IRQ

This selects but does not use regmap-irq.

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 488 bytes --]