This is a multi-function device to interface with the sy7636a
EPD PMIC chip from Silergy.
Signed-off-by: Alistair Francis <alistair@xxxxxxxxxxxxx>
---
Documentation/hwmon/index.rst | 1 +
Documentation/hwmon/sy7636a-hwmon.rst | 26 +++++++
drivers/hwmon/Kconfig | 9 +++
drivers/hwmon/Makefile | 1 +
drivers/hwmon/sy7636a-hwmon.c | 106 ++++++++++++++++++++++++++
5 files changed, 143 insertions(+)
create mode 100644 Documentation/hwmon/sy7636a-hwmon.rst
create mode 100644 drivers/hwmon/sy7636a-hwmon.c
diff --git a/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst
index 7046bf1870d9..a887308850cd 100644
--- a/Documentation/hwmon/index.rst
+++ b/Documentation/hwmon/index.rst
@@ -180,6 +180,7 @@ Hardware Monitoring Kernel Drivers
smsc47m1
sparx5-temp
stpddc60
+ sy7636a-hwmon
tc654
tc74
thmc50
diff --git a/Documentation/hwmon/sy7636a-hwmon.rst b/Documentation/hwmon/sy7636a-hwmon.rst
new file mode 100644
index 000000000000..5612079397d5
--- /dev/null
+++ b/Documentation/hwmon/sy7636a-hwmon.rst
@@ -0,0 +1,26 @@
+.. SPDX-License-Identifier: GPL-2.0-or-later
+
+Kernel driver sy7636a-hwmon
+=========================
+
+Supported chips:
+
+ * Silergy SY7636A PMIC
+
+
+Description
+-----------
+
+This driver adds hardware temperature reading support for
+the Silergy SY7636A PMIC.
+
+The following sensors are supported
+
+ * Temperature
+ - SoC on-die temperature in milli-degree C
+
+sysfs-Interface
+---------------
+
+temp0_input
+ - SoC on-die temperature (milli-degree C)
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 64bd3dfba2c4..3139a286c35a 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -1662,6 +1662,15 @@ config SENSORS_SIS5595
This driver can also be built as a module. If so, the module
will be called sis5595.
+config SENSORS_SY7636A
+ tristate "Silergy SY7636A"
+ help
+ If you say yes here you get support for the thermistor readout of
+ the Silergy SY7636A PMIC.
+
+ This driver can also be built as a module. If so, the module
+ will be called sy7636a-hwmon.
+
config SENSORS_DME1737
tristate "SMSC DME1737, SCH311x and compatibles"
depends on I2C && !PPC
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index baee6a8d4dd1..8f8da52098d1 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -182,6 +182,7 @@ obj-$(CONFIG_SENSORS_SMSC47M1) += smsc47m1.o
obj-$(CONFIG_SENSORS_SMSC47M192)+= smsc47m192.o
obj-$(CONFIG_SENSORS_SPARX5) += sparx5-temp.o
obj-$(CONFIG_SENSORS_STTS751) += stts751.o
+obj-$(CONFIG_SENSORS_SY7636A) += sy7636a-hwmon.o
obj-$(CONFIG_SENSORS_AMC6821) += amc6821.o
obj-$(CONFIG_SENSORS_TC74) += tc74.o
obj-$(CONFIG_SENSORS_THMC50) += thmc50.o
diff --git a/drivers/hwmon/sy7636a-hwmon.c b/drivers/hwmon/sy7636a-hwmon.c
new file mode 100644
index 000000000000..6dd9c2a0f0e0
--- /dev/null
+++ b/drivers/hwmon/sy7636a-hwmon.c
@@ -0,0 +1,106 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Functions to access SY3686A power management chip temperature
+ *
+ * Copyright (C) 2021 reMarkable AS - http://www.remarkable.com/
+ *
+ * Authors: Lars Ivar Miljeteig <lars.ivar.miljeteig@xxxxxxxxxxxxxx>
+ * Alistair Francis <alistair@xxxxxxxxxxxxx>
+ */
+
+#include <linux/err.h>
+#include <linux/hwmon.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/regulator/machine.h>
+
+#include <linux/mfd/sy7636a.h>
+
+static int sy7636a_read(struct device *dev, enum hwmon_sensor_types type,
+ u32 attr, int channel, long *temp)
+{
+ struct regmap *regmap = dev_get_drvdata(dev);
+ int ret, reg_val;
+
+ ret = regmap_read(regmap,
+ SY7636A_REG_TERMISTOR_READOUT, ®_val);
+ if (ret)
+ return ret;
+
+ *temp = reg_val * 1000;
+
+ return 0;
+}
+
+static umode_t sy7636a_is_visible(const void *data,
+ enum hwmon_sensor_types type,
+ u32 attr, int channel)
+{
+ if (type != hwmon_temp)
+ return 0;
+
+ if (attr != hwmon_temp_input)
+ return 0;
+
+ return 0444;
+}
+
+static const struct hwmon_ops sy7636a_hwmon_ops = {
+ .is_visible = sy7636a_is_visible,
+ .read = sy7636a_read,
+};
+
+static const struct hwmon_channel_info *sy7636a_info[] = {
+ HWMON_CHANNEL_INFO(chip, HWMON_C_REGISTER_TZ),
+ HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT),
+ NULL
+};
+
+static const struct hwmon_chip_info sy7636a_chip_info = {
+ .ops = &sy7636a_hwmon_ops,
+ .info = sy7636a_info,
+};
+
+static int sy7636a_sensor_probe(struct platform_device *pdev)
+{
+ struct regmap *regmap = dev_get_regmap(pdev->dev.parent, NULL);
+ struct regulator *regulator;
+ struct device *hwmon_dev;
+ int err;
+
+ if (!regmap)
+ return -EPROBE_DEFER;
+
+ regulator = devm_regulator_get(&pdev->dev, "vcom");
+ if (IS_ERR(regulator))
+ return PTR_ERR(regulator);
+
+ err = regulator_enable(regulator);
+ if (err)
+ return err;
+
+ hwmon_dev = devm_hwmon_device_register_with_info(&pdev->dev,
+ "sy7636a_temperature", regmap,
+ &sy7636a_chip_info, NULL);
+
+ if (IS_ERR(hwmon_dev)) {
+ err = PTR_ERR(hwmon_dev);
+ dev_err(&pdev->dev, "Unable to register hwmon device, returned %d\n", err);
+ return err;
+ }
+
+ return 0;
+}
+
+static struct platform_driver sy7636a_sensor_driver = {
+ .probe = sy7636a_sensor_probe,
+ .driver = {
+ .name = "sy7636a-temperature",
+ },
+};
+module_platform_driver(sy7636a_sensor_driver);
+
+MODULE_DESCRIPTION("SY7636A sensor driver");
+MODULE_LICENSE("GPL");
--
2.31.1
