[PATCH v9 08/12] hwmon: sy7636a: Add temperature driver for sy7636a

Alistair Francis
2021-08-06T09:12:00Z

This is a multi-function device to interface with the sy7636a
EPD PMIC chip from Silergy.

Signed-off-by: Alistair Francis <alistair@alistair23.me>
---
arch/arm/configs/imx_v6_v7_defconfig | 1 +
drivers/hwmon/Kconfig | 10 ++++
drivers/hwmon/Makefile | 1 +
drivers/hwmon/sy7636a-hwmon.c | 77 ++++++++++++++++++++++++++++
4 files changed, 89 insertions(+)
create mode 100644 drivers/hwmon/sy7636a-hwmon.c

diff --git a/arch/arm/configs/imx_v6_v7_defconfig b/arch/arm/configs/imx_v6_v7_defconfig
index 477dac1edc75..ef8c6dca1277 100644
--- a/arch/arm/configs/imx_v6_v7_defconfig
+++ b/arch/arm/configs/imx_v6_v7_defconfig
@@ -229,6 +229,7 @@ CONFIG_RN5T618_POWER=m
CONFIG_SENSORS_MC13783_ADC=y
CONFIG_SENSORS_GPIO_FAN=y
CONFIG_SENSORS_IIO_HWMON=y
+CONFIG_SENSORS_SY7636A=y
CONFIG_THERMAL_STATISTICS=y
CONFIG_THERMAL_WRITABLE_TRIPS=y
CONFIG_CPU_THERMAL=y
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index e3675377bc5d..6cae12de59cd 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -1631,6 +1631,16 @@ 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"
+ depends on I2C
+ 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 d712c61c1f5e..8b2e09e25b24 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -180,6 +180,7 @@ 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..0f4618e24d71
--- /dev/null
+++ b/drivers/hwmon/sy7636a-hwmon.c
@@ -0,0 +1,77 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Functions to access SY3686A power management chip temperature
+ *
+ * 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/init.h>
+#include <linux/slab.h>
+#include <linux/jiffies.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/err.h>
+#include <linux/sysfs.h>
+#include <linux/platform_device.h>
+
+#include <linux/mfd/sy7636a.h>
+
+static ssize_t show_temp(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ unsigned int reg_val;
+ int ret;
+ struct regmap *regmap = dev_get_drvdata(dev);
+
+ ret = regmap_read(regmap,
+ SY7636A_REG_TERMISTOR_READOUT, &reg_val);
+ if (ret)
+ return ret;
+
+ return snprintf(buf, PAGE_SIZE, "%d\n", reg_val);
+}
+
+static SENSOR_DEVICE_ATTR(temp0, 0444, show_temp, NULL, 0);
+
+static struct attribute *sy7636a_attrs[] = {
+ &sensor_dev_attr_temp0.dev_attr.attr,
+ NULL
+};
+
+ATTRIBUTE_GROUPS(sy7636a);
+
+static int sy7636a_sensor_probe(struct platform_device *pdev)
+{
+ struct regmap *regmap = dev_get_drvdata(pdev->dev.parent);
+ struct device *hwmon_dev;
+ int err;
+
+ if (!regmap)
+ return -EPROBE_DEFER;
+
+ hwmon_dev = devm_hwmon_device_register_with_groups(&pdev->dev,
+ "sy7636a_temperature", regmap, sy7636a_groups);
+
+ if (IS_ERR(hwmon_dev)) {
+ err = PTR_ERR(hwmon_dev);
+ dev_err(&pdev->dev, "Unable to register hwmon device, returned %d", 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