[PATCH v9 07/12] thermal: sy7636a: Add thermal driver for sy7636a

Alistair Francis
2021-08-06T09:11:56Z

Add thermal driver to enable kernel based polling
and shutdown of device for temperatures out of spec

Signed-off-by: Alistair Francis <alistair@alistair23.me>
---
drivers/thermal/Kconfig | 6 ++
drivers/thermal/Makefile | 1 +
drivers/thermal/sy7636a_thermal.c | 91 +++++++++++++++++++++++++++++++
3 files changed, 98 insertions(+)
create mode 100644 drivers/thermal/sy7636a_thermal.c

diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
index d7f44deab5b1..6ee0e7de1b37 100644
--- a/drivers/thermal/Kconfig
+++ b/drivers/thermal/Kconfig
@@ -450,6 +450,12 @@ depends on (ARCH_STI || ARCH_STM32) && OF
source "drivers/thermal/st/Kconfig"
endmenu

+config SY7636A_THERMAL
+ tristate "SY7636A thermal management"
+ help
+ Enable the sy7636a thermal driver, which supports the
+ temperature sensor embedded in Silabs SY7636A IC.
+
source "drivers/thermal/tegra/Kconfig"

config GENERIC_ADC_THERMAL
diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
index 82fc3e616e54..2e1aca8a0a09 100644
--- a/drivers/thermal/Makefile
+++ b/drivers/thermal/Makefile
@@ -51,6 +51,7 @@ obj-$(CONFIG_DA9062_THERMAL) += da9062-thermal.o
obj-y += intel/
obj-$(CONFIG_TI_SOC_THERMAL) += ti-soc-thermal/
obj-y += st/
+obj-$(CONFIG_SY7636A_THERMAL) += sy7636a_thermal.o
obj-$(CONFIG_QCOM_TSENS) += qcom/
obj-y += tegra/
obj-$(CONFIG_HISI_THERMAL) += hisi_thermal.o
diff --git a/drivers/thermal/sy7636a_thermal.c b/drivers/thermal/sy7636a_thermal.c
new file mode 100644
index 000000000000..4e41ae78d11c
--- /dev/null
+++ b/drivers/thermal/sy7636a_thermal.c
@@ -0,0 +1,91 @@
+// 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/platform_device.h>
+#include <linux/thermal.h>
+
+#include <linux/mfd/sy7636a.h>
+
+static int sy7636a_get_temp(void *arg, int *res)
+{
+ unsigned int reg_val, mode_ctr;
+ int ret;
+ struct regmap *regmap = arg;
+ bool isVoltageActive;
+
+ ret = regmap_read(regmap,
+ SY7636A_REG_OPERATION_MODE_CRL, &mode_ctr);
+ if (ret)
+ return ret;
+
+ isVoltageActive = mode_ctr & SY7636A_OPERATION_MODE_CRL_ONOFF;
+
+ if (!isVoltageActive) {
+ ret = regmap_write(regmap,
+ SY7636A_REG_OPERATION_MODE_CRL,
+ mode_ctr | SY7636A_OPERATION_MODE_CRL_ONOFF);
+ if (ret)
+ return ret;
+ }
+
+ ret = regmap_read(regmap,
+ SY7636A_REG_TERMISTOR_READOUT, &reg_val);
+ if (ret)
+ return ret;
+
+ if (!isVoltageActive) {
+ ret = regmap_write(regmap,
+ SY7636A_REG_OPERATION_MODE_CRL,
+ mode_ctr);
+ if (ret)
+ return ret;
+ }
+
+ *res = reg_val * 1000;
+
+ return ret;
+}
+
+static const struct thermal_zone_of_device_ops ops = {
+ .get_temp = sy7636a_get_temp,
+};
+
+static int sy7636a_thermal_probe(struct platform_device *pdev)
+{
+ struct regmap *regmap = dev_get_drvdata(pdev->dev.parent);
+ struct thermal_zone_device *thermal_zone_dev;
+
+ thermal_zone_dev = devm_thermal_zone_of_sensor_register(
+ pdev->dev.parent,
+ 0,
+ regmap,
+ &ops);
+
+ return PTR_ERR_OR_ZERO(thermal_zone_dev);
+}
+
+static const struct platform_device_id sy7636a_thermal_id_table[] = {
+ { "sy7636a-thermal", },
+ { }
+};
+MODULE_DEVICE_TABLE(platform, sy7636a_thermal_id_table);
+
+static struct platform_driver sy7636a_thermal_driver = {
+ .driver = {
+ .name = "sy7636a-thermal",
+ },
+ .probe = sy7636a_thermal_probe,
+ .id_table = sy7636a_thermal_id_table,
+};
+module_platform_driver(sy7636a_thermal_driver);
+
+MODULE_AUTHOR("Lars Ivar Miljeteig <lars.ivar.miljeteig@remarkable.com>");
+MODULE_DESCRIPTION("SY7636A thermal driver");
+MODULE_LICENSE("GPL v2");
--
2.31.1