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-rw-r--r--drivers/hwmon/sy7636a-hwmon.c106
1 files changed, 106 insertions, 0 deletions
diff --git a/drivers/hwmon/sy7636a-hwmon.c b/drivers/hwmon/sy7636a-hwmon.c
new file mode 100644
index 000000000..6dd9c2a0f
--- /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@remarkable.com>
+ * Alistair Francis <alistair@alistair23.me>
+ */
+
+#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, &reg_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");