On 15/10/2021 14:25, Alistair Francis wrote:

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

As it is an initial submission, could you give a brief description of
the sensor even if it is very simple ?

no deps ?

2021

+ *
+ * Authors: Lars Ivar Miljeteig [off-list ref]
+ *          Alistair Francis [off-list ref]
+ */

From Documentation/process/submitting-drivers.rst

"""
Copyright:
                The copyright owner must agree to use of GPL.
                It's best if the submitter and copyright owner
                are the same person/entity. If not, the name of
                the person/entity authorizing use of GPL should be
                listed in case it's necessary to verify the will of
                the copyright owner.
"""

[Cc'ed Lars Ivar Miljeteig]

+#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)

...(struct thermal_zone_device *tz, int *temp)

+{
+	unsigned int mode_ctr;
+	int ret, reg_val;
+	struct regmap *regmap = arg;
+	bool isVoltageActive;

Looks like c++ code

+	ret = regmap_read(regmap,
+			SY7636A_REG_OPERATION_MODE_CRL, &mode_ctr);
+	if (ret)
+		return ret;
+
+	isVoltageActive = mode_ctr & SY7636A_OPERATION_MODE_CRL_ONOFF;
+
+	/* If operation mode isn't set to control, then let's set it. */
+	if (!isVoltageActive) {
+		ret = regmap_write(regmap,
+				SY7636A_REG_OPERATION_MODE_CRL,
+				mode_ctr | SY7636A_OPERATION_MODE_CRL_ONOFF);
+		if (ret)
+			return ret;
+	}

Who is turnning off the 'control' outside of this driver?

+	ret = regmap_read(regmap,
+			SY7636A_REG_TERMISTOR_READOUT, &reg_val);
+	if (ret)
+		return ret;
+
+	/* Restore the operation mode if it wasn't set */
+	if (!isVoltageActive) {
+		ret = regmap_write(regmap,
+				SY7636A_REG_OPERATION_MODE_CRL,
+				mode_ctr);
+		if (ret)
+			return ret;
+	}

IIUC, this is a mfd, so if a component outside of this driver is
touching this SY7636A_REG_OPERATION_MODE_CRL, there is no guarantee
these operations will stay consistent.

Is that correct ?

+	*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_regmap(pdev->dev.parent, NULL);
+	struct thermal_zone_device *thermal_zone_dev;

regmap return value check, please

+	thermal_zone_dev = devm_thermal_zone_of_sensor_register(
+			pdev->dev.parent,
+			0,
+			regmap,
+			&ops);

Fix indent please

+
+	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 [off-list ref]");
+MODULE_DESCRIPTION("SY7636A thermal driver");
+MODULE_LICENSE("GPL v2");

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