[PATCH 2/4] platform/x86: (ayn-ec) Add Temperature Sensors

["Derek J. Clark" <derekjohn.clark@gmail.com>]

Adds temperature sensors to the ayn-ec hwmon interface. These read-only
values include Battery, Motherboard, Charger IC, vCore, and CPU Core, as
well as labels for each entry. The temperature values provided by the EC
are whole numbers in degrees Celsius. As hwmon expects millidegrees, we
scale the raw value up.

`sensors` output after this patch is applied:
aynec-isa-0000
Adapter: ISA adapter
fan1:        1876 RPM
Battery:      +29.0°C
Motherboard:  +30.0°C
Charger IC:   +30.0°C
vCore:        +36.0°C
CPU Core:     +48.0°C

Signed-off-by: Derek J. Clark <derekjohn.clark@gmail.com>
---
 drivers/platform/x86/ayn-ec.c | 89 +++++++++++++++++++++++++++++++++++
 1 file changed, 89 insertions(+)

diff --git a/drivers/platform/x86/ayn-ec.c b/drivers/platform/x86/ayn-ec.c
index 06f232bd10fa..b2054dc2358a 100644
--- a/drivers/platform/x86/ayn-ec.c
+++ b/drivers/platform/x86/ayn-ec.c
@@ -50,8 +50,16 @@
 #define AYN_SENSOR_PWM_FAN_TEMP_4_REG	0x19
 #define AYN_SENSOR_PWM_FAN_TEMP_5_REG	0x1B
 
+/* EC Teperature Sensors */
+#define AYN_SENSOR_BAT_TEMP_REG		0x04 /* Battery */
+#define AYN_SENSOR_CHARGE_TEMP_REG	0x07 /* Charger IC */
+#define AYN_SENSOR_MB_TEMP_REG		0x05 /* Motherboard */
+#define AYN_SENSOR_PROC_TEMP_REG	0x09 /* CPU Core */
+#define AYN_SENSOR_VCORE_TEMP_REG	0x08 /* vCore */
+
 /* Handle ACPI lock mechanism */
 #define ACPI_LOCK_DELAY_MS 500
+
 enum ayn_model {
 	ayn_loki_max = 1,
 	ayn_loki_minipro,
@@ -63,6 +71,20 @@ struct ayn_device {
 	u32 ayn_lock; /* ACPI EC Lock */
 } drvdata;
 
+struct thermal_sensor {
+	char *name;
+	int reg;
+};
+
+static struct thermal_sensor thermal_sensors[] = {
+	{ "Battery", AYN_SENSOR_BAT_TEMP_REG },
+	{ "Motherboard", AYN_SENSOR_MB_TEMP_REG },
+	{ "Charger IC", AYN_SENSOR_CHARGE_TEMP_REG },
+	{ "vCore", AYN_SENSOR_VCORE_TEMP_REG },
+	{ "CPU Core", AYN_SENSOR_PROC_TEMP_REG },
+	{}
+};
+
 /* Handle ACPI lock mechanism */
 #define ACPI_LOCK_DELAY_MS 500
 
@@ -503,6 +525,63 @@ static SENSOR_DEVICE_ATTR_RW(pwm1_auto_point3_temp, pwm_curve, 7);
 static SENSOR_DEVICE_ATTR_RW(pwm1_auto_point4_temp, pwm_curve, 8);
 static SENSOR_DEVICE_ATTR_RW(pwm1_auto_point5_temp, pwm_curve, 9);
 
+/**
+ * thermal_sensor_show() - Read a thermal sensor attribute value.
+ *
+ * @dev: The attribute's parent device.
+ * @attr: The attribute to read.
+ * @buf: Buffer to read to.
+ *
+ * Return: Number of bytes read, or an error.
+ */
+static ssize_t thermal_sensor_show(struct device *dev,
+				   struct device_attribute *attr, char *buf)
+{
+	long ret, val;
+	int i;
+
+	i = to_sensor_dev_attr(attr)->index;
+
+	ret = read_from_ec(thermal_sensors[i].reg, 1, &val);
+	if (ret)
+		return ret;
+
+	val = val * 1000L;
+
+	return sysfs_emit(buf, "%ld\n", val);
+}
+
+/**
+ * thermal_sensor_label_show() - Read a thermal sensor attribute label.
+ *
+ * @dev: The attribute's parent device.
+ * @attr: The attribute to read.
+ * @buf: Buffer to read to.
+ *
+ * Return: Number of bytes read, or an error.
+ */
+static ssize_t thermal_sensor_label_show(struct device *dev,
+					 struct device_attribute *attr,
+					 char *buf)
+{
+	int i;
+
+	i = to_sensor_dev_attr(attr)->index;
+
+	return sysfs_emit(buf, "%s\n", thermal_sensors[i].name);
+}
+
+static SENSOR_DEVICE_ATTR_RO(temp1_input, thermal_sensor, 0);
+static SENSOR_DEVICE_ATTR_RO(temp2_input, thermal_sensor, 1);
+static SENSOR_DEVICE_ATTR_RO(temp3_input, thermal_sensor, 2);
+static SENSOR_DEVICE_ATTR_RO(temp4_input, thermal_sensor, 3);
+static SENSOR_DEVICE_ATTR_RO(temp5_input, thermal_sensor, 4);
+static SENSOR_DEVICE_ATTR_RO(temp1_label, thermal_sensor_label, 0);
+static SENSOR_DEVICE_ATTR_RO(temp2_label, thermal_sensor_label, 1);
+static SENSOR_DEVICE_ATTR_RO(temp3_label, thermal_sensor_label, 2);
+static SENSOR_DEVICE_ATTR_RO(temp4_label, thermal_sensor_label, 3);
+static SENSOR_DEVICE_ATTR_RO(temp5_label, thermal_sensor_label, 4);
+
 static struct attribute *ayn_sensors_attrs[] = {
 	&sensor_dev_attr_pwm1_auto_point1_pwm.dev_attr.attr,
 	&sensor_dev_attr_pwm1_auto_point1_temp.dev_attr.attr,
@@ -514,6 +593,16 @@ static struct attribute *ayn_sensors_attrs[] = {
 	&sensor_dev_attr_pwm1_auto_point4_temp.dev_attr.attr,
 	&sensor_dev_attr_pwm1_auto_point5_pwm.dev_attr.attr,
 	&sensor_dev_attr_pwm1_auto_point5_temp.dev_attr.attr,
+	&sensor_dev_attr_temp1_input.dev_attr.attr,
+	&sensor_dev_attr_temp1_label.dev_attr.attr,
+	&sensor_dev_attr_temp2_input.dev_attr.attr,
+	&sensor_dev_attr_temp2_label.dev_attr.attr,
+	&sensor_dev_attr_temp3_input.dev_attr.attr,
+	&sensor_dev_attr_temp3_label.dev_attr.attr,
+	&sensor_dev_attr_temp4_input.dev_attr.attr,
+	&sensor_dev_attr_temp4_label.dev_attr.attr,
+	&sensor_dev_attr_temp5_input.dev_attr.attr,
+	&sensor_dev_attr_temp5_label.dev_attr.attr,
 	NULL,
 };
 
-- 
2.50.0