hwmon: (w83795) List all usable temperature sources

Temperature sources are not correlated directly with temperature
channels. A look-up table is required to find out which temperature
sources can be used depending on which temperature channels (both
analog and digital) are enabled.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Guenter Roeck <guenter.roeck@ericsson.com>

drivers/hwmon/w83795.c

@@ -178,6 +178,14 @@ static const u8 IN_LSB_SHIFT_IDX[][2] = {
 
 #define W83795_REG_TSS(index)		(0x209 + (index))
 
+#define TSS_MAP_RESERVED		0xff
+static const u8 tss_map[4][6] = {
+	{ 0,  1,  2,  3,  4,  5},
+	{ 6,  7,  8,  9,  0,  1},
+	{10, 11, 12, 13,  2,  3},
+	{ 4,  5,  4,  5, TSS_MAP_RESERVED, TSS_MAP_RESERVED},
+};
+
 #define PWM_OUTPUT			0
 #define PWM_FREQ			1
 #define PWM_START			2
@@ -930,6 +938,27 @@ show_pwm_mode(struct device *dev, struct device_attribute *attr, char *buf)
 	return sprintf(buf, "%u\n", mode);
 }
 
+/*
+ * Check whether a given temperature source can ever be useful.
+ * Returns the number of selectable temperature channels which are
+ * enabled.
+ */
+static int w83795_tss_useful(const struct w83795_data *data, int tsrc)
+{
+	int useful = 0, i;
+
+	for (i = 0; i < 4; i++) {
+		if (tss_map[i][tsrc] == TSS_MAP_RESERVED)
+			continue;
+		if (tss_map[i][tsrc] < 6)	/* Analog */
+			useful += (data->has_temp >> tss_map[i][tsrc]) & 1;
+		else				/* Digital */
+			useful += (data->has_dts >> (tss_map[i][tsrc] - 6)) & 1;
+	}
+
+	return useful;
+}
+
 static ssize_t
 show_temp_src(struct device *dev, struct device_attribute *attr, char *buf)
 {
@@ -1608,8 +1637,6 @@ store_sf_setup(struct device *dev, struct device_attribute *attr,
 	SENSOR_ATTR_2(temp##index##_beep, S_IWUSR | S_IRUGO,		\
 		show_alarm_beep, store_beep, BEEP_ENABLE,		\
 		index + (index > 4 ? 11 : 17)),				\
-	SENSOR_ATTR_2(temp##index##_source_sel, S_IWUSR | S_IRUGO,	\
-		show_temp_src, store_temp_src, NOT_USED, index - 1),	\
 	SENSOR_ATTR_2(temp##index##_pwm_enable, S_IWUSR | S_IRUGO,	\
 		show_temp_pwm_enable, store_temp_pwm_enable,		\
 		TEMP_PWM_ENABLE, index - 1),				\
@@ -1695,7 +1722,7 @@ static const struct sensor_device_attribute_2 w83795_fan[][4] = {
 	SENSOR_ATTR_FAN(14),
 };
 
-static const struct sensor_device_attribute_2 w83795_temp[][29] = {
+static const struct sensor_device_attribute_2 w83795_temp[][28] = {
 	SENSOR_ATTR_TEMP(1),
 	SENSOR_ATTR_TEMP(2),
 	SENSOR_ATTR_TEMP(3),
@@ -1726,6 +1753,21 @@ static const struct sensor_device_attribute_2 w83795_pwm[][8] = {
 	SENSOR_ATTR_PWM(8),
 };
 
+static const struct sensor_device_attribute_2 w83795_tss[6] = {
+	SENSOR_ATTR_2(temp1_source_sel, S_IWUSR | S_IRUGO,
+		      show_temp_src, store_temp_src, NOT_USED, 0),
+	SENSOR_ATTR_2(temp2_source_sel, S_IWUSR | S_IRUGO,
+		      show_temp_src, store_temp_src, NOT_USED, 1),
+	SENSOR_ATTR_2(temp3_source_sel, S_IWUSR | S_IRUGO,
+		      show_temp_src, store_temp_src, NOT_USED, 2),
+	SENSOR_ATTR_2(temp4_source_sel, S_IWUSR | S_IRUGO,
+		      show_temp_src, store_temp_src, NOT_USED, 3),
+	SENSOR_ATTR_2(temp5_source_sel, S_IWUSR | S_IRUGO,
+		      show_temp_src, store_temp_src, NOT_USED, 4),
+	SENSOR_ATTR_2(temp6_source_sel, S_IWUSR | S_IRUGO,
+		      show_temp_src, store_temp_src, NOT_USED, 5),
+};
+
 static const struct sensor_device_attribute_2 sda_single_files[] = {
 	SENSOR_ATTR_2(intrusion0_alarm, S_IWUSR | S_IRUGO, show_alarm_beep,
 		      store_chassis_clear, ALARM_STATUS, 46),
@@ -1890,6 +1932,15 @@ static int w83795_handle_files(struct device *dev, int (*fn)(struct device *,
 		}
 	}
 
+	for (i = 0; i < ARRAY_SIZE(w83795_tss); i++) {
+		j = w83795_tss_useful(data, i);
+		if (!j)
+			continue;
+		err = fn(dev, &w83795_tss[i].dev_attr);
+		if (err)
+			return err;
+	}
+
 	for (i = 0; i < ARRAY_SIZE(sda_single_files); i++) {
 		err = fn(dev, &sda_single_files[i].dev_attr);
 		if (err)