hwmon/f71805f: Support DC fan speed control mode

In DC mode, the pwmN_freq files are not created.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
diff --git a/drivers/hwmon/f71805f.c b/drivers/hwmon/f71805f.c
index 173e2d2..29a3984 100644
--- a/drivers/hwmon/f71805f.c
+++ b/drivers/hwmon/f71805f.c
@@ -126,6 +126,7 @@
 
 /* individual register bits */
 #define FAN_CTRL_SKIP			0x80
+#define FAN_CTRL_DC_MODE		0x10
 #define FAN_CTRL_MODE_MASK		0x03
 #define FAN_CTRL_MODE_SPEED		0x00
 #define FAN_CTRL_MODE_TEMPERATURE	0x01
@@ -233,6 +234,11 @@
 		return 1000000UL / (val << 8);
 }
 
+static inline int pwm_mode_from_reg(u8 reg)
+{
+	return !(reg & FAN_CTRL_DC_MODE);
+}
+
 static inline long temp_from_reg(u8 reg)
 {
 	return (reg * 1000);
@@ -562,6 +568,16 @@
 	return sprintf(buf, "%lu\n", pwm_freq_from_reg(data->pwm_freq[nr]));
 }
 
+static ssize_t show_pwm_mode(struct device *dev, struct device_attribute
+			     *devattr, char *buf)
+{
+	struct f71805f_data *data = f71805f_update_device(dev);
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+	int nr = attr->index;
+
+	return sprintf(buf, "%d\n", pwm_mode_from_reg(data->fan_ctrl[nr]));
+}
+
 static ssize_t set_pwm(struct device *dev, struct device_attribute *devattr,
 		       const char *buf, size_t count)
 {
@@ -839,16 +855,19 @@
 			  show_pwm_enable, set_pwm_enable, 0);
 static SENSOR_DEVICE_ATTR(pwm1_freq, S_IRUGO | S_IWUSR,
 			  show_pwm_freq, set_pwm_freq, 0);
+static SENSOR_DEVICE_ATTR(pwm1_mode, S_IRUGO, show_pwm_mode, NULL, 0);
 static SENSOR_DEVICE_ATTR(pwm2, S_IRUGO, show_pwm, set_pwm, 1);
 static SENSOR_DEVICE_ATTR(pwm2_enable, S_IRUGO | S_IWUSR,
 			  show_pwm_enable, set_pwm_enable, 1);
 static SENSOR_DEVICE_ATTR(pwm2_freq, S_IRUGO | S_IWUSR,
 			  show_pwm_freq, set_pwm_freq, 1);
+static SENSOR_DEVICE_ATTR(pwm2_mode, S_IRUGO, show_pwm_mode, NULL, 1);
 static SENSOR_DEVICE_ATTR(pwm3, S_IRUGO, show_pwm, set_pwm, 2);
 static SENSOR_DEVICE_ATTR(pwm3_enable, S_IRUGO | S_IWUSR,
 			  show_pwm_enable, set_pwm_enable, 2);
 static SENSOR_DEVICE_ATTR(pwm3_freq, S_IRUGO | S_IWUSR,
 			  show_pwm_freq, set_pwm_freq, 2);
+static SENSOR_DEVICE_ATTR(pwm3_mode, S_IRUGO, show_pwm_mode, NULL, 2);
 
 static SENSOR_DEVICE_ATTR(in0_alarm, S_IRUGO, show_alarm, NULL, 0);
 static SENSOR_DEVICE_ATTR(in1_alarm, S_IRUGO, show_alarm, NULL, 1);
@@ -944,7 +963,7 @@
 		&sensor_dev_attr_fan1_alarm.dev_attr.attr,
 		&sensor_dev_attr_pwm1.dev_attr.attr,
 		&sensor_dev_attr_pwm1_enable.dev_attr.attr,
-		&sensor_dev_attr_pwm1_freq.dev_attr.attr,
+		&sensor_dev_attr_pwm1_mode.dev_attr.attr,
 		NULL
 	}, {
 		&sensor_dev_attr_fan2_input.dev_attr.attr,
@@ -952,7 +971,7 @@
 		&sensor_dev_attr_fan2_alarm.dev_attr.attr,
 		&sensor_dev_attr_pwm2.dev_attr.attr,
 		&sensor_dev_attr_pwm2_enable.dev_attr.attr,
-		&sensor_dev_attr_pwm2_freq.dev_attr.attr,
+		&sensor_dev_attr_pwm2_mode.dev_attr.attr,
 		NULL
 	}, {
 		&sensor_dev_attr_fan3_input.dev_attr.attr,
@@ -960,7 +979,7 @@
 		&sensor_dev_attr_fan3_alarm.dev_attr.attr,
 		&sensor_dev_attr_pwm3.dev_attr.attr,
 		&sensor_dev_attr_pwm3_enable.dev_attr.attr,
-		&sensor_dev_attr_pwm3_freq.dev_attr.attr,
+		&sensor_dev_attr_pwm3_mode.dev_attr.attr,
 		NULL
 	}
 };
@@ -971,6 +990,19 @@
 	{ .attrs = f71805f_attributes_fan[2] },
 };
 
+/* We don't include pwm_freq files in the arrays above, because they must be
+   created conditionally (only if pwm_mode is 1 == PWM) */
+static struct attribute *f71805f_attributes_pwm_freq[] = {
+	&sensor_dev_attr_pwm1_freq.dev_attr.attr,
+	&sensor_dev_attr_pwm2_freq.dev_attr.attr,
+	&sensor_dev_attr_pwm3_freq.dev_attr.attr,
+	NULL
+};
+
+static const struct attribute_group f71805f_group_pwm_freq = {
+	.attrs = f71805f_attributes_pwm_freq,
+};
+
 /* We also need an indexed access to pwmN files to toggle writability */
 static struct attribute *f71805f_attr_pwm[] = {
 	&sensor_dev_attr_pwm1.dev_attr.attr,
@@ -1034,6 +1066,12 @@
 		if ((err = sysfs_create_group(&pdev->dev.kobj,
 					      &f71805f_group_fan[i])))
 			goto exit_remove_files;
+		/* If control mode is PWM, create pwm_freq file */
+		if (!(data->fan_ctrl[i] & FAN_CTRL_DC_MODE)) {
+			if ((err = sysfs_create_file(&pdev->dev.kobj,
+					f71805f_attributes_pwm_freq[i])))
+				goto exit_remove_files;
+		}
 		/* If PWM is in manual mode, add write permission */
 		if (data->fan_ctrl[i] & FAN_CTRL_MODE_MANUAL) {
 			if ((err = sysfs_chmod_file(&pdev->dev.kobj,
@@ -1059,6 +1097,7 @@
 	sysfs_remove_group(&pdev->dev.kobj, &f71805f_group);
 	for (i = 0; i < 3; i++)
 		sysfs_remove_group(&pdev->dev.kobj, &f71805f_group_fan[i]);
+	sysfs_remove_group(&pdev->dev.kobj, &f71805f_group_pwm_freq);
 exit_free:
 	platform_set_drvdata(pdev, NULL);
 	kfree(data);
@@ -1076,6 +1115,7 @@
 	sysfs_remove_group(&pdev->dev.kobj, &f71805f_group);
 	for (i = 0; i < 3; i++)
 		sysfs_remove_group(&pdev->dev.kobj, &f71805f_group_fan[i]);
+	sysfs_remove_group(&pdev->dev.kobj, &f71805f_group_pwm_freq);
 	kfree(data);
 
 	return 0;