hwmon: (w83795) Add support for dynamic in0-2 limits
The W83795G can be configured to set the in0, in1 and/or in2 voltage
limits dynamically based on VID input pins. Switch the respective
sysfs attributes to read-only.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
diff --git a/drivers/hwmon/w83795.c b/drivers/hwmon/w83795.c
index 24e4424..458fb29 100644
--- a/drivers/hwmon/w83795.c
+++ b/drivers/hwmon/w83795.c
@@ -316,6 +316,7 @@
u8 bank;
u32 has_in; /* Enable monitor VIN or not */
+ u8 has_dyn_in; /* Only in2-0 can have this */
u16 in[21][3]; /* Register value, read/high/low */
u8 in_lsb[10][3]; /* LSB Register value, high/low */
u8 has_gain; /* has gain: in17-20 * 8 */
@@ -450,6 +451,23 @@
data->in[i][IN_READ] = tmp;
}
+ /* in0-2 can have dynamic limits (W83795G only) */
+ if (data->has_dyn_in) {
+ u8 lsb_max = w83795_read(client, IN_LSB_REG(0, IN_MAX));
+ u8 lsb_low = w83795_read(client, IN_LSB_REG(0, IN_LOW));
+
+ for (i = 0; i < 3; i++) {
+ if (!(data->has_dyn_in & (1 << i)))
+ continue;
+ data->in[i][IN_MAX] =
+ w83795_read(client, W83795_REG_IN[i][IN_MAX]);
+ data->in[i][IN_LOW] =
+ w83795_read(client, W83795_REG_IN[i][IN_LOW]);
+ data->in_lsb[i][IN_MAX] = (lsb_max >> (2 * i)) & 0x03;
+ data->in_lsb[i][IN_LOW] = (lsb_low >> (2 * i)) & 0x03;
+ }
+ }
+
/* Update fan */
for (i = 0; i < ARRAY_SIZE(data->fan); i++) {
if (!(data->has_fan & (1 << i)))
@@ -1450,6 +1468,8 @@
#define NOT_USED -1
+/* Don't change the attribute order, _max and _min are accessed by index
+ * somewhere else in the code */
#define SENSOR_ATTR_IN(index) { \
SENSOR_ATTR_2(in##index##_input, S_IRUGO, show_in, NULL, \
IN_READ, index), \
@@ -1844,6 +1864,39 @@
return 0;
}
+static void w83795_check_dynamic_in_limits(struct i2c_client *client)
+{
+ struct w83795_data *data = i2c_get_clientdata(client);
+ u8 vid_ctl;
+ int i, err_max, err_min;
+
+ vid_ctl = w83795_read(client, W83795_REG_VID_CTRL);
+
+ /* Return immediately if VRM isn't configured */
+ if ((vid_ctl & 0x07) == 0x00 || (vid_ctl & 0x07) == 0x07)
+ return;
+
+ data->has_dyn_in = (vid_ctl >> 3) & 0x07;
+ for (i = 0; i < 2; i++) {
+ if (!(data->has_dyn_in & (1 << i)))
+ continue;
+
+ /* Voltage limits in dynamic mode, switch to read-only */
+ err_max = sysfs_chmod_file(&client->dev.kobj,
+ &w83795_in[i][2].dev_attr.attr,
+ S_IRUGO);
+ err_min = sysfs_chmod_file(&client->dev.kobj,
+ &w83795_in[i][3].dev_attr.attr,
+ S_IRUGO);
+ if (err_max || err_min)
+ dev_warn(&client->dev, "Failed to set in%d limits "
+ "read-only (%d, %d)\n", i, err_max, err_min);
+ else
+ dev_info(&client->dev, "in%d limits set dynamically "
+ "from VID\n", i);
+ }
+}
+
/* Check pins that can be used for either temperature or voltage monitoring */
static void w83795_apply_temp_config(struct w83795_data *data, u8 config,
int temp_chan, int in_chan)
@@ -2049,6 +2102,9 @@
if (err)
goto exit_remove;
+ if (data->chip_type == w83795g)
+ w83795_check_dynamic_in_limits(client);
+
data->hwmon_dev = hwmon_device_register(dev);
if (IS_ERR(data->hwmon_dev)) {
err = PTR_ERR(data->hwmon_dev);