hwmon: (w83793) VID and VRM handling cleanups

* Rework the device initialization function so as to read the
"Multi-Function Pin Control" register (0x58) once instead of twice.
I2C transactions aren't cheap so this speeds up the driver loading.

* Only create the "vrm" attribute if at least one VID value is
available.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Gong Jun <jgong@winbond.com>
Acked-by: Rudolf Marek <r.marek@assembler.cz>
Signed-off-by: Mark M. Hoffman <mhoffman@lightlink.com>

1 files changed, 14 insertions, 12 deletions

diff --git a/drivers/hwmon/w83793.c b/drivers/hwmon/w83793.c
index ee35af93b574..ed3c019b78c7 100644
--- a/drivers/hwmon/w83793.c
+++ b/drivers/hwmon/w83793.c
@@ -1024,10 +1024,9 @@ static struct sensor_device_attribute_2 w83793_vid[] = {
         SENSOR_ATTR_2(cpu0_vid, S_IRUGO, show_vid, NULL, NOT_USED, 0),
         SENSOR_ATTR_2(cpu1_vid, S_IRUGO, show_vid, NULL, NOT_USED, 1),
 };
+static DEVICE_ATTR(vrm, S_IWUSR | S_IRUGO, show_vrm, store_vrm);
 
 static struct sensor_device_attribute_2 sda_single_files[] = {
-        SENSOR_ATTR_2(vrm, S_IWUSR | S_IRUGO, show_vrm, store_vrm,
-                      NOT_USED, NOT_USED),
         SENSOR_ATTR_2(chassis, S_IWUSR | S_IRUGO, show_alarm_beep,
                       store_chassis_clear, ALARM_STATUS, 30),
         SENSOR_ATTR_2(beep_enable, S_IWUSR | S_IRUGO, show_beep_enable,
@@ -1080,6 +1079,7 @@ static int w83793_detach_client(struct i2c_client *client)
 
                 for (i = 0; i < ARRAY_SIZE(w83793_vid); i++)
                         device_remove_file(dev, &w83793_vid[i].dev_attr);
+                device_remove_file(dev, &dev_attr_vrm);
 
                 for (i = 0; i < ARRAY_SIZE(w83793_left_fan); i++)
                         device_remove_file(dev, &w83793_left_fan[i].dev_attr);
@@ -1282,7 +1282,6 @@ static int w83793_detect(struct i2c_adapter *adapter, int address, int kind)
         /* Initialize the chip */
         w83793_init_client(client);
 
-        data->vrm = vid_which_vrm();
         /*
            Only fan 1-5 has their own input pins,
            Pwm 1-3 has their own pins
@@ -1293,7 +1292,9 @@ static int w83793_detect(struct i2c_adapter *adapter, int address, int kind)
         val = w83793_read_value(client, W83793_REG_FANIN_CTRL);
 
         /* check the function of pins 49-56 */
-        if (!(tmp & 0x80)) {
+        if (tmp & 0x80) {
+                data->has_vid |= 0x2;   /* has VIDB */
+        } else {
                 data->has_pwm |= 0x18;  /* pwm 4,5 */
                 if (val & 0x01) {       /* fan 6 */
                         data->has_fan |= 0x20;
@@ -1309,13 +1310,15 @@ static int w83793_detect(struct i2c_adapter *adapter, int address, int kind)
                 }
         }
 
+        /* check the function of pins 37-40 */
+        if (!(tmp & 0x29))
+                data->has_vid |= 0x1;   /* has VIDA */
         if (0x08 == (tmp & 0x0c)) {
                 if (val & 0x08) /* fan 9 */
                         data->has_fan |= 0x100;
                 if (val & 0x10) /* fan 10 */
                         data->has_fan |= 0x200;
         }
-
         if (0x20 == (tmp & 0x30)) {
                 if (val & 0x20) /* fan 11 */
                         data->has_fan |= 0x400;
@@ -1359,13 +1362,6 @@ static int w83793_detect(struct i2c_adapter *adapter, int address, int kind)
         if (tmp & 0x02)
                 data->has_temp |= 0x20;
 
-        /* Detect the VID usage and ignore unused input */
-        tmp = w83793_read_value(client, W83793_REG_MFC);
-        if (!(tmp & 0x29))
-                data->has_vid |= 0x1;   /* has VIDA */
-        if (tmp & 0x80)
-                data->has_vid |= 0x2;   /* has VIDB */
-
         /* Register sysfs hooks */
         for (i = 0; i < ARRAY_SIZE(w83793_sensor_attr_2); i++) {
                 err = device_create_file(dev,
@@ -1381,6 +1377,12 @@ static int w83793_detect(struct i2c_adapter *adapter, int address, int kind)
                 if (err)
                         goto exit_remove;
         }
+        if (data->has_vid) {
+                data->vrm = vid_which_vrm();
+                err = device_create_file(dev, &dev_attr_vrm);
+                if (err)
+                        goto exit_remove;
+        }
 
         for (i = 0; i < ARRAY_SIZE(sda_single_files); i++) {
                 err = device_create_file(dev, &sda_single_files[i].dev_attr);