1 files changed, 36 insertions, 6 deletions

diff --git a/drivers/hwmon/adt7475.c b/drivers/hwmon/adt7475.c
index 688b0a1af5a8..eac24c1361bc 100644
--- a/drivers/hwmon/adt7475.c
+++ b/drivers/hwmon/adt7475.c
@@ -80,6 +80,8 @@
 
 #define REG_TEMP_OFFSET_BASE    0x70
 
+#define REG_CONFIG2             0x73
+
 #define REG_EXTEND1             0x76
 #define REG_EXTEND2             0x77
 
@@ -92,11 +94,15 @@
 #define REG_VTT_MIN             0x84    /* ADT7490 only */
 #define REG_VTT_MAX             0x86    /* ADT7490 only */
 
+#define CONFIG2_ATTN            0x20
+
 #define CONFIG3_SMBALERT        0x01
 #define CONFIG3_THERM           0x02
 
 #define CONFIG4_PINFUNC         0x03
 #define CONFIG4_MAXDUTY         0x08
+#define CONFIG4_ATTN_IN10       0x30
+#define CONFIG4_ATTN_IN43       0xC0
 
 #define CONFIG5_TWOSCOMP        0x01
 #define CONFIG5_TEMPOFFSET      0x02
@@ -157,6 +163,7 @@ struct adt7475_data {
         u8 config4;
         u8 config5;
         u8 has_voltage;
+        u8 bypass_attn;         /* Bypass voltage attenuator */
         u8 has_pwm2:1;
         u8 has_fan4:1;
         u32 alarms;
@@ -233,19 +240,24 @@ static const int adt7473_in_scaling[ADT7475_VOLTAGE_COUNT + 1][2] = {
         { 45, 45 },     /* Vtt */
 };
 
-static inline int reg2volt(int channel, u16 reg)
+static inline int reg2volt(int channel, u16 reg, u8 bypass_attn)
 {
         const int *r = adt7473_in_scaling[channel];
 
+        if (bypass_attn & (1 << channel))
+                return DIV_ROUND_CLOSEST(reg * 2250, 1024);
         return DIV_ROUND_CLOSEST(reg * (r[0] + r[1]) * 2250, r[1] * 1024);
 }
 
-static inline u16 volt2reg(int channel, long volt)
+static inline u16 volt2reg(int channel, long volt, u8 bypass_attn)
 {
         const int *r = adt7473_in_scaling[channel];
         long reg;
 
-        reg = (volt * r[1] * 1024) / ((r[0] + r[1]) * 2250);
+        if (bypass_attn & (1 << channel))
+                reg = (volt * 1024) / 2250;
+        else
+                reg = (volt * r[1] * 1024) / ((r[0] + r[1]) * 2250);
         return SENSORS_LIMIT(reg, 0, 1023) & (0xff << 2);
 }
 
@@ -305,7 +317,8 @@ static ssize_t show_voltage(struct device *dev, struct device_attribute *attr,
                                (data->alarms >> sattr->index) & 1);
         default:
                 val = data->voltage[sattr->nr][sattr->index];
-                return sprintf(buf, "%d\n", reg2volt(sattr->index, val));
+                return sprintf(buf, "%d\n",
+                               reg2volt(sattr->index, val, data->bypass_attn));
         }
 }
 
@@ -324,7 +337,8 @@ static ssize_t set_voltage(struct device *dev, struct device_attribute *attr,
 
         mutex_lock(&data->lock);
 
-        data->voltage[sattr->nr][sattr->index] = volt2reg(sattr->index, val);
+        data->voltage[sattr->nr][sattr->index] =
+                                volt2reg(sattr->index, val, data->bypass_attn);
 
         if (sattr->index < ADT7475_VOLTAGE_COUNT) {
                 if (sattr->nr == MIN)
@@ -1159,7 +1173,7 @@ static int adt7475_probe(struct i2c_client *client,
 
         struct adt7475_data *data;
         int i, ret = 0, revision;
-        u8 config3;
+        u8 config2, config3;
 
         data = kzalloc(sizeof(*data), GFP_KERNEL);
         if (data == NULL)
@@ -1205,6 +1219,16 @@ static int adt7475_probe(struct i2c_client *client,
                         data->has_voltage |= (1 << 0);          /* in0 */
         }
 
+        /* Voltage attenuators can be bypassed, globally or individually */
+        config2 = adt7475_read(REG_CONFIG2);
+        if (config2 & CONFIG2_ATTN) {
+                data->bypass_attn = (0x3 << 3) | 0x3;
+        } else {
+                data->bypass_attn = ((data->config4 & CONFIG4_ATTN_IN10) >> 4) |
+                                    ((data->config4 & CONFIG4_ATTN_IN43) >> 3);
+        }
+        data->bypass_attn &= data->has_voltage;
+
         /* Call adt7475_read_pwm for all pwm's as this will reprogram any
            pwm's which are disabled to manual mode with 0% duty cycle */
         for (i = 0; i < ADT7475_PWM_COUNT; i++)
@@ -1251,6 +1275,12 @@ static int adt7475_probe(struct i2c_client *client,
                          (data->has_voltage & (1 << 0)) ? " in0" : "",
                          data->has_fan4 ? " fan4" : "",
                          data->has_pwm2 ? " pwm2" : "");
+        if (data->bypass_attn)
+                dev_info(&client->dev, "Bypassing attenuators on:%s%s%s%s\n",
+                         (data->bypass_attn & (1 << 0)) ? " in0" : "",
+                         (data->bypass_attn & (1 << 1)) ? " in1" : "",
+                         (data->bypass_attn & (1 << 3)) ? " in3" : "",
+                         (data->bypass_attn & (1 << 4)) ? " in4" : "");
 
         return 0;