hwmon: (adt7475) Voltage attenuators can be bypassed
It is possible to bypass the voltage attenuators on the +2.5V, Vccp,
+5V and +12V voltage monitoring inputs. This is useful to connect
other voltage channels than the ones the monitoring chip was
originally designed for. When this feature is enabled, we must not
include the scaling factors in our computations.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Jordan Crouse <jordan@cosmicpenguin.net>
Cc: "Darrick J. Wong" <djwong@us.ibm.com>
diff --git a/drivers/hwmon/adt7475.c b/drivers/hwmon/adt7475.c
index 688b0a1..eac24c1 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 @@
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 @@
{ 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 @@
(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 @@
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 @@
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 @@
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 @@
(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;