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authorKun Yi2018-09-11 13:25:58 -0700
committerGuenter Roeck2018-10-10 20:37:13 -0700
commita54ca77a98a311bf0488fd9004c5b691454ff917 (patch)
tree0bb1f863c2a770bdbada476609d501f63f5c9925
parent39ea6ea325dcd05daf65f3d9d8d205a55683668f (diff)
hwmon: (lm75) Add MAX31725/6 support
MAX31725/MAX31726 are local temperature sensors with +/- 0.5 degree Celsius accuracy and 16-bit (0.00390625 degrees Celsius) resolution. They have a register mapping and encoding compatible with the lm75 series drivers. Address scan and extended temperature range are not supported by this patch. Tested on real hardware and verified temperature readings are correct. Signed-off-by: Kun Yi <kunyi@google.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
-rw-r--r--Documentation/hwmon/lm756
-rw-r--r--drivers/hwmon/lm75.c18
2 files changed, 19 insertions, 5 deletions
diff --git a/Documentation/hwmon/lm75 b/Documentation/hwmon/lm75
index ac95edfcd907..2f1120f88c16 100644
--- a/Documentation/hwmon/lm75
+++ b/Documentation/hwmon/lm75
@@ -17,8 +17,8 @@ Supported chips:
Addresses scanned: none
Datasheet: Publicly available at the Maxim website
http://www.maximintegrated.com/
- * Maxim MAX6625, MAX6626
- Prefixes: 'max6625', 'max6626'
+ * Maxim MAX6625, MAX6626, MAX31725, MAX31726
+ Prefixes: 'max6625', 'max6626', 'max31725', 'max31726'
Addresses scanned: none
Datasheet: Publicly available at the Maxim website
http://www.maxim-ic.com/
@@ -86,7 +86,7 @@ The LM75 is essentially an industry standard; there may be other
LM75 clones not listed here, with or without various enhancements,
that are supported. The clones are not detected by the driver, unless
they reproduce the exact register tricks of the original LM75, and must
-therefore be instantiated explicitly. Higher resolution up to 12-bit
+therefore be instantiated explicitly. Higher resolution up to 16-bit
is supported by this driver, other specific enhancements are not.
The LM77 is not supported, contrary to what we pretended for a long time.
diff --git a/drivers/hwmon/lm75.c b/drivers/hwmon/lm75.c
index 49f4b33a5685..e6e5a1080f09 100644
--- a/drivers/hwmon/lm75.c
+++ b/drivers/hwmon/lm75.c
@@ -47,6 +47,7 @@ enum lm75_type { /* keep sorted in alphabetical order */
lm75b,
max6625,
max6626,
+ max31725,
mcp980x,
stds75,
tcn75,
@@ -64,7 +65,6 @@ enum lm75_type { /* keep sorted in alphabetical order */
static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c,
0x4d, 0x4e, 0x4f, I2C_CLIENT_END };
-
/* The LM75 registers */
#define LM75_REG_TEMP 0x00
#define LM75_REG_CONF 0x01
@@ -76,7 +76,7 @@ struct lm75_data {
struct i2c_client *client;
struct regmap *regmap;
u8 orig_conf;
- u8 resolution; /* In bits, between 9 and 12 */
+ u8 resolution; /* In bits, between 9 and 16 */
u8 resolution_limits;
unsigned int sample_time; /* In ms */
};
@@ -339,6 +339,10 @@ lm75_probe(struct i2c_client *client, const struct i2c_device_id *id)
data->resolution_limits = 9;
data->sample_time = MSEC_PER_SEC / 4;
break;
+ case max31725:
+ data->resolution = 16;
+ data->sample_time = MSEC_PER_SEC / 8;
+ break;
case tcn75:
data->resolution = 9;
data->sample_time = MSEC_PER_SEC / 8;
@@ -415,6 +419,8 @@ static const struct i2c_device_id lm75_ids[] = {
{ "lm75b", lm75b, },
{ "max6625", max6625, },
{ "max6626", max6626, },
+ { "max31725", max31725, },
+ { "max31726", max31725, },
{ "mcp980x", mcp980x, },
{ "stds75", stds75, },
{ "tcn75", tcn75, },
@@ -472,6 +478,14 @@ static const struct of_device_id lm75_of_match[] = {
.data = (void *)max6626
},
{
+ .compatible = "maxim,max31725",
+ .data = (void *)max31725
+ },
+ {
+ .compatible = "maxim,max31726",
+ .data = (void *)max31725
+ },
+ {
.compatible = "maxim,mcp980x",
.data = (void *)mcp980x
},