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authorJosh Lehan <krellan@google.com>2020-05-13 21:42:48 +0300
committerGuenter Roeck <linux@roeck-us.net>2020-05-22 16:28:38 +0300
commit229d495d8189ae785dacee72e5633a58edc25ddf (patch)
tree9f7510037ff00f4fc61b28b0316305eb7f0b8aee /drivers/hwmon/lm90.c
parent036855a4c3b3703ef44b5edb83b794d1b99d51f6 (diff)
downloadlinux-229d495d8189ae785dacee72e5633a58edc25ddf.tar.xz
hwmon: (lm90) Add max6654 support to lm90 driver
Add support for the Maxim MAX6654 to the lm90 driver. The MAX6654 is a temperature sensor, similar to the others, but with some differences regarding the configuration register, and the sampling rate at which extended resolution becomes possible. Signed-off-by: Josh Lehan <krellan@google.com> Link: https://lore.kernel.org/r/20200513184248.145765-1-krellan@google.com Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Diffstat (limited to 'drivers/hwmon/lm90.c')
-rw-r--r--drivers/hwmon/lm90.c45
1 files changed, 41 insertions, 4 deletions
diff --git a/drivers/hwmon/lm90.c b/drivers/hwmon/lm90.c
index 9b3c9f390ef8..7bdc664af55b 100644
--- a/drivers/hwmon/lm90.c
+++ b/drivers/hwmon/lm90.c
@@ -35,6 +35,14 @@
* explicitly as max6659, or if its address is not 0x4c.
* These chips lack the remote temperature offset feature.
*
+ * This driver also supports the MAX6654 chip made by Maxim. This chip can
+ * be at 9 different addresses, similar to MAX6680/MAX6681. The MAX6654 is
+ * otherwise similar to MAX6657/MAX6658/MAX6659. Extended range is available
+ * by setting the configuration register accordingly, and is done during
+ * initialization. Extended precision is only available at conversion rates
+ * of 1 Hz and slower. Note that extended precision is not enabled by
+ * default, as this driver initializes all chips to 2 Hz by design.
+ *
* This driver also supports the MAX6646, MAX6647, MAX6648, MAX6649 and
* MAX6692 chips made by Maxim. These are again similar to the LM86,
* but they use unsigned temperature values and can report temperatures
@@ -94,8 +102,8 @@
* have address 0x4d.
* MAX6647 has address 0x4e.
* MAX6659 can have address 0x4c, 0x4d or 0x4e.
- * MAX6680 and MAX6681 can have address 0x18, 0x19, 0x1a, 0x29, 0x2a, 0x2b,
- * 0x4c, 0x4d or 0x4e.
+ * MAX6654, MAX6680, and MAX6681 can have address 0x18, 0x19, 0x1a, 0x29,
+ * 0x2a, 0x2b, 0x4c, 0x4d or 0x4e.
* SA56004 can have address 0x48 through 0x4F.
*/
@@ -104,7 +112,7 @@ static const unsigned short normal_i2c[] = {
0x4d, 0x4e, 0x4f, I2C_CLIENT_END };
enum chips { lm90, adm1032, lm99, lm86, max6657, max6659, adt7461, max6680,
- max6646, w83l771, max6696, sa56004, g781, tmp451 };
+ max6646, w83l771, max6696, sa56004, g781, tmp451, max6654 };
/*
* The LM90 registers
@@ -145,7 +153,7 @@ enum chips { lm90, adm1032, lm99, lm86, max6657, max6659, adt7461, max6680,
#define LM90_REG_R_TCRIT_HYST 0x21
#define LM90_REG_W_TCRIT_HYST 0x21
-/* MAX6646/6647/6649/6657/6658/6659/6695/6696 registers */
+/* MAX6646/6647/6649/6654/6657/6658/6659/6695/6696 registers */
#define MAX6657_REG_R_LOCAL_TEMPL 0x11
#define MAX6696_REG_R_STATUS2 0x12
@@ -209,6 +217,7 @@ static const struct i2c_device_id lm90_id[] = {
{ "max6646", max6646 },
{ "max6647", max6646 },
{ "max6649", max6646 },
+ { "max6654", max6654 },
{ "max6657", max6657 },
{ "max6658", max6657 },
{ "max6659", max6659 },
@@ -270,6 +279,10 @@ static const struct of_device_id __maybe_unused lm90_of_match[] = {
.data = (void *)max6646
},
{
+ .compatible = "dallas,max6654",
+ .data = (void *)max6654
+ },
+ {
.compatible = "dallas,max6657",
.data = (void *)max6657
},
@@ -367,6 +380,11 @@ static const struct lm90_params lm90_params[] = {
.max_convrate = 6,
.reg_local_ext = MAX6657_REG_R_LOCAL_TEMPL,
},
+ [max6654] = {
+ .alert_alarms = 0x7c,
+ .max_convrate = 7,
+ .reg_local_ext = MAX6657_REG_R_LOCAL_TEMPL,
+ },
[max6657] = {
.flags = LM90_PAUSE_FOR_CONFIG,
.alert_alarms = 0x7c,
@@ -1557,6 +1575,16 @@ static int lm90_detect(struct i2c_client *client,
&& (config1 & 0x3f) == 0x00
&& convrate <= 0x07) {
name = "max6646";
+ } else
+ /*
+ * The chip_id of the MAX6654 holds the revision of the chip.
+ * The lowest 3 bits of the config1 register are unused and
+ * should return zero when read.
+ */
+ if (chip_id == 0x08
+ && (config1 & 0x07) == 0x00
+ && convrate <= 0x07) {
+ name = "max6654";
}
} else
if (address == 0x4C
@@ -1661,6 +1689,15 @@ static int lm90_init_client(struct i2c_client *client, struct lm90_data *data)
config |= 0x18;
/*
+ * Put MAX6654 into extended range (0x20, extend minimum range from
+ * 0 degrees to -64 degrees). Note that extended resolution is not
+ * possible on the MAX6654 unless conversion rate is set to 1 Hz or
+ * slower, which is intentionally not done by default.
+ */
+ if (data->kind == max6654)
+ config |= 0x20;
+
+ /*
* Select external channel 0 for max6695/96
*/
if (data->kind == max6696)