[PATCH 5.4 18/47] hwmon: (lm90) Add max6654 support to lm90 driver

Greg Kroah-Hartman
2021-12-27T15:36:54Z

From: Josh Lehan <krellan@google.com>

[ Upstream commit 229d495d8189ae785dacee72e5633a58edc25ddf ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
Documentation/hwmon/lm90.rst | 23 ++++++++++++++++--
drivers/hwmon/Kconfig | 9 ++++----
drivers/hwmon/lm90.c | 45 ++++++++++++++++++++++++++++++++----
3 files changed, 67 insertions(+), 10 deletions(-)

diff --git a/Documentation/hwmon/lm90.rst b/Documentation/hwmon/lm90.rst
index 953315987c06e..78dfc01b47a23 100644
--- a/Documentation/hwmon/lm90.rst
+++ b/Documentation/hwmon/lm90.rst
@@ -123,6 +123,18 @@ Supported chips:

http://www.maxim-ic.com/quick_view2.cfm/qv_pk/3497

+ * Maxim MAX6654
+
+ Prefix: 'max6654'
+
+ Addresses scanned: I2C 0x18, 0x19, 0x1a, 0x29, 0x2a, 0x2b,
+
+ 0x4c, 0x4d and 0x4e
+
+ Datasheet: Publicly available at the Maxim website
+
+ https://www.maximintegrated.com/en/products/sensors/MAX6654.html
+
* Maxim MAX6657

Prefix: 'max6657'
@@ -301,6 +313,13 @@ ADT7461, ADT7461A, NCT1008:
* Extended temperature range (breaks compatibility)
* Lower resolution for remote temperature

+MAX6654:
+ * Better local resolution
+ * Selectable address
+ * Remote sensor type selection
+ * Extended temperature range
+ * Extended resolution only available when conversion rate <= 1 Hz
+
MAX6657 and MAX6658:
* Better local resolution
* Remote sensor type selection
@@ -336,8 +355,8 @@ SA56004X:

All temperature values are given in degrees Celsius. Resolution
is 1.0 degree for the local temperature, 0.125 degree for the remote
-temperature, except for the MAX6657, MAX6658 and MAX6659 which have a
-resolution of 0.125 degree for both temperatures.
+temperature, except for the MAX6654, MAX6657, MAX6658 and MAX6659 which have
+a resolution of 0.125 degree for both temperatures.

Each sensor has its own high and low limits, plus a critical limit.
Additionally, there is a relative hysteresis value common to both critical
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 13a6b4afb4b36..fdf8fab7eb396 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -1132,10 +1132,11 @@ config SENSORS_LM90
help
If you say yes here you get support for National Semiconductor LM90,
LM86, LM89 and LM99, Analog Devices ADM1032, ADT7461, and ADT7461A,
- Maxim MAX6646, MAX6647, MAX6648, MAX6649, MAX6657, MAX6658, MAX6659,
- MAX6680, MAX6681, MAX6692, MAX6695, MAX6696, ON Semiconductor NCT1008,
- Winbond/Nuvoton W83L771W/G/AWG/ASG, Philips SA56004, GMT G781, and
- Texas Instruments TMP451 sensor chips.
+ Maxim MAX6646, MAX6647, MAX6648, MAX6649, MAX6654, MAX6657, MAX6658,
+ MAX6659, MAX6680, MAX6681, MAX6692, MAX6695, MAX6696,
+ ON Semiconductor NCT1008, Winbond/Nuvoton W83L771W/G/AWG/ASG,
+ Philips SA56004, GMT G781, and Texas Instruments TMP451
+ sensor chips.

This driver can also be built as a module. If so, the module
will be called lm90.
diff --git a/drivers/hwmon/lm90.c b/drivers/hwmon/lm90.c
index 6d6f543baea68..9d48a7405932f 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 },
@@ -269,6 +278,10 @@ static const struct of_device_id __maybe_unused lm90_of_match[] = {
.compatible = "dallas,max6649",
.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,
@@ -1556,6 +1574,16 @@ 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
@@ -1659,6 +1687,15 @@ static int lm90_init_client(struct i2c_client *client, struct lm90_data *data)
if (data->kind == max6680)
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
*/
--
2.34.1