The TMP125 is a 2 degree Celsius accurate Digital Temperature Sensor with a SPI interface. The temperature register is a 16-bit, read-only register. The MSB (Bit 15) is a leading zero and never set. Bits 14 to 5 are the 1+9 temperature data bits in a signed two's complement format. Bits 4 to 0 are mirrors of Bit 5 and therefore ignored. This was tested on a Aerohive HiveAP-350. Bonus: lm70 supports TMP122/TMP124 as well. So, I added them to the Kconfig module description as well. Signed-off-by: Christian Lamparter <chunkeey@xxxxxxxxx> --- Datasheet: (Link) <https://www.ti.com/lit/ds/symlink/tmp125.pdf> I'm not sure if it's "Ok" to add the TMP125 to this lm70. It seems like it, especially since the TMP124 and friends are supported by this driver. --- drivers/hwmon/Kconfig | 4 ++-- drivers/hwmon/lm70.c | 15 +++++++++++++++ 2 files changed, 17 insertions(+), 2 deletions(-) diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig index 8df25f1079ba..5cdf38004fae 100644 --- a/drivers/hwmon/Kconfig +++ b/drivers/hwmon/Kconfig @@ -1208,8 +1208,8 @@ config SENSORS_LM70 depends on SPI_MASTER help If you say yes here you get support for the National Semiconductor - LM70, LM71, LM74 and Texas Instruments TMP121/TMP123 digital tempera- - ture sensor chips. + LM70, LM71, LM74 and Texas Instruments TMP121/TMP123, TMP122/TMP124 + and TMP125 digital temperature sensor chips. This driver can also be built as a module. If so, the module will be called lm70. diff --git a/drivers/hwmon/lm70.c b/drivers/hwmon/lm70.c index d2a60de5b8de..4202e4e03584 100644 --- a/drivers/hwmon/lm70.c +++ b/drivers/hwmon/lm70.c @@ -34,6 +34,7 @@ #define LM70_CHIP_LM71 2 /* NS LM71 */ #define LM70_CHIP_LM74 3 /* NS LM74 */ #define LM70_CHIP_TMP122 4 /* TI TMP122/TMP124 */ +#define LM70_CHIP_TMP125 5 /* TI TMP125 */ struct lm70 { struct spi_device *spi; @@ -87,6 +88,11 @@ static ssize_t temp1_input_show(struct device *dev, * LM71: * 14 bits of 2's complement data, discard LSB 2 bits, * resolution 0.0312 degrees celsius. + * + * TMP125: + * MSB/D15 is a leading zero. D14 is the sign-bit followed by + * 9 temperature bits (D13..D5) of 2's complement data, + * discard LSB 5 bits (same as D5), resolution 0.25 degress celsius. */ switch (p_lm70->chip) { case LM70_CHIP_LM70: @@ -102,6 +108,10 @@ static ssize_t temp1_input_show(struct device *dev, case LM70_CHIP_LM71: val = ((int)raw / 4) * 3125 / 100; break; + + case LM70_CHIP_TMP125: + val = sign_extend32(raw, 14) / 32 * 250; + break; } status = sprintf(buf, "%d\n", val); /* millidegrees Celsius */ @@ -135,6 +145,10 @@ static const struct of_device_id lm70_of_ids[] = { .compatible = "ti,tmp122", .data = (void *) LM70_CHIP_TMP122, }, + { + .compatible = "ti,tmp125", + .data = (void *) LM70_CHIP_TMP125, + }, { .compatible = "ti,lm71", .data = (void *) LM70_CHIP_LM71, @@ -184,6 +198,7 @@ static const struct spi_device_id lm70_ids[] = { { "lm70", LM70_CHIP_LM70 }, { "tmp121", LM70_CHIP_TMP121 }, { "tmp122", LM70_CHIP_TMP122 }, + { "tmp125", LM70_CHIP_TMP125 }, { "lm71", LM70_CHIP_LM71 }, { "lm74", LM70_CHIP_LM74 }, { }, -- 2.35.1
