openwrt/target/linux/generic/backport-5.10/870-hwmon-next-hwmon-lm70-Add-ti-tmp125-support.patch
Christian Lamparter 8144f9c665 mpc85xx: HiveAP-330: add tmp125 temperature sensor
the Aerohive HiveAP-330 and HiveAP-350 come equipped
with an TI TMP125 temperature chip. This patch wires
up the necessary support for this sensor and exposes
it through hwmon / thermal sensor framework. Upstream
support is coming, but it has to go through hwmon-next
first.

Signed-off-by: Christian Lamparter <chunkeey@gmail.com>
2022-02-25 17:54:56 +01:00

72 lines
2.3 KiB
Diff

From 31d8f414e1596ba54a4315418e4c0086fda9e428 Mon Sep 17 00:00:00 2001
From: Christian Lamparter <chunkeey@gmail.com>
Date: Fri, 18 Feb 2022 10:06:43 +0100
Subject: hwmon: (lm70) Add ti,tmp125 support
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 two's
complement format. Bits 4 to 0 are useless copies of
Bit 5 value and therefore ignored.
Signed-off-by: Christian Lamparter <chunkeey@gmail.com>
Link: https://lore.kernel.org/r/43b19cbd4e7f51e9509e561b02b5d8d0e7079fac.1645175187.git.chunkeey@gmail.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
--- 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 +88,12 @@ static ssize_t temp1_input_show(struct d
* 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. This is
+ * followed by 9 temperature bits (D13..D5) in 2's complement
+ * data format with a resolution of 0.25 degrees celsius per unit.
+ * LSB 5 bits (D4..D0) share the same value as D5 and get discarded.
*/
switch (p_lm70->chip) {
case LM70_CHIP_LM70:
@@ -102,6 +109,10 @@ static ssize_t temp1_input_show(struct d
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 */
@@ -136,6 +147,10 @@ static const struct of_device_id lm70_of
.data = (void *) LM70_CHIP_TMP122,
},
{
+ .compatible = "ti,tmp125",
+ .data = (void *) LM70_CHIP_TMP125,
+ },
+ {
.compatible = "ti,lm71",
.data = (void *) LM70_CHIP_LM71,
},
@@ -184,6 +199,7 @@ static const struct spi_device_id lm70_i
{ "lm70", LM70_CHIP_LM70 },
{ "tmp121", LM70_CHIP_TMP121 },
{ "tmp122", LM70_CHIP_TMP122 },
+ { "tmp125", LM70_CHIP_TMP125 },
{ "lm71", LM70_CHIP_LM71 },
{ "lm74", LM70_CHIP_LM74 },
{ },