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>

diff --git a/target/linux/generic/backport-5.10/870-hwmon-next-hwmon-lm70-Add-ti-tmp125-support.patch b/target/linux/generic/backport-5.10/870-hwmon-next-hwmon-lm70-Add-ti-tmp125-support.patch
new file mode 100644 (file)
index 0000000..fabf177
--- /dev/null
+++ b/target/linux/generic/backport-5.10/870-hwmon-next-hwmon-lm70-Add-ti-tmp125-support.patch
@@ -0,0 +1,71 @@
+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 },
+       { },

diff --git a/target/linux/mpc85xx/files/arch/powerpc/boot/dts/hiveap-330.dts b/target/linux/mpc85xx/files/arch/powerpc/boot/dts/hiveap-330.dts
index bb2f2d0827838e7202ea779c8ad1228bfd571b8d..ccf60eaeed0e103456567840c7c135dec0d7b6a4 100644 (file)
--- a/target/linux/mpc85xx/files/arch/powerpc/boot/dts/hiveap-330.dts
+++ b/target/linux/mpc85xx/files/arch/powerpc/boot/dts/hiveap-330.dts
@@ -24,6 +24,7 @@
                led-running = &led_power_green;
                led-upgrade = &led_fault_red;
                label-mac-device = &enet0;
+               spi0 = &spi0;
        };
 
        memory {
@@ -113,6 +114,14 @@
        board_soc: soc: soc@ffe00000 {
                ranges = <0x0 0x0 0xffe00000 0x100000>;
 
+               spi0: spi@7000 {
+                       temperature-sensor@1 {
+                               compatible = "ti,tmp125";
+                               reg = <1>;
+                               spi-max-frequency = <5000000>;
+                       };
+               };
+
                i2c@3100 {
                        tpm@29 {
                                compatible = "atmel,at97sc3204t";

diff --git a/target/linux/mpc85xx/image/p1020.mk b/target/linux/mpc85xx/image/p1020.mk
index a50b489df1bae8d39f443e0d0c12c2b4df540562..64cad1ad9c200d5c04130817205719dc81c6d322 100644 (file)
--- a/target/linux/mpc85xx/image/p1020.mk
+++ b/target/linux/mpc85xx/image/p1020.mk
@@ -15,7 +15,7 @@ define Device/aerohive_hiveap-330
   DEVICE_MODEL := HiveAP-330
   DEVICE_ALT0_VENDOR := Aerohive
   DEVICE_ALT0_MODEL := HiveAP-350
-  DEVICE_PACKAGES := kmod-tpm-i2c-atmel
+  DEVICE_PACKAGES := kmod-tpm-i2c-atmel kmod-hwmon-lm70
   BLOCKSIZE := 128k
   KERNEL := kernel-bin | uImage none
   KERNEL_INITRAMFS := kernel-bin | MultiImage none