zephyr: add shim temperature sensors

Add temperature sensors shim. Use platform/ec the temperature sensors
drivers. Generate needed global variables/types: enum temp_sensor_id
and temp_sensors from dts.

Each temperature sensor type has its own compatible property to assign
a correct read function in the temp_sensor_t temp_sensors[] array.
Themrmisors has also adc property to point an ADC channel connected to
the sensor.

Enable "temps" console command and EC_CMD_TEMP_SENSOR_GET_INFO host
command.

BUG=b:174851465
BRANCH=none
TEST=build Zephyr
TEST=Run "temps" command, it should return the current temperature
measurements

Signed-off-by: Dawid Niedzwiecki <dn@semihalf.com>
Change-Id: Ie680ec0771ea3da598066eb98db80944a93daca5
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2687218
Reviewed-by: Keith Short <keithshort@chromium.org>
Reviewed-by: Simon Glass <sjg@chromium.org>

1 files changed, 68 insertions, 0 deletions

diff --git a/zephyr/Kconfig.temperature b/zephyr/Kconfig.temperature
new file mode 100644
index 0000000000..d949c60c84
--- /dev/null
+++ b/zephyr/Kconfig.temperature
@@ -0,0 +1,68 @@
+# Copyright 2021 The Chromium OS Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+menuconfig PLATFORM_EC_TEMP_SENSOR
+	bool "Temperature sensors"
+	help
+	  Support for temperature sensors. Once enabled, "temps" console
+	  command and EC_CMD_TEMP_SENSOR_GET_INFO host command are available.
+
+if PLATFORM_EC_TEMP_SENSOR
+
+config PLATFORM_EC_THERMISTOR
+	bool "Thermistor support"
+	depends on PLATFORM_EC_ADC
+	help
+	  Enables support for thermistors (resistor whose resistance is
+	  strongly dependent on temperature) as temperature-sensor type.
+
+config PLATFORM_EC_STEINHART_HART_3V0_22K6_47K_4050B
+	bool "Steinhart-hart 3V0_22K6_47K_4050B"
+	depends on PLATFORM_EC_THERMISTOR
+	help
+	  Enables support for measuring temperature using the Steinhart-Hart
+	  equation model and the thermistor configured with the following
+	  circuit configuration:
+	  -3.0V reference voltage
+	  -22.6 kilohm fixed resistor, connected to the reference voltage
+	  -47 kilohm thermistor reference resistance at 25 C
+	  -4050 B-constant (thermistor sensitivity)
+
+config PLATFORM_EC_STEINHART_HART_3V3_13K7_47K_4050B
+	bool "Steinhart-hart 3V3_13K7_47K_4050B"
+	depends on PLATFORM_EC_THERMISTOR
+	help
+	  Enables support for measuring temperature using the Steinhart-Hart
+	  equation model and the thermistor configured with the following
+	  circuit configuration:
+	  -3.3V reference voltage
+	  -13.7 kilohm fixed resistor, connected to the reference voltage
+	  -47 kilohm thermistor reference resistance at 25 C
+	  -4050 B-constant (thermistor sensitivity)
+
+config PLATFORM_EC_STEINHART_HART_3V3_30K9_47K_4050B
+	bool "Steinhart-hart 3V3_30K9_47K_4050B"
+	depends on PLATFORM_EC_THERMISTOR
+	help
+	  Enables support for measuring temperature using the Steinhart-Hart
+	  equation model and the thermistor configured with the following
+	  circuit configuration:
+	  -3.3V reference voltage
+	  -30.9 kilohm fixed resistor, connected to the reference voltage
+	  -47 kilohm thermistor reference resistance at 25 C
+	  -4050 B-constant (thermistor sensitivity)
+
+config PLATFORM_EC_STEINHART_HART_3V3_51K1_47K_4050B
+	bool "Steinhart-hart 3V3_51K1_47K_4050B"
+	depends on PLATFORM_EC_THERMISTOR
+	default y
+	help
+	  Enables support for measuring temperature using the Steinhart-Hart
+	  equation model and the thermistor configured with the following
+	  circuit configuration:
+	  -3.3V reference voltage
+	  -51.1 kilohm fixed resistor, connected to the reference voltage
+	  -47 kilohm thermistor reference resistance at 25 C
+	  -4050 B-constant (thermistor sensitivity)
+endif # PLATFORM_EC_TEMP_SENSOR