drivers: comparator: stm32: Add support for STM32(G4) comparator

Add the Devicetree binding

Move the data struct to source file, remove extraneous comments

Add all config options into DT binding

Make comment more generic

drivers: comparator: stm32: Add support for STM32(G4) comparator

Add support for built-in comparator on the STM32G4x series

Signed-off-by: Adam Mitchell <[email protected]>

Addressing linter comments

Address more lint issues

Update license to Apache-2.0

Blank lines after declarations

drivers/CMakeLists.txt

@@ -20,6 +20,7 @@ add_subdirectory_ifdef(CONFIG_BT_DRIVERS bluetooth)
 add_subdirectory_ifdef(CONFIG_CACHE_MANAGEMENT cache)
 add_subdirectory_ifdef(CONFIG_CAN can)
 add_subdirectory_ifdef(CONFIG_CLOCK_CONTROL clock_control)
+add_subdirectory_ifdef(CONFIG_COMPARATOR comparator)
 add_subdirectory_ifdef(CONFIG_CHARGER charger)
 add_subdirectory_ifdef(CONFIG_CONSOLE console)
 add_subdirectory_ifdef(CONFIG_COREDUMP_DEVICE coredump)

drivers/Kconfig

@@ -13,6 +13,7 @@ source "drivers/bluetooth/Kconfig"
 source "drivers/cache/Kconfig"
 source "drivers/can/Kconfig"
 source "drivers/charger/Kconfig"
+source "drivers/comparator/Kconfig"
 source "drivers/clock_control/Kconfig"
 source "drivers/console/Kconfig"
 source "drivers/coredump/Kconfig"

drivers/comparator/CMakeLists.txt

@@ -0,0 +1,7 @@
+# SPDX-License-Identifier: Apache-2.0
+
+zephyr_syscall_header(${ZEPHYR_BASE}/include/zephyr/drivers/comparator.h)
+
+zephyr_library()
+
+zephyr_library_sources_ifdef(CONFIG_COMP_STM32 comp_stm32.c)

drivers/comparator/Kconfig

@@ -0,0 +1,44 @@
+# Comparator configuration options
+
+# Copyright (c) 2023 Adam Mitchell, Brill Power Ltd
+# SPDX-License-Identifier: Apache-2.0
+
+#
+# Comparator options
+#
+menuconfig COMPARATOR
+	bool "Comparator drivers"
+	help
+	  Enable comparator driver configuration
+
+if COMPARATOR
+
+module = COMPARATOR
+module-str = comparator
+source "subsys/logging/Kconfig.template.log_config"
+
+config COMP_INIT_PRIORITY
+	int "Comparator init priority"
+	default KERNEL_INIT_PRIORITY_DEVICE
+	depends on COMPARATOR
+	help
+	  Comparator driver device initialization priority.
+
+config COMP_ENABLE_AT_INIT
+	bool "Automatically enable comparator during initialisation function"
+	default y
+	depends on COMPARATOR
+	help
+	  Enable comparators at the end of the initialisation
+	  function rather than via explicit call in application code
+
+config COMP_LOCK
+	bool "Lock comparator during initialisation function"
+	default n
+	depends on COMPARATOR
+	help
+	  Prevent modification of comparator configuration after initialisation
+
+source "drivers/dac/Kconfig.stm32"
+
+endif # COMPARATOR

drivers/comparator/Kconfig.stm32

@@ -0,0 +1,12 @@
+# Comparator configuration options
+
+# Copyright (c) 2023 Adam Mitchell, Brill Power Ltd
+# SPDX-License-Identifier: Apache-2.0
+
+config COMP_STM32
+	bool "STM32 Comparator driver"
+	default n
+	depends on DT_HAS_ST_STM32_COMP_ENABLED
+	select USE_STM32_LL_COMP
+	help
+	  Enable the driver implementation for STM32 microcontrollers

drivers/comparator/comp_stm32.c

@@ -0,0 +1,144 @@
+/*
+ * Copyright (c) 2023 Adam Mitchell, Brill Power Ltd
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#define DT_DRV_COMPAT st_stm32_comp
+
+#include <errno.h>
+#include <soc.h>
+
+#include <zephyr/device.h>
+#include <zephyr/drivers/clock_control/stm32_clock_control.h>
+#include <zephyr/drivers/comparator.h>
+#include <zephyr/drivers/pinctrl.h>
+#include <zephyr/init.h>
+
+#include <stm32_ll_bus.h>
+#include <stm32_ll_comp.h>
+
+#define LOG_LEVEL CONFIG_COMPARATOR_LOG_LEVEL
+#include <zephyr/logging/log.h>
+LOG_MODULE_REGISTER(comp_stm32);
+
+struct comp_cfg {
+	COMP_TypeDef *base;
+	struct stm32_pclken pclken;
+	const struct pinctrl_dev_config *pcfg;
+};
+
+struct comp_data
+	uint32_t input_plus;
+	uint32_t input_minus;
+	uint32_t input_hysteresis;
+	uint32_t output_polarity;
+	uint32_t output_blanking_source;
+};
+
+static void comp_stm32_enable(const struct device *dev)
+{
+	const struct comp_cfg *cfg = dev->config;
+
+	LL_COMP_Enable(cfg->base);
+}
+
+static void comp_stm32_disable(const struct device *dev)
+{
+	const struct comp_cfg *cfg = dev->config;
+
+	LL_COMP_Disable(cfg->base);
+}
+
+#ifdef CONFIG_COMP_LOCK
+static void comp_stm32_lock(const struct device *dev)
+{
+	const struct comp_cfg *cfg = dev->config;
+
+	LL_COMP_Lock(cfg->base);
+}
+#endif /* CONFIG_COMP_LOCK */
+
+static int comp_stm32_init(const struct device *dev)
+{
+	const struct comp_cfg *cfg = dev->config;
+	const struct comp_data *data = dev->data;
+	const struct device *const clk = DEVICE_DT_GET(STM32_CLOCK_CONTROL_NODE);
+
+	if (!device_is_ready(clk)) {
+		LOG_ERR("clock control device not ready");
+		return -ENODEV;
+	}
+
+	if (clock_control_on(clk, (clock_control_subsys_t *)&cfg->pclken) != 0) {
+		return -EIO;
+	}
+
+	int err = pinctrl_apply_state(cfg->pcfg, PINCTRL_STATE_DEFAULT);
+
+	if (err < 0) {
+		LOG_ERR("%s pinctrl setup failed (%d)", cfg->base, err);
+		return err;
+	}
+
+	LL_COMP_InitTypeDef Comp_InitStruct = { 0 };
+
+	Comp_InitStruct.InputPlus = data->input_plus;
+	Comp_InitStruct.InputMinus = data->input_minus;
+	Comp_InitStruct.InputHysteresis = data->input_hysteresis;
+	Comp_InitStruct.OutputPolarity = data->output_polarity;
+	Comp_InitStruct.OutputBlankingSource = data->output_blanking_source;
+
+	err = LL_COMP_Init(cfg->base, &Comp_InitStruct);
+	if (err != SUCCESS) {
+		LOG_ERR("%s initialisation failed!", cfg->base);
+		return -ENODEV;
+	}
+
+#ifdef CONFIG_COMP_ENABLE_AT_INIT
+	LL_COMP_Enable(cfg->base);
+#endif /* CONFIG_COMP_ENABLE_AT_INIT */
+
+#ifdef CONFIG_COMP_LOCK
+	LL_COMP_Lock(cfg->base);
+#endif /* CONFIG_COMP_LOCK */
+
+	return 0;
+}
+
+static const struct comp_driver_api comp_stm32_driver_api = {
+	.enable = comp_stm32_enable,
+	.disable = comp_stm32_disable,
+#ifdef CONFIG_COMP_LOCK
+	.lock = comp_stm32_lock,
+#endif /* CONFIG_COMP_LOCK */
+};
+
+
+#define STM32_COMP_INIT(index) \
+\
+	PINCTRL_DT_INST_DEFINE(index); \
+\
+	static const struct comp_cfg comp_stm32_cfg_##index = { \
+		.base = (COMP_TypeDef *)DT_INST_REG_ADDR(index), \
+		.pclken = { \
+			.enr = DT_INST_CLOCKS_CELL(index, bits), \
+			.bus = DT_INST_CLOCKS_CELL(index, bus), \
+		},                     \
+		.pcfg = PINCTRL_DT_INST_DEV_CONFIG_GET(index), \
+	}; \
+\
+	static struct comp_data comp_stm32_data_##index = { \
+		.input_plus = DT_INST_PROP_OR(index, input_plus, LL_COMP_INPUT_PLUS_IO1), \
+		.input_minus = DT_INST_PROP_OR(index, input_minus, LL_COMP_INPUT_MINUS_IO1), \
+		.input_hysteresis = DT_INST_PROP_OR(index, input_hysteresis, LL_COMP_HYSTERESIS_NONE), \
+		.output_polarity = DT_INST_PROP_OR(index, output_polarity, LL_COMP_OUTPUTPOL_NONINVERTED), \
+		.output_blanking_source = \
+			DT_INST_PROP_OR(index, output_blanking_source, LL_COMP_BLANKINGSRC_NONE) \
+	}; \
+\
+	DEVICE_DT_INST_DEFINE(index, &comp_stm32_init, NULL, &comp_stm32_data_##index, \
+						  &comp_stm32_cfg_##index, POST_KERNEL, CONFIG_COMP_INIT_PRIORITY, \
+						  &comp_stm32_driver_api);
+
+DT_INST_FOREACH_STATUS_OKAY(STM32_COMP_INIT)

dts/bindings/comparator/st,stm32-comp.yaml

@@ -0,0 +1,107 @@
+# Copyright (c) 2023 Adam Mitchell, Brill Power Ltd
+# SPDX-License-Identifier: Apache-2.0
+
+description: ST STM32 family comparator
+
+compatible: "st,stm32-comp"
+
+include: [base.yaml, pinctrl-device.yaml]
+
+properties:
+  reg:
+    required: true
+
+  pinctrl-0:
+    required: true
+
+  pinctrl-names:
+    required: true
+
+  input-plus:
+    required: true
+    type: int
+    enum:
+      - 0   # LL_COMP_INPUT_PLUS_IO1
+      - 256 # LL_COMP_INPUT_PLUS_IO2
+    description: |
+      Specify non-inverting input source
+
+  input-minus:
+    required: true
+    type: int
+    enum:
+      # LL_COMP_INPUT_MINUS_DAC3_CH1 / LL_COMP_INPUT_MINUS_DAC3_CH2
+      # LL_COMP_INPUT_MINUS_DAC4_CH1 / LL_COMP_INPUT_MINUS_DAC4_CH2
+      - 64
+
+      # LL_COMP_INPUT_MINUS_DAC1_CH1 / LL_COMP_INPUT_MINUS_DAC1_CH2
+      # LL_COMP_INPUT_MINUS_DAC2_CH1
+      - 80
+
+      - 96 # LL_COMP_INPUT_MINUS_IO1
+      - 112 # LL_COMP_INPUT_MINUS_IO2
+      - 8388656  # LL_COMP_INPUT_MINUS_VREFINT
+      - 12582912 # LL_COMP_INPUT_MINUS_1_4VREFINT
+      - 12582928 # LL_COMP_INPUT_MINUS_1_2VREFINT
+      - 12582944 # LL_COMP_INPUT_MINUS_3_4VREFINT
+    description: |
+      Specify inverting input source
+
+  input-hysteresis:
+    required: true
+    type: int
+    enum:
+      - 0 # LL_COMP_HYSTERESIS_NONE
+      - 65536 # LL_COMP_HYSTERESIS_10MV / LL_COMP_HYSTERESIS_LOW
+      - 131072 # LL_COMP_HYSTERESIS_20MV
+      - 196608 # LL_COMP_HYSTERESIS_30MV
+      - 262144 # LL_COMP_HYSTERESIS_40MV / LL_COMP_HYSTERESIS_MEDIUM
+      - 327680 # LL_COMP_HYSTERESIS_50MV
+      - 393216 # LL_COMP_HYSTERESIS_60MV
+      - 458752 # LL_COMP_HYSTERESIS_70MV / LL_COMP_HYSTERESIS_HIGH
+    description: |
+      Specify hysteresis mode for inverting input
+
+  output-polarity:
+    required: true
+    type: int
+    enum:
+      - 0     # LL_COMP_OUTPUTPOL_NONINVERTED
+      - 32768 # LL_COMP_OUTPUTPOL_INVERTED
+    description: |
+      Specify output polarity
+
+  output-blanking-source:
+    required: true
+    type: int
+    enum:
+      - 0 # LL_COMP_BLANKINGSRC_NONE
+
+      # LL_COMP_BLANKINGSRC_TIM1_OC5_COMP1 / LL_COMP_BLANKINGSRC_TIM1_OC5_COMP2
+      # LL_COMP_BLANKINGSRC_TIM1_OC5_COMP3 / LL_COMP_BLANKINGSRC_TIM1_OC5_COMP7
+      # LL_COMP_BLANKINGSRC_TIM2_OC3_COMP5 / LL_COMP_BLANKINGSRC_TIM3_OC4_COMP4
+      # LL_COMP_BLANKINGSRC_TIM8_OC5_COMP6
+      - 524288
+
+      # LL_COMP_BLANKINGSRC_TIM2_OC3_COMP1 / LL_COMP_BLANKINGSRC_TIM2_OC3_COMP2
+      # LL_COMP_BLANKINGSRC_TIM2_OC4_COMP6 / LL_COMP_BLANKINGSRC_TIM3_OC3_COMP3
+      # LL_COMP_BLANKINGSRC_TIM8_OC5_COMP4 / LL_COMP_BLANKINGSRC_TIM8_OC5_COMP5
+      # LL_COMP_BLANKINGSRC_TIM8_OC5_COMP7
+      - 1048576
+      # LL_COMP_BLANKINGSRC_TIM2_OC4_COMP3 / LL_COMP_BLANKINGSRC_TIM3_OC3_COMP1
+      # LL_COMP_BLANKINGSRC_TIM3_OC3_COMP2 / LL_COMP_BLANKINGSRC_TIM3_OC3_COMP5
+      # LL_COMP_BLANKINGSRC_TIM3_OC3_COMP7 / LL_COMP_BLANKINGSRC_TIM15_OC1_COMP4
+      # LL_COMP_BLANKINGSRC_TIM15_OC2_COMP6
+      - 1572864
+
+      # LL_COMP_BLANKINGSRC_TIM1_OC5_COMP4 / LL_COMP_BLANKINGSRC_TIM1_OC5_COMP5
+      # LL_COMP_BLANKINGSRC_TIM1_OC5_COMP6 / LL_COMP_BLANKINGSRC_TIM8_OC5_COMP1
+      # LL_COMP_BLANKINGSRC_TIM8_OC5_COMP2 / LL_COMP_BLANKINGSRC_TIM8_OC5_COMP3
+      # LL_COMP_BLANKINGSRC_TIM15_OC2_COMP7
+      - 2097152
+
+      - 2621440 # LL_COMP_BLANKINGSRC_TIM20_OC5
+      - 3145728 # LL_COMP_BLANKINGSRC_TIM15_OC1
+      - 3670016 # LL_COMP_BLANKINGSRC_TIM4_OC3
+    description: |
+      Specify output blanking source