drivers: comparator: implement stm32 comparator driver

implement the driver for the stm32 comparator peripheral

Signed-off-by: Alexander Kozhinov <[email protected]>

Author: KozhinovAlexander

drivers/comparator/CMakeLists.txt

@@ -15,3 +15,4 @@ zephyr_library_sources_ifdef(CONFIG_COMPARATOR_NRF_COMP comparator_nrf_comp.c)
 zephyr_library_sources_ifdef(CONFIG_COMPARATOR_NRF_LPCOMP comparator_nrf_lpcomp.c)
 zephyr_library_sources_ifdef(CONFIG_COMPARATOR_SHELL comparator_shell.c)
 zephyr_library_sources_ifdef(CONFIG_COMPARATOR_RENESAS_RA comparator_renesas_ra.c)
+zephyr_library_sources_ifdef(CONFIG_COMPARATOR_STM32_COMP comparator_stm32_comp.c)

drivers/comparator/Kconfig

@@ -27,5 +27,6 @@ rsource "Kconfig.nrf_comp"
 rsource "Kconfig.nrf_lpcomp"
 rsource "Kconfig.shell"
 rsource "Kconfig.renesas_ra"
+rsource "Kconfig.stm32_comp"
 
 endif # COMPARATOR

drivers/comparator/Kconfig.stm32_comp

@@ -0,0 +1,19 @@
+# Copyright (c) 2025 Alexander Kozhinov <[email protected]>
+# SPDX-License-Identifier: Apache-2.0
+
+config COMPARATOR_STM32_COMP
+	bool "ST STM32 comparator driver"
+	default y
+	depends on DT_HAS_ST_STM32_COMP_ENABLED
+	select PINCTRL
+	select EXTI_STM32
+	select USE_STM32_LL_COMP
+
+if COMPARATOR_STM32_COMP
+
+config COMPARATOR_STM32_COMP_MILLER_EFFECT_HANDLING
+	bool
+	default n
+	default y if SOC_SERIES_STM32G4X
+
+endif # COMPARATOR_STM32_COMP

drivers/comparator/comparator_stm32_comp.c

@@ -0,0 +1,318 @@
+/*
+ * Copyright (c) 2025 Alexander Kozhinov <[email protected]>
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <zephyr/irq.h>
+#include <zephyr/kernel.h>
+#include <zephyr/pm/device.h>
+#include <zephyr/sys/util_macro.h>
+#include <zephyr/drivers/pinctrl.h>
+#include <zephyr/drivers/comparator.h>
+#include <zephyr/drivers/clock_control.h>
+#include <zephyr/drivers/clock_control/stm32_clock_control.h>
+#include <zephyr/drivers/interrupt_controller/intc_exti_stm32.h>
+
+#include <stm32_ll_comp.h>
+#include <stm32_ll_system.h>
+
+#include <zephyr/logging/log.h>
+LOG_MODULE_REGISTER(stm32_comp, CONFIG_COMPARATOR_LOG_LEVEL);
+
+#define DT_DRV_COMPAT st_stm32_comp
+
+#define LL_COMP_INPUT_PLUS_IN0		LL_COMP_INPUT_PLUS_IO1
+#define LL_COMP_INPUT_PLUS_IN1		LL_COMP_INPUT_PLUS_IO2
+
+#define LL_COMP_INPUT_MINUS_IN0		LL_COMP_INPUT_MINUS_IO1
+#define LL_COMP_INPUT_MINUS_IN1		LL_COMP_INPUT_MINUS_IO2
+
+#define STM32_COMP_DT_INST_P_IN(inst)	\
+	CONCAT(LL_COMP_INPUT_PLUS_, DT_INST_STRING_TOKEN(inst, positive_input))
+
+#define STM32_COMP_DT_INST_N_IN(inst)	\
+	CONCAT(LL_COMP_INPUT_MINUS_, DT_INST_STRING_TOKEN(inst, negative_input))
+
+#define STM32_COMP_DT_INST_HYST_MODE(inst)	\
+	CONCAT(LL_COMP_HYSTERESIS_, DT_INST_STRING_TOKEN(inst, hysteresis))
+
+#define STM32_COMP_DT_INST_INV_OUT(inst)	\
+	CONCAT(LL_COMP_OUTPUTPOL_, DT_INST_STRING_TOKEN(inst, invert_output))
+
+#define STM32_COMP_DT_INST_BLANK_SEL(inst)	\
+	CONCAT(LL_COMP_BLANKINGSRC_, DT_INST_STRING_TOKEN(inst, st_blank_sel))
+
+#define STM32_COMP_DT_INST_LOCK(inst)		DT_INST_PROP(inst, st_lock_enable)
+
+#define STM32_COMP_DT_MILLER_EFFECT_HOLD_ENABLE(inst)	\
+	DT_INST_PROP(inst, st_miller_effect_hold_enable)
+
+#define STM32_COMP_DT_EXTI_LINE_NUMBER(inst)	DT_INST_PROP(inst, st_exti_line)
+
+#define STM32_COMP_DT_POWER_MODE(inst)	\
+	CONCAT(LL_COMP_POWERMODE_, DT_INST_STRING_TOKEN(inst, st_power_mode))
+
+#if DT_HAS_COMPAT_STATUS_OKAY(st_stm32h7_comp)
+#define STM32_COMP_DT_INST_COMP_CONFIG_INIT(inst)				\
+	{									\
+		.PowerMode = STM32_COMP_DT_POWER_MODE(inst),			\
+		.InputPlus = STM32_COMP_DT_INST_P_IN(inst),			\
+		.InputMinus = STM32_COMP_DT_INST_N_IN(inst),			\
+		.InputHysteresis = STM32_COMP_DT_INST_HYST_MODE(inst),		\
+		.OutputPolarity = STM32_COMP_DT_INST_INV_OUT(inst),		\
+		.OutputBlankingSource = STM32_COMP_DT_INST_BLANK_SEL(inst),	\
+	}
+#else /* st_stm32h7_comp */
+#define STM32_COMP_DT_INST_COMP_CONFIG_INIT(inst)				\
+	{									\
+		.InputPlus = STM32_COMP_DT_INST_P_IN(inst),			\
+		.InputMinus = STM32_COMP_DT_INST_N_IN(inst),			\
+		.InputHysteresis = STM32_COMP_DT_INST_HYST_MODE(inst),		\
+		.OutputPolarity = STM32_COMP_DT_INST_INV_OUT(inst),		\
+		.OutputBlankingSource = STM32_COMP_DT_INST_BLANK_SEL(inst),	\
+	}
+#endif /* st_stm32h7_comp */
+
+struct stm32_comp_config {
+	COMP_TypeDef *comp;
+	struct stm32_pclken *pclken;
+	const struct pinctrl_dev_config *pincfg;
+	void (*irq_init)(void);
+	const uint32_t irq_nr;
+	const LL_COMP_InitTypeDef comp_config;
+	const uint32_t exti_line_number;
+	const bool lock_enable;
+	const bool miller_effect_hold_enable;
+};
+
+struct stm32_comp_data {
+	comparator_callback_t callback;
+	void *user_data;
+};
+
+__maybe_unused static bool stm32_comp_is_resumed(void)
+{
+#if CONFIG_PM_DEVICE
+	enum pm_device_state state;
+
+	(void)pm_device_state_get(DEVICE_DT_INST_GET(0), &state);
+	return state == PM_DEVICE_STATE_ACTIVE;
+#else
+	return true;
+#endif /* CONFIG_PM_DEVICE */
+}
+
+static int stm32_comp_get_output(const struct device *dev)
+{
+	const struct stm32_comp_config *cfg = dev->config;
+
+	return LL_COMP_ReadOutputLevel(cfg->comp);
+}
+
+static int stm32_comp_set_trigger(const struct device *dev, enum comparator_trigger trigger)
+{
+	const struct stm32_comp_config *cfg = dev->config;
+	struct stm32_comp_data *data = dev->data;
+	stm32_exti_trigger_type exti_trigger = 0U;
+	int ret = 0;
+
+	switch (trigger) {
+	case COMPARATOR_TRIGGER_NONE:
+		exti_trigger = STM32_EXTI_TRIG_NONE;
+		break;
+	case COMPARATOR_TRIGGER_RISING_EDGE:
+		exti_trigger = STM32_EXTI_TRIG_RISING;
+		break;
+	case COMPARATOR_TRIGGER_FALLING_EDGE:
+		exti_trigger = STM32_EXTI_TRIG_FALLING;
+		break;
+	case COMPARATOR_TRIGGER_BOTH_EDGES:
+		exti_trigger = STM32_EXTI_TRIG_BOTH;
+		break;
+	default:
+		LOG_DBG("%s: Unsupported trigger mode %d", dev->name, trigger);
+		return -ENOTSUP;
+	}
+
+	irq_disable(cfg->irq_nr);
+	LL_COMP_Disable(cfg->comp);
+
+	ret = stm32_exti_enable(cfg->exti_line_number, exti_trigger,
+				STM32_EXTI_MODE_IT);
+	if (ret != 0) {
+		LOG_DBG("%s: EXTI init failed (%d)", dev->name, ret);
+		return ret;
+	}
+
+	if (stm32_comp_is_resumed()) {
+		LL_COMP_Enable(cfg->comp);
+	}
+
+	if (data->callback != NULL) {
+		irq_enable(cfg->irq_nr);
+	}
+
+	return ret;
+}
+
+static int stm32_comp_trigger_is_pending(const struct device *dev)
+{
+	const struct stm32_comp_config *cfg = dev->config;
+
+	if (stm32_exti_is_pending(cfg->exti_line_number)) {
+		stm32_exti_clear_pending(cfg->exti_line_number);
+		return 1;
+	}
+	return 0;
+}
+
+static int stm32_comp_set_trigger_callback(const struct device *dev, comparator_callback_t callback,
+					   void *user_data)
+{
+	const struct stm32_comp_config *cfg = dev->config;
+	struct stm32_comp_data *data = dev->data;
+
+	irq_disable(cfg->irq_nr);
+
+	data->callback = callback;
+	data->user_data = user_data;
+
+	irq_enable(cfg->irq_nr);
+
+	if (data->callback != NULL && stm32_comp_trigger_is_pending(dev)) {
+		callback(dev, user_data);
+	}
+
+	return 0;
+}
+
+static DEVICE_API(comparator, stm32_comp_comp_api) = {
+	.get_output = stm32_comp_get_output,
+	.set_trigger = stm32_comp_set_trigger,
+	.set_trigger_callback = stm32_comp_set_trigger_callback,
+	.trigger_is_pending = stm32_comp_trigger_is_pending,
+};
+
+static int stm32_comp_pm_callback(const struct device *dev, enum pm_device_action action)
+{
+	const struct stm32_comp_config *cfg = dev->config;
+
+	if (action == PM_DEVICE_ACTION_RESUME) {
+		if (cfg->lock_enable) {
+			LL_COMP_Lock(cfg->comp);
+		}
+		LL_COMP_Enable(cfg->comp);
+	}
+
+#if CONFIG_PM_DEVICE
+	if (action == PM_DEVICE_ACTION_SUSPEND) {
+		LL_COMP_Disable(cfg->comp);
+	}
+#endif
+
+	return 0;
+}
+
+static void stm32_comp_irq_handler(const struct device *dev)
+{
+	const struct stm32_comp_config *cfg = dev->config;
+	struct stm32_comp_data *data = dev->data;
+
+	if (stm32_exti_is_pending(cfg->exti_line_number)) {
+		stm32_exti_clear_pending(cfg->exti_line_number);
+	}
+
+	if (data->callback == NULL) {
+		return;
+	}
+
+	data->callback(dev, data->user_data);
+}
+
+static int stm32_comp_init(const struct device *dev)
+{
+	const struct device *const clk = DEVICE_DT_GET(STM32_CLOCK_CONTROL_NODE);
+	const struct stm32_comp_config *cfg = dev->config;
+	int ret = 0;
+
+	ret = device_is_ready(clk);
+	if (!ret) {
+		LOG_ERR("%s clock control device not ready (%d)", dev->name, ret);
+		return ret;
+	}
+
+	/* Enable COMP bus clock */
+	ret = clock_control_on(clk, &cfg->pclken[0]);
+	if (ret != 0) {
+		LOG_ERR("%s clock op failed (%d)", dev->name, ret);
+		return ret;
+	}
+
+	/* Enable COMP clock source */
+	clock_control_configure(clk, &cfg->pclken[1], NULL);
+	if (ret != 0) {
+		LOG_ERR("%s clock configure failed (%d)", dev->name, ret);
+		return ret;
+	}
+
+	/* Configure COMP inputs as specified in Device Tree, if any */
+	ret = pinctrl_apply_state(cfg->pincfg, PINCTRL_STATE_DEFAULT);
+	if (ret < 0 && ret != -ENOENT) {
+		/*
+		 * If the COMP is used only with internal channels, then no pinctrl is
+		 * provided in Device Tree, and pinctrl_apply_state returns -ENOENT,
+		 * but this should not be treated as an error.
+		 */
+		LOG_ERR("%s pinctrl setup failed (%d)", dev->name, ret);
+		return ret;
+	}
+
+	ret = LL_COMP_Init(cfg->comp, (LL_COMP_InitTypeDef *)&cfg->comp_config);
+	if (ret != 0) {
+		LOG_ERR("COMP instance is locked (%d)", ret);
+		return ret;
+	}
+
+	if (cfg->miller_effect_hold_enable) {
+#if defined(CONFIG_COMPARATOR_STM32_COMP_MILLER_EFFECT_HANDLING)
+		SET_BIT(cfg->comp->CSR, BIT(1U));
+#endif /* CONFIG_COMPARATOR_STM32_COMP_MILLER_EFFECT_HANDLING */
+	}
+
+	cfg->irq_init();
+
+	return pm_device_driver_init(dev, stm32_comp_pm_callback);
+}
+
+#define STM32_COMP_IRQ_HANDLER_SYM(inst)	_CONCAT(stm32_comp_irq_init, inst)
+
+#define STM32_COMP_IRQ_HANDLER_DEFINE(inst)				\
+	static void STM32_COMP_IRQ_HANDLER_SYM(inst)(void)		\
+	{							\
+		IRQ_CONNECT(DT_INST_IRQN(inst), DT_INST_IRQ(inst, priority), \
+			stm32_comp_irq_handler, DEVICE_DT_INST_GET(inst), 0); \
+		irq_enable(DT_INST_IRQN(inst));			\
+	}
+
+#define STM32_COMP_DEVICE(inst)						\
+	static struct stm32_pclken comp_clk[] = STM32_DT_INST_CLOCKS(inst); \
+	PINCTRL_DT_INST_DEFINE(inst);				\
+	static struct stm32_comp_data _CONCAT(data, inst);	\
+	STM32_COMP_IRQ_HANDLER_DEFINE(inst)			\
+	static const struct stm32_comp_config _CONCAT(config, inst) = { \
+		.comp = (COMP_TypeDef *)DT_INST_REG_ADDR(inst),	\
+		.pclken = comp_clk,				\
+		.pincfg = PINCTRL_DT_INST_DEV_CONFIG_GET(inst),	\
+		.irq_init = STM32_COMP_IRQ_HANDLER_SYM(inst),	\
+		.irq_nr = DT_INST_IRQN(inst),			\
+		.comp_config = STM32_COMP_DT_INST_COMP_CONFIG_INIT(inst), \
+		.exti_line_number = STM32_COMP_DT_EXTI_LINE_NUMBER(inst), \
+		.lock_enable = STM32_COMP_DT_INST_LOCK(inst),	\
+		.miller_effect_hold_enable = STM32_COMP_DT_MILLER_EFFECT_HOLD_ENABLE(inst) \
+	};							\
+	PM_DEVICE_DT_INST_DEFINE(inst, stm32_comp_pm_callback); \
+	DEVICE_DT_INST_DEFINE(inst, stm32_comp_init, PM_DEVICE_DT_INST_GET(inst), \
+				  &_CONCAT(data, inst), &_CONCAT(config, inst), POST_KERNEL, \
+				  CONFIG_COMPARATOR_INIT_PRIORITY, &stm32_comp_comp_api);
+
+DT_INST_FOREACH_STATUS_OKAY(STM32_COMP_DEVICE)