drivers/counter/stm32-timer-cnt.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /*
  * STM32 Timer Encoder and Counter driver
  *
  * Copyright (C) STMicroelectronics 2018
  *
  * Author: Benjamin Gaignard <benjamin.gaignard@st.com>
  *
  */
 #include <linux/counter.h>
 #include <linux/mfd/stm32-timers.h>
 #include <linux/mod_devicetable.h>
 #include <linux/module.h>
 #include <linux/pinctrl/consumer.h>
 #include <linux/platform_device.h>

 #define TIM_CCMR_CCXS	(BIT(8) | BIT(0))
 #define TIM_CCMR_MASK	(TIM_CCMR_CC1S | TIM_CCMR_CC2S | \
 			 TIM_CCMR_IC1F | TIM_CCMR_IC2F)
 #define TIM_CCER_MASK	(TIM_CCER_CC1P | TIM_CCER_CC1NP | \
 			 TIM_CCER_CC2P | TIM_CCER_CC2NP)

 struct stm32_timer_regs {
 	u32 cr1;
 	u32 cnt;
 	u32 smcr;
 	u32 arr;
 };

 struct stm32_timer_cnt {
 	struct counter_device counter;
 	struct regmap *regmap;
 	struct clk *clk;
 	u32 max_arr;
 	bool enabled;
 	struct stm32_timer_regs bak;
 };

 /**
  * enum stm32_count_function - enumerates stm32 timer counter encoder modes
  * @STM32_COUNT_SLAVE_MODE_DISABLED: counts on internal clock when CEN=1
  * @STM32_COUNT_ENCODER_MODE_1: counts TI1FP1 edges, depending on TI2FP2 level
  * @STM32_COUNT_ENCODER_MODE_2: counts TI2FP2 edges, depending on TI1FP1 level
  * @STM32_COUNT_ENCODER_MODE_3: counts on both TI1FP1 and TI2FP2 edges
  */
 enum stm32_count_function {
 	STM32_COUNT_SLAVE_MODE_DISABLED,
 	STM32_COUNT_ENCODER_MODE_1,
 	STM32_COUNT_ENCODER_MODE_2,
 	STM32_COUNT_ENCODER_MODE_3,
 };

 static const enum counter_function stm32_count_functions[] = {
 	[STM32_COUNT_SLAVE_MODE_DISABLED] = COUNTER_FUNCTION_INCREASE,
 	[STM32_COUNT_ENCODER_MODE_1] = COUNTER_FUNCTION_QUADRATURE_X2_A,
 	[STM32_COUNT_ENCODER_MODE_2] = COUNTER_FUNCTION_QUADRATURE_X2_B,
 	[STM32_COUNT_ENCODER_MODE_3] = COUNTER_FUNCTION_QUADRATURE_X4,
 };

 static int stm32_count_read(struct counter_device *counter,
 			    struct counter_count *count, unsigned long *val)
 {
 	struct stm32_timer_cnt *const priv = counter->priv;
 	u32 cnt;

 	regmap_read(priv->regmap, TIM_CNT, &cnt);
 	*val = cnt;

 	return 0;
 }

 static int stm32_count_write(struct counter_device *counter,
 			     struct counter_count *count,
 			     const unsigned long val)
 {
 	struct stm32_timer_cnt *const priv = counter->priv;
 	u32 ceiling;

 	regmap_read(priv->regmap, TIM_ARR, &ceiling);
 	if (val > ceiling)
 		return -EINVAL;

 	return regmap_write(priv->regmap, TIM_CNT, val);
 }

 static int stm32_count_function_get(struct counter_device *counter,
 				    struct counter_count *count,
 				    size_t *function)
 {
 	struct stm32_timer_cnt *const priv = counter->priv;
 	u32 smcr;

 	regmap_read(priv->regmap, TIM_SMCR, &smcr);

 	switch (smcr & TIM_SMCR_SMS) {
 	case 0:
 		*function = STM32_COUNT_SLAVE_MODE_DISABLED;
 		return 0;
 	case 1:
 		*function = STM32_COUNT_ENCODER_MODE_1;
 		return 0;
 	case 2:
 		*function = STM32_COUNT_ENCODER_MODE_2;
 		return 0;
 	case 3:
 		*function = STM32_COUNT_ENCODER_MODE_3;
 		return 0;
 	default:
 		return -EINVAL;
 	}
 }

 static int stm32_count_function_set(struct counter_device *counter,
 				    struct counter_count *count,
 				    size_t function)
 {
 	struct stm32_timer_cnt *const priv = counter->priv;
 	u32 cr1, sms;

 	switch (function) {
 	case STM32_COUNT_SLAVE_MODE_DISABLED:
 		sms = 0;
 		break;
 	case STM32_COUNT_ENCODER_MODE_1:
 		sms = 1;
 		break;
 	case STM32_COUNT_ENCODER_MODE_2:
 		sms = 2;
 		break;
 	case STM32_COUNT_ENCODER_MODE_3:
 		sms = 3;
 		break;
 	default:
 		return -EINVAL;
 	}

 	/* Store enable status */
 	regmap_read(priv->regmap, TIM_CR1, &cr1);

 	regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN, 0);

 	regmap_update_bits(priv->regmap, TIM_SMCR, TIM_SMCR_SMS, sms);

 	/* Make sure that registers are updated */
 	regmap_update_bits(priv->regmap, TIM_EGR, TIM_EGR_UG, TIM_EGR_UG);

 	/* Restore the enable status */
 	regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN, cr1);

 	return 0;
 }

 static ssize_t stm32_count_direction_read(struct counter_device *counter,
 				      struct counter_count *count,
 				      void *private, char *buf)
 {
 	struct stm32_timer_cnt *const priv = counter->priv;
 	const char *direction;
 	u32 cr1;

 	regmap_read(priv->regmap, TIM_CR1, &cr1);
 	direction = (cr1 & TIM_CR1_DIR) ? "backward" : "forward";

 	return scnprintf(buf, PAGE_SIZE, "%s\n", direction);
 }

 static ssize_t stm32_count_ceiling_read(struct counter_device *counter,
 					struct counter_count *count,
 					void *private, char *buf)
 {
 	struct stm32_timer_cnt *const priv = counter->priv;
 	u32 arr;

 	regmap_read(priv->regmap, TIM_ARR, &arr);

 	return snprintf(buf, PAGE_SIZE, "%u\n", arr);
 }

 static ssize_t stm32_count_ceiling_write(struct counter_device *counter,
 					 struct counter_count *count,
 					 void *private,
 					 const char *buf, size_t len)
 {
 	struct stm32_timer_cnt *const priv = counter->priv;
 	unsigned int ceiling;
 	int ret;

 	ret = kstrtouint(buf, 0, &ceiling);
 	if (ret)
 		return ret;

 	if (ceiling > priv->max_arr)
 		return -ERANGE;

 	/* TIMx_ARR register shouldn't be buffered (ARPE=0) */
 	regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_ARPE, 0);
 	regmap_write(priv->regmap, TIM_ARR, ceiling);

 	return len;
 }

 static ssize_t stm32_count_enable_read(struct counter_device *counter,
 				       struct counter_count *count,
 				       void *private, char *buf)
 {
 	struct stm32_timer_cnt *const priv = counter->priv;
 	u32 cr1;

 	regmap_read(priv->regmap, TIM_CR1, &cr1);

 	return scnprintf(buf, PAGE_SIZE, "%d\n", (bool)(cr1 & TIM_CR1_CEN));
 }

 static ssize_t stm32_count_enable_write(struct counter_device *counter,
 					struct counter_count *count,
 					void *private,
 					const char *buf, size_t len)
 {
 	struct stm32_timer_cnt *const priv = counter->priv;
 	int err;
 	u32 cr1;
 	bool enable;

 	err = kstrtobool(buf, &enable);
 	if (err)
 		return err;

 	if (enable) {
 		regmap_read(priv->regmap, TIM_CR1, &cr1);
 		if (!(cr1 & TIM_CR1_CEN))
 			clk_enable(priv->clk);

 		regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN,
 				   TIM_CR1_CEN);
 	} else {
 		regmap_read(priv->regmap, TIM_CR1, &cr1);
 		regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN, 0);
 		if (cr1 & TIM_CR1_CEN)
 			clk_disable(priv->clk);
 	}

 	/* Keep enabled state to properly handle low power states */
 	priv->enabled = enable;

 	return len;
 }

 static const struct counter_count_ext stm32_count_ext[] = {
 	{
 		.name = "direction",
 		.read = stm32_count_direction_read,
 	},
 	{
 		.name = "enable",
 		.read = stm32_count_enable_read,
 		.write = stm32_count_enable_write
 	},
 	{
 		.name = "ceiling",
 		.read = stm32_count_ceiling_read,
 		.write = stm32_count_ceiling_write
 	},
 };

 enum stm32_synapse_action {
 	STM32_SYNAPSE_ACTION_NONE,
 	STM32_SYNAPSE_ACTION_BOTH_EDGES
 };

 static const enum counter_synapse_action stm32_synapse_actions[] = {
 	[STM32_SYNAPSE_ACTION_NONE] = COUNTER_SYNAPSE_ACTION_NONE,
 	[STM32_SYNAPSE_ACTION_BOTH_EDGES] = COUNTER_SYNAPSE_ACTION_BOTH_EDGES
 };

 static int stm32_action_get(struct counter_device *counter,
 			    struct counter_count *count,
 			    struct counter_synapse *synapse,
 			    size_t *action)
 {
 	size_t function;
 	int err;

 	err = stm32_count_function_get(counter, count, &function);
 	if (err)
 		return err;

 	switch (function) {
 	case STM32_COUNT_SLAVE_MODE_DISABLED:
 		/* counts on internal clock when CEN=1 */
 		*action = STM32_SYNAPSE_ACTION_NONE;
 		return 0;
 	case STM32_COUNT_ENCODER_MODE_1:
 		/* counts up/down on TI1FP1 edge depending on TI2FP2 level */
 		if (synapse->signal->id == count->synapses[0].signal->id)
 			*action = STM32_SYNAPSE_ACTION_BOTH_EDGES;
 		else
 			*action = STM32_SYNAPSE_ACTION_NONE;
 		return 0;
 	case STM32_COUNT_ENCODER_MODE_2:
 		/* counts up/down on TI2FP2 edge depending on TI1FP1 level */
 		if (synapse->signal->id == count->synapses[1].signal->id)
 			*action = STM32_SYNAPSE_ACTION_BOTH_EDGES;
 		else
 			*action = STM32_SYNAPSE_ACTION_NONE;
 		return 0;
 	case STM32_COUNT_ENCODER_MODE_3:
 		/* counts up/down on both TI1FP1 and TI2FP2 edges */
 		*action = STM32_SYNAPSE_ACTION_BOTH_EDGES;
 		return 0;
 	default:
 		return -EINVAL;
 	}
 }

 static const struct counter_ops stm32_timer_cnt_ops = {
 	.count_read = stm32_count_read,
 	.count_write = stm32_count_write,
 	.function_get = stm32_count_function_get,
 	.function_set = stm32_count_function_set,
 	.action_get = stm32_action_get,
 };

 static struct counter_signal stm32_signals[] = {
 	{
 		.id = 0,
 		.name = "Channel 1 Quadrature A"
 	},
 	{
 		.id = 1,
 		.name = "Channel 1 Quadrature B"
 	}
 };

 static struct counter_synapse stm32_count_synapses[] = {
 	{
 		.actions_list = stm32_synapse_actions,
 		.num_actions = ARRAY_SIZE(stm32_synapse_actions),
 		.signal = &stm32_signals[0]
 	},
 	{
 		.actions_list = stm32_synapse_actions,
 		.num_actions = ARRAY_SIZE(stm32_synapse_actions),
 		.signal = &stm32_signals[1]
 	}
 };

 static struct counter_count stm32_counts = {
 	.id = 0,
 	.name = "Channel 1 Count",
 	.functions_list = stm32_count_functions,
 	.num_functions = ARRAY_SIZE(stm32_count_functions),
 	.synapses = stm32_count_synapses,
 	.num_synapses = ARRAY_SIZE(stm32_count_synapses),
 	.ext = stm32_count_ext,
 	.num_ext = ARRAY_SIZE(stm32_count_ext)
 };

 static int stm32_timer_cnt_probe(struct platform_device *pdev)
 {
 	struct stm32_timers *ddata = dev_get_drvdata(pdev->dev.parent);
 	struct device *dev = &pdev->dev;
 	struct stm32_timer_cnt *priv;

 	if (IS_ERR_OR_NULL(ddata))
 		return -EINVAL;

 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
 	if (!priv)
 		return -ENOMEM;

 	priv->regmap = ddata->regmap;
 	priv->clk = ddata->clk;
 	priv->max_arr = ddata->max_arr;

 	priv->counter.name = dev_name(dev);
 	priv->counter.parent = dev;
 	priv->counter.ops = &stm32_timer_cnt_ops;
 	priv->counter.counts = &stm32_counts;
 	priv->counter.num_counts = 1;
 	priv->counter.signals = stm32_signals;
 	priv->counter.num_signals = ARRAY_SIZE(stm32_signals);
 	priv->counter.priv = priv;

 	platform_set_drvdata(pdev, priv);

 	/* Register Counter device */
 	return devm_counter_register(dev, &priv->counter);
 }

 static int __maybe_unused stm32_timer_cnt_suspend(struct device *dev)
 {
 	struct stm32_timer_cnt *priv = dev_get_drvdata(dev);

 	/* Only take care of enabled counter: don't disturb other MFD child */
 	if (priv->enabled) {
 		/* Backup registers that may get lost in low power mode */
 		regmap_read(priv->regmap, TIM_SMCR, &priv->bak.smcr);
 		regmap_read(priv->regmap, TIM_ARR, &priv->bak.arr);
 		regmap_read(priv->regmap, TIM_CNT, &priv->bak.cnt);
 		regmap_read(priv->regmap, TIM_CR1, &priv->bak.cr1);

 		/* Disable the counter */
 		regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN, 0);
 		clk_disable(priv->clk);
 	}

 	return pinctrl_pm_select_sleep_state(dev);
 }

 static int __maybe_unused stm32_timer_cnt_resume(struct device *dev)
 {
 	struct stm32_timer_cnt *priv = dev_get_drvdata(dev);
 	int ret;

 	ret = pinctrl_pm_select_default_state(dev);
 	if (ret)
 		return ret;

 	if (priv->enabled) {
 		clk_enable(priv->clk);

 		/* Restore registers that may have been lost */
 		regmap_write(priv->regmap, TIM_SMCR, priv->bak.smcr);
 		regmap_write(priv->regmap, TIM_ARR, priv->bak.arr);
 		regmap_write(priv->regmap, TIM_CNT, priv->bak.cnt);

 		/* Also re-enables the counter */
 		regmap_write(priv->regmap, TIM_CR1, priv->bak.cr1);
 	}

 	return 0;
 }

 static SIMPLE_DEV_PM_OPS(stm32_timer_cnt_pm_ops, stm32_timer_cnt_suspend,
 			 stm32_timer_cnt_resume);

 static const struct of_device_id stm32_timer_cnt_of_match[] = {
 	{ .compatible = "st,stm32-timer-counter", },
 	{},
 };
 MODULE_DEVICE_TABLE(of, stm32_timer_cnt_of_match);

 static struct platform_driver stm32_timer_cnt_driver = {
 	.probe = stm32_timer_cnt_probe,
 	.driver = {
 		.name = "stm32-timer-counter",
 		.of_match_table = stm32_timer_cnt_of_match,
 		.pm = &stm32_timer_cnt_pm_ops,
 	},
 };
 module_platform_driver(stm32_timer_cnt_driver);

 MODULE_AUTHOR("Benjamin Gaignard <benjamin.gaignard@st.com>");
 MODULE_ALIAS("platform:stm32-timer-counter");
 MODULE_DESCRIPTION("STMicroelectronics STM32 TIMER counter driver");
 MODULE_LICENSE("GPL v2");
	// SPDX-License-Identifier: GPL-2.0
	/*
	* STM32 Timer Encoder and Counter driver
	*
	* Copyright (C) STMicroelectronics 2018
	*
	* Author: Benjamin Gaignard <benjamin.gaignard@st.com>
	*
	*/
	#include <linux/counter.h>
	#include <linux/mfd/stm32-timers.h>
	#include <linux/mod_devicetable.h>
	#include <linux/module.h>
	#include <linux/pinctrl/consumer.h>
	#include <linux/platform_device.h>

	#define TIM_CCMR_CCXS (BIT(8) \| BIT(0))
	#define TIM_CCMR_MASK (TIM_CCMR_CC1S \| TIM_CCMR_CC2S \| \
	TIM_CCMR_IC1F \| TIM_CCMR_IC2F)
	#define TIM_CCER_MASK (TIM_CCER_CC1P \| TIM_CCER_CC1NP \| \
	TIM_CCER_CC2P \| TIM_CCER_CC2NP)

	struct stm32_timer_regs {
	u32 cr1;
	u32 cnt;
	u32 smcr;
	u32 arr;
	};

	struct stm32_timer_cnt {
	struct counter_device counter;
	struct regmap *regmap;
	struct clk *clk;
	u32 max_arr;
	bool enabled;
	struct stm32_timer_regs bak;
	};

	/**
	* enum stm32_count_function - enumerates stm32 timer counter encoder modes
	* @STM32_COUNT_SLAVE_MODE_DISABLED: counts on internal clock when CEN=1
	* @STM32_COUNT_ENCODER_MODE_1: counts TI1FP1 edges, depending on TI2FP2 level
	* @STM32_COUNT_ENCODER_MODE_2: counts TI2FP2 edges, depending on TI1FP1 level
	* @STM32_COUNT_ENCODER_MODE_3: counts on both TI1FP1 and TI2FP2 edges
	*/
	enum stm32_count_function {
	STM32_COUNT_SLAVE_MODE_DISABLED,
	STM32_COUNT_ENCODER_MODE_1,
	STM32_COUNT_ENCODER_MODE_2,
	STM32_COUNT_ENCODER_MODE_3,
	};

	static const enum counter_function stm32_count_functions[] = {
	[STM32_COUNT_SLAVE_MODE_DISABLED] = COUNTER_FUNCTION_INCREASE,
	[STM32_COUNT_ENCODER_MODE_1] = COUNTER_FUNCTION_QUADRATURE_X2_A,
	[STM32_COUNT_ENCODER_MODE_2] = COUNTER_FUNCTION_QUADRATURE_X2_B,
	[STM32_COUNT_ENCODER_MODE_3] = COUNTER_FUNCTION_QUADRATURE_X4,
	};

	static int stm32_count_read(struct counter_device *counter,
	struct counter_count count, unsigned long val)
	{
	struct stm32_timer_cnt *const priv = counter->priv;
	u32 cnt;

	regmap_read(priv->regmap, TIM_CNT, &cnt);
	*val = cnt;

	return 0;
	}

	static int stm32_count_write(struct counter_device *counter,
	struct counter_count *count,
	const unsigned long val)
	{
	struct stm32_timer_cnt *const priv = counter->priv;
	u32 ceiling;

	regmap_read(priv->regmap, TIM_ARR, &ceiling);
	if (val > ceiling)
	return -EINVAL;

	return regmap_write(priv->regmap, TIM_CNT, val);
	}

	static int stm32_count_function_get(struct counter_device *counter,
	struct counter_count *count,
	size_t *function)
	{
	struct stm32_timer_cnt *const priv = counter->priv;
	u32 smcr;

	regmap_read(priv->regmap, TIM_SMCR, &smcr);

	switch (smcr & TIM_SMCR_SMS) {
	case 0:
	*function = STM32_COUNT_SLAVE_MODE_DISABLED;
	return 0;
	case 1:
	*function = STM32_COUNT_ENCODER_MODE_1;
	return 0;
	case 2:
	*function = STM32_COUNT_ENCODER_MODE_2;
	return 0;
	case 3:
	*function = STM32_COUNT_ENCODER_MODE_3;
	return 0;
	default:
	return -EINVAL;
	}
	}

	static int stm32_count_function_set(struct counter_device *counter,
	struct counter_count *count,
	size_t function)
	{
	struct stm32_timer_cnt *const priv = counter->priv;
	u32 cr1, sms;

	switch (function) {
	case STM32_COUNT_SLAVE_MODE_DISABLED:
	sms = 0;
	break;
	case STM32_COUNT_ENCODER_MODE_1:
	sms = 1;
	break;
	case STM32_COUNT_ENCODER_MODE_2:
	sms = 2;
	break;
	case STM32_COUNT_ENCODER_MODE_3:
	sms = 3;
	break;
	default:
	return -EINVAL;
	}

	/* Store enable status */
	regmap_read(priv->regmap, TIM_CR1, &cr1);

	regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN, 0);

	regmap_update_bits(priv->regmap, TIM_SMCR, TIM_SMCR_SMS, sms);

	/* Make sure that registers are updated */
	regmap_update_bits(priv->regmap, TIM_EGR, TIM_EGR_UG, TIM_EGR_UG);

	/* Restore the enable status */
	regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN, cr1);

	return 0;
	}

	static ssize_t stm32_count_direction_read(struct counter_device *counter,
	struct counter_count *count,
	void private, char buf)
	{
	struct stm32_timer_cnt *const priv = counter->priv;
	const char *direction;
	u32 cr1;

	regmap_read(priv->regmap, TIM_CR1, &cr1);
	direction = (cr1 & TIM_CR1_DIR) ? "backward" : "forward";

	return scnprintf(buf, PAGE_SIZE, "%s\n", direction);
	}

	static ssize_t stm32_count_ceiling_read(struct counter_device *counter,
	struct counter_count *count,
	void private, char buf)
	{
	struct stm32_timer_cnt *const priv = counter->priv;
	u32 arr;

	regmap_read(priv->regmap, TIM_ARR, &arr);

	return snprintf(buf, PAGE_SIZE, "%u\n", arr);
	}

	static ssize_t stm32_count_ceiling_write(struct counter_device *counter,
	struct counter_count *count,
	void *private,
	const char *buf, size_t len)
	{
	struct stm32_timer_cnt *const priv = counter->priv;
	unsigned int ceiling;
	int ret;

	ret = kstrtouint(buf, 0, &ceiling);
	if (ret)
	return ret;

	if (ceiling > priv->max_arr)
	return -ERANGE;

	/* TIMx_ARR register shouldn't be buffered (ARPE=0) */
	regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_ARPE, 0);
	regmap_write(priv->regmap, TIM_ARR, ceiling);

	return len;
	}

	static ssize_t stm32_count_enable_read(struct counter_device *counter,
	struct counter_count *count,
	void private, char buf)
	{
	struct stm32_timer_cnt *const priv = counter->priv;
	u32 cr1;

	regmap_read(priv->regmap, TIM_CR1, &cr1);

	return scnprintf(buf, PAGE_SIZE, "%d\n", (bool)(cr1 & TIM_CR1_CEN));
	}

	static ssize_t stm32_count_enable_write(struct counter_device *counter,
	struct counter_count *count,
	void *private,
	const char *buf, size_t len)
	{
	struct stm32_timer_cnt *const priv = counter->priv;
	int err;
	u32 cr1;
	bool enable;

	err = kstrtobool(buf, &enable);
	if (err)
	return err;

	if (enable) {
	regmap_read(priv->regmap, TIM_CR1, &cr1);
	if (!(cr1 & TIM_CR1_CEN))
	clk_enable(priv->clk);

	regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN,
	TIM_CR1_CEN);
	} else {
	regmap_read(priv->regmap, TIM_CR1, &cr1);
	regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN, 0);
	if (cr1 & TIM_CR1_CEN)
	clk_disable(priv->clk);
	}

	/* Keep enabled state to properly handle low power states */
	priv->enabled = enable;

	return len;
	}

	static const struct counter_count_ext stm32_count_ext[] = {
	{
	.name = "direction",
	.read = stm32_count_direction_read,
	},
	{
	.name = "enable",
	.read = stm32_count_enable_read,
	.write = stm32_count_enable_write
	},
	{
	.name = "ceiling",
	.read = stm32_count_ceiling_read,
	.write = stm32_count_ceiling_write
	},
	};

	enum stm32_synapse_action {
	STM32_SYNAPSE_ACTION_NONE,
	STM32_SYNAPSE_ACTION_BOTH_EDGES
	};

	static const enum counter_synapse_action stm32_synapse_actions[] = {
	[STM32_SYNAPSE_ACTION_NONE] = COUNTER_SYNAPSE_ACTION_NONE,
	[STM32_SYNAPSE_ACTION_BOTH_EDGES] = COUNTER_SYNAPSE_ACTION_BOTH_EDGES
	};

	static int stm32_action_get(struct counter_device *counter,
	struct counter_count *count,
	struct counter_synapse *synapse,
	size_t *action)
	{
	size_t function;
	int err;

	err = stm32_count_function_get(counter, count, &function);
	if (err)
	return err;

	switch (function) {
	case STM32_COUNT_SLAVE_MODE_DISABLED:
	/* counts on internal clock when CEN=1 */
	*action = STM32_SYNAPSE_ACTION_NONE;
	return 0;
	case STM32_COUNT_ENCODER_MODE_1:
	/* counts up/down on TI1FP1 edge depending on TI2FP2 level */
	if (synapse->signal->id == count->synapses[0].signal->id)
	*action = STM32_SYNAPSE_ACTION_BOTH_EDGES;
	else
	*action = STM32_SYNAPSE_ACTION_NONE;
	return 0;
	case STM32_COUNT_ENCODER_MODE_2:
	/* counts up/down on TI2FP2 edge depending on TI1FP1 level */
	if (synapse->signal->id == count->synapses[1].signal->id)
	*action = STM32_SYNAPSE_ACTION_BOTH_EDGES;
	else
	*action = STM32_SYNAPSE_ACTION_NONE;
	return 0;
	case STM32_COUNT_ENCODER_MODE_3:
	/* counts up/down on both TI1FP1 and TI2FP2 edges */
	*action = STM32_SYNAPSE_ACTION_BOTH_EDGES;
	return 0;
	default:
	return -EINVAL;
	}
	}

	static const struct counter_ops stm32_timer_cnt_ops = {
	.count_read = stm32_count_read,
	.count_write = stm32_count_write,
	.function_get = stm32_count_function_get,
	.function_set = stm32_count_function_set,
	.action_get = stm32_action_get,
	};

	static struct counter_signal stm32_signals[] = {
	{
	.id = 0,
	.name = "Channel 1 Quadrature A"
	},
	{
	.id = 1,
	.name = "Channel 1 Quadrature B"
	}
	};

	static struct counter_synapse stm32_count_synapses[] = {
	{
	.actions_list = stm32_synapse_actions,
	.num_actions = ARRAY_SIZE(stm32_synapse_actions),
	.signal = &stm32_signals[0]
	},
	{
	.actions_list = stm32_synapse_actions,
	.num_actions = ARRAY_SIZE(stm32_synapse_actions),
	.signal = &stm32_signals[1]
	}
	};

	static struct counter_count stm32_counts = {
	.id = 0,
	.name = "Channel 1 Count",
	.functions_list = stm32_count_functions,
	.num_functions = ARRAY_SIZE(stm32_count_functions),
	.synapses = stm32_count_synapses,
	.num_synapses = ARRAY_SIZE(stm32_count_synapses),
	.ext = stm32_count_ext,
	.num_ext = ARRAY_SIZE(stm32_count_ext)
	};

	static int stm32_timer_cnt_probe(struct platform_device *pdev)
	{
	struct stm32_timers *ddata = dev_get_drvdata(pdev->dev.parent);
	struct device *dev = &pdev->dev;
	struct stm32_timer_cnt *priv;

	if (IS_ERR_OR_NULL(ddata))
	return -EINVAL;

	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
	if (!priv)
	return -ENOMEM;

	priv->regmap = ddata->regmap;
	priv->clk = ddata->clk;
	priv->max_arr = ddata->max_arr;

	priv->counter.name = dev_name(dev);
	priv->counter.parent = dev;
	priv->counter.ops = &stm32_timer_cnt_ops;
	priv->counter.counts = &stm32_counts;
	priv->counter.num_counts = 1;
	priv->counter.signals = stm32_signals;
	priv->counter.num_signals = ARRAY_SIZE(stm32_signals);
	priv->counter.priv = priv;

	platform_set_drvdata(pdev, priv);

	/* Register Counter device */
	return devm_counter_register(dev, &priv->counter);
	}

	static int __maybe_unused stm32_timer_cnt_suspend(struct device *dev)
	{
	struct stm32_timer_cnt *priv = dev_get_drvdata(dev);

	/* Only take care of enabled counter: don't disturb other MFD child */
	if (priv->enabled) {
	/* Backup registers that may get lost in low power mode */
	regmap_read(priv->regmap, TIM_SMCR, &priv->bak.smcr);
	regmap_read(priv->regmap, TIM_ARR, &priv->bak.arr);
	regmap_read(priv->regmap, TIM_CNT, &priv->bak.cnt);
	regmap_read(priv->regmap, TIM_CR1, &priv->bak.cr1);

	/* Disable the counter */
	regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN, 0);
	clk_disable(priv->clk);
	}

	return pinctrl_pm_select_sleep_state(dev);
	}

	static int __maybe_unused stm32_timer_cnt_resume(struct device *dev)
	{
	struct stm32_timer_cnt *priv = dev_get_drvdata(dev);
	int ret;

	ret = pinctrl_pm_select_default_state(dev);
	if (ret)
	return ret;

	if (priv->enabled) {
	clk_enable(priv->clk);

	/* Restore registers that may have been lost */
	regmap_write(priv->regmap, TIM_SMCR, priv->bak.smcr);
	regmap_write(priv->regmap, TIM_ARR, priv->bak.arr);
	regmap_write(priv->regmap, TIM_CNT, priv->bak.cnt);

	/* Also re-enables the counter */
	regmap_write(priv->regmap, TIM_CR1, priv->bak.cr1);
	}

	return 0;
	}

	static SIMPLE_DEV_PM_OPS(stm32_timer_cnt_pm_ops, stm32_timer_cnt_suspend,
	stm32_timer_cnt_resume);

	static const struct of_device_id stm32_timer_cnt_of_match[] = {
	{ .compatible = "st,stm32-timer-counter", },
	{},
	};
	MODULE_DEVICE_TABLE(of, stm32_timer_cnt_of_match);

	static struct platform_driver stm32_timer_cnt_driver = {
	.probe = stm32_timer_cnt_probe,
	.driver = {
	.name = "stm32-timer-counter",
	.of_match_table = stm32_timer_cnt_of_match,
	.pm = &stm32_timer_cnt_pm_ops,
	},
	};
	module_platform_driver(stm32_timer_cnt_driver);

	MODULE_AUTHOR("Benjamin Gaignard <benjamin.gaignard@st.com>");
	MODULE_ALIAS("platform:stm32-timer-counter");
	MODULE_DESCRIPTION("STMicroelectronics STM32 TIMER counter driver");
	MODULE_LICENSE("GPL v2");