| // SPDX-License-Identifier: GPL-2.0-only | 
 | /* | 
 |  * Copyright (C) 2020 Microchip | 
 |  * | 
 |  * Author: Kamel Bouhara <kamel.bouhara@bootlin.com> | 
 |  */ | 
 | #include <linux/clk.h> | 
 | #include <linux/counter.h> | 
 | #include <linux/mfd/syscon.h> | 
 | #include <linux/module.h> | 
 | #include <linux/mutex.h> | 
 | #include <linux/of.h> | 
 | #include <linux/platform_device.h> | 
 | #include <linux/regmap.h> | 
 | #include <soc/at91/atmel_tcb.h> | 
 |  | 
 | #define ATMEL_TC_CMR_MASK	(ATMEL_TC_LDRA_RISING | ATMEL_TC_LDRB_FALLING | \ | 
 | 				 ATMEL_TC_ETRGEDG_RISING | ATMEL_TC_LDBDIS | \ | 
 | 				 ATMEL_TC_LDBSTOP) | 
 |  | 
 | #define ATMEL_TC_QDEN			BIT(8) | 
 | #define ATMEL_TC_POSEN			BIT(9) | 
 |  | 
 | struct mchp_tc_data { | 
 | 	const struct atmel_tcb_config *tc_cfg; | 
 | 	struct regmap *regmap; | 
 | 	int qdec_mode; | 
 | 	int num_channels; | 
 | 	int channel[2]; | 
 | }; | 
 |  | 
 | static const enum counter_function mchp_tc_count_functions[] = { | 
 | 	COUNTER_FUNCTION_INCREASE, | 
 | 	COUNTER_FUNCTION_QUADRATURE_X4, | 
 | }; | 
 |  | 
 | static const enum counter_synapse_action mchp_tc_synapse_actions[] = { | 
 | 	COUNTER_SYNAPSE_ACTION_NONE, | 
 | 	COUNTER_SYNAPSE_ACTION_RISING_EDGE, | 
 | 	COUNTER_SYNAPSE_ACTION_FALLING_EDGE, | 
 | 	COUNTER_SYNAPSE_ACTION_BOTH_EDGES, | 
 | }; | 
 |  | 
 | static struct counter_signal mchp_tc_count_signals[] = { | 
 | 	{ | 
 | 		.id = 0, | 
 | 		.name = "Channel A", | 
 | 	}, | 
 | 	{ | 
 | 		.id = 1, | 
 | 		.name = "Channel B", | 
 | 	} | 
 | }; | 
 |  | 
 | static struct counter_synapse mchp_tc_count_synapses[] = { | 
 | 	{ | 
 | 		.actions_list = mchp_tc_synapse_actions, | 
 | 		.num_actions = ARRAY_SIZE(mchp_tc_synapse_actions), | 
 | 		.signal = &mchp_tc_count_signals[0] | 
 | 	}, | 
 | 	{ | 
 | 		.actions_list = mchp_tc_synapse_actions, | 
 | 		.num_actions = ARRAY_SIZE(mchp_tc_synapse_actions), | 
 | 		.signal = &mchp_tc_count_signals[1] | 
 | 	} | 
 | }; | 
 |  | 
 | static int mchp_tc_count_function_read(struct counter_device *counter, | 
 | 				       struct counter_count *count, | 
 | 				       enum counter_function *function) | 
 | { | 
 | 	struct mchp_tc_data *const priv = counter_priv(counter); | 
 |  | 
 | 	if (priv->qdec_mode) | 
 | 		*function = COUNTER_FUNCTION_QUADRATURE_X4; | 
 | 	else | 
 | 		*function = COUNTER_FUNCTION_INCREASE; | 
 |  | 
 | 	return 0; | 
 | } | 
 |  | 
 | static int mchp_tc_count_function_write(struct counter_device *counter, | 
 | 					struct counter_count *count, | 
 | 					enum counter_function function) | 
 | { | 
 | 	struct mchp_tc_data *const priv = counter_priv(counter); | 
 | 	u32 bmr, cmr; | 
 |  | 
 | 	regmap_read(priv->regmap, ATMEL_TC_BMR, &bmr); | 
 | 	regmap_read(priv->regmap, ATMEL_TC_REG(priv->channel[0], CMR), &cmr); | 
 |  | 
 | 	/* Set capture mode */ | 
 | 	cmr &= ~ATMEL_TC_WAVE; | 
 |  | 
 | 	switch (function) { | 
 | 	case COUNTER_FUNCTION_INCREASE: | 
 | 		priv->qdec_mode = 0; | 
 | 		/* Set highest rate based on whether soc has gclk or not */ | 
 | 		bmr &= ~(ATMEL_TC_QDEN | ATMEL_TC_POSEN); | 
 | 		if (!priv->tc_cfg->has_gclk) | 
 | 			cmr |= ATMEL_TC_TIMER_CLOCK2; | 
 | 		else | 
 | 			cmr |= ATMEL_TC_TIMER_CLOCK1; | 
 | 		/* Setup the period capture mode */ | 
 | 		cmr |=  ATMEL_TC_CMR_MASK; | 
 | 		cmr &= ~(ATMEL_TC_ABETRG | ATMEL_TC_XC0); | 
 | 		break; | 
 | 	case COUNTER_FUNCTION_QUADRATURE_X4: | 
 | 		if (!priv->tc_cfg->has_qdec) | 
 | 			return -EINVAL; | 
 | 		/* In QDEC mode settings both channels 0 and 1 are required */ | 
 | 		if (priv->num_channels < 2 || priv->channel[0] != 0 || | 
 | 		    priv->channel[1] != 1) { | 
 | 			pr_err("Invalid channels number or id for quadrature mode\n"); | 
 | 			return -EINVAL; | 
 | 		} | 
 | 		priv->qdec_mode = 1; | 
 | 		bmr |= ATMEL_TC_QDEN | ATMEL_TC_POSEN; | 
 | 		cmr |= ATMEL_TC_ETRGEDG_RISING | ATMEL_TC_ABETRG | ATMEL_TC_XC0; | 
 | 		break; | 
 | 	default: | 
 | 		/* should never reach this path */ | 
 | 		return -EINVAL; | 
 | 	} | 
 |  | 
 | 	regmap_write(priv->regmap, ATMEL_TC_BMR, bmr); | 
 | 	regmap_write(priv->regmap, ATMEL_TC_REG(priv->channel[0], CMR), cmr); | 
 |  | 
 | 	/* Enable clock and trigger counter */ | 
 | 	regmap_write(priv->regmap, ATMEL_TC_REG(priv->channel[0], CCR), | 
 | 		     ATMEL_TC_CLKEN | ATMEL_TC_SWTRG); | 
 |  | 
 | 	if (priv->qdec_mode) { | 
 | 		regmap_write(priv->regmap, | 
 | 			     ATMEL_TC_REG(priv->channel[1], CMR), cmr); | 
 | 		regmap_write(priv->regmap, | 
 | 			     ATMEL_TC_REG(priv->channel[1], CCR), | 
 | 			     ATMEL_TC_CLKEN | ATMEL_TC_SWTRG); | 
 | 	} | 
 |  | 
 | 	return 0; | 
 | } | 
 |  | 
 | static int mchp_tc_count_signal_read(struct counter_device *counter, | 
 | 				     struct counter_signal *signal, | 
 | 				     enum counter_signal_level *lvl) | 
 | { | 
 | 	struct mchp_tc_data *const priv = counter_priv(counter); | 
 | 	bool sigstatus; | 
 | 	u32 sr; | 
 |  | 
 | 	regmap_read(priv->regmap, ATMEL_TC_REG(priv->channel[0], SR), &sr); | 
 |  | 
 | 	if (signal->id == 1) | 
 | 		sigstatus = (sr & ATMEL_TC_MTIOB); | 
 | 	else | 
 | 		sigstatus = (sr & ATMEL_TC_MTIOA); | 
 |  | 
 | 	*lvl = sigstatus ? COUNTER_SIGNAL_LEVEL_HIGH : COUNTER_SIGNAL_LEVEL_LOW; | 
 |  | 
 | 	return 0; | 
 | } | 
 |  | 
 | static int mchp_tc_count_action_read(struct counter_device *counter, | 
 | 				     struct counter_count *count, | 
 | 				     struct counter_synapse *synapse, | 
 | 				     enum counter_synapse_action *action) | 
 | { | 
 | 	struct mchp_tc_data *const priv = counter_priv(counter); | 
 | 	u32 cmr; | 
 |  | 
 | 	if (priv->qdec_mode) { | 
 | 		*action = COUNTER_SYNAPSE_ACTION_BOTH_EDGES; | 
 | 		return 0; | 
 | 	} | 
 |  | 
 | 	/* Only TIOA signal is evaluated in non-QDEC mode */ | 
 | 	if (synapse->signal->id != 0) { | 
 | 		*action = COUNTER_SYNAPSE_ACTION_NONE; | 
 | 		return 0; | 
 | 	} | 
 |  | 
 | 	regmap_read(priv->regmap, ATMEL_TC_REG(priv->channel[0], CMR), &cmr); | 
 |  | 
 | 	switch (cmr & ATMEL_TC_ETRGEDG) { | 
 | 	default: | 
 | 		*action = COUNTER_SYNAPSE_ACTION_NONE; | 
 | 		break; | 
 | 	case ATMEL_TC_ETRGEDG_RISING: | 
 | 		*action = COUNTER_SYNAPSE_ACTION_RISING_EDGE; | 
 | 		break; | 
 | 	case ATMEL_TC_ETRGEDG_FALLING: | 
 | 		*action = COUNTER_SYNAPSE_ACTION_FALLING_EDGE; | 
 | 		break; | 
 | 	case ATMEL_TC_ETRGEDG_BOTH: | 
 | 		*action = COUNTER_SYNAPSE_ACTION_BOTH_EDGES; | 
 | 		break; | 
 | 	} | 
 |  | 
 | 	return 0; | 
 | } | 
 |  | 
 | static int mchp_tc_count_action_write(struct counter_device *counter, | 
 | 				      struct counter_count *count, | 
 | 				      struct counter_synapse *synapse, | 
 | 				      enum counter_synapse_action action) | 
 | { | 
 | 	struct mchp_tc_data *const priv = counter_priv(counter); | 
 | 	u32 edge = ATMEL_TC_ETRGEDG_NONE; | 
 |  | 
 | 	/* QDEC mode is rising edge only; only TIOA handled in non-QDEC mode */ | 
 | 	if (priv->qdec_mode || synapse->signal->id != 0) | 
 | 		return -EINVAL; | 
 |  | 
 | 	switch (action) { | 
 | 	case COUNTER_SYNAPSE_ACTION_NONE: | 
 | 		edge = ATMEL_TC_ETRGEDG_NONE; | 
 | 		break; | 
 | 	case COUNTER_SYNAPSE_ACTION_RISING_EDGE: | 
 | 		edge = ATMEL_TC_ETRGEDG_RISING; | 
 | 		break; | 
 | 	case COUNTER_SYNAPSE_ACTION_FALLING_EDGE: | 
 | 		edge = ATMEL_TC_ETRGEDG_FALLING; | 
 | 		break; | 
 | 	case COUNTER_SYNAPSE_ACTION_BOTH_EDGES: | 
 | 		edge = ATMEL_TC_ETRGEDG_BOTH; | 
 | 		break; | 
 | 	default: | 
 | 		/* should never reach this path */ | 
 | 		return -EINVAL; | 
 | 	} | 
 |  | 
 | 	return regmap_write_bits(priv->regmap, | 
 | 				ATMEL_TC_REG(priv->channel[0], CMR), | 
 | 				ATMEL_TC_ETRGEDG, edge); | 
 | } | 
 |  | 
 | static int mchp_tc_count_read(struct counter_device *counter, | 
 | 			      struct counter_count *count, u64 *val) | 
 | { | 
 | 	struct mchp_tc_data *const priv = counter_priv(counter); | 
 | 	u32 cnt; | 
 |  | 
 | 	regmap_read(priv->regmap, ATMEL_TC_REG(priv->channel[0], CV), &cnt); | 
 | 	*val = cnt; | 
 |  | 
 | 	return 0; | 
 | } | 
 |  | 
 | static struct counter_count mchp_tc_counts[] = { | 
 | 	{ | 
 | 		.id = 0, | 
 | 		.name = "Timer Counter", | 
 | 		.functions_list = mchp_tc_count_functions, | 
 | 		.num_functions = ARRAY_SIZE(mchp_tc_count_functions), | 
 | 		.synapses = mchp_tc_count_synapses, | 
 | 		.num_synapses = ARRAY_SIZE(mchp_tc_count_synapses), | 
 | 	}, | 
 | }; | 
 |  | 
 | static const struct counter_ops mchp_tc_ops = { | 
 | 	.signal_read    = mchp_tc_count_signal_read, | 
 | 	.count_read     = mchp_tc_count_read, | 
 | 	.function_read  = mchp_tc_count_function_read, | 
 | 	.function_write = mchp_tc_count_function_write, | 
 | 	.action_read    = mchp_tc_count_action_read, | 
 | 	.action_write   = mchp_tc_count_action_write | 
 | }; | 
 |  | 
 | static const struct atmel_tcb_config tcb_rm9200_config = { | 
 | 		.counter_width = 16, | 
 | }; | 
 |  | 
 | static const struct atmel_tcb_config tcb_sam9x5_config = { | 
 | 		.counter_width = 32, | 
 | }; | 
 |  | 
 | static const struct atmel_tcb_config tcb_sama5d2_config = { | 
 | 		.counter_width = 32, | 
 | 		.has_gclk = true, | 
 | 		.has_qdec = true, | 
 | }; | 
 |  | 
 | static const struct atmel_tcb_config tcb_sama5d3_config = { | 
 | 		.counter_width = 32, | 
 | 		.has_qdec = true, | 
 | }; | 
 |  | 
 | static const struct of_device_id atmel_tc_of_match[] = { | 
 | 	{ .compatible = "atmel,at91rm9200-tcb", .data = &tcb_rm9200_config, }, | 
 | 	{ .compatible = "atmel,at91sam9x5-tcb", .data = &tcb_sam9x5_config, }, | 
 | 	{ .compatible = "atmel,sama5d2-tcb", .data = &tcb_sama5d2_config, }, | 
 | 	{ .compatible = "atmel,sama5d3-tcb", .data = &tcb_sama5d3_config, }, | 
 | 	{ /* sentinel */ } | 
 | }; | 
 |  | 
 | static void mchp_tc_clk_remove(void *ptr) | 
 | { | 
 | 	clk_disable_unprepare((struct clk *)ptr); | 
 | } | 
 |  | 
 | static int mchp_tc_probe(struct platform_device *pdev) | 
 | { | 
 | 	struct device_node *np = pdev->dev.of_node; | 
 | 	const struct atmel_tcb_config *tcb_config; | 
 | 	const struct of_device_id *match; | 
 | 	struct counter_device *counter; | 
 | 	struct mchp_tc_data *priv; | 
 | 	char clk_name[7]; | 
 | 	struct regmap *regmap; | 
 | 	struct clk *clk[3]; | 
 | 	int channel; | 
 | 	int ret, i; | 
 |  | 
 | 	counter = devm_counter_alloc(&pdev->dev, sizeof(*priv)); | 
 | 	if (!counter) | 
 | 		return -ENOMEM; | 
 | 	priv = counter_priv(counter); | 
 |  | 
 | 	match = of_match_node(atmel_tc_of_match, np->parent); | 
 | 	tcb_config = match->data; | 
 | 	if (!tcb_config) { | 
 | 		dev_err(&pdev->dev, "No matching parent node found\n"); | 
 | 		return -ENODEV; | 
 | 	} | 
 |  | 
 | 	regmap = syscon_node_to_regmap(np->parent); | 
 | 	if (IS_ERR(regmap)) | 
 | 		return PTR_ERR(regmap); | 
 |  | 
 | 	/* max. channels number is 2 when in QDEC mode */ | 
 | 	priv->num_channels = of_property_count_u32_elems(np, "reg"); | 
 | 	if (priv->num_channels < 0) { | 
 | 		dev_err(&pdev->dev, "Invalid or missing channel\n"); | 
 | 		return -EINVAL; | 
 | 	} | 
 |  | 
 | 	/* Register channels and initialize clocks */ | 
 | 	for (i = 0; i < priv->num_channels; i++) { | 
 | 		ret = of_property_read_u32_index(np, "reg", i, &channel); | 
 | 		if (ret < 0 || channel > 2) | 
 | 			return -ENODEV; | 
 |  | 
 | 		priv->channel[i] = channel; | 
 |  | 
 | 		snprintf(clk_name, sizeof(clk_name), "t%d_clk", channel); | 
 |  | 
 | 		clk[i] = of_clk_get_by_name(np->parent, clk_name); | 
 | 		if (IS_ERR(clk[i])) { | 
 | 			/* Fallback to t0_clk */ | 
 | 			clk[i] = of_clk_get_by_name(np->parent, "t0_clk"); | 
 | 			if (IS_ERR(clk[i])) | 
 | 				return PTR_ERR(clk[i]); | 
 | 		} | 
 |  | 
 | 		ret = clk_prepare_enable(clk[i]); | 
 | 		if (ret) | 
 | 			return ret; | 
 |  | 
 | 		ret = devm_add_action_or_reset(&pdev->dev, | 
 | 					       mchp_tc_clk_remove, | 
 | 					       clk[i]); | 
 | 		if (ret) | 
 | 			return ret; | 
 |  | 
 | 		dev_dbg(&pdev->dev, | 
 | 			"Initialized capture mode on channel %d\n", | 
 | 			channel); | 
 | 	} | 
 |  | 
 | 	priv->tc_cfg = tcb_config; | 
 | 	priv->regmap = regmap; | 
 | 	counter->name = dev_name(&pdev->dev); | 
 | 	counter->parent = &pdev->dev; | 
 | 	counter->ops = &mchp_tc_ops; | 
 | 	counter->num_counts = ARRAY_SIZE(mchp_tc_counts); | 
 | 	counter->counts = mchp_tc_counts; | 
 | 	counter->num_signals = ARRAY_SIZE(mchp_tc_count_signals); | 
 | 	counter->signals = mchp_tc_count_signals; | 
 |  | 
 | 	ret = devm_counter_add(&pdev->dev, counter); | 
 | 	if (ret < 0) | 
 | 		return dev_err_probe(&pdev->dev, ret, "Failed to add counter\n"); | 
 |  | 
 | 	return 0; | 
 | } | 
 |  | 
 | static const struct of_device_id mchp_tc_dt_ids[] = { | 
 | 	{ .compatible = "microchip,tcb-capture", }, | 
 | 	{ /* sentinel */ }, | 
 | }; | 
 | MODULE_DEVICE_TABLE(of, mchp_tc_dt_ids); | 
 |  | 
 | static struct platform_driver mchp_tc_driver = { | 
 | 	.probe = mchp_tc_probe, | 
 | 	.driver = { | 
 | 		.name = "microchip-tcb-capture", | 
 | 		.of_match_table = mchp_tc_dt_ids, | 
 | 	}, | 
 | }; | 
 | module_platform_driver(mchp_tc_driver); | 
 |  | 
 | MODULE_AUTHOR("Kamel Bouhara <kamel.bouhara@bootlin.com>"); | 
 | MODULE_DESCRIPTION("Microchip TCB Capture driver"); | 
 | MODULE_LICENSE("GPL v2"); | 
 | MODULE_IMPORT_NS(COUNTER); |