1 files changed, 407 insertions, 0 deletions

diff --git a/drivers/counter/microchip-tcb-capture.c b/drivers/counter/microchip-tcb-capture.c
new file mode 100644
index 000000000..c7af13aca
--- /dev/null
+++ b/drivers/counter/microchip-tcb-capture.c
@@ -0,0 +1,407 @@
+// 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/of_device.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);