Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 523 insertions, 0 deletions

diff --git a/drivers/counter/stm32-lptimer-cnt.c b/drivers/counter/stm32-lptimer-cnt.c
new file mode 100644
index 000000000..843975555
--- /dev/null
+++ b/drivers/counter/stm32-lptimer-cnt.c
@@ -0,0 +1,523 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * STM32 Low-Power Timer Encoder and Counter driver
+ *
+ * Copyright (C) STMicroelectronics 2017
+ *
+ * Author: Fabrice Gasnier <fabrice.gasnier@st.com>
+ *
+ * Inspired by 104-quad-8 and stm32-timer-trigger drivers.
+ *
+ */
+
+#include <linux/bitfield.h>
+#include <linux/counter.h>
+#include <linux/mfd/stm32-lptimer.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/pinctrl/consumer.h>
+#include <linux/platform_device.h>
+#include <linux/types.h>
+
+struct stm32_lptim_cnt {
+	struct device *dev;
+	struct regmap *regmap;
+	struct clk *clk;
+	u32 ceiling;
+	u32 polarity;
+	u32 quadrature_mode;
+	bool enabled;
+};
+
+static int stm32_lptim_is_enabled(struct stm32_lptim_cnt *priv)
+{
+	u32 val;
+	int ret;
+
+	ret = regmap_read(priv->regmap, STM32_LPTIM_CR, &val);
+	if (ret)
+		return ret;
+
+	return FIELD_GET(STM32_LPTIM_ENABLE, val);
+}
+
+static int stm32_lptim_set_enable_state(struct stm32_lptim_cnt *priv,
+					int enable)
+{
+	int ret;
+	u32 val;
+
+	val = FIELD_PREP(STM32_LPTIM_ENABLE, enable);
+	ret = regmap_write(priv->regmap, STM32_LPTIM_CR, val);
+	if (ret)
+		return ret;
+
+	if (!enable) {
+		clk_disable(priv->clk);
+		priv->enabled = false;
+		return 0;
+	}
+
+	/* LP timer must be enabled before writing CMP & ARR */
+	ret = regmap_write(priv->regmap, STM32_LPTIM_ARR, priv->ceiling);
+	if (ret)
+		return ret;
+
+	ret = regmap_write(priv->regmap, STM32_LPTIM_CMP, 0);
+	if (ret)
+		return ret;
+
+	/* ensure CMP & ARR registers are properly written */
+	ret = regmap_read_poll_timeout(priv->regmap, STM32_LPTIM_ISR, val,
+				       (val & STM32_LPTIM_CMPOK_ARROK) == STM32_LPTIM_CMPOK_ARROK,
+				       100, 1000);
+	if (ret)
+		return ret;
+
+	ret = regmap_write(priv->regmap, STM32_LPTIM_ICR,
+			   STM32_LPTIM_CMPOKCF_ARROKCF);
+	if (ret)
+		return ret;
+
+	ret = clk_enable(priv->clk);
+	if (ret) {
+		regmap_write(priv->regmap, STM32_LPTIM_CR, 0);
+		return ret;
+	}
+	priv->enabled = true;
+
+	/* Start LP timer in continuous mode */
+	return regmap_update_bits(priv->regmap, STM32_LPTIM_CR,
+				  STM32_LPTIM_CNTSTRT, STM32_LPTIM_CNTSTRT);
+}
+
+static int stm32_lptim_setup(struct stm32_lptim_cnt *priv, int enable)
+{
+	u32 mask = STM32_LPTIM_ENC | STM32_LPTIM_COUNTMODE |
+		   STM32_LPTIM_CKPOL | STM32_LPTIM_PRESC;
+	u32 val;
+
+	/* Setup LP timer encoder/counter and polarity, without prescaler */
+	if (priv->quadrature_mode)
+		val = enable ? STM32_LPTIM_ENC : 0;
+	else
+		val = enable ? STM32_LPTIM_COUNTMODE : 0;
+	val |= FIELD_PREP(STM32_LPTIM_CKPOL, enable ? priv->polarity : 0);
+
+	return regmap_update_bits(priv->regmap, STM32_LPTIM_CFGR, mask, val);
+}
+
+/*
+ * In non-quadrature mode, device counts up on active edge.
+ * In quadrature mode, encoder counting scenarios are as follows:
+ * +---------+----------+--------------------+--------------------+
+ * | Active  | Level on |      IN1 signal    |     IN2 signal     |
+ * | edge    | opposite +----------+---------+----------+---------+
+ * |         | signal   |  Rising  | Falling |  Rising  | Falling |
+ * +---------+----------+----------+---------+----------+---------+
+ * | Rising  | High ->  |   Down   |    -    |   Up     |    -    |
+ * | edge    | Low  ->  |   Up     |    -    |   Down   |    -    |
+ * +---------+----------+----------+---------+----------+---------+
+ * | Falling | High ->  |    -     |   Up    |    -     |   Down  |
+ * | edge    | Low  ->  |    -     |   Down  |    -     |   Up    |
+ * +---------+----------+----------+---------+----------+---------+
+ * | Both    | High ->  |   Down   |   Up    |   Up     |   Down  |
+ * | edges   | Low  ->  |   Up     |   Down  |   Down   |   Up    |
+ * +---------+----------+----------+---------+----------+---------+
+ */
+static const enum counter_function stm32_lptim_cnt_functions[] = {
+	COUNTER_FUNCTION_INCREASE,
+	COUNTER_FUNCTION_QUADRATURE_X4,
+};
+
+static const enum counter_synapse_action stm32_lptim_cnt_synapse_actions[] = {
+	COUNTER_SYNAPSE_ACTION_RISING_EDGE,
+	COUNTER_SYNAPSE_ACTION_FALLING_EDGE,
+	COUNTER_SYNAPSE_ACTION_BOTH_EDGES,
+	COUNTER_SYNAPSE_ACTION_NONE,
+};
+
+static int stm32_lptim_cnt_read(struct counter_device *counter,
+				struct counter_count *count, u64 *val)
+{
+	struct stm32_lptim_cnt *const priv = counter_priv(counter);
+	u32 cnt;
+	int ret;
+
+	ret = regmap_read(priv->regmap, STM32_LPTIM_CNT, &cnt);
+	if (ret)
+		return ret;
+
+	*val = cnt;
+
+	return 0;
+}
+
+static int stm32_lptim_cnt_function_read(struct counter_device *counter,
+					 struct counter_count *count,
+					 enum counter_function *function)
+{
+	struct stm32_lptim_cnt *const priv = counter_priv(counter);
+
+	if (!priv->quadrature_mode) {
+		*function = COUNTER_FUNCTION_INCREASE;
+		return 0;
+	}
+
+	if (priv->polarity == STM32_LPTIM_CKPOL_BOTH_EDGES) {
+		*function = COUNTER_FUNCTION_QUADRATURE_X4;
+		return 0;
+	}
+
+	return -EINVAL;
+}
+
+static int stm32_lptim_cnt_function_write(struct counter_device *counter,
+					  struct counter_count *count,
+					  enum counter_function function)
+{
+	struct stm32_lptim_cnt *const priv = counter_priv(counter);
+
+	if (stm32_lptim_is_enabled(priv))
+		return -EBUSY;
+
+	switch (function) {
+	case COUNTER_FUNCTION_INCREASE:
+		priv->quadrature_mode = 0;
+		return 0;
+	case COUNTER_FUNCTION_QUADRATURE_X4:
+		priv->quadrature_mode = 1;
+		priv->polarity = STM32_LPTIM_CKPOL_BOTH_EDGES;
+		return 0;
+	default:
+		/* should never reach this path */
+		return -EINVAL;
+	}
+}
+
+static int stm32_lptim_cnt_enable_read(struct counter_device *counter,
+				       struct counter_count *count,
+				       u8 *enable)
+{
+	struct stm32_lptim_cnt *const priv = counter_priv(counter);
+	int ret;
+
+	ret = stm32_lptim_is_enabled(priv);
+	if (ret < 0)
+		return ret;
+
+	*enable = ret;
+
+	return 0;
+}
+
+static int stm32_lptim_cnt_enable_write(struct counter_device *counter,
+					struct counter_count *count,
+					u8 enable)
+{
+	struct stm32_lptim_cnt *const priv = counter_priv(counter);
+	int ret;
+
+	/* Check nobody uses the timer, or already disabled/enabled */
+	ret = stm32_lptim_is_enabled(priv);
+	if ((ret < 0) || (!ret && !enable))
+		return ret;
+	if (enable && ret)
+		return -EBUSY;
+
+	ret = stm32_lptim_setup(priv, enable);
+	if (ret)
+		return ret;
+
+	ret = stm32_lptim_set_enable_state(priv, enable);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static int stm32_lptim_cnt_ceiling_read(struct counter_device *counter,
+					struct counter_count *count,
+					u64 *ceiling)
+{
+	struct stm32_lptim_cnt *const priv = counter_priv(counter);
+
+	*ceiling = priv->ceiling;
+
+	return 0;
+}
+
+static int stm32_lptim_cnt_ceiling_write(struct counter_device *counter,
+					 struct counter_count *count,
+					 u64 ceiling)
+{
+	struct stm32_lptim_cnt *const priv = counter_priv(counter);
+
+	if (stm32_lptim_is_enabled(priv))
+		return -EBUSY;
+
+	if (ceiling > STM32_LPTIM_MAX_ARR)
+		return -ERANGE;
+
+	priv->ceiling = ceiling;
+
+	return 0;
+}
+
+static struct counter_comp stm32_lptim_cnt_ext[] = {
+	COUNTER_COMP_ENABLE(stm32_lptim_cnt_enable_read,
+			    stm32_lptim_cnt_enable_write),
+	COUNTER_COMP_CEILING(stm32_lptim_cnt_ceiling_read,
+			     stm32_lptim_cnt_ceiling_write),
+};
+
+static int stm32_lptim_cnt_action_read(struct counter_device *counter,
+				       struct counter_count *count,
+				       struct counter_synapse *synapse,
+				       enum counter_synapse_action *action)
+{
+	struct stm32_lptim_cnt *const priv = counter_priv(counter);
+	enum counter_function function;
+	int err;
+
+	err = stm32_lptim_cnt_function_read(counter, count, &function);
+	if (err)
+		return err;
+
+	switch (function) {
+	case COUNTER_FUNCTION_INCREASE:
+		/* LP Timer acts as up-counter on input 1 */
+		if (synapse->signal->id != count->synapses[0].signal->id) {
+			*action = COUNTER_SYNAPSE_ACTION_NONE;
+			return 0;
+		}
+
+		switch (priv->polarity) {
+		case STM32_LPTIM_CKPOL_RISING_EDGE:
+			*action = COUNTER_SYNAPSE_ACTION_RISING_EDGE;
+			return 0;
+		case STM32_LPTIM_CKPOL_FALLING_EDGE:
+			*action = COUNTER_SYNAPSE_ACTION_FALLING_EDGE;
+			return 0;
+		case STM32_LPTIM_CKPOL_BOTH_EDGES:
+			*action = COUNTER_SYNAPSE_ACTION_BOTH_EDGES;
+			return 0;
+		default:
+			/* should never reach this path */
+			return -EINVAL;
+		}
+	case COUNTER_FUNCTION_QUADRATURE_X4:
+		*action = COUNTER_SYNAPSE_ACTION_BOTH_EDGES;
+		return 0;
+	default:
+		/* should never reach this path */
+		return -EINVAL;
+	}
+}
+
+static int stm32_lptim_cnt_action_write(struct counter_device *counter,
+					struct counter_count *count,
+					struct counter_synapse *synapse,
+					enum counter_synapse_action action)
+{
+	struct stm32_lptim_cnt *const priv = counter_priv(counter);
+	enum counter_function function;
+	int err;
+
+	if (stm32_lptim_is_enabled(priv))
+		return -EBUSY;
+
+	err = stm32_lptim_cnt_function_read(counter, count, &function);
+	if (err)
+		return err;
+
+	/* only set polarity when in counter mode (on input 1) */
+	if (function != COUNTER_FUNCTION_INCREASE
+	    || synapse->signal->id != count->synapses[0].signal->id)
+		return -EINVAL;
+
+	switch (action) {
+	case COUNTER_SYNAPSE_ACTION_RISING_EDGE:
+		priv->polarity = STM32_LPTIM_CKPOL_RISING_EDGE;
+		return 0;
+	case COUNTER_SYNAPSE_ACTION_FALLING_EDGE:
+		priv->polarity = STM32_LPTIM_CKPOL_FALLING_EDGE;
+		return 0;
+	case COUNTER_SYNAPSE_ACTION_BOTH_EDGES:
+		priv->polarity = STM32_LPTIM_CKPOL_BOTH_EDGES;
+		return 0;
+	default:
+		return -EINVAL;
+	}
+}
+
+static const struct counter_ops stm32_lptim_cnt_ops = {
+	.count_read = stm32_lptim_cnt_read,
+	.function_read = stm32_lptim_cnt_function_read,
+	.function_write = stm32_lptim_cnt_function_write,
+	.action_read = stm32_lptim_cnt_action_read,
+	.action_write = stm32_lptim_cnt_action_write,
+};
+
+static struct counter_signal stm32_lptim_cnt_signals[] = {
+	{
+		.id = 0,
+		.name = "Channel 1 Quadrature A"
+	},
+	{
+		.id = 1,
+		.name = "Channel 1 Quadrature B"
+	}
+};
+
+static struct counter_synapse stm32_lptim_cnt_synapses[] = {
+	{
+		.actions_list = stm32_lptim_cnt_synapse_actions,
+		.num_actions = ARRAY_SIZE(stm32_lptim_cnt_synapse_actions),
+		.signal = &stm32_lptim_cnt_signals[0]
+	},
+	{
+		.actions_list = stm32_lptim_cnt_synapse_actions,
+		.num_actions = ARRAY_SIZE(stm32_lptim_cnt_synapse_actions),
+		.signal = &stm32_lptim_cnt_signals[1]
+	}
+};
+
+/* LP timer with encoder */
+static struct counter_count stm32_lptim_enc_counts = {
+	.id = 0,
+	.name = "LPTimer Count",
+	.functions_list = stm32_lptim_cnt_functions,
+	.num_functions = ARRAY_SIZE(stm32_lptim_cnt_functions),
+	.synapses = stm32_lptim_cnt_synapses,
+	.num_synapses = ARRAY_SIZE(stm32_lptim_cnt_synapses),
+	.ext = stm32_lptim_cnt_ext,
+	.num_ext = ARRAY_SIZE(stm32_lptim_cnt_ext)
+};
+
+/* LP timer without encoder (counter only) */
+static struct counter_count stm32_lptim_in1_counts = {
+	.id = 0,
+	.name = "LPTimer Count",
+	.functions_list = stm32_lptim_cnt_functions,
+	.num_functions = 1,
+	.synapses = stm32_lptim_cnt_synapses,
+	.num_synapses = 1,
+	.ext = stm32_lptim_cnt_ext,
+	.num_ext = ARRAY_SIZE(stm32_lptim_cnt_ext)
+};
+
+static int stm32_lptim_cnt_probe(struct platform_device *pdev)
+{
+	struct stm32_lptimer *ddata = dev_get_drvdata(pdev->dev.parent);
+	struct counter_device *counter;
+	struct stm32_lptim_cnt *priv;
+	int ret;
+
+	if (IS_ERR_OR_NULL(ddata))
+		return -EINVAL;
+
+	counter = devm_counter_alloc(&pdev->dev, sizeof(*priv));
+	if (!counter)
+		return -ENOMEM;
+	priv = counter_priv(counter);
+
+	priv->dev = &pdev->dev;
+	priv->regmap = ddata->regmap;
+	priv->clk = ddata->clk;
+	priv->ceiling = STM32_LPTIM_MAX_ARR;
+
+	/* Initialize Counter device */
+	counter->name = dev_name(&pdev->dev);
+	counter->parent = &pdev->dev;
+	counter->ops = &stm32_lptim_cnt_ops;
+	if (ddata->has_encoder) {
+		counter->counts = &stm32_lptim_enc_counts;
+		counter->num_signals = ARRAY_SIZE(stm32_lptim_cnt_signals);
+	} else {
+		counter->counts = &stm32_lptim_in1_counts;
+		counter->num_signals = 1;
+	}
+	counter->num_counts = 1;
+	counter->signals = stm32_lptim_cnt_signals;
+
+	platform_set_drvdata(pdev, priv);
+
+	ret = devm_counter_add(&pdev->dev, counter);
+	if (ret < 0)
+		return dev_err_probe(&pdev->dev, ret, "Failed to add counter\n");
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int stm32_lptim_cnt_suspend(struct device *dev)
+{
+	struct stm32_lptim_cnt *priv = dev_get_drvdata(dev);
+	int ret;
+
+	/* Only take care of enabled counter: don't disturb other MFD child */
+	if (priv->enabled) {
+		ret = stm32_lptim_setup(priv, 0);
+		if (ret)
+			return ret;
+
+		ret = stm32_lptim_set_enable_state(priv, 0);
+		if (ret)
+			return ret;
+
+		/* Force enable state for later resume */
+		priv->enabled = true;
+	}
+
+	return pinctrl_pm_select_sleep_state(dev);
+}
+
+static int stm32_lptim_cnt_resume(struct device *dev)
+{
+	struct stm32_lptim_cnt *priv = dev_get_drvdata(dev);
+	int ret;
+
+	ret = pinctrl_pm_select_default_state(dev);
+	if (ret)
+		return ret;
+
+	if (priv->enabled) {
+		priv->enabled = false;
+		ret = stm32_lptim_setup(priv, 1);
+		if (ret)
+			return ret;
+
+		ret = stm32_lptim_set_enable_state(priv, 1);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(stm32_lptim_cnt_pm_ops, stm32_lptim_cnt_suspend,
+			 stm32_lptim_cnt_resume);
+
+static const struct of_device_id stm32_lptim_cnt_of_match[] = {
+	{ .compatible = "st,stm32-lptimer-counter", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, stm32_lptim_cnt_of_match);
+
+static struct platform_driver stm32_lptim_cnt_driver = {
+	.probe = stm32_lptim_cnt_probe,
+	.driver = {
+		.name = "stm32-lptimer-counter",
+		.of_match_table = stm32_lptim_cnt_of_match,
+		.pm = &stm32_lptim_cnt_pm_ops,
+	},
+};
+module_platform_driver(stm32_lptim_cnt_driver);
+
+MODULE_AUTHOR("Fabrice Gasnier <fabrice.gasnier@st.com>");
+MODULE_ALIAS("platform:stm32-lptimer-counter");
+MODULE_DESCRIPTION("STMicroelectronics STM32 LPTIM counter driver");
+MODULE_LICENSE("GPL v2");
+MODULE_IMPORT_NS(COUNTER);