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Commit 597f55e3 authored by Fabrice Gasnier's avatar Fabrice Gasnier Committed by Greg Kroah-Hartman
Browse files

counter: stm32-lptimer: add counter device 



Add support for new counter device to stm32-lptimer.

Signed-off-by: default avatarFabrice Gasnier <fabrice.gasnier@st.com>
Reviewed-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: default avatarWilliam Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent ec63e2a4

drivers/counter/Kconfig

+10 −0
Original line number Diff line number Diff line
@@ -38,4 +38,14 @@ config STM32_TIMER_CNT 
	  To compile this driver as a module, choose M here: the

	  module will be called stm32-timer-cnt.



config STM32_LPTIMER_CNT

	tristate "STM32 LP Timer encoder counter driver"

	depends on (MFD_STM32_LPTIMER || COMPILE_TEST) && IIO

	help

	  Select this option to enable STM32 Low-Power Timer quadrature encoder

	  and counter driver.



	  To compile this driver as a module, choose M here: the

	  module will be called stm32-lptimer-cnt.



endif # COUNTER

drivers/counter/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -6,3 +6,4 @@ obj-$(CONFIG_COUNTER) += counter.o 


obj-$(CONFIG_104_QUAD_8)	+= 104-quad-8.o

obj-$(CONFIG_STM32_TIMER_CNT)	+= stm32-timer-cnt.o

obj-$(CONFIG_STM32_LPTIMER_CNT)	+= stm32-lptimer-cnt.o

drivers/iio/counter/stm32-lptimer-cnt.c→drivers/counter/stm32-lptimer-cnt.c

+339 −22
Original line number Diff line number Diff line
@@ -11,6 +11,7 @@ 
 */



#include <linux/bitfield.h>

#include <linux/counter.h>

#include <linux/iio/iio.h>

#include <linux/mfd/stm32-lptimer.h>

#include <linux/module.h>
@@ -18,10 +19,11 @@ 
#include <linux/platform_device.h>



struct stm32_lptim_cnt {

	struct counter_device counter;

	struct device *dev;

	struct regmap *regmap;

	struct clk *clk;

	u32 preset;

	u32 ceiling;

	u32 polarity;

	u32 quadrature_mode;

	bool enabled;
@@ -57,7 +59,7 @@ static int stm32_lptim_set_enable_state(struct stm32_lptim_cnt *priv, 
	}



	/* LP timer must be enabled before writing CMP & ARR */

	ret = regmap_write(priv->regmap, STM32_LPTIM_ARR, priv->preset);

	ret = regmap_write(priv->regmap, STM32_LPTIM_ARR, priv->ceiling);

	if (ret)

		return ret;
@@ -251,44 +253,57 @@ static const struct iio_enum stm32_lptim_cnt_polarity_en = { 
	.set = stm32_lptim_cnt_set_polarity,

};



static ssize_t stm32_lptim_cnt_get_preset(struct iio_dev *indio_dev,

					  uintptr_t private,

					  const struct iio_chan_spec *chan,

static ssize_t stm32_lptim_cnt_get_ceiling(struct stm32_lptim_cnt *priv,

					   char *buf)

{

	struct stm32_lptim_cnt *priv = iio_priv(indio_dev);



	return snprintf(buf, PAGE_SIZE, "%u\n", priv->preset);

	return snprintf(buf, PAGE_SIZE, "%u\n", priv->ceiling);

}



static ssize_t stm32_lptim_cnt_set_preset(struct iio_dev *indio_dev,

					  uintptr_t private,

					  const struct iio_chan_spec *chan,

static ssize_t stm32_lptim_cnt_set_ceiling(struct stm32_lptim_cnt *priv,

					   const char *buf, size_t len)

{

	struct stm32_lptim_cnt *priv = iio_priv(indio_dev);

	int ret;



	if (stm32_lptim_is_enabled(priv))

		return -EBUSY;



	ret = kstrtouint(buf, 0, &priv->preset);

	ret = kstrtouint(buf, 0, &priv->ceiling);

	if (ret)

		return ret;



	if (priv->preset > STM32_LPTIM_MAX_ARR)

	if (priv->ceiling > STM32_LPTIM_MAX_ARR)

		return -EINVAL;



	return len;

}



static ssize_t stm32_lptim_cnt_get_preset_iio(struct iio_dev *indio_dev,

					      uintptr_t private,

					      const struct iio_chan_spec *chan,

					      char *buf)

{

	struct stm32_lptim_cnt *priv = iio_priv(indio_dev);



	return stm32_lptim_cnt_get_ceiling(priv, buf);

}



static ssize_t stm32_lptim_cnt_set_preset_iio(struct iio_dev *indio_dev,

					      uintptr_t private,

					      const struct iio_chan_spec *chan,

					      const char *buf, size_t len)

{

	struct stm32_lptim_cnt *priv = iio_priv(indio_dev);



	return stm32_lptim_cnt_set_ceiling(priv, buf, len);

}



/* LP timer with encoder */

static const struct iio_chan_spec_ext_info stm32_lptim_enc_ext_info[] = {

	{

		.name = "preset",

		.shared = IIO_SEPARATE,

		.read = stm32_lptim_cnt_get_preset,

		.write = stm32_lptim_cnt_set_preset,

		.read = stm32_lptim_cnt_get_preset_iio,

		.write = stm32_lptim_cnt_set_preset_iio,

	},

	IIO_ENUM("polarity", IIO_SEPARATE, &stm32_lptim_cnt_polarity_en),

	IIO_ENUM_AVAILABLE("polarity", &stm32_lptim_cnt_polarity_en),
@@ -313,8 +328,8 @@ static const struct iio_chan_spec_ext_info stm32_lptim_cnt_ext_info[] = { 
	{

		.name = "preset",

		.shared = IIO_SEPARATE,

		.read = stm32_lptim_cnt_get_preset,

		.write = stm32_lptim_cnt_set_preset,

		.read = stm32_lptim_cnt_get_preset_iio,

		.write = stm32_lptim_cnt_set_preset_iio,

	},

	IIO_ENUM("polarity", IIO_SEPARATE, &stm32_lptim_cnt_polarity_en),

	IIO_ENUM_AVAILABLE("polarity", &stm32_lptim_cnt_polarity_en),
@@ -331,11 +346,293 @@ static const struct iio_chan_spec stm32_lptim_cnt_channels = { 
	.indexed = 1,

};



/**

 * stm32_lptim_cnt_function - enumerates stm32 LPTimer counter & encoder modes

 * @STM32_LPTIM_COUNTER_INCREASE: up count on IN1 rising, falling or both edges

 * @STM32_LPTIM_ENCODER_BOTH_EDGE: count on both edges (IN1 & IN2 quadrature)

 */

enum stm32_lptim_cnt_function {

	STM32_LPTIM_COUNTER_INCREASE,

	STM32_LPTIM_ENCODER_BOTH_EDGE,

};



static enum counter_count_function stm32_lptim_cnt_functions[] = {

	[STM32_LPTIM_COUNTER_INCREASE] = COUNTER_COUNT_FUNCTION_INCREASE,

	[STM32_LPTIM_ENCODER_BOTH_EDGE] = COUNTER_COUNT_FUNCTION_QUADRATURE_X4,

};



enum stm32_lptim_synapse_action {

	STM32_LPTIM_SYNAPSE_ACTION_RISING_EDGE,

	STM32_LPTIM_SYNAPSE_ACTION_FALLING_EDGE,

	STM32_LPTIM_SYNAPSE_ACTION_BOTH_EDGES,

	STM32_LPTIM_SYNAPSE_ACTION_NONE,

};



static enum counter_synapse_action stm32_lptim_cnt_synapse_actions[] = {

	/* Index must match with stm32_lptim_cnt_polarity[] (priv->polarity) */

	[STM32_LPTIM_SYNAPSE_ACTION_RISING_EDGE] = COUNTER_SYNAPSE_ACTION_RISING_EDGE,

	[STM32_LPTIM_SYNAPSE_ACTION_FALLING_EDGE] = COUNTER_SYNAPSE_ACTION_FALLING_EDGE,

	[STM32_LPTIM_SYNAPSE_ACTION_BOTH_EDGES] = COUNTER_SYNAPSE_ACTION_BOTH_EDGES,

	[STM32_LPTIM_SYNAPSE_ACTION_NONE] = COUNTER_SYNAPSE_ACTION_NONE,

};



static int stm32_lptim_cnt_read(struct counter_device *counter,

				struct counter_count *count,

				struct counter_count_read_value *val)

{

	struct stm32_lptim_cnt *const priv = counter->priv;

	u32 cnt;

	int ret;



	ret = regmap_read(priv->regmap, STM32_LPTIM_CNT, &cnt);

	if (ret)

		return ret;



	counter_count_read_value_set(val, COUNTER_COUNT_POSITION, &cnt);



	return 0;

}



static int stm32_lptim_cnt_function_get(struct counter_device *counter,

					struct counter_count *count,

					size_t *function)

{

	struct stm32_lptim_cnt *const priv = counter->priv;



	if (!priv->quadrature_mode) {

		*function = STM32_LPTIM_COUNTER_INCREASE;

		return 0;

	}



	if (priv->polarity == STM32_LPTIM_SYNAPSE_ACTION_BOTH_EDGES) {

		*function = STM32_LPTIM_ENCODER_BOTH_EDGE;

		return 0;

	}



	return -EINVAL;

}



static int stm32_lptim_cnt_function_set(struct counter_device *counter,

					struct counter_count *count,

					size_t function)

{

	struct stm32_lptim_cnt *const priv = counter->priv;



	if (stm32_lptim_is_enabled(priv))

		return -EBUSY;



	switch (function) {

	case STM32_LPTIM_COUNTER_INCREASE:

		priv->quadrature_mode = 0;

		return 0;

	case STM32_LPTIM_ENCODER_BOTH_EDGE:

		priv->quadrature_mode = 1;

		priv->polarity = STM32_LPTIM_SYNAPSE_ACTION_BOTH_EDGES;

		return 0;

	}



	return -EINVAL;

}



static ssize_t stm32_lptim_cnt_enable_read(struct counter_device *counter,

					   struct counter_count *count,

					   void *private, char *buf)

{

	struct stm32_lptim_cnt *const priv = counter->priv;

	int ret;



	ret = stm32_lptim_is_enabled(priv);

	if (ret < 0)

		return ret;



	return scnprintf(buf, PAGE_SIZE, "%u\n", ret);

}



static ssize_t stm32_lptim_cnt_enable_write(struct counter_device *counter,

					    struct counter_count *count,

					    void *private,

					    const char *buf, size_t len)

{

	struct stm32_lptim_cnt *const priv = counter->priv;

	bool enable;

	int ret;



	ret = kstrtobool(buf, &enable);

	if (ret)

		return 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 len;

}



static ssize_t stm32_lptim_cnt_ceiling_read(struct counter_device *counter,

					    struct counter_count *count,

					    void *private, char *buf)

{

	struct stm32_lptim_cnt *const priv = counter->priv;



	return stm32_lptim_cnt_get_ceiling(priv, buf);

}



static ssize_t stm32_lptim_cnt_ceiling_write(struct counter_device *counter,

					     struct counter_count *count,

					     void *private,

					     const char *buf, size_t len)

{

	struct stm32_lptim_cnt *const priv = counter->priv;



	return stm32_lptim_cnt_set_ceiling(priv, buf, len);

}



static const struct counter_count_ext stm32_lptim_cnt_ext[] = {

	{

		.name = "enable",

		.read = stm32_lptim_cnt_enable_read,

		.write = stm32_lptim_cnt_enable_write

	},

	{

		.name = "ceiling",

		.read = stm32_lptim_cnt_ceiling_read,

		.write = stm32_lptim_cnt_ceiling_write

	},

};



static int stm32_lptim_cnt_action_get(struct counter_device *counter,

				      struct counter_count *count,

				      struct counter_synapse *synapse,

				      size_t *action)

{

	struct stm32_lptim_cnt *const priv = counter->priv;

	size_t function;

	int err;



	err = stm32_lptim_cnt_function_get(counter, count, &function);

	if (err)

		return err;



	switch (function) {

	case STM32_LPTIM_COUNTER_INCREASE:

		/* LP Timer acts as up-counter on input 1 */

		if (synapse->signal->id == count->synapses[0].signal->id)

			*action = priv->polarity;

		else

			*action = STM32_LPTIM_SYNAPSE_ACTION_NONE;

		return 0;

	case STM32_LPTIM_ENCODER_BOTH_EDGE:

		*action = priv->polarity;

		return 0;

	}



	return -EINVAL;

}



static int stm32_lptim_cnt_action_set(struct counter_device *counter,

				      struct counter_count *count,

				      struct counter_synapse *synapse,

				      size_t action)

{

	struct stm32_lptim_cnt *const priv = counter->priv;

	size_t function;

	int err;



	if (stm32_lptim_is_enabled(priv))

		return -EBUSY;



	err = stm32_lptim_cnt_function_get(counter, count, &function);

	if (err)

		return err;



	/* only set polarity when in counter mode (on input 1) */

	if (function == STM32_LPTIM_COUNTER_INCREASE

	    && synapse->signal->id == count->synapses[0].signal->id) {

		switch (action) {

		case STM32_LPTIM_SYNAPSE_ACTION_RISING_EDGE:

		case STM32_LPTIM_SYNAPSE_ACTION_FALLING_EDGE:

		case STM32_LPTIM_SYNAPSE_ACTION_BOTH_EDGES:

			priv->polarity = action;

			return 0;

		}

	}



	return -EINVAL;

}



static const struct counter_ops stm32_lptim_cnt_ops = {

	.count_read = stm32_lptim_cnt_read,

	.function_get = stm32_lptim_cnt_function_get,

	.function_set = stm32_lptim_cnt_function_set,

	.action_get = stm32_lptim_cnt_action_get,

	.action_set = stm32_lptim_cnt_action_set,

};



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 stm32_lptim_cnt *priv;

	struct iio_dev *indio_dev;

	int ret;



	if (IS_ERR_OR_NULL(ddata))

		return -EINVAL;
@@ -348,8 +645,9 @@ static int stm32_lptim_cnt_probe(struct platform_device *pdev) 
	priv->dev = &pdev->dev;

	priv->regmap = ddata->regmap;

	priv->clk = ddata->clk;

	priv->preset = STM32_LPTIM_MAX_ARR;

	priv->ceiling = STM32_LPTIM_MAX_ARR;



	/* Initialize IIO device */

	indio_dev->name = dev_name(&pdev->dev);

	indio_dev->dev.parent = &pdev->dev;

	indio_dev->dev.of_node = pdev->dev.of_node;
@@ -360,9 +658,28 @@ static int stm32_lptim_cnt_probe(struct platform_device *pdev) 
		indio_dev->channels = &stm32_lptim_cnt_channels;

	indio_dev->num_channels = 1;



	/* Initialize Counter device */

	priv->counter.name = dev_name(&pdev->dev);

	priv->counter.parent = &pdev->dev;

	priv->counter.ops = &stm32_lptim_cnt_ops;

	if (ddata->has_encoder) {

		priv->counter.counts = &stm32_lptim_enc_counts;

		priv->counter.num_signals = ARRAY_SIZE(stm32_lptim_cnt_signals);

	} else {

		priv->counter.counts = &stm32_lptim_in1_counts;

		priv->counter.num_signals = 1;

	}

	priv->counter.num_counts = 1;

	priv->counter.signals = stm32_lptim_cnt_signals;

	priv->counter.priv = priv;



	platform_set_drvdata(pdev, priv);



	return devm_iio_device_register(&pdev->dev, indio_dev);

	ret = devm_iio_device_register(&pdev->dev, indio_dev);

	if (ret)

		return ret;



	return devm_counter_register(&pdev->dev, &priv->counter);

}



#ifdef CONFIG_PM_SLEEP

drivers/iio/Kconfig

+0 −1
Original line number Diff line number Diff line
@@ -74,7 +74,6 @@ source "drivers/iio/afe/Kconfig" 
source "drivers/iio/amplifiers/Kconfig"

source "drivers/iio/chemical/Kconfig"

source "drivers/iio/common/Kconfig"

source "drivers/iio/counter/Kconfig"

source "drivers/iio/dac/Kconfig"

source "drivers/iio/dummy/Kconfig"

source "drivers/iio/frequency/Kconfig"

drivers/iio/Makefile

+0 −1
Original line number Diff line number Diff line
@@ -20,7 +20,6 @@ obj-y += amplifiers/ 
obj-y += buffer/

obj-y += chemical/

obj-y += common/

obj-y += counter/

obj-y += dac/

obj-y += dummy/

obj-y += gyro/