counter: stm32-lptimer: add counter device

Add support for new counter device to stm32-lptimer.

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Fabrice Gasnier 2019-04-02 15:30:44 +09:00 committed by Greg Kroah-Hartman
parent ec63e2a489
commit 597f55e3f3
7 changed files with 350 additions and 48 deletions

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@ -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

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@ -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

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@ -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,
char *buf)
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,
const char *buf, size_t len)
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

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@ -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"

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@ -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/

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@ -1,17 +0,0 @@
#
# Counter devices
#
# When adding new entries keep the list in alphabetical order
menu "Counters"
config STM32_LPTIMER_CNT
tristate "STM32 LP Timer encoder counter driver"
depends on MFD_STM32_LPTIMER || COMPILE_TEST
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.
endmenu

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@ -1,7 +0,0 @@
#
# Makefile for IIO counter devices
#
# When adding new entries keep the list in alphabetical order
obj-$(CONFIG_STM32_LPTIMER_CNT) += stm32-lptimer-cnt.o