--- /dev/null
+// 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/iio/iio.h>
+#include <linux/mfd/stm32-lptimer.h>
+#include <linux/module.h>
+#include <linux/pinctrl/consumer.h>
+#include <linux/platform_device.h>
+
+struct stm32_lptim_cnt {
+ struct counter_device counter;
+ 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),
+ 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);
+}
+
+static int stm32_lptim_write_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int val, int val2, long mask)
+{
+ struct stm32_lptim_cnt *priv = iio_priv(indio_dev);
+ int ret;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_ENABLE:
+ if (val < 0 || val > 1)
+ return -EINVAL;
+
+ /* Check nobody uses the timer, or already disabled/enabled */
+ ret = stm32_lptim_is_enabled(priv);
+ if ((ret < 0) || (!ret && !val))
+ return ret;
+ if (val && ret)
+ return -EBUSY;
+
+ ret = stm32_lptim_setup(priv, val);
+ if (ret)
+ return ret;
+ return stm32_lptim_set_enable_state(priv, val);
+
+ default:
+ return -EINVAL;
+ }
+}
+
+static int stm32_lptim_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val, int *val2, long mask)
+{
+ struct stm32_lptim_cnt *priv = iio_priv(indio_dev);
+ u32 dat;
+ int ret;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ ret = regmap_read(priv->regmap, STM32_LPTIM_CNT, &dat);
+ if (ret)
+ return ret;
+ *val = dat;
+ return IIO_VAL_INT;
+
+ case IIO_CHAN_INFO_ENABLE:
+ ret = stm32_lptim_is_enabled(priv);
+ if (ret < 0)
+ return ret;
+ *val = ret;
+ return IIO_VAL_INT;
+
+ case IIO_CHAN_INFO_SCALE:
+ /* Non-quadrature mode: scale = 1 */
+ *val = 1;
+ *val2 = 0;
+ if (priv->quadrature_mode) {
+ /*
+ * Quadrature encoder mode:
+ * - both edges, quarter cycle, scale is 0.25
+ * - either rising/falling edge scale is 0.5
+ */
+ if (priv->polarity > 1)
+ *val2 = 2;
+ else
+ *val2 = 1;
+ }
+ return IIO_VAL_FRACTIONAL_LOG2;
+
+ default:
+ return -EINVAL;
+ }
+}
+
+static const struct iio_info stm32_lptim_cnt_iio_info = {
+ .read_raw = stm32_lptim_read_raw,
+ .write_raw = stm32_lptim_write_raw,
+};
+
+static const char *const stm32_lptim_quadrature_modes[] = {
+ "non-quadrature",
+ "quadrature",
+};
+
+static int stm32_lptim_get_quadrature_mode(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan)
+{
+ struct stm32_lptim_cnt *priv = iio_priv(indio_dev);
+
+ return priv->quadrature_mode;
+}
+
+static int stm32_lptim_set_quadrature_mode(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan,
+ unsigned int type)
+{
+ struct stm32_lptim_cnt *priv = iio_priv(indio_dev);
+
+ if (stm32_lptim_is_enabled(priv))
+ return -EBUSY;
+
+ priv->quadrature_mode = type;
+
+ return 0;
+}
+
+static const struct iio_enum stm32_lptim_quadrature_mode_en = {
+ .items = stm32_lptim_quadrature_modes,
+ .num_items = ARRAY_SIZE(stm32_lptim_quadrature_modes),
+ .get = stm32_lptim_get_quadrature_mode,
+ .set = stm32_lptim_set_quadrature_mode,
+};
+
+static const char * const stm32_lptim_cnt_polarity[] = {
+ "rising-edge", "falling-edge", "both-edges",
+};
+
+static int stm32_lptim_cnt_get_polarity(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan)
+{
+ struct stm32_lptim_cnt *priv = iio_priv(indio_dev);
+
+ return priv->polarity;
+}
+
+static int stm32_lptim_cnt_set_polarity(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan,
+ unsigned int type)
+{
+ struct stm32_lptim_cnt *priv = iio_priv(indio_dev);
+
+ if (stm32_lptim_is_enabled(priv))
+ return -EBUSY;
+
+ priv->polarity = type;
+
+ return 0;
+}
+
+static const struct iio_enum stm32_lptim_cnt_polarity_en = {
+ .items = stm32_lptim_cnt_polarity,
+ .num_items = ARRAY_SIZE(stm32_lptim_cnt_polarity),
+ .get = stm32_lptim_cnt_get_polarity,
+ .set = stm32_lptim_cnt_set_polarity,
+};
+
+static ssize_t stm32_lptim_cnt_get_ceiling(struct stm32_lptim_cnt *priv,
+ char *buf)
+{
+ return snprintf(buf, PAGE_SIZE, "%u\n", priv->ceiling);
+}
+
+static ssize_t stm32_lptim_cnt_set_ceiling(struct stm32_lptim_cnt *priv,
+ const char *buf, size_t len)
+{
+ int ret;
+
+ if (stm32_lptim_is_enabled(priv))
+ return -EBUSY;
+
+ ret = kstrtouint(buf, 0, &priv->ceiling);
+ if (ret)
+ return ret;
+
+ 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_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),
+ IIO_ENUM("quadrature_mode", IIO_SEPARATE,
+ &stm32_lptim_quadrature_mode_en),
+ IIO_ENUM_AVAILABLE("quadrature_mode", &stm32_lptim_quadrature_mode_en),
+ {}
+};
+
+static const struct iio_chan_spec stm32_lptim_enc_channels = {
+ .type = IIO_COUNT,
+ .channel = 0,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+ BIT(IIO_CHAN_INFO_ENABLE) |
+ BIT(IIO_CHAN_INFO_SCALE),
+ .ext_info = stm32_lptim_enc_ext_info,
+ .indexed = 1,
+};
+
+/* LP timer without encoder (counter only) */
+static const struct iio_chan_spec_ext_info stm32_lptim_cnt_ext_info[] = {
+ {
+ .name = "preset",
+ .shared = IIO_SEPARATE,
+ .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),
+ {}
+};
+
+static const struct iio_chan_spec stm32_lptim_cnt_channels = {
+ .type = IIO_COUNT,
+ .channel = 0,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+ BIT(IIO_CHAN_INFO_ENABLE) |
+ BIT(IIO_CHAN_INFO_SCALE),
+ .ext_info = stm32_lptim_cnt_ext_info,
+ .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;
+
+ indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*priv));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ priv = iio_priv(indio_dev);
+ priv->dev = &pdev->dev;
+ priv->regmap = ddata->regmap;
+ priv->clk = ddata->clk;
+ 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;
+ indio_dev->info = &stm32_lptim_cnt_iio_info;
+ if (ddata->has_encoder)
+ indio_dev->channels = &stm32_lptim_enc_channels;
+ else
+ 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);
+
+ 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
+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");
+++ /dev/null
-// 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/iio/iio.h>
-#include <linux/mfd/stm32-lptimer.h>
-#include <linux/module.h>
-#include <linux/pinctrl/consumer.h>
-#include <linux/platform_device.h>
-
-struct stm32_lptim_cnt {
- struct device *dev;
- struct regmap *regmap;
- struct clk *clk;
- u32 preset;
- 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->preset);
- 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),
- 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);
-}
-
-static int stm32_lptim_write_raw(struct iio_dev *indio_dev,
- struct iio_chan_spec const *chan,
- int val, int val2, long mask)
-{
- struct stm32_lptim_cnt *priv = iio_priv(indio_dev);
- int ret;
-
- switch (mask) {
- case IIO_CHAN_INFO_ENABLE:
- if (val < 0 || val > 1)
- return -EINVAL;
-
- /* Check nobody uses the timer, or already disabled/enabled */
- ret = stm32_lptim_is_enabled(priv);
- if ((ret < 0) || (!ret && !val))
- return ret;
- if (val && ret)
- return -EBUSY;
-
- ret = stm32_lptim_setup(priv, val);
- if (ret)
- return ret;
- return stm32_lptim_set_enable_state(priv, val);
-
- default:
- return -EINVAL;
- }
-}
-
-static int stm32_lptim_read_raw(struct iio_dev *indio_dev,
- struct iio_chan_spec const *chan,
- int *val, int *val2, long mask)
-{
- struct stm32_lptim_cnt *priv = iio_priv(indio_dev);
- u32 dat;
- int ret;
-
- switch (mask) {
- case IIO_CHAN_INFO_RAW:
- ret = regmap_read(priv->regmap, STM32_LPTIM_CNT, &dat);
- if (ret)
- return ret;
- *val = dat;
- return IIO_VAL_INT;
-
- case IIO_CHAN_INFO_ENABLE:
- ret = stm32_lptim_is_enabled(priv);
- if (ret < 0)
- return ret;
- *val = ret;
- return IIO_VAL_INT;
-
- case IIO_CHAN_INFO_SCALE:
- /* Non-quadrature mode: scale = 1 */
- *val = 1;
- *val2 = 0;
- if (priv->quadrature_mode) {
- /*
- * Quadrature encoder mode:
- * - both edges, quarter cycle, scale is 0.25
- * - either rising/falling edge scale is 0.5
- */
- if (priv->polarity > 1)
- *val2 = 2;
- else
- *val2 = 1;
- }
- return IIO_VAL_FRACTIONAL_LOG2;
-
- default:
- return -EINVAL;
- }
-}
-
-static const struct iio_info stm32_lptim_cnt_iio_info = {
- .read_raw = stm32_lptim_read_raw,
- .write_raw = stm32_lptim_write_raw,
-};
-
-static const char *const stm32_lptim_quadrature_modes[] = {
- "non-quadrature",
- "quadrature",
-};
-
-static int stm32_lptim_get_quadrature_mode(struct iio_dev *indio_dev,
- const struct iio_chan_spec *chan)
-{
- struct stm32_lptim_cnt *priv = iio_priv(indio_dev);
-
- return priv->quadrature_mode;
-}
-
-static int stm32_lptim_set_quadrature_mode(struct iio_dev *indio_dev,
- const struct iio_chan_spec *chan,
- unsigned int type)
-{
- struct stm32_lptim_cnt *priv = iio_priv(indio_dev);
-
- if (stm32_lptim_is_enabled(priv))
- return -EBUSY;
-
- priv->quadrature_mode = type;
-
- return 0;
-}
-
-static const struct iio_enum stm32_lptim_quadrature_mode_en = {
- .items = stm32_lptim_quadrature_modes,
- .num_items = ARRAY_SIZE(stm32_lptim_quadrature_modes),
- .get = stm32_lptim_get_quadrature_mode,
- .set = stm32_lptim_set_quadrature_mode,
-};
-
-static const char * const stm32_lptim_cnt_polarity[] = {
- "rising-edge", "falling-edge", "both-edges",
-};
-
-static int stm32_lptim_cnt_get_polarity(struct iio_dev *indio_dev,
- const struct iio_chan_spec *chan)
-{
- struct stm32_lptim_cnt *priv = iio_priv(indio_dev);
-
- return priv->polarity;
-}
-
-static int stm32_lptim_cnt_set_polarity(struct iio_dev *indio_dev,
- const struct iio_chan_spec *chan,
- unsigned int type)
-{
- struct stm32_lptim_cnt *priv = iio_priv(indio_dev);
-
- if (stm32_lptim_is_enabled(priv))
- return -EBUSY;
-
- priv->polarity = type;
-
- return 0;
-}
-
-static const struct iio_enum stm32_lptim_cnt_polarity_en = {
- .items = stm32_lptim_cnt_polarity,
- .num_items = ARRAY_SIZE(stm32_lptim_cnt_polarity),
- .get = stm32_lptim_cnt_get_polarity,
- .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)
-{
- struct stm32_lptim_cnt *priv = iio_priv(indio_dev);
-
- return snprintf(buf, PAGE_SIZE, "%u\n", priv->preset);
-}
-
-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)
-{
- 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);
- if (ret)
- return ret;
-
- if (priv->preset > STM32_LPTIM_MAX_ARR)
- return -EINVAL;
-
- return 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,
- },
- IIO_ENUM("polarity", IIO_SEPARATE, &stm32_lptim_cnt_polarity_en),
- IIO_ENUM_AVAILABLE("polarity", &stm32_lptim_cnt_polarity_en),
- IIO_ENUM("quadrature_mode", IIO_SEPARATE,
- &stm32_lptim_quadrature_mode_en),
- IIO_ENUM_AVAILABLE("quadrature_mode", &stm32_lptim_quadrature_mode_en),
- {}
-};
-
-static const struct iio_chan_spec stm32_lptim_enc_channels = {
- .type = IIO_COUNT,
- .channel = 0,
- .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
- BIT(IIO_CHAN_INFO_ENABLE) |
- BIT(IIO_CHAN_INFO_SCALE),
- .ext_info = stm32_lptim_enc_ext_info,
- .indexed = 1,
-};
-
-/* LP timer without encoder (counter only) */
-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,
- },
- IIO_ENUM("polarity", IIO_SEPARATE, &stm32_lptim_cnt_polarity_en),
- IIO_ENUM_AVAILABLE("polarity", &stm32_lptim_cnt_polarity_en),
- {}
-};
-
-static const struct iio_chan_spec stm32_lptim_cnt_channels = {
- .type = IIO_COUNT,
- .channel = 0,
- .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
- BIT(IIO_CHAN_INFO_ENABLE) |
- BIT(IIO_CHAN_INFO_SCALE),
- .ext_info = stm32_lptim_cnt_ext_info,
- .indexed = 1,
-};
-
-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;
-
- if (IS_ERR_OR_NULL(ddata))
- return -EINVAL;
-
- indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*priv));
- if (!indio_dev)
- return -ENOMEM;
-
- priv = iio_priv(indio_dev);
- priv->dev = &pdev->dev;
- priv->regmap = ddata->regmap;
- priv->clk = ddata->clk;
- priv->preset = STM32_LPTIM_MAX_ARR;
-
- indio_dev->name = dev_name(&pdev->dev);
- indio_dev->dev.parent = &pdev->dev;
- indio_dev->dev.of_node = pdev->dev.of_node;
- indio_dev->info = &stm32_lptim_cnt_iio_info;
- if (ddata->has_encoder)
- indio_dev->channels = &stm32_lptim_enc_channels;
- else
- indio_dev->channels = &stm32_lptim_cnt_channels;
- indio_dev->num_channels = 1;
-
- platform_set_drvdata(pdev, priv);
-
- return devm_iio_device_register(&pdev->dev, indio_dev);
-}
-
-#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");
projects / mirror_ubuntu-hirsute-kernel.git / commitdiff