@@ -29,6 +29,16 @@ config 104_QUAD_8
The base port addresses for the devices may be configured via the base
array module parameter.
+config PULSE_CNT
+ tristate "Pulse counter driver"
+ depends on GPIOLIB
+ help
+ Select this option to enable pulse counter driver. Any interrupt source
+ can be used by this driver as the pulse source.
+
+ To compile this driver as a module, choose M here: the
+ module will be called gpio-pulse-cnt.
+
config STM32_TIMER_CNT
tristate "STM32 Timer encoder counter driver"
depends on MFD_STM32_TIMERS || COMPILE_TEST
@@ -6,6 +6,7 @@
obj-$(CONFIG_COUNTER) += counter.o
obj-$(CONFIG_104_QUAD_8) += 104-quad-8.o
+obj-$(CONFIG_PULSE_CNT) += pulse-cnt.o
obj-$(CONFIG_STM32_TIMER_CNT) += stm32-timer-cnt.o
obj-$(CONFIG_STM32_LPTIMER_CNT) += stm32-lptimer-cnt.o
obj-$(CONFIG_TI_EQEP) += ti-eqep.o
new file mode 100644
@@ -0,0 +1,235 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2021 Pengutronix, Oleksij Rempel <kernel@pengutronix.de>
+ */
+
+#include <linux/counter.h>
+#include <linux/gpio/consumer.h>
+#include <linux/interrupt.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+
+#define PULSE_CNT_NAME "pulse-cnt"
+
+struct pulse_cnt_priv {
+ struct counter_device counter;
+ struct counter_ops ops;
+ struct gpio_desc *gpio;
+ int irq;
+ bool enabled;
+ atomic_t count;
+};
+
+static irqreturn_t pulse_cnt_isr(int irq, void *dev_id)
+{
+ struct pulse_cnt_priv *priv = dev_id;
+
+ atomic_inc(&priv->count);
+
+ return IRQ_HANDLED;
+}
+
+static ssize_t pulse_cnt_enable_read(struct counter_device *counter,
+ struct counter_count *count, void *private,
+ char *buf)
+{
+ struct pulse_cnt_priv *priv = counter->priv;
+
+ return sysfs_emit(buf, "%d\n", priv->enabled);
+}
+
+static ssize_t pulse_cnt_enable_write(struct counter_device *counter,
+ struct counter_count *count,
+ void *private, const char *buf,
+ size_t len)
+{
+ struct pulse_cnt_priv *priv = counter->priv;
+ bool enable;
+ ssize_t ret;
+
+ ret = kstrtobool(buf, &enable);
+ if (ret)
+ return ret;
+
+ if (priv->enabled == enable)
+ return len;
+
+ if (enable) {
+ priv->enabled = enable;
+ enable_irq(priv->irq);
+ } else {
+ disable_irq(priv->irq);
+ priv->enabled = enable;
+ }
+
+ return len;
+}
+
+static const struct counter_count_ext pulse_cnt_ext[] = {
+ {
+ .name = "enable",
+ .read = pulse_cnt_enable_read,
+ .write = pulse_cnt_enable_write,
+ },
+};
+
+static enum counter_synapse_action pulse_cnt_synapse_actionss[] = {
+ COUNTER_SYNAPSE_ACTION_RISING_EDGE,
+};
+
+static int pulse_cnt_action_get(struct counter_device *counter,
+ struct counter_count *count,
+ struct counter_synapse *synapse,
+ size_t *action)
+{
+ *action = COUNTER_SYNAPSE_ACTION_RISING_EDGE;
+
+ return 0;
+}
+
+static int pulse_cnt_read(struct counter_device *counter,
+ struct counter_count *count,
+ unsigned long *val)
+{
+ struct pulse_cnt_priv *priv = counter->priv;
+
+ *val = atomic_read(&priv->count);
+
+ return 0;
+}
+
+static int pulse_cnt_write(struct counter_device *counter,
+ struct counter_count *count,
+ const unsigned long val)
+{
+ struct pulse_cnt_priv *priv = counter->priv;
+
+ atomic_set(&priv->count, val);
+
+ return 0;
+}
+
+static int pulse_cnt_function_get(struct counter_device *counter,
+ struct counter_count *count, size_t *function)
+{
+ *function = COUNTER_COUNT_FUNCTION_INCREASE;
+
+ return 0;
+}
+
+static int pulse_cnt_signal_read(struct counter_device *counter,
+ struct counter_signal *signal,
+ enum counter_signal_value *val)
+{
+ struct pulse_cnt_priv *priv = counter->priv;
+ int ret;
+
+ ret = gpiod_get_value(priv->gpio);
+ if (ret < 0)
+ return ret;
+
+ *val = ret ? COUNTER_SIGNAL_HIGH : COUNTER_SIGNAL_LOW;
+
+ return 0;
+}
+
+static struct counter_signal pulse_cnt_signals[] = {
+ {
+ .id = 0,
+ .name = "Channel 0 signal",
+ },
+};
+
+static struct counter_synapse pulse_cnt_synapses[] = {
+ {
+ .actions_list = pulse_cnt_synapse_actionss,
+ .num_actions = ARRAY_SIZE(pulse_cnt_synapse_actionss),
+ .signal = &pulse_cnt_signals[0]
+ },
+};
+
+static enum counter_count_function pulse_cnt_functions[] = {
+ COUNTER_COUNT_FUNCTION_INCREASE,
+};
+
+static struct counter_count pulse_cnts[] = {
+ {
+ .id = 0,
+ .name = "Channel 1 Count",
+ .functions_list = pulse_cnt_functions,
+ .num_functions = ARRAY_SIZE(pulse_cnt_functions),
+ .synapses = pulse_cnt_synapses,
+ .num_synapses = ARRAY_SIZE(pulse_cnt_synapses),
+ .ext = pulse_cnt_ext,
+ .num_ext = ARRAY_SIZE(pulse_cnt_ext),
+ },
+};
+
+static int pulse_cnt_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct pulse_cnt_priv *priv;
+ int ret;
+
+ priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->irq = platform_get_irq(pdev, 0);
+ if (priv->irq < 0) {
+ dev_err(dev, "failed to map GPIO to IRQ: %d\n", priv->irq);
+ return priv->irq;
+ }
+
+ priv->gpio = devm_gpiod_get_optional(dev, NULL, GPIOD_IN);
+ if (IS_ERR(priv->gpio))
+ return dev_err_probe(dev, PTR_ERR(priv->gpio), "failed to get gpio\n");
+
+ priv->ops.action_get = pulse_cnt_action_get;
+ priv->ops.count_read = pulse_cnt_read;
+ priv->ops.count_write = pulse_cnt_write;
+ priv->ops.function_get = pulse_cnt_function_get;
+ if (priv->gpio)
+ priv->ops.signal_read = pulse_cnt_signal_read;
+
+ priv->counter.name = dev_name(dev);
+ priv->counter.parent = dev;
+ priv->counter.ops = &priv->ops;
+ priv->counter.counts = pulse_cnts;
+ priv->counter.num_counts = ARRAY_SIZE(pulse_cnts);
+ priv->counter.signals = pulse_cnt_signals;
+ priv->counter.num_signals = ARRAY_SIZE(pulse_cnt_signals);
+ priv->counter.priv = priv;
+
+ irq_set_status_flags(priv->irq, IRQ_NOAUTOEN);
+ ret = devm_request_irq(dev, priv->irq, pulse_cnt_isr,
+ IRQF_TRIGGER_RISING | IRQF_NO_THREAD,
+ PULSE_CNT_NAME, priv);
+ if (ret)
+ return ret;
+
+ platform_set_drvdata(pdev, priv);
+
+ return devm_counter_register(dev, &priv->counter);
+}
+
+static const struct of_device_id pulse_cnt_of_match[] = {
+ { .compatible = "virtual,pulse-counter", },
+ {}
+};
+MODULE_DEVICE_TABLE(of, pulse_cnt_of_match);
+
+static struct platform_driver pulse_cnt_driver = {
+ .probe = pulse_cnt_probe,
+ .driver = {
+ .name = PULSE_CNT_NAME,
+ .of_match_table = pulse_cnt_of_match,
+ },
+};
+module_platform_driver(pulse_cnt_driver);
+
+MODULE_ALIAS("platform:pulse-counter");
+MODULE_AUTHOR("Oleksij Rempel <o.rempel@pengutronix.de>");
+MODULE_DESCRIPTION("Pulse counter driver");
+MODULE_LICENSE("GPL v2");