Adding upstream version 5.10.209.upstream/5.10.209upstream

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

1 files changed, 333 insertions, 0 deletions

diff --git a/drivers/iio/proximity/ping.c b/drivers/iio/proximity/ping.c
new file mode 100644
index 000000000..1283ac1c2
--- /dev/null
+++ b/drivers/iio/proximity/ping.c
@@ -0,0 +1,333 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * PING: ultrasonic sensor for distance measuring by using only one GPIOs
+ *
+ * Copyright (c) 2019 Andreas Klinger <ak@it-klinger.de>
+ *
+ * For details about the devices see:
+ * http://parallax.com/sites/default/files/downloads/28041-LaserPING-2m-Rangefinder-Guide.pdf
+ * http://parallax.com/sites/default/files/downloads/28015-PING-Documentation-v1.6.pdf
+ *
+ * the measurement cycle as timing diagram looks like:
+ *
+ * GPIO      ___              ________________________
+ * ping:  __/   \____________/                        \________________
+ *          ^   ^            ^                        ^
+ *          |<->|            interrupt                interrupt
+ *         udelay(5)         (ts_rising)              (ts_falling)
+ *                           |<---------------------->|
+ *                           .  pulse time measured   .
+ *                           .  --> one round trip of ultra sonic waves
+ * ultra                     .                        .
+ * sonic            _   _   _.                        .
+ * burst: _________/ \_/ \_/ \_________________________________________
+ *                                                    .
+ * ultra                                              .
+ * sonic                                     _   _   _.
+ * echo:  __________________________________/ \_/ \_/ \________________
+ */
+#include <linux/err.h>
+#include <linux/gpio/consumer.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/property.h>
+#include <linux/sched.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+
+struct ping_cfg {
+	unsigned long	trigger_pulse_us;	/* length of trigger pulse */
+	int		laserping_error;	/* support error code in */
+						/*   pulse width of laser */
+						/*   ping sensors */
+	s64		timeout_ns;		/* timeout in ns */
+};
+
+struct ping_data {
+	struct device		*dev;
+	struct gpio_desc	*gpiod_ping;
+	struct mutex		lock;
+	int			irqnr;
+	ktime_t			ts_rising;
+	ktime_t			ts_falling;
+	struct completion	rising;
+	struct completion	falling;
+	const struct ping_cfg	*cfg;
+};
+
+static const struct ping_cfg pa_ping_cfg = {
+	.trigger_pulse_us	= 5,
+	.laserping_error	= 0,
+	.timeout_ns		= 18500000,	/* 3 meters */
+};
+
+static const struct ping_cfg pa_laser_ping_cfg = {
+	.trigger_pulse_us	= 5,
+	.laserping_error	= 1,
+	.timeout_ns		= 15500000,	/* 2 meters plus error codes */
+};
+
+static irqreturn_t ping_handle_irq(int irq, void *dev_id)
+{
+	struct iio_dev *indio_dev = dev_id;
+	struct ping_data *data = iio_priv(indio_dev);
+	ktime_t now = ktime_get();
+
+	if (gpiod_get_value(data->gpiod_ping)) {
+		data->ts_rising = now;
+		complete(&data->rising);
+	} else {
+		data->ts_falling = now;
+		complete(&data->falling);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static int ping_read(struct iio_dev *indio_dev)
+{
+	struct ping_data *data = iio_priv(indio_dev);
+	int ret;
+	ktime_t ktime_dt;
+	s64 dt_ns;
+	u32 time_ns, distance_mm;
+	struct platform_device *pdev = to_platform_device(data->dev);
+
+	/*
+	 * just one read-echo-cycle can take place at a time
+	 * ==> lock against concurrent reading calls
+	 */
+	mutex_lock(&data->lock);
+
+	reinit_completion(&data->rising);
+	reinit_completion(&data->falling);
+
+	gpiod_set_value(data->gpiod_ping, 1);
+	udelay(data->cfg->trigger_pulse_us);
+	gpiod_set_value(data->gpiod_ping, 0);
+
+	ret = gpiod_direction_input(data->gpiod_ping);
+	if (ret < 0) {
+		mutex_unlock(&data->lock);
+		return ret;
+	}
+
+	data->irqnr = gpiod_to_irq(data->gpiod_ping);
+	if (data->irqnr < 0) {
+		dev_err(data->dev, "gpiod_to_irq: %d\n", data->irqnr);
+		mutex_unlock(&data->lock);
+		return data->irqnr;
+	}
+
+	ret = request_irq(data->irqnr, ping_handle_irq,
+				IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
+							pdev->name, indio_dev);
+	if (ret < 0) {
+		dev_err(data->dev, "request_irq: %d\n", ret);
+		mutex_unlock(&data->lock);
+		return ret;
+	}
+
+	/* it should not take more than 20 ms until echo is rising */
+	ret = wait_for_completion_killable_timeout(&data->rising, HZ/50);
+	if (ret < 0)
+		goto err_reset_direction;
+	else if (ret == 0) {
+		ret = -ETIMEDOUT;
+		goto err_reset_direction;
+	}
+
+	/* it cannot take more than 50 ms until echo is falling */
+	ret = wait_for_completion_killable_timeout(&data->falling, HZ/20);
+	if (ret < 0)
+		goto err_reset_direction;
+	else if (ret == 0) {
+		ret = -ETIMEDOUT;
+		goto err_reset_direction;
+	}
+
+	ktime_dt = ktime_sub(data->ts_falling, data->ts_rising);
+
+	free_irq(data->irqnr, indio_dev);
+
+	ret = gpiod_direction_output(data->gpiod_ping, GPIOD_OUT_LOW);
+	if (ret < 0) {
+		mutex_unlock(&data->lock);
+		return ret;
+	}
+
+	mutex_unlock(&data->lock);
+
+	dt_ns = ktime_to_ns(ktime_dt);
+	if (dt_ns > data->cfg->timeout_ns) {
+		dev_dbg(data->dev, "distance out of range: dt=%lldns\n",
+								dt_ns);
+		return -EIO;
+	}
+
+	time_ns = dt_ns;
+
+	/*
+	 * read error code of laser ping sensor and give users chance to
+	 * figure out error by using dynamic debuggging
+	 */
+	if (data->cfg->laserping_error) {
+		if ((time_ns > 12500000) && (time_ns <= 13500000)) {
+			dev_dbg(data->dev, "target too close or to far\n");
+			return -EIO;
+		}
+		if ((time_ns > 13500000) && (time_ns <= 14500000)) {
+			dev_dbg(data->dev, "internal sensor error\n");
+			return -EIO;
+		}
+		if ((time_ns > 14500000) && (time_ns <= 15500000)) {
+			dev_dbg(data->dev, "internal sensor timeout\n");
+			return -EIO;
+		}
+	}
+
+	/*
+	 * the speed as function of the temperature is approximately:
+	 *
+	 * speed = 331,5 + 0,6 * Temp
+	 *   with Temp in °C
+	 *   and speed in m/s
+	 *
+	 * use 343,5 m/s as ultrasonic speed at 20 °C here in absence of the
+	 * temperature
+	 *
+	 * therefore:
+	 *             time     343,5     time * 232
+	 * distance = ------ * ------- = ------------
+	 *             10^6         2        1350800
+	 *   with time in ns
+	 *   and distance in mm (one way)
+	 *
+	 * because we limit to 3 meters the multiplication with 232 just
+	 * fits into 32 bit
+	 */
+	distance_mm = time_ns * 232 / 1350800;
+
+	return distance_mm;
+
+err_reset_direction:
+	free_irq(data->irqnr, indio_dev);
+	mutex_unlock(&data->lock);
+
+	if (gpiod_direction_output(data->gpiod_ping, GPIOD_OUT_LOW))
+		dev_dbg(data->dev, "error in gpiod_direction_output\n");
+	return ret;
+}
+
+static int ping_read_raw(struct iio_dev *indio_dev,
+			    struct iio_chan_spec const *channel, int *val,
+			    int *val2, long info)
+{
+	int ret;
+
+	if (channel->type != IIO_DISTANCE)
+		return -EINVAL;
+
+	switch (info) {
+	case IIO_CHAN_INFO_RAW:
+		ret = ping_read(indio_dev);
+		if (ret < 0)
+			return ret;
+		*val = ret;
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_SCALE:
+		/*
+		 * maximum resolution in datasheet is 1 mm
+		 * 1 LSB is 1 mm
+		 */
+		*val = 0;
+		*val2 = 1000;
+		return IIO_VAL_INT_PLUS_MICRO;
+	default:
+		return -EINVAL;
+	}
+}
+
+static const struct iio_info ping_iio_info = {
+	.read_raw		= ping_read_raw,
+};
+
+static const struct iio_chan_spec ping_chan_spec[] = {
+	{
+		.type = IIO_DISTANCE,
+		.info_mask_separate =
+				BIT(IIO_CHAN_INFO_RAW) |
+				BIT(IIO_CHAN_INFO_SCALE),
+	},
+};
+
+static const struct of_device_id of_ping_match[] = {
+	{ .compatible = "parallax,ping", .data = &pa_ping_cfg},
+	{ .compatible = "parallax,laserping", .data = &pa_laser_ping_cfg},
+	{},
+};
+
+MODULE_DEVICE_TABLE(of, of_ping_match);
+
+static int ping_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct ping_data *data;
+	struct iio_dev *indio_dev;
+
+	indio_dev = devm_iio_device_alloc(dev, sizeof(struct ping_data));
+	if (!indio_dev) {
+		dev_err(dev, "failed to allocate IIO device\n");
+		return -ENOMEM;
+	}
+
+	data = iio_priv(indio_dev);
+	data->dev = dev;
+	data->cfg = of_device_get_match_data(dev);
+
+	mutex_init(&data->lock);
+	init_completion(&data->rising);
+	init_completion(&data->falling);
+
+	data->gpiod_ping = devm_gpiod_get(dev, "ping", GPIOD_OUT_LOW);
+	if (IS_ERR(data->gpiod_ping)) {
+		dev_err(dev, "failed to get ping-gpios: err=%ld\n",
+						PTR_ERR(data->gpiod_ping));
+		return PTR_ERR(data->gpiod_ping);
+	}
+
+	if (gpiod_cansleep(data->gpiod_ping)) {
+		dev_err(data->dev, "cansleep-GPIOs not supported\n");
+		return -ENODEV;
+	}
+
+	platform_set_drvdata(pdev, indio_dev);
+
+	indio_dev->name = "ping";
+	indio_dev->info = &ping_iio_info;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->channels = ping_chan_spec;
+	indio_dev->num_channels = ARRAY_SIZE(ping_chan_spec);
+
+	return devm_iio_device_register(dev, indio_dev);
+}
+
+static struct platform_driver ping_driver = {
+	.probe		= ping_probe,
+	.driver		= {
+		.name		= "ping-gpio",
+		.of_match_table	= of_ping_match,
+	},
+};
+
+module_platform_driver(ping_driver);
+
+MODULE_AUTHOR("Andreas Klinger <ak@it-klinger.de>");
+MODULE_DESCRIPTION("PING sensors for distance measuring using one GPIOs");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:ping");