Hi Jonathan,
i added support for parallax ping and laser ping sensors with just one pin
for trigger and echo signal.
After implementing it turned out that this one pin sensor requires a lot of
conditions and special treatment. But the calculation is still the same as
for srf04.
Should it be integrated into the existing srf04 driver or should i create a
new one for those single pin us sensors? Maybe together with a C module for
the calculations they have in common.
Regards,
Andreas
---
drivers/iio/proximity/srf04.c | 151 ++++++++++++++++++++++++++++++++++--------
1 file changed, 122 insertions(+), 29 deletions(-)
diff --git a/drivers/iio/proximity/srf04.c b/drivers/iio/proximity/srf04.c
index 01eb8cc63076..8bcc77a45965 100644
--- a/drivers/iio/proximity/srf04.c
+++ b/drivers/iio/proximity/srf04.c
@@ -49,7 +49,12 @@
#include <linux/iio/sysfs.h>
struct srf04_cfg {
- unsigned long trigger_pulse_us;
+ unsigned long trigger_pulse_us; /* length of trigger pulse */
+ int single_pin_mode; /* just one pin for trigger */
+ /* and echo */
+ int laserping_error; /* support error code in */
+ /* pulse width of laser */
+ /* ping sensors */
};
struct srf04_data {
@@ -67,10 +72,26 @@ struct srf04_data {
static const struct srf04_cfg srf04_cfg = {
.trigger_pulse_us = 10,
+ .single_pin_mode = 0,
+ .laserping_error = 0,
};
static const struct srf04_cfg mb_lv_cfg = {
.trigger_pulse_us = 20,
+ .single_pin_mode = 0,
+ .laserping_error = 0,
+};
+
+static const struct srf04_cfg pa_ping_cfg = {
+ .trigger_pulse_us = 5,
+ .single_pin_mode = 1,
+ .laserping_error = 0,
+};
+
+static const struct srf04_cfg pa_laser_ping_cfg = {
+ .trigger_pulse_us = 5,
+ .single_pin_mode = 1,
+ .laserping_error = 1,
};
static irqreturn_t srf04_handle_irq(int irq, void *dev_id)
@@ -96,6 +117,9 @@ static int srf04_read(struct srf04_data *data)
ktime_t ktime_dt;
u64 dt_ns;
u32 time_ns, distance_mm;
+ struct platform_device *pdev = container_of(data->dev,
+ struct platform_device, dev);
+ struct iio_dev *indio_dev = iio_priv_to_dev(data);
/*
* just one read-echo-cycle can take place at a time
@@ -110,30 +134,58 @@ static int srf04_read(struct srf04_data *data)
udelay(data->cfg->trigger_pulse_us);
gpiod_set_value(data->gpiod_trig, 0);
+ if (data->cfg->single_pin_mode) {
+ ret = gpiod_direction_input(data->gpiod_trig);
+ if (ret < 0) {
+ mutex_unlock(&data->lock);
+ return ret;
+ }
+
+ data->irqnr = gpiod_to_irq(data->gpiod_echo);
+ if (data->irqnr < 0) {
+ dev_err(data->dev, "gpiod_to_irq: %d\n", data->irqnr);
+ return data->irqnr;
+ }
+
+ ret = devm_request_irq(data->dev, data->irqnr, srf04_handle_irq,
+ IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
+ pdev->name, indio_dev);
+ if (ret < 0) {
+ dev_err(data->dev, "request_irq: %d\n", ret);
+ 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) {
- mutex_unlock(&data->lock);
- return ret;
- } else if (ret == 0) {
- mutex_unlock(&data->lock);
- return -ETIMEDOUT;
+ 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) {
- mutex_unlock(&data->lock);
- return ret;
- } else if (ret == 0) {
- mutex_unlock(&data->lock);
- return -ETIMEDOUT;
+ 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);
mutex_unlock(&data->lock);
+ if (data->cfg->single_pin_mode) {
+ free_irq(data->irqnr, indio_dev);
+
+ ret = gpiod_direction_output(data->gpiod_trig, GPIOD_OUT_LOW);
+ if (ret < 0)
+ return ret;
+ }
+
dt_ns = ktime_to_ns(ktime_dt);
/*
* measuring more than 6,45 meters is beyond the capabilities of
@@ -154,6 +206,25 @@ static int srf04_read(struct srf04_data *data)
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
@@ -176,6 +247,16 @@ static int srf04_read(struct srf04_data *data)
distance_mm = time_ns * 106 / 617176;
return distance_mm;
+
+err_reset_direction:
+ mutex_unlock(&data->lock);
+ if (data->cfg->single_pin_mode) {
+ free_irq(data->irqnr, indio_dev);
+
+ if (gpiod_direction_output(data->gpiod_trig, GPIOD_OUT_LOW))
+ dev_dbg(data->dev, "error in gpiod_direction_output\n");
+ }
+ return ret;
}
static int srf04_read_raw(struct iio_dev *indio_dev,
@@ -228,6 +309,8 @@ static const struct of_device_id of_srf04_match[] = {
{ .compatible = "maxbotix,mb1020", .data = &mb_lv_cfg},
{ .compatible = "maxbotix,mb1030", .data = &mb_lv_cfg},
{ .compatible = "maxbotix,mb1040", .data = &mb_lv_cfg},
+ { .compatible = "parallax,ping", .data = &pa_ping_cfg},
+ { .compatible = "parallax,laserping", .data = &pa_ping_cfg},
{},
};
@@ -261,11 +344,19 @@ static int srf04_probe(struct platform_device *pdev)
return PTR_ERR(data->gpiod_trig);
}
- data->gpiod_echo = devm_gpiod_get(dev, "echo", GPIOD_IN);
- if (IS_ERR(data->gpiod_echo)) {
- dev_err(dev, "failed to get echo-gpios: err=%ld\n",
+ /*
+ * some sensors come along with just one pin for triggering and the
+ * echo
+ */
+ if (data->cfg->single_pin_mode)
+ data->gpiod_echo = data->gpiod_trig;
+ else {
+ data->gpiod_echo = devm_gpiod_get(dev, "echo", GPIOD_IN);
+ if (IS_ERR(data->gpiod_echo)) {
+ dev_err(dev, "failed to get echo-gpios: err=%ld\n",
PTR_ERR(data->gpiod_echo));
- return PTR_ERR(data->gpiod_echo);
+ return PTR_ERR(data->gpiod_echo);
+ }
}
if (gpiod_cansleep(data->gpiod_echo)) {
@@ -273,18 +364,20 @@ static int srf04_probe(struct platform_device *pdev)
return -ENODEV;
}
- data->irqnr = gpiod_to_irq(data->gpiod_echo);
- if (data->irqnr < 0) {
- dev_err(data->dev, "gpiod_to_irq: %d\n", data->irqnr);
- return data->irqnr;
- }
-
- ret = devm_request_irq(dev, data->irqnr, srf04_handle_irq,
- IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
- pdev->name, indio_dev);
- if (ret < 0) {
- dev_err(data->dev, "request_irq: %d\n", ret);
- return ret;
+ if (!data->cfg->single_pin_mode) {
+ data->irqnr = gpiod_to_irq(data->gpiod_echo);
+ if (data->irqnr < 0) {
+ dev_err(data->dev, "gpiod_to_irq: %d\n", data->irqnr);
+ return data->irqnr;
+ }
+
+ ret = devm_request_irq(dev, data->irqnr, srf04_handle_irq,
+ IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
+ pdev->name, indio_dev);
+ if (ret < 0) {
+ dev_err(data->dev, "request_irq: %d\n", ret);
+ return ret;
+ }
}
platform_set_drvdata(pdev, indio_dev);
--
2.11.0
