Commit d3bf6045 authored by Andreas Klinger's avatar Andreas Klinger Committed by Greg Kroah-Hartman

iio: hx711: add triggered buffer support

Add buffer to device data struct and add trigger function

Data format is quite simple:
      voltage - channel 0   32 Bit
      voltage - channel 1   32 Bit
      timestamp             64 Bit

Using both channels at the same time is working quite slow because of
changing the channel which needs a dummy read.
Signed-off-by: default avatarAndreas Klinger <ak@it-klinger.de>
Signed-off-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 8bcf024f
...@@ -319,6 +319,8 @@ config HI8435 ...@@ -319,6 +319,8 @@ config HI8435
config HX711 config HX711
tristate "AVIA HX711 ADC for weight cells" tristate "AVIA HX711 ADC for weight cells"
depends on GPIOLIB depends on GPIOLIB
select IIO_BUFFER
select IIO_TRIGGERED_BUFFER
help help
If you say yes here you get support for AVIA HX711 ADC which is used If you say yes here you get support for AVIA HX711 ADC which is used
for weigh cells for weigh cells
......
...@@ -24,6 +24,9 @@ ...@@ -24,6 +24,9 @@
#include <linux/delay.h> #include <linux/delay.h>
#include <linux/iio/iio.h> #include <linux/iio/iio.h>
#include <linux/iio/sysfs.h> #include <linux/iio/sysfs.h>
#include <linux/iio/buffer.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/triggered_buffer.h>
#include <linux/gpio/consumer.h> #include <linux/gpio/consumer.h>
#include <linux/regulator/consumer.h> #include <linux/regulator/consumer.h>
...@@ -89,6 +92,11 @@ struct hx711_data { ...@@ -89,6 +92,11 @@ struct hx711_data {
int gain_set; /* gain set on device */ int gain_set; /* gain set on device */
int gain_chan_a; /* gain for channel A */ int gain_chan_a; /* gain for channel A */
struct mutex lock; struct mutex lock;
/*
* triggered buffer
* 2x32-bit channel + 64-bit timestamp
*/
u32 buffer[4];
}; };
static int hx711_cycle(struct hx711_data *hx711_data) static int hx711_cycle(struct hx711_data *hx711_data)
...@@ -236,34 +244,40 @@ static int hx711_set_gain_for_channel(struct hx711_data *hx711_data, int chan) ...@@ -236,34 +244,40 @@ static int hx711_set_gain_for_channel(struct hx711_data *hx711_data, int chan)
return 0; return 0;
} }
static int hx711_reset_read(struct hx711_data *hx711_data, int chan)
{
int ret;
int val;
/*
* hx711_reset() must be called from here
* because it could be calling hx711_read() by itself
*/
if (hx711_reset(hx711_data)) {
dev_err(hx711_data->dev, "reset failed!");
return -EIO;
}
ret = hx711_set_gain_for_channel(hx711_data, chan);
if (ret < 0)
return ret;
val = hx711_read(hx711_data);
return val;
}
static int hx711_read_raw(struct iio_dev *indio_dev, static int hx711_read_raw(struct iio_dev *indio_dev,
const struct iio_chan_spec *chan, const struct iio_chan_spec *chan,
int *val, int *val2, long mask) int *val, int *val2, long mask)
{ {
struct hx711_data *hx711_data = iio_priv(indio_dev); struct hx711_data *hx711_data = iio_priv(indio_dev);
int ret;
switch (mask) { switch (mask) {
case IIO_CHAN_INFO_RAW: case IIO_CHAN_INFO_RAW:
mutex_lock(&hx711_data->lock); mutex_lock(&hx711_data->lock);
/* *val = hx711_reset_read(hx711_data, chan->channel);
* hx711_reset() must be called from here
* because it could be calling hx711_read() by itself
*/
if (hx711_reset(hx711_data)) {
mutex_unlock(&hx711_data->lock);
dev_err(hx711_data->dev, "reset failed!");
return -EIO;
}
ret = hx711_set_gain_for_channel(hx711_data, chan->channel);
if (ret < 0) {
mutex_unlock(&hx711_data->lock);
return ret;
}
*val = hx711_read(hx711_data);
mutex_unlock(&hx711_data->lock); mutex_unlock(&hx711_data->lock);
...@@ -339,6 +353,36 @@ static int hx711_write_raw_get_fmt(struct iio_dev *indio_dev, ...@@ -339,6 +353,36 @@ static int hx711_write_raw_get_fmt(struct iio_dev *indio_dev,
return IIO_VAL_INT_PLUS_NANO; return IIO_VAL_INT_PLUS_NANO;
} }
static irqreturn_t hx711_trigger(int irq, void *p)
{
struct iio_poll_func *pf = p;
struct iio_dev *indio_dev = pf->indio_dev;
struct hx711_data *hx711_data = iio_priv(indio_dev);
int i, j = 0;
mutex_lock(&hx711_data->lock);
memset(hx711_data->buffer, 0, sizeof(hx711_data->buffer));
for (i = 0; i < indio_dev->masklength; i++) {
if (!test_bit(i, indio_dev->active_scan_mask))
continue;
hx711_data->buffer[j] = hx711_reset_read(hx711_data,
indio_dev->channels[i].channel);
j++;
}
iio_push_to_buffers_with_timestamp(indio_dev, hx711_data->buffer,
pf->timestamp);
mutex_unlock(&hx711_data->lock);
iio_trigger_notify_done(indio_dev->trig);
return IRQ_HANDLED;
}
static ssize_t hx711_scale_available_show(struct device *dev, static ssize_t hx711_scale_available_show(struct device *dev,
struct device_attribute *attr, struct device_attribute *attr,
char *buf) char *buf)
...@@ -387,6 +431,13 @@ static const struct iio_chan_spec hx711_chan_spec[] = { ...@@ -387,6 +431,13 @@ static const struct iio_chan_spec hx711_chan_spec[] = {
.indexed = 1, .indexed = 1,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
.scan_index = 0,
.scan_type = {
.sign = 'u',
.realbits = 24,
.storagebits = 32,
.endianness = IIO_CPU,
},
}, },
{ {
.type = IIO_VOLTAGE, .type = IIO_VOLTAGE,
...@@ -394,7 +445,15 @@ static const struct iio_chan_spec hx711_chan_spec[] = { ...@@ -394,7 +445,15 @@ static const struct iio_chan_spec hx711_chan_spec[] = {
.indexed = 1, .indexed = 1,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
.scan_index = 1,
.scan_type = {
.sign = 'u',
.realbits = 24,
.storagebits = 32,
.endianness = IIO_CPU,
},
}, },
IIO_CHAN_SOFT_TIMESTAMP(2),
}; };
static int hx711_probe(struct platform_device *pdev) static int hx711_probe(struct platform_device *pdev)
...@@ -459,10 +518,9 @@ static int hx711_probe(struct platform_device *pdev) ...@@ -459,10 +518,9 @@ static int hx711_probe(struct platform_device *pdev)
* 1 LSB = (AVDD * 100) / GAIN / 1678 [10^-9 mV] * 1 LSB = (AVDD * 100) / GAIN / 1678 [10^-9 mV]
*/ */
ret = regulator_get_voltage(hx711_data->reg_avdd); ret = regulator_get_voltage(hx711_data->reg_avdd);
if (ret < 0) { if (ret < 0)
regulator_disable(hx711_data->reg_avdd); goto error_regulator;
return ret;
}
/* we need 10^-9 mV */ /* we need 10^-9 mV */
ret *= 100; ret *= 100;
...@@ -482,12 +540,27 @@ static int hx711_probe(struct platform_device *pdev) ...@@ -482,12 +540,27 @@ static int hx711_probe(struct platform_device *pdev)
indio_dev->channels = hx711_chan_spec; indio_dev->channels = hx711_chan_spec;
indio_dev->num_channels = ARRAY_SIZE(hx711_chan_spec); indio_dev->num_channels = ARRAY_SIZE(hx711_chan_spec);
ret = iio_triggered_buffer_setup(indio_dev, iio_pollfunc_store_time,
hx711_trigger, NULL);
if (ret < 0) {
dev_err(dev, "setup of iio triggered buffer failed\n");
goto error_regulator;
}
ret = iio_device_register(indio_dev); ret = iio_device_register(indio_dev);
if (ret < 0) { if (ret < 0) {
dev_err(dev, "Couldn't register the device\n"); dev_err(dev, "Couldn't register the device\n");
regulator_disable(hx711_data->reg_avdd); goto error_buffer;
} }
return 0;
error_buffer:
iio_triggered_buffer_cleanup(indio_dev);
error_regulator:
regulator_disable(hx711_data->reg_avdd);
return ret; return ret;
} }
...@@ -501,6 +574,8 @@ static int hx711_remove(struct platform_device *pdev) ...@@ -501,6 +574,8 @@ static int hx711_remove(struct platform_device *pdev)
iio_device_unregister(indio_dev); iio_device_unregister(indio_dev);
iio_triggered_buffer_cleanup(indio_dev);
regulator_disable(hx711_data->reg_avdd); regulator_disable(hx711_data->reg_avdd);
return 0; return 0;
......
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