| Message ID | 20171130214342.GA27320@arbeit (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, 30 Nov 2017 22:43:42 +0100 Andreas Klinger <ak@it-klinger.de> wrote: > 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: Andreas Klinger <ak@it-klinger.de> Locking issues and a data positioning issue. See inline. Thanks, Jonathan > --- > drivers/iio/adc/Kconfig | 2 + > drivers/iio/adc/hx711.c | 106 ++++++++++++++++++++++++++++++++++++++++-------- > 2 files changed, 90 insertions(+), 18 deletions(-) > > diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig > index af4fc1279409..a83642e517d5 100644 > --- a/drivers/iio/adc/Kconfig > +++ b/drivers/iio/adc/Kconfig > @@ -316,6 +316,8 @@ config HI8435 > config HX711 > tristate "AVIA HX711 ADC for weight cells" > depends on GPIOLIB > + select IIO_BUFFER > + select IIO_TRIGGERED_BUFFER > help > If you say yes here you get support for AVIA HX711 ADC which is used > for weigh cells > diff --git a/drivers/iio/adc/hx711.c b/drivers/iio/adc/hx711.c > index d10b9f13d557..d773fd69a76d 100644 > --- a/drivers/iio/adc/hx711.c > +++ b/drivers/iio/adc/hx711.c > @@ -24,6 +24,9 @@ > #include <linux/delay.h> > #include <linux/iio/iio.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/regulator/consumer.h> > > @@ -89,6 +92,11 @@ struct hx711_data { > int gain_set; /* gain set on device */ > int gain_chan_a; /* gain for channel A */ > struct mutex lock; > + /* > + * triggered buffer > + * 2x32-bit channel + 2x32-bit timestamp > + */ > + u32 buffer[4]; > }; > > static int hx711_cycle(struct hx711_data *hx711_data) > @@ -236,34 +244,43 @@ static int hx711_set_gain_for_channel(struct hx711_data *hx711_data, int chan) > 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)) { Mutex unlocks but no lock in a function is an issue... Also I think you'll just be unlocking twice. > + mutex_unlock(&hx711_data->lock); > + dev_err(hx711_data->dev, "reset failed!"); > + return -EIO; > + } > + > + ret = hx711_set_gain_for_channel(hx711_data, chan); > + if (ret < 0) { > + mutex_unlock(&hx711_data->lock); > + return ret; > + } > + > + val = hx711_read(hx711_data); > + > + return val; > +} > + > static int hx711_read_raw(struct iio_dev *indio_dev, > const struct iio_chan_spec *chan, > int *val, int *val2, long mask) > { > struct hx711_data *hx711_data = iio_priv(indio_dev); > - int ret; > > switch (mask) { > case IIO_CHAN_INFO_RAW: > mutex_lock(&hx711_data->lock); > > - /* > - * 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); > + *val = hx711_reset_read(hx711_data, chan->channel); > > mutex_unlock(&hx711_data->lock); > > @@ -339,6 +356,35 @@ static int hx711_write_raw_get_fmt(struct iio_dev *indio_dev, > 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; > + > + 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; Expectation of IIO is that if you had only the second channel on it's data would be found at the 0 position in the buffer. > + > + hx711_data->buffer[i] = hx711_reset_read(hx711_data, > + indio_dev->channels[i].channel); > + } > + > + 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, > struct device_attribute *attr, > char *buf) > @@ -387,6 +433,14 @@ static const struct iio_chan_spec hx711_chan_spec[] = { > .indexed = 1, > .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), > .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), > + .scan_index = 0, > + .scan_type = { > + .sign = 'u', > + .realbits = 24, > + .storagebits = 32, > + .shift = 0, > + .endianness = IIO_CPU, > + }, > }, > { > .type = IIO_VOLTAGE, > @@ -394,7 +448,16 @@ static const struct iio_chan_spec hx711_chan_spec[] = { > .indexed = 1, > .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), > .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), > + .scan_index = 1, > + .scan_type = { > + .sign = 'u', > + .realbits = 24, > + .storagebits = 32, > + .shift = 0, > + .endianness = IIO_CPU, > + }, > }, > + IIO_CHAN_SOFT_TIMESTAMP(2), > }; > > static int hx711_probe(struct platform_device *pdev) > @@ -482,6 +545,13 @@ static int hx711_probe(struct platform_device *pdev) > indio_dev->channels = hx711_chan_spec; > indio_dev->num_channels = ARRAY_SIZE(hx711_chan_spec); > > + ret = devm_iio_triggered_buffer_setup(dev, indio_dev, > + iio_pollfunc_store_time, hx711_trigger, NULL); > + if (ret < 0) { > + dev_err(dev, "setup of iio triggered buffer failed\n"); > + return ret; > + } > + > ret = iio_device_register(indio_dev); > if (ret < 0) { > dev_err(dev, "Couldn't register the device\n"); -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig index af4fc1279409..a83642e517d5 100644 --- a/drivers/iio/adc/Kconfig +++ b/drivers/iio/adc/Kconfig @@ -316,6 +316,8 @@ config HI8435 config HX711 tristate "AVIA HX711 ADC for weight cells" depends on GPIOLIB + select IIO_BUFFER + select IIO_TRIGGERED_BUFFER help If you say yes here you get support for AVIA HX711 ADC which is used for weigh cells diff --git a/drivers/iio/adc/hx711.c b/drivers/iio/adc/hx711.c index d10b9f13d557..d773fd69a76d 100644 --- a/drivers/iio/adc/hx711.c +++ b/drivers/iio/adc/hx711.c @@ -24,6 +24,9 @@ #include <linux/delay.h> #include <linux/iio/iio.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/regulator/consumer.h> @@ -89,6 +92,11 @@ struct hx711_data { int gain_set; /* gain set on device */ int gain_chan_a; /* gain for channel A */ struct mutex lock; + /* + * triggered buffer + * 2x32-bit channel + 2x32-bit timestamp + */ + u32 buffer[4]; }; static int hx711_cycle(struct hx711_data *hx711_data) @@ -236,34 +244,43 @@ static int hx711_set_gain_for_channel(struct hx711_data *hx711_data, int chan) 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)) { + mutex_unlock(&hx711_data->lock); + dev_err(hx711_data->dev, "reset failed!"); + return -EIO; + } + + ret = hx711_set_gain_for_channel(hx711_data, chan); + if (ret < 0) { + mutex_unlock(&hx711_data->lock); + return ret; + } + + val = hx711_read(hx711_data); + + return val; +} + static int hx711_read_raw(struct iio_dev *indio_dev, const struct iio_chan_spec *chan, int *val, int *val2, long mask) { struct hx711_data *hx711_data = iio_priv(indio_dev); - int ret; switch (mask) { case IIO_CHAN_INFO_RAW: mutex_lock(&hx711_data->lock); - /* - * 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); + *val = hx711_reset_read(hx711_data, chan->channel); mutex_unlock(&hx711_data->lock); @@ -339,6 +356,35 @@ static int hx711_write_raw_get_fmt(struct iio_dev *indio_dev, 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; + + 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[i] = hx711_reset_read(hx711_data, + indio_dev->channels[i].channel); + } + + 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, struct device_attribute *attr, char *buf) @@ -387,6 +433,14 @@ static const struct iio_chan_spec hx711_chan_spec[] = { .indexed = 1, .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), + .scan_index = 0, + .scan_type = { + .sign = 'u', + .realbits = 24, + .storagebits = 32, + .shift = 0, + .endianness = IIO_CPU, + }, }, { .type = IIO_VOLTAGE, @@ -394,7 +448,16 @@ static const struct iio_chan_spec hx711_chan_spec[] = { .indexed = 1, .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), + .scan_index = 1, + .scan_type = { + .sign = 'u', + .realbits = 24, + .storagebits = 32, + .shift = 0, + .endianness = IIO_CPU, + }, }, + IIO_CHAN_SOFT_TIMESTAMP(2), }; static int hx711_probe(struct platform_device *pdev) @@ -482,6 +545,13 @@ static int hx711_probe(struct platform_device *pdev) indio_dev->channels = hx711_chan_spec; indio_dev->num_channels = ARRAY_SIZE(hx711_chan_spec); + ret = devm_iio_triggered_buffer_setup(dev, indio_dev, + iio_pollfunc_store_time, hx711_trigger, NULL); + if (ret < 0) { + dev_err(dev, "setup of iio triggered buffer failed\n"); + return ret; + } + ret = iio_device_register(indio_dev); if (ret < 0) { dev_err(dev, "Couldn't register the device\n");
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: Andreas Klinger <ak@it-klinger.de> --- drivers/iio/adc/Kconfig | 2 + drivers/iio/adc/hx711.c | 106 ++++++++++++++++++++++++++++++++++++++++-------- 2 files changed, 90 insertions(+), 18 deletions(-)