diff options
Diffstat (limited to 'drivers/iio/adc/hx711.c')
| -rw-r--r-- | drivers/iio/adc/hx711.c | 134 |
1 files changed, 104 insertions, 30 deletions
diff --git a/drivers/iio/adc/hx711.c b/drivers/iio/adc/hx711.c index d10b9f13d557..9430b54121e0 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 + 64-bit timestamp + */ + u32 buffer[4]; }; static int hx711_cycle(struct hx711_data *hx711_data) @@ -145,15 +153,16 @@ static int hx711_wait_for_ready(struct hx711_data *hx711_data) int i, val; /* - * a maximum reset cycle time of 56 ms was measured. - * we round it up to 100 ms + * in some rare cases the reset takes quite a long time + * especially when the channel is changed. + * Allow up to one second for it */ for (i = 0; i < 100; i++) { val = gpiod_get_value(hx711_data->gpiod_dout); if (!val) break; - /* sleep at least 1 ms */ - msleep(1); + /* sleep at least 10 ms */ + msleep(10); } if (val) return -EIO; @@ -195,9 +204,7 @@ static int hx711_reset(struct hx711_data *hx711_data) * after a dummy read we need to wait vor readiness * for not mixing gain pulses with the clock */ - ret = hx711_wait_for_ready(hx711_data); - if (ret) - return ret; + val = hx711_wait_for_ready(hx711_data); } return val; @@ -236,34 +243,40 @@ 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)) { + 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, 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 +352,36 @@ 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, 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, struct device_attribute *attr, char *buf) @@ -387,6 +430,13 @@ 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, + .endianness = IIO_CPU, + }, }, { .type = IIO_VOLTAGE, @@ -394,7 +444,15 @@ 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, + .endianness = IIO_CPU, + }, }, + IIO_CHAN_SOFT_TIMESTAMP(2), }; static int hx711_probe(struct platform_device *pdev) @@ -459,10 +517,9 @@ static int hx711_probe(struct platform_device *pdev) * 1 LSB = (AVDD * 100) / GAIN / 1678 [10^-9 mV] */ ret = regulator_get_voltage(hx711_data->reg_avdd); - if (ret < 0) { - regulator_disable(hx711_data->reg_avdd); - return ret; - } + if (ret < 0) + goto error_regulator; + /* we need 10^-9 mV */ ret *= 100; @@ -482,12 +539,27 @@ static int hx711_probe(struct platform_device *pdev) indio_dev->channels = 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); if (ret < 0) { 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; } @@ -501,6 +573,8 @@ static int hx711_remove(struct platform_device *pdev) iio_device_unregister(indio_dev); + iio_triggered_buffer_cleanup(indio_dev); + regulator_disable(hx711_data->reg_avdd); return 0; |