Enable buffered reading of samples from the LMP92064 ADC. The main benefit of this change is being able to read out current and voltage measurements in a single transfer, allowing instantaneous power measurements. Reads into the buffer can be triggered by any software triggers, e.g. the iio-trig-hrtimer: $ mkdir /sys/kernel/config/iio/triggers/hrtimer/my-trigger $ cat /sys/bus/iio/devices/iio\:device3/name lmp92064 $ iio_readdev -t my-trigger -b 16 iio:device3 | hexdump WARNING: High-speed mode not enabled 0000000 0000 0176 0101 0001 5507 abd5 7645 1768 0000010 0000 016d 0101 0001 ee1e ac6b 7645 1768 ... Signed-off-by: Leonard Göhrs <l.goehrs@xxxxxxxxxxxxxx> --- drivers/iio/adc/ti-lmp92064.c | 54 +++++++++++++++++++++++++++++++++++ 1 file changed, 54 insertions(+) diff --git a/drivers/iio/adc/ti-lmp92064.c b/drivers/iio/adc/ti-lmp92064.c index c30ed824924f3..03765c4057dda 100644 --- a/drivers/iio/adc/ti-lmp92064.c +++ b/drivers/iio/adc/ti-lmp92064.c @@ -16,7 +16,10 @@ #include <linux/spi/spi.h> #include <linux/iio/iio.h> +#include <linux/iio/buffer.h> #include <linux/iio/driver.h> +#include <linux/iio/triggered_buffer.h> +#include <linux/iio/trigger_consumer.h> #define TI_LMP92064_REG_CONFIG_A 0x0000 #define TI_LMP92064_REG_CONFIG_B 0x0001 @@ -91,6 +94,13 @@ static const struct iio_chan_spec lmp92064_adc_channels[] = { .address = TI_LMP92064_CHAN_INC, .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE), + .scan_index = 0, + .scan_type = { + .sign = 'u', + .realbits = 12, + .storagebits = 16, + .shift = 0, + }, .datasheet_name = "INC", }, { @@ -98,8 +108,16 @@ static const struct iio_chan_spec lmp92064_adc_channels[] = { .address = TI_LMP92064_CHAN_INV, .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE), + .scan_index = 1, + .scan_type = { + .sign = 'u', + .realbits = 12, + .storagebits = 16, + .shift = 0, + }, .datasheet_name = "INV", }, + IIO_CHAN_SOFT_TIMESTAMP(2), }; static int lmp92064_read_meas(struct lmp92064_adc_priv *priv, u16 *res) @@ -171,6 +189,37 @@ static int lmp92064_read_raw(struct iio_dev *indio_dev, } } +static irqreturn_t lmp92064_trigger_handler(int irq, void *p) +{ + struct iio_poll_func *pf = p; + struct iio_dev *indio_dev = pf->indio_dev; + struct lmp92064_adc_priv *priv = iio_priv(indio_dev); + int i = 0, j, ret; + u16 raw[2]; + u16 *data; + + ret = lmp92064_read_meas(priv, raw); + if (ret < 0) + goto done; + + data = kmalloc(indio_dev->scan_bytes, GFP_KERNEL); + if (!data) + goto done; + + for_each_set_bit(j, indio_dev->active_scan_mask, indio_dev->masklength) + data[i++] = raw[j]; + + iio_push_to_buffers_with_timestamp(indio_dev, data, + iio_get_time_ns(indio_dev)); + + kfree(data); + +done: + iio_trigger_notify_done(indio_dev->trig); + + return IRQ_HANDLED; +} + static int lmp92064_reset(struct lmp92064_adc_priv *priv, struct gpio_desc *gpio_reset) { @@ -302,6 +351,11 @@ static int lmp92064_adc_probe(struct spi_device *spi) indio_dev->num_channels = ARRAY_SIZE(lmp92064_adc_channels); indio_dev->info = &lmp92064_adc_info; + ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL, + lmp92064_trigger_handler, NULL); + if (ret) + return dev_err_probe(dev, ret, "Failed to setup buffered read\n"); + return devm_iio_device_register(dev, indio_dev); } base-commit: 9561de3a55bed6bdd44a12820ba81ec416e705a7 -- 2.39.2