From 6c7bc1d27bb227da89aa7e1be71d01b92719551d Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Leonard=20G=C3=B6hrs?= Date: Fri, 7 Jul 2023 08:36:35 +0200 Subject: [PATCH] iio: adc: ti-lmp92064: add buffering support MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Reviewed-by: Nuno Sa Link: https://lore.kernel.org/r/20230707063635.1496437-1-l.goehrs@pengutronix.de Signed-off-by: Jonathan Cameron --- drivers/iio/adc/ti-lmp92064.c | 53 +++++++++++++++++++++++++++++++++++ 1 file changed, 53 insertions(+) diff --git a/drivers/iio/adc/ti-lmp92064.c b/drivers/iio/adc/ti-lmp92064.c index c30ed824924f..84ba5c4a0eea 100644 --- a/drivers/iio/adc/ti-lmp92064.c +++ b/drivers/iio/adc/ti-lmp92064.c @@ -16,7 +16,10 @@ #include #include +#include #include +#include +#include #define TI_LMP92064_REG_CONFIG_A 0x0000 #define TI_LMP92064_REG_CONFIG_B 0x0001 @@ -91,6 +94,12 @@ 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 = TI_LMP92064_CHAN_INC, + .scan_type = { + .sign = 'u', + .realbits = 12, + .storagebits = 16, + }, .datasheet_name = "INC", }, { @@ -98,8 +107,20 @@ 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 = TI_LMP92064_CHAN_INV, + .scan_type = { + .sign = 'u', + .realbits = 12, + .storagebits = 16, + }, .datasheet_name = "INV", }, + IIO_CHAN_SOFT_TIMESTAMP(2), +}; + +static const unsigned long lmp92064_scan_masks[] = { + BIT(TI_LMP92064_CHAN_INC) | BIT(TI_LMP92064_CHAN_INV), + 0 }; static int lmp92064_read_meas(struct lmp92064_adc_priv *priv, u16 *res) @@ -171,6 +192,32 @@ 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); + struct { + u16 values[2]; + int64_t timestamp __aligned(8); + } data; + int ret; + + memset(&data, 0, sizeof(data)); + + ret = lmp92064_read_meas(priv, data.values); + if (ret) + goto err; + + iio_push_to_buffers_with_timestamp(indio_dev, &data, + iio_get_time_ns(indio_dev)); + +err: + iio_trigger_notify_done(indio_dev->trig); + + return IRQ_HANDLED; +} + static int lmp92064_reset(struct lmp92064_adc_priv *priv, struct gpio_desc *gpio_reset) { @@ -301,6 +348,12 @@ static int lmp92064_adc_probe(struct spi_device *spi) indio_dev->channels = lmp92064_adc_channels; indio_dev->num_channels = ARRAY_SIZE(lmp92064_adc_channels); indio_dev->info = &lmp92064_adc_info; + indio_dev->available_scan_masks = lmp92064_scan_masks; + + 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); }