diff --git a/drivers/iio/adc/max1027.c b/drivers/iio/adc/max1027.c index 63652a64e5a8..4d996fb09d7d 100644 --- a/drivers/iio/adc/max1027.c +++ b/drivers/iio/adc/max1027.c @@ -173,18 +173,53 @@ static const struct iio_chan_spec max1231_channels[] = { MAX1X31_CHANNELS(12), }; +/* + * These devices are able to scan from 0 to N, N being the highest voltage + * channel requested by the user. The temperature can be included or not, + * but cannot be retrieved alone. Based on the below + * ->available_scan_masks, the core will select the most appropriate + * ->active_scan_mask and the "minimum" number of channels will be + * scanned and pushed to the buffers. + * + * For example, if the user wants channels 1, 4 and 5, all channels from + * 0 to 5 will be scanned and pushed to the IIO buffers. The core will then + * filter out the unneeded samples based on the ->active_scan_mask that has + * been selected and only channels 1, 4 and 5 will be available to the user + * in the shared buffer. + */ +#define MAX1X27_SCAN_MASK_TEMP BIT(0) + +#define MAX1X27_SCAN_MASKS(temp) \ + GENMASK(1, 1 - (temp)), GENMASK(2, 1 - (temp)), \ + GENMASK(3, 1 - (temp)), GENMASK(4, 1 - (temp)), \ + GENMASK(5, 1 - (temp)), GENMASK(6, 1 - (temp)), \ + GENMASK(7, 1 - (temp)), GENMASK(8, 1 - (temp)) + +#define MAX1X29_SCAN_MASKS(temp) \ + MAX1X27_SCAN_MASKS(temp), \ + GENMASK(9, 1 - (temp)), GENMASK(10, 1 - (temp)), \ + GENMASK(11, 1 - (temp)), GENMASK(12, 1 - (temp)) + +#define MAX1X31_SCAN_MASKS(temp) \ + MAX1X29_SCAN_MASKS(temp), \ + GENMASK(13, 1 - (temp)), GENMASK(14, 1 - (temp)), \ + GENMASK(15, 1 - (temp)), GENMASK(16, 1 - (temp)) + static const unsigned long max1027_available_scan_masks[] = { - 0x000001ff, + MAX1X27_SCAN_MASKS(0), + MAX1X27_SCAN_MASKS(1), 0x00000000, }; static const unsigned long max1029_available_scan_masks[] = { - 0x00001fff, + MAX1X29_SCAN_MASKS(0), + MAX1X29_SCAN_MASKS(1), 0x00000000, }; static const unsigned long max1031_available_scan_masks[] = { - 0x0001ffff, + MAX1X31_SCAN_MASKS(0), + MAX1X31_SCAN_MASKS(1), 0x00000000, }; @@ -369,9 +404,15 @@ static int max1027_set_trigger_state(struct iio_trigger *trig, bool state) if (ret < 0) return ret; - /* Scan from 0 to max */ - st->reg = MAX1027_CONV_REG | MAX1027_CHAN(0) | - MAX1027_SCAN_N_M | MAX1027_TEMP; + /* + * Scan from chan 0 to the highest requested channel. + * Include temperature on demand. + */ + st->reg = MAX1027_CONV_REG | MAX1027_SCAN_0_N; + st->reg |= MAX1027_CHAN(fls(*indio_dev->active_scan_mask) - 2); + if (*indio_dev->active_scan_mask & MAX1X27_SCAN_MASK_TEMP) + st->reg |= MAX1027_TEMP; + ret = spi_write(st->spi, &st->reg, 1); if (ret < 0) return ret; @@ -392,9 +433,14 @@ static irqreturn_t max1027_trigger_handler(int irq, void *private) struct iio_poll_func *pf = private; struct iio_dev *indio_dev = pf->indio_dev; struct max1027_state *st = iio_priv(indio_dev); + unsigned int scanned_chans; + + scanned_chans = fls(*indio_dev->active_scan_mask) - 1; + if (*indio_dev->active_scan_mask & MAX1X27_SCAN_MASK_TEMP) + scanned_chans++; /* fill buffer with all channel */ - spi_read(st->spi, st->buffer, indio_dev->masklength * 2); + spi_read(st->spi, st->buffer, scanned_chans * 2); iio_push_to_buffers(indio_dev, st->buffer);