While working on another series[1] I ran into issues where my SPI controller would fail to handle 14-bit and 16-bit SPI messages. This addresses that issue and adds support for selecting a different voltage reference source from the devicetree. V1 was base on a series[2] that seems to not have made it all the way, and was tested on an ad7689. [1] https://patchwork.kernel.org/project/linux-iio/list/?series=511545 [2] https://patchwork.kernel.org/project/linux-iio/list/?series=116971&state=%2A&archive=both Changes since v4: - fix premature deletion of define - use separate be16 buffer for 8-bit transfers - switch to devm_regulator_get_optional() - fix vref setup - apply Reviewed-by Changes since v3: - use cpu_to_be16 and be16_to_cpu instead of manual conversion - use pointers to channel structures instead of copies - switch to generic device firmware property API - use standard unit suffix names (mV to microvolt) - switch to devm_iio_device_register() for additional cleanup Changes since v2: - add comments to ambiguous register names - fix be16 definition of the adc buffer - fix BPW logic - rework vref support - support per channel vref selection - infer reference select value based on DT parameters - update dt-binding Changes since v1: - add default case in read/write size cases - drop of_node change as the core already takes care of it - check dt user input in probe - move description at the top of dt-binding definition - drop AllOf block in dt-binding Thanks for your time, Liam Liam Beguin (5): iio: adc: ad7949: define and use bitfield names iio: adc: ad7949: fix spi messages on non 14-bit controllers iio: adc: ad7949: add support for internal vref dt-bindings: iio: adc: ad7949: add per channel reference iio: adc: ad7949: use devm managed functions .../bindings/iio/adc/adi,ad7949.yaml | 69 ++++- drivers/iio/adc/ad7949.c | 281 ++++++++++++++---- 2 files changed, 291 insertions(+), 59 deletions(-) Range-diff against v4: 1: 8760b368f971 ! 1: a5c211185661 iio: adc: ad7949: define and use bitfield names @@ drivers/iio/adc/ad7949.c #define AD7949_MASK_TOTAL GENMASK(13, 0) -#define AD7949_OFFSET_CHANNEL_SEL 7 -#define AD7949_CFG_READ_BACK 0x1 --#define AD7949_CFG_REG_SIZE_BITS 14 -+ + #define AD7949_CFG_REG_SIZE_BITS 14 + +/* CFG: Configuration Update */ +#define AD7949_CFG_BIT_OVERWRITE BIT(13) + @@ drivers/iio/adc/ad7949.c + +/* RB: Read back the CFG register */ +#define AD7949_CFG_BIT_RBN BIT(0) - ++ enum { ID_AD7949 = 0, + ID_AD7682, @@ drivers/iio/adc/ad7949.c: static int ad7949_spi_read_channel(struct ad7949_adc_chip *ad7949_adc, int *val, */ for (i = 0; i < 2; i++) { 2: 7b1484f2fc4c ! 2: df2f6df8f3d5 iio: adc: ad7949: fix spi messages on non 14-bit controllers @@ Commit message Signed-off-by: Liam Beguin <lvb@xxxxxxxxxx> ## drivers/iio/adc/ad7949.c ## +@@ + #include <linux/bitfield.h> + + #define AD7949_MASK_TOTAL GENMASK(13, 0) +-#define AD7949_CFG_REG_SIZE_BITS 14 + + /* CFG: Configuration Update */ + #define AD7949_CFG_BIT_OVERWRITE BIT(13) @@ drivers/iio/adc/ad7949.c: static const struct ad7949_adc_spec ad7949_adc_spec[] = { * @indio_dev: reference to iio structure * @spi: reference to spi structure @@ drivers/iio/adc/ad7949.c: static const struct ad7949_adc_spec ad7949_adc_spec[] * @cfg: copy of the configuration register * @current_channel: current channel in use * @buffer: buffer to send / receive data to / from device ++ * @buf8b: be16 buffer to exchange data with the device in 8-bit transfers + */ + struct ad7949_adc_chip { + struct mutex lock; @@ drivers/iio/adc/ad7949.c: struct ad7949_adc_chip { struct iio_dev *indio_dev; struct spi_device *spi; @@ drivers/iio/adc/ad7949.c: struct ad7949_adc_chip { u16 cfg; unsigned int current_channel; u16 buffer ____cacheline_aligned; -@@ drivers/iio/adc/ad7949.c: static int ad7949_spi_write_cfg(struct ad7949_adc_chip *ad7949_adc, u16 val, ++ __be16 buf8b; + }; + + static int ad7949_spi_write_cfg(struct ad7949_adc_chip *ad7949_adc, u16 val, u16 mask) { int ret; @@ drivers/iio/adc/ad7949.c: static int ad7949_spi_write_cfg(struct ad7949_adc_chip struct spi_message msg; struct spi_transfer tx[] = { { - .tx_buf = &ad7949_adc->buffer, +- .tx_buf = &ad7949_adc->buffer, .len = 2, - .bits_per_word = bits_per_word, + .bits_per_word = ad7949_adc->bits_per_word, }, }; -+ ad7949_adc->buffer = 0; ad7949_adc->cfg = (val & mask) | (ad7949_adc->cfg & ~mask); - ad7949_adc->buffer = ad7949_adc->cfg << shift; + + switch (ad7949_adc->bits_per_word) { + case 16: ++ tx[0].tx_buf = &ad7949_adc->buffer; + ad7949_adc->buffer = ad7949_adc->cfg << 2; + break; + case 14: ++ tx[0].tx_buf = &ad7949_adc->buffer; + ad7949_adc->buffer = ad7949_adc->cfg; + break; + case 8: + /* Here, type is big endian as it must be sent in two transfers */ -+ ad7949_adc->buffer = (u16)cpu_to_be16(ad7949_adc->cfg << 2); ++ tx[0].tx_buf = &ad7949_adc->buf8b; ++ ad7949_adc->buf8b = cpu_to_be16(ad7949_adc->cfg << 2); + break; + default: + dev_err(&ad7949_adc->indio_dev->dev, "unsupported BPW\n"); @@ drivers/iio/adc/ad7949.c: static int ad7949_spi_read_channel(struct ad7949_adc_c struct spi_message msg; struct spi_transfer tx[] = { { - .rx_buf = &ad7949_adc->buffer, +- .rx_buf = &ad7949_adc->buffer, .len = 2, - .bits_per_word = bits_per_word, + .bits_per_word = ad7949_adc->bits_per_word, }, }; ++ if (ad7949_adc->bits_per_word == 8) ++ tx[0].rx_buf = &ad7949_adc->buf8b; ++ else ++ tx[0].rx_buf = &ad7949_adc->buffer; ++ + /* + * 1: write CFG for sample N and read old data (sample N-2) + * 2: if CFG was not changed since sample N-1 then we'll get good data +@@ drivers/iio/adc/ad7949.c: static int ad7949_spi_read_channel(struct ad7949_adc_chip *ad7949_adc, int *val, + } + + /* 3: write something and read actual data */ +- ad7949_adc->buffer = 0; + spi_message_init_with_transfers(&msg, tx, 1); + ret = spi_sync(ad7949_adc->spi, &msg); + if (ret) @@ drivers/iio/adc/ad7949.c: static int ad7949_spi_read_channel(struct ad7949_adc_chip *ad7949_adc, int *val, ad7949_adc->current_channel = channel; @@ drivers/iio/adc/ad7949.c: static int ad7949_spi_read_channel(struct ad7949_adc_c + break; + case 8: + /* Here, type is big endian as data was sent in two transfers */ -+ *val = be16_to_cpu(ad7949_adc->buffer); ++ *val = be16_to_cpu(ad7949_adc->buf8b); + /* Shift-out padding bits */ + *val >>= 16 - ad7949_adc->resolution; + break; 3: 41c4ab9c5e19 ! 3: 8a33618a4f90 iio: adc: ad7949: add support for internal vref @@ drivers/iio/adc/ad7949.c: static int ad7949_spi_read_channel(struct ad7949_adc_c + struct ad7949_channel *ad7949_chan = &ad7949_adc->channels[channel]; struct spi_transfer tx[] = { { - .rx_buf = &ad7949_adc->buffer, + .len = 2, @@ drivers/iio/adc/ad7949.c: static int ad7949_spi_read_channel(struct ad7949_adc_chip *ad7949_adc, int *val, */ for (i = 0; i < 2; i++) { @@ drivers/iio/adc/ad7949.c: static int ad7949_spi_probe(struct spi_device *spi) - ad7949_adc->vref = devm_regulator_get(dev, "vref"); + /* Setup external voltage ref, buffered? */ -+ ad7949_adc->vref = devm_regulator_get(dev, "vrefin"); ++ ad7949_adc->vref = devm_regulator_get_optional(dev, "vrefin"); if (IS_ERR(ad7949_adc->vref)) { - dev_err(dev, "fail to request regulator\n"); - return PTR_ERR(ad7949_adc->vref); ++ ret = PTR_ERR(ad7949_adc->vref); ++ if (ret != -ENODEV) ++ return ret; + /* unbuffered? */ -+ ad7949_adc->vref = devm_regulator_get(dev, "vref"); ++ ad7949_adc->vref = devm_regulator_get_optional(dev, "vref"); + if (IS_ERR(ad7949_adc->vref)) { ++ ret = PTR_ERR(ad7949_adc->vref); ++ if (ret != -ENODEV) ++ return ret; + /* Internal then */ + mode = AD7949_CFG_VAL_REF_INT_4096; ++ } else { ++ mode = AD7949_CFG_VAL_REF_EXT_TEMP; + } -+ mode = AD7949_CFG_VAL_REF_EXT_TEMP; ++ } else { ++ mode = AD7949_CFG_VAL_REF_EXT_TEMP_BUF; } -+ mode = AD7949_CFG_VAL_REF_EXT_TEMP_BUF; - ret = regulator_enable(ad7949_adc->vref); - if (ret < 0) { 4: 9cb48acbd05b ! 4: 7612ff29db6b dt-bindings: iio: adc: ad7949: add per channel reference @@ Commit message calculation. Signed-off-by: Liam Beguin <lvb@xxxxxxxxxx> + Reviewed-by: Rob Herring <robh@xxxxxxxxxx> ## Documentation/devicetree/bindings/iio/adc/adi,ad7949.yaml ## @@ Documentation/devicetree/bindings/iio/adc/adi,ad7949.yaml: properties: 5: c48eb017058c = 5: 74ee82caba57 iio: adc: ad7949: use devm managed functions base-commit: 6cbb3aa0f9d5d23221df787cf36f74d3866fdb78 -- 2.32.0.452.g940fe202adcb
