Re: [PATCH v5 08/10] iio: accel: adxl345: initialize FIFO delay value for SPI

Jonathan Cameron
2024-12-08T16:16:17Z

On Thu, 5 Dec 2024 17:13:41 +0000
Lothar Rubusch <l.rubusch@gmail.com> wrote:

> Add the possibility to delay FIFO access when SPI is used. According to
> the datasheet this is needed for the adxl345. When initialization
> happens over SPI the need for delay is to be signalized, and the delay
> will be used.
>
> Signed-off-by: Lothar Rubusch <l.rubusch@gmail.com>
Hi Lothar,

1 trivial comment below.

Jonathan
> diff --git a/drivers/iio/accel/adxl345_spi.c b/drivers/iio/accel/adxl345_spi.c
> index 61fd9a6f5fc..9829d5d3d43 100644
> --- a/drivers/iio/accel/adxl345_spi.c
> +++ b/drivers/iio/accel/adxl345_spi.c
> @@ -12,6 +12,7 @@
> #include "adxl345.h"
>
> #define ADXL345_MAX_SPI_FREQ_HZ 5000000
> +#define ADXL345_MAX_FREQ_NO_FIFO_DELAY 1500000
>
> static const struct regmap_config adxl345_spi_regmap_config = {
> .reg_bits = 8,
> @@ -28,6 +29,7 @@ static int adxl345_spi_setup(struct device *dev, struct regmap *regmap)
> static int adxl345_spi_probe(struct spi_device *spi)
> {
> struct regmap *regmap;
> + bool needs_delay;
>
> /* Bail out if max_speed_hz exceeds 5 MHz */
> if (spi->max_speed_hz > ADXL345_MAX_SPI_FREQ_HZ)
> @@ -38,10 +40,11 @@ static int adxl345_spi_probe(struct spi_device *spi)
> if (IS_ERR(regmap))
> return dev_err_probe(&spi->dev, PTR_ERR(regmap), "Error initializing regmap\n");
>
> + needs_delay = (spi->max_speed_hz > ADXL345_MAX_FREQ_NO_FIFO_DELAY);

Excess brackets. I'd drop them.

> if (spi->mode & SPI_3WIRE)
> - return adxl345_core_probe(&spi->dev, regmap, adxl345_spi_setup);
> + return adxl345_core_probe(&spi->dev, regmap, needs_delay, adxl345_spi_setup);
> else
> - return adxl345_core_probe(&spi->dev, regmap, NULL);
> + return adxl345_core_probe(&spi->dev, regmap, needs_delay, NULL);
> }
>
> static const struct adxl345_chip_info adxl345_spi_info = {