On Fri, 9 Nov 2018 13:06:24 +0530
Nishad Kamdar <nishadkamdar@xxxxxxxxx> wrote:
> AD7818 does not support busy_pin functionality as per datasheet.
> Hence drop busy_pin when AD7818 is used.
>
> Signed-off-by: Nishad Kamdar <nishadkamdar@xxxxxxxxx>
Applied to the togreg branch of iio.git and pushed out as testing
for the autobuilders to play with it.
A slight concern that I can't immediately find an answer to,
is whether we should be waiting a short while for the ad7818 given
we can't wait on the gpio? We can add this in a follow up patch
if it is necessary.
Thanks,
Jonathan
> ---
> drivers/staging/iio/adc/ad7816.c | 35 ++++++++++++++++++++++----------
> 1 file changed, 24 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/staging/iio/adc/ad7816.c b/drivers/staging/iio/adc/ad7816.c
> index 12c4e0ab4713..3cda5cd09365 100644
> --- a/drivers/staging/iio/adc/ad7816.c
> +++ b/drivers/staging/iio/adc/ad7816.c
> @@ -43,6 +43,7 @@
> */
>
> struct ad7816_chip_info {
> + kernel_ulong_t id;
> struct spi_device *spi_dev;
> struct gpio_desc *rdwr_pin;
> struct gpio_desc *convert_pin;
> @@ -52,6 +53,12 @@ struct ad7816_chip_info {
> u8 mode;
> };
>
> +enum ad7816_type {
> + ID_AD7816,
> + ID_AD7817,
> + ID_AD7818,
> +};
> +
> /*
> * ad7816 data access by SPI
> */
> @@ -78,8 +85,10 @@ static int ad7816_spi_read(struct ad7816_chip_info *chip, u16 *data)
> gpiod_set_value(chip->convert_pin, 1);
> }
>
> - while (gpiod_get_value(chip->busy_pin))
> - cpu_relax();
> + if (chip->id == ID_AD7816 || chip->id == ID_AD7817) {
> + while (gpiod_get_value(chip->busy_pin))
> + cpu_relax();
> + }
>
> gpiod_set_value(chip->rdwr_pin, 0);
> gpiod_set_value(chip->rdwr_pin, 1);
> @@ -359,6 +368,7 @@ static int ad7816_probe(struct spi_device *spi_dev)
> for (i = 0; i <= AD7816_CS_MAX; i++)
> chip->oti_data[i] = 203;
>
> + chip->id = spi_get_device_id(spi_dev)->driver_data;
> chip->rdwr_pin = devm_gpiod_get(&spi_dev->dev, "rdwr", GPIOD_IN);
> if (IS_ERR(chip->rdwr_pin)) {
> ret = PTR_ERR(chip->rdwr_pin);
> @@ -373,12 +383,15 @@ static int ad7816_probe(struct spi_device *spi_dev)
> ret);
> return ret;
> }
> - chip->busy_pin = devm_gpiod_get(&spi_dev->dev, "busy", GPIOD_IN);
> - if (IS_ERR(chip->busy_pin)) {
> - ret = PTR_ERR(chip->busy_pin);
> - dev_err(&spi_dev->dev, "Failed to request busy GPIO: %d\n",
> - ret);
> - return ret;
> + if (chip->id == ID_AD7816 || chip->id == ID_AD7817) {
> + chip->busy_pin = devm_gpiod_get(&spi_dev->dev, "busy",
> + GPIOD_IN);
> + if (IS_ERR(chip->busy_pin)) {
> + ret = PTR_ERR(chip->busy_pin);
> + dev_err(&spi_dev->dev, "Failed to request busy GPIO: %d\n",
> + ret);
> + return ret;
> + }
> }
>
> indio_dev->name = spi_get_device_id(spi_dev)->name;
> @@ -409,9 +422,9 @@ static int ad7816_probe(struct spi_device *spi_dev)
> }
>
> static const struct spi_device_id ad7816_id[] = {
> - { "ad7816", 0 },
> - { "ad7817", 0 },
> - { "ad7818", 0 },
> + { "ad7816", ID_AD7816 },
> + { "ad7817", ID_AD7817 },
> + { "ad7818", ID_AD7818 },
> {}
> };
>
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