On 7/20/23 12:26, Otto Pflüger wrote:
> Displays that are connected to the same SPI bus may share the D/C GPIO.
> Use GPIOD_FLAGS_BIT_NONEXCLUSIVE to allow access to the same GPIO for
> multiple panel-mipi-dbi instances. Exclusive access to the GPIO during
> transfers is ensured by the locking in drm_mipi_dbi.c.
>
> Signed-off-by: Otto Pflüger <otto.pflue...@abscue.de>
> ---
> drivers/gpu/drm/tiny/panel-mipi-dbi.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/tiny/panel-mipi-dbi.c
> b/drivers/gpu/drm/tiny/panel-mipi-dbi.c
> index eb9f13f18a02..e616e3890043 100644
> --- a/drivers/gpu/drm/tiny/panel-mipi-dbi.c
> +++ b/drivers/gpu/drm/tiny/panel-mipi-dbi.c
> @@ -307,7 +307,8 @@ static int panel_mipi_dbi_spi_probe(struct spi_device
> *spi)
> if (IS_ERR(dbi->reset))
> return dev_err_probe(dev, PTR_ERR(dbi->reset), "Failed to get
> GPIO 'reset'\n");
>
> - dc = devm_gpiod_get_optional(dev, "dc", GPIOD_OUT_LOW);
Please add a comment here that sharing only works when on the same SPI bus.
> + dc = devm_gpiod_get_optional(dev, "dc",
> + GPIOD_OUT_LOW |
> GPIOD_FLAGS_BIT_NONEXCLUSIVE);
I'd prefer this to be on one line, the 80 column limit has been upped to
a 100 now.
Noralf.
> if (IS_ERR(dc))
> return dev_err_probe(dev, PTR_ERR(dc), "Failed to get GPIO
> 'dc'\n");
>
