[PATCH] drm/omap: sharp ls037v7dw01: restore optional GPIOs

[Tony Lindgren]

* Russell King <rmk+kernel at armlinux.org.uk> [181207 21:24]:
> The binding document for this device says that all GPIOs are optional,
> but the driver fails to bind on OMAP3 LDP, reporting:
> 
> panel-sharp-ls037v7dw01: probe of display failed with error -2
> 
> Unfortunately, commit ca8c67dafdb7 ("fbdev: omap2: improve usage of
> gpiod API") removed the -ENOENT handling without converting the
> gpiod function to use the optional variant, causing all GPIOs to become
> mandatory.
> 
> Since the LDP hard-wires some of the panel control signals, there are
> no GPIOs that could be specified in DT to satisfy this.
> 
> Switch the driver to use the devm_gpiod_get_index_optional() rather
> than devm_gpiod_get_index() to conform to its binding documentation.
> 
> Fixes: ca8c67dafdb7 ("fbdev: omap2: improve usage of gpiod API")
> Signed-off-by: Russell King <rmk+kernel at armlinux.org.uk>

Acked-by: Tony Lindgren <tony at atomide.com>