[PATCH v2 4/9] drm/panel: Add driver for the LG Philips LB035Q02 panel

[Noralf Trønnes]

Sam,

Den 11.08.2019 01.10, skrev Laurent Pinchart:
> This panel is used on the Gumstix Overo Palo35.
> 
> The code is based on the omapdrm-specific panel-lgphilips-lb035q02
> driver.
> 
> Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> Reviewed-by: Sam Ravnborg <sam at ravnborg.org>
> ---

<snip>

> diff --git a/drivers/gpu/drm/panel/panel-lg-lb035q02.c b/drivers/gpu/drm/panel/panel-lg-lb035q02.c

<snip>

> +static int lb035q02_write(struct lb035q02_device *lcd, u16 reg, u16 val)
> +{
> +	struct spi_message msg;
> +	struct spi_transfer index_xfer = {
> +		.len		= 3,
> +		.cs_change	= 1,
> +	};
> +	struct spi_transfer value_xfer = {
> +		.len		= 3,
> +	};
> +	u8	buffer[16];
> +
> +	spi_message_init(&msg);
> +
> +	/* register index */
> +	buffer[0] = 0x70;
> +	buffer[1] = 0x00;
> +	buffer[2] = reg & 0x7f;
> +	index_xfer.tx_buf = buffer;
> +	spi_message_add_tail(&index_xfer, &msg);
> +
> +	/* register value */
> +	buffer[4] = 0x72;
> +	buffer[5] = val >> 8;
> +	buffer[6] = val;
> +	value_xfer.tx_buf = buffer + 4;
> +	spi_message_add_tail(&value_xfer, &msg);
> +
> +	return spi_sync(lcd->spi, &msg);
> +}

Just a note to Sam:
This is the same spi protocol that the ili9325 controller on the hy28b
panel uses.

I remembered that I have experimented with a regmap implementation:
https://github.com/notro/tinydrm/blob/master/tinydrm-ili9325.c#L191

Noralf.