Re: [PATCH v1] staging: fbtft: fb_st7789v: Initialize the Display

From: Dan Carpenter
Date: Thu Apr 09 2020 - 06:22:22 EST


On Thu, Apr 09, 2020 at 11:25:32AM +0200, Oliver Graute wrote:
> From: Oliver Graute <oliver.graute@xxxxxxxxxxxxxxxxx>
>
> Set Gamma Values and Register Values for the HSD20_IPS
>
> Signed-off-by: Oliver Graute <oliver.graute@xxxxxxxxxxxxxxxxx>
> ---
> drivers/staging/fbtft/fb_st7789v.c | 12 ++++++------
> 1 file changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/staging/fbtft/fb_st7789v.c b/drivers/staging/fbtft/fb_st7789v.c
> index 84c5af2dc9a0..b0aa96b703a8 100644
> --- a/drivers/staging/fbtft/fb_st7789v.c
> +++ b/drivers/staging/fbtft/fb_st7789v.c
> @@ -17,8 +17,8 @@
> #define DRVNAME "fb_st7789v"
>
> #define DEFAULT_GAMMA \
> - "70 2C 2E 15 10 09 48 33 53 0B 19 18 20 25\n" \
> - "70 2C 2E 15 10 09 48 33 53 0B 19 18 20 25"
> + "D0 05 0A 09 08 05 2E 44 45 0F 17 16 2B 33\n" \
> + "D0 05 0A 09 08 05 2E 43 45 0F 16 16 2B 33"

How do you know this won't break someone else's setup?

>
> /**
> * enum st7789v_command - ST7789V display controller commands
> @@ -83,13 +83,13 @@ static int init_display(struct fbtft_par *par)
> /* set pixel format to RGB-565 */
> write_reg(par, MIPI_DCS_SET_PIXEL_FORMAT, MIPI_DCS_PIXEL_FMT_16BIT);
>
> - write_reg(par, PORCTRL, 0x08, 0x08, 0x00, 0x22, 0x22);
> + write_reg(par, PORCTRL, 0x05, 0x05, 0x00, 0x33, 0x33);

Without knowing anything at all about this driver, it feels like this
should be:

if (new_hardware)
write_reg(par, PORCTRL, 0x05, 0x05, 0x00, 0x33, 0x33);
else
write_reg(par, PORCTRL, 0x08, 0x08, 0x00, 0x22, 0x22);

Same comment for the rest of the patch.

regards,
dan carpenter