Re: [PATCH v3 5/5] drm/panel: Add ilitek ili9341 driver

On Thu, May 14, 2020 at 12:22 PM dillon min [off-list ref] wrote:

quoted

quoted

+       /* Gamma */
+       mipi_dbi_command(dbi, ILI9341_3GAMMA_EN, 0x00);
+       mipi_dbi_command(dbi, MIPI_DCS_SET_GAMMA_CURVE, 0x01);
+       mipi_dbi_command(dbi, ILI9341_PGAMMA,
+                        0x0f, 0x31, 0x2b, 0x0c, 0x0e, 0x08, 0x4e, 0xf1,
+                        0x37, 0x07, 0x10, 0x03, 0x0e, 0x09, 0x00);
+       mipi_dbi_command(dbi, ILI9341_NGAMMA,
+                        0x00, 0x0e, 0x14, 0x03, 0x11, 0x07, 0x31, 0xc1,
+                        0x48, 0x08, 0x0f, 0x0c, 0x31, 0x36, 0x0f);

It seems to be copies of the stuff above, but why is there a different
gamma if you use DBI?

for dbi interface, currently i just copy the code from tiny/ili9341.c.
as so many boards use this driver now, like raspberry pi, etc
i'm afraid it's will not work after modification. so, just leave the
original code there.

OK if you move it to ili9341_config it will be clear which panels
need this gamma and which panels need another gamma.

I think there should be one ili9341_config for the new st,*
variant and one for the old DBI variant.

anther question:
is there any panel driver have dbi & dpi or dpi & dsi supported? which
i mean support
two different panel interface in one driver.
thanks

Usually you split the driver in three files becuase a driver can
only list one initcall, and also it makes it modularized.

There is nothing in-tree but look at my branch here:
https://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-nomadik.git/log/?h=ux500-skomer-v5.7-rc1

You see how I split up the s6e63m0 driver in one SPI part
and one DSI part:
https://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-nomadik.git/commit/?h=ux500-skomer-v5.7-rc1&id=6c0e1fb5df5fa8fa857dee65f6c0f54d06d158a7
https://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-nomadik.git/commit/?h=ux500-skomer-v5.7-rc1&id=cfbf562cc709b53b62f5fbc7fedf176ffa17b088

The overall idea should work the same with DBI.

Yours,
Linus Walleij

Yours,
Linus Walleij