On Sun, 18 Jul 2021 at 08:31, Linus Walleij <linus.walleij@linaro.org> wrote:
Hi Dillon,
thanks for your patch!
On Fri, Jul 16, 2021 at 12:20 PM <dillon.minfei@gmail.com> wrote:
> From: Dillon Min <dillon.minfei@gmail.com>
>
> This driver combine tiny/ili9341.c mipi_dbi_interface driver
> with mipi_dpi_interface driver, can support ili9341 with serial
> mode or parallel rgb interface mode by register configuration.
>
> Signed-off-by: Dillon Min <dillon.minfei@gmail.com>
Nice!
> +config DRM_PANEL_ILITEK_ILI9341
> + tristate "Ilitek ILI9341 240x320 QVGA panels"
> + depends on OF && SPI
> + depends on DRM_KMS_HELPER
> + depends on DRM_KMS_CMA_HELPER
(...)
> +#include <drm/drm_gem_framebuffer_helper.h>
> +#include <drm/drm_gem_cma_helper.h>
> +#include <drm/drm_fb_helper.h>
> +#include <drm/drm_gem_atomic_helper.h>
> +#include <drm/drm_atomic_helper.h>
Hm now there is a (partial) KMS driver in the panel driver, kinda, sorta.
Is this the right split? I'm not the best with DRM infrastructure,
just asking.
I tried to remove one of these two headers, but got compile errors:
linux/drivers/
gpu/
drm/panel/panel-
ilitek-ili9341.c:719:3: error: implicit declaration of function 'drm_atomic_helper_shutdown' [-
Werror=implicit-function-declaration]
719 |
drm_atomic_helper_shutdown(
drm);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~
or
linux/drivers/
gpu/
drm/panel/panel-
ilitek-ili9341.c:562:16: error: 'drm_gem_simple_display_pipe_prepare_fb' undeclared here (not in a function)
562 | .prepare_
fb =
drm_gem_simple_display_pipe_prepare_
fb,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Actually, these two headers are merged from tiny/ili9341.c to support only-DBI interface, I'm
not sure whether the maintainers will ask me to remove (tiny/ili9341.c) code from this patch.
If so, I will remove these headers.
But, It's a little strange to support different interfaces from different drivers.
> +struct ili9341_config {
> + u32 max_spi_speed;
> + /** @mode: the drm display mode */
> + const struct drm_display_mode mode;
> + /* @ca: TODO: need comments for this register */
> + u8 ca[ILI9341_CA_LEN];
These are all in the datasheet but I guess you plan to add these
TODOs later. (It's fine I suppose, the driver is already very nice.)
Yes, I didn't get detailed information about these registers from this
panel datasheet, so leave TODOs here.
> + struct regulator *vcc;
Use the right name of the pin for the regulator. I guess this is actually
vci. I would implement all three regulators and get them as bulk.
See e.g. drivers/gpu/drm/panel/panel-samsung-s6e3ha2.c
for an example on how to get and enable several regulators
using bulk.
The regulator framework will provide dummy regulators if you
didn't define some of them so it is fine to just provide one or two.
Really appreciate your suggestion, will add to v2.
Yours,
Linus Walleij