Re: [PATCH v2 3/5] drm/modes: Allow to specify rotation and reflection on the commandline

Daniel Vetter
2019-04-15T16:39:49Z

On Thu, Apr 11, 2019 at 03:22:41PM +0200, Maxime Ripard wrote:
> Rotations and reflections setup are needed in some scenarios to initialise
> properly the initial framebuffer. Some drivers already had a bunch of
> quirks to deal with this, such as either a private kernel command line
> parameter (omapdss) or on the device tree (various panels).
>
> In order to accomodate this, let's create a video mode parameter to deal
> with the rotation and reflexion.
>
> Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
> ---
> drivers/gpu/drm/drm_fb_helper.c | 4 +-
> drivers/gpu/drm/drm_modes.c | 110 +++++++++++++++++++++++++++------
> include/drm/drm_connector.h | 1 +-
> 3 files changed, 95 insertions(+), 20 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
> index b3a5d79436ae..8781897559b2 100644
> --- a/drivers/gpu/drm/drm_fb_helper.c
> +++ b/drivers/gpu/drm/drm_fb_helper.c
> @@ -2521,6 +2521,7 @@ static void drm_setup_crtc_rotation(struct drm_fb_helper *fb_helper,
> struct drm_connector *connector)
> {
> struct drm_plane *plane = fb_crtc->mode_set.crtc->primary;
> + struct drm_cmdline_mode *mode = &connector->cmdline_mode;
> uint64_t valid_mask = 0;
> int i, rotation;
>
> @@ -2540,6 +2541,9 @@ static void drm_setup_crtc_rotation(struct drm_fb_helper *fb_helper,
> rotation = DRM_MODE_ROTATE_0;
> }
>
> + if (mode->rotation != DRM_MODE_ROTATE_0)
> + fb_crtc->rotation = mode->rotation;

Hm, kinda awkward that we have to tie all this to the fbdev helpers. But
that's already the case with the old stuff, so mea culpa I guess.

> +
> /*
> * TODO: support 90 / 270 degree hardware rotation,
> * depending on the hardware this may require the framebuffer
> diff --git a/drivers/gpu/drm/drm_modes.c b/drivers/gpu/drm/drm_modes.c
> index 9613c1a28487..ac8d70b92b62 100644
> --- a/drivers/gpu/drm/drm_modes.c
> +++ b/drivers/gpu/drm/drm_modes.c
> @@ -1531,6 +1531,71 @@ static int drm_mode_parse_cmdline_res_mode(const char *str, unsigned int length,
> return 0;
> }
>
> +static int drm_mode_parse_cmdline_options(char *str, size_t len,
> + struct drm_connector *connector,
> + struct drm_cmdline_mode *mode)
> +{
> + unsigned int rotation = 0;
> + char *sep = str;
> +
> + while ((sep = strchr(sep, ','))) {
> + char *delim, *option;
> +
> + option = sep + 1;
> + delim = strchr(option, '=');
> + if (!delim) {
> + delim = strchr(option, ',');
> +
> + if (!delim)
> + delim = str + len;
> + }
> +
> + if (!strncmp(option, "rotate", delim - option)) {
> + const char *value = delim + 1;
> + unsigned int deg;
> +
> + deg = simple_strtol(value, &sep, 10);
> +
> + /* Make sure we have parsed something */
> + if (sep == value)
> + return -EINVAL;
> +
> + switch (deg) {
> + case 0:
> + rotation |= DRM_MODE_ROTATE_0;
> + break;
> +
> + case 90:
> + rotation |= DRM_MODE_ROTATE_90;
> + break;
> +
> + case 180:
> + rotation |= DRM_MODE_ROTATE_180;
> + break;
> +
> + case 270:
> + rotation |= DRM_MODE_ROTATE_270;
> + break;
> +
> + default:
> + return -EINVAL;
> + }
> + } else if (!strncmp(option, "reflect_x", delim - option)) {
> + rotation |= DRM_MODE_REFLECT_X;
> + sep = delim;
> + } else if (!strncmp(option, "reflect_y", delim - option)) {
> + rotation |= DRM_MODE_REFLECT_Y;
> + sep = delim;
> + } else {
> + return -EINVAL;
> + }
> + }
> +
> + mode->rotation = rotation;
> +
> + return 0;
> +}
> +
> /**
> * drm_mode_parse_command_line_for_connector - parse command line modeline for connector
> * @mode_option: optional per connector mode option
> @@ -1558,9 +1623,10 @@ bool drm_mode_parse_command_line_for_connector(const char *mode_option,
> {
> const char *name;
> bool named_mode = false, parse_extras = false;
> - unsigned int bpp_off = 0, refresh_off = 0;
> + unsigned int bpp_off = 0, refresh_off = 0, options_off = 0;
> unsigned int mode_end = 0;
> char *bpp_ptr = NULL, *refresh_ptr = NULL, *extra_ptr = NULL;
> + char *options_ptr = NULL;
> char *bpp_end_ptr = NULL, *refresh_end_ptr = NULL;
> int ret;
>
> @@ -1601,13 +1667,18 @@ bool drm_mode_parse_command_line_for_connector(const char *mode_option,
> mode->refresh_specified = true;
> }
>
> + /* Locate the start of named options */
> + options_ptr = strchr(name, ',');
> + if (options_ptr)
> + options_off = options_ptr - name;
> +
> /* Locate the end of the name / resolution, and parse it */
> - if (bpp_ptr && refresh_ptr) {
> - mode_end = min(bpp_off, refresh_off);
> - } else if (bpp_ptr) {
> + if (bpp_ptr) {
> mode_end = bpp_off;
> } else if (refresh_ptr) {
> mode_end = refresh_off;
> + } else if (options_ptr) {
> + mode_end = options_off;
> } else {
> mode_end = strlen(name);
> parse_extras = true;
> @@ -1649,24 +1720,23 @@ bool drm_mode_parse_command_line_for_connector(const char *mode_option,
> else if (refresh_ptr)
> extra_ptr = refresh_end_ptr;
>
> - if (extra_ptr) {
> - if (!named_mode) {
> - int len = strlen(name) - (extra_ptr - name);
> + if (extra_ptr &&
> + extra_ptr != options_ptr) {
> + int len = strlen(name) - (extra_ptr - name);
>
> - ret = drm_mode_parse_cmdline_extra(extra_ptr, len,
> - connector, mode);
> - if (ret)
> - return false;
> - } else {
> - int remaining = strlen(name) - (extra_ptr - name);
> + ret = drm_mode_parse_cmdline_extra(extra_ptr, len,
> + connector, mode);
> + if (ret)
> + return false;
> + }
>
> - /*
> - * We still have characters to process, while
> - * we shouldn't have any
> - */
> - if (remaining > 0)
> - return false;
> - }
> + if (options_ptr) {
> + int len = strlen(name) - (options_ptr - name);
> +
> + ret = drm_mode_parse_cmdline_options(options_ptr, len,
> + connector, mode);
> + if (ret)
> + return false;
> }
>
> return true;
> diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
> index 06aa3b9cb920..dfe7f2304b35 100644
> --- a/include/drm/drm_connector.h
> +++ b/include/drm/drm_connector.h
> @@ -907,6 +907,7 @@ struct drm_cmdline_mode {
> bool interlace;
> bool cvt;
> bool margins;
> + unsigned int rotation;
> enum drm_connector_force force;

Kerneldoc for this would be neat.
-Daniel

> };
>
> --
> git-series 0.9.1
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--
Daniel Vetter
Software Engineer, Intel Corporation