Mode detection currently reports the modes listed in fb_info::modelist.
The list is either build from EDID information or, more often, a list of
previously set modes. A later update to the mode detection could also
take into account the modes in fb_monspecs::modedb or test pre-defined
VESA modes.
Signed-off-by: Thomas Zimmermann <tzimmermann@xxxxxxx>
---
drivers/gpu/drm/fbdevdrm/fbdevdrm_modeset.c | 163 +++++++++++++++++++-
1 file changed, 162 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/fbdevdrm/fbdevdrm_modeset.c b/drivers/gpu/drm/fbdevdrm/fbdevdrm_modeset.c
index 87f56ec76edf..e89eca4b58df 100644
--- a/drivers/gpu/drm/fbdevdrm/fbdevdrm_modeset.c
+++ b/drivers/gpu/drm/fbdevdrm/fbdevdrm_modeset.c
@@ -21,9 +21,16 @@
#include <drm/drm_print.h>
#include <drm/drm_probe_helper.h>
#include <linux/fb.h>
+#include "fbdevdrm_device.h"
#include "fbdevdrm_modes.h"
#include "fbdevdrm_primary.h"
+static struct fbdevdrm_modeset* fbdevdrm_modeset_of_connector(
+ struct drm_connector *connector)
+{
+ return container_of(connector, struct fbdevdrm_modeset, connector);
+}
+
static struct fbdevdrm_modeset* fbdevdrm_modeset_of_crtc(
struct drm_crtc *crtc)
{
@@ -353,11 +360,130 @@ static const struct drm_encoder_funcs fbdevdrm_encoder_funcs = {
* Connector
*/
-static int connector_helper_get_modes(struct drm_connector *connector)
+static int update_display_info(struct drm_display_info *info, struct fb_info *fb_info)
+{
+ int num_pixel;
+
+ if (fb_info->fix.type != FB_TYPE_PACKED_PIXELS)
+ return -EINVAL; /* rule out text mode, etc. */
+
+ if (fb_info->fix.id[0]) {
+ strncpy(info->name, fb_info->fix.id, sizeof(info->name) - 1);
+ info->name[sizeof(info->name) - 1] = '\0';
+ } else {
+ memset(info->name, '\0', sizeof(info->name));
+ }
+
+ info->width_mm = fb_info->var.width;
+ info->height_mm = fb_info->var.height;
+ info->pixel_clock = PICOS2KHZ(fb_info->var.pixclock);
+
+ num_pixel = 0;
+ if (fb_info->var.red.length)
+ ++num_pixel;
+ if (fb_info->var.green.length)
+ ++num_pixel;
+ if (fb_info->var.blue.length)
+ ++num_pixel;
+ if (fb_info->var.transp.length)
+ ++num_pixel;
+
+ if (num_pixel)
+ info->bpc = fb_info->var.bits_per_pixel;
+ else
+ info->bpc = 0;
+
+ info->subpixel_order = SubPixelUnknown;
+ info->color_formats = DRM_COLOR_FORMAT_RGB444;
+ info->bus_formats = &info->color_formats;
+ info->num_bus_formats = 1;
+ info->bus_flags = 0;
+ info->max_tmds_clock = 0;
+ info->dvi_dual = false;
+ info->has_hdmi_infoframe = false;
+ info->edid_hdmi_dc_modes = 0;
+ info->cea_rev = 0;
+ memset(&info->hdmi, 0, sizeof(info->hdmi));
+ info->non_desktop = 0;
+
+ return 0;
+}
+
+static int drm_mode_probed_add_from_fb_videomode(
+ struct drm_connector *connector, const struct fb_videomode *fb_mode,
+ struct fb_info *fb_info)
{
+ struct drm_display_mode *mode;
+
+ mode = drm_mode_create_from_fb_videomode(connector->dev, fb_mode);
+ if (!mode)
+ return -ENOMEM;
+
+ mode->width_mm = fb_info->var.width;
+ mode->height_mm = fb_info->var.height;
+
+ drm_mode_probed_add(connector, mode);
+
+ /* update connector properties from display mode */
+ if (mode->flags & DRM_MODE_FLAG_INTERLACE)
+ connector->interlace_allowed = true;
+ if (mode->flags & DRM_MODE_FLAG_DBLSCAN)
+ connector->doublescan_allowed = true;
+ if (mode->flags & DRM_MODE_FLAG_3D_MASK)
+ connector->stereo_allowed = true;
+
return 0;
}
+static int connector_helper_get_modes(struct drm_connector *connector)
+{
+ struct fbdevdrm_modeset *modeset;
+ struct list_head *pos;
+ int ret, num_modes = 0;
+
+ modeset = fbdevdrm_modeset_of_connector(connector);
+
+ ret = update_display_info(&connector->display_info, modeset->fb_info);
+ if (ret)
+ return 0;
+
+ /* update connector properties from video modes */
+ connector->interlace_allowed = 0;
+ connector->doublescan_allowed = 0;
+ connector->stereo_allowed = 0;
+
+ if (!num_modes && modeset->fb_info->mode) {
+ ret = drm_mode_probed_add_from_fb_videomode(
+ connector, modeset->fb_info->mode, modeset->fb_info);
+ if (!ret)
+ ++num_modes;
+ }
+
+ if (!num_modes) {
+
+ /* DRM backporting notes: we go through all modes in the
+ * fb_info's mode list and convert each to a DRM modes. If
+ * you convert an fbdev driver to DRM, replace this code
+ * with an actual hardware query. This will usually involve
+ * reading the monitor EDID via DDC.
+ */
+
+ list_for_each(pos, &modeset->fb_info->modelist) {
+ const struct fb_modelist *modelist =
+ container_of(pos, struct fb_modelist, list);
+
+ ret = drm_mode_probed_add_from_fb_videomode(
+ connector, &modelist->mode,
+ modeset->fb_info);
+ if (ret < 0)
+ continue;
+ ++num_modes;
+ }
+ }
+
+ return num_modes;
+}
+
static int connector_helper_detect_ctx(struct drm_connector *connector,
struct drm_modeset_acquire_ctx *ctx,
bool force)
@@ -368,6 +494,21 @@ static int connector_helper_detect_ctx(struct drm_connector *connector,
static enum drm_mode_status connector_helper_mode_valid(
struct drm_connector *connector, struct drm_display_mode *mode)
{
+ struct fb_var_screeninfo fb_var;
+ int ret;
+ struct fbdevdrm_modeset *modeset = fbdevdrm_modeset_of_connector(connector);
+
+ /* fb_validate_mode() requires fb_info->monspecs to contain valid
+ * data. Skip the test if the maximum clock looks bogus. */
+ if (!modeset->fb_info->monspecs.dclkmax)
+ return MODE_OK;
+
+ fbdevdrm_init_fb_var_screeninfo_from_mode(&fb_var, mode);
+
+ ret = fb_validate_mode(&fb_var, modeset->fb_info);
+ if (ret < 0)
+ return MODE_BAD;
+
return MODE_OK;
}
@@ -444,6 +585,26 @@ static const struct drm_connector_funcs fbdevdrm_connector_funcs = {
static enum drm_mode_status mode_config_mode_valid(
struct drm_device *dev, const struct drm_display_mode *mode)
{
+ /* TODO: maybe detect maximum depth */
+ static const unsigned int max_bpp = 4; /* 32-bit depth */
+
+ size_t vram_size_2, fb_size;
+ struct fbdevdrm_device *fdev = fbdevdrm_device_of_dev(dev);
+
+ /* DRM porting note: The atomic mode-setting framework requires
+ * two framebuffers to be present in VRAM during page flips. This
+ * is a problem for modes that require buffers larger than half
+ * the VRAM size. This can happen on older graphics cards with less
+ * than 16 MiB of VRAM. There's no point in reporting such modes,
+ * so we sort them out. If you're porting an fbdevdriver to DRM, you
+ * may want to keep this policy if the device has limited VRAM.
+ */
+ vram_size_2 = fdev->ttm.vram_size / 2;
+
+ fb_size = mode->hdisplay * mode->vdisplay * max_bpp;
+ if (fb_size > vram_size_2)
+ return MODE_MEM;
+
return MODE_OK;
}
--
2.21.0
