On Wed, Apr 24, 2013 at 02:58:02PM +0100, Richard Hughes wrote:
> At the moment we're only extracting interesting strings. We have to be quite
> careful parsing the EDID data, as vendors like to do insane things.
>
> The original EDID parsing code was written by me for gnome-color-manager.
> ---
> src/compositor-drm.c | 149
> +++++++++++++++++++++++++++++++++++++++++++++++++++
> src/compositor.h | 2 +-
> 2 files changed, 150 insertions(+), 1 deletion(-)
Looks good, thanks.
Kristian
> diff --git a/src/compositor-drm.c b/src/compositor-drm.c
> index da1ba79..c8016cd 100644
> --- a/src/compositor-drm.c
> +++ b/src/compositor-drm.c
> @@ -25,6 +25,7 @@
>
> #include <errno.h>
> #include <stdlib.h>
> +#include <ctype.h>
> #include <string.h>
> #include <fcntl.h>
> #include <unistd.h>
> @@ -131,6 +132,13 @@ struct drm_fb {
> void *map;
> };
>
> +struct drm_edid {
> + char eisa_id[13];
> + char monitor_name[13];
> + char pnp_id[5];
> + char serial_number[13];
> +};
> +
> struct drm_output {
> struct weston_output base;
>
> @@ -139,6 +147,7 @@ struct drm_output {
> int pipe;
> uint32_t connector_id;
> drmModeCrtcPtr original_crtc;
> + struct drm_edid edid;
>
> int vblank_pending;
> int page_flip_pending;
> @@ -1486,6 +1495,143 @@ drm_output_fini_pixman(struct drm_output *output)
> }
> }
>
> +static void
> +edid_parse_string(const uint8_t *data, char text[])
> +{
> + int i;
> + int replaced = 0;
> +
> + /* this is always 12 bytes, but we can't guarantee it's null
> + * terminated or not junk. */
> + strncpy(text, (const char *) data, 12);
> +
> + /* remove insane chars */
> + for (i = 0; text[i] != '\0'; i++) {
> + if (text[i] == '\n' ||
> + text[i] == '\r') {
> + text[i] = '\0';
> + break;
> + }
> + }
> +
> + /* ensure string is printable */
> + for (i = 0; text[i] != '\0'; i++) {
> + if (!isprint(text[i])) {
> + text[i] = '-';
> + replaced++;
> + }
> + }
> +
> + /* if the string is random junk, ignore the string */
> + if (replaced > 4)
> + text[0] = '\0';
> +}
> +
> +#define EDID_DESCRIPTOR_ALPHANUMERIC_DATA_STRING 0xfe
> +#define EDID_DESCRIPTOR_DISPLAY_PRODUCT_NAME 0xfc
> +#define EDID_DESCRIPTOR_DISPLAY_PRODUCT_SERIAL_NUMBER 0xff
> +#define EDID_OFFSET_DATA_BLOCKS 0x36
> +#define EDID_OFFSET_LAST_BLOCK 0x6c
> +#define EDID_OFFSET_PNPID 0x08
> +#define EDID_OFFSET_SERIAL 0x0c
> +
> +static int
> +edid_parse(struct drm_edid *edid, const uint8_t *data, size_t length)
> +{
> + int i;
> + uint32_t serial_number;
> +
> + /* check header */
> + if (length < 128)
> + return -1;
> + if (data[0] != 0x00 || data[1] != 0xff)
> + return -1;
> +
> + /* decode the PNP ID from three 5 bit words packed into 2 bytes
> + * /--08--\/--09--\
> + * 7654321076543210
> + * |\---/\---/\---/
> + * R C1 C2 C3 */
> + edid->pnp_id[0] = 'A' + ((data[EDID_OFFSET_PNPID + 0] & 0x7c) / 4) - 1;
> + edid->pnp_id[1] = 'A' + ((data[EDID_OFFSET_PNPID + 0] & 0x3) * 8) +
> ((data[EDID_OFFSET_PNPID + 1] & 0xe0) / 32) - 1;
> + edid->pnp_id[2] = 'A' + (data[EDID_OFFSET_PNPID + 1] & 0x1f) - 1;
> + edid->pnp_id[3] = '\0';
> +
> + /* maybe there isn't a ASCII serial number descriptor, so use this
> instead */
> + serial_number = (uint32_t) data[EDID_OFFSET_SERIAL + 0];
> + serial_number += (uint32_t) data[EDID_OFFSET_SERIAL + 1] * 0x100;
> + serial_number += (uint32_t) data[EDID_OFFSET_SERIAL + 2] * 0x10000;
> + serial_number += (uint32_t) data[EDID_OFFSET_SERIAL + 3] * 0x1000000;
> + if (serial_number > 0)
> + sprintf(edid->serial_number, "%lu", (unsigned long)
> serial_number);
> +
> + /* parse EDID data */
> + for (i = EDID_OFFSET_DATA_BLOCKS;
> + i <= EDID_OFFSET_LAST_BLOCK;
> + i += 18) {
> + /* ignore pixel clock data */
> + if (data[i] != 0)
> + continue;
> + if (data[i+2] != 0)
> + continue;
> +
> + /* any useful blocks? */
> + if (data[i+3] == EDID_DESCRIPTOR_DISPLAY_PRODUCT_NAME) {
> + edid_parse_string(&data[i+5],
> + edid->monitor_name);
> + } else if (data[i+3] ==
> EDID_DESCRIPTOR_DISPLAY_PRODUCT_SERIAL_NUMBER) {
> + edid_parse_string(&data[i+5],
> + edid->serial_number);
> + } else if (data[i+3] ==
> EDID_DESCRIPTOR_ALPHANUMERIC_DATA_STRING) {
> + edid_parse_string(&data[i+5],
> + edid->eisa_id);
> + }
> + }
> + return 0;
> +}
> +
> +static void
> +find_and_parse_output_edid(struct drm_compositor *ec,
> + struct drm_output *output,
> + drmModeConnector *connector)
> +{
> + drmModePropertyBlobPtr edid_blob = NULL;
> + drmModePropertyPtr property;
> + int i;
> + int rc;
> +
> + for (i = 0; i < connector->count_props && !edid_blob; i++) {
> + property = drmModeGetProperty(ec->drm.fd, connector->props[i]);
> + if (!property)
> + continue;
> + if ((property->flags & DRM_MODE_PROP_BLOB) &&
> + !strcmp(property->name, "EDID")) {
> + edid_blob = drmModeGetPropertyBlob(ec->drm.fd,
> +
> connector->prop_values[i]);
> + }
> + drmModeFreeProperty(property);
> + }
> + if (!edid_blob)
> + return;
> +
> + rc = edid_parse(&output->edid,
> + edid_blob->data,
> + edid_blob->length);
> + if (!rc) {
> + weston_log("EDID data '%s', '%s', '%s'\n",
> + output->edid.pnp_id,
> + output->edid.monitor_name,
> + output->edid.serial_number);
> + if (output->edid.pnp_id[0] != '\0')
> + output->base.make = output->edid.pnp_id;
> + if (output->edid.monitor_name[0] != '\0')
> + output->base.model = output->edid.monitor_name;
> + if (output->edid.serial_number[0] != '\0')
> + output->base.serial_number = output->edid.serial_number;
> + }
> + drmModeFreePropertyBlob(edid_blob);
> +}
> +
> static int
> create_output_for_connector(struct drm_compositor *ec,
> drmModeRes *resources,
> @@ -1517,6 +1663,7 @@ create_output_for_connector(struct drm_compositor *ec,
> output->base.subpixel = drm_subpixel_to_wayland(connector->subpixel);
> output->base.make = "unknown";
> output->base.model = "unknown";
> + output->base.serial_number = "unknown";
> wl_list_init(&output->base.mode_list);
>
> if (connector->connector_type < ARRAY_LENGTH(connector_type_names))
> @@ -1642,6 +1789,8 @@ create_output_for_connector(struct drm_compositor *ec,
>
> wl_list_insert(ec->base.output_list.prev, &output->base.link);
>
> + find_and_parse_output_edid(ec, output, connector);
> +
> output->base.origin = output->base.current;
> output->base.start_repaint_loop = drm_output_start_repaint_loop;
> output->base.repaint = drm_output_repaint;
> diff --git a/src/compositor.h b/src/compositor.h
> index 1e999a6..eb8ad82 100644
> --- a/src/compositor.h
> +++ b/src/compositor.h
> @@ -178,7 +178,7 @@ struct weston_output {
> uint32_t frame_time;
> int disable_planes;
>
> - char *make, *model;
> + char *make, *model, *serial_number;
> uint32_t subpixel;
> uint32_t transform;
>
> --
> 1.8.2
>
> _______________________________________________
> wayland-devel mailing list
> wayland-devel@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/wayland-devel
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