drm: port the drm backend to the new init api

Preparing for libweston and for the separation of the code base into
libweston vs. weston the compositor, we must remove all uses
weston_config structures from the backends. We have decided that all
option and config input happens in the compositor (main.c), and
configuration is passed in for the backends as structs.

Most other backends have already converted, and this patch converts the
DRM-backend to the libweston-style init API.

The libweston-style init API includes a header for each backend (here
compositor-drm.h) defining the configuration interface. The compositor
(main.c) prepares a configuration struct to be passed through libweston
core to the backend during initialization.

A complication with the DRM-backend is that outputs can be hotplugged,
and their configuration needs to be fetched from the compositor
(main.c). For this, the config struct contains a callback member. The
output configuration API is subject to change later, this is just a
temporary API to get libweston forward.

As weston_compositor's user_data was not previously used for anything,
and the output configuration callback needs data, the user_data is set
to the 'config' pointer. This pointer is only used in
drm_configure_output() in main.c.

[Bryce: lots of stuff and rebasing]
Signed-off-by: Bryce Harrington <bryce@osg.samsung.com>
Reviewed-by: Quentin Glidic <sardemff7+git@sardemff7.net>
Acked-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
Tested-by: Benoit Gschwind <gschwind@gnu-log.net>
[Pekka: write commit message]
[Pekka: squash in "drm: Don't hang onto the backend config object
post-backend_init" from Bryce Harrington]
[Pekka: drop the compositor.h hunk]
[Pekka: do not #include inside extern "C"]
[Pekka: remove incorrect comment about weston_drm_backend_config
ownership.]
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>

1 files changed, 81 insertions, 3 deletions

diff --git a/src/main.c b/src/main.c
index 2a56555c..b6e989ff 100644
--- a/src/main.c
+++ b/src/main.c
@@ -47,6 +47,7 @@
 #include "git-version.h"
 #include "version.h"
 
+#include "compositor-drm.h"
 #include "compositor-headless.h"
 #include "compositor-rdp.h"
 #include "compositor-fbdev.h"
@@ -688,6 +689,83 @@ load_backend_new(struct weston_compositor *compositor, const char *backend,
 	return backend_init(compositor, NULL, NULL, NULL, config_base);
 }
 
+static enum weston_drm_backend_output_mode
+drm_configure_output(struct weston_compositor *c,
+		     bool use_current_mode,
+		     const char *name,
+		     struct weston_drm_backend_output_config *config)
+{
+	struct weston_config *wc = weston_compositor_get_user_data(c);
+	struct weston_config_section *section;
+	char *s;
+	int scale;
+	enum weston_drm_backend_output_mode mode =
+		WESTON_DRM_BACKEND_OUTPUT_PREFERRED;
+
+	section = weston_config_get_section(wc, "output", "name", name);
+	weston_config_section_get_string(section, "mode", &s, "preferred");
+	if (strcmp(s, "off") == 0) {
+		free(s);
+		return WESTON_DRM_BACKEND_OUTPUT_OFF;
+	}
+
+	if (use_current_mode || strcmp(s, "current") == 0) {
+		mode = WESTON_DRM_BACKEND_OUTPUT_CURRENT;
+	} else if (strcmp(s, "preferred") != 0) {
+		config->modeline = s;
+		s = NULL;
+	}
+	free(s);
+
+	weston_config_section_get_int(section, "scale", &scale, 1);
+	config->base.scale = scale >= 1 ? scale : 1;
+	weston_config_section_get_string(section, "transform", &s, "normal");
+	if (weston_parse_transform(s, &config->base.transform) < 0)
+		weston_log("Invalid transform \"%s\" for output %s\n",
+			   s, name);
+	free(s);
+
+	weston_config_section_get_string(section,
+					 "gbm-format", &config->gbm_format, NULL);
+	weston_config_section_get_string(section, "seat", &config->seat, "");
+	return mode;
+}
+
+static int
+load_drm_backend(struct weston_compositor *c, const char *backend,
+		 int *argc, char **argv, struct weston_config *wc)
+{
+	struct weston_drm_backend_config config = {{ 0, }};
+	struct weston_config_section *section;
+	int ret = 0;
+
+	const struct weston_option options[] = {
+		{ WESTON_OPTION_INTEGER, "connector", 0, &config.connector },
+		{ WESTON_OPTION_STRING, "seat", 0, &config.seat_id },
+		{ WESTON_OPTION_INTEGER, "tty", 0, &config.tty },
+		{ WESTON_OPTION_BOOLEAN, "current-mode", 0, &config.use_current_mode },
+		{ WESTON_OPTION_BOOLEAN, "use-pixman", 0, &config.use_pixman },
+	};
+
+	parse_options(options, ARRAY_LENGTH(options), argc, argv);
+
+	section = weston_config_get_section(wc, "core", NULL, NULL);
+	weston_config_section_get_string(section,
+					 "gbm-format", &config.gbm_format,
+					 NULL);
+
+	config.base.struct_version = WESTON_DRM_BACKEND_CONFIG_VERSION;
+	config.base.struct_size = sizeof(struct weston_drm_backend_config);
+	config.configure_output = drm_configure_output;
+
+	ret = load_backend_new(c, backend, &config.base);
+
+	free(config.gbm_format);
+	free(config.seat_id);
+
+	return ret;
+}
+
 static int
 load_headless_backend(struct weston_compositor *c, char const * backend,
 		      int *argc, char **argv, struct weston_config *wc)
@@ -959,11 +1037,11 @@ load_backend(struct weston_compositor *compositor, const char *backend,
 		return load_rdp_backend(compositor, backend, argc, argv, config);
 	else if (strstr(backend, "fbdev-backend.so"))
 		return load_fbdev_backend(compositor, backend, argc, argv, config);
+	else if (strstr(backend, "drm-backend.so"))
+		return load_drm_backend(compositor, backend, argc, argv, config);
 	else if (strstr(backend, "x11-backend.so"))
 		return load_x11_backend(compositor, backend, argc, argv, config);
 #if 0
-	else if (strstr(backend, "drm-backend.so"))
-		return load_drm_backend(compositor, backend, argc, argv, config);
 	else if (strstr(backend, "wayland-backend.so"))
 		return load_wayland_backend(compositor, backend, argc, argv, config);
 	else if (strstr(backend, "rpi-backend.so"))
@@ -1064,7 +1142,7 @@ int main(int argc, char *argv[])
 			backend = weston_choose_default_backend();
 	}
 
-	ec = weston_compositor_create(display, NULL);
+	ec = weston_compositor_create(display, config);
 	if (ec == NULL) {
 		weston_log("fatal: failed to create compositor\n");
 		goto out;