[PATCH 08/11] fbdev: Handle video= parameter in video/cmdline.c
Thomas Zimmermann
tzimmermann at suse.de
Fri Feb 10 00:55:06 AEDT 2023
Handle the command-line parameter video= in video/cmdline.c. Implement
the fbdev helper fb_get_options() on top. Will allows to handle the
kernel parameter in DRM without fbdev dependencies.
Note that __video_get_options() has the meaning of its return value
inverted compared to fb_get_options(). The new helper returns true if
the adapter has been enabled, and false otherwise.
There is the ofonly parameter, which disables output for non-OF-based
framebuffers. It is only for offb and looks like a workaround. The actual
purpose it not clear to me. Use 'video=off' or 'nomodeset' instead.
Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
---
drivers/gpu/drm/Kconfig | 2 +-
drivers/video/Kconfig | 3 +
drivers/video/Makefile | 1 +
drivers/video/cmdline.c | 133 ++++++++++++++++++++++++++
drivers/video/fbdev/Kconfig | 5 +-
drivers/video/fbdev/core/Makefile | 3 +-
drivers/video/fbdev/core/fb_cmdline.c | 93 +++---------------
include/video/cmdline.h | 20 ++++
8 files changed, 172 insertions(+), 88 deletions(-)
create mode 100644 drivers/video/cmdline.c
create mode 100644 include/video/cmdline.h
diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
index dc0f94f02a82..81c8a99c744a 100644
--- a/drivers/gpu/drm/Kconfig
+++ b/drivers/gpu/drm/Kconfig
@@ -10,13 +10,13 @@ menuconfig DRM
depends on (AGP || AGP=n) && !EMULATED_CMPXCHG && HAS_DMA
select DRM_PANEL_ORIENTATION_QUIRKS
select HDMI
- select FB_CMDLINE
select I2C
select DMA_SHARED_BUFFER
select SYNC_FILE
# gallium uses SYS_kcmp for os_same_file_description() to de-duplicate
# device and dmabuf fd. Let's make sure that is available for our userspace.
select KCMP
+ select VIDEO_CMDLINE
select VIDEO_NOMODESET
help
Kernel-level support for the Direct Rendering Infrastructure (DRI)
diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig
index 6d2fde6c5d11..bf05363d8906 100644
--- a/drivers/video/Kconfig
+++ b/drivers/video/Kconfig
@@ -11,6 +11,9 @@ config APERTURE_HELPERS
Support tracking and hand-over of aperture ownership. Required
by graphics drivers for firmware-provided framebuffers.
+config VIDEO_CMDLINE
+ bool
+
config VIDEO_NOMODESET
bool
default n
diff --git a/drivers/video/Makefile b/drivers/video/Makefile
index a50eb528ed3c..831c9fa57a6c 100644
--- a/drivers/video/Makefile
+++ b/drivers/video/Makefile
@@ -2,6 +2,7 @@
obj-$(CONFIG_APERTURE_HELPERS) += aperture.o
obj-$(CONFIG_VGASTATE) += vgastate.o
+obj-$(CONFIG_VIDEO_CMDLINE) += cmdline.o
obj-$(CONFIG_VIDEO_NOMODESET) += nomodeset.o
obj-$(CONFIG_HDMI) += hdmi.o
diff --git a/drivers/video/cmdline.c b/drivers/video/cmdline.c
new file mode 100644
index 000000000000..d3d257489c3d
--- /dev/null
+++ b/drivers/video/cmdline.c
@@ -0,0 +1,133 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Based on the fbdev code in drivers/video/fbdev/core/fb_cmdline:
+ *
+ * Copyright (C) 2014 Intel Corp
+ * Copyright (C) 1994 Martin Schaller
+ *
+ * 2001 - Documented with DocBook
+ * - Brad Douglas <brad at neruo.com>
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file COPYING in the main directory of this archive
+ * for more details.
+ *
+ * Authors:
+ * Daniel Vetter <daniel.vetter at ffwll.ch>
+ */
+
+#include <linux/fb.h> /* for FB_MAX */
+#include <linux/init.h>
+
+#include <video/cmdline.h>
+
+/*
+ * FB_MAX is the maximum number of framebuffer devices and also
+ * the maximum number of video= parameters. Although not directly
+ * related to each other, it makes sense to keep it that way.
+ */
+static const char *video_options[FB_MAX] __read_mostly;
+static const char *video_option __read_mostly;
+static int video_of_only __read_mostly;
+
+static const char *__video_get_option_string(const char *name)
+{
+ const char *options = NULL;
+ size_t name_len = 0;
+
+ if (name)
+ name_len = strlen(name);
+
+ if (name_len) {
+ unsigned int i;
+ const char *opt;
+
+ for (i = 0; i < ARRAY_SIZE(video_options); ++i) {
+ if (!video_options[i])
+ continue;
+ if (video_options[i][0] == '\0')
+ continue;
+ opt = video_options[i];
+ if (!strncmp(opt, name, name_len) && opt[name_len] == ':')
+ options = opt + name_len + 1;
+ }
+ }
+
+ /* No match, return global options */
+ if (!options)
+ options = video_option;
+
+ return options;
+}
+
+/**
+ * video_get_options - get kernel boot parameters
+ * @name: name of the output as it would appear in the boot parameter
+ * line (video=<name>:<options>)
+ *
+ * Looks up the video= options for the given name. Names are connector
+ * names with DRM, or driver names with fbdev. If no video option for
+ * the name has been specified, the function returns the global video=
+ * setting. A @name of NULL always returns the global video setting.
+ *
+ * Returns:
+ * The string of video options for the given name, or NULL if no video
+ * option has been specified.
+ */
+const char *video_get_options(const char *name)
+{
+ return __video_get_option_string(name);
+}
+EXPORT_SYMBOL(video_get_options);
+
+bool __video_get_options(const char *name, const char **options, bool is_of)
+{
+ bool enabled = true;
+ const char *opt = NULL;
+
+ if (video_of_only && !is_of)
+ enabled = false;
+
+ opt = __video_get_option_string(name);
+
+ if (options)
+ *options = opt;
+
+ return enabled;
+}
+EXPORT_SYMBOL(__video_get_options);
+
+/*
+ * Process command line options for video adapters. This function is
+ * a __setup and __init function. It only stores the options. Drivers
+ * have to call video_get_options() as necessary.
+ */
+static int __init video_setup(char *options)
+{
+ if (!options || !*options)
+ goto out;
+
+ if (!strncmp(options, "ofonly", 6)) {
+ video_of_only = true;
+ goto out;
+ }
+
+ if (strchr(options, ':')) {
+ /* named */
+ size_t i;
+
+ for (i = 0; i < ARRAY_SIZE(video_options); i++) {
+ if (!video_options[i]) {
+ video_options[i] = options;
+ break;
+ }
+ }
+ } else {
+ /* global */
+ video_option = options;
+ }
+
+out:
+ return 1;
+}
+__setup("video=", video_setup);
diff --git a/drivers/video/fbdev/Kconfig b/drivers/video/fbdev/Kconfig
index b2bed599e6c6..3623c1c0d34d 100644
--- a/drivers/video/fbdev/Kconfig
+++ b/drivers/video/fbdev/Kconfig
@@ -3,16 +3,13 @@
# fbdev configuration
#
-config FB_CMDLINE
- bool
-
config FB_NOTIFY
bool
menuconfig FB
tristate "Support for frame buffer devices"
- select FB_CMDLINE
select FB_NOTIFY
+ select VIDEO_CMDLINE
help
The frame buffer device provides an abstraction for the graphics
hardware. It represents the frame buffer of some video hardware and
diff --git a/drivers/video/fbdev/core/Makefile b/drivers/video/fbdev/core/Makefile
index 26cbc965497c..08fabce76b74 100644
--- a/drivers/video/fbdev/core/Makefile
+++ b/drivers/video/fbdev/core/Makefile
@@ -1,9 +1,8 @@
# SPDX-License-Identifier: GPL-2.0
-obj-$(CONFIG_FB_CMDLINE) += fb_cmdline.o
obj-$(CONFIG_FB_NOTIFY) += fb_notify.o
obj-$(CONFIG_FB) += fb.o
fb-y := fbmem.o fbmon.o fbcmap.o fbsysfs.o \
- modedb.o fbcvt.o
+ modedb.o fbcvt.o fb_cmdline.o
fb-$(CONFIG_FB_DEFERRED_IO) += fb_defio.o
ifeq ($(CONFIG_FRAMEBUFFER_CONSOLE),y)
diff --git a/drivers/video/fbdev/core/fb_cmdline.c b/drivers/video/fbdev/core/fb_cmdline.c
index f811c7b679e1..4d1634c492ec 100644
--- a/drivers/video/fbdev/core/fb_cmdline.c
+++ b/drivers/video/fbdev/core/fb_cmdline.c
@@ -14,42 +14,12 @@
* Authors:
* Daniel Vetter <daniel.vetter at ffwll.ch>
*/
-#include <linux/init.h>
-#include <linux/fb.h>
-
-static char *video_options[FB_MAX] __read_mostly;
-static const char *fb_mode_option __read_mostly;
-static int ofonly __read_mostly;
-
-static const char *__fb_get_options(const char *name)
-{
- const char *options = NULL;
- size_t name_len = 0;
-
- if (name)
- name_len = strlen(name);
- if (name_len) {
- unsigned int i;
- const char *opt;
-
- for (i = 0; i < ARRAY_SIZE(video_options); ++i) {
- if (!video_options[i])
- continue;
- if (video_options[i][0] == '\0')
- continue;
- opt = video_options[i];
- if (!strncmp(opt, name, name_len) && opt[name_len] == ':')
- options = opt + name_len + 1;
- }
- }
+#include <linux/export.h>
+#include <linux/fb.h>
+#include <linux/string.h>
- /* No match, return global options */
- if (!options)
- options = fb_mode_option;
-
- return options;
-}
+#include <video/cmdline.h>
/**
* fb_get_options - get kernel boot parameters
@@ -65,17 +35,18 @@ static const char *__fb_get_options(const char *name)
*/
int fb_get_options(const char *name, char **option)
{
- int retval = 0;
- const char *options;
+ const char *options = NULL;
+ bool is_of = false;
+ bool enabled;
- if (name && ofonly && strncmp(name, "offb", 4))
- retval = 1;
+ if (name)
+ is_of = strncmp(name, "offb", 4);
- options = __fb_get_options(name);
+ enabled = __video_get_options(name, &options, is_of);
if (options) {
if (!strncmp(options, "off", 3))
- retval = 1;
+ enabled = false;
}
if (option) {
@@ -85,46 +56,6 @@ int fb_get_options(const char *name, char **option)
*option = NULL;
}
- return retval;
+ return enabled ? 0 : 1; // 0 on success, 1 otherwise
}
EXPORT_SYMBOL(fb_get_options);
-
-/**
- * video_setup - process command line options
- * @options: string of options
- *
- * Process command line options for frame buffer subsystem.
- *
- * NOTE: This function is a __setup and __init function.
- * It only stores the options. Drivers have to call
- * fb_get_options() as necessary.
- */
-static int __init video_setup(char *options)
-{
- if (!options || !*options)
- goto out;
-
- if (!strncmp(options, "ofonly", 6)) {
- ofonly = 1;
- goto out;
- }
-
- if (strchr(options, ':')) {
- /* named */
- int i;
-
- for (i = 0; i < FB_MAX; i++) {
- if (video_options[i] == NULL) {
- video_options[i] = options;
- break;
- }
- }
- } else {
- /* global */
- fb_mode_option = options;
- }
-
-out:
- return 1;
-}
-__setup("video=", video_setup);
diff --git a/include/video/cmdline.h b/include/video/cmdline.h
new file mode 100644
index 000000000000..26b80cdaef79
--- /dev/null
+++ b/include/video/cmdline.h
@@ -0,0 +1,20 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef VIDEO_CMDLINE_H
+#define VIDEO_CMDLINE_H
+
+#include <linux/types.h>
+
+#if defined(CONFIG_VIDEO_CMDLINE)
+const char *video_get_options(const char *name);
+
+/* exported for compatibility with fbdev; don't use in new code */
+bool __video_get_options(const char *name, const char **option, bool is_of);
+#else
+static inline const char *video_get_options(const char *name)
+{
+ return NULL;
+}
+#endif
+
+#endif
--
2.39.1
More information about the Linuxppc-dev
mailing list