[PATCH 03/11] Bring in dynamic videomode selection at runtime
Sascha Hauer
s.hauer at pengutronix.de
Fri Oct 22 13:41:09 EDT 2010
On Fri, Oct 22, 2010 at 06:53:17PM +0200, Juergen Beisert wrote:
> This patch mostly rewrites all parts of /drivers/video/fb.c. As it changes
> the API to the drivers, it must be done in one step to keep the repository
> bisectable. But to do it in one step makes the patches itself unreadable.
>
> So, I decided to do it in a few steps, only for the review. All patches marked
> with a "step n of m" should be merged, prior the final commit into the
> repository.
>
> This step brings in the required functions for dynamic videomode selection at
> runtime, but keep the old functions untouched (the new ones are commented out).
>
> This is patch 1 of 7 to keep the repository bisectable.
>
> Signed-off-by: Juergen Beisert <jbe at pengutronix.de>
> ---
> drivers/video/Kconfig | 23 +++++
> drivers/video/fb.c | 251 +++++++++++++++++++++++++++++++++++++++++++++++++
> include/fb.h | 40 ++++++++
> 3 files changed, 314 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig
> index 7a89a3f..e6ecfc8 100644
> --- a/drivers/video/Kconfig
> +++ b/drivers/video/Kconfig
> @@ -5,6 +5,29 @@ menuconfig VIDEO
>
> if VIDEO
>
> +comment "runtime options"
> +
> +config VIDEO_DELAY_ENABLING
> + bool "Delayed enabling"
> + help
> + Say 'y' here to delay enabling video output. This is useful to first
> + fill the framebuffer (splash screen for example) prior enabling the
> + video device.
> + This entry adds the "enable" parameter to the video device, to enable
> + or disable video output at runtime.
> +
> +config VIDEO_DELAY_INIT
> + bool "Delayed initialization"
> + select VIDEO_DELAY_ENABLING
> + help
> + If the platform supports more than one video mode say 'y' her to delay
> + the initialization of the video device until any kind of barebox's
> + shell code sets up the correct mode at runtime.
> + This entry adds the "mode" parameter to the video device, to setup
> + the desired videomode prior enabling it at runtime.
I think the framebuffers should *never* be activated by the setup code
and should be explicitely initialized by doing a 'fb0.enable=1' on the
command line. This way we have the most flexibility. We can enable
the framebuffer when we actually need it, we can draw a splash screen
before enabling it so that we do not have a black screen before we draw
an image. Also, the environment can decide to leave the framebuffer
disabled because the kernel will draw another screen a second later. If
necessary, the environemt can do a fb0.display="sharp-whatever" before
activating it. And we do not need any kconfig options for this.
Sascha
> +
> +comment "drivers"
> +
> config DRIVER_VIDEO_IMX
> bool "i.MX framebuffer driver"
> depends on ARCH_IMX1 || ARCH_IMX21 || ARCH_IMX25 || ARCH_IMX27
> diff --git a/drivers/video/fb.c b/drivers/video/fb.c
> index f9a425e..c2934f6 100644
> --- a/drivers/video/fb.c
> +++ b/drivers/video/fb.c
> @@ -1,3 +1,4 @@
> +#include <init.h>
> #include <common.h>
> #include <fb.h>
> #include <errno.h>
> @@ -5,6 +6,8 @@
> #include <getopt.h>
> #include <fcntl.h>
> #include <fs.h>
> +#include <malloc.h>
> +#include <xfuncs.h>
>
> static int fb_ioctl(struct cdev* cdev, int req, void *data)
> {
> @@ -57,6 +60,141 @@ static int fb_enable_set(struct device_d *dev, struct param_d *param,
> return 0;
> }
>
> +#if 0
> +#ifdef CONFIG_VIDEO_DELAY_INIT
> +static int fb_check_if_already_initialized(struct device_d *fb_dev)
> +{
> + struct cdev *cdev = fb_dev->priv;
> + struct fb_info *info = cdev->priv;
> +
> + if (info->active_mode != NULL) {
> + pr_err("Video mode '%s' is already set. Cannot change colour depth anymore.\n", info->active_mode->name);
> + return -EPERM;
> + }
> +
> + return 0;
> +}
> +
> +static int fb_cdepth_set(struct device_d *fb_dev, struct param_d *param, const char *val)
> +{
> + struct cdev *cdev = fb_dev->priv;
> + struct fb_info *info = cdev->priv;
> + unsigned cdepth;
> + int rc;
> +
> + rc = fb_check_if_already_initialized(fb_dev);
> + if (rc != 0)
> + return rc;
> +
> + cdepth = simple_strtoul(val, NULL, 0);
> + if (cdepth != 0)
> + info->bits_per_pixel = cdepth;
> + else
> + return -EINVAL;
> +
> + return dev_param_set_generic(fb_dev, param, val);
> +}
> +#endif
> +
> +#ifdef CONFIG_VIDEO_DELAY_ENABLING
> +static int fb_enable_set(struct device_d *fb_dev, struct param_d *param, const char *val)
> +{
> + struct cdev *cdev = fb_dev->priv;
> + struct fb_info *info = cdev->priv;
> + struct fb_host *host = fb_dev->platform_data;
> + int enable;
> + char *new;
> +
> + if (!val)
> + return dev_param_set_generic(fb_dev, param, NULL);
> +
> + enable = simple_strtoul(val, NULL, 0);
> +
> + if (info->enabled == !!enable)
> + return 0;
> +
> + if (enable) {
> + (host->fb_enable)(info);
> + new = "1";
> + } else {
> + (host->fb_disable)(info);
> + new = "0";
> + }
> +
> + info->enabled = !!enable;
> +
> + return dev_param_set_generic(fb_dev, param, new);
> +}
> +#endif
> +
> +static void fb_list_modes(struct fb_host *host)
> +{
> + unsigned u;
> +
> + if (host->mode_cnt == 0)
> + return;
> +
> + printf(" Supported video mode(s):\n");
> + for (u = 0; u < host->mode_cnt; u++)
> + printf(" '%s'\n", host->mode[u].name);
> +}
> +
> +static int fb_activate_mode(struct device_d *fb_dev, const struct fb_videomode *mode)
> +{
> + struct cdev *cdev = fb_dev->priv;
> + struct fb_info *info = cdev->priv;
> + struct fb_host *host = fb_dev->platform_data;
> + int rc;
> +
> + rc = (host->fb_mode)(info, mode);
> + if (rc != 0)
> + return rc;
> +
> + info->active_mode = mode;
> + /*
> + * At this point of time we know the remaining information we need
> + * for the cdev and fb_info structure.
> + */
> + cdev->size = fb_dev->size;
> + info->xres = mode->xres;
> + info->yres = mode->yres;
> +
> + return 0;
> +}
> +
> +#ifdef CONFIG_VIDEO_DELAY_INIT
> +static int fb_mode_set(struct device_d *fb_dev, struct param_d *param, const char *name)
> +{
> + struct fb_host *host = fb_dev->platform_data;
> + unsigned u;
> + int rc;
> +
> + pr_debug("%s called\n", __func__);
> +
> + rc = fb_check_if_already_initialized(fb_dev);
> + if (rc != 0)
> + return rc;
> +
> + /* Search for the requested video mode by name */
> + for (u = 0; u < host->mode_cnt; u++) {
> + if (!strcmp(host->mode[u].name, name))
> + break;
> + }
> + if (u >= host->mode_cnt) {
> + fb_list_modes(host); /* no mode with 'name' found */
> + return -ENODEV;
> + } else {
> + rc = fb_activate_mode(fb_dev, &host->mode[u]);
> + }
> +
> + if (rc == 0)
> + dev_param_set_generic(fb_dev, param, name);
> +
> + return rc;
> +}
> +#endif
> +#endif
> +
> static struct file_operations fb_ops = {
> .read = mem_read,
> .write = mem_write,
> @@ -65,6 +203,119 @@ static struct file_operations fb_ops = {
> .ioctl = fb_ioctl,
> };
>
> +#if 0
> +static int add_fb_parameter(struct device_d *fb_dev)
> +{
> +#ifdef CONFIG_VIDEO_DELAY_INIT
> + struct cdev *cdev = fb_dev->priv;
> + struct fb_info *info = cdev->priv;
> + char cd[10];
> +
> + /** @todo provide base address parameter for the user */
> +
> + dev_add_param(fb_dev, "cdepth", fb_cdepth_set, NULL, 0);
> + if (info->bits_per_pixel == 0) {
> + dev_set_param(fb_dev, "cdepth", "16");
> + info->bits_per_pixel = 16;
> + } else {
> + sprintf(cd, "%u", info->bits_per_pixel);
> + dev_set_param(fb_dev, "cdepth", cd);
> + }
> + dev_add_param(fb_dev, "mode", fb_mode_set, NULL, 0);
> + /* default is 'none' for delayed video mode setup */
> +#endif
> +#ifdef CONFIG_VIDEO_DELAY_ENABLING
> + dev_add_param(fb_dev, "enable", fb_enable_set, NULL, 0);
> + /* default is 'off' for delayed video output */
> +#endif
> + return 0;
> +}
> +
> +struct framebuffer_desc {
> + struct cdev cdev;
> + struct fb_info info;
> +};
> +
> +static int fb_probe(struct device_d *fb_dev)
> +{
> + int id = get_free_deviceid("fb");
> + struct cdev *cdev;
> + struct fb_info *info;
> + struct fb_host *host = fb_dev->platform_data;
> +
> + cdev = xzalloc(sizeof(struct framebuffer_desc));
> + info = (struct fb_info*)&cdev[1];
> +
> + fb_dev->priv = cdev; /* pointer forward */
> + cdev->dev = fb_dev; /* pointer backward */
> +
> + cdev->ops = &fb_ops;
> + cdev->name = asprintf("fb%d", id);
> +
> + cdev->size = fb_dev->size; /* use the default if any */
> + cdev->priv = info;
> +
> + info->host = host;
> + info->fb_dev = fb_dev;
> +
> + /* setup defaults */
> + if (host->bits_per_pixel != 0)
> + info->bits_per_pixel = host->bits_per_pixel;
> + else
> + info->bits_per_pixel = 16; /* means RGB565 */
> +
> + /* add params on demand */
> + add_fb_parameter(fb_dev);
> +
> + devfs_create(cdev);
> +#ifndef CONFIG_VIDEO_DELAY_INIT
> + /* initialize video mode immediately (the first one) */
> + fb_activate_mode(fb_dev, &host->mode[0]);
> +#endif
> +#ifndef CONFIG_VIDEO_DELAY_ENABLING
> + /* enable video output immediately */
> + (host->fb_enable)(info);
> +#endif
> + return 0;
> +}
> +
> +static struct driver_d fb_driver = {
> + .name = "framebuffer",
> + .probe = fb_probe,
> +};
> +
> +static int framebuffer_init(void)
> +{
> + return register_driver(&fb_driver);
> +}
> +
> +device_initcall(framebuffer_init);
> +
> +struct device_d *register_framebuffer(struct fb_host *host, void *base, unsigned size)
> +{
> + struct device_d *fb_dev;
> + int rc;
> +
> + fb_dev = xzalloc(sizeof(struct device_d));
> +
> + strcpy(fb_dev->name, fb_driver.name);
> + fb_dev->platform_data = (void*)host;
> +
> + /* setup the defaults for this framebuffer if given */
> + fb_dev->size = size;
> + fb_dev->map_base = (unsigned long)base;
> +
> + rc = register_device(fb_dev);
> + if (rc != 0) {
> + pr_debug("Cannot register framebuffer device\n");
> + free(fb_dev);
> + return NULL;
> + }
> +
> + return fb_dev;
> +}
> +#endif
> +
> int register_framebuffer(struct fb_info *info)
> {
> int id = get_free_deviceid("fb");
> diff --git a/include/fb.h b/include/fb.h
> index 218b244..96edc24 100644
> --- a/include/fb.h
> +++ b/include/fb.h
> @@ -85,6 +85,46 @@ struct fb_ops {
> void (*fb_disable)(struct fb_info *info);
> };
>
> +#if 0
> +struct fb_host {
> + const struct fb_videomode *mode;
> + unsigned mode_cnt;
> +
> + struct device_d *hw_dev;
> +
> + /* callbacks into the video hardware driver */
> + int (*fb_setcolreg)(struct fb_info*, unsigned, unsigned, unsigned, unsigned, unsigned);
> + int (*fb_mode)(struct fb_info*, const struct fb_videomode*);
> + void (*fb_enable)(struct fb_info*);
> + void (*fb_disable)(struct fb_info*);
> +
> + unsigned bits_per_pixel;
> +};
> +
> +struct fb_info {
> + struct fb_host *host;
> + struct device_d *fb_dev;
> + const struct fb_videomode *active_mode;
> +
> + u32 xres; /* visible resolution */
> + u32 yres;
> + u32 bits_per_pixel; /* guess what */
> +
> + u32 grayscale; /* != 0 Graylevels instead of colors */
> +
> + struct fb_bitfield red; /* bitfield in fb mem if true color, */
> + struct fb_bitfield green; /* else only length is significant */
> + struct fb_bitfield blue;
> + struct fb_bitfield transp; /* transparency */
> +
> +#ifdef CONFIG_VIDEO_DELAY_ENABLING
> + int enabled;
> +#endif
> +};
> +
> +struct device_d *register_framebuffer(struct fb_host*, void*, unsigned);
> +#endif
> +
> struct fb_info {
> struct fb_videomode *mode;
>
> --
> 1.7.2.3
>
>
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