[PATCH 03/12] Bring in dynamic videomode selection at runtime
Sascha Hauer
s.hauer at pengutronix.de
Mon Nov 1 09:47:14 EDT 2010
On Tue, Oct 26, 2010 at 01:31:39PM +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" should be merged, prior the final commit onto the repository.
>
> This step brings in the required function for dynamic videomode selection at
> runtime but keep the old functions untouched (the new one 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 | 13 +++
> drivers/video/fb.c | 243 +++++++++++++++++++++++++++++++++++++++++++++++++
> include/fb.h | 40 ++++++++
> 3 files changed, 296 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig
> --- 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 +60,139 @@ 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);
We have dev_err, also this line is really long.
> +
> + if (enable) {
> + (host->fb_enable)(info);
Please do not add these unnecessary braces around function pointers.
> + new = "1";
> + } else {
> + (host->fb_disable)(info);
> + new = "0";
> + }
> +
> + info->enabled = !!enable;
> +
> + return dev_param_set_generic(fb_dev, param, new);
> +}
> +
> +static void fb_list_modes(struct fb_host *host)
> +{
> + unsigned u;
> +
> + if (host->mode_cnt == 0)
> + return;
This is not needed.
> +
> + 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 +201,113 @@ 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
> + dev_add_param(fb_dev, "enable", fb_enable_set, NULL, 0);
> + /* default is 'off' for delayed video output */
> + 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];
Why this? struct fb_info contains a struct cdev which is probably
removed in a later patch in this series. The current implementation
is clearly easier to read than this &cdev[1] construct.
> +
> + 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 */
No, this does not mean RGB565. It could also mean BGR or even something
else.
> +
> + /* add params on demand */
There is no information in this comment.
> + 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
> + 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 */
If you go the way of duplicating the code and removing the old code
afterwards I would assume that you add the code in the right way and
start to add doxygen from the beginning instead of fixing it later.
> +
> +#ifdef CONFIG_VIDEO_DELAY_ENABLING
> + int enabled;
> +#endif
> +};
This is unused and removed in a later patch.
Sascha
--
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