The naming scheme of simplefb's mode is precise enough to allow building the mode structure from it instead of using a static list of modes. This patch introduces a function that does this. In case exotic modes that cannot be represented from their name alone are needed, the static list of modes is still available as a backup.
Signed-off-by: Alexandre Courbot <[email protected]> --- Stephen, please note that the "r5g6b5" mode initially supported by the driver becomes "b5g6r5" with the new function. This is because the least significant bits are defined first in the string - this makes parsing much easier, notably for modes which do not fill whole bytes (e.g. 15 bit modes). I hope this is not a problem - it's probably better to do the change now while the driver is still new. .../bindings/video/simple-framebuffer.txt | 12 +++- drivers/video/simplefb.c | 66 +++++++++++++++++++++- 2 files changed, 73 insertions(+), 5 deletions(-) diff --git a/Documentation/devicetree/bindings/video/simple-framebuffer.txt b/Documentation/devicetree/bindings/video/simple-framebuffer.txt index 3ea4605..f933b3d 100644 --- a/Documentation/devicetree/bindings/video/simple-framebuffer.txt +++ b/Documentation/devicetree/bindings/video/simple-framebuffer.txt @@ -10,8 +10,16 @@ Required properties: - width: The width of the framebuffer in pixels. - height: The height of the framebuffer in pixels. - stride: The number of bytes in each line of the framebuffer. -- format: The format of the framebuffer surface. Valid values are: - - r5g6b5 (16-bit pixels, d[15:11]=r, d[10:5]=g, d[4:0]=b). +- format: The format of the framebuffer surface. Described as a sequence of + channel/nbbits pairs, where each pair describes how many bits are used + by a given color channel. Value channels are "r" (red), "g" (green), + "b" (blue) and "a" (alpha). Channels are listed starting in + bit-significance order. For instance, a format named "r5g6b5" describes + a 16-bit format where red is encoded in the 5 less significant bits, + green in the 6 following ones, and blue in the 5 last: + BBBBBGGG GGGRRRRR + ^ ^ + MSB LSB Example: diff --git a/drivers/video/simplefb.c b/drivers/video/simplefb.c index 8105c3d..1a1be71 100644 --- a/drivers/video/simplefb.c +++ b/drivers/video/simplefb.c @@ -21,6 +21,7 @@ */ #include <linux/errno.h> +#include <linux/ctype.h> #include <linux/fb.h> #include <linux/io.h> #include <linux/module.h> @@ -82,8 +83,64 @@ struct simplefb_format { struct fb_bitfield transp; }; -struct simplefb_format simplefb_formats[] = { - { "r5g6b5", 16, {11, 5}, {5, 6}, {0, 5}, {0, 0} }, +static struct simplefb_format *simplefb_parse_format(struct device *dev, + const char *str) +{ + struct simplefb_format *format; + unsigned int cpt = 0; + unsigned int i = 0; + + format = devm_kzalloc(dev, sizeof(*format), GFP_KERNEL); + if (!format) + return ERR_PTR(-ENOMEM); + + while (str[i] != 0) { + struct fb_bitfield *field = 0; + char c = str[i++]; + + switch (c) { + case 'r': + case 'R': + field = &format->red; + break; + case 'g': + case 'G': + field = &format->green; + break; + case 'b': + case 'B': + field = &format->blue; + break; + case 'a': + case 'A': + field = &format->transp; + break; + default: + goto error; + } + + c = str[i++]; + if (c == 0 || !isdigit(c)) + goto error; + + field->offset = cpt; + field->length = c - '0'; + + cpt += field->length; + } + + format->bits_per_pixel = ((cpt + 7) / 8) * 8; + format->name = str; + return format; + +error: + dev_err(dev, "Invalid format string\n"); + return ERR_PTR(-EINVAL); +} + +/* if you use exotic modes that simplefb_parse_format cannot decode, you can + specify them here. */ +static struct simplefb_format simplefb_formats[] = { }; struct simplefb_params { @@ -131,7 +188,10 @@ static int simplefb_parse_dt(struct platform_device *pdev, params->format = &simplefb_formats[i]; break; } - if (!params->format) { + if (!params->format) + params->format = simplefb_parse_format(&pdev->dev, format); + + if (!params->format || IS_ERR(params->format)) { dev_err(&pdev->dev, "Invalid format value\n"); return -EINVAL; } -- 1.8.2.3 _______________________________________________ devicetree-discuss mailing list [email protected] https://lists.ozlabs.org/listinfo/devicetree-discuss
