Re: simple-framebuffer enquire
From: Hans de Goede <hidden>
Date: 2018-06-26 10:01:46
Also in:
lkml
Hi, On 25-06-18 15:29, Michael Nazzareno Trimarchi wrote:
quoted hunk ↗ jump to hunk
Hi Hans In order to let it even registered the simplefb I have added this change. According on what I understand from the code seems that this is the way to acquire memory with the correct attributediff --git a/drivers/video/fbdev/simplefb.c b/drivers/video/fbdev/simplefb.c index a3c44ec..7e61ce3 100644 --- a/drivers/video/fbdev/simplefb.c +++ b/drivers/video/fbdev/simplefb.c@@ -466,8 +466,8 @@ static int simplefb_probe(struct platform_device *pdev) info->fbops = &simplefb_ops; info->flags = FBINFO_DEFAULT | FBINFO_MISC_FIRMWARE; - info->screen_base = ioremap_wc(info->fix.smem_start, - info->fix.smem_len); + info->screen_base = arch_memremap_wb(info->fix.smem_start, + info->fix.smem_len);
I'm not sure why you need this? wb certainly is not optimal for a framebuffer, the existing wc mapping is really what you want.
if (!info->screen_base) {
ret = -ENOMEM;
goto error_fb_release;
Another question is
aliases {
display0 = &lcdif;
};
chosen {
#address-cells = <1>;
#size-cells = <1>;
ranges;
stdout-path = &uart1;
framebuffer0: framebuffer@86fd6080 {
compatible = "simple-framebuffer";
reg = <0x86fd6080 (480 * 272 * 4)>;
width = <480>;
height = <272>;
stride = <(480 * 4)>;
format = "a8r8g8b8";
clocks = <&clks IMX6UL_CLK_LCDIF_PIX>,
<&clks IMX6UL_CLK_LCDIF_APB>,
<&clks IMX6UL_CLK_DUMMY>,
<&clks IMX6UL_CLK_GPIO3>,
<&clks IMX6UL_CLK_GPIO4>;
nshut-supply = <®_lcd_nshut>;
nreset-supply = <®_lcd_nreset>;This looks like GPIOS to me why are you modeling this a supplies? Anyways ...
display = <&lcdif>;
};
};
};
How do you ensure that regulators that are bind to gpios can be
maintain during boot?Any regulators listed in the simplefb dt-node will be kept enabled until remove_conflicting_framebuffers is called() from the native display driver. To keep them enabled while loading the native display driver, you should get and enable them in the native display driver *before* calling remove_conflicting_framebuffers() (and the same goes for the clocks). Regards, Hans
A small minor comment is how to automatic switch then to normal
framebuffer. Anyway seems
that
#address-cells = <1>;
#size-cells = <1>;
ranges;
are mandatory and they are in the dts documentation.
Best regards
Michael