On Sun, Mar 10, 2019 at 12:22:17AM +0100, BALATON Zoltan wrote: > This adds DDC support to ati-vga and connects i2c-ddc to provide EDID > info that is read by guests to find available screen modes. Not sure > if this is 100% correct yet but at least MorphOS is happy with it and > starts in a high resolution mode instead of 640x480 (although its > splash screen is still not correct).
> Linux needs support from VESA > vgabios, it seems to be missing INT10 0x4F15 function (see > https://gitlab.freedesktop.org/xorg/xserver/blob/master/hw/xfree86/vbe/vbe.c) > without which no DDC is available that also prevents loading the > accelerated X driver. radeonfb doesn't pick up the edid either. There seem to be four i2c busses though: void radeon_create_i2c_busses(struct radeonfb_info *rinfo) { rinfo->i2c[0].rinfo = rinfo; rinfo->i2c[0].ddc_reg = GPIO_MONID; #ifndef CONFIG_PPC rinfo->i2c[0].adapter.class = I2C_CLASS_HWMON; #endif radeon_setup_i2c_bus(&rinfo->i2c[0], "monid"); rinfo->i2c[1].rinfo = rinfo; rinfo->i2c[1].ddc_reg = GPIO_DVI_DDC; radeon_setup_i2c_bus(&rinfo->i2c[1], "dvi"); rinfo->i2c[2].rinfo = rinfo; rinfo->i2c[2].ddc_reg = GPIO_VGA_DDC; radeon_setup_i2c_bus(&rinfo->i2c[2], "vga"); rinfo->i2c[3].rinfo = rinfo; rinfo->i2c[3].ddc_reg = GPIO_CRT2_DDC; radeon_setup_i2c_bus(&rinfo->i2c[3], "crt2"); } aty128fb has no i2c support. > Besides, this depends on bitbang_i2c.h which is now in hw/i2c so if > including it from there is not desirable that may need to be moved > somewhere. include/hw/i2c/ looks like a sensible location to me. cheers, Gerd
