Re: [PATCH 1/1] New Framebuffer for Intel based Macs

["Antonino A. Daplas" <adaplas@gmail.com>]

Edgar Hucek wrote:
> This patch add a new framebuffer driver for the Intel Based macs.
> This framebuffer is needed when booting from EFI to get something
> out the box ;)
>

A few comments below, but I don't think they are serious enough to
prevent this driver from inclusion.
 
> Signed-off-by: Edgar Hucek <hostmaster@ed-soft.at>
> 
> 
> ------------------------------------------------------------------------
> 
> diff -uNr linux-2.6.17.orig/drivers/video/imacfb.c linux-2.6.17/drivers/video/imacfb.c
> --- linux-2.6.17.orig/drivers/video/imacfb.c	1970-01-01 01:00:00.000000000 +0100
> +++ linux-2.6.17/drivers/video/imacfb.c	2006-06-18 11:46:13.000000000 +0200
> @@ -0,0 +1,436 @@
> +/*
> + * framebuffer driver for Intel Based Mac's
> + *
> + * (c) 2006 Edgar Hucek <gimli@dark-green.com>
> + * Original vesa driver written by Gerd Knorr <kraxel@goldbach.in-berlin.de>
> + *
> + */
> +
> +#include <linux/module.h>
> +#include <linux/kernel.h>
> +#include <linux/errno.h>
> +#include <linux/string.h>
> +#include <linux/mm.h>
> +#include <linux/tty.h>
> +#include <linux/slab.h>
> +#include <linux/delay.h>
> +#include <linux/fb.h>
> +#include <linux/ioport.h>
> +#include <linux/init.h>
> +#include <linux/platform_device.h>
> +
> +#include <video/vga.h>
> +#include <asm/io.h>
> +#include <asm/mtrr.h>
> +
> +#define dac_reg	(0x3c8)
> +#define dac_val	(0x3c9)
> +
> +typedef enum _MAC_TAPE {
> +	M_I17,
> +	M_I20,
> +	M_MINI,
> +	M_MACBOOK,
> +	M_NEW
> +} MAC_TAPE;
> +
> +/* --------------------------------------------------------------------- */
> +
> +static struct fb_var_screeninfo imacfb_defined __initdata = {
> +      	.activate	= FB_ACTIVATE_NOW,
> +	.height		= -1,
> +	.width		= -1,
> +	.right_margin	= 32,
> +	.upper_margin	= 16,
> +	.lower_margin	= 4,
> +	.vsync_len	= 4,
> +	.vmode		= FB_VMODE_NONINTERLACED,
> +};
> +
> +static struct fb_fix_screeninfo imacfb_fix __initdata = {
> +	.id	= "IMAC VGA",
> +	.type	= FB_TYPE_PACKED_PIXELS,
> +	.accel	= FB_ACCEL_NONE,
> +};
> +
> +static int             inverse   = 0;
> +static int             mtrr      = 0; /* disable mtrr */
> +static int	       vram_remap __initdata = 0; /* Set amount of memory to be used */
> +static int	       vram_total __initdata = 0; /* Set total amount of memory */
> +static int             depth;
> +static int             model = M_NEW;
> +static int             manual_height = 0;
> +static int             manual_width = 0;
> +
> +/* --------------------------------------------------------------------- */
> +
> +static int imacfb_setcolreg(unsigned regno, unsigned red, unsigned green,
> +			    unsigned blue, unsigned transp,
> +			    struct fb_info *info)
> +{
> +	/*
> +	 *  Set a single color register. The values supplied are
> +	 *  already rounded down to the hardware's capabilities
> +	 *  (according to the entries in the `var' structure). Return
> +	 *  != 0 for invalid regno.
> +	 */
> +	
> +	if (regno >= info->cmap.len)
> +		return 1;
> +
> +	if (regno < 16 && info->var.bits_per_pixel != 8) {
> +		switch (info->var.bits_per_pixel) {
> +		case 16:
> +			if (info->var.red.offset == 10) {
> +				/* 1:5:5:5 */
> +				((u32*) (info->pseudo_palette))[regno] =
> +					((red   & 0xf800) >>  1) |
> +					((green & 0xf800) >>  6) |
> +					((blue  & 0xf800) >> 11);
> +			} else {
> +				/* 0:5:6:5 */
> +				((u32*) (info->pseudo_palette))[regno] =
> +					((red   & 0xf800)      ) |
> +					((green & 0xfc00) >>  5) |
> +					((blue  & 0xf800) >> 11);
> +			}
> +			break;
> +		case 24:
> +		case 32:
> +			red   >>= 8;
> +			green >>= 8;
> +			blue  >>= 8;
> +			((u32 *)(info->pseudo_palette))[regno] =
> +				(red   << info->var.red.offset)   |
> +				(green << info->var.green.offset) |
> +				(blue  << info->var.blue.offset);
> +			break;
> +		}
> +	}
> +
> +	return 0;
> +}
> +
> +static struct fb_ops imacfb_ops = {
> +	.owner		= THIS_MODULE,
> +	.fb_setcolreg	= imacfb_setcolreg,
> +	.fb_fillrect	= cfb_fillrect,
> +	.fb_copyarea	= cfb_copyarea,
> +	.fb_imageblit	= cfb_imageblit,
> +};
> +
> +static int __init imacfb_setup(char *options)
> +{
> +	char *this_opt;
> +	
> +	if (!options || !*options)
> +		return 0;
> +	
> +	while ((this_opt = strsep(&options, ",")) != NULL) {
> +		if (!*this_opt) continue;
> +		
> +		if (! strcmp(this_opt, "inverse"))
> +			inverse=1;
> +		else if (! strncmp(this_opt, "mtrr:", 5))
> +			mtrr = simple_strtoul(this_opt+5, NULL, 0);
> +		else if (! strcmp(this_opt, "nomtrr"))
> +			mtrr=0;
> +		else if (! strncmp(this_opt, "vtotal:", 7))
> +			vram_total = simple_strtoul(this_opt+7, NULL, 0);
> +		else if (! strncmp(this_opt, "vremap:", 7))
> +			vram_remap = simple_strtoul(this_opt+7, NULL, 0);
> +		else if (! strcmp(this_opt, "i17"))
> +			model = M_I17;
> +		else if (! strcmp(this_opt, "i20"))
> +			model = M_I20;
> +		else if (! strcmp(this_opt, "mini"))
> +			model = M_MINI;
> +		else if (! strcmp(this_opt, "macbook"))
> +			model = M_MACBOOK;> +}
> +
> +static struct platform_driver imacfb_driver = {
> +	.probe	= imacfb_probe,
> +	.driver	= {
> +		.name	= "imacfb",
> +	},
> +};
> +
> +static struct platform_device imacfb_device = {
> +	.name	= "imacfb",
> +};
> +
> +static int __init imacfb_init(void)
> +{
> +	int ret;
> +	char *option = NULL;
> +
> +	/* ignore error return of fb_get_options */
> +	fb_get_options("imacfb", &option);
> +	imacfb_setup(option);
> +	ret = platform_driver_register(&imacfb_driver);
> +
> +	if (!ret) {
> +		ret = platform_device_register(&imacfb_device);
> +		if (ret)
> +			platform_driver_unregister(&imacfb_driver);
> +	}
> +	return ret;
> +}
> +module_init(imacfb_init);
> +
> +MODULE_LICENSE("GPL");
> diff -uNr linux-2.6.17.orig/drivers/video/Kconfig linux-2.6.17/drivers/video/Kconfig
> --- linux-2.6.17.orig/drivers/video/Kconfig	2006-06-18 11:45:31.000000000 +0200
> +++ linux-2.6.17/drivers/video/Kconfig	2006-06-18 11:46:03.000000000 +0200
> @@ -483,6 +483,15 @@
>  	  You will get a boot time penguin logo at no additional cost. Please
>  	  read <file:Documentation/fb/vesafb.txt>. If unsure, say Y.
>  
> +config FB_IMAC
> +	bool "Intel Based Macs FB"
> +	depends on (FB = y) && X86
> +	select FB_CFB_FILLRECT
> +	select FB_CFB_COPYAREA
> +	select FB_CFB_IMAGEBLIT
> +	help
> +	  This is the frame buffer device driver for the Inel Based Mac's
> +
>  config VIDEO_SELECT
>  	bool
>  	depends on FB_VESA
> diff -uNr linux-2.6.17.orig/drivers/video/Makefile linux-2.6.17/drivers/video/Makefile
> --- linux-2.6.17.orig/drivers/video/Makefile	2006-06-18 11:45:31.000000000 +0200
> +++ linux-2.6.17/drivers/video/Makefile	2006-06-18 11:46:03.000000000 +0200
> @@ -97,6 +97,7 @@
>  
>  # Platform or fallback drivers go here
>  obj-$(CONFIG_FB_VESA)             += vesafb.o
> +obj-$(CONFIG_FB_IMAC)             += imacfb.o
>  obj-$(CONFIG_FB_VGA16)            += vga16fb.o vgastate.o
>  obj-$(CONFIG_FB_OF)               += offb.o
>  


> +		else if (! strncmp(this_opt, "height:", 7))
> +			manual_height = simple_strtoul(this_opt+7, NULL, 0);
> +		else if (! strncmp(this_opt, "width:", 6))
> +			manual_width = simple_strtoul(this_opt+6, NULL, 0);
> +	}
> +	return 0;
> +}
> +
> +#define	DEFAULT_FB_MEM	1024*1024*16
> +
> +static int __init imacfb_probe(struct platform_device *dev)
> +{
> +	struct fb_info *info;
> +	int err;
> +	unsigned int size_vmode;
> +	unsigned int size_remap;
> +	unsigned int size_total;
> +
> +	screen_info.lfb_depth = 32;
> +	screen_info.lfb_size = DEFAULT_FB_MEM / 0x10000;
> +	screen_info.pages=1;
> +	screen_info.blue_size = 8;
> +	screen_info.blue_pos = 0;
> +	screen_info.green_size = 8;
> +	screen_info.green_pos = 8;
> +	screen_info.red_size = 8;
> +	screen_info.red_pos = 16;
> +	screen_info.rsvd_size = 8;
> +	screen_info.rsvd_pos = 24;
> +
> +	switch(model) {
> +		case M_I17:
> +			screen_info.lfb_width = 1440;
> +			screen_info.lfb_height = 900;
> +			screen_info.lfb_linelength = 1472 * 4;
> +			screen_info.lfb_base = 0x80010000;
> +			break;
> +		case M_NEW:
> +		case M_I20:
> +			screen_info.lfb_width = 1680;
> +			screen_info.lfb_height = 1050;
> +			screen_info.lfb_linelength = 1728 * 4;
> +			screen_info.lfb_base = 0x80010000;
> +			break;
> +		case M_MINI:
> +			screen_info.lfb_width = 1024;
> +			screen_info.lfb_height = 768;
> +			screen_info.lfb_linelength = 2048 * 4;
> +			screen_info.lfb_base = 0x80000000;
> +			break;
> +		case M_MACBOOK:
> +			screen_info.lfb_width = 1280;
> +			screen_info.lfb_height = 800;
> +			screen_info.lfb_linelength = 2048 * 4;
> +			screen_info.lfb_base = 0x80000000;
> +			break;
> + 	}
> +
> +	/* if the user wants to manually specify height/width,
> +	   we will override the defaults */
> +	/* TODO: eventually get auto-detection working */
> +	if(manual_height > 0)
> +		screen_info.lfb_height = manual_height;
> +	if(manual_width > 0)
> +		screen_info.lfb_width = manual_width;
> +
> +	/*
> +	static void *videomemory;
> +	static u_long videomemorysize = (64*1024*1024);
> +	videomemory = ioremap(0x80000000,videomemorysize);
> +	memset(videomemory, 0x99, videomemorysize);
> +	*/
> +
> +	imacfb_fix.smem_start = screen_info.lfb_base;
> +	imacfb_defined.bits_per_pixel = screen_info.lfb_depth;
> +	if (15 == imacfb_defined.bits_per_pixel)
> +		imacfb_defined.bits_per_pixel = 16;
> +	imacfb_defined.xres = screen_info.lfb_width;
> +	imacfb_defined.yres = screen_info.lfb_height;
> +	imacfb_fix.line_length = screen_info.lfb_linelength;
> +	imacfb_fix.visual   = (imacfb_defined.bits_per_pixel == 8) ?
> +		FB_VISUAL_PSEUDOCOLOR : FB_VISUAL_TRUECOLOR;

If the hardware/driver does not have the capability to set the
hardware palette at 8 bpp, change the visual to STATIC_PSEUDOCOLOR
instead.

And in imacfb_setcolreg(), when the current visual is STATIC_PSEUDOCOLOR
then return nonzero.

(I did notice that everything is currently hard-coded at 32-bpp, so I'm
assuming that this will change in the future.  If it does not, then this
driver has a lot of dead code.)

> +
> +	/*   size_vmode -- that is the amount of memory needed for the
> +	 *                 used video mode, i.e. the minimum amount of
> +	 *                 memory we need. */
> +	size_vmode = imacfb_defined.yres * imacfb_fix.line_length;
> +
> +	/*   size_total -- all video memory we have. Used for mtrr
> +	 *                 entries, ressource allocation and bounds
> +	 *                 checking. */
> +	size_total = screen_info.lfb_size * 65536;
> +	if (vram_total)
> +		size_total = vram_total * 1024 * 1024;
> +	if (size_total < size_vmode)
> +		size_total = size_vmode;
> +
> +	/*   size_remap -- the amount of video memory we are going to
> +	 *                 use for imacfb.  With modern cards it is no
> +	 *                 option to simply use size_total as that
> +	 *                 wastes plenty of kernel address space. */
> +	size_remap  = size_vmode * 2;
> +	if (vram_remap)
> +		size_remap = vram_remap * 1024 * 1024;
> +	if (size_remap < size_vmode)
> +		size_remap = size_vmode;
> +	if (size_remap > size_total)
> +		size_remap = size_total;
> +	imacfb_fix.smem_len = size_remap;
> +
> +#ifndef __i386__
> +	screen_info.imacpm_seg = 0;
> +#endif
> +
> +	if (!request_mem_region(imacfb_fix.smem_start, size_total, "imacfb")) {
> +		printk(KERN_WARNING
> +		       "imacfb: cannot reserve video memory at 0x%lx\n",
> +			imacfb_fix.smem_start);
> +		/* We cannot make this fatal. Sometimes this comes from magic
> +		   spaces our resource handlers simply don't know about */
> +	}
> +
> +	info = framebuffer_alloc(sizeof(u32) * 256, &dev->dev);

sizeof(u32) * 256 is too much. You can use sizeof(u32) * 16.

> +	if (!info) {
> +		release_mem_region(imacfb_fix.smem_start, size_total);
> +		return -ENOMEM;
> +	}
> +	info->pseudo_palette = info->par;
> +	info->par = NULL;
> +
> +	info->screen_base = ioremap(imacfb_fix.smem_start, imacfb_fix.smem_len);
> +	if (!info->screen_base) {
> +		printk(KERN_ERR
> +		       "imacfb: abort, cannot ioremap video memory 0x%x @ 0x%lx\n",
> +			imacfb_fix.smem_len, imacfb_fix.smem_start);
> +		err = -EIO;
> +		goto err;
> +	}
> +
> +	printk(KERN_INFO "imacfb: framebuffer at 0x%lx, mapped to 0x%p, "
> +	       "using %dk, total %dk\n",
> +	       imacfb_fix.smem_start, info->screen_base,
> +	       size_remap/1024, size_total/1024);
> +	printk(KERN_INFO "imacfb: mode is %dx%dx%d, linelength=%d, pages=%d\n",
> +	       imacfb_defined.xres, imacfb_defined.yres, imacfb_defined.bits_per_pixel, imacfb_fix.line_length, screen_info.pages);
> +
> +	imacfb_defined.xres_virtual = imacfb_defined.xres;
> +	imacfb_defined.yres_virtual = imacfb_fix.smem_len / imacfb_fix.line_length;
> +	printk(KERN_INFO "imacfb: scrolling: redraw\n");
> +	imacfb_defined.yres_virtual = imacfb_defined.yres;
> +
> +	/* some dummy values for timing to make fbset happy */
> +	imacfb_defined.pixclock     = 10000000 / imacfb_defined.xres * 1000 / imacfb_defined.yres;
> +	imacfb_defined.left_margin  = (imacfb_defined.xres / 8) & 0xf8;
> +	imacfb_defined.hsync_len    = (imacfb_defined.xres / 8) & 0xf8;
> +	
> +	imacfb_defined.red.offset    = screen_info.red_pos;
> +	imacfb_defined.red.length    = screen_info.red_size;
> +	imacfb_defined.green.offset  = screen_info.green_pos;
> +	imacfb_defined.green.length  = screen_info.green_size;
> +	imacfb_defined.blue.offset   = screen_info.blue_pos;
> +	imacfb_defined.blue.length   = screen_info.blue_size;
> +	imacfb_defined.transp.offset = screen_info.rsvd_pos;
> +	imacfb_defined.transp.length = screen_info.rsvd_size;
> +
> +	if (imacfb_defined.bits_per_pixel <= 8) {
> +		depth = imacfb_defined.green.length;
> +		imacfb_defined.red.length =
> +		imacfb_defined.green.length =
> +		imacfb_defined.blue.length =
> +		imacfb_defined.bits_per_pixel;
> +	}
> +
> +	printk(KERN_INFO "imacfb: %s: "
> +	       "size=%d:%d:%d:%d, shift=%d:%d:%d:%d\n",
> +	       (imacfb_defined.bits_per_pixel > 8) ?
> +	       "Truecolor" : "Pseudocolor",
> +	       screen_info.rsvd_size,
> +	       screen_info.red_size,
> +	       screen_info.green_size,
> +	       screen_info.blue_size,
> +	       screen_info.rsvd_pos,
> +	       screen_info.red_pos,
> +	       screen_info.green_pos,
> +	       screen_info.blue_pos);
> +
> +	imacfb_fix.ypanstep  = 0;
> +	imacfb_fix.ywrapstep = 0;
> +
> +	/* request failure does not faze us, as vgacon probably has this
> +	 * region already (FIXME) */
> +	request_region(0x3c0, 32, "imacfb");
> +
> +#ifdef CONFIG_MTRR
> +	if (mtrr) {
> +		unsigned int temp_size = size_total;
> +		unsigned int type = 0;
> +
> +		switch (mtrr) {
> +		case 1:
> +			type = MTRR_TYPE_UNCACHABLE;
> +			break;
> +		case 2:
> +			type = MTRR_TYPE_WRBACK;
> +			break;
> +		case 3:
> +			type = MTRR_TYPE_WRCOMB;
> +			break;
> +		case 4:
> +			type = MTRR_TYPE_WRTHROUGH;
> +			break;
> +		default:
> +			type = 0;
> +			break;
> +		}
> +
> +		if (type) {
> +			int rc;
> +
> +			/* Find the largest power-of-two */
> +			while (temp_size & (temp_size - 1))
> +				temp_size &= (temp_size - 1);
> +
> +			/* Try and find a power of two to add */
> +			do {
> +				rc = mtrr_add(imacfb_fix.smem_start, temp_size,
> +					      type, 1);
> +				temp_size >>= 1;
> +			} while (temp_size >= PAGE_SIZE && rc == -EINVAL);
> +		}
> +	}
> +#endif
> +	
> +	info->fbops = &imacfb_ops;
> +	info->var = imacfb_defined;
> +	info->fix = imacfb_fix;
> +	info->flags = FBINFO_FLAG_DEFAULT;
> +
> +	if (fb_alloc_cmap(&info->cmap, 256, 0) < 0) {
> +		err = -ENOMEM;
> +		goto err;
> +	}
> +	if (register_framebuffer(info)<0) {
> +		err = -EINVAL;
> +		fb_dealloc_cmap(&info->cmap);
> +		goto err;
> +	}
> +	printk(KERN_INFO "fb%d: %s frame buffer device\n",
> +	       info->node, info->fix.id);
> +	return 0;
> +err:
> +	framebuffer_release(info);
> +	release_mem_region(imacfb_fix.smem_start, size_total);
> +	return err;

Balance the error path.  I don't see any iounmap(), mtrr_del() or
release_region().

vesafb suffers from the same problem, but this is a new driver :-)

Tony