imxfb.c

linux 内核源代码

/*
 *  linux/drivers/video/imxfb.c
 *
 *  Freescale i.MX Frame Buffer device driver
 *
 *  Copyright (C) 2004 Sascha Hauer, Pengutronix
 *   Based on acornfb.c Copyright (C) Russell King.
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file COPYING in the main directory of this archive for
 * more details.
 *
 * Please direct your questions and comments on this driver to the following
 * email address:
 *
 *	[e-mail]
 */

//#define DEBUG 1

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/interrupt.h>
#include <linux/slab.h>
#include <linux/fb.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/cpufreq.h>
#include <linux/platform_device.h>
#include <linux/dma-mapping.h>

#include <asm/hardware.h>
#include <asm/io.h>
#include <asm/arch/imxfb.h>

/*
 * Complain if VAR is out of range.
 */
#define DEBUG_VAR 1

#include "imxfb.h"

static struct imxfb_rgb def_rgb_16 = {
	.red	= { .offset = 8,  .length = 4, },
	.green	= { .offset = 4,  .length = 4, },
	.blue	= { .offset = 0,  .length = 4, },
	.transp = { .offset = 0,  .length = 0, },
};

static struct imxfb_rgb def_rgb_8 = {
	.red	= { .offset = 0,  .length = 8, },
	.green	= { .offset = 0,  .length = 8, },
	.blue	= { .offset = 0,  .length = 8, },
	.transp = { .offset = 0,  .length = 0, },
};

static int imxfb_activate_var(struct fb_var_screeninfo *var, struct fb_info *info);

static inline u_int chan_to_field(u_int chan, struct fb_bitfield *bf)
{
	chan &= 0xffff;
	chan >>= 16 - bf->length;
	return chan << bf->offset;
}

#define LCDC_PALETTE(x) __REG2(IMX_LCDC_BASE+0x800, (x)<<2)
static int
imxfb_setpalettereg(u_int regno, u_int red, u_int green, u_int blue,
		       u_int trans, struct fb_info *info)
{
	struct imxfb_info *fbi = info->par;
	u_int val, ret = 1;

#define CNVT_TOHW(val,width) ((((val)<<(width))+0x7FFF-(val))>>16)
	if (regno < fbi->palette_size) {
		val = (CNVT_TOHW(red, 4) << 8) |
		      (CNVT_TOHW(green,4) << 4) |
		      CNVT_TOHW(blue,  4);

		LCDC_PALETTE(regno) = val;
		ret = 0;
	}
	return ret;
}

static int
imxfb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
		   u_int trans, struct fb_info *info)
{
	struct imxfb_info *fbi = info->par;
	unsigned int val;
	int ret = 1;

	/*
	 * If inverse mode was selected, invert all the colours
	 * rather than the register number.  The register number
	 * is what you poke into the framebuffer to produce the
	 * colour you requested.
	 */
	if (fbi->cmap_inverse) {
		red   = 0xffff - red;
		green = 0xffff - green;
		blue  = 0xffff - blue;
	}

	/*
	 * If greyscale is true, then we convert the RGB value
	 * to greyscale no mater what visual we are using.
	 */
	if (info->var.grayscale)
		red = green = blue = (19595 * red + 38470 * green +
					7471 * blue) >> 16;

	switch (info->fix.visual) {
	case FB_VISUAL_TRUECOLOR:
		/*
		 * 12 or 16-bit True Colour.  We encode the RGB value
		 * according to the RGB bitfield information.
		 */
		if (regno < 16) {
			u32 *pal = info->pseudo_palette;

			val  = chan_to_field(red, &info->var.red);
			val |= chan_to_field(green, &info->var.green);
			val |= chan_to_field(blue, &info->var.blue);

			pal[regno] = val;
			ret = 0;
		}
		break;

	case FB_VISUAL_STATIC_PSEUDOCOLOR:
	case FB_VISUAL_PSEUDOCOLOR:
		ret = imxfb_setpalettereg(regno, red, green, blue, trans, info);
		break;
	}

	return ret;
}

/*
 *  imxfb_check_var():
 *    Round up in the following order: bits_per_pixel, xres,
 *    yres, xres_virtual, yres_virtual, xoffset, yoffset, grayscale,
 *    bitfields, horizontal timing, vertical timing.
 */
static int
imxfb_check_var(struct fb_var_screeninfo *var, struct fb_info *info)
{
	struct imxfb_info *fbi = info->par;
	int rgbidx;

	if (var->xres < MIN_XRES)
		var->xres = MIN_XRES;
	if (var->yres < MIN_YRES)
		var->yres = MIN_YRES;
	if (var->xres > fbi->max_xres)
		var->xres = fbi->max_xres;
	if (var->yres > fbi->max_yres)
		var->yres = fbi->max_yres;
	var->xres_virtual = max(var->xres_virtual, var->xres);
	var->yres_virtual = max(var->yres_virtual, var->yres);

	pr_debug("var->bits_per_pixel=%d\n", var->bits_per_pixel);
	switch (var->bits_per_pixel) {
	case 16:
		rgbidx = RGB_16;
		break;
	case 8:
		rgbidx = RGB_8;
		break;
	default:
		rgbidx = RGB_16;
	}

	/*
	 * Copy the RGB parameters for this display
	 * from the machine specific parameters.
	 */
	var->red    = fbi->rgb[rgbidx]->red;
	var->green  = fbi->rgb[rgbidx]->green;
	var->blue   = fbi->rgb[rgbidx]->blue;
	var->transp = fbi->rgb[rgbidx]->transp;

	pr_debug("RGBT length = %d:%d:%d:%d\n",
		var->red.length, var->green.length, var->blue.length,
		var->transp.length);

	pr_debug("RGBT offset = %d:%d:%d:%d\n",
		var->red.offset, var->green.offset, var->blue.offset,
		var->transp.offset);

	return 0;
}

/*
 * imxfb_set_par():
 *	Set the user defined part of the display for the specified console
 */
static int imxfb_set_par(struct fb_info *info)
{
	struct imxfb_info *fbi = info->par;
	struct fb_var_screeninfo *var = &info->var;

	pr_debug("set_par\n");

	if (var->bits_per_pixel == 16)
		info->fix.visual = FB_VISUAL_TRUECOLOR;
	else if (!fbi->cmap_static)
		info->fix.visual = FB_VISUAL_PSEUDOCOLOR;
	else {
		/*
		 * Some people have weird ideas about wanting static
		 * pseudocolor maps.  I suspect their user space
		 * applications are broken.
		 */
		info->fix.visual = FB_VISUAL_STATIC_PSEUDOCOLOR;
	}

	info->fix.line_length = var->xres_virtual *
				  var->bits_per_pixel / 8;
	fbi->palette_size = var->bits_per_pixel == 8 ? 256 : 16;

	imxfb_activate_var(var, info);

	return 0;
}

static void imxfb_enable_controller(struct imxfb_info *fbi)
{
	pr_debug("Enabling LCD controller\n");

	/* initialize LCDC */
	LCDC_RMCR &= ~RMCR_LCDC_EN;		/* just to be safe... */

	LCDC_SSA	= fbi->screen_dma;
	/* physical screen start address	    */
	LCDC_VPW	= VPW_VPW(fbi->max_xres * fbi->max_bpp / 8 / 4);

	LCDC_POS	= 0x00000000;   /* panning offset 0 (0 pixel offset)        */

	/* disable hardware cursor */
	LCDC_CPOS	&= ~(CPOS_CC0 | CPOS_CC1);

	LCDC_RMCR = RMCR_LCDC_EN;

	if(fbi->backlight_power)
		fbi->backlight_power(1);
	if(fbi->lcd_power)
		fbi->lcd_power(1);
}

static void imxfb_disable_controller(struct imxfb_info *fbi)
{
	pr_debug("Disabling LCD controller\n");

	if(fbi->backlight_power)
		fbi->backlight_power(0);
	if(fbi->lcd_power)
		fbi->lcd_power(0);

	LCDC_RMCR = 0;
}

static int imxfb_blank(int blank, struct fb_info *info)
{
	struct imxfb_info *fbi = info->par;

	pr_debug("imxfb_blank: blank=%d\n", blank);

	switch (blank) {
	case FB_BLANK_POWERDOWN:
	case FB_BLANK_VSYNC_SUSPEND:
	case FB_BLANK_HSYNC_SUSPEND:
	case FB_BLANK_NORMAL:
		imxfb_disable_controller(fbi);
		break;

	case FB_BLANK_UNBLANK:
		imxfb_enable_controller(fbi);
		break;
	}
	return 0;
}

static struct fb_ops imxfb_ops = {
	.owner		= THIS_MODULE,
	.fb_check_var	= imxfb_check_var,
	.fb_set_par	= imxfb_set_par,
	.fb_setcolreg	= imxfb_setcolreg,
	.fb_fillrect	= cfb_fillrect,
	.fb_copyarea	= cfb_copyarea,
	.fb_imageblit	= cfb_imageblit,
	.fb_blank	= imxfb_blank,
};

/*
 * imxfb_activate_var():
 *	Configures LCD Controller based on entries in var parameter.  Settings are
 *	only written to the controller if changes were made.
 */
static int imxfb_activate_var(struct fb_var_screeninfo *var, struct fb_info *info)
{
	struct imxfb_info *fbi = info->par;
	pr_debug("var: xres=%d hslen=%d lm=%d rm=%d\n",
		var->xres, var->hsync_len,
		var->left_margin, var->right_margin);
	pr_debug("var: yres=%d vslen=%d um=%d bm=%d\n",
		var->yres, var->vsync_len,
		var->upper_margin, var->lower_margin);

#if DEBUG_VAR
	if (var->xres < 16        || var->xres > 1024)
		printk(KERN_ERR "%s: invalid xres %d\n",
			info->fix.id, var->xres);
	if (var->hsync_len < 1    || var->hsync_len > 64)
		printk(KERN_ERR "%s: invalid hsync_len %d\n",
			info->fix.id, var->hsync_len);
	if (var->left_margin > 255)
		printk(KERN_ERR "%s: invalid left_margin %d\n",
			info->fix.id, var->left_margin);
	if (var->right_margin > 255)
		printk(KERN_ERR "%s: invalid right_margin %d\n",
			info->fix.id, var->right_margin);
	if (var->yres < 1 || var->yres > 511)
		printk(KERN_ERR "%s: invalid yres %d\n",
			info->fix.id, var->yres);
	if (var->vsync_len > 100)
		printk(KERN_ERR "%s: invalid vsync_len %d\n",
			info->fix.id, var->vsync_len);
	if (var->upper_margin > 63)
		printk(KERN_ERR "%s: invalid upper_margin %d\n",
			info->fix.id, var->upper_margin);
	if (var->lower_margin > 255)
		printk(KERN_ERR "%s: invalid lower_margin %d\n",
			info->fix.id, var->lower_margin);
#endif