imxfb.c

Linux环境下视频显示卡设备的驱动程序源代码

/*
 *  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]
 */


#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/mm.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 <linux/io.h>

#include <mach/imxfb.h>

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

#define DRIVER_NAME "imx-fb"

#define LCDC_SSA	0x00

#define LCDC_SIZE	0x04
#define SIZE_XMAX(x)	((((x) >> 4) & 0x3f) << 20)
#define SIZE_YMAX(y)	((y) & 0x1ff)

#define LCDC_VPW	0x08
#define VPW_VPW(x)	((x) & 0x3ff)

#define LCDC_CPOS	0x0C
#define CPOS_CC1	(1<<31)
#define CPOS_CC0	(1<<30)
#define CPOS_OP		(1<<28)
#define CPOS_CXP(x)	(((x) & 3ff) << 16)
#define CPOS_CYP(y)	((y) & 0x1ff)

#define LCDC_LCWHB	0x10
#define LCWHB_BK_EN	(1<<31)
#define LCWHB_CW(w)	(((w) & 0x1f) << 24)
#define LCWHB_CH(h)	(((h) & 0x1f) << 16)
#define LCWHB_BD(x)	((x) & 0xff)

#define LCDC_LCHCC	0x14
#define LCHCC_CUR_COL_R(r) (((r) & 0x1f) << 11)
#define LCHCC_CUR_COL_G(g) (((g) & 0x3f) << 5)
#define LCHCC_CUR_COL_B(b) ((b) & 0x1f)

#define LCDC_PCR	0x18

#define LCDC_HCR	0x1C
#define HCR_H_WIDTH(x)	(((x) & 0x3f) << 26)
#define HCR_H_WAIT_1(x)	(((x) & 0xff) << 8)
#define HCR_H_WAIT_2(x)	((x) & 0xff)

#define LCDC_VCR	0x20
#define VCR_V_WIDTH(x)	(((x) & 0x3f) << 26)
#define VCR_V_WAIT_1(x)	(((x) & 0xff) << 8)
#define VCR_V_WAIT_2(x)	((x) & 0xff)

#define LCDC_POS	0x24
#define POS_POS(x)	((x) & 1f)

#define LCDC_LSCR1	0x28
/* bit fields in imxfb.h */

#define LCDC_PWMR	0x2C
/* bit fields in imxfb.h */

#define LCDC_DMACR	0x30
/* bit fields in imxfb.h */

#define LCDC_RMCR	0x34
#define RMCR_LCDC_EN	(1<<1)
#define RMCR_SELF_REF	(1<<0)

#define LCDC_LCDICR	0x38
#define LCDICR_INT_SYN	(1<<2)
#define LCDICR_INT_CON	(1)

#define LCDC_LCDISR	0x40
#define LCDISR_UDR_ERR	(1<<3)
#define LCDISR_ERR_RES	(1<<2)
#define LCDISR_EOF	(1<<1)
#define LCDISR_BOF	(1<<0)

/*
 * These are the bitfields for each
 * display depth that we support.
 */
struct imxfb_rgb {
	struct fb_bitfield	red;
	struct fb_bitfield	green;
	struct fb_bitfield	blue;
	struct fb_bitfield	transp;
};

struct imxfb_info {
	struct platform_device  *pdev;
	void __iomem		*regs;

	u_int			max_bpp;
	u_int			max_xres;
	u_int			max_yres;

	/*
	 * These are the addresses we mapped
	 * the framebuffer memory region to.
	 */
	dma_addr_t		map_dma;
	u_char			*map_cpu;
	u_int			map_size;

	u_char			*screen_cpu;
	dma_addr_t		screen_dma;
	u_int			palette_size;

	dma_addr_t		dbar1;
	dma_addr_t		dbar2;

	u_int			pcr;
	u_int			pwmr;
	u_int			lscr1;
	u_int			dmacr;
	u_int			cmap_inverse:1,
				cmap_static:1,
				unused:30;

	void (*lcd_power)(int);
	void (*backlight_power)(int);
};

#define IMX_NAME	"IMX"

/*
 * Minimum X and Y resolutions
 */
#define MIN_XRES	64
#define MIN_YRES	64

static struct imxfb_rgb def_rgb_16_tft = {
	.red	= {.offset = 11, .length = 5,},
	.green	= {.offset = 5, .length = 6,},
	.blue	= {.offset = 0, .length = 5,},
	.transp = {.offset = 0, .length = 0,},
};

static struct imxfb_rgb def_rgb_16_stn = {
	.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;
}

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);

		writel(val, fbi->regs + 0x800 + (regno << 2));
		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;
	struct imxfb_rgb *rgb;

	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:
	default:
		if (readl(fbi->regs + LCDC_PCR) & PCR_TFT)
			rgb = &def_rgb_16_tft;
		else
			rgb = &def_rgb_16_stn;
		break;
	case 8:
		rgb = &def_rgb_8;
		break;
	}

	/*
	 * Copy the RGB parameters for this display
	 * from the machine specific parameters.
	 */
	var->red    = rgb->red;
	var->green  = rgb->green;
	var->blue   = rgb->blue;
	var->transp = rgb->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 */
	writel(readl(fbi->regs + LCDC_RMCR) & ~RMCR_LCDC_EN,
		fbi->regs + LCDC_RMCR);	/* just to be safe... */

	writel(fbi->screen_dma, fbi->regs + LCDC_SSA);

	/* physical screen start address	    */
	writel(VPW_VPW(fbi->max_xres * fbi->max_bpp / 8 / 4),
		fbi->regs + LCDC_VPW);

	/* panning offset 0 (0 pixel offset)        */
	writel(0x00000000, fbi->regs + LCDC_POS);

	/* disable hardware cursor */
	writel(readl(fbi->regs + LCDC_CPOS) & ~(CPOS_CC0 | CPOS_CC1),
		fbi->regs + LCDC_CPOS);

	writel(RMCR_LCDC_EN, fbi->regs + LCDC_RMCR);