pxafb.c

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/*
 *  linux/drivers/video/pxafb.c
 *
 *  Copyright (C) 1999 Eric A. Thomas.
 *  Copyright (C) 2004 Jean-Frederic Clere.
 *  Copyright (C) 2004 Ian Campbell.
 *  Copyright (C) 2004 Jeff Lackey.
 *   Based on sa1100fb.c Copyright (C) 1999 Eric A. Thomas
 *  which in turn is
 *   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.
 *
 *	        Intel PXA250/210 LCD Controller Frame Buffer Driver
 *
 * Please direct your questions and comments on this driver to the following
 * email address:
 *
 *	[e-mail]
 *
 */

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/kernel.h>
#include <linux/sched.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 <linux/clk.h>
#include <linux/err.h>

#include <asm/hardware.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/div64.h>
#include <asm/arch/pxa-regs.h>
#include <asm/arch/bitfield.h>
#include <asm/arch/pxafb.h>

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

#include "pxafb.h"

/* Bits which should not be set in machine configuration structures */
#define LCCR0_INVALID_CONFIG_MASK (LCCR0_OUM|LCCR0_BM|LCCR0_QDM|LCCR0_DIS|LCCR0_EFM|LCCR0_IUM|LCCR0_SFM|LCCR0_LDM|LCCR0_ENB)
#define LCCR3_INVALID_CONFIG_MASK (LCCR3_HSP|LCCR3_VSP|LCCR3_PCD|LCCR3_BPP)

static void (*pxafb_backlight_power)(int);
static void (*pxafb_lcd_power)(int, struct fb_var_screeninfo *);

static int pxafb_activate_var(struct fb_var_screeninfo *var, struct pxafb_info *);
static void set_ctrlr_state(struct pxafb_info *fbi, u_int state);

#ifdef CONFIG_FB_PXA_PARAMETERS
#define PXAFB_OPTIONS_SIZE 256
static char g_options[PXAFB_OPTIONS_SIZE] __devinitdata = "";
#endif

static inline void pxafb_schedule_work(struct pxafb_info *fbi, u_int state)
{
	unsigned long flags;

	local_irq_save(flags);
	/*
	 * We need to handle two requests being made at the same time.
	 * There are two important cases:
	 *  1. When we are changing VT (C_REENABLE) while unblanking (C_ENABLE)
	 *     We must perform the unblanking, which will do our REENABLE for us.
	 *  2. When we are blanking, but immediately unblank before we have
	 *     blanked.  We do the "REENABLE" thing here as well, just to be sure.
	 */
	if (fbi->task_state == C_ENABLE && state == C_REENABLE)
		state = (u_int) -1;
	if (fbi->task_state == C_DISABLE && state == C_ENABLE)
		state = C_REENABLE;

	if (state != (u_int)-1) {
		fbi->task_state = state;
		schedule_work(&fbi->task);
	}
	local_irq_restore(flags);
}

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
pxafb_setpalettereg(u_int regno, u_int red, u_int green, u_int blue,
		       u_int trans, struct fb_info *info)
{
	struct pxafb_info *fbi = (struct pxafb_info *)info;
	u_int val;

	if (regno >= fbi->palette_size)
		return 1;

	if (fbi->fb.var.grayscale) {
		fbi->palette_cpu[regno] = ((blue >> 8) & 0x00ff);
		return 0;
	}

	switch (fbi->lccr4 & LCCR4_PAL_FOR_MASK) {
	case LCCR4_PAL_FOR_0:
		val  = ((red   >>  0) & 0xf800);
		val |= ((green >>  5) & 0x07e0);
		val |= ((blue  >> 11) & 0x001f);
		fbi->palette_cpu[regno] = val;
		break;
	case LCCR4_PAL_FOR_1:
		val  = ((red   << 8) & 0x00f80000);
		val |= ((green >> 0) & 0x0000fc00);
		val |= ((blue  >> 8) & 0x000000f8);
		((u32*)(fbi->palette_cpu))[regno] = val;
		break;
	case LCCR4_PAL_FOR_2:
		val  = ((red   << 8) & 0x00fc0000);
		val |= ((green >> 0) & 0x0000fc00);
		val |= ((blue  >> 8) & 0x000000fc);
		((u32*)(fbi->palette_cpu))[regno] = val;
		break;
	}

	return 0;
}

static int
pxafb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
		   u_int trans, struct fb_info *info)
{
	struct pxafb_info *fbi = (struct pxafb_info *)info;
	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 matter what visual we are using.
	 */
	if (fbi->fb.var.grayscale)
		red = green = blue = (19595 * red + 38470 * green +
					7471 * blue) >> 16;

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

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

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

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

	return ret;
}

/*
 *  pxafb_bpp_to_lccr3():
 *    Convert a bits per pixel value to the correct bit pattern for LCCR3
 */
static int pxafb_bpp_to_lccr3(struct fb_var_screeninfo *var)
{
        int ret = 0;
        switch (var->bits_per_pixel) {
        case 1:  ret = LCCR3_1BPP; break;
        case 2:  ret = LCCR3_2BPP; break;
        case 4:  ret = LCCR3_4BPP; break;
        case 8:  ret = LCCR3_8BPP; break;
        case 16: ret = LCCR3_16BPP; break;
        }
        return ret;
}

#ifdef CONFIG_CPU_FREQ
/*
 *  pxafb_display_dma_period()
 *    Calculate the minimum period (in picoseconds) between two DMA
 *    requests for the LCD controller.  If we hit this, it means we're
 *    doing nothing but LCD DMA.
 */
static unsigned int pxafb_display_dma_period(struct fb_var_screeninfo *var)
{
       /*
        * Period = pixclock * bits_per_byte * bytes_per_transfer
        *              / memory_bits_per_pixel;
        */
       return var->pixclock * 8 * 16 / var->bits_per_pixel;
}

extern unsigned int get_clk_frequency_khz(int info);
#endif

/*
 * Select the smallest mode that allows the desired resolution to be
 * displayed. If desired parameters can be rounded up.
 */
static struct pxafb_mode_info *pxafb_getmode(struct pxafb_mach_info *mach, struct fb_var_screeninfo *var)
{
	struct pxafb_mode_info *mode = NULL;
	struct pxafb_mode_info *modelist = mach->modes;
	unsigned int best_x = 0xffffffff, best_y = 0xffffffff;
	unsigned int i;

	for (i = 0 ; i < mach->num_modes ; i++) {
		if (modelist[i].xres >= var->xres && modelist[i].yres >= var->yres &&
				modelist[i].xres < best_x && modelist[i].yres < best_y &&
				modelist[i].bpp >= var->bits_per_pixel ) {
			best_x = modelist[i].xres;
			best_y = modelist[i].yres;
			mode = &modelist[i];
		}
	}

	return mode;
}

static void pxafb_setmode(struct fb_var_screeninfo *var, struct pxafb_mode_info *mode)
{
	var->xres		= mode->xres;
	var->yres		= mode->yres;
	var->bits_per_pixel	= mode->bpp;
	var->pixclock		= mode->pixclock;
	var->hsync_len		= mode->hsync_len;
	var->left_margin	= mode->left_margin;
	var->right_margin	= mode->right_margin;
	var->vsync_len		= mode->vsync_len;
	var->upper_margin	= mode->upper_margin;
	var->lower_margin	= mode->lower_margin;
	var->sync		= mode->sync;
	var->grayscale		= mode->cmap_greyscale;
	var->xres_virtual 	= var->xres;
	var->yres_virtual	= var->yres;
}

/*
 *  pxafb_check_var():
 *    Get the video params out of 'var'. If a value doesn't fit, round it up,
 *    if it's too big, return -EINVAL.
 *
 *    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 pxafb_check_var(struct fb_var_screeninfo *var, struct fb_info *info)
{
	struct pxafb_info *fbi = (struct pxafb_info *)info;
	struct pxafb_mach_info *inf = fbi->dev->platform_data;

	if (var->xres < MIN_XRES)
		var->xres = MIN_XRES;
	if (var->yres < MIN_YRES)
		var->yres = MIN_YRES;

	if (inf->fixed_modes) {
		struct pxafb_mode_info *mode;

		mode = pxafb_getmode(inf, var);
		if (!mode)
			return -EINVAL;
		pxafb_setmode(var, mode);
	} else {
		if (var->xres > inf->modes->xres)
			return -EINVAL;
		if (var->yres > inf->modes->yres)
			return -EINVAL;
		if (var->bits_per_pixel > inf->modes->bpp)
			return -EINVAL;
	}

	var->xres_virtual =
		max(var->xres_virtual, var->xres);
	var->yres_virtual =
		max(var->yres_virtual, var->yres);

        /*
	 * Setup the RGB parameters for this display.
	 *
	 * The pixel packing format is described on page 7-11 of the
	 * PXA2XX Developer's Manual.
         */
	if (var->bits_per_pixel == 16) {
		var->red.offset   = 11; var->red.length   = 5;
		var->green.offset = 5;  var->green.length = 6;
		var->blue.offset  = 0;  var->blue.length  = 5;
		var->transp.offset = var->transp.length = 0;
	} else {
		var->red.offset = var->green.offset = var->blue.offset = var->transp.offset = 0;
		var->red.length   = 8;
		var->green.length = 8;
		var->blue.length  = 8;
		var->transp.length = 0;
	}

#ifdef CONFIG_CPU_FREQ
	pr_debug("pxafb: dma period = %d ps, clock = %d kHz\n",
		 pxafb_display_dma_period(var),
		 get_clk_frequency_khz(0));
#endif

	return 0;
}

static inline void pxafb_set_truecolor(u_int is_true_color)
{
	pr_debug("pxafb: true_color = %d\n", is_true_color);
	// do your machine-specific setup if needed
}

/*
 * pxafb_set_par():
 *	Set the user defined part of the display for the specified console
 */
static int pxafb_set_par(struct fb_info *info)
{
	struct pxafb_info *fbi = (struct pxafb_info *)info;
	struct fb_var_screeninfo *var = &info->var;
	unsigned long palette_mem_size;

	pr_debug("pxafb: set_par\n");

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

	fbi->fb.fix.line_length = var->xres_virtual *
				  var->bits_per_pixel / 8;
	if (var->bits_per_pixel == 16)
		fbi->palette_size = 0;
	else
		fbi->palette_size = var->bits_per_pixel == 1 ? 4 : 1 << var->bits_per_pixel;

	if ((fbi->lccr4 & LCCR4_PAL_FOR_MASK) == LCCR4_PAL_FOR_0)
		palette_mem_size = fbi->palette_size * sizeof(u16);
	else
		palette_mem_size = fbi->palette_size * sizeof(u32);

	pr_debug("pxafb: palette_mem_size = 0x%08lx\n", palette_mem_size);

	fbi->palette_cpu = (u16 *)(fbi->map_cpu + PAGE_SIZE - palette_mem_size);
	fbi->palette_dma = fbi->map_dma + PAGE_SIZE - palette_mem_size;

	/*
	 * Set (any) board control register to handle new color depth
	 */
	pxafb_set_truecolor(fbi->fb.fix.visual == FB_VISUAL_TRUECOLOR);

	if (fbi->fb.var.bits_per_pixel == 16)
		fb_dealloc_cmap(&fbi->fb.cmap);
	else
		fb_alloc_cmap(&fbi->fb.cmap, 1<<fbi->fb.var.bits_per_pixel, 0);

	pxafb_activate_var(var, fbi);

	return 0;
}

/*
 * Formal definition of the VESA spec:
 *  On
 *  	This refers to the state of the display when it is in full operation
 *  Stand-By
 *  	This defines an optional operating state of minimal power reduction with
 *  	the shortest recovery time
 *  Suspend
 *  	This refers to a level of power management in which substantial power
 *  	reduction is achieved by the display.  The display can have a longer
 *  	recovery time from this state than from the Stand-by state
 *  Off
 *  	This indicates that the display is consuming the lowest level of power
 *  	and is non-operational. Recovery from this state may optionally require
 *  	the user to manually power on the monitor
 *
 *  Now, the fbdev driver adds an additional state, (blank), where they
 *  turn off the video (maybe by colormap tricks), but don't mess with the
 *  video itself: think of it semantically between on and Stand-By.
 *
 *  So here's what we should do in our fbdev blank routine:
 *
 *  	VESA_NO_BLANKING (mode 0)	Video on,  front/back light on
 *  	VESA_VSYNC_SUSPEND (mode 1)  	Video on,  front/back light off
 *  	VESA_HSYNC_SUSPEND (mode 2)  	Video on,  front/back light off
 *  	VESA_POWERDOWN (mode 3)		Video off, front/back light off
 *
 *  This will match the matrox implementation.
 */

/*
 * pxafb_blank():
 *	Blank the display by setting all palette values to zero.  Note, the
 * 	16 bpp mode does not really use the palette, so this will not
 *      blank the display in all modes.
 */
static int pxafb_blank(int blank, struct fb_info *info)
{
	struct pxafb_info *fbi = (struct pxafb_info *)info;
	int i;

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

	switch (blank) {
	case FB_BLANK_POWERDOWN:
	case FB_BLANK_VSYNC_SUSPEND:
	case FB_BLANK_HSYNC_SUSPEND:
	case FB_BLANK_NORMAL:
		if (fbi->fb.fix.visual == FB_VISUAL_PSEUDOCOLOR ||
		    fbi->fb.fix.visual == FB_VISUAL_STATIC_PSEUDOCOLOR)
			for (i = 0; i < fbi->palette_size; i++)
				pxafb_setpalettereg(i, 0, 0, 0, 0, info);

		pxafb_schedule_work(fbi, C_DISABLE);
		//TODO if (pxafb_blank_helper) pxafb_blank_helper(blank);
		break;

	case FB_BLANK_UNBLANK:
		//TODO if (pxafb_blank_helper) pxafb_blank_helper(blank);
		if (fbi->fb.fix.visual == FB_VISUAL_PSEUDOCOLOR ||
		    fbi->fb.fix.visual == FB_VISUAL_STATIC_PSEUDOCOLOR)
			fb_set_cmap(&fbi->fb.cmap, info);
		pxafb_schedule_work(fbi, C_ENABLE);
	}
	return 0;
}

static int pxafb_mmap(struct fb_info *info,
		      struct vm_area_struct *vma)
{
	struct pxafb_info *fbi = (struct pxafb_info *)info;
	unsigned long off = vma->vm_pgoff << PAGE_SHIFT;

	if (off < info->fix.smem_len) {
		vma->vm_pgoff += 1;
		return dma_mmap_writecombine(fbi->dev, vma, fbi->map_cpu,
					     fbi->map_dma, fbi->map_size);
	}
	return -EINVAL;
}

static struct fb_ops pxafb_ops = {
	.owner		= THIS_MODULE,
	.fb_check_var	= pxafb_check_var,
	.fb_set_par	= pxafb_set_par,
	.fb_setcolreg	= pxafb_setcolreg,
	.fb_fillrect	= cfb_fillrect,
	.fb_copyarea	= cfb_copyarea,
	.fb_imageblit	= cfb_imageblit,
	.fb_blank	= pxafb_blank,
	.fb_mmap	= pxafb_mmap,
};

/*
 * Calculate the PCD value from the clock rate (in picoseconds).
 * We take account of the PPCR clock setting.
 * From PXA Developer's Manual:
 *
 *   PixelClock =      LCLK
 *                -------------