pxafb.c

LINUX下PXA的LCD驱动程序原代码,值得一看,

	 * setup is based on type of panel supported
	 */

	lccr0 = fbi->lccr0;

	/* 4 bit interface */
	if ((lccr0 & LCCR0_CMS) && (lccr0 & LCCR0_SDS) && !(lccr0 & LCCR0_DPD))
	{
		// bits 58-61
		GPDR1 |= (0xf << 26);
		GAFR1_U = (GAFR1_U & ~(0xff << 20)) | (0xaa << 20);

		// bits 74-77
		GPDR2 |= (0xf << 10);
                GAFR2_L = (GAFR2_L & ~(0xff << 20)) | (0xaa << 20);
	}

        /* 8 bit interface */
        else if (((lccr0 & LCCR0_CMS) && ((lccr0 & LCCR0_SDS) || (lccr0 & LCCR0_DPD))) ||
                 (!(lccr0 & LCCR0_CMS) && !(lccr0 & LCCR0_PAS) && !(lccr0 & LCCR0_SDS)))
        {
		// bits 58-65
                GPDR1 |= (0x3f << 26);
                GPDR2 |= (0x3);

                GAFR1_U = (GAFR1_U & ~(0xfff << 20)) | (0xaaa << 20);
                GAFR2_L = (GAFR2_L & ~0xf) | (0xa);

                // bits 74-77
                GPDR2 |= (0xf << 10);
                GAFR2_L = (GAFR2_L & ~(0xff << 20)) | (0xaa << 20);
        }

        /* 16 bit interface */
        else if (!(lccr0 & LCCR0_CMS) && ((lccr0 & LCCR0_SDS) || (lccr0 & LCCR0_PAS)))
        {
		// bits 58-77
                GPDR1 |= (0x3f << 26);
                GPDR2 |= 0x00003fff;

                GAFR1_U = (GAFR1_U & ~(0xfff << 20)) | (0xaaa << 20);
                GAFR2_L = (GAFR2_L & 0xf0000000) | 0x0aaaaaaa;
        }
	else
	{
		printk( KERN_ERR "pxafb_setup_gpio: unable to determine bits per pixel\n");
	}
}

static void pxafb_enable_controller(struct pxafb_info *fbi)
{
	DPRINTK("Enabling LCD controller\n");

	/* Sequence from 11.7.10 */
	LCCR3 = fbi->reg_lccr3;
	LCCR2 = fbi->reg_lccr2;
	LCCR1 = fbi->reg_lccr1;
	LCCR0 = fbi->reg_lccr0 & ~LCCR0_ENB;

	/* FIXME we used to have LCD power control here */

	FDADR0 = fbi->fdadr0;
	FDADR1 = fbi->fdadr1;
	LCCR0 |= LCCR0_ENB;

	DPRINTK("FDADR0 = 0x%08x\n", (unsigned int)FDADR0);
	DPRINTK("FDADR1 = 0x%08x\n", (unsigned int)FDADR1);
	DPRINTK("LCCR0 = 0x%08x\n", (unsigned int)LCCR0);
	DPRINTK("LCCR1 = 0x%08x\n", (unsigned int)LCCR1);
	DPRINTK("LCCR2 = 0x%08x\n", (unsigned int)LCCR2);
	DPRINTK("LCCR3 = 0x%08x\n", (unsigned int)LCCR3);
}

static void pxafb_disable_controller(struct pxafb_info *fbi)
{
	DECLARE_WAITQUEUE(wait, current);

	DPRINTK("Disabling LCD controller\n");

	/* FIXME add power down GPIO stuff here */

	add_wait_queue(&fbi->ctrlr_wait, &wait);
	set_current_state(TASK_UNINTERRUPTIBLE);

	LCSR = 0xffffffff;	/* Clear LCD Status Register */
//	LCCR0 &= ~LCCR0_LDM;	/* Enable LCD Disable Done Interrupt */
//	enable_irq(IRQ_LCD);	/* Enable LCD IRQ */
	LCCR0 &= ~LCCR0_ENB;	/* Disable LCD Controller */

	schedule_timeout(20 * HZ / 1000);
	current->state = TASK_RUNNING;
	remove_wait_queue(&fbi->ctrlr_wait, &wait);
}

/*
 *  pxafb_handle_irq: Handle 'LCD DONE' interrupts.
 */
static void pxafb_handle_irq(int irq, void *dev_id, struct pt_regs *regs)
{
	struct pxafb_info *fbi = dev_id;
	unsigned int lcsr = LCSR;

	if (lcsr & LCSR_LDD) {
		LCCR0 |= LCCR0_LDM;
		wake_up(&fbi->ctrlr_wait);
	}

	LCSR = lcsr;
}

/*
 * This function must be called from task context only, since it will
 * sleep when disabling the LCD controller, or if we get two contending
 * processes trying to alter state.
 */
static void set_ctrlr_state(struct pxafb_info *fbi, u_int state)
{
	u_int old_state;

	down(&fbi->ctrlr_sem);

	old_state = fbi->state;

	switch (state) {
#if 0
	case C_DISABLE_CLKCHANGE:
		/*
		 * Disable controller for clock change.  If the
		 * controller is already disabled, then do nothing.
		 */
		if (old_state != C_DISABLE) {
			fbi->state = state;
			pxafb_disable_controller(fbi);
		}
		break;

	case C_DISABLE:
		/*
		 * Disable controller
		 */
		if (old_state != C_DISABLE) {
			fbi->state = state;

			pxafb_backlight_off(fbi);
			if (old_state != C_DISABLE_CLKCHANGE)
				pxafb_disable_controller(fbi);
			pxafb_power_down_lcd(fbi);
		}
		break;
#endif
	case C_ENABLE_CLKCHANGE:
		/*
		 * Enable the controller after clock change.  Only
		 * do this if we were disabled for the clock change.
		 */
		if (old_state == C_DISABLE_CLKCHANGE) {
			fbi->state = C_ENABLE;
			pxafb_enable_controller(fbi);
		}
		break;
#if 0
	case C_REENABLE:
		/*
		 * Re-enable the controller only if it was already
		 * enabled.  This is so we reprogram the control
		 * registers.
		 */
		if (old_state == C_ENABLE) {
			pxafb_disable_controller(fbi);
			pxafb_setup_gpio(fbi);
			pxafb_enable_controller(fbi);
		}
		break;
#endif
	case C_ENABLE:
		/*
		 * Power up the LCD screen, enable controller, and
		 * turn on the backlight.
		 */
		if (old_state != C_ENABLE) {
			fbi->state = C_ENABLE;
			pxafb_setup_gpio(fbi);
			pxafb_power_up_lcd(fbi);
			pxafb_enable_controller(fbi);
			pxafb_backlight_on(fbi);
		}
		break;
	}
	up(&fbi->ctrlr_sem);
}

/*
 * Our LCD controller task (which is called when we blank or unblank)
 * via keventd.
 */
static void pxafb_task(void *dummy)
{
	struct pxafb_info *fbi = dummy;
	u_int state = xchg(&fbi->task_state, -1);

	set_ctrlr_state(fbi, state);
}

#ifdef CONFIG_CPU_FREQ
/*
 * CPU clock speed change handler.  We need to adjust the LCD timing
 * parameters when the CPU clock is adjusted by the power management
 * subsystem.
 */
static int
pxafb_clkchg_notifier(struct notifier_block *nb, unsigned long val,
			 void *data)
{
	struct pxafb_info *fbi = TO_INF(nb, clockchg);
	u_int pcd;

	switch (val) {
	case CPUFREQ_MINMAX:
		/* todo: fill in min/max values */
		break;

	case CPUFREQ_PRECHANGE:
		set_ctrlr_state(fbi, C_DISABLE_CLKCHANGE);
		break;

	case CPUFREQ_POSTCHANGE:
		pcd = get_pcd(fbi->fb.var.pixclock);
		fbi->reg_lccr3 = (fbi->reg_lccr3 & ~0xff) | LCCR3_PixClkDiv(pcd);
		set_ctrlr_state(fbi, C_ENABLE_CLKCHANGE);
		break;
	}
	return 0;
}
#endif

#ifdef CONFIG_PM
/*
 * Power management hook.  Note that we won't be called from IRQ context,
 * unlike the blank functions above, so we may sleep.
 */
static int
pxafb_pm_callback(struct pm_dev *pm_dev, pm_request_t req, void *data)
{
	struct pxafb_info *fbi = pm_dev->data;

	DPRINTK("pm_callback: %d\n", req);

	if (req == PM_SUSPEND || req == PM_RESUME) {
		int state = (int)data;

		if (state == 0) {
			/* Enter D0. */
			set_ctrlr_state(fbi, C_ENABLE);
		} else {
			/* Enter D1-D3.  Disable the LCD controller.  */
			set_ctrlr_state(fbi, C_DISABLE);
		}
	}
	DPRINTK("done\n");
	return 0;
}
#endif

/*
 * pxafb_map_video_memory():
 *      Allocates the DRAM memory for the frame buffer.  This buffer is  
 *	remapped into a non-cached, non-buffered, memory region to  
 *      allow palette and pixel writes to occur without flushing the 
 *      cache.  Once this area is remapped, all virtual memory
 *      access to the video memory should occur at the new region.
 */
static int __init pxafb_map_video_memory(struct pxafb_info *fbi)
{
	u_long palette_mem_size;

	/*
	 * We reserve one page for the palette, plus the size
	 * of the framebuffer.
	 *
	 * layout of stuff in memory
	 *
	 *                fblow descriptor
	 *                fbhigh descriptor
	 *                palette descriptor
	 *                palette
	 *   page boundary->
	 *                frame buffer
	 */
	fbi->map_size = PAGE_ALIGN(fbi->fb.fix.smem_len + PAGE_SIZE);
	fbi->map_cpu = consistent_alloc(GFP_KERNEL, fbi->map_size,
					&fbi->map_dma);

	if (fbi->map_cpu) {
		fbi->screen_cpu = fbi->map_cpu + PAGE_SIZE;
		fbi->screen_dma = fbi->map_dma + PAGE_SIZE;
		fbi->fb.fix.smem_start = fbi->screen_dma;

		fbi->palette_size = fbi->fb.var.bits_per_pixel == 8 ? 256 : 16;

		palette_mem_size = fbi->palette_size * sizeof(u16);

		DPRINTK("palette_mem_size = 0x%08lx\n", (u_long) 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;

	}

	return fbi->map_cpu ? 0 : -ENOMEM;
}

/* Fake monspecs to fill in fbinfo structure */
static struct fb_monspecs monspecs __initdata = {
	30000, 70000, 50, 65, 0	/* Generic */
};


static struct pxafb_info * __init pxafb_init_fbinfo(void)
{
	struct pxafb_mach_info *inf;
	struct pxafb_info *fbi;

	fbi = kmalloc(sizeof(struct pxafb_info) + sizeof(struct display) +
		      sizeof(u16) * 16, GFP_KERNEL);
	if (!fbi)
		return NULL;

	memset(fbi, 0, sizeof(struct pxafb_info) + sizeof(struct display));

	fbi->currcon		= -1;

	strcpy(fbi->fb.fix.id, PXA_NAME);

	fbi->fb.fix.type	= FB_TYPE_PACKED_PIXELS;
	fbi->fb.fix.type_aux	= 0;
	fbi->fb.fix.xpanstep	= 0;
	fbi->fb.fix.ypanstep	= 0;
	fbi->fb.fix.ywrapstep	= 0;
	fbi->fb.fix.accel	= FB_ACCEL_NONE;

	fbi->fb.var.nonstd	= 0;
	fbi->fb.var.activate	= FB_ACTIVATE_NOW;
	fbi->fb.var.height	= -1;
	fbi->fb.var.width	= -1;
	fbi->fb.var.accel_flags	= 0;
	fbi->fb.var.vmode	= FB_VMODE_NONINTERLACED;

	strcpy(fbi->fb.modename, PXA_NAME);
	strcpy(fbi->fb.fontname, "Acorn8x8");

	fbi->fb.fbops		= &pxafb_ops;
	fbi->fb.changevar	= NULL;
	fbi->fb.switch_con	= pxafb_switch;
	fbi->fb.updatevar	= pxafb_updatevar;
	fbi->fb.blank		= pxafb_blank;
	fbi->fb.flags		= FBINFO_FLAG_DEFAULT;
	fbi->fb.node		= -1;
	fbi->fb.monspecs	= monspecs;
	fbi->fb.disp		= (struct display *)(fbi + 1);
	fbi->fb.pseudo_palette	= (void *)(fbi->fb.disp + 1);

	fbi->rgb[RGB_8]		= &rgb_8;
	fbi->rgb[RGB_16]	= &def_rgb_16;

	inf = pxafb_get_machine_info(fbi);

	fbi->max_xres			= inf->xres;
	fbi->fb.var.xres		= inf->xres;
	fbi->fb.var.xres_virtual	= inf->xres;
	fbi->max_yres			= inf->yres;
	fbi->fb.var.yres		= inf->yres;
	fbi->fb.var.yres_virtual	= inf->yres;
	fbi->max_bpp			= inf->bpp;
	fbi->fb.var.bits_per_pixel	= inf->bpp;
	fbi->fb.var.pixclock		= inf->pixclock;
	fbi->fb.var.hsync_len		= inf->hsync_len;
	fbi->fb.var.left_margin		= inf->left_margin;
	fbi->fb.var.right_margin	= inf->right_margin;
	fbi->fb.var.vsync_len		= inf->vsync_len;
	fbi->fb.var.upper_margin	= inf->upper_margin;
	fbi->fb.var.lower_margin	= inf->lower_margin;
	fbi->fb.var.sync		= inf->sync;
	fbi->fb.var.grayscale		= inf->cmap_greyscale;
	fbi->cmap_inverse		= inf->cmap_inverse;
	fbi->cmap_static		= inf->cmap_static;
	fbi->lccr0			= inf->lccr0;
	fbi->lccr3			= inf->lccr3;
	fbi->state			= C_DISABLE;
	fbi->task_state			= (u_char)-1;
	fbi->fb.fix.smem_len		= fbi->max_xres * fbi->max_yres *
					  fbi->max_bpp / 8;

	init_waitqueue_head(&fbi->ctrlr_wait);
	INIT_TQUEUE(&fbi->task, pxafb_task, fbi);
	init_MUTEX(&fbi->ctrlr_sem);

	return fbi;
}

int __init pxafb_init(void)
{
	struct pxafb_info *fbi;
	int ret;

	printk("PXA LCD FrameBuffer Driver modified by Michael <[e-mail]>\n");
	fbi = pxafb_init_fbinfo();
	ret = -ENOMEM;
	if (!fbi)
		goto failed;

	/* Initialize video memory */
	ret = pxafb_map_video_memory(fbi);
	if (ret)
		goto failed;

//	ret = request_irq(IRQ_LCD, pxafb_handle_irq, SA_INTERRUPT,
//			  "LCD", fbi);
//	if (ret) {
//		printk(KERN_ERR "pxafb: failed in request_irq: %d\n", ret);
//		goto failed;
//	}

	pxafb_set_var(&fbi->fb.var, -1, &fbi->fb);

	ret = register_framebuffer(&fbi->fb);
	if (ret < 0)
		goto failed;

#ifdef CONFIG_PM
	/*
	 * Note that the console registers this as well, but we want to
	 * power down the display prior to sleeping.
	 */
	fbi->pm = pm_register(PM_SYS_DEV, PM_SYS_VGA, pxafb_pm_callback);
	if (fbi->pm)
		fbi->pm->data = fbi;
#endif
#ifdef CONFIG_CPU_FREQ
	fbi->clockchg.notifier_call = pxafb_clkchg_notifier;
	cpufreq_register_notifier(&fbi->clockchg);
#endif

	/*
	 * Ok, now enable the LCD controller
	 */
	set_ctrlr_state(fbi, C_ENABLE);

	/* This driver cannot be unloaded at the moment */
	MOD_INC_USE_COUNT;

	return 0;

failed:
	if (fbi)
		kfree(fbi);
	return ret;
}

int __init pxafb_setup(char *options)
{
#if 0
	char *this_opt;

	if (!options || !*options)
		return 0;

	for (this_opt = strtok(options, ","); this_opt;
	     this_opt = strtok(NULL, ",")) {

		if (!strncmp(this_opt, "bpp:", 4))
			current_par.max_bpp =
			    simple_strtoul(this_opt + 4, NULL, 0);

		if (!strncmp(this_opt, "lccr0:", 6))
			lcd_shadow.lccr0 =
			    simple_strtoul(this_opt + 6, NULL, 0);
		if (!strncmp(this_opt, "lccr1:", 6)) {
			lcd_shadow.lccr1 =
			    simple_strtoul(this_opt + 6, NULL, 0);
			current_par.max_xres =
			    (lcd_shadow.lccr1 & 0x3ff) + 16;
		}
		if (!strncmp(this_opt, "lccr2:", 6)) {
			lcd_shadow.lccr2 =
			    simple_strtoul(this_opt + 6, NULL, 0);
			current_par.max_yres =
			    (lcd_shadow.
			     lccr0 & LCCR0_SDS) ? ((lcd_shadow.
						    lccr2 & 0x3ff) +
						   1) *
			    2 : ((lcd_shadow.lccr2 & 0x3ff) + 1);
		}
		if (!strncmp(this_opt, "lccr3:", 6))
			lcd_shadow.lccr3 =
			    simple_strtoul(this_opt + 6, NULL, 0);
	}
#endif
	return 0;

}