sa1100fb.c

S3C44B0X下的LCD （framebuffer）驱动资料与相关代码

#endif

	DPRINTK("DBAR1 = %p\n", DBAR1);
	DPRINTK("DBAR2 = %p\n", DBAR2);
	DPRINTK("LCCR0 = 0x%08x\n", LCCR0);
	DPRINTK("LCCR1 = 0x%08x\n", LCCR1);
	DPRINTK("LCCR2 = 0x%08x\n", LCCR2);
	DPRINTK("LCCR3 = 0x%08x\n", LCCR3);
}

static void sa1100fb_disable_controller(struct sa1100fb_info *fbi)
{
	DECLARE_WAITQUEUE(wait, current);

	DPRINTK("Disabling LCD controller\n");

#ifdef CONFIG_SA1100_GRAPHICSCLIENT
#error Where is GPIO24 set as an output?  Can we fit this in somewhere else?
	if (machine_is_graphicsclient()) {
		/*
		 * From ADS internal document:
		 *  GPIO24 should be LOW at least 10msec prior to disabling
		 *  the LCD interface.
		 *
		 * We'll wait 20msec.
		 */
		GPCR |= GPIO_GPIO24;
		set_current_state(TASK_UNINTERRUPTIBLE);
		schedule_timeout(20 * HZ / 1000);
	}
#endif
#ifdef CONFIG_SA1100_HUW_WEBPANEL
#error Move me into sa1100fb_power_up_lcd and/or sa1100fb_backlight_on
	if (machine_is_huw_webpanel()) {
		// dont forget to set the control lines to zero (?)
		DPRINTK("ShutDown HuW LCD controller\n");
		BCR_clear(BCR_TFT_ENA + BCR_CCFL_POW + BCR_PWM_BACKLIGHT);
	}
#endif

	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_LEN;	/* Disable LCD Controller */

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

/*
 *  sa1100fb_handle_irq: Handle 'LCD DONE' interrupts.
 */
static void sa1100fb_handle_irq(int irq, void *dev_id, struct pt_regs *regs)
{
	struct sa1100fb_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 sa1100fb_info *fbi, u_int state)
{
	u_int old_state;

	down(&fbi->ctrlr_sem);

	old_state = fbi->state;

	switch (state) {
	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;
			sa1100fb_disable_controller(fbi);
		}
		break;

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

			sa1100fb_backlight_off(fbi);
			if (old_state != C_DISABLE_CLKCHANGE)
				sa1100fb_disable_controller(fbi);
			sa1100fb_power_down_lcd(fbi);
		}
		break;

	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;
			sa1100fb_enable_controller(fbi);
		}
		break;

	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) {
			sa1100fb_disable_controller(fbi);
			sa1100fb_setup_gpio(fbi);
			sa1100fb_enable_controller(fbi);
		}
		break;

	case C_ENABLE:
		/*
		 * Power up the LCD screen, enable controller, and
		 * turn on the backlight.
		 */
		if (old_state != C_ENABLE) {
			fbi->state = C_ENABLE;
			sa1100fb_setup_gpio(fbi);
			sa1100fb_power_up_lcd(fbi);
			sa1100fb_enable_controller(fbi);
			sa1100fb_backlight_on(fbi);
		}
		break;
	}
	up(&fbi->ctrlr_sem);
}

/*
 * Our LCD controller task (which is called when we blank or unblank)
 * via keventd.
 */
static void sa1100fb_task(void *dummy)
{
	struct sa1100fb_info *fbi = dummy;
	u_int state = xchg(&fbi->task_state, -1);

	set_ctrlr_state(fbi, state);
}

#ifdef CONFIG_CPU_FREQ
/*
 * Calculate the minimum DMA period over all displays that we own.
 * This, together with the SDRAM bandwidth defines the slowest CPU
 * frequency that can be selected.
 */
static unsigned int sa1100fb_min_dma_period(struct sa1100fb_info *fbi)
{
	unsigned int min_period = (unsigned int)-1;
	int i;

	for (i = 0; i < MAX_NR_CONSOLES; i++) {
		unsigned int period;

		/*
		 * Do we own this display?
		 */
		if (fb_display[i].fb_info != &fbi->fb)
			continue;

		/*
		 * Ok, calculate its DMA period
		 */
		period = sa1100fb_display_dma_period(get_con_var(&fbi->fb, i));
		if (period < min_period)
			min_period = period;
	}

	return min_period;
}

/*
 * 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
sa1100fb_clkchg_notifier(struct notifier_block *nb, unsigned long val,
			 void *data)
{
	struct sa1100fb_info *fbi = TO_INF(nb, clockchg);
	struct cpufreq_minmax *mm = data;
	u_int pcd;

	switch (val) {
	case CPUFREQ_MINMAX:
		printk(KERN_DEBUG "min dma period: %d ps, old clock %d kHz, "
			"new clock %d kHz\n", sa1100fb_min_dma_period(fbi),
			mm->cur_freq, mm->new_freq);
		/* 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
sa1100fb_pm_callback(struct pm_dev *pm_dev, pm_request_t req, void *data)
{
	struct sa1100fb_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

/*
 * sa1100fb_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 sa1100fb_map_video_memory(struct sa1100fb_info *fbi)
{
	/*
	 * We reserve one page for the palette, plus the size
	 * of the framebuffer.
	 */
	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;
	}

	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 sa1100fb_info * __init sa1100fb_init_fbinfo(void)
{
	struct sa1100fb_mach_info *inf;
	struct sa1100fb_info *fbi;

	fbi = kmalloc(sizeof(struct sa1100fb_info) + sizeof(struct display) +
		      sizeof(u16) * 16, GFP_KERNEL);
	if (!fbi)
		return NULL;

	memset(fbi, 0, sizeof(struct sa1100fb_info) + sizeof(struct display));

	fbi->currcon		= -1;

	strcpy(fbi->fb.fix.id, SA1100_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, SA1100_NAME);
	strcpy(fbi->fb.fontname, "Acorn8x8");

	fbi->fb.fbops		= &sa1100fb_ops;
	fbi->fb.changevar	= NULL;
	fbi->fb.switch_con	= sa1100fb_switch;
	fbi->fb.updatevar	= sa1100fb_updatevar;
	fbi->fb.blank		= sa1100fb_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 = sa1100fb_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, sa1100fb_task, fbi);
	init_MUTEX(&fbi->ctrlr_sem);

	return fbi;
}

int __init sa1100fb_init(void)
{
	struct sa1100fb_info *fbi;
	int ret;

	fbi = sa1100fb_init_fbinfo();
	ret = -ENOMEM;
	if (!fbi)
		goto failed;

	/* Initialize video memory */
	ret = sa1100fb_map_video_memory(fbi);
	if (ret)
		goto failed;

	ret = request_irq(IRQ_LCD, sa1100fb_handle_irq, SA_INTERRUPT,
			  fbi->fb.fix.id, fbi);
	if (ret) {
		printk(KERN_ERR "sa1100fb: request_irq failed: %d\n", ret);
		goto failed;
	}

#ifdef ASSABET_PAL_VIDEO
	if (machine_is_assabet())
		ASSABET_BCR_clear(ASSABET_BCR_LCD_ON);
#endif

#ifdef CONFIG_SA1100_FREEBIRD
#error Please move this into sa1100fb_power_up_lcd
	if (machine_is_freebird()) {
		BCR_set(BCR_FREEBIRD_LCD_DISP);
		mdelay(20);
		BCR_set(BCR_FREEBIRD_LCD_PWR);
		mdelay(20);
	}
#endif

	sa1100fb_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, sa1100fb_pm_callback);
	if (fbi->pm)
		fbi->pm->data = fbi;
#endif
#ifdef CONFIG_CPU_FREQ
	fbi->clockchg.notifier_call = sa1100fb_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 sa1100fb_setup(char *options)
{
#if 0
	char *this_opt;

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

	while ((this_opt = strsep(&options, ",")) != 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(t