xref: /linux/drivers/video/fbdev/atmel_lcdfb.c (revision cbac924200b838cfb8d8b1415113d788089dc50b)
1 /*
2  *  Driver for AT91 LCD Controller
3  *
4  *  Copyright (C) 2007 Atmel Corporation
5  *
6  * This file is subject to the terms and conditions of the GNU General Public
7  * License.  See the file COPYING in the main directory of this archive for
8  * more details.
9  */
10 
11 #include <linux/kernel.h>
12 #include <linux/platform_device.h>
13 #include <linux/dma-mapping.h>
14 #include <linux/interrupt.h>
15 #include <linux/clk.h>
16 #include <linux/fb.h>
17 #include <linux/init.h>
18 #include <linux/delay.h>
19 #include <linux/backlight.h>
20 #include <linux/gfp.h>
21 #include <linux/gpio/consumer.h>
22 #include <linux/module.h>
23 #include <linux/of.h>
24 #include <linux/of_device.h>
25 #include <video/of_videomode.h>
26 #include <video/of_display_timing.h>
27 #include <linux/regulator/consumer.h>
28 #include <video/videomode.h>
29 
30 #include <video/atmel_lcdc.h>
31 
32 struct atmel_lcdfb_config {
33 	bool have_alt_pixclock;
34 	bool have_hozval;
35 	bool have_intensity_bit;
36 };
37 
38  /* LCD Controller info data structure, stored in device platform_data */
39 struct atmel_lcdfb_info {
40 	spinlock_t		lock;
41 	struct fb_info		*info;
42 	void __iomem		*mmio;
43 	int			irq_base;
44 	struct work_struct	task;
45 
46 	unsigned int		smem_len;
47 	struct platform_device	*pdev;
48 	struct clk		*bus_clk;
49 	struct clk		*lcdc_clk;
50 
51 	struct backlight_device	*backlight;
52 	u8			bl_power;
53 	u8			saved_lcdcon;
54 
55 	u32			pseudo_palette[16];
56 	bool			have_intensity_bit;
57 
58 	struct atmel_lcdfb_pdata pdata;
59 
60 	struct atmel_lcdfb_config *config;
61 	struct regulator	*reg_lcd;
62 };
63 
64 struct atmel_lcdfb_power_ctrl_gpio {
65 	struct gpio_desc *gpiod;
66 
67 	struct list_head list;
68 };
69 
70 #define lcdc_readl(sinfo, reg)		__raw_readl((sinfo)->mmio+(reg))
71 #define lcdc_writel(sinfo, reg, val)	__raw_writel((val), (sinfo)->mmio+(reg))
72 
73 /* configurable parameters */
74 #define ATMEL_LCDC_CVAL_DEFAULT		0xc8
75 #define ATMEL_LCDC_DMA_BURST_LEN	8	/* words */
76 #define ATMEL_LCDC_FIFO_SIZE		512	/* words */
77 
78 static struct atmel_lcdfb_config at91sam9261_config = {
79 	.have_hozval		= true,
80 	.have_intensity_bit	= true,
81 };
82 
83 static struct atmel_lcdfb_config at91sam9263_config = {
84 	.have_intensity_bit	= true,
85 };
86 
87 static struct atmel_lcdfb_config at91sam9g10_config = {
88 	.have_hozval		= true,
89 };
90 
91 static struct atmel_lcdfb_config at91sam9g45_config = {
92 	.have_alt_pixclock	= true,
93 };
94 
95 static struct atmel_lcdfb_config at91sam9g45es_config = {
96 };
97 
98 static struct atmel_lcdfb_config at91sam9rl_config = {
99 	.have_intensity_bit	= true,
100 };
101 
102 static u32 contrast_ctr = ATMEL_LCDC_PS_DIV8
103 		| ATMEL_LCDC_POL_POSITIVE
104 		| ATMEL_LCDC_ENA_PWMENABLE;
105 
106 #ifdef CONFIG_BACKLIGHT_ATMEL_LCDC
107 
108 /* some bl->props field just changed */
109 static int atmel_bl_update_status(struct backlight_device *bl)
110 {
111 	struct atmel_lcdfb_info *sinfo = bl_get_data(bl);
112 	int			power = sinfo->bl_power;
113 	int			brightness = bl->props.brightness;
114 
115 	/* REVISIT there may be a meaningful difference between
116 	 * fb_blank and power ... there seem to be some cases
117 	 * this doesn't handle correctly.
118 	 */
119 	if (bl->props.fb_blank != sinfo->bl_power)
120 		power = bl->props.fb_blank;
121 	else if (bl->props.power != sinfo->bl_power)
122 		power = bl->props.power;
123 
124 	if (brightness < 0 && power == FB_BLANK_UNBLANK)
125 		brightness = lcdc_readl(sinfo, ATMEL_LCDC_CONTRAST_VAL);
126 	else if (power != FB_BLANK_UNBLANK)
127 		brightness = 0;
128 
129 	lcdc_writel(sinfo, ATMEL_LCDC_CONTRAST_VAL, brightness);
130 	if (contrast_ctr & ATMEL_LCDC_POL_POSITIVE)
131 		lcdc_writel(sinfo, ATMEL_LCDC_CONTRAST_CTR,
132 			brightness ? contrast_ctr : 0);
133 	else
134 		lcdc_writel(sinfo, ATMEL_LCDC_CONTRAST_CTR, contrast_ctr);
135 
136 	bl->props.fb_blank = bl->props.power = sinfo->bl_power = power;
137 
138 	return 0;
139 }
140 
141 static int atmel_bl_get_brightness(struct backlight_device *bl)
142 {
143 	struct atmel_lcdfb_info *sinfo = bl_get_data(bl);
144 
145 	return lcdc_readl(sinfo, ATMEL_LCDC_CONTRAST_VAL);
146 }
147 
148 static const struct backlight_ops atmel_lcdc_bl_ops = {
149 	.update_status = atmel_bl_update_status,
150 	.get_brightness = atmel_bl_get_brightness,
151 };
152 
153 static void init_backlight(struct atmel_lcdfb_info *sinfo)
154 {
155 	struct backlight_properties props;
156 	struct backlight_device	*bl;
157 
158 	sinfo->bl_power = FB_BLANK_UNBLANK;
159 
160 	if (sinfo->backlight)
161 		return;
162 
163 	memset(&props, 0, sizeof(struct backlight_properties));
164 	props.type = BACKLIGHT_RAW;
165 	props.max_brightness = 0xff;
166 	bl = backlight_device_register("backlight", &sinfo->pdev->dev, sinfo,
167 				       &atmel_lcdc_bl_ops, &props);
168 	if (IS_ERR(bl)) {
169 		dev_err(&sinfo->pdev->dev, "error %ld on backlight register\n",
170 				PTR_ERR(bl));
171 		return;
172 	}
173 	sinfo->backlight = bl;
174 
175 	bl->props.power = FB_BLANK_UNBLANK;
176 	bl->props.fb_blank = FB_BLANK_UNBLANK;
177 	bl->props.brightness = atmel_bl_get_brightness(bl);
178 }
179 
180 static void exit_backlight(struct atmel_lcdfb_info *sinfo)
181 {
182 	if (!sinfo->backlight)
183 		return;
184 
185 	if (sinfo->backlight->ops) {
186 		sinfo->backlight->props.power = FB_BLANK_POWERDOWN;
187 		sinfo->backlight->ops->update_status(sinfo->backlight);
188 	}
189 	backlight_device_unregister(sinfo->backlight);
190 }
191 
192 #else
193 
194 static void init_backlight(struct atmel_lcdfb_info *sinfo)
195 {
196 	dev_warn(&sinfo->pdev->dev, "backlight control is not available\n");
197 }
198 
199 static void exit_backlight(struct atmel_lcdfb_info *sinfo)
200 {
201 }
202 
203 #endif
204 
205 static void init_contrast(struct atmel_lcdfb_info *sinfo)
206 {
207 	struct atmel_lcdfb_pdata *pdata = &sinfo->pdata;
208 
209 	/* contrast pwm can be 'inverted' */
210 	if (pdata->lcdcon_pol_negative)
211 		contrast_ctr &= ~(ATMEL_LCDC_POL_POSITIVE);
212 
213 	/* have some default contrast/backlight settings */
214 	lcdc_writel(sinfo, ATMEL_LCDC_CONTRAST_CTR, contrast_ctr);
215 	lcdc_writel(sinfo, ATMEL_LCDC_CONTRAST_VAL, ATMEL_LCDC_CVAL_DEFAULT);
216 
217 	if (pdata->lcdcon_is_backlight)
218 		init_backlight(sinfo);
219 }
220 
221 static inline void atmel_lcdfb_power_control(struct atmel_lcdfb_info *sinfo, int on)
222 {
223 	int ret;
224 	struct atmel_lcdfb_pdata *pdata = &sinfo->pdata;
225 
226 	if (pdata->atmel_lcdfb_power_control)
227 		pdata->atmel_lcdfb_power_control(pdata, on);
228 	else if (sinfo->reg_lcd) {
229 		if (on) {
230 			ret = regulator_enable(sinfo->reg_lcd);
231 			if (ret)
232 				dev_err(&sinfo->pdev->dev,
233 					"lcd regulator enable failed:	%d\n", ret);
234 		} else {
235 			ret = regulator_disable(sinfo->reg_lcd);
236 			if (ret)
237 				dev_err(&sinfo->pdev->dev,
238 					"lcd regulator disable failed: %d\n", ret);
239 		}
240 	}
241 }
242 
243 static const struct fb_fix_screeninfo atmel_lcdfb_fix __initconst = {
244 	.type		= FB_TYPE_PACKED_PIXELS,
245 	.visual		= FB_VISUAL_TRUECOLOR,
246 	.xpanstep	= 0,
247 	.ypanstep	= 1,
248 	.ywrapstep	= 0,
249 	.accel		= FB_ACCEL_NONE,
250 };
251 
252 static unsigned long compute_hozval(struct atmel_lcdfb_info *sinfo,
253 							unsigned long xres)
254 {
255 	unsigned long lcdcon2;
256 	unsigned long value;
257 
258 	if (!sinfo->config->have_hozval)
259 		return xres;
260 
261 	lcdcon2 = lcdc_readl(sinfo, ATMEL_LCDC_LCDCON2);
262 	value = xres;
263 	if ((lcdcon2 & ATMEL_LCDC_DISTYPE) != ATMEL_LCDC_DISTYPE_TFT) {
264 		/* STN display */
265 		if ((lcdcon2 & ATMEL_LCDC_DISTYPE) == ATMEL_LCDC_DISTYPE_STNCOLOR) {
266 			value *= 3;
267 		}
268 		if ( (lcdcon2 & ATMEL_LCDC_IFWIDTH) == ATMEL_LCDC_IFWIDTH_4
269 		   || ( (lcdcon2 & ATMEL_LCDC_IFWIDTH) == ATMEL_LCDC_IFWIDTH_8
270 		      && (lcdcon2 & ATMEL_LCDC_SCANMOD) == ATMEL_LCDC_SCANMOD_DUAL ))
271 			value = DIV_ROUND_UP(value, 4);
272 		else
273 			value = DIV_ROUND_UP(value, 8);
274 	}
275 
276 	return value;
277 }
278 
279 static void atmel_lcdfb_stop_nowait(struct atmel_lcdfb_info *sinfo)
280 {
281 	struct atmel_lcdfb_pdata *pdata = &sinfo->pdata;
282 
283 	/* Turn off the LCD controller and the DMA controller */
284 	lcdc_writel(sinfo, ATMEL_LCDC_PWRCON,
285 			pdata->guard_time << ATMEL_LCDC_GUARDT_OFFSET);
286 
287 	/* Wait for the LCDC core to become idle */
288 	while (lcdc_readl(sinfo, ATMEL_LCDC_PWRCON) & ATMEL_LCDC_BUSY)
289 		msleep(10);
290 
291 	lcdc_writel(sinfo, ATMEL_LCDC_DMACON, 0);
292 }
293 
294 static void atmel_lcdfb_stop(struct atmel_lcdfb_info *sinfo)
295 {
296 	atmel_lcdfb_stop_nowait(sinfo);
297 
298 	/* Wait for DMA engine to become idle... */
299 	while (lcdc_readl(sinfo, ATMEL_LCDC_DMACON) & ATMEL_LCDC_DMABUSY)
300 		msleep(10);
301 }
302 
303 static void atmel_lcdfb_start(struct atmel_lcdfb_info *sinfo)
304 {
305 	struct atmel_lcdfb_pdata *pdata = &sinfo->pdata;
306 
307 	lcdc_writel(sinfo, ATMEL_LCDC_DMACON, pdata->default_dmacon);
308 	lcdc_writel(sinfo, ATMEL_LCDC_PWRCON,
309 		(pdata->guard_time << ATMEL_LCDC_GUARDT_OFFSET)
310 		| ATMEL_LCDC_PWR);
311 }
312 
313 static void atmel_lcdfb_update_dma(struct fb_info *info,
314 			       struct fb_var_screeninfo *var)
315 {
316 	struct atmel_lcdfb_info *sinfo = info->par;
317 	struct fb_fix_screeninfo *fix = &info->fix;
318 	unsigned long dma_addr;
319 
320 	dma_addr = (fix->smem_start + var->yoffset * fix->line_length
321 		    + var->xoffset * info->var.bits_per_pixel / 8);
322 
323 	dma_addr &= ~3UL;
324 
325 	/* Set framebuffer DMA base address and pixel offset */
326 	lcdc_writel(sinfo, ATMEL_LCDC_DMABADDR1, dma_addr);
327 }
328 
329 static inline void atmel_lcdfb_free_video_memory(struct atmel_lcdfb_info *sinfo)
330 {
331 	struct fb_info *info = sinfo->info;
332 
333 	dma_free_wc(info->device, info->fix.smem_len, info->screen_base,
334 		    info->fix.smem_start);
335 }
336 
337 /**
338  *	atmel_lcdfb_alloc_video_memory - Allocate framebuffer memory
339  *	@sinfo: the frame buffer to allocate memory for
340  *
341  * 	This function is called only from the atmel_lcdfb_probe()
342  * 	so no locking by fb_info->mm_lock around smem_len setting is needed.
343  */
344 static int atmel_lcdfb_alloc_video_memory(struct atmel_lcdfb_info *sinfo)
345 {
346 	struct fb_info *info = sinfo->info;
347 	struct fb_var_screeninfo *var = &info->var;
348 	unsigned int smem_len;
349 
350 	smem_len = (var->xres_virtual * var->yres_virtual
351 		    * ((var->bits_per_pixel + 7) / 8));
352 	info->fix.smem_len = max(smem_len, sinfo->smem_len);
353 
354 	info->screen_base = dma_alloc_wc(info->device, info->fix.smem_len,
355 					 (dma_addr_t *)&info->fix.smem_start,
356 					 GFP_KERNEL);
357 
358 	if (!info->screen_base) {
359 		return -ENOMEM;
360 	}
361 
362 	memset(info->screen_base, 0, info->fix.smem_len);
363 
364 	return 0;
365 }
366 
367 static const struct fb_videomode *atmel_lcdfb_choose_mode(struct fb_var_screeninfo *var,
368 						     struct fb_info *info)
369 {
370 	struct fb_videomode varfbmode;
371 	const struct fb_videomode *fbmode = NULL;
372 
373 	fb_var_to_videomode(&varfbmode, var);
374 	fbmode = fb_find_nearest_mode(&varfbmode, &info->modelist);
375 	if (fbmode)
376 		fb_videomode_to_var(var, fbmode);
377 	return fbmode;
378 }
379 
380 
381 /**
382  *      atmel_lcdfb_check_var - Validates a var passed in.
383  *      @var: frame buffer variable screen structure
384  *      @info: frame buffer structure that represents a single frame buffer
385  *
386  *	Checks to see if the hardware supports the state requested by
387  *	var passed in. This function does not alter the hardware
388  *	state!!!  This means the data stored in struct fb_info and
389  *	struct atmel_lcdfb_info do not change. This includes the var
390  *	inside of struct fb_info.  Do NOT change these. This function
391  *	can be called on its own if we intent to only test a mode and
392  *	not actually set it. The stuff in modedb.c is a example of
393  *	this. If the var passed in is slightly off by what the
394  *	hardware can support then we alter the var PASSED in to what
395  *	we can do. If the hardware doesn't support mode change a
396  *	-EINVAL will be returned by the upper layers. You don't need
397  *	to implement this function then. If you hardware doesn't
398  *	support changing the resolution then this function is not
399  *	needed. In this case the driver would just provide a var that
400  *	represents the static state the screen is in.
401  *
402  *	Returns negative errno on error, or zero on success.
403  */
404 static int atmel_lcdfb_check_var(struct fb_var_screeninfo *var,
405 			     struct fb_info *info)
406 {
407 	struct device *dev = info->device;
408 	struct atmel_lcdfb_info *sinfo = info->par;
409 	struct atmel_lcdfb_pdata *pdata = &sinfo->pdata;
410 	unsigned long clk_value_khz;
411 
412 	clk_value_khz = clk_get_rate(sinfo->lcdc_clk) / 1000;
413 
414 	dev_dbg(dev, "%s:\n", __func__);
415 
416 	if (!(var->pixclock && var->bits_per_pixel)) {
417 		/* choose a suitable mode if possible */
418 		if (!atmel_lcdfb_choose_mode(var, info)) {
419 			dev_err(dev, "needed value not specified\n");
420 			return -EINVAL;
421 		}
422 	}
423 
424 	dev_dbg(dev, "  resolution: %ux%u\n", var->xres, var->yres);
425 	dev_dbg(dev, "  pixclk:     %lu KHz\n", PICOS2KHZ(var->pixclock));
426 	dev_dbg(dev, "  bpp:        %u\n", var->bits_per_pixel);
427 	dev_dbg(dev, "  clk:        %lu KHz\n", clk_value_khz);
428 
429 	if (PICOS2KHZ(var->pixclock) > clk_value_khz) {
430 		dev_err(dev, "%lu KHz pixel clock is too fast\n", PICOS2KHZ(var->pixclock));
431 		return -EINVAL;
432 	}
433 
434 	/* Do not allow to have real resoulution larger than virtual */
435 	if (var->xres > var->xres_virtual)
436 		var->xres_virtual = var->xres;
437 
438 	if (var->yres > var->yres_virtual)
439 		var->yres_virtual = var->yres;
440 
441 	/* Force same alignment for each line */
442 	var->xres = (var->xres + 3) & ~3UL;
443 	var->xres_virtual = (var->xres_virtual + 3) & ~3UL;
444 
445 	var->red.msb_right = var->green.msb_right = var->blue.msb_right = 0;
446 	var->transp.msb_right = 0;
447 	var->transp.offset = var->transp.length = 0;
448 	var->xoffset = var->yoffset = 0;
449 
450 	if (info->fix.smem_len) {
451 		unsigned int smem_len = (var->xres_virtual * var->yres_virtual
452 					 * ((var->bits_per_pixel + 7) / 8));
453 		if (smem_len > info->fix.smem_len) {
454 			dev_err(dev, "Frame buffer is too small (%u) for screen size (need at least %u)\n",
455 				info->fix.smem_len, smem_len);
456 			return -EINVAL;
457 		}
458 	}
459 
460 	/* Saturate vertical and horizontal timings at maximum values */
461 	var->vsync_len = min_t(u32, var->vsync_len,
462 			(ATMEL_LCDC_VPW >> ATMEL_LCDC_VPW_OFFSET) + 1);
463 	var->upper_margin = min_t(u32, var->upper_margin,
464 			ATMEL_LCDC_VBP >> ATMEL_LCDC_VBP_OFFSET);
465 	var->lower_margin = min_t(u32, var->lower_margin,
466 			ATMEL_LCDC_VFP);
467 	var->right_margin = min_t(u32, var->right_margin,
468 			(ATMEL_LCDC_HFP >> ATMEL_LCDC_HFP_OFFSET) + 1);
469 	var->hsync_len = min_t(u32, var->hsync_len,
470 			(ATMEL_LCDC_HPW >> ATMEL_LCDC_HPW_OFFSET) + 1);
471 	var->left_margin = min_t(u32, var->left_margin,
472 			ATMEL_LCDC_HBP + 1);
473 
474 	/* Some parameters can't be zero */
475 	var->vsync_len = max_t(u32, var->vsync_len, 1);
476 	var->right_margin = max_t(u32, var->right_margin, 1);
477 	var->hsync_len = max_t(u32, var->hsync_len, 1);
478 	var->left_margin = max_t(u32, var->left_margin, 1);
479 
480 	switch (var->bits_per_pixel) {
481 	case 1:
482 	case 2:
483 	case 4:
484 	case 8:
485 		var->red.offset = var->green.offset = var->blue.offset = 0;
486 		var->red.length = var->green.length = var->blue.length
487 			= var->bits_per_pixel;
488 		break;
489 	case 16:
490 		/* Older SOCs use IBGR:555 rather than BGR:565. */
491 		if (sinfo->config->have_intensity_bit)
492 			var->green.length = 5;
493 		else
494 			var->green.length = 6;
495 
496 		if (pdata->lcd_wiring_mode == ATMEL_LCDC_WIRING_RGB) {
497 			/* RGB:5X5 mode */
498 			var->red.offset = var->green.length + 5;
499 			var->blue.offset = 0;
500 		} else {
501 			/* BGR:5X5 mode */
502 			var->red.offset = 0;
503 			var->blue.offset = var->green.length + 5;
504 		}
505 		var->green.offset = 5;
506 		var->red.length = var->blue.length = 5;
507 		break;
508 	case 32:
509 		var->transp.offset = 24;
510 		var->transp.length = 8;
511 		fallthrough;
512 	case 24:
513 		if (pdata->lcd_wiring_mode == ATMEL_LCDC_WIRING_RGB) {
514 			/* RGB:888 mode */
515 			var->red.offset = 16;
516 			var->blue.offset = 0;
517 		} else {
518 			/* BGR:888 mode */
519 			var->red.offset = 0;
520 			var->blue.offset = 16;
521 		}
522 		var->green.offset = 8;
523 		var->red.length = var->green.length = var->blue.length = 8;
524 		break;
525 	default:
526 		dev_err(dev, "color depth %d not supported\n",
527 					var->bits_per_pixel);
528 		return -EINVAL;
529 	}
530 
531 	return 0;
532 }
533 
534 /*
535  * LCD reset sequence
536  */
537 static void atmel_lcdfb_reset(struct atmel_lcdfb_info *sinfo)
538 {
539 	might_sleep();
540 
541 	atmel_lcdfb_stop(sinfo);
542 	atmel_lcdfb_start(sinfo);
543 }
544 
545 /**
546  *      atmel_lcdfb_set_par - Alters the hardware state.
547  *      @info: frame buffer structure that represents a single frame buffer
548  *
549  *	Using the fb_var_screeninfo in fb_info we set the resolution
550  *	of the this particular framebuffer. This function alters the
551  *	par AND the fb_fix_screeninfo stored in fb_info. It doesn't
552  *	not alter var in fb_info since we are using that data. This
553  *	means we depend on the data in var inside fb_info to be
554  *	supported by the hardware.  atmel_lcdfb_check_var is always called
555  *	before atmel_lcdfb_set_par to ensure this.  Again if you can't
556  *	change the resolution you don't need this function.
557  *
558  */
559 static int atmel_lcdfb_set_par(struct fb_info *info)
560 {
561 	struct atmel_lcdfb_info *sinfo = info->par;
562 	struct atmel_lcdfb_pdata *pdata = &sinfo->pdata;
563 	unsigned long hozval_linesz;
564 	unsigned long value;
565 	unsigned long clk_value_khz;
566 	unsigned long bits_per_line;
567 	unsigned long pix_factor = 2;
568 
569 	might_sleep();
570 
571 	dev_dbg(info->device, "%s:\n", __func__);
572 	dev_dbg(info->device, "  * resolution: %ux%u (%ux%u virtual)\n",
573 		 info->var.xres, info->var.yres,
574 		 info->var.xres_virtual, info->var.yres_virtual);
575 
576 	atmel_lcdfb_stop_nowait(sinfo);
577 
578 	if (info->var.bits_per_pixel == 1)
579 		info->fix.visual = FB_VISUAL_MONO01;
580 	else if (info->var.bits_per_pixel <= 8)
581 		info->fix.visual = FB_VISUAL_PSEUDOCOLOR;
582 	else
583 		info->fix.visual = FB_VISUAL_TRUECOLOR;
584 
585 	bits_per_line = info->var.xres_virtual * info->var.bits_per_pixel;
586 	info->fix.line_length = DIV_ROUND_UP(bits_per_line, 8);
587 
588 	/* Re-initialize the DMA engine... */
589 	dev_dbg(info->device, "  * update DMA engine\n");
590 	atmel_lcdfb_update_dma(info, &info->var);
591 
592 	/* ...set frame size and burst length = 8 words (?) */
593 	value = (info->var.yres * info->var.xres * info->var.bits_per_pixel) / 32;
594 	value |= ((ATMEL_LCDC_DMA_BURST_LEN - 1) << ATMEL_LCDC_BLENGTH_OFFSET);
595 	lcdc_writel(sinfo, ATMEL_LCDC_DMAFRMCFG, value);
596 
597 	/* Now, the LCDC core... */
598 
599 	/* Set pixel clock */
600 	if (sinfo->config->have_alt_pixclock)
601 		pix_factor = 1;
602 
603 	clk_value_khz = clk_get_rate(sinfo->lcdc_clk) / 1000;
604 
605 	value = DIV_ROUND_UP(clk_value_khz, PICOS2KHZ(info->var.pixclock));
606 
607 	if (value < pix_factor) {
608 		dev_notice(info->device, "Bypassing pixel clock divider\n");
609 		lcdc_writel(sinfo, ATMEL_LCDC_LCDCON1, ATMEL_LCDC_BYPASS);
610 	} else {
611 		value = (value / pix_factor) - 1;
612 		dev_dbg(info->device, "  * programming CLKVAL = 0x%08lx\n",
613 				value);
614 		lcdc_writel(sinfo, ATMEL_LCDC_LCDCON1,
615 				value << ATMEL_LCDC_CLKVAL_OFFSET);
616 		info->var.pixclock =
617 			KHZ2PICOS(clk_value_khz / (pix_factor * (value + 1)));
618 		dev_dbg(info->device, "  updated pixclk:     %lu KHz\n",
619 					PICOS2KHZ(info->var.pixclock));
620 	}
621 
622 
623 	/* Initialize control register 2 */
624 	value = pdata->default_lcdcon2;
625 
626 	if (!(info->var.sync & FB_SYNC_HOR_HIGH_ACT))
627 		value |= ATMEL_LCDC_INVLINE_INVERTED;
628 	if (!(info->var.sync & FB_SYNC_VERT_HIGH_ACT))
629 		value |= ATMEL_LCDC_INVFRAME_INVERTED;
630 
631 	switch (info->var.bits_per_pixel) {
632 		case 1:	value |= ATMEL_LCDC_PIXELSIZE_1; break;
633 		case 2: value |= ATMEL_LCDC_PIXELSIZE_2; break;
634 		case 4: value |= ATMEL_LCDC_PIXELSIZE_4; break;
635 		case 8: value |= ATMEL_LCDC_PIXELSIZE_8; break;
636 		case 15: fallthrough;
637 		case 16: value |= ATMEL_LCDC_PIXELSIZE_16; break;
638 		case 24: value |= ATMEL_LCDC_PIXELSIZE_24; break;
639 		case 32: value |= ATMEL_LCDC_PIXELSIZE_32; break;
640 		default: BUG(); break;
641 	}
642 	dev_dbg(info->device, "  * LCDCON2 = %08lx\n", value);
643 	lcdc_writel(sinfo, ATMEL_LCDC_LCDCON2, value);
644 
645 	/* Vertical timing */
646 	value = (info->var.vsync_len - 1) << ATMEL_LCDC_VPW_OFFSET;
647 	value |= info->var.upper_margin << ATMEL_LCDC_VBP_OFFSET;
648 	value |= info->var.lower_margin;
649 	dev_dbg(info->device, "  * LCDTIM1 = %08lx\n", value);
650 	lcdc_writel(sinfo, ATMEL_LCDC_TIM1, value);
651 
652 	/* Horizontal timing */
653 	value = (info->var.right_margin - 1) << ATMEL_LCDC_HFP_OFFSET;
654 	value |= (info->var.hsync_len - 1) << ATMEL_LCDC_HPW_OFFSET;
655 	value |= (info->var.left_margin - 1);
656 	dev_dbg(info->device, "  * LCDTIM2 = %08lx\n", value);
657 	lcdc_writel(sinfo, ATMEL_LCDC_TIM2, value);
658 
659 	/* Horizontal value (aka line size) */
660 	hozval_linesz = compute_hozval(sinfo, info->var.xres);
661 
662 	/* Display size */
663 	value = (hozval_linesz - 1) << ATMEL_LCDC_HOZVAL_OFFSET;
664 	value |= info->var.yres - 1;
665 	dev_dbg(info->device, "  * LCDFRMCFG = %08lx\n", value);
666 	lcdc_writel(sinfo, ATMEL_LCDC_LCDFRMCFG, value);
667 
668 	/* FIFO Threshold: Use formula from data sheet */
669 	value = ATMEL_LCDC_FIFO_SIZE - (2 * ATMEL_LCDC_DMA_BURST_LEN + 3);
670 	lcdc_writel(sinfo, ATMEL_LCDC_FIFO, value);
671 
672 	/* Toggle LCD_MODE every frame */
673 	lcdc_writel(sinfo, ATMEL_LCDC_MVAL, 0);
674 
675 	/* Disable all interrupts */
676 	lcdc_writel(sinfo, ATMEL_LCDC_IDR, ~0U);
677 	/* Enable FIFO & DMA errors */
678 	lcdc_writel(sinfo, ATMEL_LCDC_IER, ATMEL_LCDC_UFLWI | ATMEL_LCDC_OWRI | ATMEL_LCDC_MERI);
679 
680 	/* ...wait for DMA engine to become idle... */
681 	while (lcdc_readl(sinfo, ATMEL_LCDC_DMACON) & ATMEL_LCDC_DMABUSY)
682 		msleep(10);
683 
684 	atmel_lcdfb_start(sinfo);
685 
686 	dev_dbg(info->device, "  * DONE\n");
687 
688 	return 0;
689 }
690 
691 static inline unsigned int chan_to_field(unsigned int chan, const struct fb_bitfield *bf)
692 {
693 	chan &= 0xffff;
694 	chan >>= 16 - bf->length;
695 	return chan << bf->offset;
696 }
697 
698 /**
699  *  	atmel_lcdfb_setcolreg - Optional function. Sets a color register.
700  *      @regno: Which register in the CLUT we are programming
701  *      @red: The red value which can be up to 16 bits wide
702  *	@green: The green value which can be up to 16 bits wide
703  *	@blue:  The blue value which can be up to 16 bits wide.
704  *	@transp: If supported the alpha value which can be up to 16 bits wide.
705  *      @info: frame buffer info structure
706  *
707  *  	Set a single color register. The values supplied have a 16 bit
708  *  	magnitude which needs to be scaled in this function for the hardware.
709  *	Things to take into consideration are how many color registers, if
710  *	any, are supported with the current color visual. With truecolor mode
711  *	no color palettes are supported. Here a pseudo palette is created
712  *	which we store the value in pseudo_palette in struct fb_info. For
713  *	pseudocolor mode we have a limited color palette. To deal with this
714  *	we can program what color is displayed for a particular pixel value.
715  *	DirectColor is similar in that we can program each color field. If
716  *	we have a static colormap we don't need to implement this function.
717  *
718  *	Returns negative errno on error, or zero on success. In an
719  *	ideal world, this would have been the case, but as it turns
720  *	out, the other drivers return 1 on failure, so that's what
721  *	we're going to do.
722  */
723 static int atmel_lcdfb_setcolreg(unsigned int regno, unsigned int red,
724 			     unsigned int green, unsigned int blue,
725 			     unsigned int transp, struct fb_info *info)
726 {
727 	struct atmel_lcdfb_info *sinfo = info->par;
728 	struct atmel_lcdfb_pdata *pdata = &sinfo->pdata;
729 	unsigned int val;
730 	u32 *pal;
731 	int ret = 1;
732 
733 	if (info->var.grayscale)
734 		red = green = blue = (19595 * red + 38470 * green
735 				      + 7471 * blue) >> 16;
736 
737 	switch (info->fix.visual) {
738 	case FB_VISUAL_TRUECOLOR:
739 		if (regno < 16) {
740 			pal = info->pseudo_palette;
741 
742 			val  = chan_to_field(red, &info->var.red);
743 			val |= chan_to_field(green, &info->var.green);
744 			val |= chan_to_field(blue, &info->var.blue);
745 
746 			pal[regno] = val;
747 			ret = 0;
748 		}
749 		break;
750 
751 	case FB_VISUAL_PSEUDOCOLOR:
752 		if (regno < 256) {
753 			if (sinfo->config->have_intensity_bit) {
754 				/* old style I+BGR:555 */
755 				val  = ((red   >> 11) & 0x001f);
756 				val |= ((green >>  6) & 0x03e0);
757 				val |= ((blue  >>  1) & 0x7c00);
758 
759 				/*
760 				 * TODO: intensity bit. Maybe something like
761 				 *   ~(red[10] ^ green[10] ^ blue[10]) & 1
762 				 */
763 			} else {
764 				/* new style BGR:565 / RGB:565 */
765 				if (pdata->lcd_wiring_mode == ATMEL_LCDC_WIRING_RGB) {
766 					val  = ((blue >> 11) & 0x001f);
767 					val |= ((red  >>  0) & 0xf800);
768 				} else {
769 					val  = ((red  >> 11) & 0x001f);
770 					val |= ((blue >>  0) & 0xf800);
771 				}
772 
773 				val |= ((green >>  5) & 0x07e0);
774 			}
775 
776 			lcdc_writel(sinfo, ATMEL_LCDC_LUT(regno), val);
777 			ret = 0;
778 		}
779 		break;
780 
781 	case FB_VISUAL_MONO01:
782 		if (regno < 2) {
783 			val = (regno == 0) ? 0x00 : 0x1F;
784 			lcdc_writel(sinfo, ATMEL_LCDC_LUT(regno), val);
785 			ret = 0;
786 		}
787 		break;
788 
789 	}
790 
791 	return ret;
792 }
793 
794 static int atmel_lcdfb_pan_display(struct fb_var_screeninfo *var,
795 			       struct fb_info *info)
796 {
797 	dev_dbg(info->device, "%s\n", __func__);
798 
799 	atmel_lcdfb_update_dma(info, var);
800 
801 	return 0;
802 }
803 
804 static int atmel_lcdfb_blank(int blank_mode, struct fb_info *info)
805 {
806 	struct atmel_lcdfb_info *sinfo = info->par;
807 
808 	switch (blank_mode) {
809 	case FB_BLANK_UNBLANK:
810 	case FB_BLANK_NORMAL:
811 		atmel_lcdfb_start(sinfo);
812 		break;
813 	case FB_BLANK_VSYNC_SUSPEND:
814 	case FB_BLANK_HSYNC_SUSPEND:
815 		break;
816 	case FB_BLANK_POWERDOWN:
817 		atmel_lcdfb_stop(sinfo);
818 		break;
819 	default:
820 		return -EINVAL;
821 	}
822 
823 	/* let fbcon do a soft blank for us */
824 	return ((blank_mode == FB_BLANK_NORMAL) ? 1 : 0);
825 }
826 
827 static const struct fb_ops atmel_lcdfb_ops = {
828 	.owner		= THIS_MODULE,
829 	.fb_check_var	= atmel_lcdfb_check_var,
830 	.fb_set_par	= atmel_lcdfb_set_par,
831 	.fb_setcolreg	= atmel_lcdfb_setcolreg,
832 	.fb_blank	= atmel_lcdfb_blank,
833 	.fb_pan_display	= atmel_lcdfb_pan_display,
834 	.fb_fillrect	= cfb_fillrect,
835 	.fb_copyarea	= cfb_copyarea,
836 	.fb_imageblit	= cfb_imageblit,
837 };
838 
839 static irqreturn_t atmel_lcdfb_interrupt(int irq, void *dev_id)
840 {
841 	struct fb_info *info = dev_id;
842 	struct atmel_lcdfb_info *sinfo = info->par;
843 	u32 status;
844 
845 	status = lcdc_readl(sinfo, ATMEL_LCDC_ISR);
846 	if (status & ATMEL_LCDC_UFLWI) {
847 		dev_warn(info->device, "FIFO underflow %#x\n", status);
848 		/* reset DMA and FIFO to avoid screen shifting */
849 		schedule_work(&sinfo->task);
850 	}
851 	lcdc_writel(sinfo, ATMEL_LCDC_ICR, status);
852 	return IRQ_HANDLED;
853 }
854 
855 /*
856  * LCD controller task (to reset the LCD)
857  */
858 static void atmel_lcdfb_task(struct work_struct *work)
859 {
860 	struct atmel_lcdfb_info *sinfo =
861 		container_of(work, struct atmel_lcdfb_info, task);
862 
863 	atmel_lcdfb_reset(sinfo);
864 }
865 
866 static int __init atmel_lcdfb_init_fbinfo(struct atmel_lcdfb_info *sinfo)
867 {
868 	struct fb_info *info = sinfo->info;
869 	int ret = 0;
870 
871 	info->var.activate |= FB_ACTIVATE_FORCE | FB_ACTIVATE_NOW;
872 
873 	dev_info(info->device,
874 	       "%luKiB frame buffer at %08lx (mapped at %p)\n",
875 	       (unsigned long)info->fix.smem_len / 1024,
876 	       (unsigned long)info->fix.smem_start,
877 	       info->screen_base);
878 
879 	/* Allocate colormap */
880 	ret = fb_alloc_cmap(&info->cmap, 256, 0);
881 	if (ret < 0)
882 		dev_err(info->device, "Alloc color map failed\n");
883 
884 	return ret;
885 }
886 
887 static void atmel_lcdfb_start_clock(struct atmel_lcdfb_info *sinfo)
888 {
889 	clk_prepare_enable(sinfo->bus_clk);
890 	clk_prepare_enable(sinfo->lcdc_clk);
891 }
892 
893 static void atmel_lcdfb_stop_clock(struct atmel_lcdfb_info *sinfo)
894 {
895 	clk_disable_unprepare(sinfo->bus_clk);
896 	clk_disable_unprepare(sinfo->lcdc_clk);
897 }
898 
899 static const struct of_device_id atmel_lcdfb_dt_ids[] = {
900 	{ .compatible = "atmel,at91sam9261-lcdc" , .data = &at91sam9261_config, },
901 	{ .compatible = "atmel,at91sam9263-lcdc" , .data = &at91sam9263_config, },
902 	{ .compatible = "atmel,at91sam9g10-lcdc" , .data = &at91sam9g10_config, },
903 	{ .compatible = "atmel,at91sam9g45-lcdc" , .data = &at91sam9g45_config, },
904 	{ .compatible = "atmel,at91sam9g45es-lcdc" , .data = &at91sam9g45es_config, },
905 	{ .compatible = "atmel,at91sam9rl-lcdc" , .data = &at91sam9rl_config, },
906 	{ /* sentinel */ }
907 };
908 
909 MODULE_DEVICE_TABLE(of, atmel_lcdfb_dt_ids);
910 
911 static const char *atmel_lcdfb_wiring_modes[] = {
912 	[ATMEL_LCDC_WIRING_BGR]	= "BRG",
913 	[ATMEL_LCDC_WIRING_RGB]	= "RGB",
914 };
915 
916 static int atmel_lcdfb_get_of_wiring_modes(struct device_node *np)
917 {
918 	const char *mode;
919 	int err, i;
920 
921 	err = of_property_read_string(np, "atmel,lcd-wiring-mode", &mode);
922 	if (err < 0)
923 		return ATMEL_LCDC_WIRING_BGR;
924 
925 	for (i = 0; i < ARRAY_SIZE(atmel_lcdfb_wiring_modes); i++)
926 		if (!strcasecmp(mode, atmel_lcdfb_wiring_modes[i]))
927 			return i;
928 
929 	return -ENODEV;
930 }
931 
932 static void atmel_lcdfb_power_control_gpio(struct atmel_lcdfb_pdata *pdata, int on)
933 {
934 	struct atmel_lcdfb_power_ctrl_gpio *og;
935 
936 	list_for_each_entry(og, &pdata->pwr_gpios, list)
937 		gpiod_set_value(og->gpiod, on);
938 }
939 
940 static int atmel_lcdfb_of_init(struct atmel_lcdfb_info *sinfo)
941 {
942 	struct fb_info *info = sinfo->info;
943 	struct atmel_lcdfb_pdata *pdata = &sinfo->pdata;
944 	struct fb_var_screeninfo *var = &info->var;
945 	struct device *dev = &sinfo->pdev->dev;
946 	struct device_node *np =dev->of_node;
947 	struct device_node *display_np;
948 	struct atmel_lcdfb_power_ctrl_gpio *og;
949 	bool is_gpio_power = false;
950 	struct fb_videomode fb_vm;
951 	struct gpio_desc *gpiod;
952 	struct videomode vm;
953 	int ret;
954 	int i;
955 
956 	sinfo->config = (struct atmel_lcdfb_config*)
957 		of_match_device(atmel_lcdfb_dt_ids, dev)->data;
958 
959 	display_np = of_parse_phandle(np, "display", 0);
960 	if (!display_np) {
961 		dev_err(dev, "failed to find display phandle\n");
962 		return -ENOENT;
963 	}
964 
965 	ret = of_property_read_u32(display_np, "bits-per-pixel", &var->bits_per_pixel);
966 	if (ret < 0) {
967 		dev_err(dev, "failed to get property bits-per-pixel\n");
968 		goto put_display_node;
969 	}
970 
971 	ret = of_property_read_u32(display_np, "atmel,guard-time", &pdata->guard_time);
972 	if (ret < 0) {
973 		dev_err(dev, "failed to get property atmel,guard-time\n");
974 		goto put_display_node;
975 	}
976 
977 	ret = of_property_read_u32(display_np, "atmel,lcdcon2", &pdata->default_lcdcon2);
978 	if (ret < 0) {
979 		dev_err(dev, "failed to get property atmel,lcdcon2\n");
980 		goto put_display_node;
981 	}
982 
983 	ret = of_property_read_u32(display_np, "atmel,dmacon", &pdata->default_dmacon);
984 	if (ret < 0) {
985 		dev_err(dev, "failed to get property bits-per-pixel\n");
986 		goto put_display_node;
987 	}
988 
989 	INIT_LIST_HEAD(&pdata->pwr_gpios);
990 	for (i = 0; i < gpiod_count(dev, "atmel,power-control"); i++) {
991 		ret = -ENOMEM;
992 		gpiod = devm_gpiod_get_index(dev, "atmel,power-control",
993 					     i, GPIOD_ASIS);
994 		if (IS_ERR(gpiod))
995 			continue;
996 
997 		og = devm_kzalloc(dev, sizeof(*og), GFP_KERNEL);
998 		if (!og)
999 			goto put_display_node;
1000 
1001 		og->gpiod = gpiod;
1002 		is_gpio_power = true;
1003 
1004 		ret = gpiod_direction_output(gpiod, gpiod_is_active_low(gpiod));
1005 		if (ret) {
1006 			dev_err(dev, "set direction output gpio atmel,power-control[%d] failed\n", i);
1007 			goto put_display_node;
1008 		}
1009 		list_add(&og->list, &pdata->pwr_gpios);
1010 	}
1011 
1012 	if (is_gpio_power)
1013 		pdata->atmel_lcdfb_power_control = atmel_lcdfb_power_control_gpio;
1014 
1015 	ret = atmel_lcdfb_get_of_wiring_modes(display_np);
1016 	if (ret < 0) {
1017 		dev_err(dev, "invalid atmel,lcd-wiring-mode\n");
1018 		goto put_display_node;
1019 	}
1020 	pdata->lcd_wiring_mode = ret;
1021 
1022 	pdata->lcdcon_is_backlight = of_property_read_bool(display_np, "atmel,lcdcon-backlight");
1023 	pdata->lcdcon_pol_negative = of_property_read_bool(display_np, "atmel,lcdcon-backlight-inverted");
1024 
1025 	ret = of_get_videomode(display_np, &vm, OF_USE_NATIVE_MODE);
1026 	if (ret) {
1027 		dev_err(dev, "failed to get videomode from DT\n");
1028 		goto put_display_node;
1029 	}
1030 
1031 	ret = fb_videomode_from_videomode(&vm, &fb_vm);
1032 	if (ret < 0)
1033 		goto put_display_node;
1034 
1035 	fb_add_videomode(&fb_vm, &info->modelist);
1036 
1037 put_display_node:
1038 	of_node_put(display_np);
1039 	return ret;
1040 }
1041 
1042 static int __init atmel_lcdfb_probe(struct platform_device *pdev)
1043 {
1044 	struct device *dev = &pdev->dev;
1045 	struct fb_info *info;
1046 	struct atmel_lcdfb_info *sinfo;
1047 	struct resource *regs = NULL;
1048 	struct resource *map = NULL;
1049 	struct fb_modelist *modelist;
1050 	int ret;
1051 
1052 	dev_dbg(dev, "%s BEGIN\n", __func__);
1053 
1054 	ret = -ENOMEM;
1055 	info = framebuffer_alloc(sizeof(struct atmel_lcdfb_info), dev);
1056 	if (!info)
1057 		goto out;
1058 
1059 	sinfo = info->par;
1060 	sinfo->pdev = pdev;
1061 	sinfo->info = info;
1062 
1063 	INIT_LIST_HEAD(&info->modelist);
1064 
1065 	if (!pdev->dev.of_node) {
1066 		dev_err(dev, "cannot get default configuration\n");
1067 		goto free_info;
1068 	}
1069 
1070 	ret = atmel_lcdfb_of_init(sinfo);
1071 	if (ret)
1072 		goto free_info;
1073 
1074 	ret = -ENODEV;
1075 	if (!sinfo->config)
1076 		goto free_info;
1077 
1078 	sinfo->reg_lcd = devm_regulator_get(&pdev->dev, "lcd");
1079 	if (IS_ERR(sinfo->reg_lcd))
1080 		sinfo->reg_lcd = NULL;
1081 
1082 	info->flags = FBINFO_DEFAULT | FBINFO_PARTIAL_PAN_OK |
1083 		      FBINFO_HWACCEL_YPAN;
1084 	info->pseudo_palette = sinfo->pseudo_palette;
1085 	info->fbops = &atmel_lcdfb_ops;
1086 
1087 	info->fix = atmel_lcdfb_fix;
1088 	strcpy(info->fix.id, sinfo->pdev->name);
1089 
1090 	/* Enable LCDC Clocks */
1091 	sinfo->bus_clk = clk_get(dev, "hclk");
1092 	if (IS_ERR(sinfo->bus_clk)) {
1093 		ret = PTR_ERR(sinfo->bus_clk);
1094 		goto free_info;
1095 	}
1096 	sinfo->lcdc_clk = clk_get(dev, "lcdc_clk");
1097 	if (IS_ERR(sinfo->lcdc_clk)) {
1098 		ret = PTR_ERR(sinfo->lcdc_clk);
1099 		goto put_bus_clk;
1100 	}
1101 	atmel_lcdfb_start_clock(sinfo);
1102 
1103 	modelist = list_first_entry(&info->modelist,
1104 			struct fb_modelist, list);
1105 	fb_videomode_to_var(&info->var, &modelist->mode);
1106 
1107 	atmel_lcdfb_check_var(&info->var, info);
1108 
1109 	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1110 	if (!regs) {
1111 		dev_err(dev, "resources unusable\n");
1112 		ret = -ENXIO;
1113 		goto stop_clk;
1114 	}
1115 
1116 	sinfo->irq_base = platform_get_irq(pdev, 0);
1117 	if (sinfo->irq_base < 0) {
1118 		ret = sinfo->irq_base;
1119 		goto stop_clk;
1120 	}
1121 
1122 	/* Initialize video memory */
1123 	map = platform_get_resource(pdev, IORESOURCE_MEM, 1);
1124 	if (map) {
1125 		/* use a pre-allocated memory buffer */
1126 		info->fix.smem_start = map->start;
1127 		info->fix.smem_len = resource_size(map);
1128 		if (!request_mem_region(info->fix.smem_start,
1129 					info->fix.smem_len, pdev->name)) {
1130 			ret = -EBUSY;
1131 			goto stop_clk;
1132 		}
1133 
1134 		info->screen_base = ioremap_wc(info->fix.smem_start,
1135 					       info->fix.smem_len);
1136 		if (!info->screen_base) {
1137 			ret = -ENOMEM;
1138 			goto release_intmem;
1139 		}
1140 
1141 		/*
1142 		 * Don't clear the framebuffer -- someone may have set
1143 		 * up a splash image.
1144 		 */
1145 	} else {
1146 		/* allocate memory buffer */
1147 		ret = atmel_lcdfb_alloc_video_memory(sinfo);
1148 		if (ret < 0) {
1149 			dev_err(dev, "cannot allocate framebuffer: %d\n", ret);
1150 			goto stop_clk;
1151 		}
1152 	}
1153 
1154 	/* LCDC registers */
1155 	info->fix.mmio_start = regs->start;
1156 	info->fix.mmio_len = resource_size(regs);
1157 
1158 	if (!request_mem_region(info->fix.mmio_start,
1159 				info->fix.mmio_len, pdev->name)) {
1160 		ret = -EBUSY;
1161 		goto free_fb;
1162 	}
1163 
1164 	sinfo->mmio = ioremap(info->fix.mmio_start, info->fix.mmio_len);
1165 	if (!sinfo->mmio) {
1166 		dev_err(dev, "cannot map LCDC registers\n");
1167 		ret = -ENOMEM;
1168 		goto release_mem;
1169 	}
1170 
1171 	/* Initialize PWM for contrast or backlight ("off") */
1172 	init_contrast(sinfo);
1173 
1174 	/* interrupt */
1175 	ret = request_irq(sinfo->irq_base, atmel_lcdfb_interrupt, 0, pdev->name, info);
1176 	if (ret) {
1177 		dev_err(dev, "request_irq failed: %d\n", ret);
1178 		goto unmap_mmio;
1179 	}
1180 
1181 	/* Some operations on the LCDC might sleep and
1182 	 * require a preemptible task context */
1183 	INIT_WORK(&sinfo->task, atmel_lcdfb_task);
1184 
1185 	ret = atmel_lcdfb_init_fbinfo(sinfo);
1186 	if (ret < 0) {
1187 		dev_err(dev, "init fbinfo failed: %d\n", ret);
1188 		goto unregister_irqs;
1189 	}
1190 
1191 	ret = atmel_lcdfb_set_par(info);
1192 	if (ret < 0) {
1193 		dev_err(dev, "set par failed: %d\n", ret);
1194 		goto unregister_irqs;
1195 	}
1196 
1197 	dev_set_drvdata(dev, info);
1198 
1199 	/*
1200 	 * Tell the world that we're ready to go
1201 	 */
1202 	ret = register_framebuffer(info);
1203 	if (ret < 0) {
1204 		dev_err(dev, "failed to register framebuffer device: %d\n", ret);
1205 		goto reset_drvdata;
1206 	}
1207 
1208 	/* Power up the LCDC screen */
1209 	atmel_lcdfb_power_control(sinfo, 1);
1210 
1211 	dev_info(dev, "fb%d: Atmel LCDC at 0x%08lx (mapped at %p), irq %d\n",
1212 		       info->node, info->fix.mmio_start, sinfo->mmio, sinfo->irq_base);
1213 
1214 	return 0;
1215 
1216 reset_drvdata:
1217 	dev_set_drvdata(dev, NULL);
1218 	fb_dealloc_cmap(&info->cmap);
1219 unregister_irqs:
1220 	cancel_work_sync(&sinfo->task);
1221 	free_irq(sinfo->irq_base, info);
1222 unmap_mmio:
1223 	exit_backlight(sinfo);
1224 	iounmap(sinfo->mmio);
1225 release_mem:
1226  	release_mem_region(info->fix.mmio_start, info->fix.mmio_len);
1227 free_fb:
1228 	if (map)
1229 		iounmap(info->screen_base);
1230 	else
1231 		atmel_lcdfb_free_video_memory(sinfo);
1232 
1233 release_intmem:
1234 	if (map)
1235 		release_mem_region(info->fix.smem_start, info->fix.smem_len);
1236 stop_clk:
1237 	atmel_lcdfb_stop_clock(sinfo);
1238 	clk_put(sinfo->lcdc_clk);
1239 put_bus_clk:
1240 	clk_put(sinfo->bus_clk);
1241 free_info:
1242 	framebuffer_release(info);
1243 out:
1244 	dev_dbg(dev, "%s FAILED\n", __func__);
1245 	return ret;
1246 }
1247 
1248 static int __exit atmel_lcdfb_remove(struct platform_device *pdev)
1249 {
1250 	struct device *dev = &pdev->dev;
1251 	struct fb_info *info = dev_get_drvdata(dev);
1252 	struct atmel_lcdfb_info *sinfo;
1253 
1254 	if (!info || !info->par)
1255 		return 0;
1256 	sinfo = info->par;
1257 
1258 	cancel_work_sync(&sinfo->task);
1259 	exit_backlight(sinfo);
1260 	atmel_lcdfb_power_control(sinfo, 0);
1261 	unregister_framebuffer(info);
1262 	atmel_lcdfb_stop_clock(sinfo);
1263 	clk_put(sinfo->lcdc_clk);
1264 	clk_put(sinfo->bus_clk);
1265 	fb_dealloc_cmap(&info->cmap);
1266 	free_irq(sinfo->irq_base, info);
1267 	iounmap(sinfo->mmio);
1268  	release_mem_region(info->fix.mmio_start, info->fix.mmio_len);
1269 	if (platform_get_resource(pdev, IORESOURCE_MEM, 1)) {
1270 		iounmap(info->screen_base);
1271 		release_mem_region(info->fix.smem_start, info->fix.smem_len);
1272 	} else {
1273 		atmel_lcdfb_free_video_memory(sinfo);
1274 	}
1275 
1276 	framebuffer_release(info);
1277 
1278 	return 0;
1279 }
1280 
1281 #ifdef CONFIG_PM
1282 
1283 static int atmel_lcdfb_suspend(struct platform_device *pdev, pm_message_t mesg)
1284 {
1285 	struct fb_info *info = platform_get_drvdata(pdev);
1286 	struct atmel_lcdfb_info *sinfo = info->par;
1287 
1288 	/*
1289 	 * We don't want to handle interrupts while the clock is
1290 	 * stopped. It may take forever.
1291 	 */
1292 	lcdc_writel(sinfo, ATMEL_LCDC_IDR, ~0U);
1293 
1294 	sinfo->saved_lcdcon = lcdc_readl(sinfo, ATMEL_LCDC_CONTRAST_CTR);
1295 	lcdc_writel(sinfo, ATMEL_LCDC_CONTRAST_CTR, 0);
1296 	atmel_lcdfb_power_control(sinfo, 0);
1297 	atmel_lcdfb_stop(sinfo);
1298 	atmel_lcdfb_stop_clock(sinfo);
1299 
1300 	return 0;
1301 }
1302 
1303 static int atmel_lcdfb_resume(struct platform_device *pdev)
1304 {
1305 	struct fb_info *info = platform_get_drvdata(pdev);
1306 	struct atmel_lcdfb_info *sinfo = info->par;
1307 
1308 	atmel_lcdfb_start_clock(sinfo);
1309 	atmel_lcdfb_start(sinfo);
1310 	atmel_lcdfb_power_control(sinfo, 1);
1311 	lcdc_writel(sinfo, ATMEL_LCDC_CONTRAST_CTR, sinfo->saved_lcdcon);
1312 
1313 	/* Enable FIFO & DMA errors */
1314 	lcdc_writel(sinfo, ATMEL_LCDC_IER, ATMEL_LCDC_UFLWI
1315 			| ATMEL_LCDC_OWRI | ATMEL_LCDC_MERI);
1316 
1317 	return 0;
1318 }
1319 
1320 #else
1321 #define atmel_lcdfb_suspend	NULL
1322 #define atmel_lcdfb_resume	NULL
1323 #endif
1324 
1325 static struct platform_driver atmel_lcdfb_driver = {
1326 	.remove		= __exit_p(atmel_lcdfb_remove),
1327 	.suspend	= atmel_lcdfb_suspend,
1328 	.resume		= atmel_lcdfb_resume,
1329 	.driver		= {
1330 		.name	= "atmel_lcdfb",
1331 		.of_match_table	= of_match_ptr(atmel_lcdfb_dt_ids),
1332 	},
1333 };
1334 
1335 module_platform_driver_probe(atmel_lcdfb_driver, atmel_lcdfb_probe);
1336 
1337 MODULE_DESCRIPTION("AT91 LCD Controller framebuffer driver");
1338 MODULE_AUTHOR("Nicolas Ferre <nicolas.ferre@atmel.com>");
1339 MODULE_LICENSE("GPL");
1340