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