1 /*
2  *  Driver for AT91/AT32 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/module.h>
22 #include <linux/platform_data/atmel.h>
23 #include <linux/of.h>
24 #include <linux/of_device.h>
25 #include <linux/of_gpio.h>
26 #include <video/of_display_timing.h>
27 #include <linux/regulator/consumer.h>
28 #include <video/videomode.h>
29 
30 #include <asm/gpio.h>
31 
32 #include <video/atmel_lcdc.h>
33 
34 struct atmel_lcdfb_config {
35 	bool have_alt_pixclock;
36 	bool have_hozval;
37 	bool have_intensity_bit;
38 };
39 
40  /* LCD Controller info data structure, stored in device platform_data */
41 struct atmel_lcdfb_info {
42 	spinlock_t		lock;
43 	struct fb_info		*info;
44 	void __iomem		*mmio;
45 	int			irq_base;
46 	struct work_struct	task;
47 
48 	unsigned int		smem_len;
49 	struct platform_device	*pdev;
50 	struct clk		*bus_clk;
51 	struct clk		*lcdc_clk;
52 
53 	struct backlight_device	*backlight;
54 	u8			bl_power;
55 	u8			saved_lcdcon;
56 
57 	u32			pseudo_palette[16];
58 	bool			have_intensity_bit;
59 
60 	struct atmel_lcdfb_pdata pdata;
61 
62 	struct atmel_lcdfb_config *config;
63 	struct regulator	*reg_lcd;
64 };
65 
66 struct atmel_lcdfb_power_ctrl_gpio {
67 	int gpio;
68 	int active_low;
69 
70 	struct list_head list;
71 };
72 
73 #define lcdc_readl(sinfo, reg)		__raw_readl((sinfo)->mmio+(reg))
74 #define lcdc_writel(sinfo, reg, val)	__raw_writel((val), (sinfo)->mmio+(reg))
75 
76 /* configurable parameters */
77 #define ATMEL_LCDC_CVAL_DEFAULT		0xc8
78 #define ATMEL_LCDC_DMA_BURST_LEN	8	/* words */
79 #define ATMEL_LCDC_FIFO_SIZE		512	/* words */
80 
81 static struct atmel_lcdfb_config at91sam9261_config = {
82 	.have_hozval		= true,
83 	.have_intensity_bit	= true,
84 };
85 
86 static struct atmel_lcdfb_config at91sam9263_config = {
87 	.have_intensity_bit	= true,
88 };
89 
90 static struct atmel_lcdfb_config at91sam9g10_config = {
91 	.have_hozval		= true,
92 };
93 
94 static struct atmel_lcdfb_config at91sam9g45_config = {
95 	.have_alt_pixclock	= true,
96 };
97 
98 static struct atmel_lcdfb_config at91sam9g45es_config = {
99 };
100 
101 static struct atmel_lcdfb_config at91sam9rl_config = {
102 	.have_intensity_bit	= true,
103 };
104 
105 static struct atmel_lcdfb_config at32ap_config = {
106 	.have_hozval		= true,
107 };
108 
109 static const struct platform_device_id atmel_lcdfb_devtypes[] = {
110 	{
111 		.name = "at91sam9261-lcdfb",
112 		.driver_data = (unsigned long)&at91sam9261_config,
113 	}, {
114 		.name = "at91sam9263-lcdfb",
115 		.driver_data = (unsigned long)&at91sam9263_config,
116 	}, {
117 		.name = "at91sam9g10-lcdfb",
118 		.driver_data = (unsigned long)&at91sam9g10_config,
119 	}, {
120 		.name = "at91sam9g45-lcdfb",
121 		.driver_data = (unsigned long)&at91sam9g45_config,
122 	}, {
123 		.name = "at91sam9g45es-lcdfb",
124 		.driver_data = (unsigned long)&at91sam9g45es_config,
125 	}, {
126 		.name = "at91sam9rl-lcdfb",
127 		.driver_data = (unsigned long)&at91sam9rl_config,
128 	}, {
129 		.name = "at32ap-lcdfb",
130 		.driver_data = (unsigned long)&at32ap_config,
131 	}, {
132 		/* terminator */
133 	}
134 };
135 MODULE_DEVICE_TABLE(platform, atmel_lcdfb_devtypes);
136 
137 static struct atmel_lcdfb_config *
138 atmel_lcdfb_get_config(struct platform_device *pdev)
139 {
140 	unsigned long data;
141 
142 	data = platform_get_device_id(pdev)->driver_data;
143 
144 	return (struct atmel_lcdfb_config *)data;
145 }
146 
147 #if defined(CONFIG_ARCH_AT91)
148 #define	ATMEL_LCDFB_FBINFO_DEFAULT	(FBINFO_DEFAULT \
149 					 | FBINFO_PARTIAL_PAN_OK \
150 					 | FBINFO_HWACCEL_YPAN)
151 
152 static inline void atmel_lcdfb_update_dma2d(struct atmel_lcdfb_info *sinfo,
153 					struct fb_var_screeninfo *var,
154 					struct fb_info *info)
155 {
156 
157 }
158 #elif defined(CONFIG_AVR32)
159 #define	ATMEL_LCDFB_FBINFO_DEFAULT	(FBINFO_DEFAULT \
160 					| FBINFO_PARTIAL_PAN_OK \
161 					| FBINFO_HWACCEL_XPAN \
162 					| FBINFO_HWACCEL_YPAN)
163 
164 static void atmel_lcdfb_update_dma2d(struct atmel_lcdfb_info *sinfo,
165 				     struct fb_var_screeninfo *var,
166 				     struct fb_info *info)
167 {
168 	u32 dma2dcfg;
169 	u32 pixeloff;
170 
171 	pixeloff = (var->xoffset * info->var.bits_per_pixel) & 0x1f;
172 
173 	dma2dcfg = (info->var.xres_virtual - info->var.xres)
174 		 * info->var.bits_per_pixel / 8;
175 	dma2dcfg |= pixeloff << ATMEL_LCDC_PIXELOFF_OFFSET;
176 	lcdc_writel(sinfo, ATMEL_LCDC_DMA2DCFG, dma2dcfg);
177 
178 	/* Update configuration */
179 	lcdc_writel(sinfo, ATMEL_LCDC_DMACON,
180 		    lcdc_readl(sinfo, ATMEL_LCDC_DMACON)
181 		    | ATMEL_LCDC_DMAUPDT);
182 }
183 #endif
184 
185 static u32 contrast_ctr = ATMEL_LCDC_PS_DIV8
186 		| ATMEL_LCDC_POL_POSITIVE
187 		| ATMEL_LCDC_ENA_PWMENABLE;
188 
189 #ifdef CONFIG_BACKLIGHT_ATMEL_LCDC
190 
191 /* some bl->props field just changed */
192 static int atmel_bl_update_status(struct backlight_device *bl)
193 {
194 	struct atmel_lcdfb_info *sinfo = bl_get_data(bl);
195 	int			power = sinfo->bl_power;
196 	int			brightness = bl->props.brightness;
197 
198 	/* REVISIT there may be a meaningful difference between
199 	 * fb_blank and power ... there seem to be some cases
200 	 * this doesn't handle correctly.
201 	 */
202 	if (bl->props.fb_blank != sinfo->bl_power)
203 		power = bl->props.fb_blank;
204 	else if (bl->props.power != sinfo->bl_power)
205 		power = bl->props.power;
206 
207 	if (brightness < 0 && power == FB_BLANK_UNBLANK)
208 		brightness = lcdc_readl(sinfo, ATMEL_LCDC_CONTRAST_VAL);
209 	else if (power != FB_BLANK_UNBLANK)
210 		brightness = 0;
211 
212 	lcdc_writel(sinfo, ATMEL_LCDC_CONTRAST_VAL, brightness);
213 	if (contrast_ctr & ATMEL_LCDC_POL_POSITIVE)
214 		lcdc_writel(sinfo, ATMEL_LCDC_CONTRAST_CTR,
215 			brightness ? contrast_ctr : 0);
216 	else
217 		lcdc_writel(sinfo, ATMEL_LCDC_CONTRAST_CTR, contrast_ctr);
218 
219 	bl->props.fb_blank = bl->props.power = sinfo->bl_power = power;
220 
221 	return 0;
222 }
223 
224 static int atmel_bl_get_brightness(struct backlight_device *bl)
225 {
226 	struct atmel_lcdfb_info *sinfo = bl_get_data(bl);
227 
228 	return lcdc_readl(sinfo, ATMEL_LCDC_CONTRAST_VAL);
229 }
230 
231 static const struct backlight_ops atmel_lcdc_bl_ops = {
232 	.update_status = atmel_bl_update_status,
233 	.get_brightness = atmel_bl_get_brightness,
234 };
235 
236 static void init_backlight(struct atmel_lcdfb_info *sinfo)
237 {
238 	struct backlight_properties props;
239 	struct backlight_device	*bl;
240 
241 	sinfo->bl_power = FB_BLANK_UNBLANK;
242 
243 	if (sinfo->backlight)
244 		return;
245 
246 	memset(&props, 0, sizeof(struct backlight_properties));
247 	props.type = BACKLIGHT_RAW;
248 	props.max_brightness = 0xff;
249 	bl = backlight_device_register("backlight", &sinfo->pdev->dev, sinfo,
250 				       &atmel_lcdc_bl_ops, &props);
251 	if (IS_ERR(bl)) {
252 		dev_err(&sinfo->pdev->dev, "error %ld on backlight register\n",
253 				PTR_ERR(bl));
254 		return;
255 	}
256 	sinfo->backlight = bl;
257 
258 	bl->props.power = FB_BLANK_UNBLANK;
259 	bl->props.fb_blank = FB_BLANK_UNBLANK;
260 	bl->props.brightness = atmel_bl_get_brightness(bl);
261 }
262 
263 static void exit_backlight(struct atmel_lcdfb_info *sinfo)
264 {
265 	if (!sinfo->backlight)
266 		return;
267 
268 	if (sinfo->backlight->ops) {
269 		sinfo->backlight->props.power = FB_BLANK_POWERDOWN;
270 		sinfo->backlight->ops->update_status(sinfo->backlight);
271 	}
272 	backlight_device_unregister(sinfo->backlight);
273 }
274 
275 #else
276 
277 static void init_backlight(struct atmel_lcdfb_info *sinfo)
278 {
279 	dev_warn(&sinfo->pdev->dev, "backlight control is not available\n");
280 }
281 
282 static void exit_backlight(struct atmel_lcdfb_info *sinfo)
283 {
284 }
285 
286 #endif
287 
288 static void init_contrast(struct atmel_lcdfb_info *sinfo)
289 {
290 	struct atmel_lcdfb_pdata *pdata = &sinfo->pdata;
291 
292 	/* contrast pwm can be 'inverted' */
293 	if (pdata->lcdcon_pol_negative)
294 		contrast_ctr &= ~(ATMEL_LCDC_POL_POSITIVE);
295 
296 	/* have some default contrast/backlight settings */
297 	lcdc_writel(sinfo, ATMEL_LCDC_CONTRAST_CTR, contrast_ctr);
298 	lcdc_writel(sinfo, ATMEL_LCDC_CONTRAST_VAL, ATMEL_LCDC_CVAL_DEFAULT);
299 
300 	if (pdata->lcdcon_is_backlight)
301 		init_backlight(sinfo);
302 }
303 
304 static inline void atmel_lcdfb_power_control(struct atmel_lcdfb_info *sinfo, int on)
305 {
306 	int ret;
307 	struct atmel_lcdfb_pdata *pdata = &sinfo->pdata;
308 
309 	if (pdata->atmel_lcdfb_power_control)
310 		pdata->atmel_lcdfb_power_control(pdata, on);
311 	else if (sinfo->reg_lcd) {
312 		if (on) {
313 			ret = regulator_enable(sinfo->reg_lcd);
314 			if (ret)
315 				dev_err(&sinfo->pdev->dev,
316 					"lcd regulator enable failed:	%d\n", ret);
317 		} else {
318 			ret = regulator_disable(sinfo->reg_lcd);
319 			if (ret)
320 				dev_err(&sinfo->pdev->dev,
321 					"lcd regulator disable failed: %d\n", ret);
322 		}
323 	}
324 }
325 
326 static struct fb_fix_screeninfo atmel_lcdfb_fix __initdata = {
327 	.type		= FB_TYPE_PACKED_PIXELS,
328 	.visual		= FB_VISUAL_TRUECOLOR,
329 	.xpanstep	= 0,
330 	.ypanstep	= 1,
331 	.ywrapstep	= 0,
332 	.accel		= FB_ACCEL_NONE,
333 };
334 
335 static unsigned long compute_hozval(struct atmel_lcdfb_info *sinfo,
336 							unsigned long xres)
337 {
338 	unsigned long lcdcon2;
339 	unsigned long value;
340 
341 	if (!sinfo->config->have_hozval)
342 		return xres;
343 
344 	lcdcon2 = lcdc_readl(sinfo, ATMEL_LCDC_LCDCON2);
345 	value = xres;
346 	if ((lcdcon2 & ATMEL_LCDC_DISTYPE) != ATMEL_LCDC_DISTYPE_TFT) {
347 		/* STN display */
348 		if ((lcdcon2 & ATMEL_LCDC_DISTYPE) == ATMEL_LCDC_DISTYPE_STNCOLOR) {
349 			value *= 3;
350 		}
351 		if ( (lcdcon2 & ATMEL_LCDC_IFWIDTH) == ATMEL_LCDC_IFWIDTH_4
352 		   || ( (lcdcon2 & ATMEL_LCDC_IFWIDTH) == ATMEL_LCDC_IFWIDTH_8
353 		      && (lcdcon2 & ATMEL_LCDC_SCANMOD) == ATMEL_LCDC_SCANMOD_DUAL ))
354 			value = DIV_ROUND_UP(value, 4);
355 		else
356 			value = DIV_ROUND_UP(value, 8);
357 	}
358 
359 	return value;
360 }
361 
362 static void atmel_lcdfb_stop_nowait(struct atmel_lcdfb_info *sinfo)
363 {
364 	struct atmel_lcdfb_pdata *pdata = &sinfo->pdata;
365 
366 	/* Turn off the LCD controller and the DMA controller */
367 	lcdc_writel(sinfo, ATMEL_LCDC_PWRCON,
368 			pdata->guard_time << ATMEL_LCDC_GUARDT_OFFSET);
369 
370 	/* Wait for the LCDC core to become idle */
371 	while (lcdc_readl(sinfo, ATMEL_LCDC_PWRCON) & ATMEL_LCDC_BUSY)
372 		msleep(10);
373 
374 	lcdc_writel(sinfo, ATMEL_LCDC_DMACON, 0);
375 }
376 
377 static void atmel_lcdfb_stop(struct atmel_lcdfb_info *sinfo)
378 {
379 	atmel_lcdfb_stop_nowait(sinfo);
380 
381 	/* Wait for DMA engine to become idle... */
382 	while (lcdc_readl(sinfo, ATMEL_LCDC_DMACON) & ATMEL_LCDC_DMABUSY)
383 		msleep(10);
384 }
385 
386 static void atmel_lcdfb_start(struct atmel_lcdfb_info *sinfo)
387 {
388 	struct atmel_lcdfb_pdata *pdata = &sinfo->pdata;
389 
390 	lcdc_writel(sinfo, ATMEL_LCDC_DMACON, pdata->default_dmacon);
391 	lcdc_writel(sinfo, ATMEL_LCDC_PWRCON,
392 		(pdata->guard_time << ATMEL_LCDC_GUARDT_OFFSET)
393 		| ATMEL_LCDC_PWR);
394 }
395 
396 static void atmel_lcdfb_update_dma(struct fb_info *info,
397 			       struct fb_var_screeninfo *var)
398 {
399 	struct atmel_lcdfb_info *sinfo = info->par;
400 	struct fb_fix_screeninfo *fix = &info->fix;
401 	unsigned long dma_addr;
402 
403 	dma_addr = (fix->smem_start + var->yoffset * fix->line_length
404 		    + var->xoffset * info->var.bits_per_pixel / 8);
405 
406 	dma_addr &= ~3UL;
407 
408 	/* Set framebuffer DMA base address and pixel offset */
409 	lcdc_writel(sinfo, ATMEL_LCDC_DMABADDR1, dma_addr);
410 
411 	atmel_lcdfb_update_dma2d(sinfo, var, info);
412 }
413 
414 static inline void atmel_lcdfb_free_video_memory(struct atmel_lcdfb_info *sinfo)
415 {
416 	struct fb_info *info = sinfo->info;
417 
418 	dma_free_writecombine(info->device, info->fix.smem_len,
419 				info->screen_base, info->fix.smem_start);
420 }
421 
422 /**
423  *	atmel_lcdfb_alloc_video_memory - Allocate framebuffer memory
424  *	@sinfo: the frame buffer to allocate memory for
425  *
426  * 	This function is called only from the atmel_lcdfb_probe()
427  * 	so no locking by fb_info->mm_lock around smem_len setting is needed.
428  */
429 static int atmel_lcdfb_alloc_video_memory(struct atmel_lcdfb_info *sinfo)
430 {
431 	struct fb_info *info = sinfo->info;
432 	struct fb_var_screeninfo *var = &info->var;
433 	unsigned int smem_len;
434 
435 	smem_len = (var->xres_virtual * var->yres_virtual
436 		    * ((var->bits_per_pixel + 7) / 8));
437 	info->fix.smem_len = max(smem_len, sinfo->smem_len);
438 
439 	info->screen_base = dma_alloc_writecombine(info->device, info->fix.smem_len,
440 					(dma_addr_t *)&info->fix.smem_start, GFP_KERNEL);
441 
442 	if (!info->screen_base) {
443 		return -ENOMEM;
444 	}
445 
446 	memset(info->screen_base, 0, info->fix.smem_len);
447 
448 	return 0;
449 }
450 
451 static const struct fb_videomode *atmel_lcdfb_choose_mode(struct fb_var_screeninfo *var,
452 						     struct fb_info *info)
453 {
454 	struct fb_videomode varfbmode;
455 	const struct fb_videomode *fbmode = NULL;
456 
457 	fb_var_to_videomode(&varfbmode, var);
458 	fbmode = fb_find_nearest_mode(&varfbmode, &info->modelist);
459 	if (fbmode)
460 		fb_videomode_to_var(var, fbmode);
461 	return fbmode;
462 }
463 
464 
465 /**
466  *      atmel_lcdfb_check_var - Validates a var passed in.
467  *      @var: frame buffer variable screen structure
468  *      @info: frame buffer structure that represents a single frame buffer
469  *
470  *	Checks to see if the hardware supports the state requested by
471  *	var passed in. This function does not alter the hardware
472  *	state!!!  This means the data stored in struct fb_info and
473  *	struct atmel_lcdfb_info do not change. This includes the var
474  *	inside of struct fb_info.  Do NOT change these. This function
475  *	can be called on its own if we intent to only test a mode and
476  *	not actually set it. The stuff in modedb.c is a example of
477  *	this. If the var passed in is slightly off by what the
478  *	hardware can support then we alter the var PASSED in to what
479  *	we can do. If the hardware doesn't support mode change a
480  *	-EINVAL will be returned by the upper layers. You don't need
481  *	to implement this function then. If you hardware doesn't
482  *	support changing the resolution then this function is not
483  *	needed. In this case the driver would just provide a var that
484  *	represents the static state the screen is in.
485  *
486  *	Returns negative errno on error, or zero on success.
487  */
488 static int atmel_lcdfb_check_var(struct fb_var_screeninfo *var,
489 			     struct fb_info *info)
490 {
491 	struct device *dev = info->device;
492 	struct atmel_lcdfb_info *sinfo = info->par;
493 	struct atmel_lcdfb_pdata *pdata = &sinfo->pdata;
494 	unsigned long clk_value_khz;
495 
496 	clk_value_khz = clk_get_rate(sinfo->lcdc_clk) / 1000;
497 
498 	dev_dbg(dev, "%s:\n", __func__);
499 
500 	if (!(var->pixclock && var->bits_per_pixel)) {
501 		/* choose a suitable mode if possible */
502 		if (!atmel_lcdfb_choose_mode(var, info)) {
503 			dev_err(dev, "needed value not specified\n");
504 			return -EINVAL;
505 		}
506 	}
507 
508 	dev_dbg(dev, "  resolution: %ux%u\n", var->xres, var->yres);
509 	dev_dbg(dev, "  pixclk:     %lu KHz\n", PICOS2KHZ(var->pixclock));
510 	dev_dbg(dev, "  bpp:        %u\n", var->bits_per_pixel);
511 	dev_dbg(dev, "  clk:        %lu KHz\n", clk_value_khz);
512 
513 	if (PICOS2KHZ(var->pixclock) > clk_value_khz) {
514 		dev_err(dev, "%lu KHz pixel clock is too fast\n", PICOS2KHZ(var->pixclock));
515 		return -EINVAL;
516 	}
517 
518 	/* Do not allow to have real resoulution larger than virtual */
519 	if (var->xres > var->xres_virtual)
520 		var->xres_virtual = var->xres;
521 
522 	if (var->yres > var->yres_virtual)
523 		var->yres_virtual = var->yres;
524 
525 	/* Force same alignment for each line */
526 	var->xres = (var->xres + 3) & ~3UL;
527 	var->xres_virtual = (var->xres_virtual + 3) & ~3UL;
528 
529 	var->red.msb_right = var->green.msb_right = var->blue.msb_right = 0;
530 	var->transp.msb_right = 0;
531 	var->transp.offset = var->transp.length = 0;
532 	var->xoffset = var->yoffset = 0;
533 
534 	if (info->fix.smem_len) {
535 		unsigned int smem_len = (var->xres_virtual * var->yres_virtual
536 					 * ((var->bits_per_pixel + 7) / 8));
537 		if (smem_len > info->fix.smem_len) {
538 			dev_err(dev, "Frame buffer is too small (%u) for screen size (need at least %u)\n",
539 				info->fix.smem_len, smem_len);
540 			return -EINVAL;
541 		}
542 	}
543 
544 	/* Saturate vertical and horizontal timings at maximum values */
545 	var->vsync_len = min_t(u32, var->vsync_len,
546 			(ATMEL_LCDC_VPW >> ATMEL_LCDC_VPW_OFFSET) + 1);
547 	var->upper_margin = min_t(u32, var->upper_margin,
548 			ATMEL_LCDC_VBP >> ATMEL_LCDC_VBP_OFFSET);
549 	var->lower_margin = min_t(u32, var->lower_margin,
550 			ATMEL_LCDC_VFP);
551 	var->right_margin = min_t(u32, var->right_margin,
552 			(ATMEL_LCDC_HFP >> ATMEL_LCDC_HFP_OFFSET) + 1);
553 	var->hsync_len = min_t(u32, var->hsync_len,
554 			(ATMEL_LCDC_HPW >> ATMEL_LCDC_HPW_OFFSET) + 1);
555 	var->left_margin = min_t(u32, var->left_margin,
556 			ATMEL_LCDC_HBP + 1);
557 
558 	/* Some parameters can't be zero */
559 	var->vsync_len = max_t(u32, var->vsync_len, 1);
560 	var->right_margin = max_t(u32, var->right_margin, 1);
561 	var->hsync_len = max_t(u32, var->hsync_len, 1);
562 	var->left_margin = max_t(u32, var->left_margin, 1);
563 
564 	switch (var->bits_per_pixel) {
565 	case 1:
566 	case 2:
567 	case 4:
568 	case 8:
569 		var->red.offset = var->green.offset = var->blue.offset = 0;
570 		var->red.length = var->green.length = var->blue.length
571 			= var->bits_per_pixel;
572 		break;
573 	case 16:
574 		/* Older SOCs use IBGR:555 rather than BGR:565. */
575 		if (sinfo->config->have_intensity_bit)
576 			var->green.length = 5;
577 		else
578 			var->green.length = 6;
579 
580 		if (pdata->lcd_wiring_mode == ATMEL_LCDC_WIRING_RGB) {
581 			/* RGB:5X5 mode */
582 			var->red.offset = var->green.length + 5;
583 			var->blue.offset = 0;
584 		} else {
585 			/* BGR:5X5 mode */
586 			var->red.offset = 0;
587 			var->blue.offset = var->green.length + 5;
588 		}
589 		var->green.offset = 5;
590 		var->red.length = var->blue.length = 5;
591 		break;
592 	case 32:
593 		var->transp.offset = 24;
594 		var->transp.length = 8;
595 		/* fall through */
596 	case 24:
597 		if (pdata->lcd_wiring_mode == ATMEL_LCDC_WIRING_RGB) {
598 			/* RGB:888 mode */
599 			var->red.offset = 16;
600 			var->blue.offset = 0;
601 		} else {
602 			/* BGR:888 mode */
603 			var->red.offset = 0;
604 			var->blue.offset = 16;
605 		}
606 		var->green.offset = 8;
607 		var->red.length = var->green.length = var->blue.length = 8;
608 		break;
609 	default:
610 		dev_err(dev, "color depth %d not supported\n",
611 					var->bits_per_pixel);
612 		return -EINVAL;
613 	}
614 
615 	return 0;
616 }
617 
618 /*
619  * LCD reset sequence
620  */
621 static void atmel_lcdfb_reset(struct atmel_lcdfb_info *sinfo)
622 {
623 	might_sleep();
624 
625 	atmel_lcdfb_stop(sinfo);
626 	atmel_lcdfb_start(sinfo);
627 }
628 
629 /**
630  *      atmel_lcdfb_set_par - Alters the hardware state.
631  *      @info: frame buffer structure that represents a single frame buffer
632  *
633  *	Using the fb_var_screeninfo in fb_info we set the resolution
634  *	of the this particular framebuffer. This function alters the
635  *	par AND the fb_fix_screeninfo stored in fb_info. It doesn't
636  *	not alter var in fb_info since we are using that data. This
637  *	means we depend on the data in var inside fb_info to be
638  *	supported by the hardware.  atmel_lcdfb_check_var is always called
639  *	before atmel_lcdfb_set_par to ensure this.  Again if you can't
640  *	change the resolution you don't need this function.
641  *
642  */
643 static int atmel_lcdfb_set_par(struct fb_info *info)
644 {
645 	struct atmel_lcdfb_info *sinfo = info->par;
646 	struct atmel_lcdfb_pdata *pdata = &sinfo->pdata;
647 	unsigned long hozval_linesz;
648 	unsigned long value;
649 	unsigned long clk_value_khz;
650 	unsigned long bits_per_line;
651 	unsigned long pix_factor = 2;
652 
653 	might_sleep();
654 
655 	dev_dbg(info->device, "%s:\n", __func__);
656 	dev_dbg(info->device, "  * resolution: %ux%u (%ux%u virtual)\n",
657 		 info->var.xres, info->var.yres,
658 		 info->var.xres_virtual, info->var.yres_virtual);
659 
660 	atmel_lcdfb_stop_nowait(sinfo);
661 
662 	if (info->var.bits_per_pixel == 1)
663 		info->fix.visual = FB_VISUAL_MONO01;
664 	else if (info->var.bits_per_pixel <= 8)
665 		info->fix.visual = FB_VISUAL_PSEUDOCOLOR;
666 	else
667 		info->fix.visual = FB_VISUAL_TRUECOLOR;
668 
669 	bits_per_line = info->var.xres_virtual * info->var.bits_per_pixel;
670 	info->fix.line_length = DIV_ROUND_UP(bits_per_line, 8);
671 
672 	/* Re-initialize the DMA engine... */
673 	dev_dbg(info->device, "  * update DMA engine\n");
674 	atmel_lcdfb_update_dma(info, &info->var);
675 
676 	/* ...set frame size and burst length = 8 words (?) */
677 	value = (info->var.yres * info->var.xres * info->var.bits_per_pixel) / 32;
678 	value |= ((ATMEL_LCDC_DMA_BURST_LEN - 1) << ATMEL_LCDC_BLENGTH_OFFSET);
679 	lcdc_writel(sinfo, ATMEL_LCDC_DMAFRMCFG, value);
680 
681 	/* Now, the LCDC core... */
682 
683 	/* Set pixel clock */
684 	if (sinfo->config->have_alt_pixclock)
685 		pix_factor = 1;
686 
687 	clk_value_khz = clk_get_rate(sinfo->lcdc_clk) / 1000;
688 
689 	value = DIV_ROUND_UP(clk_value_khz, PICOS2KHZ(info->var.pixclock));
690 
691 	if (value < pix_factor) {
692 		dev_notice(info->device, "Bypassing pixel clock divider\n");
693 		lcdc_writel(sinfo, ATMEL_LCDC_LCDCON1, ATMEL_LCDC_BYPASS);
694 	} else {
695 		value = (value / pix_factor) - 1;
696 		dev_dbg(info->device, "  * programming CLKVAL = 0x%08lx\n",
697 				value);
698 		lcdc_writel(sinfo, ATMEL_LCDC_LCDCON1,
699 				value << ATMEL_LCDC_CLKVAL_OFFSET);
700 		info->var.pixclock =
701 			KHZ2PICOS(clk_value_khz / (pix_factor * (value + 1)));
702 		dev_dbg(info->device, "  updated pixclk:     %lu KHz\n",
703 					PICOS2KHZ(info->var.pixclock));
704 	}
705 
706 
707 	/* Initialize control register 2 */
708 	value = pdata->default_lcdcon2;
709 
710 	if (!(info->var.sync & FB_SYNC_HOR_HIGH_ACT))
711 		value |= ATMEL_LCDC_INVLINE_INVERTED;
712 	if (!(info->var.sync & FB_SYNC_VERT_HIGH_ACT))
713 		value |= ATMEL_LCDC_INVFRAME_INVERTED;
714 
715 	switch (info->var.bits_per_pixel) {
716 		case 1:	value |= ATMEL_LCDC_PIXELSIZE_1; break;
717 		case 2: value |= ATMEL_LCDC_PIXELSIZE_2; break;
718 		case 4: value |= ATMEL_LCDC_PIXELSIZE_4; break;
719 		case 8: value |= ATMEL_LCDC_PIXELSIZE_8; break;
720 		case 15: /* fall through */
721 		case 16: value |= ATMEL_LCDC_PIXELSIZE_16; break;
722 		case 24: value |= ATMEL_LCDC_PIXELSIZE_24; break;
723 		case 32: value |= ATMEL_LCDC_PIXELSIZE_32; break;
724 		default: BUG(); break;
725 	}
726 	dev_dbg(info->device, "  * LCDCON2 = %08lx\n", value);
727 	lcdc_writel(sinfo, ATMEL_LCDC_LCDCON2, value);
728 
729 	/* Vertical timing */
730 	value = (info->var.vsync_len - 1) << ATMEL_LCDC_VPW_OFFSET;
731 	value |= info->var.upper_margin << ATMEL_LCDC_VBP_OFFSET;
732 	value |= info->var.lower_margin;
733 	dev_dbg(info->device, "  * LCDTIM1 = %08lx\n", value);
734 	lcdc_writel(sinfo, ATMEL_LCDC_TIM1, value);
735 
736 	/* Horizontal timing */
737 	value = (info->var.right_margin - 1) << ATMEL_LCDC_HFP_OFFSET;
738 	value |= (info->var.hsync_len - 1) << ATMEL_LCDC_HPW_OFFSET;
739 	value |= (info->var.left_margin - 1);
740 	dev_dbg(info->device, "  * LCDTIM2 = %08lx\n", value);
741 	lcdc_writel(sinfo, ATMEL_LCDC_TIM2, value);
742 
743 	/* Horizontal value (aka line size) */
744 	hozval_linesz = compute_hozval(sinfo, info->var.xres);
745 
746 	/* Display size */
747 	value = (hozval_linesz - 1) << ATMEL_LCDC_HOZVAL_OFFSET;
748 	value |= info->var.yres - 1;
749 	dev_dbg(info->device, "  * LCDFRMCFG = %08lx\n", value);
750 	lcdc_writel(sinfo, ATMEL_LCDC_LCDFRMCFG, value);
751 
752 	/* FIFO Threshold: Use formula from data sheet */
753 	value = ATMEL_LCDC_FIFO_SIZE - (2 * ATMEL_LCDC_DMA_BURST_LEN + 3);
754 	lcdc_writel(sinfo, ATMEL_LCDC_FIFO, value);
755 
756 	/* Toggle LCD_MODE every frame */
757 	lcdc_writel(sinfo, ATMEL_LCDC_MVAL, 0);
758 
759 	/* Disable all interrupts */
760 	lcdc_writel(sinfo, ATMEL_LCDC_IDR, ~0UL);
761 	/* Enable FIFO & DMA errors */
762 	lcdc_writel(sinfo, ATMEL_LCDC_IER, ATMEL_LCDC_UFLWI | ATMEL_LCDC_OWRI | ATMEL_LCDC_MERI);
763 
764 	/* ...wait for DMA engine to become idle... */
765 	while (lcdc_readl(sinfo, ATMEL_LCDC_DMACON) & ATMEL_LCDC_DMABUSY)
766 		msleep(10);
767 
768 	atmel_lcdfb_start(sinfo);
769 
770 	dev_dbg(info->device, "  * DONE\n");
771 
772 	return 0;
773 }
774 
775 static inline unsigned int chan_to_field(unsigned int chan, const struct fb_bitfield *bf)
776 {
777 	chan &= 0xffff;
778 	chan >>= 16 - bf->length;
779 	return chan << bf->offset;
780 }
781 
782 /**
783  *  	atmel_lcdfb_setcolreg - Optional function. Sets a color register.
784  *      @regno: Which register in the CLUT we are programming
785  *      @red: The red value which can be up to 16 bits wide
786  *	@green: The green value which can be up to 16 bits wide
787  *	@blue:  The blue value which can be up to 16 bits wide.
788  *	@transp: If supported the alpha value which can be up to 16 bits wide.
789  *      @info: frame buffer info structure
790  *
791  *  	Set a single color register. The values supplied have a 16 bit
792  *  	magnitude which needs to be scaled in this function for the hardware.
793  *	Things to take into consideration are how many color registers, if
794  *	any, are supported with the current color visual. With truecolor mode
795  *	no color palettes are supported. Here a pseudo palette is created
796  *	which we store the value in pseudo_palette in struct fb_info. For
797  *	pseudocolor mode we have a limited color palette. To deal with this
798  *	we can program what color is displayed for a particular pixel value.
799  *	DirectColor is similar in that we can program each color field. If
800  *	we have a static colormap we don't need to implement this function.
801  *
802  *	Returns negative errno on error, or zero on success. In an
803  *	ideal world, this would have been the case, but as it turns
804  *	out, the other drivers return 1 on failure, so that's what
805  *	we're going to do.
806  */
807 static int atmel_lcdfb_setcolreg(unsigned int regno, unsigned int red,
808 			     unsigned int green, unsigned int blue,
809 			     unsigned int transp, struct fb_info *info)
810 {
811 	struct atmel_lcdfb_info *sinfo = info->par;
812 	struct atmel_lcdfb_pdata *pdata = &sinfo->pdata;
813 	unsigned int val;
814 	u32 *pal;
815 	int ret = 1;
816 
817 	if (info->var.grayscale)
818 		red = green = blue = (19595 * red + 38470 * green
819 				      + 7471 * blue) >> 16;
820 
821 	switch (info->fix.visual) {
822 	case FB_VISUAL_TRUECOLOR:
823 		if (regno < 16) {
824 			pal = info->pseudo_palette;
825 
826 			val  = chan_to_field(red, &info->var.red);
827 			val |= chan_to_field(green, &info->var.green);
828 			val |= chan_to_field(blue, &info->var.blue);
829 
830 			pal[regno] = val;
831 			ret = 0;
832 		}
833 		break;
834 
835 	case FB_VISUAL_PSEUDOCOLOR:
836 		if (regno < 256) {
837 			if (sinfo->config->have_intensity_bit) {
838 				/* old style I+BGR:555 */
839 				val  = ((red   >> 11) & 0x001f);
840 				val |= ((green >>  6) & 0x03e0);
841 				val |= ((blue  >>  1) & 0x7c00);
842 
843 				/*
844 				 * TODO: intensity bit. Maybe something like
845 				 *   ~(red[10] ^ green[10] ^ blue[10]) & 1
846 				 */
847 			} else {
848 				/* new style BGR:565 / RGB:565 */
849 				if (pdata->lcd_wiring_mode == ATMEL_LCDC_WIRING_RGB) {
850 					val  = ((blue >> 11) & 0x001f);
851 					val |= ((red  >>  0) & 0xf800);
852 				} else {
853 					val  = ((red  >> 11) & 0x001f);
854 					val |= ((blue >>  0) & 0xf800);
855 				}
856 
857 				val |= ((green >>  5) & 0x07e0);
858 			}
859 
860 			lcdc_writel(sinfo, ATMEL_LCDC_LUT(regno), val);
861 			ret = 0;
862 		}
863 		break;
864 
865 	case FB_VISUAL_MONO01:
866 		if (regno < 2) {
867 			val = (regno == 0) ? 0x00 : 0x1F;
868 			lcdc_writel(sinfo, ATMEL_LCDC_LUT(regno), val);
869 			ret = 0;
870 		}
871 		break;
872 
873 	}
874 
875 	return ret;
876 }
877 
878 static int atmel_lcdfb_pan_display(struct fb_var_screeninfo *var,
879 			       struct fb_info *info)
880 {
881 	dev_dbg(info->device, "%s\n", __func__);
882 
883 	atmel_lcdfb_update_dma(info, var);
884 
885 	return 0;
886 }
887 
888 static int atmel_lcdfb_blank(int blank_mode, struct fb_info *info)
889 {
890 	struct atmel_lcdfb_info *sinfo = info->par;
891 
892 	switch (blank_mode) {
893 	case FB_BLANK_UNBLANK:
894 	case FB_BLANK_NORMAL:
895 		atmel_lcdfb_start(sinfo);
896 		break;
897 	case FB_BLANK_VSYNC_SUSPEND:
898 	case FB_BLANK_HSYNC_SUSPEND:
899 		break;
900 	case FB_BLANK_POWERDOWN:
901 		atmel_lcdfb_stop(sinfo);
902 		break;
903 	default:
904 		return -EINVAL;
905 	}
906 
907 	/* let fbcon do a soft blank for us */
908 	return ((blank_mode == FB_BLANK_NORMAL) ? 1 : 0);
909 }
910 
911 static struct fb_ops atmel_lcdfb_ops = {
912 	.owner		= THIS_MODULE,
913 	.fb_check_var	= atmel_lcdfb_check_var,
914 	.fb_set_par	= atmel_lcdfb_set_par,
915 	.fb_setcolreg	= atmel_lcdfb_setcolreg,
916 	.fb_blank	= atmel_lcdfb_blank,
917 	.fb_pan_display	= atmel_lcdfb_pan_display,
918 	.fb_fillrect	= cfb_fillrect,
919 	.fb_copyarea	= cfb_copyarea,
920 	.fb_imageblit	= cfb_imageblit,
921 };
922 
923 static irqreturn_t atmel_lcdfb_interrupt(int irq, void *dev_id)
924 {
925 	struct fb_info *info = dev_id;
926 	struct atmel_lcdfb_info *sinfo = info->par;
927 	u32 status;
928 
929 	status = lcdc_readl(sinfo, ATMEL_LCDC_ISR);
930 	if (status & ATMEL_LCDC_UFLWI) {
931 		dev_warn(info->device, "FIFO underflow %#x\n", status);
932 		/* reset DMA and FIFO to avoid screen shifting */
933 		schedule_work(&sinfo->task);
934 	}
935 	lcdc_writel(sinfo, ATMEL_LCDC_ICR, status);
936 	return IRQ_HANDLED;
937 }
938 
939 /*
940  * LCD controller task (to reset the LCD)
941  */
942 static void atmel_lcdfb_task(struct work_struct *work)
943 {
944 	struct atmel_lcdfb_info *sinfo =
945 		container_of(work, struct atmel_lcdfb_info, task);
946 
947 	atmel_lcdfb_reset(sinfo);
948 }
949 
950 static int __init atmel_lcdfb_init_fbinfo(struct atmel_lcdfb_info *sinfo)
951 {
952 	struct fb_info *info = sinfo->info;
953 	int ret = 0;
954 
955 	info->var.activate |= FB_ACTIVATE_FORCE | FB_ACTIVATE_NOW;
956 
957 	dev_info(info->device,
958 	       "%luKiB frame buffer at %08lx (mapped at %p)\n",
959 	       (unsigned long)info->fix.smem_len / 1024,
960 	       (unsigned long)info->fix.smem_start,
961 	       info->screen_base);
962 
963 	/* Allocate colormap */
964 	ret = fb_alloc_cmap(&info->cmap, 256, 0);
965 	if (ret < 0)
966 		dev_err(info->device, "Alloc color map failed\n");
967 
968 	return ret;
969 }
970 
971 static void atmel_lcdfb_start_clock(struct atmel_lcdfb_info *sinfo)
972 {
973 	clk_prepare_enable(sinfo->bus_clk);
974 	clk_prepare_enable(sinfo->lcdc_clk);
975 }
976 
977 static void atmel_lcdfb_stop_clock(struct atmel_lcdfb_info *sinfo)
978 {
979 	clk_disable_unprepare(sinfo->bus_clk);
980 	clk_disable_unprepare(sinfo->lcdc_clk);
981 }
982 
983 #ifdef CONFIG_OF
984 static const struct of_device_id atmel_lcdfb_dt_ids[] = {
985 	{ .compatible = "atmel,at91sam9261-lcdc" , .data = &at91sam9261_config, },
986 	{ .compatible = "atmel,at91sam9263-lcdc" , .data = &at91sam9263_config, },
987 	{ .compatible = "atmel,at91sam9g10-lcdc" , .data = &at91sam9g10_config, },
988 	{ .compatible = "atmel,at91sam9g45-lcdc" , .data = &at91sam9g45_config, },
989 	{ .compatible = "atmel,at91sam9g45es-lcdc" , .data = &at91sam9g45es_config, },
990 	{ .compatible = "atmel,at91sam9rl-lcdc" , .data = &at91sam9rl_config, },
991 	{ .compatible = "atmel,at32ap-lcdc" , .data = &at32ap_config, },
992 	{ /* sentinel */ }
993 };
994 
995 MODULE_DEVICE_TABLE(of, atmel_lcdfb_dt_ids);
996 
997 static const char *atmel_lcdfb_wiring_modes[] = {
998 	[ATMEL_LCDC_WIRING_BGR]	= "BRG",
999 	[ATMEL_LCDC_WIRING_RGB]	= "RGB",
1000 };
1001 
1002 const int atmel_lcdfb_get_of_wiring_modes(struct device_node *np)
1003 {
1004 	const char *mode;
1005 	int err, i;
1006 
1007 	err = of_property_read_string(np, "atmel,lcd-wiring-mode", &mode);
1008 	if (err < 0)
1009 		return ATMEL_LCDC_WIRING_BGR;
1010 
1011 	for (i = 0; i < ARRAY_SIZE(atmel_lcdfb_wiring_modes); i++)
1012 		if (!strcasecmp(mode, atmel_lcdfb_wiring_modes[i]))
1013 			return i;
1014 
1015 	return -ENODEV;
1016 }
1017 
1018 static void atmel_lcdfb_power_control_gpio(struct atmel_lcdfb_pdata *pdata, int on)
1019 {
1020 	struct atmel_lcdfb_power_ctrl_gpio *og;
1021 
1022 	list_for_each_entry(og, &pdata->pwr_gpios, list)
1023 		gpio_set_value(og->gpio, on);
1024 }
1025 
1026 static int atmel_lcdfb_of_init(struct atmel_lcdfb_info *sinfo)
1027 {
1028 	struct fb_info *info = sinfo->info;
1029 	struct atmel_lcdfb_pdata *pdata = &sinfo->pdata;
1030 	struct fb_var_screeninfo *var = &info->var;
1031 	struct device *dev = &sinfo->pdev->dev;
1032 	struct device_node *np =dev->of_node;
1033 	struct device_node *display_np;
1034 	struct device_node *timings_np;
1035 	struct display_timings *timings;
1036 	enum of_gpio_flags flags;
1037 	struct atmel_lcdfb_power_ctrl_gpio *og;
1038 	bool is_gpio_power = false;
1039 	int ret = -ENOENT;
1040 	int i, gpio;
1041 
1042 	sinfo->config = (struct atmel_lcdfb_config*)
1043 		of_match_device(atmel_lcdfb_dt_ids, dev)->data;
1044 
1045 	display_np = of_parse_phandle(np, "display", 0);
1046 	if (!display_np) {
1047 		dev_err(dev, "failed to find display phandle\n");
1048 		return -ENOENT;
1049 	}
1050 
1051 	ret = of_property_read_u32(display_np, "bits-per-pixel", &var->bits_per_pixel);
1052 	if (ret < 0) {
1053 		dev_err(dev, "failed to get property bits-per-pixel\n");
1054 		goto put_display_node;
1055 	}
1056 
1057 	ret = of_property_read_u32(display_np, "atmel,guard-time", &pdata->guard_time);
1058 	if (ret < 0) {
1059 		dev_err(dev, "failed to get property atmel,guard-time\n");
1060 		goto put_display_node;
1061 	}
1062 
1063 	ret = of_property_read_u32(display_np, "atmel,lcdcon2", &pdata->default_lcdcon2);
1064 	if (ret < 0) {
1065 		dev_err(dev, "failed to get property atmel,lcdcon2\n");
1066 		goto put_display_node;
1067 	}
1068 
1069 	ret = of_property_read_u32(display_np, "atmel,dmacon", &pdata->default_dmacon);
1070 	if (ret < 0) {
1071 		dev_err(dev, "failed to get property bits-per-pixel\n");
1072 		goto put_display_node;
1073 	}
1074 
1075 	INIT_LIST_HEAD(&pdata->pwr_gpios);
1076 	ret = -ENOMEM;
1077 	for (i = 0; i < of_gpio_named_count(display_np, "atmel,power-control-gpio"); i++) {
1078 		gpio = of_get_named_gpio_flags(display_np, "atmel,power-control-gpio",
1079 					       i, &flags);
1080 		if (gpio < 0)
1081 			continue;
1082 
1083 		og = devm_kzalloc(dev, sizeof(*og), GFP_KERNEL);
1084 		if (!og)
1085 			goto put_display_node;
1086 
1087 		og->gpio = gpio;
1088 		og->active_low = flags & OF_GPIO_ACTIVE_LOW;
1089 		is_gpio_power = true;
1090 		ret = devm_gpio_request(dev, gpio, "lcd-power-control-gpio");
1091 		if (ret) {
1092 			dev_err(dev, "request gpio %d failed\n", gpio);
1093 			goto put_display_node;
1094 		}
1095 
1096 		ret = gpio_direction_output(gpio, og->active_low);
1097 		if (ret) {
1098 			dev_err(dev, "set direction output gpio %d failed\n", gpio);
1099 			goto put_display_node;
1100 		}
1101 		list_add(&og->list, &pdata->pwr_gpios);
1102 	}
1103 
1104 	if (is_gpio_power)
1105 		pdata->atmel_lcdfb_power_control = atmel_lcdfb_power_control_gpio;
1106 
1107 	ret = atmel_lcdfb_get_of_wiring_modes(display_np);
1108 	if (ret < 0) {
1109 		dev_err(dev, "invalid atmel,lcd-wiring-mode\n");
1110 		goto put_display_node;
1111 	}
1112 	pdata->lcd_wiring_mode = ret;
1113 
1114 	pdata->lcdcon_is_backlight = of_property_read_bool(display_np, "atmel,lcdcon-backlight");
1115 	pdata->lcdcon_pol_negative = of_property_read_bool(display_np, "atmel,lcdcon-backlight-inverted");
1116 
1117 	timings = of_get_display_timings(display_np);
1118 	if (!timings) {
1119 		dev_err(dev, "failed to get display timings\n");
1120 		ret = -EINVAL;
1121 		goto put_display_node;
1122 	}
1123 
1124 	timings_np = of_find_node_by_name(display_np, "display-timings");
1125 	if (!timings_np) {
1126 		dev_err(dev, "failed to find display-timings node\n");
1127 		ret = -ENODEV;
1128 		goto put_display_node;
1129 	}
1130 
1131 	for (i = 0; i < of_get_child_count(timings_np); i++) {
1132 		struct videomode vm;
1133 		struct fb_videomode fb_vm;
1134 
1135 		ret = videomode_from_timings(timings, &vm, i);
1136 		if (ret < 0)
1137 			goto put_timings_node;
1138 		ret = fb_videomode_from_videomode(&vm, &fb_vm);
1139 		if (ret < 0)
1140 			goto put_timings_node;
1141 
1142 		fb_add_videomode(&fb_vm, &info->modelist);
1143 	}
1144 
1145 	return 0;
1146 
1147 put_timings_node:
1148 	of_node_put(timings_np);
1149 put_display_node:
1150 	of_node_put(display_np);
1151 	return ret;
1152 }
1153 #else
1154 static int atmel_lcdfb_of_init(struct atmel_lcdfb_info *sinfo)
1155 {
1156 	return 0;
1157 }
1158 #endif
1159 
1160 static int __init atmel_lcdfb_probe(struct platform_device *pdev)
1161 {
1162 	struct device *dev = &pdev->dev;
1163 	struct fb_info *info;
1164 	struct atmel_lcdfb_info *sinfo;
1165 	struct atmel_lcdfb_pdata *pdata = NULL;
1166 	struct resource *regs = NULL;
1167 	struct resource *map = NULL;
1168 	struct fb_modelist *modelist;
1169 	int ret;
1170 
1171 	dev_dbg(dev, "%s BEGIN\n", __func__);
1172 
1173 	ret = -ENOMEM;
1174 	info = framebuffer_alloc(sizeof(struct atmel_lcdfb_info), dev);
1175 	if (!info) {
1176 		dev_err(dev, "cannot allocate memory\n");
1177 		goto out;
1178 	}
1179 
1180 	sinfo = info->par;
1181 	sinfo->pdev = pdev;
1182 	sinfo->info = info;
1183 
1184 	INIT_LIST_HEAD(&info->modelist);
1185 
1186 	if (pdev->dev.of_node) {
1187 		ret = atmel_lcdfb_of_init(sinfo);
1188 		if (ret)
1189 			goto free_info;
1190 	} else if (dev_get_platdata(dev)) {
1191 		struct fb_monspecs *monspecs;
1192 		int i;
1193 
1194 		pdata = dev_get_platdata(dev);
1195 		monspecs = pdata->default_monspecs;
1196 		sinfo->pdata = *pdata;
1197 
1198 		for (i = 0; i < monspecs->modedb_len; i++)
1199 			fb_add_videomode(&monspecs->modedb[i], &info->modelist);
1200 
1201 		sinfo->config = atmel_lcdfb_get_config(pdev);
1202 
1203 		info->var.bits_per_pixel = pdata->default_bpp ? pdata->default_bpp : 16;
1204 		memcpy(&info->monspecs, pdata->default_monspecs, sizeof(info->monspecs));
1205 	} else {
1206 		dev_err(dev, "cannot get default configuration\n");
1207 		goto free_info;
1208 	}
1209 
1210 	if (!sinfo->config)
1211 		goto free_info;
1212 
1213 	sinfo->reg_lcd = devm_regulator_get(&pdev->dev, "lcd");
1214 	if (IS_ERR(sinfo->reg_lcd))
1215 		sinfo->reg_lcd = NULL;
1216 
1217 	info->flags = ATMEL_LCDFB_FBINFO_DEFAULT;
1218 	info->pseudo_palette = sinfo->pseudo_palette;
1219 	info->fbops = &atmel_lcdfb_ops;
1220 
1221 	info->fix = atmel_lcdfb_fix;
1222 	strcpy(info->fix.id, sinfo->pdev->name);
1223 
1224 	/* Enable LCDC Clocks */
1225 	sinfo->bus_clk = clk_get(dev, "hclk");
1226 	if (IS_ERR(sinfo->bus_clk)) {
1227 		ret = PTR_ERR(sinfo->bus_clk);
1228 		goto free_info;
1229 	}
1230 	sinfo->lcdc_clk = clk_get(dev, "lcdc_clk");
1231 	if (IS_ERR(sinfo->lcdc_clk)) {
1232 		ret = PTR_ERR(sinfo->lcdc_clk);
1233 		goto put_bus_clk;
1234 	}
1235 	atmel_lcdfb_start_clock(sinfo);
1236 
1237 	modelist = list_first_entry(&info->modelist,
1238 			struct fb_modelist, list);
1239 	fb_videomode_to_var(&info->var, &modelist->mode);
1240 
1241 	atmel_lcdfb_check_var(&info->var, info);
1242 
1243 	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1244 	if (!regs) {
1245 		dev_err(dev, "resources unusable\n");
1246 		ret = -ENXIO;
1247 		goto stop_clk;
1248 	}
1249 
1250 	sinfo->irq_base = platform_get_irq(pdev, 0);
1251 	if (sinfo->irq_base < 0) {
1252 		dev_err(dev, "unable to get irq\n");
1253 		ret = sinfo->irq_base;
1254 		goto stop_clk;
1255 	}
1256 
1257 	/* Initialize video memory */
1258 	map = platform_get_resource(pdev, IORESOURCE_MEM, 1);
1259 	if (map) {
1260 		/* use a pre-allocated memory buffer */
1261 		info->fix.smem_start = map->start;
1262 		info->fix.smem_len = resource_size(map);
1263 		if (!request_mem_region(info->fix.smem_start,
1264 					info->fix.smem_len, pdev->name)) {
1265 			ret = -EBUSY;
1266 			goto stop_clk;
1267 		}
1268 
1269 		info->screen_base = ioremap(info->fix.smem_start, info->fix.smem_len);
1270 		if (!info->screen_base) {
1271 			ret = -ENOMEM;
1272 			goto release_intmem;
1273 		}
1274 
1275 		/*
1276 		 * Don't clear the framebuffer -- someone may have set
1277 		 * up a splash image.
1278 		 */
1279 	} else {
1280 		/* allocate memory buffer */
1281 		ret = atmel_lcdfb_alloc_video_memory(sinfo);
1282 		if (ret < 0) {
1283 			dev_err(dev, "cannot allocate framebuffer: %d\n", ret);
1284 			goto stop_clk;
1285 		}
1286 	}
1287 
1288 	/* LCDC registers */
1289 	info->fix.mmio_start = regs->start;
1290 	info->fix.mmio_len = resource_size(regs);
1291 
1292 	if (!request_mem_region(info->fix.mmio_start,
1293 				info->fix.mmio_len, pdev->name)) {
1294 		ret = -EBUSY;
1295 		goto free_fb;
1296 	}
1297 
1298 	sinfo->mmio = ioremap(info->fix.mmio_start, info->fix.mmio_len);
1299 	if (!sinfo->mmio) {
1300 		dev_err(dev, "cannot map LCDC registers\n");
1301 		ret = -ENOMEM;
1302 		goto release_mem;
1303 	}
1304 
1305 	/* Initialize PWM for contrast or backlight ("off") */
1306 	init_contrast(sinfo);
1307 
1308 	/* interrupt */
1309 	ret = request_irq(sinfo->irq_base, atmel_lcdfb_interrupt, 0, pdev->name, info);
1310 	if (ret) {
1311 		dev_err(dev, "request_irq failed: %d\n", ret);
1312 		goto unmap_mmio;
1313 	}
1314 
1315 	/* Some operations on the LCDC might sleep and
1316 	 * require a preemptible task context */
1317 	INIT_WORK(&sinfo->task, atmel_lcdfb_task);
1318 
1319 	ret = atmel_lcdfb_init_fbinfo(sinfo);
1320 	if (ret < 0) {
1321 		dev_err(dev, "init fbinfo failed: %d\n", ret);
1322 		goto unregister_irqs;
1323 	}
1324 
1325 	ret = atmel_lcdfb_set_par(info);
1326 	if (ret < 0) {
1327 		dev_err(dev, "set par failed: %d\n", ret);
1328 		goto unregister_irqs;
1329 	}
1330 
1331 	dev_set_drvdata(dev, info);
1332 
1333 	/*
1334 	 * Tell the world that we're ready to go
1335 	 */
1336 	ret = register_framebuffer(info);
1337 	if (ret < 0) {
1338 		dev_err(dev, "failed to register framebuffer device: %d\n", ret);
1339 		goto reset_drvdata;
1340 	}
1341 
1342 	/* Power up the LCDC screen */
1343 	atmel_lcdfb_power_control(sinfo, 1);
1344 
1345 	dev_info(dev, "fb%d: Atmel LCDC at 0x%08lx (mapped at %p), irq %d\n",
1346 		       info->node, info->fix.mmio_start, sinfo->mmio, sinfo->irq_base);
1347 
1348 	return 0;
1349 
1350 reset_drvdata:
1351 	dev_set_drvdata(dev, NULL);
1352 	fb_dealloc_cmap(&info->cmap);
1353 unregister_irqs:
1354 	cancel_work_sync(&sinfo->task);
1355 	free_irq(sinfo->irq_base, info);
1356 unmap_mmio:
1357 	exit_backlight(sinfo);
1358 	iounmap(sinfo->mmio);
1359 release_mem:
1360  	release_mem_region(info->fix.mmio_start, info->fix.mmio_len);
1361 free_fb:
1362 	if (map)
1363 		iounmap(info->screen_base);
1364 	else
1365 		atmel_lcdfb_free_video_memory(sinfo);
1366 
1367 release_intmem:
1368 	if (map)
1369 		release_mem_region(info->fix.smem_start, info->fix.smem_len);
1370 stop_clk:
1371 	atmel_lcdfb_stop_clock(sinfo);
1372 	clk_put(sinfo->lcdc_clk);
1373 put_bus_clk:
1374 	clk_put(sinfo->bus_clk);
1375 free_info:
1376 	framebuffer_release(info);
1377 out:
1378 	dev_dbg(dev, "%s FAILED\n", __func__);
1379 	return ret;
1380 }
1381 
1382 static int __exit atmel_lcdfb_remove(struct platform_device *pdev)
1383 {
1384 	struct device *dev = &pdev->dev;
1385 	struct fb_info *info = dev_get_drvdata(dev);
1386 	struct atmel_lcdfb_info *sinfo;
1387 	struct atmel_lcdfb_pdata *pdata;
1388 
1389 	if (!info || !info->par)
1390 		return 0;
1391 	sinfo = info->par;
1392 	pdata = &sinfo->pdata;
1393 
1394 	cancel_work_sync(&sinfo->task);
1395 	exit_backlight(sinfo);
1396 	atmel_lcdfb_power_control(sinfo, 0);
1397 	unregister_framebuffer(info);
1398 	atmel_lcdfb_stop_clock(sinfo);
1399 	clk_put(sinfo->lcdc_clk);
1400 	clk_put(sinfo->bus_clk);
1401 	fb_dealloc_cmap(&info->cmap);
1402 	free_irq(sinfo->irq_base, info);
1403 	iounmap(sinfo->mmio);
1404  	release_mem_region(info->fix.mmio_start, info->fix.mmio_len);
1405 	if (platform_get_resource(pdev, IORESOURCE_MEM, 1)) {
1406 		iounmap(info->screen_base);
1407 		release_mem_region(info->fix.smem_start, info->fix.smem_len);
1408 	} else {
1409 		atmel_lcdfb_free_video_memory(sinfo);
1410 	}
1411 
1412 	framebuffer_release(info);
1413 
1414 	return 0;
1415 }
1416 
1417 #ifdef CONFIG_PM
1418 
1419 static int atmel_lcdfb_suspend(struct platform_device *pdev, pm_message_t mesg)
1420 {
1421 	struct fb_info *info = platform_get_drvdata(pdev);
1422 	struct atmel_lcdfb_info *sinfo = info->par;
1423 
1424 	/*
1425 	 * We don't want to handle interrupts while the clock is
1426 	 * stopped. It may take forever.
1427 	 */
1428 	lcdc_writel(sinfo, ATMEL_LCDC_IDR, ~0UL);
1429 
1430 	sinfo->saved_lcdcon = lcdc_readl(sinfo, ATMEL_LCDC_CONTRAST_CTR);
1431 	lcdc_writel(sinfo, ATMEL_LCDC_CONTRAST_CTR, 0);
1432 	atmel_lcdfb_power_control(sinfo, 0);
1433 	atmel_lcdfb_stop(sinfo);
1434 	atmel_lcdfb_stop_clock(sinfo);
1435 
1436 	return 0;
1437 }
1438 
1439 static int atmel_lcdfb_resume(struct platform_device *pdev)
1440 {
1441 	struct fb_info *info = platform_get_drvdata(pdev);
1442 	struct atmel_lcdfb_info *sinfo = info->par;
1443 
1444 	atmel_lcdfb_start_clock(sinfo);
1445 	atmel_lcdfb_start(sinfo);
1446 	atmel_lcdfb_power_control(sinfo, 1);
1447 	lcdc_writel(sinfo, ATMEL_LCDC_CONTRAST_CTR, sinfo->saved_lcdcon);
1448 
1449 	/* Enable FIFO & DMA errors */
1450 	lcdc_writel(sinfo, ATMEL_LCDC_IER, ATMEL_LCDC_UFLWI
1451 			| ATMEL_LCDC_OWRI | ATMEL_LCDC_MERI);
1452 
1453 	return 0;
1454 }
1455 
1456 #else
1457 #define atmel_lcdfb_suspend	NULL
1458 #define atmel_lcdfb_resume	NULL
1459 #endif
1460 
1461 static struct platform_driver atmel_lcdfb_driver = {
1462 	.remove		= __exit_p(atmel_lcdfb_remove),
1463 	.suspend	= atmel_lcdfb_suspend,
1464 	.resume		= atmel_lcdfb_resume,
1465 	.id_table	= atmel_lcdfb_devtypes,
1466 	.driver		= {
1467 		.name	= "atmel_lcdfb",
1468 		.of_match_table	= of_match_ptr(atmel_lcdfb_dt_ids),
1469 	},
1470 };
1471 
1472 module_platform_driver_probe(atmel_lcdfb_driver, atmel_lcdfb_probe);
1473 
1474 MODULE_DESCRIPTION("AT91/AT32 LCD Controller framebuffer driver");
1475 MODULE_AUTHOR("Nicolas Ferre <nicolas.ferre@atmel.com>");
1476 MODULE_LICENSE("GPL");
1477