xref: /openbmc/linux/drivers/gpu/drm/stm/ltdc.c (revision 85dc2c65)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) STMicroelectronics SA 2017
4  *
5  * Authors: Philippe Cornu <philippe.cornu@st.com>
6  *          Yannick Fertre <yannick.fertre@st.com>
7  *          Fabien Dessenne <fabien.dessenne@st.com>
8  *          Mickael Reulier <mickael.reulier@st.com>
9  */
10 
11 #include <linux/clk.h>
12 #include <linux/component.h>
13 #include <linux/of_address.h>
14 #include <linux/of_graph.h>
15 #include <linux/reset.h>
16 
17 #include <drm/drm_atomic.h>
18 #include <drm/drm_atomic_helper.h>
19 #include <drm/drm_crtc_helper.h>
20 #include <drm/drm_fb_cma_helper.h>
21 #include <drm/drm_gem_cma_helper.h>
22 #include <drm/drm_of.h>
23 #include <drm/drm_bridge.h>
24 #include <drm/drm_plane_helper.h>
25 
26 #include <video/videomode.h>
27 
28 #include "ltdc.h"
29 
30 #define NB_CRTC 1
31 #define CRTC_MASK GENMASK(NB_CRTC - 1, 0)
32 
33 #define MAX_IRQ 4
34 
35 #define MAX_ENDPOINTS 2
36 
37 #define HWVER_10200 0x010200
38 #define HWVER_10300 0x010300
39 #define HWVER_20101 0x020101
40 
41 /*
42  * The address of some registers depends on the HW version: such registers have
43  * an extra offset specified with reg_ofs.
44  */
45 #define REG_OFS_NONE	0
46 #define REG_OFS_4	4		/* Insertion of "Layer Conf. 2" reg */
47 #define REG_OFS		(ldev->caps.reg_ofs)
48 #define LAY_OFS		0x80		/* Register Offset between 2 layers */
49 
50 /* Global register offsets */
51 #define LTDC_IDR	0x0000		/* IDentification */
52 #define LTDC_LCR	0x0004		/* Layer Count */
53 #define LTDC_SSCR	0x0008		/* Synchronization Size Configuration */
54 #define LTDC_BPCR	0x000C		/* Back Porch Configuration */
55 #define LTDC_AWCR	0x0010		/* Active Width Configuration */
56 #define LTDC_TWCR	0x0014		/* Total Width Configuration */
57 #define LTDC_GCR	0x0018		/* Global Control */
58 #define LTDC_GC1R	0x001C		/* Global Configuration 1 */
59 #define LTDC_GC2R	0x0020		/* Global Configuration 2 */
60 #define LTDC_SRCR	0x0024		/* Shadow Reload Configuration */
61 #define LTDC_GACR	0x0028		/* GAmma Correction */
62 #define LTDC_BCCR	0x002C		/* Background Color Configuration */
63 #define LTDC_IER	0x0034		/* Interrupt Enable */
64 #define LTDC_ISR	0x0038		/* Interrupt Status */
65 #define LTDC_ICR	0x003C		/* Interrupt Clear */
66 #define LTDC_LIPCR	0x0040		/* Line Interrupt Position Conf. */
67 #define LTDC_CPSR	0x0044		/* Current Position Status */
68 #define LTDC_CDSR	0x0048		/* Current Display Status */
69 
70 /* Layer register offsets */
71 #define LTDC_L1LC1R	(0x80)		/* L1 Layer Configuration 1 */
72 #define LTDC_L1LC2R	(0x84)		/* L1 Layer Configuration 2 */
73 #define LTDC_L1CR	(0x84 + REG_OFS)/* L1 Control */
74 #define LTDC_L1WHPCR	(0x88 + REG_OFS)/* L1 Window Hor Position Config */
75 #define LTDC_L1WVPCR	(0x8C + REG_OFS)/* L1 Window Vert Position Config */
76 #define LTDC_L1CKCR	(0x90 + REG_OFS)/* L1 Color Keying Configuration */
77 #define LTDC_L1PFCR	(0x94 + REG_OFS)/* L1 Pixel Format Configuration */
78 #define LTDC_L1CACR	(0x98 + REG_OFS)/* L1 Constant Alpha Config */
79 #define LTDC_L1DCCR	(0x9C + REG_OFS)/* L1 Default Color Configuration */
80 #define LTDC_L1BFCR	(0xA0 + REG_OFS)/* L1 Blend Factors Configuration */
81 #define LTDC_L1FBBCR	(0xA4 + REG_OFS)/* L1 FrameBuffer Bus Control */
82 #define LTDC_L1AFBCR	(0xA8 + REG_OFS)/* L1 AuxFB Control */
83 #define LTDC_L1CFBAR	(0xAC + REG_OFS)/* L1 Color FrameBuffer Address */
84 #define LTDC_L1CFBLR	(0xB0 + REG_OFS)/* L1 Color FrameBuffer Length */
85 #define LTDC_L1CFBLNR	(0xB4 + REG_OFS)/* L1 Color FrameBuffer Line Nb */
86 #define LTDC_L1AFBAR	(0xB8 + REG_OFS)/* L1 AuxFB Address */
87 #define LTDC_L1AFBLR	(0xBC + REG_OFS)/* L1 AuxFB Length */
88 #define LTDC_L1AFBLNR	(0xC0 + REG_OFS)/* L1 AuxFB Line Number */
89 #define LTDC_L1CLUTWR	(0xC4 + REG_OFS)/* L1 CLUT Write */
90 #define LTDC_L1YS1R	(0xE0 + REG_OFS)/* L1 YCbCr Scale 1 */
91 #define LTDC_L1YS2R	(0xE4 + REG_OFS)/* L1 YCbCr Scale 2 */
92 
93 /* Bit definitions */
94 #define SSCR_VSH	GENMASK(10, 0)	/* Vertical Synchronization Height */
95 #define SSCR_HSW	GENMASK(27, 16)	/* Horizontal Synchronization Width */
96 
97 #define BPCR_AVBP	GENMASK(10, 0)	/* Accumulated Vertical Back Porch */
98 #define BPCR_AHBP	GENMASK(27, 16)	/* Accumulated Horizontal Back Porch */
99 
100 #define AWCR_AAH	GENMASK(10, 0)	/* Accumulated Active Height */
101 #define AWCR_AAW	GENMASK(27, 16)	/* Accumulated Active Width */
102 
103 #define TWCR_TOTALH	GENMASK(10, 0)	/* TOTAL Height */
104 #define TWCR_TOTALW	GENMASK(27, 16)	/* TOTAL Width */
105 
106 #define GCR_LTDCEN	BIT(0)		/* LTDC ENable */
107 #define GCR_DEN		BIT(16)		/* Dither ENable */
108 #define GCR_PCPOL	BIT(28)		/* Pixel Clock POLarity-Inverted */
109 #define GCR_DEPOL	BIT(29)		/* Data Enable POLarity-High */
110 #define GCR_VSPOL	BIT(30)		/* Vertical Synchro POLarity-High */
111 #define GCR_HSPOL	BIT(31)		/* Horizontal Synchro POLarity-High */
112 
113 #define GC1R_WBCH	GENMASK(3, 0)	/* Width of Blue CHannel output */
114 #define GC1R_WGCH	GENMASK(7, 4)	/* Width of Green Channel output */
115 #define GC1R_WRCH	GENMASK(11, 8)	/* Width of Red Channel output */
116 #define GC1R_PBEN	BIT(12)		/* Precise Blending ENable */
117 #define GC1R_DT		GENMASK(15, 14)	/* Dithering Technique */
118 #define GC1R_GCT	GENMASK(19, 17)	/* Gamma Correction Technique */
119 #define GC1R_SHREN	BIT(21)		/* SHadow Registers ENabled */
120 #define GC1R_BCP	BIT(22)		/* Background Colour Programmable */
121 #define GC1R_BBEN	BIT(23)		/* Background Blending ENabled */
122 #define GC1R_LNIP	BIT(24)		/* Line Number IRQ Position */
123 #define GC1R_TP		BIT(25)		/* Timing Programmable */
124 #define GC1R_IPP	BIT(26)		/* IRQ Polarity Programmable */
125 #define GC1R_SPP	BIT(27)		/* Sync Polarity Programmable */
126 #define GC1R_DWP	BIT(28)		/* Dither Width Programmable */
127 #define GC1R_STREN	BIT(29)		/* STatus Registers ENabled */
128 #define GC1R_BMEN	BIT(31)		/* Blind Mode ENabled */
129 
130 #define GC2R_EDCA	BIT(0)		/* External Display Control Ability  */
131 #define GC2R_STSAEN	BIT(1)		/* Slave Timing Sync Ability ENabled */
132 #define GC2R_DVAEN	BIT(2)		/* Dual-View Ability ENabled */
133 #define GC2R_DPAEN	BIT(3)		/* Dual-Port Ability ENabled */
134 #define GC2R_BW		GENMASK(6, 4)	/* Bus Width (log2 of nb of bytes) */
135 #define GC2R_EDCEN	BIT(7)		/* External Display Control ENabled */
136 
137 #define SRCR_IMR	BIT(0)		/* IMmediate Reload */
138 #define SRCR_VBR	BIT(1)		/* Vertical Blanking Reload */
139 
140 #define BCCR_BCBLACK	0x00		/* Background Color BLACK */
141 #define BCCR_BCBLUE	GENMASK(7, 0)	/* Background Color BLUE */
142 #define BCCR_BCGREEN	GENMASK(15, 8)	/* Background Color GREEN */
143 #define BCCR_BCRED	GENMASK(23, 16)	/* Background Color RED */
144 #define BCCR_BCWHITE	GENMASK(23, 0)	/* Background Color WHITE */
145 
146 #define IER_LIE		BIT(0)		/* Line Interrupt Enable */
147 #define IER_FUIE	BIT(1)		/* Fifo Underrun Interrupt Enable */
148 #define IER_TERRIE	BIT(2)		/* Transfer ERRor Interrupt Enable */
149 #define IER_RRIE	BIT(3)		/* Register Reload Interrupt enable */
150 
151 #define ISR_LIF		BIT(0)		/* Line Interrupt Flag */
152 #define ISR_FUIF	BIT(1)		/* Fifo Underrun Interrupt Flag */
153 #define ISR_TERRIF	BIT(2)		/* Transfer ERRor Interrupt Flag */
154 #define ISR_RRIF	BIT(3)		/* Register Reload Interrupt Flag */
155 
156 #define LXCR_LEN	BIT(0)		/* Layer ENable */
157 #define LXCR_COLKEN	BIT(1)		/* Color Keying Enable */
158 #define LXCR_CLUTEN	BIT(4)		/* Color Look-Up Table ENable */
159 
160 #define LXWHPCR_WHSTPOS	GENMASK(11, 0)	/* Window Horizontal StarT POSition */
161 #define LXWHPCR_WHSPPOS	GENMASK(27, 16)	/* Window Horizontal StoP POSition */
162 
163 #define LXWVPCR_WVSTPOS	GENMASK(10, 0)	/* Window Vertical StarT POSition */
164 #define LXWVPCR_WVSPPOS	GENMASK(26, 16)	/* Window Vertical StoP POSition */
165 
166 #define LXPFCR_PF	GENMASK(2, 0)	/* Pixel Format */
167 
168 #define LXCACR_CONSTA	GENMASK(7, 0)	/* CONSTant Alpha */
169 
170 #define LXBFCR_BF2	GENMASK(2, 0)	/* Blending Factor 2 */
171 #define LXBFCR_BF1	GENMASK(10, 8)	/* Blending Factor 1 */
172 
173 #define LXCFBLR_CFBLL	GENMASK(12, 0)	/* Color Frame Buffer Line Length */
174 #define LXCFBLR_CFBP	GENMASK(28, 16)	/* Color Frame Buffer Pitch in bytes */
175 
176 #define LXCFBLNR_CFBLN	GENMASK(10, 0)	/* Color Frame Buffer Line Number */
177 
178 #define CLUT_SIZE	256
179 
180 #define CONSTA_MAX	0xFF		/* CONSTant Alpha MAX= 1.0 */
181 #define BF1_PAXCA	0x600		/* Pixel Alpha x Constant Alpha */
182 #define BF1_CA		0x400		/* Constant Alpha */
183 #define BF2_1PAXCA	0x007		/* 1 - (Pixel Alpha x Constant Alpha) */
184 #define BF2_1CA		0x005		/* 1 - Constant Alpha */
185 
186 #define NB_PF		8		/* Max nb of HW pixel format */
187 
188 enum ltdc_pix_fmt {
189 	PF_NONE,
190 	/* RGB formats */
191 	PF_ARGB8888,		/* ARGB [32 bits] */
192 	PF_RGBA8888,		/* RGBA [32 bits] */
193 	PF_RGB888,		/* RGB [24 bits] */
194 	PF_RGB565,		/* RGB [16 bits] */
195 	PF_ARGB1555,		/* ARGB A:1 bit RGB:15 bits [16 bits] */
196 	PF_ARGB4444,		/* ARGB A:4 bits R/G/B: 4 bits each [16 bits] */
197 	/* Indexed formats */
198 	PF_L8,			/* Indexed 8 bits [8 bits] */
199 	PF_AL44,		/* Alpha:4 bits + indexed 4 bits [8 bits] */
200 	PF_AL88			/* Alpha:8 bits + indexed 8 bits [16 bits] */
201 };
202 
203 /* The index gives the encoding of the pixel format for an HW version */
204 static const enum ltdc_pix_fmt ltdc_pix_fmt_a0[NB_PF] = {
205 	PF_ARGB8888,		/* 0x00 */
206 	PF_RGB888,		/* 0x01 */
207 	PF_RGB565,		/* 0x02 */
208 	PF_ARGB1555,		/* 0x03 */
209 	PF_ARGB4444,		/* 0x04 */
210 	PF_L8,			/* 0x05 */
211 	PF_AL44,		/* 0x06 */
212 	PF_AL88			/* 0x07 */
213 };
214 
215 static const enum ltdc_pix_fmt ltdc_pix_fmt_a1[NB_PF] = {
216 	PF_ARGB8888,		/* 0x00 */
217 	PF_RGB888,		/* 0x01 */
218 	PF_RGB565,		/* 0x02 */
219 	PF_RGBA8888,		/* 0x03 */
220 	PF_AL44,		/* 0x04 */
221 	PF_L8,			/* 0x05 */
222 	PF_ARGB1555,		/* 0x06 */
223 	PF_ARGB4444		/* 0x07 */
224 };
225 
226 static inline u32 reg_read(void __iomem *base, u32 reg)
227 {
228 	return readl_relaxed(base + reg);
229 }
230 
231 static inline void reg_write(void __iomem *base, u32 reg, u32 val)
232 {
233 	writel_relaxed(val, base + reg);
234 }
235 
236 static inline void reg_set(void __iomem *base, u32 reg, u32 mask)
237 {
238 	reg_write(base, reg, reg_read(base, reg) | mask);
239 }
240 
241 static inline void reg_clear(void __iomem *base, u32 reg, u32 mask)
242 {
243 	reg_write(base, reg, reg_read(base, reg) & ~mask);
244 }
245 
246 static inline void reg_update_bits(void __iomem *base, u32 reg, u32 mask,
247 				   u32 val)
248 {
249 	reg_write(base, reg, (reg_read(base, reg) & ~mask) | val);
250 }
251 
252 static inline struct ltdc_device *crtc_to_ltdc(struct drm_crtc *crtc)
253 {
254 	return (struct ltdc_device *)crtc->dev->dev_private;
255 }
256 
257 static inline struct ltdc_device *plane_to_ltdc(struct drm_plane *plane)
258 {
259 	return (struct ltdc_device *)plane->dev->dev_private;
260 }
261 
262 static inline struct ltdc_device *encoder_to_ltdc(struct drm_encoder *enc)
263 {
264 	return (struct ltdc_device *)enc->dev->dev_private;
265 }
266 
267 static inline enum ltdc_pix_fmt to_ltdc_pixelformat(u32 drm_fmt)
268 {
269 	enum ltdc_pix_fmt pf;
270 
271 	switch (drm_fmt) {
272 	case DRM_FORMAT_ARGB8888:
273 	case DRM_FORMAT_XRGB8888:
274 		pf = PF_ARGB8888;
275 		break;
276 	case DRM_FORMAT_RGBA8888:
277 	case DRM_FORMAT_RGBX8888:
278 		pf = PF_RGBA8888;
279 		break;
280 	case DRM_FORMAT_RGB888:
281 		pf = PF_RGB888;
282 		break;
283 	case DRM_FORMAT_RGB565:
284 		pf = PF_RGB565;
285 		break;
286 	case DRM_FORMAT_ARGB1555:
287 	case DRM_FORMAT_XRGB1555:
288 		pf = PF_ARGB1555;
289 		break;
290 	case DRM_FORMAT_ARGB4444:
291 	case DRM_FORMAT_XRGB4444:
292 		pf = PF_ARGB4444;
293 		break;
294 	case DRM_FORMAT_C8:
295 		pf = PF_L8;
296 		break;
297 	default:
298 		pf = PF_NONE;
299 		break;
300 		/* Note: There are no DRM_FORMAT for AL44 and AL88 */
301 	}
302 
303 	return pf;
304 }
305 
306 static inline u32 to_drm_pixelformat(enum ltdc_pix_fmt pf)
307 {
308 	switch (pf) {
309 	case PF_ARGB8888:
310 		return DRM_FORMAT_ARGB8888;
311 	case PF_RGBA8888:
312 		return DRM_FORMAT_RGBA8888;
313 	case PF_RGB888:
314 		return DRM_FORMAT_RGB888;
315 	case PF_RGB565:
316 		return DRM_FORMAT_RGB565;
317 	case PF_ARGB1555:
318 		return DRM_FORMAT_ARGB1555;
319 	case PF_ARGB4444:
320 		return DRM_FORMAT_ARGB4444;
321 	case PF_L8:
322 		return DRM_FORMAT_C8;
323 	case PF_AL44:		/* No DRM support */
324 	case PF_AL88:		/* No DRM support */
325 	case PF_NONE:
326 	default:
327 		return 0;
328 	}
329 }
330 
331 static inline u32 get_pixelformat_without_alpha(u32 drm)
332 {
333 	switch (drm) {
334 	case DRM_FORMAT_ARGB4444:
335 		return DRM_FORMAT_XRGB4444;
336 	case DRM_FORMAT_RGBA4444:
337 		return DRM_FORMAT_RGBX4444;
338 	case DRM_FORMAT_ARGB1555:
339 		return DRM_FORMAT_XRGB1555;
340 	case DRM_FORMAT_RGBA5551:
341 		return DRM_FORMAT_RGBX5551;
342 	case DRM_FORMAT_ARGB8888:
343 		return DRM_FORMAT_XRGB8888;
344 	case DRM_FORMAT_RGBA8888:
345 		return DRM_FORMAT_RGBX8888;
346 	default:
347 		return 0;
348 	}
349 }
350 
351 static irqreturn_t ltdc_irq_thread(int irq, void *arg)
352 {
353 	struct drm_device *ddev = arg;
354 	struct ltdc_device *ldev = ddev->dev_private;
355 	struct drm_crtc *crtc = drm_crtc_from_index(ddev, 0);
356 
357 	/* Line IRQ : trigger the vblank event */
358 	if (ldev->irq_status & ISR_LIF)
359 		drm_crtc_handle_vblank(crtc);
360 
361 	/* Save FIFO Underrun & Transfer Error status */
362 	mutex_lock(&ldev->err_lock);
363 	if (ldev->irq_status & ISR_FUIF)
364 		ldev->error_status |= ISR_FUIF;
365 	if (ldev->irq_status & ISR_TERRIF)
366 		ldev->error_status |= ISR_TERRIF;
367 	mutex_unlock(&ldev->err_lock);
368 
369 	return IRQ_HANDLED;
370 }
371 
372 static irqreturn_t ltdc_irq(int irq, void *arg)
373 {
374 	struct drm_device *ddev = arg;
375 	struct ltdc_device *ldev = ddev->dev_private;
376 
377 	/* Read & Clear the interrupt status */
378 	ldev->irq_status = reg_read(ldev->regs, LTDC_ISR);
379 	reg_write(ldev->regs, LTDC_ICR, ldev->irq_status);
380 
381 	return IRQ_WAKE_THREAD;
382 }
383 
384 /*
385  * DRM_CRTC
386  */
387 
388 static void ltdc_crtc_update_clut(struct drm_crtc *crtc)
389 {
390 	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
391 	struct drm_color_lut *lut;
392 	u32 val;
393 	int i;
394 
395 	if (!crtc->state->color_mgmt_changed || !crtc->state->gamma_lut)
396 		return;
397 
398 	lut = (struct drm_color_lut *)crtc->state->gamma_lut->data;
399 
400 	for (i = 0; i < CLUT_SIZE; i++, lut++) {
401 		val = ((lut->red << 8) & 0xff0000) | (lut->green & 0xff00) |
402 			(lut->blue >> 8) | (i << 24);
403 		reg_write(ldev->regs, LTDC_L1CLUTWR, val);
404 	}
405 }
406 
407 static void ltdc_crtc_atomic_enable(struct drm_crtc *crtc,
408 				    struct drm_crtc_state *old_state)
409 {
410 	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
411 
412 	DRM_DEBUG_DRIVER("\n");
413 
414 	/* Sets the background color value */
415 	reg_write(ldev->regs, LTDC_BCCR, BCCR_BCBLACK);
416 
417 	/* Enable IRQ */
418 	reg_set(ldev->regs, LTDC_IER, IER_RRIE | IER_FUIE | IER_TERRIE);
419 
420 	/* Immediately commit the planes */
421 	reg_set(ldev->regs, LTDC_SRCR, SRCR_IMR);
422 
423 	/* Enable LTDC */
424 	reg_set(ldev->regs, LTDC_GCR, GCR_LTDCEN);
425 
426 	drm_crtc_vblank_on(crtc);
427 }
428 
429 static void ltdc_crtc_atomic_disable(struct drm_crtc *crtc,
430 				     struct drm_crtc_state *old_state)
431 {
432 	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
433 
434 	DRM_DEBUG_DRIVER("\n");
435 
436 	drm_crtc_vblank_off(crtc);
437 
438 	/* disable LTDC */
439 	reg_clear(ldev->regs, LTDC_GCR, GCR_LTDCEN);
440 
441 	/* disable IRQ */
442 	reg_clear(ldev->regs, LTDC_IER, IER_RRIE | IER_FUIE | IER_TERRIE);
443 
444 	/* immediately commit disable of layers before switching off LTDC */
445 	reg_set(ldev->regs, LTDC_SRCR, SRCR_IMR);
446 }
447 
448 #define CLK_TOLERANCE_HZ 50
449 
450 static enum drm_mode_status
451 ltdc_crtc_mode_valid(struct drm_crtc *crtc,
452 		     const struct drm_display_mode *mode)
453 {
454 	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
455 	int target = mode->clock * 1000;
456 	int target_min = target - CLK_TOLERANCE_HZ;
457 	int target_max = target + CLK_TOLERANCE_HZ;
458 	int result;
459 
460 	result = clk_round_rate(ldev->pixel_clk, target);
461 
462 	DRM_DEBUG_DRIVER("clk rate target %d, available %d\n", target, result);
463 
464 	/* Filter modes according to the max frequency supported by the pads */
465 	if (result > ldev->caps.pad_max_freq_hz)
466 		return MODE_CLOCK_HIGH;
467 
468 	/*
469 	 * Accept all "preferred" modes:
470 	 * - this is important for panels because panel clock tolerances are
471 	 *   bigger than hdmi ones and there is no reason to not accept them
472 	 *   (the fps may vary a little but it is not a problem).
473 	 * - the hdmi preferred mode will be accepted too, but userland will
474 	 *   be able to use others hdmi "valid" modes if necessary.
475 	 */
476 	if (mode->type & DRM_MODE_TYPE_PREFERRED)
477 		return MODE_OK;
478 
479 	/*
480 	 * Filter modes according to the clock value, particularly useful for
481 	 * hdmi modes that require precise pixel clocks.
482 	 */
483 	if (result < target_min || result > target_max)
484 		return MODE_CLOCK_RANGE;
485 
486 	return MODE_OK;
487 }
488 
489 static bool ltdc_crtc_mode_fixup(struct drm_crtc *crtc,
490 				 const struct drm_display_mode *mode,
491 				 struct drm_display_mode *adjusted_mode)
492 {
493 	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
494 	int rate = mode->clock * 1000;
495 
496 	/*
497 	 * TODO clk_round_rate() does not work yet. When ready, it can
498 	 * be used instead of clk_set_rate() then clk_get_rate().
499 	 */
500 
501 	clk_disable(ldev->pixel_clk);
502 	if (clk_set_rate(ldev->pixel_clk, rate) < 0) {
503 		DRM_ERROR("Cannot set rate (%dHz) for pixel clk\n", rate);
504 		return false;
505 	}
506 	clk_enable(ldev->pixel_clk);
507 
508 	adjusted_mode->clock = clk_get_rate(ldev->pixel_clk) / 1000;
509 
510 	return true;
511 }
512 
513 static void ltdc_crtc_mode_set_nofb(struct drm_crtc *crtc)
514 {
515 	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
516 	struct drm_display_mode *mode = &crtc->state->adjusted_mode;
517 	struct videomode vm;
518 	u32 hsync, vsync, accum_hbp, accum_vbp, accum_act_w, accum_act_h;
519 	u32 total_width, total_height;
520 	u32 val;
521 
522 	drm_display_mode_to_videomode(mode, &vm);
523 
524 	DRM_DEBUG_DRIVER("CRTC:%d mode:%s\n", crtc->base.id, mode->name);
525 	DRM_DEBUG_DRIVER("Video mode: %dx%d", vm.hactive, vm.vactive);
526 	DRM_DEBUG_DRIVER(" hfp %d hbp %d hsl %d vfp %d vbp %d vsl %d\n",
527 			 vm.hfront_porch, vm.hback_porch, vm.hsync_len,
528 			 vm.vfront_porch, vm.vback_porch, vm.vsync_len);
529 
530 	/* Convert video timings to ltdc timings */
531 	hsync = vm.hsync_len - 1;
532 	vsync = vm.vsync_len - 1;
533 	accum_hbp = hsync + vm.hback_porch;
534 	accum_vbp = vsync + vm.vback_porch;
535 	accum_act_w = accum_hbp + vm.hactive;
536 	accum_act_h = accum_vbp + vm.vactive;
537 	total_width = accum_act_w + vm.hfront_porch;
538 	total_height = accum_act_h + vm.vfront_porch;
539 
540 	/* Configures the HS, VS, DE and PC polarities. Default Active Low */
541 	val = 0;
542 
543 	if (vm.flags & DISPLAY_FLAGS_HSYNC_HIGH)
544 		val |= GCR_HSPOL;
545 
546 	if (vm.flags & DISPLAY_FLAGS_VSYNC_HIGH)
547 		val |= GCR_VSPOL;
548 
549 	if (vm.flags & DISPLAY_FLAGS_DE_HIGH)
550 		val |= GCR_DEPOL;
551 
552 	if (vm.flags & DISPLAY_FLAGS_PIXDATA_NEGEDGE)
553 		val |= GCR_PCPOL;
554 
555 	reg_update_bits(ldev->regs, LTDC_GCR,
556 			GCR_HSPOL | GCR_VSPOL | GCR_DEPOL | GCR_PCPOL, val);
557 
558 	/* Set Synchronization size */
559 	val = (hsync << 16) | vsync;
560 	reg_update_bits(ldev->regs, LTDC_SSCR, SSCR_VSH | SSCR_HSW, val);
561 
562 	/* Set Accumulated Back porch */
563 	val = (accum_hbp << 16) | accum_vbp;
564 	reg_update_bits(ldev->regs, LTDC_BPCR, BPCR_AVBP | BPCR_AHBP, val);
565 
566 	/* Set Accumulated Active Width */
567 	val = (accum_act_w << 16) | accum_act_h;
568 	reg_update_bits(ldev->regs, LTDC_AWCR, AWCR_AAW | AWCR_AAH, val);
569 
570 	/* Set total width & height */
571 	val = (total_width << 16) | total_height;
572 	reg_update_bits(ldev->regs, LTDC_TWCR, TWCR_TOTALH | TWCR_TOTALW, val);
573 
574 	reg_write(ldev->regs, LTDC_LIPCR, (accum_act_h + 1));
575 }
576 
577 static void ltdc_crtc_atomic_flush(struct drm_crtc *crtc,
578 				   struct drm_crtc_state *old_crtc_state)
579 {
580 	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
581 	struct drm_pending_vblank_event *event = crtc->state->event;
582 
583 	DRM_DEBUG_ATOMIC("\n");
584 
585 	ltdc_crtc_update_clut(crtc);
586 
587 	/* Commit shadow registers = update planes at next vblank */
588 	reg_set(ldev->regs, LTDC_SRCR, SRCR_VBR);
589 
590 	if (event) {
591 		crtc->state->event = NULL;
592 
593 		spin_lock_irq(&crtc->dev->event_lock);
594 		if (drm_crtc_vblank_get(crtc) == 0)
595 			drm_crtc_arm_vblank_event(crtc, event);
596 		else
597 			drm_crtc_send_vblank_event(crtc, event);
598 		spin_unlock_irq(&crtc->dev->event_lock);
599 	}
600 }
601 
602 static const struct drm_crtc_helper_funcs ltdc_crtc_helper_funcs = {
603 	.mode_valid = ltdc_crtc_mode_valid,
604 	.mode_fixup = ltdc_crtc_mode_fixup,
605 	.mode_set_nofb = ltdc_crtc_mode_set_nofb,
606 	.atomic_flush = ltdc_crtc_atomic_flush,
607 	.atomic_enable = ltdc_crtc_atomic_enable,
608 	.atomic_disable = ltdc_crtc_atomic_disable,
609 };
610 
611 static int ltdc_crtc_enable_vblank(struct drm_crtc *crtc)
612 {
613 	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
614 
615 	DRM_DEBUG_DRIVER("\n");
616 	reg_set(ldev->regs, LTDC_IER, IER_LIE);
617 
618 	return 0;
619 }
620 
621 static void ltdc_crtc_disable_vblank(struct drm_crtc *crtc)
622 {
623 	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
624 
625 	DRM_DEBUG_DRIVER("\n");
626 	reg_clear(ldev->regs, LTDC_IER, IER_LIE);
627 }
628 
629 static const struct drm_crtc_funcs ltdc_crtc_funcs = {
630 	.destroy = drm_crtc_cleanup,
631 	.set_config = drm_atomic_helper_set_config,
632 	.page_flip = drm_atomic_helper_page_flip,
633 	.reset = drm_atomic_helper_crtc_reset,
634 	.atomic_duplicate_state = drm_atomic_helper_crtc_duplicate_state,
635 	.atomic_destroy_state = drm_atomic_helper_crtc_destroy_state,
636 	.enable_vblank = ltdc_crtc_enable_vblank,
637 	.disable_vblank = ltdc_crtc_disable_vblank,
638 	.gamma_set = drm_atomic_helper_legacy_gamma_set,
639 };
640 
641 /*
642  * DRM_PLANE
643  */
644 
645 static int ltdc_plane_atomic_check(struct drm_plane *plane,
646 				   struct drm_plane_state *state)
647 {
648 	struct drm_framebuffer *fb = state->fb;
649 	u32 src_x, src_y, src_w, src_h;
650 
651 	DRM_DEBUG_DRIVER("\n");
652 
653 	if (!fb)
654 		return 0;
655 
656 	/* convert src_ from 16:16 format */
657 	src_x = state->src_x >> 16;
658 	src_y = state->src_y >> 16;
659 	src_w = state->src_w >> 16;
660 	src_h = state->src_h >> 16;
661 
662 	/* Reject scaling */
663 	if (src_w != state->crtc_w || src_h != state->crtc_h) {
664 		DRM_ERROR("Scaling is not supported");
665 		return -EINVAL;
666 	}
667 
668 	return 0;
669 }
670 
671 static void ltdc_plane_atomic_update(struct drm_plane *plane,
672 				     struct drm_plane_state *oldstate)
673 {
674 	struct ltdc_device *ldev = plane_to_ltdc(plane);
675 	struct drm_plane_state *state = plane->state;
676 	struct drm_framebuffer *fb = state->fb;
677 	u32 lofs = plane->index * LAY_OFS;
678 	u32 x0 = state->crtc_x;
679 	u32 x1 = state->crtc_x + state->crtc_w - 1;
680 	u32 y0 = state->crtc_y;
681 	u32 y1 = state->crtc_y + state->crtc_h - 1;
682 	u32 src_x, src_y, src_w, src_h;
683 	u32 val, pitch_in_bytes, line_length, paddr, ahbp, avbp, bpcr;
684 	enum ltdc_pix_fmt pf;
685 
686 	if (!state->crtc || !fb) {
687 		DRM_DEBUG_DRIVER("fb or crtc NULL");
688 		return;
689 	}
690 
691 	/* convert src_ from 16:16 format */
692 	src_x = state->src_x >> 16;
693 	src_y = state->src_y >> 16;
694 	src_w = state->src_w >> 16;
695 	src_h = state->src_h >> 16;
696 
697 	DRM_DEBUG_DRIVER("plane:%d fb:%d (%dx%d)@(%d,%d) -> (%dx%d)@(%d,%d)\n",
698 			 plane->base.id, fb->base.id,
699 			 src_w, src_h, src_x, src_y,
700 			 state->crtc_w, state->crtc_h,
701 			 state->crtc_x, state->crtc_y);
702 
703 	bpcr = reg_read(ldev->regs, LTDC_BPCR);
704 	ahbp = (bpcr & BPCR_AHBP) >> 16;
705 	avbp = bpcr & BPCR_AVBP;
706 
707 	/* Configures the horizontal start and stop position */
708 	val = ((x1 + 1 + ahbp) << 16) + (x0 + 1 + ahbp);
709 	reg_update_bits(ldev->regs, LTDC_L1WHPCR + lofs,
710 			LXWHPCR_WHSTPOS | LXWHPCR_WHSPPOS, val);
711 
712 	/* Configures the vertical start and stop position */
713 	val = ((y1 + 1 + avbp) << 16) + (y0 + 1 + avbp);
714 	reg_update_bits(ldev->regs, LTDC_L1WVPCR + lofs,
715 			LXWVPCR_WVSTPOS | LXWVPCR_WVSPPOS, val);
716 
717 	/* Specifies the pixel format */
718 	pf = to_ltdc_pixelformat(fb->format->format);
719 	for (val = 0; val < NB_PF; val++)
720 		if (ldev->caps.pix_fmt_hw[val] == pf)
721 			break;
722 
723 	if (val == NB_PF) {
724 		DRM_ERROR("Pixel format %.4s not supported\n",
725 			  (char *)&fb->format->format);
726 		val = 0;	/* set by default ARGB 32 bits */
727 	}
728 	reg_update_bits(ldev->regs, LTDC_L1PFCR + lofs, LXPFCR_PF, val);
729 
730 	/* Configures the color frame buffer pitch in bytes & line length */
731 	pitch_in_bytes = fb->pitches[0];
732 	line_length = drm_format_plane_cpp(fb->format->format, 0) *
733 		      (x1 - x0 + 1) + (ldev->caps.bus_width >> 3) - 1;
734 	val = ((pitch_in_bytes << 16) | line_length);
735 	reg_update_bits(ldev->regs, LTDC_L1CFBLR + lofs,
736 			LXCFBLR_CFBLL | LXCFBLR_CFBP, val);
737 
738 	/* Specifies the constant alpha value */
739 	val = CONSTA_MAX;
740 	reg_update_bits(ldev->regs, LTDC_L1CACR + lofs, LXCACR_CONSTA, val);
741 
742 	/* Specifies the blending factors */
743 	val = BF1_PAXCA | BF2_1PAXCA;
744 	if (!fb->format->has_alpha)
745 		val = BF1_CA | BF2_1CA;
746 
747 	/* Manage hw-specific capabilities */
748 	if (ldev->caps.non_alpha_only_l1 &&
749 	    plane->type != DRM_PLANE_TYPE_PRIMARY)
750 		val = BF1_PAXCA | BF2_1PAXCA;
751 
752 	reg_update_bits(ldev->regs, LTDC_L1BFCR + lofs,
753 			LXBFCR_BF2 | LXBFCR_BF1, val);
754 
755 	/* Configures the frame buffer line number */
756 	val = y1 - y0 + 1;
757 	reg_update_bits(ldev->regs, LTDC_L1CFBLNR + lofs, LXCFBLNR_CFBLN, val);
758 
759 	/* Sets the FB address */
760 	paddr = (u32)drm_fb_cma_get_gem_addr(fb, state, 0);
761 
762 	DRM_DEBUG_DRIVER("fb: phys 0x%08x", paddr);
763 	reg_write(ldev->regs, LTDC_L1CFBAR + lofs, paddr);
764 
765 	/* Enable layer and CLUT if needed */
766 	val = fb->format->format == DRM_FORMAT_C8 ? LXCR_CLUTEN : 0;
767 	val |= LXCR_LEN;
768 	reg_update_bits(ldev->regs, LTDC_L1CR + lofs,
769 			LXCR_LEN | LXCR_CLUTEN, val);
770 
771 	ldev->plane_fpsi[plane->index].counter++;
772 
773 	mutex_lock(&ldev->err_lock);
774 	if (ldev->error_status & ISR_FUIF) {
775 		DRM_DEBUG_DRIVER("Fifo underrun\n");
776 		ldev->error_status &= ~ISR_FUIF;
777 	}
778 	if (ldev->error_status & ISR_TERRIF) {
779 		DRM_DEBUG_DRIVER("Transfer error\n");
780 		ldev->error_status &= ~ISR_TERRIF;
781 	}
782 	mutex_unlock(&ldev->err_lock);
783 }
784 
785 static void ltdc_plane_atomic_disable(struct drm_plane *plane,
786 				      struct drm_plane_state *oldstate)
787 {
788 	struct ltdc_device *ldev = plane_to_ltdc(plane);
789 	u32 lofs = plane->index * LAY_OFS;
790 
791 	/* disable layer */
792 	reg_clear(ldev->regs, LTDC_L1CR + lofs, LXCR_LEN);
793 
794 	DRM_DEBUG_DRIVER("CRTC:%d plane:%d\n",
795 			 oldstate->crtc->base.id, plane->base.id);
796 }
797 
798 static void ltdc_plane_atomic_print_state(struct drm_printer *p,
799 					  const struct drm_plane_state *state)
800 {
801 	struct drm_plane *plane = state->plane;
802 	struct ltdc_device *ldev = plane_to_ltdc(plane);
803 	struct fps_info *fpsi = &ldev->plane_fpsi[plane->index];
804 	int ms_since_last;
805 	ktime_t now;
806 
807 	now = ktime_get();
808 	ms_since_last = ktime_to_ms(ktime_sub(now, fpsi->last_timestamp));
809 
810 	drm_printf(p, "\tuser_updates=%dfps\n",
811 		   DIV_ROUND_CLOSEST(fpsi->counter * 1000, ms_since_last));
812 
813 	fpsi->last_timestamp = now;
814 	fpsi->counter = 0;
815 }
816 
817 static const struct drm_plane_funcs ltdc_plane_funcs = {
818 	.update_plane = drm_atomic_helper_update_plane,
819 	.disable_plane = drm_atomic_helper_disable_plane,
820 	.destroy = drm_plane_cleanup,
821 	.reset = drm_atomic_helper_plane_reset,
822 	.atomic_duplicate_state = drm_atomic_helper_plane_duplicate_state,
823 	.atomic_destroy_state = drm_atomic_helper_plane_destroy_state,
824 	.atomic_print_state = ltdc_plane_atomic_print_state,
825 };
826 
827 static const struct drm_plane_helper_funcs ltdc_plane_helper_funcs = {
828 	.atomic_check = ltdc_plane_atomic_check,
829 	.atomic_update = ltdc_plane_atomic_update,
830 	.atomic_disable = ltdc_plane_atomic_disable,
831 };
832 
833 static struct drm_plane *ltdc_plane_create(struct drm_device *ddev,
834 					   enum drm_plane_type type)
835 {
836 	unsigned long possible_crtcs = CRTC_MASK;
837 	struct ltdc_device *ldev = ddev->dev_private;
838 	struct device *dev = ddev->dev;
839 	struct drm_plane *plane;
840 	unsigned int i, nb_fmt = 0;
841 	u32 formats[NB_PF * 2];
842 	u32 drm_fmt, drm_fmt_no_alpha;
843 	int ret;
844 
845 	/* Get supported pixel formats */
846 	for (i = 0; i < NB_PF; i++) {
847 		drm_fmt = to_drm_pixelformat(ldev->caps.pix_fmt_hw[i]);
848 		if (!drm_fmt)
849 			continue;
850 		formats[nb_fmt++] = drm_fmt;
851 
852 		/* Add the no-alpha related format if any & supported */
853 		drm_fmt_no_alpha = get_pixelformat_without_alpha(drm_fmt);
854 		if (!drm_fmt_no_alpha)
855 			continue;
856 
857 		/* Manage hw-specific capabilities */
858 		if (ldev->caps.non_alpha_only_l1 &&
859 		    type != DRM_PLANE_TYPE_PRIMARY)
860 			continue;
861 
862 		formats[nb_fmt++] = drm_fmt_no_alpha;
863 	}
864 
865 	plane = devm_kzalloc(dev, sizeof(*plane), GFP_KERNEL);
866 	if (!plane)
867 		return NULL;
868 
869 	ret = drm_universal_plane_init(ddev, plane, possible_crtcs,
870 				       &ltdc_plane_funcs, formats, nb_fmt,
871 				       NULL, type, NULL);
872 	if (ret < 0)
873 		return NULL;
874 
875 	drm_plane_helper_add(plane, &ltdc_plane_helper_funcs);
876 
877 	DRM_DEBUG_DRIVER("plane:%d created\n", plane->base.id);
878 
879 	return plane;
880 }
881 
882 static void ltdc_plane_destroy_all(struct drm_device *ddev)
883 {
884 	struct drm_plane *plane, *plane_temp;
885 
886 	list_for_each_entry_safe(plane, plane_temp,
887 				 &ddev->mode_config.plane_list, head)
888 		drm_plane_cleanup(plane);
889 }
890 
891 static int ltdc_crtc_init(struct drm_device *ddev, struct drm_crtc *crtc)
892 {
893 	struct ltdc_device *ldev = ddev->dev_private;
894 	struct drm_plane *primary, *overlay;
895 	unsigned int i;
896 	int ret;
897 
898 	primary = ltdc_plane_create(ddev, DRM_PLANE_TYPE_PRIMARY);
899 	if (!primary) {
900 		DRM_ERROR("Can not create primary plane\n");
901 		return -EINVAL;
902 	}
903 
904 	ret = drm_crtc_init_with_planes(ddev, crtc, primary, NULL,
905 					&ltdc_crtc_funcs, NULL);
906 	if (ret) {
907 		DRM_ERROR("Can not initialize CRTC\n");
908 		goto cleanup;
909 	}
910 
911 	drm_crtc_helper_add(crtc, &ltdc_crtc_helper_funcs);
912 
913 	drm_mode_crtc_set_gamma_size(crtc, CLUT_SIZE);
914 	drm_crtc_enable_color_mgmt(crtc, 0, false, CLUT_SIZE);
915 
916 	DRM_DEBUG_DRIVER("CRTC:%d created\n", crtc->base.id);
917 
918 	/* Add planes. Note : the first layer is used by primary plane */
919 	for (i = 1; i < ldev->caps.nb_layers; i++) {
920 		overlay = ltdc_plane_create(ddev, DRM_PLANE_TYPE_OVERLAY);
921 		if (!overlay) {
922 			ret = -ENOMEM;
923 			DRM_ERROR("Can not create overlay plane %d\n", i);
924 			goto cleanup;
925 		}
926 	}
927 
928 	return 0;
929 
930 cleanup:
931 	ltdc_plane_destroy_all(ddev);
932 	return ret;
933 }
934 
935 /*
936  * DRM_ENCODER
937  */
938 
939 static const struct drm_encoder_funcs ltdc_encoder_funcs = {
940 	.destroy = drm_encoder_cleanup,
941 };
942 
943 static int ltdc_encoder_init(struct drm_device *ddev, struct drm_bridge *bridge)
944 {
945 	struct drm_encoder *encoder;
946 	int ret;
947 
948 	encoder = devm_kzalloc(ddev->dev, sizeof(*encoder), GFP_KERNEL);
949 	if (!encoder)
950 		return -ENOMEM;
951 
952 	encoder->possible_crtcs = CRTC_MASK;
953 	encoder->possible_clones = 0;	/* No cloning support */
954 
955 	drm_encoder_init(ddev, encoder, &ltdc_encoder_funcs,
956 			 DRM_MODE_ENCODER_DPI, NULL);
957 
958 	ret = drm_bridge_attach(encoder, bridge, NULL);
959 	if (ret) {
960 		drm_encoder_cleanup(encoder);
961 		return -EINVAL;
962 	}
963 
964 	DRM_DEBUG_DRIVER("Bridge encoder:%d created\n", encoder->base.id);
965 
966 	return 0;
967 }
968 
969 static int ltdc_get_caps(struct drm_device *ddev)
970 {
971 	struct ltdc_device *ldev = ddev->dev_private;
972 	u32 bus_width_log2, lcr, gc2r;
973 
974 	/* at least 1 layer must be managed */
975 	lcr = reg_read(ldev->regs, LTDC_LCR);
976 
977 	ldev->caps.nb_layers = max_t(int, lcr, 1);
978 
979 	/* set data bus width */
980 	gc2r = reg_read(ldev->regs, LTDC_GC2R);
981 	bus_width_log2 = (gc2r & GC2R_BW) >> 4;
982 	ldev->caps.bus_width = 8 << bus_width_log2;
983 	ldev->caps.hw_version = reg_read(ldev->regs, LTDC_IDR);
984 
985 	switch (ldev->caps.hw_version) {
986 	case HWVER_10200:
987 	case HWVER_10300:
988 		ldev->caps.reg_ofs = REG_OFS_NONE;
989 		ldev->caps.pix_fmt_hw = ltdc_pix_fmt_a0;
990 		/*
991 		 * Hw older versions support non-alpha color formats derived
992 		 * from native alpha color formats only on the primary layer.
993 		 * For instance, RG16 native format without alpha works fine
994 		 * on 2nd layer but XR24 (derived color format from AR24)
995 		 * does not work on 2nd layer.
996 		 */
997 		ldev->caps.non_alpha_only_l1 = true;
998 		ldev->caps.pad_max_freq_hz = 90000000;
999 		if (ldev->caps.hw_version == HWVER_10200)
1000 			ldev->caps.pad_max_freq_hz = 65000000;
1001 		break;
1002 	case HWVER_20101:
1003 		ldev->caps.reg_ofs = REG_OFS_4;
1004 		ldev->caps.pix_fmt_hw = ltdc_pix_fmt_a1;
1005 		ldev->caps.non_alpha_only_l1 = false;
1006 		ldev->caps.pad_max_freq_hz = 150000000;
1007 		break;
1008 	default:
1009 		return -ENODEV;
1010 	}
1011 
1012 	return 0;
1013 }
1014 
1015 int ltdc_load(struct drm_device *ddev)
1016 {
1017 	struct platform_device *pdev = to_platform_device(ddev->dev);
1018 	struct ltdc_device *ldev = ddev->dev_private;
1019 	struct device *dev = ddev->dev;
1020 	struct device_node *np = dev->of_node;
1021 	struct drm_bridge *bridge[MAX_ENDPOINTS] = {NULL};
1022 	struct drm_panel *panel[MAX_ENDPOINTS] = {NULL};
1023 	struct drm_crtc *crtc;
1024 	struct reset_control *rstc;
1025 	struct resource *res;
1026 	int irq, ret, i, endpoint_not_ready = -ENODEV;
1027 
1028 	DRM_DEBUG_DRIVER("\n");
1029 
1030 	/* Get endpoints if any */
1031 	for (i = 0; i < MAX_ENDPOINTS; i++) {
1032 		ret = drm_of_find_panel_or_bridge(np, 0, i, &panel[i],
1033 						  &bridge[i]);
1034 
1035 		/*
1036 		 * If at least one endpoint is -EPROBE_DEFER, defer probing,
1037 		 * else if at least one endpoint is ready, continue probing.
1038 		 */
1039 		if (ret == -EPROBE_DEFER)
1040 			return ret;
1041 		else if (!ret)
1042 			endpoint_not_ready = 0;
1043 	}
1044 
1045 	if (endpoint_not_ready)
1046 		return endpoint_not_ready;
1047 
1048 	rstc = devm_reset_control_get_exclusive(dev, NULL);
1049 
1050 	mutex_init(&ldev->err_lock);
1051 
1052 	ldev->pixel_clk = devm_clk_get(dev, "lcd");
1053 	if (IS_ERR(ldev->pixel_clk)) {
1054 		DRM_ERROR("Unable to get lcd clock\n");
1055 		return -ENODEV;
1056 	}
1057 
1058 	if (clk_prepare_enable(ldev->pixel_clk)) {
1059 		DRM_ERROR("Unable to prepare pixel clock\n");
1060 		return -ENODEV;
1061 	}
1062 
1063 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1064 	ldev->regs = devm_ioremap_resource(dev, res);
1065 	if (IS_ERR(ldev->regs)) {
1066 		DRM_ERROR("Unable to get ltdc registers\n");
1067 		ret = PTR_ERR(ldev->regs);
1068 		goto err;
1069 	}
1070 
1071 	for (i = 0; i < MAX_IRQ; i++) {
1072 		irq = platform_get_irq(pdev, i);
1073 		if (irq < 0)
1074 			continue;
1075 
1076 		ret = devm_request_threaded_irq(dev, irq, ltdc_irq,
1077 						ltdc_irq_thread, IRQF_ONESHOT,
1078 						dev_name(dev), ddev);
1079 		if (ret) {
1080 			DRM_ERROR("Failed to register LTDC interrupt\n");
1081 			goto err;
1082 		}
1083 	}
1084 
1085 	if (!IS_ERR(rstc)) {
1086 		reset_control_assert(rstc);
1087 		usleep_range(10, 20);
1088 		reset_control_deassert(rstc);
1089 	}
1090 
1091 	/* Disable interrupts */
1092 	reg_clear(ldev->regs, LTDC_IER,
1093 		  IER_LIE | IER_RRIE | IER_FUIE | IER_TERRIE);
1094 
1095 	ret = ltdc_get_caps(ddev);
1096 	if (ret) {
1097 		DRM_ERROR("hardware identifier (0x%08x) not supported!\n",
1098 			  ldev->caps.hw_version);
1099 		goto err;
1100 	}
1101 
1102 	DRM_INFO("ltdc hw version 0x%08x - ready\n", ldev->caps.hw_version);
1103 
1104 	/* Add endpoints panels or bridges if any */
1105 	for (i = 0; i < MAX_ENDPOINTS; i++) {
1106 		if (panel[i]) {
1107 			bridge[i] = drm_panel_bridge_add(panel[i],
1108 							DRM_MODE_CONNECTOR_DPI);
1109 			if (IS_ERR(bridge[i])) {
1110 				DRM_ERROR("panel-bridge endpoint %d\n", i);
1111 				ret = PTR_ERR(bridge[i]);
1112 				goto err;
1113 			}
1114 		}
1115 
1116 		if (bridge[i]) {
1117 			ret = ltdc_encoder_init(ddev, bridge[i]);
1118 			if (ret) {
1119 				DRM_ERROR("init encoder endpoint %d\n", i);
1120 				goto err;
1121 			}
1122 		}
1123 	}
1124 
1125 	crtc = devm_kzalloc(dev, sizeof(*crtc), GFP_KERNEL);
1126 	if (!crtc) {
1127 		DRM_ERROR("Failed to allocate crtc\n");
1128 		ret = -ENOMEM;
1129 		goto err;
1130 	}
1131 
1132 	ret = ltdc_crtc_init(ddev, crtc);
1133 	if (ret) {
1134 		DRM_ERROR("Failed to init crtc\n");
1135 		goto err;
1136 	}
1137 
1138 	ret = drm_vblank_init(ddev, NB_CRTC);
1139 	if (ret) {
1140 		DRM_ERROR("Failed calling drm_vblank_init()\n");
1141 		goto err;
1142 	}
1143 
1144 	/* Allow usage of vblank without having to call drm_irq_install */
1145 	ddev->irq_enabled = 1;
1146 
1147 	return 0;
1148 
1149 err:
1150 	for (i = 0; i < MAX_ENDPOINTS; i++)
1151 		drm_panel_bridge_remove(bridge[i]);
1152 
1153 	clk_disable_unprepare(ldev->pixel_clk);
1154 
1155 	return ret;
1156 }
1157 
1158 void ltdc_unload(struct drm_device *ddev)
1159 {
1160 	struct ltdc_device *ldev = ddev->dev_private;
1161 	int i;
1162 
1163 	DRM_DEBUG_DRIVER("\n");
1164 
1165 	for (i = 0; i < MAX_ENDPOINTS; i++)
1166 		drm_of_panel_bridge_remove(ddev->dev->of_node, 0, i);
1167 
1168 	clk_disable_unprepare(ldev->pixel_clk);
1169 }
1170 
1171 MODULE_AUTHOR("Philippe Cornu <philippe.cornu@st.com>");
1172 MODULE_AUTHOR("Yannick Fertre <yannick.fertre@st.com>");
1173 MODULE_AUTHOR("Fabien Dessenne <fabien.dessenne@st.com>");
1174 MODULE_AUTHOR("Mickael Reulier <mickael.reulier@st.com>");
1175 MODULE_DESCRIPTION("STMicroelectronics ST DRM LTDC driver");
1176 MODULE_LICENSE("GPL v2");
1177