xref: /openbmc/linux/drivers/gpu/drm/stm/ltdc.c (revision d0e22329)
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 CPSR_CYPOS	GENMASK(15, 0)	/* Current Y position */
152 
153 #define ISR_LIF		BIT(0)		/* Line Interrupt Flag */
154 #define ISR_FUIF	BIT(1)		/* Fifo Underrun Interrupt Flag */
155 #define ISR_TERRIF	BIT(2)		/* Transfer ERRor Interrupt Flag */
156 #define ISR_RRIF	BIT(3)		/* Register Reload Interrupt Flag */
157 
158 #define LXCR_LEN	BIT(0)		/* Layer ENable */
159 #define LXCR_COLKEN	BIT(1)		/* Color Keying Enable */
160 #define LXCR_CLUTEN	BIT(4)		/* Color Look-Up Table ENable */
161 
162 #define LXWHPCR_WHSTPOS	GENMASK(11, 0)	/* Window Horizontal StarT POSition */
163 #define LXWHPCR_WHSPPOS	GENMASK(27, 16)	/* Window Horizontal StoP POSition */
164 
165 #define LXWVPCR_WVSTPOS	GENMASK(10, 0)	/* Window Vertical StarT POSition */
166 #define LXWVPCR_WVSPPOS	GENMASK(26, 16)	/* Window Vertical StoP POSition */
167 
168 #define LXPFCR_PF	GENMASK(2, 0)	/* Pixel Format */
169 
170 #define LXCACR_CONSTA	GENMASK(7, 0)	/* CONSTant Alpha */
171 
172 #define LXBFCR_BF2	GENMASK(2, 0)	/* Blending Factor 2 */
173 #define LXBFCR_BF1	GENMASK(10, 8)	/* Blending Factor 1 */
174 
175 #define LXCFBLR_CFBLL	GENMASK(12, 0)	/* Color Frame Buffer Line Length */
176 #define LXCFBLR_CFBP	GENMASK(28, 16)	/* Color Frame Buffer Pitch in bytes */
177 
178 #define LXCFBLNR_CFBLN	GENMASK(10, 0)	/* Color Frame Buffer Line Number */
179 
180 #define CLUT_SIZE	256
181 
182 #define CONSTA_MAX	0xFF		/* CONSTant Alpha MAX= 1.0 */
183 #define BF1_PAXCA	0x600		/* Pixel Alpha x Constant Alpha */
184 #define BF1_CA		0x400		/* Constant Alpha */
185 #define BF2_1PAXCA	0x007		/* 1 - (Pixel Alpha x Constant Alpha) */
186 #define BF2_1CA		0x005		/* 1 - Constant Alpha */
187 
188 #define NB_PF		8		/* Max nb of HW pixel format */
189 
190 enum ltdc_pix_fmt {
191 	PF_NONE,
192 	/* RGB formats */
193 	PF_ARGB8888,		/* ARGB [32 bits] */
194 	PF_RGBA8888,		/* RGBA [32 bits] */
195 	PF_RGB888,		/* RGB [24 bits] */
196 	PF_RGB565,		/* RGB [16 bits] */
197 	PF_ARGB1555,		/* ARGB A:1 bit RGB:15 bits [16 bits] */
198 	PF_ARGB4444,		/* ARGB A:4 bits R/G/B: 4 bits each [16 bits] */
199 	/* Indexed formats */
200 	PF_L8,			/* Indexed 8 bits [8 bits] */
201 	PF_AL44,		/* Alpha:4 bits + indexed 4 bits [8 bits] */
202 	PF_AL88			/* Alpha:8 bits + indexed 8 bits [16 bits] */
203 };
204 
205 /* The index gives the encoding of the pixel format for an HW version */
206 static const enum ltdc_pix_fmt ltdc_pix_fmt_a0[NB_PF] = {
207 	PF_ARGB8888,		/* 0x00 */
208 	PF_RGB888,		/* 0x01 */
209 	PF_RGB565,		/* 0x02 */
210 	PF_ARGB1555,		/* 0x03 */
211 	PF_ARGB4444,		/* 0x04 */
212 	PF_L8,			/* 0x05 */
213 	PF_AL44,		/* 0x06 */
214 	PF_AL88			/* 0x07 */
215 };
216 
217 static const enum ltdc_pix_fmt ltdc_pix_fmt_a1[NB_PF] = {
218 	PF_ARGB8888,		/* 0x00 */
219 	PF_RGB888,		/* 0x01 */
220 	PF_RGB565,		/* 0x02 */
221 	PF_RGBA8888,		/* 0x03 */
222 	PF_AL44,		/* 0x04 */
223 	PF_L8,			/* 0x05 */
224 	PF_ARGB1555,		/* 0x06 */
225 	PF_ARGB4444		/* 0x07 */
226 };
227 
228 static inline u32 reg_read(void __iomem *base, u32 reg)
229 {
230 	return readl_relaxed(base + reg);
231 }
232 
233 static inline void reg_write(void __iomem *base, u32 reg, u32 val)
234 {
235 	writel_relaxed(val, base + reg);
236 }
237 
238 static inline void reg_set(void __iomem *base, u32 reg, u32 mask)
239 {
240 	reg_write(base, reg, reg_read(base, reg) | mask);
241 }
242 
243 static inline void reg_clear(void __iomem *base, u32 reg, u32 mask)
244 {
245 	reg_write(base, reg, reg_read(base, reg) & ~mask);
246 }
247 
248 static inline void reg_update_bits(void __iomem *base, u32 reg, u32 mask,
249 				   u32 val)
250 {
251 	reg_write(base, reg, (reg_read(base, reg) & ~mask) | val);
252 }
253 
254 static inline struct ltdc_device *crtc_to_ltdc(struct drm_crtc *crtc)
255 {
256 	return (struct ltdc_device *)crtc->dev->dev_private;
257 }
258 
259 static inline struct ltdc_device *plane_to_ltdc(struct drm_plane *plane)
260 {
261 	return (struct ltdc_device *)plane->dev->dev_private;
262 }
263 
264 static inline struct ltdc_device *encoder_to_ltdc(struct drm_encoder *enc)
265 {
266 	return (struct ltdc_device *)enc->dev->dev_private;
267 }
268 
269 static inline enum ltdc_pix_fmt to_ltdc_pixelformat(u32 drm_fmt)
270 {
271 	enum ltdc_pix_fmt pf;
272 
273 	switch (drm_fmt) {
274 	case DRM_FORMAT_ARGB8888:
275 	case DRM_FORMAT_XRGB8888:
276 		pf = PF_ARGB8888;
277 		break;
278 	case DRM_FORMAT_RGBA8888:
279 	case DRM_FORMAT_RGBX8888:
280 		pf = PF_RGBA8888;
281 		break;
282 	case DRM_FORMAT_RGB888:
283 		pf = PF_RGB888;
284 		break;
285 	case DRM_FORMAT_RGB565:
286 		pf = PF_RGB565;
287 		break;
288 	case DRM_FORMAT_ARGB1555:
289 	case DRM_FORMAT_XRGB1555:
290 		pf = PF_ARGB1555;
291 		break;
292 	case DRM_FORMAT_ARGB4444:
293 	case DRM_FORMAT_XRGB4444:
294 		pf = PF_ARGB4444;
295 		break;
296 	case DRM_FORMAT_C8:
297 		pf = PF_L8;
298 		break;
299 	default:
300 		pf = PF_NONE;
301 		break;
302 		/* Note: There are no DRM_FORMAT for AL44 and AL88 */
303 	}
304 
305 	return pf;
306 }
307 
308 static inline u32 to_drm_pixelformat(enum ltdc_pix_fmt pf)
309 {
310 	switch (pf) {
311 	case PF_ARGB8888:
312 		return DRM_FORMAT_ARGB8888;
313 	case PF_RGBA8888:
314 		return DRM_FORMAT_RGBA8888;
315 	case PF_RGB888:
316 		return DRM_FORMAT_RGB888;
317 	case PF_RGB565:
318 		return DRM_FORMAT_RGB565;
319 	case PF_ARGB1555:
320 		return DRM_FORMAT_ARGB1555;
321 	case PF_ARGB4444:
322 		return DRM_FORMAT_ARGB4444;
323 	case PF_L8:
324 		return DRM_FORMAT_C8;
325 	case PF_AL44:		/* No DRM support */
326 	case PF_AL88:		/* No DRM support */
327 	case PF_NONE:
328 	default:
329 		return 0;
330 	}
331 }
332 
333 static inline u32 get_pixelformat_without_alpha(u32 drm)
334 {
335 	switch (drm) {
336 	case DRM_FORMAT_ARGB4444:
337 		return DRM_FORMAT_XRGB4444;
338 	case DRM_FORMAT_RGBA4444:
339 		return DRM_FORMAT_RGBX4444;
340 	case DRM_FORMAT_ARGB1555:
341 		return DRM_FORMAT_XRGB1555;
342 	case DRM_FORMAT_RGBA5551:
343 		return DRM_FORMAT_RGBX5551;
344 	case DRM_FORMAT_ARGB8888:
345 		return DRM_FORMAT_XRGB8888;
346 	case DRM_FORMAT_RGBA8888:
347 		return DRM_FORMAT_RGBX8888;
348 	default:
349 		return 0;
350 	}
351 }
352 
353 static irqreturn_t ltdc_irq_thread(int irq, void *arg)
354 {
355 	struct drm_device *ddev = arg;
356 	struct ltdc_device *ldev = ddev->dev_private;
357 	struct drm_crtc *crtc = drm_crtc_from_index(ddev, 0);
358 
359 	/* Line IRQ : trigger the vblank event */
360 	if (ldev->irq_status & ISR_LIF)
361 		drm_crtc_handle_vblank(crtc);
362 
363 	/* Save FIFO Underrun & Transfer Error status */
364 	mutex_lock(&ldev->err_lock);
365 	if (ldev->irq_status & ISR_FUIF)
366 		ldev->error_status |= ISR_FUIF;
367 	if (ldev->irq_status & ISR_TERRIF)
368 		ldev->error_status |= ISR_TERRIF;
369 	mutex_unlock(&ldev->err_lock);
370 
371 	return IRQ_HANDLED;
372 }
373 
374 static irqreturn_t ltdc_irq(int irq, void *arg)
375 {
376 	struct drm_device *ddev = arg;
377 	struct ltdc_device *ldev = ddev->dev_private;
378 
379 	/* Read & Clear the interrupt status */
380 	ldev->irq_status = reg_read(ldev->regs, LTDC_ISR);
381 	reg_write(ldev->regs, LTDC_ICR, ldev->irq_status);
382 
383 	return IRQ_WAKE_THREAD;
384 }
385 
386 /*
387  * DRM_CRTC
388  */
389 
390 static void ltdc_crtc_update_clut(struct drm_crtc *crtc)
391 {
392 	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
393 	struct drm_color_lut *lut;
394 	u32 val;
395 	int i;
396 
397 	if (!crtc->state->color_mgmt_changed || !crtc->state->gamma_lut)
398 		return;
399 
400 	lut = (struct drm_color_lut *)crtc->state->gamma_lut->data;
401 
402 	for (i = 0; i < CLUT_SIZE; i++, lut++) {
403 		val = ((lut->red << 8) & 0xff0000) | (lut->green & 0xff00) |
404 			(lut->blue >> 8) | (i << 24);
405 		reg_write(ldev->regs, LTDC_L1CLUTWR, val);
406 	}
407 }
408 
409 static void ltdc_crtc_atomic_enable(struct drm_crtc *crtc,
410 				    struct drm_crtc_state *old_state)
411 {
412 	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
413 
414 	DRM_DEBUG_DRIVER("\n");
415 
416 	/* Sets the background color value */
417 	reg_write(ldev->regs, LTDC_BCCR, BCCR_BCBLACK);
418 
419 	/* Enable IRQ */
420 	reg_set(ldev->regs, LTDC_IER, IER_RRIE | IER_FUIE | IER_TERRIE);
421 
422 	/* Immediately commit the planes */
423 	reg_set(ldev->regs, LTDC_SRCR, SRCR_IMR);
424 
425 	/* Enable LTDC */
426 	reg_set(ldev->regs, LTDC_GCR, GCR_LTDCEN);
427 
428 	drm_crtc_vblank_on(crtc);
429 }
430 
431 static void ltdc_crtc_atomic_disable(struct drm_crtc *crtc,
432 				     struct drm_crtc_state *old_state)
433 {
434 	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
435 
436 	DRM_DEBUG_DRIVER("\n");
437 
438 	drm_crtc_vblank_off(crtc);
439 
440 	/* disable LTDC */
441 	reg_clear(ldev->regs, LTDC_GCR, GCR_LTDCEN);
442 
443 	/* disable IRQ */
444 	reg_clear(ldev->regs, LTDC_IER, IER_RRIE | IER_FUIE | IER_TERRIE);
445 
446 	/* immediately commit disable of layers before switching off LTDC */
447 	reg_set(ldev->regs, LTDC_SRCR, SRCR_IMR);
448 }
449 
450 #define CLK_TOLERANCE_HZ 50
451 
452 static enum drm_mode_status
453 ltdc_crtc_mode_valid(struct drm_crtc *crtc,
454 		     const struct drm_display_mode *mode)
455 {
456 	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
457 	int target = mode->clock * 1000;
458 	int target_min = target - CLK_TOLERANCE_HZ;
459 	int target_max = target + CLK_TOLERANCE_HZ;
460 	int result;
461 
462 	result = clk_round_rate(ldev->pixel_clk, target);
463 
464 	DRM_DEBUG_DRIVER("clk rate target %d, available %d\n", target, result);
465 
466 	/* Filter modes according to the max frequency supported by the pads */
467 	if (result > ldev->caps.pad_max_freq_hz)
468 		return MODE_CLOCK_HIGH;
469 
470 	/*
471 	 * Accept all "preferred" modes:
472 	 * - this is important for panels because panel clock tolerances are
473 	 *   bigger than hdmi ones and there is no reason to not accept them
474 	 *   (the fps may vary a little but it is not a problem).
475 	 * - the hdmi preferred mode will be accepted too, but userland will
476 	 *   be able to use others hdmi "valid" modes if necessary.
477 	 */
478 	if (mode->type & DRM_MODE_TYPE_PREFERRED)
479 		return MODE_OK;
480 
481 	/*
482 	 * Filter modes according to the clock value, particularly useful for
483 	 * hdmi modes that require precise pixel clocks.
484 	 */
485 	if (result < target_min || result > target_max)
486 		return MODE_CLOCK_RANGE;
487 
488 	return MODE_OK;
489 }
490 
491 static bool ltdc_crtc_mode_fixup(struct drm_crtc *crtc,
492 				 const struct drm_display_mode *mode,
493 				 struct drm_display_mode *adjusted_mode)
494 {
495 	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
496 	int rate = mode->clock * 1000;
497 
498 	/*
499 	 * TODO clk_round_rate() does not work yet. When ready, it can
500 	 * be used instead of clk_set_rate() then clk_get_rate().
501 	 */
502 
503 	clk_disable(ldev->pixel_clk);
504 	if (clk_set_rate(ldev->pixel_clk, rate) < 0) {
505 		DRM_ERROR("Cannot set rate (%dHz) for pixel clk\n", rate);
506 		return false;
507 	}
508 	clk_enable(ldev->pixel_clk);
509 
510 	adjusted_mode->clock = clk_get_rate(ldev->pixel_clk) / 1000;
511 
512 	return true;
513 }
514 
515 static void ltdc_crtc_mode_set_nofb(struct drm_crtc *crtc)
516 {
517 	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
518 	struct drm_display_mode *mode = &crtc->state->adjusted_mode;
519 	struct videomode vm;
520 	u32 hsync, vsync, accum_hbp, accum_vbp, accum_act_w, accum_act_h;
521 	u32 total_width, total_height;
522 	u32 val;
523 
524 	drm_display_mode_to_videomode(mode, &vm);
525 
526 	DRM_DEBUG_DRIVER("CRTC:%d mode:%s\n", crtc->base.id, mode->name);
527 	DRM_DEBUG_DRIVER("Video mode: %dx%d", vm.hactive, vm.vactive);
528 	DRM_DEBUG_DRIVER(" hfp %d hbp %d hsl %d vfp %d vbp %d vsl %d\n",
529 			 vm.hfront_porch, vm.hback_porch, vm.hsync_len,
530 			 vm.vfront_porch, vm.vback_porch, vm.vsync_len);
531 
532 	/* Convert video timings to ltdc timings */
533 	hsync = vm.hsync_len - 1;
534 	vsync = vm.vsync_len - 1;
535 	accum_hbp = hsync + vm.hback_porch;
536 	accum_vbp = vsync + vm.vback_porch;
537 	accum_act_w = accum_hbp + vm.hactive;
538 	accum_act_h = accum_vbp + vm.vactive;
539 	total_width = accum_act_w + vm.hfront_porch;
540 	total_height = accum_act_h + vm.vfront_porch;
541 
542 	/* Configures the HS, VS, DE and PC polarities. Default Active Low */
543 	val = 0;
544 
545 	if (vm.flags & DISPLAY_FLAGS_HSYNC_HIGH)
546 		val |= GCR_HSPOL;
547 
548 	if (vm.flags & DISPLAY_FLAGS_VSYNC_HIGH)
549 		val |= GCR_VSPOL;
550 
551 	if (vm.flags & DISPLAY_FLAGS_DE_HIGH)
552 		val |= GCR_DEPOL;
553 
554 	if (vm.flags & DISPLAY_FLAGS_PIXDATA_NEGEDGE)
555 		val |= GCR_PCPOL;
556 
557 	reg_update_bits(ldev->regs, LTDC_GCR,
558 			GCR_HSPOL | GCR_VSPOL | GCR_DEPOL | GCR_PCPOL, val);
559 
560 	/* Set Synchronization size */
561 	val = (hsync << 16) | vsync;
562 	reg_update_bits(ldev->regs, LTDC_SSCR, SSCR_VSH | SSCR_HSW, val);
563 
564 	/* Set Accumulated Back porch */
565 	val = (accum_hbp << 16) | accum_vbp;
566 	reg_update_bits(ldev->regs, LTDC_BPCR, BPCR_AVBP | BPCR_AHBP, val);
567 
568 	/* Set Accumulated Active Width */
569 	val = (accum_act_w << 16) | accum_act_h;
570 	reg_update_bits(ldev->regs, LTDC_AWCR, AWCR_AAW | AWCR_AAH, val);
571 
572 	/* Set total width & height */
573 	val = (total_width << 16) | total_height;
574 	reg_update_bits(ldev->regs, LTDC_TWCR, TWCR_TOTALH | TWCR_TOTALW, val);
575 
576 	reg_write(ldev->regs, LTDC_LIPCR, (accum_act_h + 1));
577 }
578 
579 static void ltdc_crtc_atomic_flush(struct drm_crtc *crtc,
580 				   struct drm_crtc_state *old_crtc_state)
581 {
582 	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
583 	struct drm_pending_vblank_event *event = crtc->state->event;
584 
585 	DRM_DEBUG_ATOMIC("\n");
586 
587 	ltdc_crtc_update_clut(crtc);
588 
589 	/* Commit shadow registers = update planes at next vblank */
590 	reg_set(ldev->regs, LTDC_SRCR, SRCR_VBR);
591 
592 	if (event) {
593 		crtc->state->event = NULL;
594 
595 		spin_lock_irq(&crtc->dev->event_lock);
596 		if (drm_crtc_vblank_get(crtc) == 0)
597 			drm_crtc_arm_vblank_event(crtc, event);
598 		else
599 			drm_crtc_send_vblank_event(crtc, event);
600 		spin_unlock_irq(&crtc->dev->event_lock);
601 	}
602 }
603 
604 static const struct drm_crtc_helper_funcs ltdc_crtc_helper_funcs = {
605 	.mode_valid = ltdc_crtc_mode_valid,
606 	.mode_fixup = ltdc_crtc_mode_fixup,
607 	.mode_set_nofb = ltdc_crtc_mode_set_nofb,
608 	.atomic_flush = ltdc_crtc_atomic_flush,
609 	.atomic_enable = ltdc_crtc_atomic_enable,
610 	.atomic_disable = ltdc_crtc_atomic_disable,
611 };
612 
613 static int ltdc_crtc_enable_vblank(struct drm_crtc *crtc)
614 {
615 	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
616 
617 	DRM_DEBUG_DRIVER("\n");
618 	reg_set(ldev->regs, LTDC_IER, IER_LIE);
619 
620 	return 0;
621 }
622 
623 static void ltdc_crtc_disable_vblank(struct drm_crtc *crtc)
624 {
625 	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
626 
627 	DRM_DEBUG_DRIVER("\n");
628 	reg_clear(ldev->regs, LTDC_IER, IER_LIE);
629 }
630 
631 bool ltdc_crtc_scanoutpos(struct drm_device *ddev, unsigned int pipe,
632 			  bool in_vblank_irq, int *vpos, int *hpos,
633 			  ktime_t *stime, ktime_t *etime,
634 			  const struct drm_display_mode *mode)
635 {
636 	struct ltdc_device *ldev = ddev->dev_private;
637 	int line, vactive_start, vactive_end, vtotal;
638 
639 	if (stime)
640 		*stime = ktime_get();
641 
642 	/* The active area starts after vsync + front porch and ends
643 	 * at vsync + front porc + display size.
644 	 * The total height also include back porch.
645 	 * We have 3 possible cases to handle:
646 	 * - line < vactive_start: vpos = line - vactive_start and will be
647 	 * negative
648 	 * - vactive_start < line < vactive_end: vpos = line - vactive_start
649 	 * and will be positive
650 	 * - line > vactive_end: vpos = line - vtotal - vactive_start
651 	 * and will negative
652 	 *
653 	 * Computation for the two first cases are identical so we can
654 	 * simplify the code and only test if line > vactive_end
655 	 */
656 	line = reg_read(ldev->regs, LTDC_CPSR) & CPSR_CYPOS;
657 	vactive_start = reg_read(ldev->regs, LTDC_BPCR) & BPCR_AVBP;
658 	vactive_end = reg_read(ldev->regs, LTDC_AWCR) & AWCR_AAH;
659 	vtotal = reg_read(ldev->regs, LTDC_TWCR) & TWCR_TOTALH;
660 
661 	if (line > vactive_end)
662 		*vpos = line - vtotal - vactive_start;
663 	else
664 		*vpos = line - vactive_start;
665 
666 	*hpos = 0;
667 
668 	if (etime)
669 		*etime = ktime_get();
670 
671 	return true;
672 }
673 
674 static const struct drm_crtc_funcs ltdc_crtc_funcs = {
675 	.destroy = drm_crtc_cleanup,
676 	.set_config = drm_atomic_helper_set_config,
677 	.page_flip = drm_atomic_helper_page_flip,
678 	.reset = drm_atomic_helper_crtc_reset,
679 	.atomic_duplicate_state = drm_atomic_helper_crtc_duplicate_state,
680 	.atomic_destroy_state = drm_atomic_helper_crtc_destroy_state,
681 	.enable_vblank = ltdc_crtc_enable_vblank,
682 	.disable_vblank = ltdc_crtc_disable_vblank,
683 	.gamma_set = drm_atomic_helper_legacy_gamma_set,
684 };
685 
686 /*
687  * DRM_PLANE
688  */
689 
690 static int ltdc_plane_atomic_check(struct drm_plane *plane,
691 				   struct drm_plane_state *state)
692 {
693 	struct drm_framebuffer *fb = state->fb;
694 	u32 src_x, src_y, src_w, src_h;
695 
696 	DRM_DEBUG_DRIVER("\n");
697 
698 	if (!fb)
699 		return 0;
700 
701 	/* convert src_ from 16:16 format */
702 	src_x = state->src_x >> 16;
703 	src_y = state->src_y >> 16;
704 	src_w = state->src_w >> 16;
705 	src_h = state->src_h >> 16;
706 
707 	/* Reject scaling */
708 	if (src_w != state->crtc_w || src_h != state->crtc_h) {
709 		DRM_ERROR("Scaling is not supported");
710 		return -EINVAL;
711 	}
712 
713 	return 0;
714 }
715 
716 static void ltdc_plane_atomic_update(struct drm_plane *plane,
717 				     struct drm_plane_state *oldstate)
718 {
719 	struct ltdc_device *ldev = plane_to_ltdc(plane);
720 	struct drm_plane_state *state = plane->state;
721 	struct drm_framebuffer *fb = state->fb;
722 	u32 lofs = plane->index * LAY_OFS;
723 	u32 x0 = state->crtc_x;
724 	u32 x1 = state->crtc_x + state->crtc_w - 1;
725 	u32 y0 = state->crtc_y;
726 	u32 y1 = state->crtc_y + state->crtc_h - 1;
727 	u32 src_x, src_y, src_w, src_h;
728 	u32 val, pitch_in_bytes, line_length, paddr, ahbp, avbp, bpcr;
729 	enum ltdc_pix_fmt pf;
730 
731 	if (!state->crtc || !fb) {
732 		DRM_DEBUG_DRIVER("fb or crtc NULL");
733 		return;
734 	}
735 
736 	/* convert src_ from 16:16 format */
737 	src_x = state->src_x >> 16;
738 	src_y = state->src_y >> 16;
739 	src_w = state->src_w >> 16;
740 	src_h = state->src_h >> 16;
741 
742 	DRM_DEBUG_DRIVER("plane:%d fb:%d (%dx%d)@(%d,%d) -> (%dx%d)@(%d,%d)\n",
743 			 plane->base.id, fb->base.id,
744 			 src_w, src_h, src_x, src_y,
745 			 state->crtc_w, state->crtc_h,
746 			 state->crtc_x, state->crtc_y);
747 
748 	bpcr = reg_read(ldev->regs, LTDC_BPCR);
749 	ahbp = (bpcr & BPCR_AHBP) >> 16;
750 	avbp = bpcr & BPCR_AVBP;
751 
752 	/* Configures the horizontal start and stop position */
753 	val = ((x1 + 1 + ahbp) << 16) + (x0 + 1 + ahbp);
754 	reg_update_bits(ldev->regs, LTDC_L1WHPCR + lofs,
755 			LXWHPCR_WHSTPOS | LXWHPCR_WHSPPOS, val);
756 
757 	/* Configures the vertical start and stop position */
758 	val = ((y1 + 1 + avbp) << 16) + (y0 + 1 + avbp);
759 	reg_update_bits(ldev->regs, LTDC_L1WVPCR + lofs,
760 			LXWVPCR_WVSTPOS | LXWVPCR_WVSPPOS, val);
761 
762 	/* Specifies the pixel format */
763 	pf = to_ltdc_pixelformat(fb->format->format);
764 	for (val = 0; val < NB_PF; val++)
765 		if (ldev->caps.pix_fmt_hw[val] == pf)
766 			break;
767 
768 	if (val == NB_PF) {
769 		DRM_ERROR("Pixel format %.4s not supported\n",
770 			  (char *)&fb->format->format);
771 		val = 0;	/* set by default ARGB 32 bits */
772 	}
773 	reg_update_bits(ldev->regs, LTDC_L1PFCR + lofs, LXPFCR_PF, val);
774 
775 	/* Configures the color frame buffer pitch in bytes & line length */
776 	pitch_in_bytes = fb->pitches[0];
777 	line_length = drm_format_plane_cpp(fb->format->format, 0) *
778 		      (x1 - x0 + 1) + (ldev->caps.bus_width >> 3) - 1;
779 	val = ((pitch_in_bytes << 16) | line_length);
780 	reg_update_bits(ldev->regs, LTDC_L1CFBLR + lofs,
781 			LXCFBLR_CFBLL | LXCFBLR_CFBP, val);
782 
783 	/* Specifies the constant alpha value */
784 	val = CONSTA_MAX;
785 	reg_update_bits(ldev->regs, LTDC_L1CACR + lofs, LXCACR_CONSTA, val);
786 
787 	/* Specifies the blending factors */
788 	val = BF1_PAXCA | BF2_1PAXCA;
789 	if (!fb->format->has_alpha)
790 		val = BF1_CA | BF2_1CA;
791 
792 	/* Manage hw-specific capabilities */
793 	if (ldev->caps.non_alpha_only_l1 &&
794 	    plane->type != DRM_PLANE_TYPE_PRIMARY)
795 		val = BF1_PAXCA | BF2_1PAXCA;
796 
797 	reg_update_bits(ldev->regs, LTDC_L1BFCR + lofs,
798 			LXBFCR_BF2 | LXBFCR_BF1, val);
799 
800 	/* Configures the frame buffer line number */
801 	val = y1 - y0 + 1;
802 	reg_update_bits(ldev->regs, LTDC_L1CFBLNR + lofs, LXCFBLNR_CFBLN, val);
803 
804 	/* Sets the FB address */
805 	paddr = (u32)drm_fb_cma_get_gem_addr(fb, state, 0);
806 
807 	DRM_DEBUG_DRIVER("fb: phys 0x%08x", paddr);
808 	reg_write(ldev->regs, LTDC_L1CFBAR + lofs, paddr);
809 
810 	/* Enable layer and CLUT if needed */
811 	val = fb->format->format == DRM_FORMAT_C8 ? LXCR_CLUTEN : 0;
812 	val |= LXCR_LEN;
813 	reg_update_bits(ldev->regs, LTDC_L1CR + lofs,
814 			LXCR_LEN | LXCR_CLUTEN, val);
815 
816 	ldev->plane_fpsi[plane->index].counter++;
817 
818 	mutex_lock(&ldev->err_lock);
819 	if (ldev->error_status & ISR_FUIF) {
820 		DRM_DEBUG_DRIVER("Fifo underrun\n");
821 		ldev->error_status &= ~ISR_FUIF;
822 	}
823 	if (ldev->error_status & ISR_TERRIF) {
824 		DRM_DEBUG_DRIVER("Transfer error\n");
825 		ldev->error_status &= ~ISR_TERRIF;
826 	}
827 	mutex_unlock(&ldev->err_lock);
828 }
829 
830 static void ltdc_plane_atomic_disable(struct drm_plane *plane,
831 				      struct drm_plane_state *oldstate)
832 {
833 	struct ltdc_device *ldev = plane_to_ltdc(plane);
834 	u32 lofs = plane->index * LAY_OFS;
835 
836 	/* disable layer */
837 	reg_clear(ldev->regs, LTDC_L1CR + lofs, LXCR_LEN);
838 
839 	DRM_DEBUG_DRIVER("CRTC:%d plane:%d\n",
840 			 oldstate->crtc->base.id, plane->base.id);
841 }
842 
843 static void ltdc_plane_atomic_print_state(struct drm_printer *p,
844 					  const struct drm_plane_state *state)
845 {
846 	struct drm_plane *plane = state->plane;
847 	struct ltdc_device *ldev = plane_to_ltdc(plane);
848 	struct fps_info *fpsi = &ldev->plane_fpsi[plane->index];
849 	int ms_since_last;
850 	ktime_t now;
851 
852 	now = ktime_get();
853 	ms_since_last = ktime_to_ms(ktime_sub(now, fpsi->last_timestamp));
854 
855 	drm_printf(p, "\tuser_updates=%dfps\n",
856 		   DIV_ROUND_CLOSEST(fpsi->counter * 1000, ms_since_last));
857 
858 	fpsi->last_timestamp = now;
859 	fpsi->counter = 0;
860 }
861 
862 static const struct drm_plane_funcs ltdc_plane_funcs = {
863 	.update_plane = drm_atomic_helper_update_plane,
864 	.disable_plane = drm_atomic_helper_disable_plane,
865 	.destroy = drm_plane_cleanup,
866 	.reset = drm_atomic_helper_plane_reset,
867 	.atomic_duplicate_state = drm_atomic_helper_plane_duplicate_state,
868 	.atomic_destroy_state = drm_atomic_helper_plane_destroy_state,
869 	.atomic_print_state = ltdc_plane_atomic_print_state,
870 };
871 
872 static const struct drm_plane_helper_funcs ltdc_plane_helper_funcs = {
873 	.atomic_check = ltdc_plane_atomic_check,
874 	.atomic_update = ltdc_plane_atomic_update,
875 	.atomic_disable = ltdc_plane_atomic_disable,
876 };
877 
878 static struct drm_plane *ltdc_plane_create(struct drm_device *ddev,
879 					   enum drm_plane_type type)
880 {
881 	unsigned long possible_crtcs = CRTC_MASK;
882 	struct ltdc_device *ldev = ddev->dev_private;
883 	struct device *dev = ddev->dev;
884 	struct drm_plane *plane;
885 	unsigned int i, nb_fmt = 0;
886 	u32 formats[NB_PF * 2];
887 	u32 drm_fmt, drm_fmt_no_alpha;
888 	int ret;
889 
890 	/* Get supported pixel formats */
891 	for (i = 0; i < NB_PF; i++) {
892 		drm_fmt = to_drm_pixelformat(ldev->caps.pix_fmt_hw[i]);
893 		if (!drm_fmt)
894 			continue;
895 		formats[nb_fmt++] = drm_fmt;
896 
897 		/* Add the no-alpha related format if any & supported */
898 		drm_fmt_no_alpha = get_pixelformat_without_alpha(drm_fmt);
899 		if (!drm_fmt_no_alpha)
900 			continue;
901 
902 		/* Manage hw-specific capabilities */
903 		if (ldev->caps.non_alpha_only_l1 &&
904 		    type != DRM_PLANE_TYPE_PRIMARY)
905 			continue;
906 
907 		formats[nb_fmt++] = drm_fmt_no_alpha;
908 	}
909 
910 	plane = devm_kzalloc(dev, sizeof(*plane), GFP_KERNEL);
911 	if (!plane)
912 		return NULL;
913 
914 	ret = drm_universal_plane_init(ddev, plane, possible_crtcs,
915 				       &ltdc_plane_funcs, formats, nb_fmt,
916 				       NULL, type, NULL);
917 	if (ret < 0)
918 		return NULL;
919 
920 	drm_plane_helper_add(plane, &ltdc_plane_helper_funcs);
921 
922 	DRM_DEBUG_DRIVER("plane:%d created\n", plane->base.id);
923 
924 	return plane;
925 }
926 
927 static void ltdc_plane_destroy_all(struct drm_device *ddev)
928 {
929 	struct drm_plane *plane, *plane_temp;
930 
931 	list_for_each_entry_safe(plane, plane_temp,
932 				 &ddev->mode_config.plane_list, head)
933 		drm_plane_cleanup(plane);
934 }
935 
936 static int ltdc_crtc_init(struct drm_device *ddev, struct drm_crtc *crtc)
937 {
938 	struct ltdc_device *ldev = ddev->dev_private;
939 	struct drm_plane *primary, *overlay;
940 	unsigned int i;
941 	int ret;
942 
943 	primary = ltdc_plane_create(ddev, DRM_PLANE_TYPE_PRIMARY);
944 	if (!primary) {
945 		DRM_ERROR("Can not create primary plane\n");
946 		return -EINVAL;
947 	}
948 
949 	ret = drm_crtc_init_with_planes(ddev, crtc, primary, NULL,
950 					&ltdc_crtc_funcs, NULL);
951 	if (ret) {
952 		DRM_ERROR("Can not initialize CRTC\n");
953 		goto cleanup;
954 	}
955 
956 	drm_crtc_helper_add(crtc, &ltdc_crtc_helper_funcs);
957 
958 	drm_mode_crtc_set_gamma_size(crtc, CLUT_SIZE);
959 	drm_crtc_enable_color_mgmt(crtc, 0, false, CLUT_SIZE);
960 
961 	DRM_DEBUG_DRIVER("CRTC:%d created\n", crtc->base.id);
962 
963 	/* Add planes. Note : the first layer is used by primary plane */
964 	for (i = 1; i < ldev->caps.nb_layers; i++) {
965 		overlay = ltdc_plane_create(ddev, DRM_PLANE_TYPE_OVERLAY);
966 		if (!overlay) {
967 			ret = -ENOMEM;
968 			DRM_ERROR("Can not create overlay plane %d\n", i);
969 			goto cleanup;
970 		}
971 	}
972 
973 	return 0;
974 
975 cleanup:
976 	ltdc_plane_destroy_all(ddev);
977 	return ret;
978 }
979 
980 /*
981  * DRM_ENCODER
982  */
983 
984 static const struct drm_encoder_funcs ltdc_encoder_funcs = {
985 	.destroy = drm_encoder_cleanup,
986 };
987 
988 static int ltdc_encoder_init(struct drm_device *ddev, struct drm_bridge *bridge)
989 {
990 	struct drm_encoder *encoder;
991 	int ret;
992 
993 	encoder = devm_kzalloc(ddev->dev, sizeof(*encoder), GFP_KERNEL);
994 	if (!encoder)
995 		return -ENOMEM;
996 
997 	encoder->possible_crtcs = CRTC_MASK;
998 	encoder->possible_clones = 0;	/* No cloning support */
999 
1000 	drm_encoder_init(ddev, encoder, &ltdc_encoder_funcs,
1001 			 DRM_MODE_ENCODER_DPI, NULL);
1002 
1003 	ret = drm_bridge_attach(encoder, bridge, NULL);
1004 	if (ret) {
1005 		drm_encoder_cleanup(encoder);
1006 		return -EINVAL;
1007 	}
1008 
1009 	DRM_DEBUG_DRIVER("Bridge encoder:%d created\n", encoder->base.id);
1010 
1011 	return 0;
1012 }
1013 
1014 static int ltdc_get_caps(struct drm_device *ddev)
1015 {
1016 	struct ltdc_device *ldev = ddev->dev_private;
1017 	u32 bus_width_log2, lcr, gc2r;
1018 
1019 	/* at least 1 layer must be managed */
1020 	lcr = reg_read(ldev->regs, LTDC_LCR);
1021 
1022 	ldev->caps.nb_layers = max_t(int, lcr, 1);
1023 
1024 	/* set data bus width */
1025 	gc2r = reg_read(ldev->regs, LTDC_GC2R);
1026 	bus_width_log2 = (gc2r & GC2R_BW) >> 4;
1027 	ldev->caps.bus_width = 8 << bus_width_log2;
1028 	ldev->caps.hw_version = reg_read(ldev->regs, LTDC_IDR);
1029 
1030 	switch (ldev->caps.hw_version) {
1031 	case HWVER_10200:
1032 	case HWVER_10300:
1033 		ldev->caps.reg_ofs = REG_OFS_NONE;
1034 		ldev->caps.pix_fmt_hw = ltdc_pix_fmt_a0;
1035 		/*
1036 		 * Hw older versions support non-alpha color formats derived
1037 		 * from native alpha color formats only on the primary layer.
1038 		 * For instance, RG16 native format without alpha works fine
1039 		 * on 2nd layer but XR24 (derived color format from AR24)
1040 		 * does not work on 2nd layer.
1041 		 */
1042 		ldev->caps.non_alpha_only_l1 = true;
1043 		ldev->caps.pad_max_freq_hz = 90000000;
1044 		if (ldev->caps.hw_version == HWVER_10200)
1045 			ldev->caps.pad_max_freq_hz = 65000000;
1046 		break;
1047 	case HWVER_20101:
1048 		ldev->caps.reg_ofs = REG_OFS_4;
1049 		ldev->caps.pix_fmt_hw = ltdc_pix_fmt_a1;
1050 		ldev->caps.non_alpha_only_l1 = false;
1051 		ldev->caps.pad_max_freq_hz = 150000000;
1052 		break;
1053 	default:
1054 		return -ENODEV;
1055 	}
1056 
1057 	return 0;
1058 }
1059 
1060 int ltdc_load(struct drm_device *ddev)
1061 {
1062 	struct platform_device *pdev = to_platform_device(ddev->dev);
1063 	struct ltdc_device *ldev = ddev->dev_private;
1064 	struct device *dev = ddev->dev;
1065 	struct device_node *np = dev->of_node;
1066 	struct drm_bridge *bridge[MAX_ENDPOINTS] = {NULL};
1067 	struct drm_panel *panel[MAX_ENDPOINTS] = {NULL};
1068 	struct drm_crtc *crtc;
1069 	struct reset_control *rstc;
1070 	struct resource *res;
1071 	int irq, ret, i, endpoint_not_ready = -ENODEV;
1072 
1073 	DRM_DEBUG_DRIVER("\n");
1074 
1075 	/* Get endpoints if any */
1076 	for (i = 0; i < MAX_ENDPOINTS; i++) {
1077 		ret = drm_of_find_panel_or_bridge(np, 0, i, &panel[i],
1078 						  &bridge[i]);
1079 
1080 		/*
1081 		 * If at least one endpoint is -EPROBE_DEFER, defer probing,
1082 		 * else if at least one endpoint is ready, continue probing.
1083 		 */
1084 		if (ret == -EPROBE_DEFER)
1085 			return ret;
1086 		else if (!ret)
1087 			endpoint_not_ready = 0;
1088 	}
1089 
1090 	if (endpoint_not_ready)
1091 		return endpoint_not_ready;
1092 
1093 	rstc = devm_reset_control_get_exclusive(dev, NULL);
1094 
1095 	mutex_init(&ldev->err_lock);
1096 
1097 	ldev->pixel_clk = devm_clk_get(dev, "lcd");
1098 	if (IS_ERR(ldev->pixel_clk)) {
1099 		DRM_ERROR("Unable to get lcd clock\n");
1100 		return -ENODEV;
1101 	}
1102 
1103 	if (clk_prepare_enable(ldev->pixel_clk)) {
1104 		DRM_ERROR("Unable to prepare pixel clock\n");
1105 		return -ENODEV;
1106 	}
1107 
1108 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1109 	ldev->regs = devm_ioremap_resource(dev, res);
1110 	if (IS_ERR(ldev->regs)) {
1111 		DRM_ERROR("Unable to get ltdc registers\n");
1112 		ret = PTR_ERR(ldev->regs);
1113 		goto err;
1114 	}
1115 
1116 	for (i = 0; i < MAX_IRQ; i++) {
1117 		irq = platform_get_irq(pdev, i);
1118 		if (irq < 0)
1119 			continue;
1120 
1121 		ret = devm_request_threaded_irq(dev, irq, ltdc_irq,
1122 						ltdc_irq_thread, IRQF_ONESHOT,
1123 						dev_name(dev), ddev);
1124 		if (ret) {
1125 			DRM_ERROR("Failed to register LTDC interrupt\n");
1126 			goto err;
1127 		}
1128 	}
1129 
1130 	if (!IS_ERR(rstc)) {
1131 		reset_control_assert(rstc);
1132 		usleep_range(10, 20);
1133 		reset_control_deassert(rstc);
1134 	}
1135 
1136 	/* Disable interrupts */
1137 	reg_clear(ldev->regs, LTDC_IER,
1138 		  IER_LIE | IER_RRIE | IER_FUIE | IER_TERRIE);
1139 
1140 	ret = ltdc_get_caps(ddev);
1141 	if (ret) {
1142 		DRM_ERROR("hardware identifier (0x%08x) not supported!\n",
1143 			  ldev->caps.hw_version);
1144 		goto err;
1145 	}
1146 
1147 	DRM_INFO("ltdc hw version 0x%08x - ready\n", ldev->caps.hw_version);
1148 
1149 	/* Add endpoints panels or bridges if any */
1150 	for (i = 0; i < MAX_ENDPOINTS; i++) {
1151 		if (panel[i]) {
1152 			bridge[i] = drm_panel_bridge_add(panel[i],
1153 							DRM_MODE_CONNECTOR_DPI);
1154 			if (IS_ERR(bridge[i])) {
1155 				DRM_ERROR("panel-bridge endpoint %d\n", i);
1156 				ret = PTR_ERR(bridge[i]);
1157 				goto err;
1158 			}
1159 		}
1160 
1161 		if (bridge[i]) {
1162 			ret = ltdc_encoder_init(ddev, bridge[i]);
1163 			if (ret) {
1164 				DRM_ERROR("init encoder endpoint %d\n", i);
1165 				goto err;
1166 			}
1167 		}
1168 	}
1169 
1170 	crtc = devm_kzalloc(dev, sizeof(*crtc), GFP_KERNEL);
1171 	if (!crtc) {
1172 		DRM_ERROR("Failed to allocate crtc\n");
1173 		ret = -ENOMEM;
1174 		goto err;
1175 	}
1176 
1177 	ret = ltdc_crtc_init(ddev, crtc);
1178 	if (ret) {
1179 		DRM_ERROR("Failed to init crtc\n");
1180 		goto err;
1181 	}
1182 
1183 	ret = drm_vblank_init(ddev, NB_CRTC);
1184 	if (ret) {
1185 		DRM_ERROR("Failed calling drm_vblank_init()\n");
1186 		goto err;
1187 	}
1188 
1189 	/* Allow usage of vblank without having to call drm_irq_install */
1190 	ddev->irq_enabled = 1;
1191 
1192 	return 0;
1193 
1194 err:
1195 	for (i = 0; i < MAX_ENDPOINTS; i++)
1196 		drm_panel_bridge_remove(bridge[i]);
1197 
1198 	clk_disable_unprepare(ldev->pixel_clk);
1199 
1200 	return ret;
1201 }
1202 
1203 void ltdc_unload(struct drm_device *ddev)
1204 {
1205 	struct ltdc_device *ldev = ddev->dev_private;
1206 	int i;
1207 
1208 	DRM_DEBUG_DRIVER("\n");
1209 
1210 	for (i = 0; i < MAX_ENDPOINTS; i++)
1211 		drm_of_panel_bridge_remove(ddev->dev->of_node, 0, i);
1212 
1213 	clk_disable_unprepare(ldev->pixel_clk);
1214 }
1215 
1216 MODULE_AUTHOR("Philippe Cornu <philippe.cornu@st.com>");
1217 MODULE_AUTHOR("Yannick Fertre <yannick.fertre@st.com>");
1218 MODULE_AUTHOR("Fabien Dessenne <fabien.dessenne@st.com>");
1219 MODULE_AUTHOR("Mickael Reulier <mickael.reulier@st.com>");
1220 MODULE_DESCRIPTION("STMicroelectronics ST DRM LTDC driver");
1221 MODULE_LICENSE("GPL v2");
1222