xref: /openbmc/linux/drivers/gpu/drm/stm/ltdc.c (revision 5a158981)
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/delay.h>
14 #include <linux/interrupt.h>
15 #include <linux/module.h>
16 #include <linux/of_address.h>
17 #include <linux/of_graph.h>
18 #include <linux/pinctrl/consumer.h>
19 #include <linux/platform_device.h>
20 #include <linux/pm_runtime.h>
21 #include <linux/reset.h>
22 
23 #include <drm/drm_atomic.h>
24 #include <drm/drm_atomic_helper.h>
25 #include <drm/drm_bridge.h>
26 #include <drm/drm_device.h>
27 #include <drm/drm_fb_cma_helper.h>
28 #include <drm/drm_fourcc.h>
29 #include <drm/drm_gem_cma_helper.h>
30 #include <drm/drm_gem_framebuffer_helper.h>
31 #include <drm/drm_of.h>
32 #include <drm/drm_plane_helper.h>
33 #include <drm/drm_probe_helper.h>
34 #include <drm/drm_vblank.h>
35 
36 #include <video/videomode.h>
37 
38 #include "ltdc.h"
39 
40 #define NB_CRTC 1
41 #define CRTC_MASK GENMASK(NB_CRTC - 1, 0)
42 
43 #define MAX_IRQ 4
44 
45 #define MAX_ENDPOINTS 2
46 
47 #define HWVER_10200 0x010200
48 #define HWVER_10300 0x010300
49 #define HWVER_20101 0x020101
50 
51 /*
52  * The address of some registers depends on the HW version: such registers have
53  * an extra offset specified with reg_ofs.
54  */
55 #define REG_OFS_NONE	0
56 #define REG_OFS_4	4		/* Insertion of "Layer Conf. 2" reg */
57 #define REG_OFS		(ldev->caps.reg_ofs)
58 #define LAY_OFS		0x80		/* Register Offset between 2 layers */
59 
60 /* Global register offsets */
61 #define LTDC_IDR	0x0000		/* IDentification */
62 #define LTDC_LCR	0x0004		/* Layer Count */
63 #define LTDC_SSCR	0x0008		/* Synchronization Size Configuration */
64 #define LTDC_BPCR	0x000C		/* Back Porch Configuration */
65 #define LTDC_AWCR	0x0010		/* Active Width Configuration */
66 #define LTDC_TWCR	0x0014		/* Total Width Configuration */
67 #define LTDC_GCR	0x0018		/* Global Control */
68 #define LTDC_GC1R	0x001C		/* Global Configuration 1 */
69 #define LTDC_GC2R	0x0020		/* Global Configuration 2 */
70 #define LTDC_SRCR	0x0024		/* Shadow Reload Configuration */
71 #define LTDC_GACR	0x0028		/* GAmma Correction */
72 #define LTDC_BCCR	0x002C		/* Background Color Configuration */
73 #define LTDC_IER	0x0034		/* Interrupt Enable */
74 #define LTDC_ISR	0x0038		/* Interrupt Status */
75 #define LTDC_ICR	0x003C		/* Interrupt Clear */
76 #define LTDC_LIPCR	0x0040		/* Line Interrupt Position Conf. */
77 #define LTDC_CPSR	0x0044		/* Current Position Status */
78 #define LTDC_CDSR	0x0048		/* Current Display Status */
79 
80 /* Layer register offsets */
81 #define LTDC_L1LC1R	(0x80)		/* L1 Layer Configuration 1 */
82 #define LTDC_L1LC2R	(0x84)		/* L1 Layer Configuration 2 */
83 #define LTDC_L1CR	(0x84 + REG_OFS)/* L1 Control */
84 #define LTDC_L1WHPCR	(0x88 + REG_OFS)/* L1 Window Hor Position Config */
85 #define LTDC_L1WVPCR	(0x8C + REG_OFS)/* L1 Window Vert Position Config */
86 #define LTDC_L1CKCR	(0x90 + REG_OFS)/* L1 Color Keying Configuration */
87 #define LTDC_L1PFCR	(0x94 + REG_OFS)/* L1 Pixel Format Configuration */
88 #define LTDC_L1CACR	(0x98 + REG_OFS)/* L1 Constant Alpha Config */
89 #define LTDC_L1DCCR	(0x9C + REG_OFS)/* L1 Default Color Configuration */
90 #define LTDC_L1BFCR	(0xA0 + REG_OFS)/* L1 Blend Factors Configuration */
91 #define LTDC_L1FBBCR	(0xA4 + REG_OFS)/* L1 FrameBuffer Bus Control */
92 #define LTDC_L1AFBCR	(0xA8 + REG_OFS)/* L1 AuxFB Control */
93 #define LTDC_L1CFBAR	(0xAC + REG_OFS)/* L1 Color FrameBuffer Address */
94 #define LTDC_L1CFBLR	(0xB0 + REG_OFS)/* L1 Color FrameBuffer Length */
95 #define LTDC_L1CFBLNR	(0xB4 + REG_OFS)/* L1 Color FrameBuffer Line Nb */
96 #define LTDC_L1AFBAR	(0xB8 + REG_OFS)/* L1 AuxFB Address */
97 #define LTDC_L1AFBLR	(0xBC + REG_OFS)/* L1 AuxFB Length */
98 #define LTDC_L1AFBLNR	(0xC0 + REG_OFS)/* L1 AuxFB Line Number */
99 #define LTDC_L1CLUTWR	(0xC4 + REG_OFS)/* L1 CLUT Write */
100 #define LTDC_L1YS1R	(0xE0 + REG_OFS)/* L1 YCbCr Scale 1 */
101 #define LTDC_L1YS2R	(0xE4 + REG_OFS)/* L1 YCbCr Scale 2 */
102 
103 /* Bit definitions */
104 #define SSCR_VSH	GENMASK(10, 0)	/* Vertical Synchronization Height */
105 #define SSCR_HSW	GENMASK(27, 16)	/* Horizontal Synchronization Width */
106 
107 #define BPCR_AVBP	GENMASK(10, 0)	/* Accumulated Vertical Back Porch */
108 #define BPCR_AHBP	GENMASK(27, 16)	/* Accumulated Horizontal Back Porch */
109 
110 #define AWCR_AAH	GENMASK(10, 0)	/* Accumulated Active Height */
111 #define AWCR_AAW	GENMASK(27, 16)	/* Accumulated Active Width */
112 
113 #define TWCR_TOTALH	GENMASK(10, 0)	/* TOTAL Height */
114 #define TWCR_TOTALW	GENMASK(27, 16)	/* TOTAL Width */
115 
116 #define GCR_LTDCEN	BIT(0)		/* LTDC ENable */
117 #define GCR_DEN		BIT(16)		/* Dither ENable */
118 #define GCR_PCPOL	BIT(28)		/* Pixel Clock POLarity-Inverted */
119 #define GCR_DEPOL	BIT(29)		/* Data Enable POLarity-High */
120 #define GCR_VSPOL	BIT(30)		/* Vertical Synchro POLarity-High */
121 #define GCR_HSPOL	BIT(31)		/* Horizontal Synchro POLarity-High */
122 
123 #define GC1R_WBCH	GENMASK(3, 0)	/* Width of Blue CHannel output */
124 #define GC1R_WGCH	GENMASK(7, 4)	/* Width of Green Channel output */
125 #define GC1R_WRCH	GENMASK(11, 8)	/* Width of Red Channel output */
126 #define GC1R_PBEN	BIT(12)		/* Precise Blending ENable */
127 #define GC1R_DT		GENMASK(15, 14)	/* Dithering Technique */
128 #define GC1R_GCT	GENMASK(19, 17)	/* Gamma Correction Technique */
129 #define GC1R_SHREN	BIT(21)		/* SHadow Registers ENabled */
130 #define GC1R_BCP	BIT(22)		/* Background Colour Programmable */
131 #define GC1R_BBEN	BIT(23)		/* Background Blending ENabled */
132 #define GC1R_LNIP	BIT(24)		/* Line Number IRQ Position */
133 #define GC1R_TP		BIT(25)		/* Timing Programmable */
134 #define GC1R_IPP	BIT(26)		/* IRQ Polarity Programmable */
135 #define GC1R_SPP	BIT(27)		/* Sync Polarity Programmable */
136 #define GC1R_DWP	BIT(28)		/* Dither Width Programmable */
137 #define GC1R_STREN	BIT(29)		/* STatus Registers ENabled */
138 #define GC1R_BMEN	BIT(31)		/* Blind Mode ENabled */
139 
140 #define GC2R_EDCA	BIT(0)		/* External Display Control Ability  */
141 #define GC2R_STSAEN	BIT(1)		/* Slave Timing Sync Ability ENabled */
142 #define GC2R_DVAEN	BIT(2)		/* Dual-View Ability ENabled */
143 #define GC2R_DPAEN	BIT(3)		/* Dual-Port Ability ENabled */
144 #define GC2R_BW		GENMASK(6, 4)	/* Bus Width (log2 of nb of bytes) */
145 #define GC2R_EDCEN	BIT(7)		/* External Display Control ENabled */
146 
147 #define SRCR_IMR	BIT(0)		/* IMmediate Reload */
148 #define SRCR_VBR	BIT(1)		/* Vertical Blanking Reload */
149 
150 #define BCCR_BCBLACK	0x00		/* Background Color BLACK */
151 #define BCCR_BCBLUE	GENMASK(7, 0)	/* Background Color BLUE */
152 #define BCCR_BCGREEN	GENMASK(15, 8)	/* Background Color GREEN */
153 #define BCCR_BCRED	GENMASK(23, 16)	/* Background Color RED */
154 #define BCCR_BCWHITE	GENMASK(23, 0)	/* Background Color WHITE */
155 
156 #define IER_LIE		BIT(0)		/* Line Interrupt Enable */
157 #define IER_FUIE	BIT(1)		/* Fifo Underrun Interrupt Enable */
158 #define IER_TERRIE	BIT(2)		/* Transfer ERRor Interrupt Enable */
159 #define IER_RRIE	BIT(3)		/* Register Reload Interrupt enable */
160 
161 #define CPSR_CYPOS	GENMASK(15, 0)	/* Current Y position */
162 
163 #define ISR_LIF		BIT(0)		/* Line Interrupt Flag */
164 #define ISR_FUIF	BIT(1)		/* Fifo Underrun Interrupt Flag */
165 #define ISR_TERRIF	BIT(2)		/* Transfer ERRor Interrupt Flag */
166 #define ISR_RRIF	BIT(3)		/* Register Reload Interrupt Flag */
167 
168 #define LXCR_LEN	BIT(0)		/* Layer ENable */
169 #define LXCR_COLKEN	BIT(1)		/* Color Keying Enable */
170 #define LXCR_CLUTEN	BIT(4)		/* Color Look-Up Table ENable */
171 
172 #define LXWHPCR_WHSTPOS	GENMASK(11, 0)	/* Window Horizontal StarT POSition */
173 #define LXWHPCR_WHSPPOS	GENMASK(27, 16)	/* Window Horizontal StoP POSition */
174 
175 #define LXWVPCR_WVSTPOS	GENMASK(10, 0)	/* Window Vertical StarT POSition */
176 #define LXWVPCR_WVSPPOS	GENMASK(26, 16)	/* Window Vertical StoP POSition */
177 
178 #define LXPFCR_PF	GENMASK(2, 0)	/* Pixel Format */
179 
180 #define LXCACR_CONSTA	GENMASK(7, 0)	/* CONSTant Alpha */
181 
182 #define LXBFCR_BF2	GENMASK(2, 0)	/* Blending Factor 2 */
183 #define LXBFCR_BF1	GENMASK(10, 8)	/* Blending Factor 1 */
184 
185 #define LXCFBLR_CFBLL	GENMASK(12, 0)	/* Color Frame Buffer Line Length */
186 #define LXCFBLR_CFBP	GENMASK(28, 16)	/* Color Frame Buffer Pitch in bytes */
187 
188 #define LXCFBLNR_CFBLN	GENMASK(10, 0)	/* Color Frame Buffer Line Number */
189 
190 #define CLUT_SIZE	256
191 
192 #define CONSTA_MAX	0xFF		/* CONSTant Alpha MAX= 1.0 */
193 #define BF1_PAXCA	0x600		/* Pixel Alpha x Constant Alpha */
194 #define BF1_CA		0x400		/* Constant Alpha */
195 #define BF2_1PAXCA	0x007		/* 1 - (Pixel Alpha x Constant Alpha) */
196 #define BF2_1CA		0x005		/* 1 - Constant Alpha */
197 
198 #define NB_PF		8		/* Max nb of HW pixel format */
199 
200 enum ltdc_pix_fmt {
201 	PF_NONE,
202 	/* RGB formats */
203 	PF_ARGB8888,		/* ARGB [32 bits] */
204 	PF_RGBA8888,		/* RGBA [32 bits] */
205 	PF_RGB888,		/* RGB [24 bits] */
206 	PF_RGB565,		/* RGB [16 bits] */
207 	PF_ARGB1555,		/* ARGB A:1 bit RGB:15 bits [16 bits] */
208 	PF_ARGB4444,		/* ARGB A:4 bits R/G/B: 4 bits each [16 bits] */
209 	/* Indexed formats */
210 	PF_L8,			/* Indexed 8 bits [8 bits] */
211 	PF_AL44,		/* Alpha:4 bits + indexed 4 bits [8 bits] */
212 	PF_AL88			/* Alpha:8 bits + indexed 8 bits [16 bits] */
213 };
214 
215 /* The index gives the encoding of the pixel format for an HW version */
216 static const enum ltdc_pix_fmt ltdc_pix_fmt_a0[NB_PF] = {
217 	PF_ARGB8888,		/* 0x00 */
218 	PF_RGB888,		/* 0x01 */
219 	PF_RGB565,		/* 0x02 */
220 	PF_ARGB1555,		/* 0x03 */
221 	PF_ARGB4444,		/* 0x04 */
222 	PF_L8,			/* 0x05 */
223 	PF_AL44,		/* 0x06 */
224 	PF_AL88			/* 0x07 */
225 };
226 
227 static const enum ltdc_pix_fmt ltdc_pix_fmt_a1[NB_PF] = {
228 	PF_ARGB8888,		/* 0x00 */
229 	PF_RGB888,		/* 0x01 */
230 	PF_RGB565,		/* 0x02 */
231 	PF_RGBA8888,		/* 0x03 */
232 	PF_AL44,		/* 0x04 */
233 	PF_L8,			/* 0x05 */
234 	PF_ARGB1555,		/* 0x06 */
235 	PF_ARGB4444		/* 0x07 */
236 };
237 
238 static const u64 ltdc_format_modifiers[] = {
239 	DRM_FORMAT_MOD_LINEAR,
240 	DRM_FORMAT_MOD_INVALID
241 };
242 
243 static inline u32 reg_read(void __iomem *base, u32 reg)
244 {
245 	return readl_relaxed(base + reg);
246 }
247 
248 static inline void reg_write(void __iomem *base, u32 reg, u32 val)
249 {
250 	writel_relaxed(val, base + reg);
251 }
252 
253 static inline void reg_set(void __iomem *base, u32 reg, u32 mask)
254 {
255 	reg_write(base, reg, reg_read(base, reg) | mask);
256 }
257 
258 static inline void reg_clear(void __iomem *base, u32 reg, u32 mask)
259 {
260 	reg_write(base, reg, reg_read(base, reg) & ~mask);
261 }
262 
263 static inline void reg_update_bits(void __iomem *base, u32 reg, u32 mask,
264 				   u32 val)
265 {
266 	reg_write(base, reg, (reg_read(base, reg) & ~mask) | val);
267 }
268 
269 static inline struct ltdc_device *crtc_to_ltdc(struct drm_crtc *crtc)
270 {
271 	return (struct ltdc_device *)crtc->dev->dev_private;
272 }
273 
274 static inline struct ltdc_device *plane_to_ltdc(struct drm_plane *plane)
275 {
276 	return (struct ltdc_device *)plane->dev->dev_private;
277 }
278 
279 static inline struct ltdc_device *encoder_to_ltdc(struct drm_encoder *enc)
280 {
281 	return (struct ltdc_device *)enc->dev->dev_private;
282 }
283 
284 static inline enum ltdc_pix_fmt to_ltdc_pixelformat(u32 drm_fmt)
285 {
286 	enum ltdc_pix_fmt pf;
287 
288 	switch (drm_fmt) {
289 	case DRM_FORMAT_ARGB8888:
290 	case DRM_FORMAT_XRGB8888:
291 		pf = PF_ARGB8888;
292 		break;
293 	case DRM_FORMAT_RGBA8888:
294 	case DRM_FORMAT_RGBX8888:
295 		pf = PF_RGBA8888;
296 		break;
297 	case DRM_FORMAT_RGB888:
298 		pf = PF_RGB888;
299 		break;
300 	case DRM_FORMAT_RGB565:
301 		pf = PF_RGB565;
302 		break;
303 	case DRM_FORMAT_ARGB1555:
304 	case DRM_FORMAT_XRGB1555:
305 		pf = PF_ARGB1555;
306 		break;
307 	case DRM_FORMAT_ARGB4444:
308 	case DRM_FORMAT_XRGB4444:
309 		pf = PF_ARGB4444;
310 		break;
311 	case DRM_FORMAT_C8:
312 		pf = PF_L8;
313 		break;
314 	default:
315 		pf = PF_NONE;
316 		break;
317 		/* Note: There are no DRM_FORMAT for AL44 and AL88 */
318 	}
319 
320 	return pf;
321 }
322 
323 static inline u32 to_drm_pixelformat(enum ltdc_pix_fmt pf)
324 {
325 	switch (pf) {
326 	case PF_ARGB8888:
327 		return DRM_FORMAT_ARGB8888;
328 	case PF_RGBA8888:
329 		return DRM_FORMAT_RGBA8888;
330 	case PF_RGB888:
331 		return DRM_FORMAT_RGB888;
332 	case PF_RGB565:
333 		return DRM_FORMAT_RGB565;
334 	case PF_ARGB1555:
335 		return DRM_FORMAT_ARGB1555;
336 	case PF_ARGB4444:
337 		return DRM_FORMAT_ARGB4444;
338 	case PF_L8:
339 		return DRM_FORMAT_C8;
340 	case PF_AL44:		/* No DRM support */
341 	case PF_AL88:		/* No DRM support */
342 	case PF_NONE:
343 	default:
344 		return 0;
345 	}
346 }
347 
348 static inline u32 get_pixelformat_without_alpha(u32 drm)
349 {
350 	switch (drm) {
351 	case DRM_FORMAT_ARGB4444:
352 		return DRM_FORMAT_XRGB4444;
353 	case DRM_FORMAT_RGBA4444:
354 		return DRM_FORMAT_RGBX4444;
355 	case DRM_FORMAT_ARGB1555:
356 		return DRM_FORMAT_XRGB1555;
357 	case DRM_FORMAT_RGBA5551:
358 		return DRM_FORMAT_RGBX5551;
359 	case DRM_FORMAT_ARGB8888:
360 		return DRM_FORMAT_XRGB8888;
361 	case DRM_FORMAT_RGBA8888:
362 		return DRM_FORMAT_RGBX8888;
363 	default:
364 		return 0;
365 	}
366 }
367 
368 static irqreturn_t ltdc_irq_thread(int irq, void *arg)
369 {
370 	struct drm_device *ddev = arg;
371 	struct ltdc_device *ldev = ddev->dev_private;
372 	struct drm_crtc *crtc = drm_crtc_from_index(ddev, 0);
373 
374 	/* Line IRQ : trigger the vblank event */
375 	if (ldev->irq_status & ISR_LIF)
376 		drm_crtc_handle_vblank(crtc);
377 
378 	/* Save FIFO Underrun & Transfer Error status */
379 	mutex_lock(&ldev->err_lock);
380 	if (ldev->irq_status & ISR_FUIF)
381 		ldev->error_status |= ISR_FUIF;
382 	if (ldev->irq_status & ISR_TERRIF)
383 		ldev->error_status |= ISR_TERRIF;
384 	mutex_unlock(&ldev->err_lock);
385 
386 	return IRQ_HANDLED;
387 }
388 
389 static irqreturn_t ltdc_irq(int irq, void *arg)
390 {
391 	struct drm_device *ddev = arg;
392 	struct ltdc_device *ldev = ddev->dev_private;
393 
394 	/* Read & Clear the interrupt status */
395 	ldev->irq_status = reg_read(ldev->regs, LTDC_ISR);
396 	reg_write(ldev->regs, LTDC_ICR, ldev->irq_status);
397 
398 	return IRQ_WAKE_THREAD;
399 }
400 
401 /*
402  * DRM_CRTC
403  */
404 
405 static void ltdc_crtc_update_clut(struct drm_crtc *crtc)
406 {
407 	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
408 	struct drm_color_lut *lut;
409 	u32 val;
410 	int i;
411 
412 	if (!crtc->state->color_mgmt_changed || !crtc->state->gamma_lut)
413 		return;
414 
415 	lut = (struct drm_color_lut *)crtc->state->gamma_lut->data;
416 
417 	for (i = 0; i < CLUT_SIZE; i++, lut++) {
418 		val = ((lut->red << 8) & 0xff0000) | (lut->green & 0xff00) |
419 			(lut->blue >> 8) | (i << 24);
420 		reg_write(ldev->regs, LTDC_L1CLUTWR, val);
421 	}
422 }
423 
424 static void ltdc_crtc_atomic_enable(struct drm_crtc *crtc,
425 				    struct drm_crtc_state *old_state)
426 {
427 	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
428 
429 	DRM_DEBUG_DRIVER("\n");
430 
431 	/* Sets the background color value */
432 	reg_write(ldev->regs, LTDC_BCCR, BCCR_BCBLACK);
433 
434 	/* Enable IRQ */
435 	reg_set(ldev->regs, LTDC_IER, IER_RRIE | IER_FUIE | IER_TERRIE);
436 
437 	/* Commit shadow registers = update planes at next vblank */
438 	reg_set(ldev->regs, LTDC_SRCR, SRCR_VBR);
439 
440 	/* Enable LTDC */
441 	reg_set(ldev->regs, LTDC_GCR, GCR_LTDCEN);
442 
443 	drm_crtc_vblank_on(crtc);
444 }
445 
446 static void ltdc_crtc_atomic_disable(struct drm_crtc *crtc,
447 				     struct drm_crtc_state *old_state)
448 {
449 	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
450 	struct drm_device *ddev = crtc->dev;
451 
452 	DRM_DEBUG_DRIVER("\n");
453 
454 	drm_crtc_vblank_off(crtc);
455 
456 	/* disable LTDC */
457 	reg_clear(ldev->regs, LTDC_GCR, GCR_LTDCEN);
458 
459 	/* disable IRQ */
460 	reg_clear(ldev->regs, LTDC_IER, IER_RRIE | IER_FUIE | IER_TERRIE);
461 
462 	/* immediately commit disable of layers before switching off LTDC */
463 	reg_set(ldev->regs, LTDC_SRCR, SRCR_IMR);
464 
465 	pm_runtime_put_sync(ddev->dev);
466 }
467 
468 #define CLK_TOLERANCE_HZ 50
469 
470 static enum drm_mode_status
471 ltdc_crtc_mode_valid(struct drm_crtc *crtc,
472 		     const struct drm_display_mode *mode)
473 {
474 	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
475 	int target = mode->clock * 1000;
476 	int target_min = target - CLK_TOLERANCE_HZ;
477 	int target_max = target + CLK_TOLERANCE_HZ;
478 	int result;
479 
480 	result = clk_round_rate(ldev->pixel_clk, target);
481 
482 	DRM_DEBUG_DRIVER("clk rate target %d, available %d\n", target, result);
483 
484 	/* Filter modes according to the max frequency supported by the pads */
485 	if (result > ldev->caps.pad_max_freq_hz)
486 		return MODE_CLOCK_HIGH;
487 
488 	/*
489 	 * Accept all "preferred" modes:
490 	 * - this is important for panels because panel clock tolerances are
491 	 *   bigger than hdmi ones and there is no reason to not accept them
492 	 *   (the fps may vary a little but it is not a problem).
493 	 * - the hdmi preferred mode will be accepted too, but userland will
494 	 *   be able to use others hdmi "valid" modes if necessary.
495 	 */
496 	if (mode->type & DRM_MODE_TYPE_PREFERRED)
497 		return MODE_OK;
498 
499 	/*
500 	 * Filter modes according to the clock value, particularly useful for
501 	 * hdmi modes that require precise pixel clocks.
502 	 */
503 	if (result < target_min || result > target_max)
504 		return MODE_CLOCK_RANGE;
505 
506 	return MODE_OK;
507 }
508 
509 static bool ltdc_crtc_mode_fixup(struct drm_crtc *crtc,
510 				 const struct drm_display_mode *mode,
511 				 struct drm_display_mode *adjusted_mode)
512 {
513 	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
514 	struct drm_device *ddev = crtc->dev;
515 	int rate = mode->clock * 1000;
516 	bool runtime_active;
517 	int ret;
518 
519 	runtime_active = pm_runtime_active(ddev->dev);
520 
521 	if (runtime_active)
522 		pm_runtime_put_sync(ddev->dev);
523 
524 	if (clk_set_rate(ldev->pixel_clk, rate) < 0) {
525 		DRM_ERROR("Cannot set rate (%dHz) for pixel clk\n", rate);
526 		return false;
527 	}
528 
529 	adjusted_mode->clock = clk_get_rate(ldev->pixel_clk) / 1000;
530 
531 	if (runtime_active) {
532 		ret = pm_runtime_get_sync(ddev->dev);
533 		if (ret) {
534 			DRM_ERROR("Failed to fixup mode, cannot get sync\n");
535 			return false;
536 		}
537 	}
538 
539 	DRM_DEBUG_DRIVER("requested clock %dkHz, adjusted clock %dkHz\n",
540 			 mode->clock, adjusted_mode->clock);
541 
542 	return true;
543 }
544 
545 static void ltdc_crtc_mode_set_nofb(struct drm_crtc *crtc)
546 {
547 	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
548 	struct drm_device *ddev = crtc->dev;
549 	struct drm_display_mode *mode = &crtc->state->adjusted_mode;
550 	struct videomode vm;
551 	u32 hsync, vsync, accum_hbp, accum_vbp, accum_act_w, accum_act_h;
552 	u32 total_width, total_height;
553 	u32 val;
554 	int ret;
555 
556 	if (!pm_runtime_active(ddev->dev)) {
557 		ret = pm_runtime_get_sync(ddev->dev);
558 		if (ret) {
559 			DRM_ERROR("Failed to set mode, cannot get sync\n");
560 			return;
561 		}
562 	}
563 
564 	drm_display_mode_to_videomode(mode, &vm);
565 
566 	DRM_DEBUG_DRIVER("CRTC:%d mode:%s\n", crtc->base.id, mode->name);
567 	DRM_DEBUG_DRIVER("Video mode: %dx%d", vm.hactive, vm.vactive);
568 	DRM_DEBUG_DRIVER(" hfp %d hbp %d hsl %d vfp %d vbp %d vsl %d\n",
569 			 vm.hfront_porch, vm.hback_porch, vm.hsync_len,
570 			 vm.vfront_porch, vm.vback_porch, vm.vsync_len);
571 
572 	/* Convert video timings to ltdc timings */
573 	hsync = vm.hsync_len - 1;
574 	vsync = vm.vsync_len - 1;
575 	accum_hbp = hsync + vm.hback_porch;
576 	accum_vbp = vsync + vm.vback_porch;
577 	accum_act_w = accum_hbp + vm.hactive;
578 	accum_act_h = accum_vbp + vm.vactive;
579 	total_width = accum_act_w + vm.hfront_porch;
580 	total_height = accum_act_h + vm.vfront_porch;
581 
582 	/* Configures the HS, VS, DE and PC polarities. Default Active Low */
583 	val = 0;
584 
585 	if (vm.flags & DISPLAY_FLAGS_HSYNC_HIGH)
586 		val |= GCR_HSPOL;
587 
588 	if (vm.flags & DISPLAY_FLAGS_VSYNC_HIGH)
589 		val |= GCR_VSPOL;
590 
591 	if (vm.flags & DISPLAY_FLAGS_DE_LOW)
592 		val |= GCR_DEPOL;
593 
594 	if (vm.flags & DISPLAY_FLAGS_PIXDATA_NEGEDGE)
595 		val |= GCR_PCPOL;
596 
597 	reg_update_bits(ldev->regs, LTDC_GCR,
598 			GCR_HSPOL | GCR_VSPOL | GCR_DEPOL | GCR_PCPOL, val);
599 
600 	/* Set Synchronization size */
601 	val = (hsync << 16) | vsync;
602 	reg_update_bits(ldev->regs, LTDC_SSCR, SSCR_VSH | SSCR_HSW, val);
603 
604 	/* Set Accumulated Back porch */
605 	val = (accum_hbp << 16) | accum_vbp;
606 	reg_update_bits(ldev->regs, LTDC_BPCR, BPCR_AVBP | BPCR_AHBP, val);
607 
608 	/* Set Accumulated Active Width */
609 	val = (accum_act_w << 16) | accum_act_h;
610 	reg_update_bits(ldev->regs, LTDC_AWCR, AWCR_AAW | AWCR_AAH, val);
611 
612 	/* Set total width & height */
613 	val = (total_width << 16) | total_height;
614 	reg_update_bits(ldev->regs, LTDC_TWCR, TWCR_TOTALH | TWCR_TOTALW, val);
615 
616 	reg_write(ldev->regs, LTDC_LIPCR, (accum_act_h + 1));
617 }
618 
619 static void ltdc_crtc_atomic_flush(struct drm_crtc *crtc,
620 				   struct drm_crtc_state *old_crtc_state)
621 {
622 	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
623 	struct drm_device *ddev = crtc->dev;
624 	struct drm_pending_vblank_event *event = crtc->state->event;
625 
626 	DRM_DEBUG_ATOMIC("\n");
627 
628 	ltdc_crtc_update_clut(crtc);
629 
630 	/* Commit shadow registers = update planes at next vblank */
631 	reg_set(ldev->regs, LTDC_SRCR, SRCR_VBR);
632 
633 	if (event) {
634 		crtc->state->event = NULL;
635 
636 		spin_lock_irq(&ddev->event_lock);
637 		if (drm_crtc_vblank_get(crtc) == 0)
638 			drm_crtc_arm_vblank_event(crtc, event);
639 		else
640 			drm_crtc_send_vblank_event(crtc, event);
641 		spin_unlock_irq(&ddev->event_lock);
642 	}
643 }
644 
645 static const struct drm_crtc_helper_funcs ltdc_crtc_helper_funcs = {
646 	.mode_valid = ltdc_crtc_mode_valid,
647 	.mode_fixup = ltdc_crtc_mode_fixup,
648 	.mode_set_nofb = ltdc_crtc_mode_set_nofb,
649 	.atomic_flush = ltdc_crtc_atomic_flush,
650 	.atomic_enable = ltdc_crtc_atomic_enable,
651 	.atomic_disable = ltdc_crtc_atomic_disable,
652 };
653 
654 static int ltdc_crtc_enable_vblank(struct drm_crtc *crtc)
655 {
656 	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
657 
658 	DRM_DEBUG_DRIVER("\n");
659 	reg_set(ldev->regs, LTDC_IER, IER_LIE);
660 
661 	return 0;
662 }
663 
664 static void ltdc_crtc_disable_vblank(struct drm_crtc *crtc)
665 {
666 	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
667 
668 	DRM_DEBUG_DRIVER("\n");
669 	reg_clear(ldev->regs, LTDC_IER, IER_LIE);
670 }
671 
672 bool ltdc_crtc_scanoutpos(struct drm_device *ddev, unsigned int pipe,
673 			  bool in_vblank_irq, int *vpos, int *hpos,
674 			  ktime_t *stime, ktime_t *etime,
675 			  const struct drm_display_mode *mode)
676 {
677 	struct ltdc_device *ldev = ddev->dev_private;
678 	int line, vactive_start, vactive_end, vtotal;
679 
680 	if (stime)
681 		*stime = ktime_get();
682 
683 	/* The active area starts after vsync + front porch and ends
684 	 * at vsync + front porc + display size.
685 	 * The total height also include back porch.
686 	 * We have 3 possible cases to handle:
687 	 * - line < vactive_start: vpos = line - vactive_start and will be
688 	 * negative
689 	 * - vactive_start < line < vactive_end: vpos = line - vactive_start
690 	 * and will be positive
691 	 * - line > vactive_end: vpos = line - vtotal - vactive_start
692 	 * and will negative
693 	 *
694 	 * Computation for the two first cases are identical so we can
695 	 * simplify the code and only test if line > vactive_end
696 	 */
697 	if (pm_runtime_active(ddev->dev)) {
698 		line = reg_read(ldev->regs, LTDC_CPSR) & CPSR_CYPOS;
699 		vactive_start = reg_read(ldev->regs, LTDC_BPCR) & BPCR_AVBP;
700 		vactive_end = reg_read(ldev->regs, LTDC_AWCR) & AWCR_AAH;
701 		vtotal = reg_read(ldev->regs, LTDC_TWCR) & TWCR_TOTALH;
702 
703 		if (line > vactive_end)
704 			*vpos = line - vtotal - vactive_start;
705 		else
706 			*vpos = line - vactive_start;
707 	} else {
708 		*vpos = 0;
709 	}
710 
711 	*hpos = 0;
712 
713 	if (etime)
714 		*etime = ktime_get();
715 
716 	return true;
717 }
718 
719 static const struct drm_crtc_funcs ltdc_crtc_funcs = {
720 	.destroy = drm_crtc_cleanup,
721 	.set_config = drm_atomic_helper_set_config,
722 	.page_flip = drm_atomic_helper_page_flip,
723 	.reset = drm_atomic_helper_crtc_reset,
724 	.atomic_duplicate_state = drm_atomic_helper_crtc_duplicate_state,
725 	.atomic_destroy_state = drm_atomic_helper_crtc_destroy_state,
726 	.enable_vblank = ltdc_crtc_enable_vblank,
727 	.disable_vblank = ltdc_crtc_disable_vblank,
728 	.gamma_set = drm_atomic_helper_legacy_gamma_set,
729 };
730 
731 /*
732  * DRM_PLANE
733  */
734 
735 static int ltdc_plane_atomic_check(struct drm_plane *plane,
736 				   struct drm_plane_state *state)
737 {
738 	struct drm_framebuffer *fb = state->fb;
739 	u32 src_w, src_h;
740 
741 	DRM_DEBUG_DRIVER("\n");
742 
743 	if (!fb)
744 		return 0;
745 
746 	/* convert src_ from 16:16 format */
747 	src_w = state->src_w >> 16;
748 	src_h = state->src_h >> 16;
749 
750 	/* Reject scaling */
751 	if (src_w != state->crtc_w || src_h != state->crtc_h) {
752 		DRM_ERROR("Scaling is not supported");
753 		return -EINVAL;
754 	}
755 
756 	return 0;
757 }
758 
759 static void ltdc_plane_atomic_update(struct drm_plane *plane,
760 				     struct drm_plane_state *oldstate)
761 {
762 	struct ltdc_device *ldev = plane_to_ltdc(plane);
763 	struct drm_plane_state *state = plane->state;
764 	struct drm_framebuffer *fb = state->fb;
765 	u32 lofs = plane->index * LAY_OFS;
766 	u32 x0 = state->crtc_x;
767 	u32 x1 = state->crtc_x + state->crtc_w - 1;
768 	u32 y0 = state->crtc_y;
769 	u32 y1 = state->crtc_y + state->crtc_h - 1;
770 	u32 src_x, src_y, src_w, src_h;
771 	u32 val, pitch_in_bytes, line_length, paddr, ahbp, avbp, bpcr;
772 	enum ltdc_pix_fmt pf;
773 
774 	if (!state->crtc || !fb) {
775 		DRM_DEBUG_DRIVER("fb or crtc NULL");
776 		return;
777 	}
778 
779 	/* convert src_ from 16:16 format */
780 	src_x = state->src_x >> 16;
781 	src_y = state->src_y >> 16;
782 	src_w = state->src_w >> 16;
783 	src_h = state->src_h >> 16;
784 
785 	DRM_DEBUG_DRIVER("plane:%d fb:%d (%dx%d)@(%d,%d) -> (%dx%d)@(%d,%d)\n",
786 			 plane->base.id, fb->base.id,
787 			 src_w, src_h, src_x, src_y,
788 			 state->crtc_w, state->crtc_h,
789 			 state->crtc_x, state->crtc_y);
790 
791 	bpcr = reg_read(ldev->regs, LTDC_BPCR);
792 	ahbp = (bpcr & BPCR_AHBP) >> 16;
793 	avbp = bpcr & BPCR_AVBP;
794 
795 	/* Configures the horizontal start and stop position */
796 	val = ((x1 + 1 + ahbp) << 16) + (x0 + 1 + ahbp);
797 	reg_update_bits(ldev->regs, LTDC_L1WHPCR + lofs,
798 			LXWHPCR_WHSTPOS | LXWHPCR_WHSPPOS, val);
799 
800 	/* Configures the vertical start and stop position */
801 	val = ((y1 + 1 + avbp) << 16) + (y0 + 1 + avbp);
802 	reg_update_bits(ldev->regs, LTDC_L1WVPCR + lofs,
803 			LXWVPCR_WVSTPOS | LXWVPCR_WVSPPOS, val);
804 
805 	/* Specifies the pixel format */
806 	pf = to_ltdc_pixelformat(fb->format->format);
807 	for (val = 0; val < NB_PF; val++)
808 		if (ldev->caps.pix_fmt_hw[val] == pf)
809 			break;
810 
811 	if (val == NB_PF) {
812 		DRM_ERROR("Pixel format %.4s not supported\n",
813 			  (char *)&fb->format->format);
814 		val = 0;	/* set by default ARGB 32 bits */
815 	}
816 	reg_update_bits(ldev->regs, LTDC_L1PFCR + lofs, LXPFCR_PF, val);
817 
818 	/* Configures the color frame buffer pitch in bytes & line length */
819 	pitch_in_bytes = fb->pitches[0];
820 	line_length = fb->format->cpp[0] *
821 		      (x1 - x0 + 1) + (ldev->caps.bus_width >> 3) - 1;
822 	val = ((pitch_in_bytes << 16) | line_length);
823 	reg_update_bits(ldev->regs, LTDC_L1CFBLR + lofs,
824 			LXCFBLR_CFBLL | LXCFBLR_CFBP, val);
825 
826 	/* Specifies the constant alpha value */
827 	val = CONSTA_MAX;
828 	reg_update_bits(ldev->regs, LTDC_L1CACR + lofs, LXCACR_CONSTA, val);
829 
830 	/* Specifies the blending factors */
831 	val = BF1_PAXCA | BF2_1PAXCA;
832 	if (!fb->format->has_alpha)
833 		val = BF1_CA | BF2_1CA;
834 
835 	/* Manage hw-specific capabilities */
836 	if (ldev->caps.non_alpha_only_l1 &&
837 	    plane->type != DRM_PLANE_TYPE_PRIMARY)
838 		val = BF1_PAXCA | BF2_1PAXCA;
839 
840 	reg_update_bits(ldev->regs, LTDC_L1BFCR + lofs,
841 			LXBFCR_BF2 | LXBFCR_BF1, val);
842 
843 	/* Configures the frame buffer line number */
844 	val = y1 - y0 + 1;
845 	reg_update_bits(ldev->regs, LTDC_L1CFBLNR + lofs, LXCFBLNR_CFBLN, val);
846 
847 	/* Sets the FB address */
848 	paddr = (u32)drm_fb_cma_get_gem_addr(fb, state, 0);
849 
850 	DRM_DEBUG_DRIVER("fb: phys 0x%08x", paddr);
851 	reg_write(ldev->regs, LTDC_L1CFBAR + lofs, paddr);
852 
853 	/* Enable layer and CLUT if needed */
854 	val = fb->format->format == DRM_FORMAT_C8 ? LXCR_CLUTEN : 0;
855 	val |= LXCR_LEN;
856 	reg_update_bits(ldev->regs, LTDC_L1CR + lofs,
857 			LXCR_LEN | LXCR_CLUTEN, val);
858 
859 	ldev->plane_fpsi[plane->index].counter++;
860 
861 	mutex_lock(&ldev->err_lock);
862 	if (ldev->error_status & ISR_FUIF) {
863 		DRM_WARN("ltdc fifo underrun: please verify display mode\n");
864 		ldev->error_status &= ~ISR_FUIF;
865 	}
866 	if (ldev->error_status & ISR_TERRIF) {
867 		DRM_WARN("ltdc transfer error\n");
868 		ldev->error_status &= ~ISR_TERRIF;
869 	}
870 	mutex_unlock(&ldev->err_lock);
871 }
872 
873 static void ltdc_plane_atomic_disable(struct drm_plane *plane,
874 				      struct drm_plane_state *oldstate)
875 {
876 	struct ltdc_device *ldev = plane_to_ltdc(plane);
877 	u32 lofs = plane->index * LAY_OFS;
878 
879 	/* disable layer */
880 	reg_clear(ldev->regs, LTDC_L1CR + lofs, LXCR_LEN);
881 
882 	DRM_DEBUG_DRIVER("CRTC:%d plane:%d\n",
883 			 oldstate->crtc->base.id, plane->base.id);
884 }
885 
886 static void ltdc_plane_atomic_print_state(struct drm_printer *p,
887 					  const struct drm_plane_state *state)
888 {
889 	struct drm_plane *plane = state->plane;
890 	struct ltdc_device *ldev = plane_to_ltdc(plane);
891 	struct fps_info *fpsi = &ldev->plane_fpsi[plane->index];
892 	int ms_since_last;
893 	ktime_t now;
894 
895 	now = ktime_get();
896 	ms_since_last = ktime_to_ms(ktime_sub(now, fpsi->last_timestamp));
897 
898 	drm_printf(p, "\tuser_updates=%dfps\n",
899 		   DIV_ROUND_CLOSEST(fpsi->counter * 1000, ms_since_last));
900 
901 	fpsi->last_timestamp = now;
902 	fpsi->counter = 0;
903 }
904 
905 static bool ltdc_plane_format_mod_supported(struct drm_plane *plane,
906 					    u32 format,
907 					    u64 modifier)
908 {
909 	if (modifier == DRM_FORMAT_MOD_LINEAR)
910 		return true;
911 
912 	return false;
913 }
914 
915 static const struct drm_plane_funcs ltdc_plane_funcs = {
916 	.update_plane = drm_atomic_helper_update_plane,
917 	.disable_plane = drm_atomic_helper_disable_plane,
918 	.destroy = drm_plane_cleanup,
919 	.reset = drm_atomic_helper_plane_reset,
920 	.atomic_duplicate_state = drm_atomic_helper_plane_duplicate_state,
921 	.atomic_destroy_state = drm_atomic_helper_plane_destroy_state,
922 	.atomic_print_state = ltdc_plane_atomic_print_state,
923 	.format_mod_supported = ltdc_plane_format_mod_supported,
924 };
925 
926 static const struct drm_plane_helper_funcs ltdc_plane_helper_funcs = {
927 	.prepare_fb = drm_gem_fb_prepare_fb,
928 	.atomic_check = ltdc_plane_atomic_check,
929 	.atomic_update = ltdc_plane_atomic_update,
930 	.atomic_disable = ltdc_plane_atomic_disable,
931 };
932 
933 static struct drm_plane *ltdc_plane_create(struct drm_device *ddev,
934 					   enum drm_plane_type type)
935 {
936 	unsigned long possible_crtcs = CRTC_MASK;
937 	struct ltdc_device *ldev = ddev->dev_private;
938 	struct device *dev = ddev->dev;
939 	struct drm_plane *plane;
940 	unsigned int i, nb_fmt = 0;
941 	u32 formats[NB_PF * 2];
942 	u32 drm_fmt, drm_fmt_no_alpha;
943 	const u64 *modifiers = ltdc_format_modifiers;
944 	int ret;
945 
946 	/* Get supported pixel formats */
947 	for (i = 0; i < NB_PF; i++) {
948 		drm_fmt = to_drm_pixelformat(ldev->caps.pix_fmt_hw[i]);
949 		if (!drm_fmt)
950 			continue;
951 		formats[nb_fmt++] = drm_fmt;
952 
953 		/* Add the no-alpha related format if any & supported */
954 		drm_fmt_no_alpha = get_pixelformat_without_alpha(drm_fmt);
955 		if (!drm_fmt_no_alpha)
956 			continue;
957 
958 		/* Manage hw-specific capabilities */
959 		if (ldev->caps.non_alpha_only_l1 &&
960 		    type != DRM_PLANE_TYPE_PRIMARY)
961 			continue;
962 
963 		formats[nb_fmt++] = drm_fmt_no_alpha;
964 	}
965 
966 	plane = devm_kzalloc(dev, sizeof(*plane), GFP_KERNEL);
967 	if (!plane)
968 		return NULL;
969 
970 	ret = drm_universal_plane_init(ddev, plane, possible_crtcs,
971 				       &ltdc_plane_funcs, formats, nb_fmt,
972 				       modifiers, type, NULL);
973 	if (ret < 0)
974 		return NULL;
975 
976 	drm_plane_helper_add(plane, &ltdc_plane_helper_funcs);
977 
978 	DRM_DEBUG_DRIVER("plane:%d created\n", plane->base.id);
979 
980 	return plane;
981 }
982 
983 static void ltdc_plane_destroy_all(struct drm_device *ddev)
984 {
985 	struct drm_plane *plane, *plane_temp;
986 
987 	list_for_each_entry_safe(plane, plane_temp,
988 				 &ddev->mode_config.plane_list, head)
989 		drm_plane_cleanup(plane);
990 }
991 
992 static int ltdc_crtc_init(struct drm_device *ddev, struct drm_crtc *crtc)
993 {
994 	struct ltdc_device *ldev = ddev->dev_private;
995 	struct drm_plane *primary, *overlay;
996 	unsigned int i;
997 	int ret;
998 
999 	primary = ltdc_plane_create(ddev, DRM_PLANE_TYPE_PRIMARY);
1000 	if (!primary) {
1001 		DRM_ERROR("Can not create primary plane\n");
1002 		return -EINVAL;
1003 	}
1004 
1005 	ret = drm_crtc_init_with_planes(ddev, crtc, primary, NULL,
1006 					&ltdc_crtc_funcs, NULL);
1007 	if (ret) {
1008 		DRM_ERROR("Can not initialize CRTC\n");
1009 		goto cleanup;
1010 	}
1011 
1012 	drm_crtc_helper_add(crtc, &ltdc_crtc_helper_funcs);
1013 
1014 	drm_mode_crtc_set_gamma_size(crtc, CLUT_SIZE);
1015 	drm_crtc_enable_color_mgmt(crtc, 0, false, CLUT_SIZE);
1016 
1017 	DRM_DEBUG_DRIVER("CRTC:%d created\n", crtc->base.id);
1018 
1019 	/* Add planes. Note : the first layer is used by primary plane */
1020 	for (i = 1; i < ldev->caps.nb_layers; i++) {
1021 		overlay = ltdc_plane_create(ddev, DRM_PLANE_TYPE_OVERLAY);
1022 		if (!overlay) {
1023 			ret = -ENOMEM;
1024 			DRM_ERROR("Can not create overlay plane %d\n", i);
1025 			goto cleanup;
1026 		}
1027 	}
1028 
1029 	return 0;
1030 
1031 cleanup:
1032 	ltdc_plane_destroy_all(ddev);
1033 	return ret;
1034 }
1035 
1036 /*
1037  * DRM_ENCODER
1038  */
1039 
1040 static const struct drm_encoder_funcs ltdc_encoder_funcs = {
1041 	.destroy = drm_encoder_cleanup,
1042 };
1043 
1044 static void ltdc_encoder_disable(struct drm_encoder *encoder)
1045 {
1046 	struct drm_device *ddev = encoder->dev;
1047 
1048 	DRM_DEBUG_DRIVER("\n");
1049 
1050 	/* Set to sleep state the pinctrl whatever type of encoder */
1051 	pinctrl_pm_select_sleep_state(ddev->dev);
1052 }
1053 
1054 static void ltdc_encoder_enable(struct drm_encoder *encoder)
1055 {
1056 	struct drm_device *ddev = encoder->dev;
1057 
1058 	DRM_DEBUG_DRIVER("\n");
1059 
1060 	/*
1061 	 * Set to default state the pinctrl only with DPI type.
1062 	 * Others types like DSI, don't need pinctrl due to
1063 	 * internal bridge (the signals do not come out of the chipset).
1064 	 */
1065 	if (encoder->encoder_type == DRM_MODE_ENCODER_DPI)
1066 		pinctrl_pm_select_default_state(ddev->dev);
1067 }
1068 
1069 static const struct drm_encoder_helper_funcs ltdc_encoder_helper_funcs = {
1070 	.disable = ltdc_encoder_disable,
1071 	.enable = ltdc_encoder_enable,
1072 };
1073 
1074 static int ltdc_encoder_init(struct drm_device *ddev, struct drm_bridge *bridge)
1075 {
1076 	struct drm_encoder *encoder;
1077 	int ret;
1078 
1079 	encoder = devm_kzalloc(ddev->dev, sizeof(*encoder), GFP_KERNEL);
1080 	if (!encoder)
1081 		return -ENOMEM;
1082 
1083 	encoder->possible_crtcs = CRTC_MASK;
1084 	encoder->possible_clones = 0;	/* No cloning support */
1085 
1086 	drm_encoder_init(ddev, encoder, &ltdc_encoder_funcs,
1087 			 DRM_MODE_ENCODER_DPI, NULL);
1088 
1089 	drm_encoder_helper_add(encoder, &ltdc_encoder_helper_funcs);
1090 
1091 	ret = drm_bridge_attach(encoder, bridge, NULL);
1092 	if (ret) {
1093 		drm_encoder_cleanup(encoder);
1094 		return -EINVAL;
1095 	}
1096 
1097 	DRM_DEBUG_DRIVER("Bridge encoder:%d created\n", encoder->base.id);
1098 
1099 	return 0;
1100 }
1101 
1102 static int ltdc_get_caps(struct drm_device *ddev)
1103 {
1104 	struct ltdc_device *ldev = ddev->dev_private;
1105 	u32 bus_width_log2, lcr, gc2r;
1106 
1107 	/*
1108 	 * at least 1 layer must be managed & the number of layers
1109 	 * must not exceed LTDC_MAX_LAYER
1110 	 */
1111 	lcr = reg_read(ldev->regs, LTDC_LCR);
1112 
1113 	ldev->caps.nb_layers = clamp((int)lcr, 1, LTDC_MAX_LAYER);
1114 
1115 	/* set data bus width */
1116 	gc2r = reg_read(ldev->regs, LTDC_GC2R);
1117 	bus_width_log2 = (gc2r & GC2R_BW) >> 4;
1118 	ldev->caps.bus_width = 8 << bus_width_log2;
1119 	ldev->caps.hw_version = reg_read(ldev->regs, LTDC_IDR);
1120 
1121 	switch (ldev->caps.hw_version) {
1122 	case HWVER_10200:
1123 	case HWVER_10300:
1124 		ldev->caps.reg_ofs = REG_OFS_NONE;
1125 		ldev->caps.pix_fmt_hw = ltdc_pix_fmt_a0;
1126 		/*
1127 		 * Hw older versions support non-alpha color formats derived
1128 		 * from native alpha color formats only on the primary layer.
1129 		 * For instance, RG16 native format without alpha works fine
1130 		 * on 2nd layer but XR24 (derived color format from AR24)
1131 		 * does not work on 2nd layer.
1132 		 */
1133 		ldev->caps.non_alpha_only_l1 = true;
1134 		ldev->caps.pad_max_freq_hz = 90000000;
1135 		if (ldev->caps.hw_version == HWVER_10200)
1136 			ldev->caps.pad_max_freq_hz = 65000000;
1137 		break;
1138 	case HWVER_20101:
1139 		ldev->caps.reg_ofs = REG_OFS_4;
1140 		ldev->caps.pix_fmt_hw = ltdc_pix_fmt_a1;
1141 		ldev->caps.non_alpha_only_l1 = false;
1142 		ldev->caps.pad_max_freq_hz = 150000000;
1143 		break;
1144 	default:
1145 		return -ENODEV;
1146 	}
1147 
1148 	return 0;
1149 }
1150 
1151 void ltdc_suspend(struct drm_device *ddev)
1152 {
1153 	struct ltdc_device *ldev = ddev->dev_private;
1154 
1155 	DRM_DEBUG_DRIVER("\n");
1156 	clk_disable_unprepare(ldev->pixel_clk);
1157 }
1158 
1159 int ltdc_resume(struct drm_device *ddev)
1160 {
1161 	struct ltdc_device *ldev = ddev->dev_private;
1162 	int ret;
1163 
1164 	DRM_DEBUG_DRIVER("\n");
1165 
1166 	ret = clk_prepare_enable(ldev->pixel_clk);
1167 	if (ret) {
1168 		DRM_ERROR("failed to enable pixel clock (%d)\n", ret);
1169 		return ret;
1170 	}
1171 
1172 	return 0;
1173 }
1174 
1175 int ltdc_load(struct drm_device *ddev)
1176 {
1177 	struct platform_device *pdev = to_platform_device(ddev->dev);
1178 	struct ltdc_device *ldev = ddev->dev_private;
1179 	struct device *dev = ddev->dev;
1180 	struct device_node *np = dev->of_node;
1181 	struct drm_bridge *bridge[MAX_ENDPOINTS] = {NULL};
1182 	struct drm_panel *panel[MAX_ENDPOINTS] = {NULL};
1183 	struct drm_crtc *crtc;
1184 	struct reset_control *rstc;
1185 	struct resource *res;
1186 	int irq, ret, i, endpoint_not_ready = -ENODEV;
1187 
1188 	DRM_DEBUG_DRIVER("\n");
1189 
1190 	/* Get endpoints if any */
1191 	for (i = 0; i < MAX_ENDPOINTS; i++) {
1192 		ret = drm_of_find_panel_or_bridge(np, 0, i, &panel[i],
1193 						  &bridge[i]);
1194 
1195 		/*
1196 		 * If at least one endpoint is -EPROBE_DEFER, defer probing,
1197 		 * else if at least one endpoint is ready, continue probing.
1198 		 */
1199 		if (ret == -EPROBE_DEFER)
1200 			return ret;
1201 		else if (!ret)
1202 			endpoint_not_ready = 0;
1203 	}
1204 
1205 	if (endpoint_not_ready)
1206 		return endpoint_not_ready;
1207 
1208 	rstc = devm_reset_control_get_exclusive(dev, NULL);
1209 
1210 	mutex_init(&ldev->err_lock);
1211 
1212 	ldev->pixel_clk = devm_clk_get(dev, "lcd");
1213 	if (IS_ERR(ldev->pixel_clk)) {
1214 		if (PTR_ERR(ldev->pixel_clk) != -EPROBE_DEFER)
1215 			DRM_ERROR("Unable to get lcd clock\n");
1216 		return PTR_ERR(ldev->pixel_clk);
1217 	}
1218 
1219 	if (clk_prepare_enable(ldev->pixel_clk)) {
1220 		DRM_ERROR("Unable to prepare pixel clock\n");
1221 		return -ENODEV;
1222 	}
1223 
1224 	if (!IS_ERR(rstc)) {
1225 		reset_control_assert(rstc);
1226 		usleep_range(10, 20);
1227 		reset_control_deassert(rstc);
1228 	}
1229 
1230 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1231 	ldev->regs = devm_ioremap_resource(dev, res);
1232 	if (IS_ERR(ldev->regs)) {
1233 		DRM_ERROR("Unable to get ltdc registers\n");
1234 		ret = PTR_ERR(ldev->regs);
1235 		goto err;
1236 	}
1237 
1238 	/* Disable interrupts */
1239 	reg_clear(ldev->regs, LTDC_IER,
1240 		  IER_LIE | IER_RRIE | IER_FUIE | IER_TERRIE);
1241 
1242 	for (i = 0; i < MAX_IRQ; i++) {
1243 		irq = platform_get_irq(pdev, i);
1244 		if (irq == -EPROBE_DEFER)
1245 			goto err;
1246 
1247 		if (irq < 0)
1248 			continue;
1249 
1250 		ret = devm_request_threaded_irq(dev, irq, ltdc_irq,
1251 						ltdc_irq_thread, IRQF_ONESHOT,
1252 						dev_name(dev), ddev);
1253 		if (ret) {
1254 			DRM_ERROR("Failed to register LTDC interrupt\n");
1255 			goto err;
1256 		}
1257 	}
1258 
1259 
1260 	ret = ltdc_get_caps(ddev);
1261 	if (ret) {
1262 		DRM_ERROR("hardware identifier (0x%08x) not supported!\n",
1263 			  ldev->caps.hw_version);
1264 		goto err;
1265 	}
1266 
1267 	DRM_DEBUG_DRIVER("ltdc hw version 0x%08x\n", ldev->caps.hw_version);
1268 
1269 	/* Add endpoints panels or bridges if any */
1270 	for (i = 0; i < MAX_ENDPOINTS; i++) {
1271 		if (panel[i]) {
1272 			bridge[i] = drm_panel_bridge_add_typed(panel[i],
1273 							       DRM_MODE_CONNECTOR_DPI);
1274 			if (IS_ERR(bridge[i])) {
1275 				DRM_ERROR("panel-bridge endpoint %d\n", i);
1276 				ret = PTR_ERR(bridge[i]);
1277 				goto err;
1278 			}
1279 		}
1280 
1281 		if (bridge[i]) {
1282 			ret = ltdc_encoder_init(ddev, bridge[i]);
1283 			if (ret) {
1284 				DRM_ERROR("init encoder endpoint %d\n", i);
1285 				goto err;
1286 			}
1287 		}
1288 	}
1289 
1290 	crtc = devm_kzalloc(dev, sizeof(*crtc), GFP_KERNEL);
1291 	if (!crtc) {
1292 		DRM_ERROR("Failed to allocate crtc\n");
1293 		ret = -ENOMEM;
1294 		goto err;
1295 	}
1296 
1297 	ddev->mode_config.allow_fb_modifiers = true;
1298 
1299 	ret = ltdc_crtc_init(ddev, crtc);
1300 	if (ret) {
1301 		DRM_ERROR("Failed to init crtc\n");
1302 		goto err;
1303 	}
1304 
1305 	ret = drm_vblank_init(ddev, NB_CRTC);
1306 	if (ret) {
1307 		DRM_ERROR("Failed calling drm_vblank_init()\n");
1308 		goto err;
1309 	}
1310 
1311 	/* Allow usage of vblank without having to call drm_irq_install */
1312 	ddev->irq_enabled = 1;
1313 
1314 	clk_disable_unprepare(ldev->pixel_clk);
1315 
1316 	pinctrl_pm_select_sleep_state(ddev->dev);
1317 
1318 	pm_runtime_enable(ddev->dev);
1319 
1320 	return 0;
1321 err:
1322 	for (i = 0; i < MAX_ENDPOINTS; i++)
1323 		drm_panel_bridge_remove(bridge[i]);
1324 
1325 	clk_disable_unprepare(ldev->pixel_clk);
1326 
1327 	return ret;
1328 }
1329 
1330 void ltdc_unload(struct drm_device *ddev)
1331 {
1332 	int i;
1333 
1334 	DRM_DEBUG_DRIVER("\n");
1335 
1336 	for (i = 0; i < MAX_ENDPOINTS; i++)
1337 		drm_of_panel_bridge_remove(ddev->dev->of_node, 0, i);
1338 
1339 	pm_runtime_disable(ddev->dev);
1340 }
1341 
1342 MODULE_AUTHOR("Philippe Cornu <philippe.cornu@st.com>");
1343 MODULE_AUTHOR("Yannick Fertre <yannick.fertre@st.com>");
1344 MODULE_AUTHOR("Fabien Dessenne <fabien.dessenne@st.com>");
1345 MODULE_AUTHOR("Mickael Reulier <mickael.reulier@st.com>");
1346 MODULE_DESCRIPTION("STMicroelectronics ST DRM LTDC driver");
1347 MODULE_LICENSE("GPL v2");
1348