xref: /openbmc/linux/drivers/gpu/drm/stm/ltdc.c (revision 78560d41)
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 	drm_crtc_vblank_on(crtc);
441 }
442 
443 static void ltdc_crtc_atomic_disable(struct drm_crtc *crtc,
444 				     struct drm_crtc_state *old_state)
445 {
446 	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
447 	struct drm_device *ddev = crtc->dev;
448 
449 	DRM_DEBUG_DRIVER("\n");
450 
451 	drm_crtc_vblank_off(crtc);
452 
453 	/* disable IRQ */
454 	reg_clear(ldev->regs, LTDC_IER, IER_RRIE | IER_FUIE | IER_TERRIE);
455 
456 	/* immediately commit disable of layers before switching off LTDC */
457 	reg_set(ldev->regs, LTDC_SRCR, SRCR_IMR);
458 
459 	pm_runtime_put_sync(ddev->dev);
460 }
461 
462 #define CLK_TOLERANCE_HZ 50
463 
464 static enum drm_mode_status
465 ltdc_crtc_mode_valid(struct drm_crtc *crtc,
466 		     const struct drm_display_mode *mode)
467 {
468 	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
469 	int target = mode->clock * 1000;
470 	int target_min = target - CLK_TOLERANCE_HZ;
471 	int target_max = target + CLK_TOLERANCE_HZ;
472 	int result;
473 
474 	result = clk_round_rate(ldev->pixel_clk, target);
475 
476 	DRM_DEBUG_DRIVER("clk rate target %d, available %d\n", target, result);
477 
478 	/* Filter modes according to the max frequency supported by the pads */
479 	if (result > ldev->caps.pad_max_freq_hz)
480 		return MODE_CLOCK_HIGH;
481 
482 	/*
483 	 * Accept all "preferred" modes:
484 	 * - this is important for panels because panel clock tolerances are
485 	 *   bigger than hdmi ones and there is no reason to not accept them
486 	 *   (the fps may vary a little but it is not a problem).
487 	 * - the hdmi preferred mode will be accepted too, but userland will
488 	 *   be able to use others hdmi "valid" modes if necessary.
489 	 */
490 	if (mode->type & DRM_MODE_TYPE_PREFERRED)
491 		return MODE_OK;
492 
493 	/*
494 	 * Filter modes according to the clock value, particularly useful for
495 	 * hdmi modes that require precise pixel clocks.
496 	 */
497 	if (result < target_min || result > target_max)
498 		return MODE_CLOCK_RANGE;
499 
500 	return MODE_OK;
501 }
502 
503 static bool ltdc_crtc_mode_fixup(struct drm_crtc *crtc,
504 				 const struct drm_display_mode *mode,
505 				 struct drm_display_mode *adjusted_mode)
506 {
507 	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
508 	struct drm_device *ddev = crtc->dev;
509 	int rate = mode->clock * 1000;
510 	bool runtime_active;
511 	int ret;
512 
513 	runtime_active = pm_runtime_active(ddev->dev);
514 
515 	if (runtime_active)
516 		pm_runtime_put_sync(ddev->dev);
517 
518 	if (clk_set_rate(ldev->pixel_clk, rate) < 0) {
519 		DRM_ERROR("Cannot set rate (%dHz) for pixel clk\n", rate);
520 		return false;
521 	}
522 
523 	adjusted_mode->clock = clk_get_rate(ldev->pixel_clk) / 1000;
524 
525 	if (runtime_active) {
526 		ret = pm_runtime_get_sync(ddev->dev);
527 		if (ret) {
528 			DRM_ERROR("Failed to fixup mode, cannot get sync\n");
529 			return false;
530 		}
531 	}
532 
533 	DRM_DEBUG_DRIVER("requested clock %dkHz, adjusted clock %dkHz\n",
534 			 mode->clock, adjusted_mode->clock);
535 
536 	return true;
537 }
538 
539 static void ltdc_crtc_mode_set_nofb(struct drm_crtc *crtc)
540 {
541 	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
542 	struct drm_device *ddev = crtc->dev;
543 	struct drm_display_mode *mode = &crtc->state->adjusted_mode;
544 	struct videomode vm;
545 	u32 hsync, vsync, accum_hbp, accum_vbp, accum_act_w, accum_act_h;
546 	u32 total_width, total_height;
547 	u32 val;
548 	int ret;
549 
550 	if (!pm_runtime_active(ddev->dev)) {
551 		ret = pm_runtime_get_sync(ddev->dev);
552 		if (ret) {
553 			DRM_ERROR("Failed to set mode, cannot get sync\n");
554 			return;
555 		}
556 	}
557 
558 	drm_display_mode_to_videomode(mode, &vm);
559 
560 	DRM_DEBUG_DRIVER("CRTC:%d mode:%s\n", crtc->base.id, mode->name);
561 	DRM_DEBUG_DRIVER("Video mode: %dx%d", vm.hactive, vm.vactive);
562 	DRM_DEBUG_DRIVER(" hfp %d hbp %d hsl %d vfp %d vbp %d vsl %d\n",
563 			 vm.hfront_porch, vm.hback_porch, vm.hsync_len,
564 			 vm.vfront_porch, vm.vback_porch, vm.vsync_len);
565 
566 	/* Convert video timings to ltdc timings */
567 	hsync = vm.hsync_len - 1;
568 	vsync = vm.vsync_len - 1;
569 	accum_hbp = hsync + vm.hback_porch;
570 	accum_vbp = vsync + vm.vback_porch;
571 	accum_act_w = accum_hbp + vm.hactive;
572 	accum_act_h = accum_vbp + vm.vactive;
573 	total_width = accum_act_w + vm.hfront_porch;
574 	total_height = accum_act_h + vm.vfront_porch;
575 
576 	/* Configures the HS, VS, DE and PC polarities. Default Active Low */
577 	val = 0;
578 
579 	if (vm.flags & DISPLAY_FLAGS_HSYNC_HIGH)
580 		val |= GCR_HSPOL;
581 
582 	if (vm.flags & DISPLAY_FLAGS_VSYNC_HIGH)
583 		val |= GCR_VSPOL;
584 
585 	if (vm.flags & DISPLAY_FLAGS_DE_LOW)
586 		val |= GCR_DEPOL;
587 
588 	if (vm.flags & DISPLAY_FLAGS_PIXDATA_NEGEDGE)
589 		val |= GCR_PCPOL;
590 
591 	reg_update_bits(ldev->regs, LTDC_GCR,
592 			GCR_HSPOL | GCR_VSPOL | GCR_DEPOL | GCR_PCPOL, val);
593 
594 	/* Set Synchronization size */
595 	val = (hsync << 16) | vsync;
596 	reg_update_bits(ldev->regs, LTDC_SSCR, SSCR_VSH | SSCR_HSW, val);
597 
598 	/* Set Accumulated Back porch */
599 	val = (accum_hbp << 16) | accum_vbp;
600 	reg_update_bits(ldev->regs, LTDC_BPCR, BPCR_AVBP | BPCR_AHBP, val);
601 
602 	/* Set Accumulated Active Width */
603 	val = (accum_act_w << 16) | accum_act_h;
604 	reg_update_bits(ldev->regs, LTDC_AWCR, AWCR_AAW | AWCR_AAH, val);
605 
606 	/* Set total width & height */
607 	val = (total_width << 16) | total_height;
608 	reg_update_bits(ldev->regs, LTDC_TWCR, TWCR_TOTALH | TWCR_TOTALW, val);
609 
610 	reg_write(ldev->regs, LTDC_LIPCR, (accum_act_h + 1));
611 }
612 
613 static void ltdc_crtc_atomic_flush(struct drm_crtc *crtc,
614 				   struct drm_crtc_state *old_crtc_state)
615 {
616 	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
617 	struct drm_device *ddev = crtc->dev;
618 	struct drm_pending_vblank_event *event = crtc->state->event;
619 
620 	DRM_DEBUG_ATOMIC("\n");
621 
622 	ltdc_crtc_update_clut(crtc);
623 
624 	/* Commit shadow registers = update planes at next vblank */
625 	reg_set(ldev->regs, LTDC_SRCR, SRCR_VBR);
626 
627 	if (event) {
628 		crtc->state->event = NULL;
629 
630 		spin_lock_irq(&ddev->event_lock);
631 		if (drm_crtc_vblank_get(crtc) == 0)
632 			drm_crtc_arm_vblank_event(crtc, event);
633 		else
634 			drm_crtc_send_vblank_event(crtc, event);
635 		spin_unlock_irq(&ddev->event_lock);
636 	}
637 }
638 
639 static const struct drm_crtc_helper_funcs ltdc_crtc_helper_funcs = {
640 	.mode_valid = ltdc_crtc_mode_valid,
641 	.mode_fixup = ltdc_crtc_mode_fixup,
642 	.mode_set_nofb = ltdc_crtc_mode_set_nofb,
643 	.atomic_flush = ltdc_crtc_atomic_flush,
644 	.atomic_enable = ltdc_crtc_atomic_enable,
645 	.atomic_disable = ltdc_crtc_atomic_disable,
646 };
647 
648 static int ltdc_crtc_enable_vblank(struct drm_crtc *crtc)
649 {
650 	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
651 
652 	DRM_DEBUG_DRIVER("\n");
653 	reg_set(ldev->regs, LTDC_IER, IER_LIE);
654 
655 	return 0;
656 }
657 
658 static void ltdc_crtc_disable_vblank(struct drm_crtc *crtc)
659 {
660 	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
661 
662 	DRM_DEBUG_DRIVER("\n");
663 	reg_clear(ldev->regs, LTDC_IER, IER_LIE);
664 }
665 
666 bool ltdc_crtc_scanoutpos(struct drm_device *ddev, unsigned int pipe,
667 			  bool in_vblank_irq, int *vpos, int *hpos,
668 			  ktime_t *stime, ktime_t *etime,
669 			  const struct drm_display_mode *mode)
670 {
671 	struct ltdc_device *ldev = ddev->dev_private;
672 	int line, vactive_start, vactive_end, vtotal;
673 
674 	if (stime)
675 		*stime = ktime_get();
676 
677 	/* The active area starts after vsync + front porch and ends
678 	 * at vsync + front porc + display size.
679 	 * The total height also include back porch.
680 	 * We have 3 possible cases to handle:
681 	 * - line < vactive_start: vpos = line - vactive_start and will be
682 	 * negative
683 	 * - vactive_start < line < vactive_end: vpos = line - vactive_start
684 	 * and will be positive
685 	 * - line > vactive_end: vpos = line - vtotal - vactive_start
686 	 * and will negative
687 	 *
688 	 * Computation for the two first cases are identical so we can
689 	 * simplify the code and only test if line > vactive_end
690 	 */
691 	if (pm_runtime_active(ddev->dev)) {
692 		line = reg_read(ldev->regs, LTDC_CPSR) & CPSR_CYPOS;
693 		vactive_start = reg_read(ldev->regs, LTDC_BPCR) & BPCR_AVBP;
694 		vactive_end = reg_read(ldev->regs, LTDC_AWCR) & AWCR_AAH;
695 		vtotal = reg_read(ldev->regs, LTDC_TWCR) & TWCR_TOTALH;
696 
697 		if (line > vactive_end)
698 			*vpos = line - vtotal - vactive_start;
699 		else
700 			*vpos = line - vactive_start;
701 	} else {
702 		*vpos = 0;
703 	}
704 
705 	*hpos = 0;
706 
707 	if (etime)
708 		*etime = ktime_get();
709 
710 	return true;
711 }
712 
713 static const struct drm_crtc_funcs ltdc_crtc_funcs = {
714 	.destroy = drm_crtc_cleanup,
715 	.set_config = drm_atomic_helper_set_config,
716 	.page_flip = drm_atomic_helper_page_flip,
717 	.reset = drm_atomic_helper_crtc_reset,
718 	.atomic_duplicate_state = drm_atomic_helper_crtc_duplicate_state,
719 	.atomic_destroy_state = drm_atomic_helper_crtc_destroy_state,
720 	.enable_vblank = ltdc_crtc_enable_vblank,
721 	.disable_vblank = ltdc_crtc_disable_vblank,
722 	.gamma_set = drm_atomic_helper_legacy_gamma_set,
723 };
724 
725 /*
726  * DRM_PLANE
727  */
728 
729 static int ltdc_plane_atomic_check(struct drm_plane *plane,
730 				   struct drm_plane_state *state)
731 {
732 	struct drm_framebuffer *fb = state->fb;
733 	u32 src_w, src_h;
734 
735 	DRM_DEBUG_DRIVER("\n");
736 
737 	if (!fb)
738 		return 0;
739 
740 	/* convert src_ from 16:16 format */
741 	src_w = state->src_w >> 16;
742 	src_h = state->src_h >> 16;
743 
744 	/* Reject scaling */
745 	if (src_w != state->crtc_w || src_h != state->crtc_h) {
746 		DRM_ERROR("Scaling is not supported");
747 		return -EINVAL;
748 	}
749 
750 	return 0;
751 }
752 
753 static void ltdc_plane_atomic_update(struct drm_plane *plane,
754 				     struct drm_plane_state *oldstate)
755 {
756 	struct ltdc_device *ldev = plane_to_ltdc(plane);
757 	struct drm_plane_state *state = plane->state;
758 	struct drm_framebuffer *fb = state->fb;
759 	u32 lofs = plane->index * LAY_OFS;
760 	u32 x0 = state->crtc_x;
761 	u32 x1 = state->crtc_x + state->crtc_w - 1;
762 	u32 y0 = state->crtc_y;
763 	u32 y1 = state->crtc_y + state->crtc_h - 1;
764 	u32 src_x, src_y, src_w, src_h;
765 	u32 val, pitch_in_bytes, line_length, paddr, ahbp, avbp, bpcr;
766 	enum ltdc_pix_fmt pf;
767 
768 	if (!state->crtc || !fb) {
769 		DRM_DEBUG_DRIVER("fb or crtc NULL");
770 		return;
771 	}
772 
773 	/* convert src_ from 16:16 format */
774 	src_x = state->src_x >> 16;
775 	src_y = state->src_y >> 16;
776 	src_w = state->src_w >> 16;
777 	src_h = state->src_h >> 16;
778 
779 	DRM_DEBUG_DRIVER("plane:%d fb:%d (%dx%d)@(%d,%d) -> (%dx%d)@(%d,%d)\n",
780 			 plane->base.id, fb->base.id,
781 			 src_w, src_h, src_x, src_y,
782 			 state->crtc_w, state->crtc_h,
783 			 state->crtc_x, state->crtc_y);
784 
785 	bpcr = reg_read(ldev->regs, LTDC_BPCR);
786 	ahbp = (bpcr & BPCR_AHBP) >> 16;
787 	avbp = bpcr & BPCR_AVBP;
788 
789 	/* Configures the horizontal start and stop position */
790 	val = ((x1 + 1 + ahbp) << 16) + (x0 + 1 + ahbp);
791 	reg_update_bits(ldev->regs, LTDC_L1WHPCR + lofs,
792 			LXWHPCR_WHSTPOS | LXWHPCR_WHSPPOS, val);
793 
794 	/* Configures the vertical start and stop position */
795 	val = ((y1 + 1 + avbp) << 16) + (y0 + 1 + avbp);
796 	reg_update_bits(ldev->regs, LTDC_L1WVPCR + lofs,
797 			LXWVPCR_WVSTPOS | LXWVPCR_WVSPPOS, val);
798 
799 	/* Specifies the pixel format */
800 	pf = to_ltdc_pixelformat(fb->format->format);
801 	for (val = 0; val < NB_PF; val++)
802 		if (ldev->caps.pix_fmt_hw[val] == pf)
803 			break;
804 
805 	if (val == NB_PF) {
806 		DRM_ERROR("Pixel format %.4s not supported\n",
807 			  (char *)&fb->format->format);
808 		val = 0;	/* set by default ARGB 32 bits */
809 	}
810 	reg_update_bits(ldev->regs, LTDC_L1PFCR + lofs, LXPFCR_PF, val);
811 
812 	/* Configures the color frame buffer pitch in bytes & line length */
813 	pitch_in_bytes = fb->pitches[0];
814 	line_length = fb->format->cpp[0] *
815 		      (x1 - x0 + 1) + (ldev->caps.bus_width >> 3) - 1;
816 	val = ((pitch_in_bytes << 16) | line_length);
817 	reg_update_bits(ldev->regs, LTDC_L1CFBLR + lofs,
818 			LXCFBLR_CFBLL | LXCFBLR_CFBP, val);
819 
820 	/* Specifies the constant alpha value */
821 	val = CONSTA_MAX;
822 	reg_update_bits(ldev->regs, LTDC_L1CACR + lofs, LXCACR_CONSTA, val);
823 
824 	/* Specifies the blending factors */
825 	val = BF1_PAXCA | BF2_1PAXCA;
826 	if (!fb->format->has_alpha)
827 		val = BF1_CA | BF2_1CA;
828 
829 	/* Manage hw-specific capabilities */
830 	if (ldev->caps.non_alpha_only_l1 &&
831 	    plane->type != DRM_PLANE_TYPE_PRIMARY)
832 		val = BF1_PAXCA | BF2_1PAXCA;
833 
834 	reg_update_bits(ldev->regs, LTDC_L1BFCR + lofs,
835 			LXBFCR_BF2 | LXBFCR_BF1, val);
836 
837 	/* Configures the frame buffer line number */
838 	val = y1 - y0 + 1;
839 	reg_update_bits(ldev->regs, LTDC_L1CFBLNR + lofs, LXCFBLNR_CFBLN, val);
840 
841 	/* Sets the FB address */
842 	paddr = (u32)drm_fb_cma_get_gem_addr(fb, state, 0);
843 
844 	DRM_DEBUG_DRIVER("fb: phys 0x%08x", paddr);
845 	reg_write(ldev->regs, LTDC_L1CFBAR + lofs, paddr);
846 
847 	/* Enable layer and CLUT if needed */
848 	val = fb->format->format == DRM_FORMAT_C8 ? LXCR_CLUTEN : 0;
849 	val |= LXCR_LEN;
850 	reg_update_bits(ldev->regs, LTDC_L1CR + lofs,
851 			LXCR_LEN | LXCR_CLUTEN, val);
852 
853 	ldev->plane_fpsi[plane->index].counter++;
854 
855 	mutex_lock(&ldev->err_lock);
856 	if (ldev->error_status & ISR_FUIF) {
857 		DRM_WARN("ltdc fifo underrun: please verify display mode\n");
858 		ldev->error_status &= ~ISR_FUIF;
859 	}
860 	if (ldev->error_status & ISR_TERRIF) {
861 		DRM_WARN("ltdc transfer error\n");
862 		ldev->error_status &= ~ISR_TERRIF;
863 	}
864 	mutex_unlock(&ldev->err_lock);
865 }
866 
867 static void ltdc_plane_atomic_disable(struct drm_plane *plane,
868 				      struct drm_plane_state *oldstate)
869 {
870 	struct ltdc_device *ldev = plane_to_ltdc(plane);
871 	u32 lofs = plane->index * LAY_OFS;
872 
873 	/* disable layer */
874 	reg_clear(ldev->regs, LTDC_L1CR + lofs, LXCR_LEN);
875 
876 	DRM_DEBUG_DRIVER("CRTC:%d plane:%d\n",
877 			 oldstate->crtc->base.id, plane->base.id);
878 }
879 
880 static void ltdc_plane_atomic_print_state(struct drm_printer *p,
881 					  const struct drm_plane_state *state)
882 {
883 	struct drm_plane *plane = state->plane;
884 	struct ltdc_device *ldev = plane_to_ltdc(plane);
885 	struct fps_info *fpsi = &ldev->plane_fpsi[plane->index];
886 	int ms_since_last;
887 	ktime_t now;
888 
889 	now = ktime_get();
890 	ms_since_last = ktime_to_ms(ktime_sub(now, fpsi->last_timestamp));
891 
892 	drm_printf(p, "\tuser_updates=%dfps\n",
893 		   DIV_ROUND_CLOSEST(fpsi->counter * 1000, ms_since_last));
894 
895 	fpsi->last_timestamp = now;
896 	fpsi->counter = 0;
897 }
898 
899 static bool ltdc_plane_format_mod_supported(struct drm_plane *plane,
900 					    u32 format,
901 					    u64 modifier)
902 {
903 	if (modifier == DRM_FORMAT_MOD_LINEAR)
904 		return true;
905 
906 	return false;
907 }
908 
909 static const struct drm_plane_funcs ltdc_plane_funcs = {
910 	.update_plane = drm_atomic_helper_update_plane,
911 	.disable_plane = drm_atomic_helper_disable_plane,
912 	.destroy = drm_plane_cleanup,
913 	.reset = drm_atomic_helper_plane_reset,
914 	.atomic_duplicate_state = drm_atomic_helper_plane_duplicate_state,
915 	.atomic_destroy_state = drm_atomic_helper_plane_destroy_state,
916 	.atomic_print_state = ltdc_plane_atomic_print_state,
917 	.format_mod_supported = ltdc_plane_format_mod_supported,
918 };
919 
920 static const struct drm_plane_helper_funcs ltdc_plane_helper_funcs = {
921 	.prepare_fb = drm_gem_fb_prepare_fb,
922 	.atomic_check = ltdc_plane_atomic_check,
923 	.atomic_update = ltdc_plane_atomic_update,
924 	.atomic_disable = ltdc_plane_atomic_disable,
925 };
926 
927 static struct drm_plane *ltdc_plane_create(struct drm_device *ddev,
928 					   enum drm_plane_type type)
929 {
930 	unsigned long possible_crtcs = CRTC_MASK;
931 	struct ltdc_device *ldev = ddev->dev_private;
932 	struct device *dev = ddev->dev;
933 	struct drm_plane *plane;
934 	unsigned int i, nb_fmt = 0;
935 	u32 formats[NB_PF * 2];
936 	u32 drm_fmt, drm_fmt_no_alpha;
937 	const u64 *modifiers = ltdc_format_modifiers;
938 	int ret;
939 
940 	/* Get supported pixel formats */
941 	for (i = 0; i < NB_PF; i++) {
942 		drm_fmt = to_drm_pixelformat(ldev->caps.pix_fmt_hw[i]);
943 		if (!drm_fmt)
944 			continue;
945 		formats[nb_fmt++] = drm_fmt;
946 
947 		/* Add the no-alpha related format if any & supported */
948 		drm_fmt_no_alpha = get_pixelformat_without_alpha(drm_fmt);
949 		if (!drm_fmt_no_alpha)
950 			continue;
951 
952 		/* Manage hw-specific capabilities */
953 		if (ldev->caps.non_alpha_only_l1 &&
954 		    type != DRM_PLANE_TYPE_PRIMARY)
955 			continue;
956 
957 		formats[nb_fmt++] = drm_fmt_no_alpha;
958 	}
959 
960 	plane = devm_kzalloc(dev, sizeof(*plane), GFP_KERNEL);
961 	if (!plane)
962 		return NULL;
963 
964 	ret = drm_universal_plane_init(ddev, plane, possible_crtcs,
965 				       &ltdc_plane_funcs, formats, nb_fmt,
966 				       modifiers, type, NULL);
967 	if (ret < 0)
968 		return NULL;
969 
970 	drm_plane_helper_add(plane, &ltdc_plane_helper_funcs);
971 
972 	DRM_DEBUG_DRIVER("plane:%d created\n", plane->base.id);
973 
974 	return plane;
975 }
976 
977 static void ltdc_plane_destroy_all(struct drm_device *ddev)
978 {
979 	struct drm_plane *plane, *plane_temp;
980 
981 	list_for_each_entry_safe(plane, plane_temp,
982 				 &ddev->mode_config.plane_list, head)
983 		drm_plane_cleanup(plane);
984 }
985 
986 static int ltdc_crtc_init(struct drm_device *ddev, struct drm_crtc *crtc)
987 {
988 	struct ltdc_device *ldev = ddev->dev_private;
989 	struct drm_plane *primary, *overlay;
990 	unsigned int i;
991 	int ret;
992 
993 	primary = ltdc_plane_create(ddev, DRM_PLANE_TYPE_PRIMARY);
994 	if (!primary) {
995 		DRM_ERROR("Can not create primary plane\n");
996 		return -EINVAL;
997 	}
998 
999 	ret = drm_crtc_init_with_planes(ddev, crtc, primary, NULL,
1000 					&ltdc_crtc_funcs, NULL);
1001 	if (ret) {
1002 		DRM_ERROR("Can not initialize CRTC\n");
1003 		goto cleanup;
1004 	}
1005 
1006 	drm_crtc_helper_add(crtc, &ltdc_crtc_helper_funcs);
1007 
1008 	drm_mode_crtc_set_gamma_size(crtc, CLUT_SIZE);
1009 	drm_crtc_enable_color_mgmt(crtc, 0, false, CLUT_SIZE);
1010 
1011 	DRM_DEBUG_DRIVER("CRTC:%d created\n", crtc->base.id);
1012 
1013 	/* Add planes. Note : the first layer is used by primary plane */
1014 	for (i = 1; i < ldev->caps.nb_layers; i++) {
1015 		overlay = ltdc_plane_create(ddev, DRM_PLANE_TYPE_OVERLAY);
1016 		if (!overlay) {
1017 			ret = -ENOMEM;
1018 			DRM_ERROR("Can not create overlay plane %d\n", i);
1019 			goto cleanup;
1020 		}
1021 	}
1022 
1023 	return 0;
1024 
1025 cleanup:
1026 	ltdc_plane_destroy_all(ddev);
1027 	return ret;
1028 }
1029 
1030 /*
1031  * DRM_ENCODER
1032  */
1033 
1034 static const struct drm_encoder_funcs ltdc_encoder_funcs = {
1035 	.destroy = drm_encoder_cleanup,
1036 };
1037 
1038 static void ltdc_encoder_disable(struct drm_encoder *encoder)
1039 {
1040 	struct drm_device *ddev = encoder->dev;
1041 	struct ltdc_device *ldev = ddev->dev_private;
1042 
1043 	DRM_DEBUG_DRIVER("\n");
1044 
1045 	/* Disable LTDC */
1046 	reg_clear(ldev->regs, LTDC_GCR, GCR_LTDCEN);
1047 
1048 	/* Set to sleep state the pinctrl whatever type of encoder */
1049 	pinctrl_pm_select_sleep_state(ddev->dev);
1050 }
1051 
1052 static void ltdc_encoder_enable(struct drm_encoder *encoder)
1053 {
1054 	struct drm_device *ddev = encoder->dev;
1055 	struct ltdc_device *ldev = ddev->dev_private;
1056 
1057 	DRM_DEBUG_DRIVER("\n");
1058 
1059 	/* Enable LTDC */
1060 	reg_set(ldev->regs, LTDC_GCR, GCR_LTDCEN);
1061 }
1062 
1063 static void ltdc_encoder_mode_set(struct drm_encoder *encoder,
1064 				  struct drm_display_mode *mode,
1065 				  struct drm_display_mode *adjusted_mode)
1066 {
1067 	struct drm_device *ddev = encoder->dev;
1068 
1069 	DRM_DEBUG_DRIVER("\n");
1070 
1071 	/*
1072 	 * Set to default state the pinctrl only with DPI type.
1073 	 * Others types like DSI, don't need pinctrl due to
1074 	 * internal bridge (the signals do not come out of the chipset).
1075 	 */
1076 	if (encoder->encoder_type == DRM_MODE_ENCODER_DPI)
1077 		pinctrl_pm_select_default_state(ddev->dev);
1078 }
1079 
1080 static const struct drm_encoder_helper_funcs ltdc_encoder_helper_funcs = {
1081 	.disable = ltdc_encoder_disable,
1082 	.enable = ltdc_encoder_enable,
1083 	.mode_set = ltdc_encoder_mode_set,
1084 };
1085 
1086 static int ltdc_encoder_init(struct drm_device *ddev, struct drm_bridge *bridge)
1087 {
1088 	struct drm_encoder *encoder;
1089 	int ret;
1090 
1091 	encoder = devm_kzalloc(ddev->dev, sizeof(*encoder), GFP_KERNEL);
1092 	if (!encoder)
1093 		return -ENOMEM;
1094 
1095 	encoder->possible_crtcs = CRTC_MASK;
1096 	encoder->possible_clones = 0;	/* No cloning support */
1097 
1098 	drm_encoder_init(ddev, encoder, &ltdc_encoder_funcs,
1099 			 DRM_MODE_ENCODER_DPI, NULL);
1100 
1101 	drm_encoder_helper_add(encoder, &ltdc_encoder_helper_funcs);
1102 
1103 	ret = drm_bridge_attach(encoder, bridge, NULL);
1104 	if (ret) {
1105 		drm_encoder_cleanup(encoder);
1106 		return -EINVAL;
1107 	}
1108 
1109 	DRM_DEBUG_DRIVER("Bridge encoder:%d created\n", encoder->base.id);
1110 
1111 	return 0;
1112 }
1113 
1114 static int ltdc_get_caps(struct drm_device *ddev)
1115 {
1116 	struct ltdc_device *ldev = ddev->dev_private;
1117 	u32 bus_width_log2, lcr, gc2r;
1118 
1119 	/*
1120 	 * at least 1 layer must be managed & the number of layers
1121 	 * must not exceed LTDC_MAX_LAYER
1122 	 */
1123 	lcr = reg_read(ldev->regs, LTDC_LCR);
1124 
1125 	ldev->caps.nb_layers = clamp((int)lcr, 1, LTDC_MAX_LAYER);
1126 
1127 	/* set data bus width */
1128 	gc2r = reg_read(ldev->regs, LTDC_GC2R);
1129 	bus_width_log2 = (gc2r & GC2R_BW) >> 4;
1130 	ldev->caps.bus_width = 8 << bus_width_log2;
1131 	ldev->caps.hw_version = reg_read(ldev->regs, LTDC_IDR);
1132 
1133 	switch (ldev->caps.hw_version) {
1134 	case HWVER_10200:
1135 	case HWVER_10300:
1136 		ldev->caps.reg_ofs = REG_OFS_NONE;
1137 		ldev->caps.pix_fmt_hw = ltdc_pix_fmt_a0;
1138 		/*
1139 		 * Hw older versions support non-alpha color formats derived
1140 		 * from native alpha color formats only on the primary layer.
1141 		 * For instance, RG16 native format without alpha works fine
1142 		 * on 2nd layer but XR24 (derived color format from AR24)
1143 		 * does not work on 2nd layer.
1144 		 */
1145 		ldev->caps.non_alpha_only_l1 = true;
1146 		ldev->caps.pad_max_freq_hz = 90000000;
1147 		if (ldev->caps.hw_version == HWVER_10200)
1148 			ldev->caps.pad_max_freq_hz = 65000000;
1149 		break;
1150 	case HWVER_20101:
1151 		ldev->caps.reg_ofs = REG_OFS_4;
1152 		ldev->caps.pix_fmt_hw = ltdc_pix_fmt_a1;
1153 		ldev->caps.non_alpha_only_l1 = false;
1154 		ldev->caps.pad_max_freq_hz = 150000000;
1155 		break;
1156 	default:
1157 		return -ENODEV;
1158 	}
1159 
1160 	return 0;
1161 }
1162 
1163 void ltdc_suspend(struct drm_device *ddev)
1164 {
1165 	struct ltdc_device *ldev = ddev->dev_private;
1166 
1167 	DRM_DEBUG_DRIVER("\n");
1168 	clk_disable_unprepare(ldev->pixel_clk);
1169 }
1170 
1171 int ltdc_resume(struct drm_device *ddev)
1172 {
1173 	struct ltdc_device *ldev = ddev->dev_private;
1174 	int ret;
1175 
1176 	DRM_DEBUG_DRIVER("\n");
1177 
1178 	ret = clk_prepare_enable(ldev->pixel_clk);
1179 	if (ret) {
1180 		DRM_ERROR("failed to enable pixel clock (%d)\n", ret);
1181 		return ret;
1182 	}
1183 
1184 	return 0;
1185 }
1186 
1187 int ltdc_load(struct drm_device *ddev)
1188 {
1189 	struct platform_device *pdev = to_platform_device(ddev->dev);
1190 	struct ltdc_device *ldev = ddev->dev_private;
1191 	struct device *dev = ddev->dev;
1192 	struct device_node *np = dev->of_node;
1193 	struct drm_bridge *bridge[MAX_ENDPOINTS] = {NULL};
1194 	struct drm_panel *panel[MAX_ENDPOINTS] = {NULL};
1195 	struct drm_crtc *crtc;
1196 	struct reset_control *rstc;
1197 	struct resource *res;
1198 	int irq, ret, i, endpoint_not_ready = -ENODEV;
1199 
1200 	DRM_DEBUG_DRIVER("\n");
1201 
1202 	/* Get endpoints if any */
1203 	for (i = 0; i < MAX_ENDPOINTS; i++) {
1204 		ret = drm_of_find_panel_or_bridge(np, 0, i, &panel[i],
1205 						  &bridge[i]);
1206 
1207 		/*
1208 		 * If at least one endpoint is -EPROBE_DEFER, defer probing,
1209 		 * else if at least one endpoint is ready, continue probing.
1210 		 */
1211 		if (ret == -EPROBE_DEFER)
1212 			return ret;
1213 		else if (!ret)
1214 			endpoint_not_ready = 0;
1215 	}
1216 
1217 	if (endpoint_not_ready)
1218 		return endpoint_not_ready;
1219 
1220 	rstc = devm_reset_control_get_exclusive(dev, NULL);
1221 
1222 	mutex_init(&ldev->err_lock);
1223 
1224 	ldev->pixel_clk = devm_clk_get(dev, "lcd");
1225 	if (IS_ERR(ldev->pixel_clk)) {
1226 		if (PTR_ERR(ldev->pixel_clk) != -EPROBE_DEFER)
1227 			DRM_ERROR("Unable to get lcd clock\n");
1228 		return PTR_ERR(ldev->pixel_clk);
1229 	}
1230 
1231 	if (clk_prepare_enable(ldev->pixel_clk)) {
1232 		DRM_ERROR("Unable to prepare pixel clock\n");
1233 		return -ENODEV;
1234 	}
1235 
1236 	if (!IS_ERR(rstc)) {
1237 		reset_control_assert(rstc);
1238 		usleep_range(10, 20);
1239 		reset_control_deassert(rstc);
1240 	}
1241 
1242 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1243 	ldev->regs = devm_ioremap_resource(dev, res);
1244 	if (IS_ERR(ldev->regs)) {
1245 		DRM_ERROR("Unable to get ltdc registers\n");
1246 		ret = PTR_ERR(ldev->regs);
1247 		goto err;
1248 	}
1249 
1250 	/* Disable interrupts */
1251 	reg_clear(ldev->regs, LTDC_IER,
1252 		  IER_LIE | IER_RRIE | IER_FUIE | IER_TERRIE);
1253 
1254 	for (i = 0; i < MAX_IRQ; i++) {
1255 		irq = platform_get_irq(pdev, i);
1256 		if (irq == -EPROBE_DEFER)
1257 			goto err;
1258 
1259 		if (irq < 0)
1260 			continue;
1261 
1262 		ret = devm_request_threaded_irq(dev, irq, ltdc_irq,
1263 						ltdc_irq_thread, IRQF_ONESHOT,
1264 						dev_name(dev), ddev);
1265 		if (ret) {
1266 			DRM_ERROR("Failed to register LTDC interrupt\n");
1267 			goto err;
1268 		}
1269 	}
1270 
1271 
1272 	ret = ltdc_get_caps(ddev);
1273 	if (ret) {
1274 		DRM_ERROR("hardware identifier (0x%08x) not supported!\n",
1275 			  ldev->caps.hw_version);
1276 		goto err;
1277 	}
1278 
1279 	DRM_DEBUG_DRIVER("ltdc hw version 0x%08x\n", ldev->caps.hw_version);
1280 
1281 	/* Add endpoints panels or bridges if any */
1282 	for (i = 0; i < MAX_ENDPOINTS; i++) {
1283 		if (panel[i]) {
1284 			bridge[i] = drm_panel_bridge_add_typed(panel[i],
1285 							       DRM_MODE_CONNECTOR_DPI);
1286 			if (IS_ERR(bridge[i])) {
1287 				DRM_ERROR("panel-bridge endpoint %d\n", i);
1288 				ret = PTR_ERR(bridge[i]);
1289 				goto err;
1290 			}
1291 		}
1292 
1293 		if (bridge[i]) {
1294 			ret = ltdc_encoder_init(ddev, bridge[i]);
1295 			if (ret) {
1296 				DRM_ERROR("init encoder endpoint %d\n", i);
1297 				goto err;
1298 			}
1299 		}
1300 	}
1301 
1302 	crtc = devm_kzalloc(dev, sizeof(*crtc), GFP_KERNEL);
1303 	if (!crtc) {
1304 		DRM_ERROR("Failed to allocate crtc\n");
1305 		ret = -ENOMEM;
1306 		goto err;
1307 	}
1308 
1309 	ddev->mode_config.allow_fb_modifiers = true;
1310 
1311 	ret = ltdc_crtc_init(ddev, crtc);
1312 	if (ret) {
1313 		DRM_ERROR("Failed to init crtc\n");
1314 		goto err;
1315 	}
1316 
1317 	ret = drm_vblank_init(ddev, NB_CRTC);
1318 	if (ret) {
1319 		DRM_ERROR("Failed calling drm_vblank_init()\n");
1320 		goto err;
1321 	}
1322 
1323 	/* Allow usage of vblank without having to call drm_irq_install */
1324 	ddev->irq_enabled = 1;
1325 
1326 	clk_disable_unprepare(ldev->pixel_clk);
1327 
1328 	pinctrl_pm_select_sleep_state(ddev->dev);
1329 
1330 	pm_runtime_enable(ddev->dev);
1331 
1332 	return 0;
1333 err:
1334 	for (i = 0; i < MAX_ENDPOINTS; i++)
1335 		drm_panel_bridge_remove(bridge[i]);
1336 
1337 	clk_disable_unprepare(ldev->pixel_clk);
1338 
1339 	return ret;
1340 }
1341 
1342 void ltdc_unload(struct drm_device *ddev)
1343 {
1344 	int i;
1345 
1346 	DRM_DEBUG_DRIVER("\n");
1347 
1348 	for (i = 0; i < MAX_ENDPOINTS; i++)
1349 		drm_of_panel_bridge_remove(ddev->dev->of_node, 0, i);
1350 
1351 	pm_runtime_disable(ddev->dev);
1352 }
1353 
1354 MODULE_AUTHOR("Philippe Cornu <philippe.cornu@st.com>");
1355 MODULE_AUTHOR("Yannick Fertre <yannick.fertre@st.com>");
1356 MODULE_AUTHOR("Fabien Dessenne <fabien.dessenne@st.com>");
1357 MODULE_AUTHOR("Mickael Reulier <mickael.reulier@st.com>");
1358 MODULE_DESCRIPTION("STMicroelectronics ST DRM LTDC driver");
1359 MODULE_LICENSE("GPL v2");
1360