xref: /openbmc/linux/drivers/gpu/drm/stm/ltdc.c (revision 84b102f5)
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 HWVER_10200 0x010200
46 #define HWVER_10300 0x010300
47 #define HWVER_20101 0x020101
48 
49 /*
50  * The address of some registers depends on the HW version: such registers have
51  * an extra offset specified with reg_ofs.
52  */
53 #define REG_OFS_NONE	0
54 #define REG_OFS_4	4		/* Insertion of "Layer Conf. 2" reg */
55 #define REG_OFS		(ldev->caps.reg_ofs)
56 #define LAY_OFS		0x80		/* Register Offset between 2 layers */
57 
58 /* Global register offsets */
59 #define LTDC_IDR	0x0000		/* IDentification */
60 #define LTDC_LCR	0x0004		/* Layer Count */
61 #define LTDC_SSCR	0x0008		/* Synchronization Size Configuration */
62 #define LTDC_BPCR	0x000C		/* Back Porch Configuration */
63 #define LTDC_AWCR	0x0010		/* Active Width Configuration */
64 #define LTDC_TWCR	0x0014		/* Total Width Configuration */
65 #define LTDC_GCR	0x0018		/* Global Control */
66 #define LTDC_GC1R	0x001C		/* Global Configuration 1 */
67 #define LTDC_GC2R	0x0020		/* Global Configuration 2 */
68 #define LTDC_SRCR	0x0024		/* Shadow Reload Configuration */
69 #define LTDC_GACR	0x0028		/* GAmma Correction */
70 #define LTDC_BCCR	0x002C		/* Background Color Configuration */
71 #define LTDC_IER	0x0034		/* Interrupt Enable */
72 #define LTDC_ISR	0x0038		/* Interrupt Status */
73 #define LTDC_ICR	0x003C		/* Interrupt Clear */
74 #define LTDC_LIPCR	0x0040		/* Line Interrupt Position Conf. */
75 #define LTDC_CPSR	0x0044		/* Current Position Status */
76 #define LTDC_CDSR	0x0048		/* Current Display Status */
77 
78 /* Layer register offsets */
79 #define LTDC_L1LC1R	(0x80)		/* L1 Layer Configuration 1 */
80 #define LTDC_L1LC2R	(0x84)		/* L1 Layer Configuration 2 */
81 #define LTDC_L1CR	(0x84 + REG_OFS)/* L1 Control */
82 #define LTDC_L1WHPCR	(0x88 + REG_OFS)/* L1 Window Hor Position Config */
83 #define LTDC_L1WVPCR	(0x8C + REG_OFS)/* L1 Window Vert Position Config */
84 #define LTDC_L1CKCR	(0x90 + REG_OFS)/* L1 Color Keying Configuration */
85 #define LTDC_L1PFCR	(0x94 + REG_OFS)/* L1 Pixel Format Configuration */
86 #define LTDC_L1CACR	(0x98 + REG_OFS)/* L1 Constant Alpha Config */
87 #define LTDC_L1DCCR	(0x9C + REG_OFS)/* L1 Default Color Configuration */
88 #define LTDC_L1BFCR	(0xA0 + REG_OFS)/* L1 Blend Factors Configuration */
89 #define LTDC_L1FBBCR	(0xA4 + REG_OFS)/* L1 FrameBuffer Bus Control */
90 #define LTDC_L1AFBCR	(0xA8 + REG_OFS)/* L1 AuxFB Control */
91 #define LTDC_L1CFBAR	(0xAC + REG_OFS)/* L1 Color FrameBuffer Address */
92 #define LTDC_L1CFBLR	(0xB0 + REG_OFS)/* L1 Color FrameBuffer Length */
93 #define LTDC_L1CFBLNR	(0xB4 + REG_OFS)/* L1 Color FrameBuffer Line Nb */
94 #define LTDC_L1AFBAR	(0xB8 + REG_OFS)/* L1 AuxFB Address */
95 #define LTDC_L1AFBLR	(0xBC + REG_OFS)/* L1 AuxFB Length */
96 #define LTDC_L1AFBLNR	(0xC0 + REG_OFS)/* L1 AuxFB Line Number */
97 #define LTDC_L1CLUTWR	(0xC4 + REG_OFS)/* L1 CLUT Write */
98 #define LTDC_L1YS1R	(0xE0 + REG_OFS)/* L1 YCbCr Scale 1 */
99 #define LTDC_L1YS2R	(0xE4 + REG_OFS)/* L1 YCbCr Scale 2 */
100 
101 /* Bit definitions */
102 #define SSCR_VSH	GENMASK(10, 0)	/* Vertical Synchronization Height */
103 #define SSCR_HSW	GENMASK(27, 16)	/* Horizontal Synchronization Width */
104 
105 #define BPCR_AVBP	GENMASK(10, 0)	/* Accumulated Vertical Back Porch */
106 #define BPCR_AHBP	GENMASK(27, 16)	/* Accumulated Horizontal Back Porch */
107 
108 #define AWCR_AAH	GENMASK(10, 0)	/* Accumulated Active Height */
109 #define AWCR_AAW	GENMASK(27, 16)	/* Accumulated Active Width */
110 
111 #define TWCR_TOTALH	GENMASK(10, 0)	/* TOTAL Height */
112 #define TWCR_TOTALW	GENMASK(27, 16)	/* TOTAL Width */
113 
114 #define GCR_LTDCEN	BIT(0)		/* LTDC ENable */
115 #define GCR_DEN		BIT(16)		/* Dither ENable */
116 #define GCR_PCPOL	BIT(28)		/* Pixel Clock POLarity-Inverted */
117 #define GCR_DEPOL	BIT(29)		/* Data Enable POLarity-High */
118 #define GCR_VSPOL	BIT(30)		/* Vertical Synchro POLarity-High */
119 #define GCR_HSPOL	BIT(31)		/* Horizontal Synchro POLarity-High */
120 
121 #define GC1R_WBCH	GENMASK(3, 0)	/* Width of Blue CHannel output */
122 #define GC1R_WGCH	GENMASK(7, 4)	/* Width of Green Channel output */
123 #define GC1R_WRCH	GENMASK(11, 8)	/* Width of Red Channel output */
124 #define GC1R_PBEN	BIT(12)		/* Precise Blending ENable */
125 #define GC1R_DT		GENMASK(15, 14)	/* Dithering Technique */
126 #define GC1R_GCT	GENMASK(19, 17)	/* Gamma Correction Technique */
127 #define GC1R_SHREN	BIT(21)		/* SHadow Registers ENabled */
128 #define GC1R_BCP	BIT(22)		/* Background Colour Programmable */
129 #define GC1R_BBEN	BIT(23)		/* Background Blending ENabled */
130 #define GC1R_LNIP	BIT(24)		/* Line Number IRQ Position */
131 #define GC1R_TP		BIT(25)		/* Timing Programmable */
132 #define GC1R_IPP	BIT(26)		/* IRQ Polarity Programmable */
133 #define GC1R_SPP	BIT(27)		/* Sync Polarity Programmable */
134 #define GC1R_DWP	BIT(28)		/* Dither Width Programmable */
135 #define GC1R_STREN	BIT(29)		/* STatus Registers ENabled */
136 #define GC1R_BMEN	BIT(31)		/* Blind Mode ENabled */
137 
138 #define GC2R_EDCA	BIT(0)		/* External Display Control Ability  */
139 #define GC2R_STSAEN	BIT(1)		/* Slave Timing Sync Ability ENabled */
140 #define GC2R_DVAEN	BIT(2)		/* Dual-View Ability ENabled */
141 #define GC2R_DPAEN	BIT(3)		/* Dual-Port Ability ENabled */
142 #define GC2R_BW		GENMASK(6, 4)	/* Bus Width (log2 of nb of bytes) */
143 #define GC2R_EDCEN	BIT(7)		/* External Display Control ENabled */
144 
145 #define SRCR_IMR	BIT(0)		/* IMmediate Reload */
146 #define SRCR_VBR	BIT(1)		/* Vertical Blanking Reload */
147 
148 #define BCCR_BCBLACK	0x00		/* Background Color BLACK */
149 #define BCCR_BCBLUE	GENMASK(7, 0)	/* Background Color BLUE */
150 #define BCCR_BCGREEN	GENMASK(15, 8)	/* Background Color GREEN */
151 #define BCCR_BCRED	GENMASK(23, 16)	/* Background Color RED */
152 #define BCCR_BCWHITE	GENMASK(23, 0)	/* Background Color WHITE */
153 
154 #define IER_LIE		BIT(0)		/* Line Interrupt Enable */
155 #define IER_FUIE	BIT(1)		/* Fifo Underrun Interrupt Enable */
156 #define IER_TERRIE	BIT(2)		/* Transfer ERRor Interrupt Enable */
157 #define IER_RRIE	BIT(3)		/* Register Reload Interrupt enable */
158 
159 #define CPSR_CYPOS	GENMASK(15, 0)	/* Current Y position */
160 
161 #define ISR_LIF		BIT(0)		/* Line Interrupt Flag */
162 #define ISR_FUIF	BIT(1)		/* Fifo Underrun Interrupt Flag */
163 #define ISR_TERRIF	BIT(2)		/* Transfer ERRor Interrupt Flag */
164 #define ISR_RRIF	BIT(3)		/* Register Reload Interrupt Flag */
165 
166 #define LXCR_LEN	BIT(0)		/* Layer ENable */
167 #define LXCR_COLKEN	BIT(1)		/* Color Keying Enable */
168 #define LXCR_CLUTEN	BIT(4)		/* Color Look-Up Table ENable */
169 
170 #define LXWHPCR_WHSTPOS	GENMASK(11, 0)	/* Window Horizontal StarT POSition */
171 #define LXWHPCR_WHSPPOS	GENMASK(27, 16)	/* Window Horizontal StoP POSition */
172 
173 #define LXWVPCR_WVSTPOS	GENMASK(10, 0)	/* Window Vertical StarT POSition */
174 #define LXWVPCR_WVSPPOS	GENMASK(26, 16)	/* Window Vertical StoP POSition */
175 
176 #define LXPFCR_PF	GENMASK(2, 0)	/* Pixel Format */
177 
178 #define LXCACR_CONSTA	GENMASK(7, 0)	/* CONSTant Alpha */
179 
180 #define LXBFCR_BF2	GENMASK(2, 0)	/* Blending Factor 2 */
181 #define LXBFCR_BF1	GENMASK(10, 8)	/* Blending Factor 1 */
182 
183 #define LXCFBLR_CFBLL	GENMASK(12, 0)	/* Color Frame Buffer Line Length */
184 #define LXCFBLR_CFBP	GENMASK(28, 16)	/* Color Frame Buffer Pitch in bytes */
185 
186 #define LXCFBLNR_CFBLN	GENMASK(10, 0)	/* Color Frame Buffer Line Number */
187 
188 #define CLUT_SIZE	256
189 
190 #define CONSTA_MAX	0xFF		/* CONSTant Alpha MAX= 1.0 */
191 #define BF1_PAXCA	0x600		/* Pixel Alpha x Constant Alpha */
192 #define BF1_CA		0x400		/* Constant Alpha */
193 #define BF2_1PAXCA	0x007		/* 1 - (Pixel Alpha x Constant Alpha) */
194 #define BF2_1CA		0x005		/* 1 - Constant Alpha */
195 
196 #define NB_PF		8		/* Max nb of HW pixel format */
197 
198 enum ltdc_pix_fmt {
199 	PF_NONE,
200 	/* RGB formats */
201 	PF_ARGB8888,		/* ARGB [32 bits] */
202 	PF_RGBA8888,		/* RGBA [32 bits] */
203 	PF_RGB888,		/* RGB [24 bits] */
204 	PF_RGB565,		/* RGB [16 bits] */
205 	PF_ARGB1555,		/* ARGB A:1 bit RGB:15 bits [16 bits] */
206 	PF_ARGB4444,		/* ARGB A:4 bits R/G/B: 4 bits each [16 bits] */
207 	/* Indexed formats */
208 	PF_L8,			/* Indexed 8 bits [8 bits] */
209 	PF_AL44,		/* Alpha:4 bits + indexed 4 bits [8 bits] */
210 	PF_AL88			/* Alpha:8 bits + indexed 8 bits [16 bits] */
211 };
212 
213 /* The index gives the encoding of the pixel format for an HW version */
214 static const enum ltdc_pix_fmt ltdc_pix_fmt_a0[NB_PF] = {
215 	PF_ARGB8888,		/* 0x00 */
216 	PF_RGB888,		/* 0x01 */
217 	PF_RGB565,		/* 0x02 */
218 	PF_ARGB1555,		/* 0x03 */
219 	PF_ARGB4444,		/* 0x04 */
220 	PF_L8,			/* 0x05 */
221 	PF_AL44,		/* 0x06 */
222 	PF_AL88			/* 0x07 */
223 };
224 
225 static const enum ltdc_pix_fmt ltdc_pix_fmt_a1[NB_PF] = {
226 	PF_ARGB8888,		/* 0x00 */
227 	PF_RGB888,		/* 0x01 */
228 	PF_RGB565,		/* 0x02 */
229 	PF_RGBA8888,		/* 0x03 */
230 	PF_AL44,		/* 0x04 */
231 	PF_L8,			/* 0x05 */
232 	PF_ARGB1555,		/* 0x06 */
233 	PF_ARGB4444		/* 0x07 */
234 };
235 
236 static const u64 ltdc_format_modifiers[] = {
237 	DRM_FORMAT_MOD_LINEAR,
238 	DRM_FORMAT_MOD_INVALID
239 };
240 
241 static inline u32 reg_read(void __iomem *base, u32 reg)
242 {
243 	return readl_relaxed(base + reg);
244 }
245 
246 static inline void reg_write(void __iomem *base, u32 reg, u32 val)
247 {
248 	writel_relaxed(val, base + reg);
249 }
250 
251 static inline void reg_set(void __iomem *base, u32 reg, u32 mask)
252 {
253 	reg_write(base, reg, reg_read(base, reg) | mask);
254 }
255 
256 static inline void reg_clear(void __iomem *base, u32 reg, u32 mask)
257 {
258 	reg_write(base, reg, reg_read(base, reg) & ~mask);
259 }
260 
261 static inline void reg_update_bits(void __iomem *base, u32 reg, u32 mask,
262 				   u32 val)
263 {
264 	reg_write(base, reg, (reg_read(base, reg) & ~mask) | val);
265 }
266 
267 static inline struct ltdc_device *crtc_to_ltdc(struct drm_crtc *crtc)
268 {
269 	return (struct ltdc_device *)crtc->dev->dev_private;
270 }
271 
272 static inline struct ltdc_device *plane_to_ltdc(struct drm_plane *plane)
273 {
274 	return (struct ltdc_device *)plane->dev->dev_private;
275 }
276 
277 static inline struct ltdc_device *encoder_to_ltdc(struct drm_encoder *enc)
278 {
279 	return (struct ltdc_device *)enc->dev->dev_private;
280 }
281 
282 static inline enum ltdc_pix_fmt to_ltdc_pixelformat(u32 drm_fmt)
283 {
284 	enum ltdc_pix_fmt pf;
285 
286 	switch (drm_fmt) {
287 	case DRM_FORMAT_ARGB8888:
288 	case DRM_FORMAT_XRGB8888:
289 		pf = PF_ARGB8888;
290 		break;
291 	case DRM_FORMAT_RGBA8888:
292 	case DRM_FORMAT_RGBX8888:
293 		pf = PF_RGBA8888;
294 		break;
295 	case DRM_FORMAT_RGB888:
296 		pf = PF_RGB888;
297 		break;
298 	case DRM_FORMAT_RGB565:
299 		pf = PF_RGB565;
300 		break;
301 	case DRM_FORMAT_ARGB1555:
302 	case DRM_FORMAT_XRGB1555:
303 		pf = PF_ARGB1555;
304 		break;
305 	case DRM_FORMAT_ARGB4444:
306 	case DRM_FORMAT_XRGB4444:
307 		pf = PF_ARGB4444;
308 		break;
309 	case DRM_FORMAT_C8:
310 		pf = PF_L8;
311 		break;
312 	default:
313 		pf = PF_NONE;
314 		break;
315 		/* Note: There are no DRM_FORMAT for AL44 and AL88 */
316 	}
317 
318 	return pf;
319 }
320 
321 static inline u32 to_drm_pixelformat(enum ltdc_pix_fmt pf)
322 {
323 	switch (pf) {
324 	case PF_ARGB8888:
325 		return DRM_FORMAT_ARGB8888;
326 	case PF_RGBA8888:
327 		return DRM_FORMAT_RGBA8888;
328 	case PF_RGB888:
329 		return DRM_FORMAT_RGB888;
330 	case PF_RGB565:
331 		return DRM_FORMAT_RGB565;
332 	case PF_ARGB1555:
333 		return DRM_FORMAT_ARGB1555;
334 	case PF_ARGB4444:
335 		return DRM_FORMAT_ARGB4444;
336 	case PF_L8:
337 		return DRM_FORMAT_C8;
338 	case PF_AL44:		/* No DRM support */
339 	case PF_AL88:		/* No DRM support */
340 	case PF_NONE:
341 	default:
342 		return 0;
343 	}
344 }
345 
346 static inline u32 get_pixelformat_without_alpha(u32 drm)
347 {
348 	switch (drm) {
349 	case DRM_FORMAT_ARGB4444:
350 		return DRM_FORMAT_XRGB4444;
351 	case DRM_FORMAT_RGBA4444:
352 		return DRM_FORMAT_RGBX4444;
353 	case DRM_FORMAT_ARGB1555:
354 		return DRM_FORMAT_XRGB1555;
355 	case DRM_FORMAT_RGBA5551:
356 		return DRM_FORMAT_RGBX5551;
357 	case DRM_FORMAT_ARGB8888:
358 		return DRM_FORMAT_XRGB8888;
359 	case DRM_FORMAT_RGBA8888:
360 		return DRM_FORMAT_RGBX8888;
361 	default:
362 		return 0;
363 	}
364 }
365 
366 static irqreturn_t ltdc_irq_thread(int irq, void *arg)
367 {
368 	struct drm_device *ddev = arg;
369 	struct ltdc_device *ldev = ddev->dev_private;
370 	struct drm_crtc *crtc = drm_crtc_from_index(ddev, 0);
371 
372 	/* Line IRQ : trigger the vblank event */
373 	if (ldev->irq_status & ISR_LIF)
374 		drm_crtc_handle_vblank(crtc);
375 
376 	/* Save FIFO Underrun & Transfer Error status */
377 	mutex_lock(&ldev->err_lock);
378 	if (ldev->irq_status & ISR_FUIF)
379 		ldev->error_status |= ISR_FUIF;
380 	if (ldev->irq_status & ISR_TERRIF)
381 		ldev->error_status |= ISR_TERRIF;
382 	mutex_unlock(&ldev->err_lock);
383 
384 	return IRQ_HANDLED;
385 }
386 
387 static irqreturn_t ltdc_irq(int irq, void *arg)
388 {
389 	struct drm_device *ddev = arg;
390 	struct ltdc_device *ldev = ddev->dev_private;
391 
392 	/* Read & Clear the interrupt status */
393 	ldev->irq_status = reg_read(ldev->regs, LTDC_ISR);
394 	reg_write(ldev->regs, LTDC_ICR, ldev->irq_status);
395 
396 	return IRQ_WAKE_THREAD;
397 }
398 
399 /*
400  * DRM_CRTC
401  */
402 
403 static void ltdc_crtc_update_clut(struct drm_crtc *crtc)
404 {
405 	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
406 	struct drm_color_lut *lut;
407 	u32 val;
408 	int i;
409 
410 	if (!crtc->state->color_mgmt_changed || !crtc->state->gamma_lut)
411 		return;
412 
413 	lut = (struct drm_color_lut *)crtc->state->gamma_lut->data;
414 
415 	for (i = 0; i < CLUT_SIZE; i++, lut++) {
416 		val = ((lut->red << 8) & 0xff0000) | (lut->green & 0xff00) |
417 			(lut->blue >> 8) | (i << 24);
418 		reg_write(ldev->regs, LTDC_L1CLUTWR, val);
419 	}
420 }
421 
422 static void ltdc_crtc_atomic_enable(struct drm_crtc *crtc,
423 				    struct drm_atomic_state *state)
424 {
425 	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
426 	struct drm_device *ddev = crtc->dev;
427 
428 	DRM_DEBUG_DRIVER("\n");
429 
430 	pm_runtime_get_sync(ddev->dev);
431 
432 	/* Sets the background color value */
433 	reg_write(ldev->regs, LTDC_BCCR, BCCR_BCBLACK);
434 
435 	/* Enable IRQ */
436 	reg_set(ldev->regs, LTDC_IER, IER_RRIE | IER_FUIE | IER_TERRIE);
437 
438 	/* Commit shadow registers = update planes at next vblank */
439 	reg_set(ldev->regs, LTDC_SRCR, SRCR_VBR);
440 
441 	drm_crtc_vblank_on(crtc);
442 }
443 
444 static void ltdc_crtc_atomic_disable(struct drm_crtc *crtc,
445 				     struct drm_atomic_state *state)
446 {
447 	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
448 	struct drm_device *ddev = crtc->dev;
449 
450 	DRM_DEBUG_DRIVER("\n");
451 
452 	drm_crtc_vblank_off(crtc);
453 
454 	/* disable IRQ */
455 	reg_clear(ldev->regs, LTDC_IER, IER_RRIE | IER_FUIE | IER_TERRIE);
456 
457 	/* immediately commit disable of layers before switching off LTDC */
458 	reg_set(ldev->regs, LTDC_SRCR, SRCR_IMR);
459 
460 	pm_runtime_put_sync(ddev->dev);
461 }
462 
463 #define CLK_TOLERANCE_HZ 50
464 
465 static enum drm_mode_status
466 ltdc_crtc_mode_valid(struct drm_crtc *crtc,
467 		     const struct drm_display_mode *mode)
468 {
469 	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
470 	int target = mode->clock * 1000;
471 	int target_min = target - CLK_TOLERANCE_HZ;
472 	int target_max = target + CLK_TOLERANCE_HZ;
473 	int result;
474 
475 	result = clk_round_rate(ldev->pixel_clk, target);
476 
477 	DRM_DEBUG_DRIVER("clk rate target %d, available %d\n", target, result);
478 
479 	/* Filter modes according to the max frequency supported by the pads */
480 	if (result > ldev->caps.pad_max_freq_hz)
481 		return MODE_CLOCK_HIGH;
482 
483 	/*
484 	 * Accept all "preferred" modes:
485 	 * - this is important for panels because panel clock tolerances are
486 	 *   bigger than hdmi ones and there is no reason to not accept them
487 	 *   (the fps may vary a little but it is not a problem).
488 	 * - the hdmi preferred mode will be accepted too, but userland will
489 	 *   be able to use others hdmi "valid" modes if necessary.
490 	 */
491 	if (mode->type & DRM_MODE_TYPE_PREFERRED)
492 		return MODE_OK;
493 
494 	/*
495 	 * Filter modes according to the clock value, particularly useful for
496 	 * hdmi modes that require precise pixel clocks.
497 	 */
498 	if (result < target_min || result > target_max)
499 		return MODE_CLOCK_RANGE;
500 
501 	return MODE_OK;
502 }
503 
504 static bool ltdc_crtc_mode_fixup(struct drm_crtc *crtc,
505 				 const struct drm_display_mode *mode,
506 				 struct drm_display_mode *adjusted_mode)
507 {
508 	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
509 	int rate = mode->clock * 1000;
510 
511 	if (clk_set_rate(ldev->pixel_clk, rate) < 0) {
512 		DRM_ERROR("Cannot set rate (%dHz) for pixel clk\n", rate);
513 		return false;
514 	}
515 
516 	adjusted_mode->clock = clk_get_rate(ldev->pixel_clk) / 1000;
517 
518 	DRM_DEBUG_DRIVER("requested clock %dkHz, adjusted clock %dkHz\n",
519 			 mode->clock, adjusted_mode->clock);
520 
521 	return true;
522 }
523 
524 static void ltdc_crtc_mode_set_nofb(struct drm_crtc *crtc)
525 {
526 	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
527 	struct drm_device *ddev = crtc->dev;
528 	struct drm_display_mode *mode = &crtc->state->adjusted_mode;
529 	struct videomode vm;
530 	u32 hsync, vsync, accum_hbp, accum_vbp, accum_act_w, accum_act_h;
531 	u32 total_width, total_height;
532 	u32 val;
533 	int ret;
534 
535 	if (!pm_runtime_active(ddev->dev)) {
536 		ret = pm_runtime_get_sync(ddev->dev);
537 		if (ret) {
538 			DRM_ERROR("Failed to set mode, cannot get sync\n");
539 			return;
540 		}
541 	}
542 
543 	drm_display_mode_to_videomode(mode, &vm);
544 
545 	DRM_DEBUG_DRIVER("CRTC:%d mode:%s\n", crtc->base.id, mode->name);
546 	DRM_DEBUG_DRIVER("Video mode: %dx%d", vm.hactive, vm.vactive);
547 	DRM_DEBUG_DRIVER(" hfp %d hbp %d hsl %d vfp %d vbp %d vsl %d\n",
548 			 vm.hfront_porch, vm.hback_porch, vm.hsync_len,
549 			 vm.vfront_porch, vm.vback_porch, vm.vsync_len);
550 
551 	/* Convert video timings to ltdc timings */
552 	hsync = vm.hsync_len - 1;
553 	vsync = vm.vsync_len - 1;
554 	accum_hbp = hsync + vm.hback_porch;
555 	accum_vbp = vsync + vm.vback_porch;
556 	accum_act_w = accum_hbp + vm.hactive;
557 	accum_act_h = accum_vbp + vm.vactive;
558 	total_width = accum_act_w + vm.hfront_porch;
559 	total_height = accum_act_h + vm.vfront_porch;
560 
561 	/* Configures the HS, VS, DE and PC polarities. Default Active Low */
562 	val = 0;
563 
564 	if (vm.flags & DISPLAY_FLAGS_HSYNC_HIGH)
565 		val |= GCR_HSPOL;
566 
567 	if (vm.flags & DISPLAY_FLAGS_VSYNC_HIGH)
568 		val |= GCR_VSPOL;
569 
570 	if (vm.flags & DISPLAY_FLAGS_DE_LOW)
571 		val |= GCR_DEPOL;
572 
573 	if (vm.flags & DISPLAY_FLAGS_PIXDATA_NEGEDGE)
574 		val |= GCR_PCPOL;
575 
576 	reg_update_bits(ldev->regs, LTDC_GCR,
577 			GCR_HSPOL | GCR_VSPOL | GCR_DEPOL | GCR_PCPOL, val);
578 
579 	/* Set Synchronization size */
580 	val = (hsync << 16) | vsync;
581 	reg_update_bits(ldev->regs, LTDC_SSCR, SSCR_VSH | SSCR_HSW, val);
582 
583 	/* Set Accumulated Back porch */
584 	val = (accum_hbp << 16) | accum_vbp;
585 	reg_update_bits(ldev->regs, LTDC_BPCR, BPCR_AVBP | BPCR_AHBP, val);
586 
587 	/* Set Accumulated Active Width */
588 	val = (accum_act_w << 16) | accum_act_h;
589 	reg_update_bits(ldev->regs, LTDC_AWCR, AWCR_AAW | AWCR_AAH, val);
590 
591 	/* Set total width & height */
592 	val = (total_width << 16) | total_height;
593 	reg_update_bits(ldev->regs, LTDC_TWCR, TWCR_TOTALH | TWCR_TOTALW, val);
594 
595 	reg_write(ldev->regs, LTDC_LIPCR, (accum_act_h + 1));
596 }
597 
598 static void ltdc_crtc_atomic_flush(struct drm_crtc *crtc,
599 				   struct drm_atomic_state *state)
600 {
601 	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
602 	struct drm_device *ddev = crtc->dev;
603 	struct drm_pending_vblank_event *event = crtc->state->event;
604 
605 	DRM_DEBUG_ATOMIC("\n");
606 
607 	ltdc_crtc_update_clut(crtc);
608 
609 	/* Commit shadow registers = update planes at next vblank */
610 	reg_set(ldev->regs, LTDC_SRCR, SRCR_VBR);
611 
612 	if (event) {
613 		crtc->state->event = NULL;
614 
615 		spin_lock_irq(&ddev->event_lock);
616 		if (drm_crtc_vblank_get(crtc) == 0)
617 			drm_crtc_arm_vblank_event(crtc, event);
618 		else
619 			drm_crtc_send_vblank_event(crtc, event);
620 		spin_unlock_irq(&ddev->event_lock);
621 	}
622 }
623 
624 static bool ltdc_crtc_get_scanout_position(struct drm_crtc *crtc,
625 					   bool in_vblank_irq,
626 					   int *vpos, int *hpos,
627 					   ktime_t *stime, ktime_t *etime,
628 					   const struct drm_display_mode *mode)
629 {
630 	struct drm_device *ddev = crtc->dev;
631 	struct ltdc_device *ldev = ddev->dev_private;
632 	int line, vactive_start, vactive_end, vtotal;
633 
634 	if (stime)
635 		*stime = ktime_get();
636 
637 	/* The active area starts after vsync + front porch and ends
638 	 * at vsync + front porc + display size.
639 	 * The total height also include back porch.
640 	 * We have 3 possible cases to handle:
641 	 * - line < vactive_start: vpos = line - vactive_start and will be
642 	 * negative
643 	 * - vactive_start < line < vactive_end: vpos = line - vactive_start
644 	 * and will be positive
645 	 * - line > vactive_end: vpos = line - vtotal - vactive_start
646 	 * and will negative
647 	 *
648 	 * Computation for the two first cases are identical so we can
649 	 * simplify the code and only test if line > vactive_end
650 	 */
651 	if (pm_runtime_active(ddev->dev)) {
652 		line = reg_read(ldev->regs, LTDC_CPSR) & CPSR_CYPOS;
653 		vactive_start = reg_read(ldev->regs, LTDC_BPCR) & BPCR_AVBP;
654 		vactive_end = reg_read(ldev->regs, LTDC_AWCR) & AWCR_AAH;
655 		vtotal = reg_read(ldev->regs, LTDC_TWCR) & TWCR_TOTALH;
656 
657 		if (line > vactive_end)
658 			*vpos = line - vtotal - vactive_start;
659 		else
660 			*vpos = line - vactive_start;
661 	} else {
662 		*vpos = 0;
663 	}
664 
665 	*hpos = 0;
666 
667 	if (etime)
668 		*etime = ktime_get();
669 
670 	return true;
671 }
672 
673 static const struct drm_crtc_helper_funcs ltdc_crtc_helper_funcs = {
674 	.mode_valid = ltdc_crtc_mode_valid,
675 	.mode_fixup = ltdc_crtc_mode_fixup,
676 	.mode_set_nofb = ltdc_crtc_mode_set_nofb,
677 	.atomic_flush = ltdc_crtc_atomic_flush,
678 	.atomic_enable = ltdc_crtc_atomic_enable,
679 	.atomic_disable = ltdc_crtc_atomic_disable,
680 	.get_scanout_position = ltdc_crtc_get_scanout_position,
681 };
682 
683 static int ltdc_crtc_enable_vblank(struct drm_crtc *crtc)
684 {
685 	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
686 	struct drm_crtc_state *state = crtc->state;
687 
688 	DRM_DEBUG_DRIVER("\n");
689 
690 	if (state->enable)
691 		reg_set(ldev->regs, LTDC_IER, IER_LIE);
692 	else
693 		return -EPERM;
694 
695 	return 0;
696 }
697 
698 static void ltdc_crtc_disable_vblank(struct drm_crtc *crtc)
699 {
700 	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
701 
702 	DRM_DEBUG_DRIVER("\n");
703 	reg_clear(ldev->regs, LTDC_IER, IER_LIE);
704 }
705 
706 static const struct drm_crtc_funcs ltdc_crtc_funcs = {
707 	.destroy = drm_crtc_cleanup,
708 	.set_config = drm_atomic_helper_set_config,
709 	.page_flip = drm_atomic_helper_page_flip,
710 	.reset = drm_atomic_helper_crtc_reset,
711 	.atomic_duplicate_state = drm_atomic_helper_crtc_duplicate_state,
712 	.atomic_destroy_state = drm_atomic_helper_crtc_destroy_state,
713 	.enable_vblank = ltdc_crtc_enable_vblank,
714 	.disable_vblank = ltdc_crtc_disable_vblank,
715 	.get_vblank_timestamp = drm_crtc_vblank_helper_get_vblank_timestamp,
716 	.gamma_set = drm_atomic_helper_legacy_gamma_set,
717 };
718 
719 /*
720  * DRM_PLANE
721  */
722 
723 static int ltdc_plane_atomic_check(struct drm_plane *plane,
724 				   struct drm_plane_state *state)
725 {
726 	struct drm_framebuffer *fb = state->fb;
727 	u32 src_w, src_h;
728 
729 	DRM_DEBUG_DRIVER("\n");
730 
731 	if (!fb)
732 		return 0;
733 
734 	/* convert src_ from 16:16 format */
735 	src_w = state->src_w >> 16;
736 	src_h = state->src_h >> 16;
737 
738 	/* Reject scaling */
739 	if (src_w != state->crtc_w || src_h != state->crtc_h) {
740 		DRM_ERROR("Scaling is not supported");
741 		return -EINVAL;
742 	}
743 
744 	return 0;
745 }
746 
747 static void ltdc_plane_atomic_update(struct drm_plane *plane,
748 				     struct drm_plane_state *oldstate)
749 {
750 	struct ltdc_device *ldev = plane_to_ltdc(plane);
751 	struct drm_plane_state *state = plane->state;
752 	struct drm_framebuffer *fb = state->fb;
753 	u32 lofs = plane->index * LAY_OFS;
754 	u32 x0 = state->crtc_x;
755 	u32 x1 = state->crtc_x + state->crtc_w - 1;
756 	u32 y0 = state->crtc_y;
757 	u32 y1 = state->crtc_y + state->crtc_h - 1;
758 	u32 src_x, src_y, src_w, src_h;
759 	u32 val, pitch_in_bytes, line_length, paddr, ahbp, avbp, bpcr;
760 	enum ltdc_pix_fmt pf;
761 
762 	if (!state->crtc || !fb) {
763 		DRM_DEBUG_DRIVER("fb or crtc NULL");
764 		return;
765 	}
766 
767 	/* convert src_ from 16:16 format */
768 	src_x = state->src_x >> 16;
769 	src_y = state->src_y >> 16;
770 	src_w = state->src_w >> 16;
771 	src_h = state->src_h >> 16;
772 
773 	DRM_DEBUG_DRIVER("plane:%d fb:%d (%dx%d)@(%d,%d) -> (%dx%d)@(%d,%d)\n",
774 			 plane->base.id, fb->base.id,
775 			 src_w, src_h, src_x, src_y,
776 			 state->crtc_w, state->crtc_h,
777 			 state->crtc_x, state->crtc_y);
778 
779 	bpcr = reg_read(ldev->regs, LTDC_BPCR);
780 	ahbp = (bpcr & BPCR_AHBP) >> 16;
781 	avbp = bpcr & BPCR_AVBP;
782 
783 	/* Configures the horizontal start and stop position */
784 	val = ((x1 + 1 + ahbp) << 16) + (x0 + 1 + ahbp);
785 	reg_update_bits(ldev->regs, LTDC_L1WHPCR + lofs,
786 			LXWHPCR_WHSTPOS | LXWHPCR_WHSPPOS, val);
787 
788 	/* Configures the vertical start and stop position */
789 	val = ((y1 + 1 + avbp) << 16) + (y0 + 1 + avbp);
790 	reg_update_bits(ldev->regs, LTDC_L1WVPCR + lofs,
791 			LXWVPCR_WVSTPOS | LXWVPCR_WVSPPOS, val);
792 
793 	/* Specifies the pixel format */
794 	pf = to_ltdc_pixelformat(fb->format->format);
795 	for (val = 0; val < NB_PF; val++)
796 		if (ldev->caps.pix_fmt_hw[val] == pf)
797 			break;
798 
799 	if (val == NB_PF) {
800 		DRM_ERROR("Pixel format %.4s not supported\n",
801 			  (char *)&fb->format->format);
802 		val = 0;	/* set by default ARGB 32 bits */
803 	}
804 	reg_update_bits(ldev->regs, LTDC_L1PFCR + lofs, LXPFCR_PF, val);
805 
806 	/* Configures the color frame buffer pitch in bytes & line length */
807 	pitch_in_bytes = fb->pitches[0];
808 	line_length = fb->format->cpp[0] *
809 		      (x1 - x0 + 1) + (ldev->caps.bus_width >> 3) - 1;
810 	val = ((pitch_in_bytes << 16) | line_length);
811 	reg_update_bits(ldev->regs, LTDC_L1CFBLR + lofs,
812 			LXCFBLR_CFBLL | LXCFBLR_CFBP, val);
813 
814 	/* Specifies the constant alpha value */
815 	val = CONSTA_MAX;
816 	reg_update_bits(ldev->regs, LTDC_L1CACR + lofs, LXCACR_CONSTA, val);
817 
818 	/* Specifies the blending factors */
819 	val = BF1_PAXCA | BF2_1PAXCA;
820 	if (!fb->format->has_alpha)
821 		val = BF1_CA | BF2_1CA;
822 
823 	/* Manage hw-specific capabilities */
824 	if (ldev->caps.non_alpha_only_l1 &&
825 	    plane->type != DRM_PLANE_TYPE_PRIMARY)
826 		val = BF1_PAXCA | BF2_1PAXCA;
827 
828 	reg_update_bits(ldev->regs, LTDC_L1BFCR + lofs,
829 			LXBFCR_BF2 | LXBFCR_BF1, val);
830 
831 	/* Configures the frame buffer line number */
832 	val = y1 - y0 + 1;
833 	reg_update_bits(ldev->regs, LTDC_L1CFBLNR + lofs, LXCFBLNR_CFBLN, val);
834 
835 	/* Sets the FB address */
836 	paddr = (u32)drm_fb_cma_get_gem_addr(fb, state, 0);
837 
838 	DRM_DEBUG_DRIVER("fb: phys 0x%08x", paddr);
839 	reg_write(ldev->regs, LTDC_L1CFBAR + lofs, paddr);
840 
841 	/* Enable layer and CLUT if needed */
842 	val = fb->format->format == DRM_FORMAT_C8 ? LXCR_CLUTEN : 0;
843 	val |= LXCR_LEN;
844 	reg_update_bits(ldev->regs, LTDC_L1CR + lofs,
845 			LXCR_LEN | LXCR_CLUTEN, val);
846 
847 	ldev->plane_fpsi[plane->index].counter++;
848 
849 	mutex_lock(&ldev->err_lock);
850 	if (ldev->error_status & ISR_FUIF) {
851 		DRM_WARN("ltdc fifo underrun: please verify display mode\n");
852 		ldev->error_status &= ~ISR_FUIF;
853 	}
854 	if (ldev->error_status & ISR_TERRIF) {
855 		DRM_WARN("ltdc transfer error\n");
856 		ldev->error_status &= ~ISR_TERRIF;
857 	}
858 	mutex_unlock(&ldev->err_lock);
859 }
860 
861 static void ltdc_plane_atomic_disable(struct drm_plane *plane,
862 				      struct drm_plane_state *oldstate)
863 {
864 	struct ltdc_device *ldev = plane_to_ltdc(plane);
865 	u32 lofs = plane->index * LAY_OFS;
866 
867 	/* disable layer */
868 	reg_clear(ldev->regs, LTDC_L1CR + lofs, LXCR_LEN);
869 
870 	DRM_DEBUG_DRIVER("CRTC:%d plane:%d\n",
871 			 oldstate->crtc->base.id, plane->base.id);
872 }
873 
874 static void ltdc_plane_atomic_print_state(struct drm_printer *p,
875 					  const struct drm_plane_state *state)
876 {
877 	struct drm_plane *plane = state->plane;
878 	struct ltdc_device *ldev = plane_to_ltdc(plane);
879 	struct fps_info *fpsi = &ldev->plane_fpsi[plane->index];
880 	int ms_since_last;
881 	ktime_t now;
882 
883 	now = ktime_get();
884 	ms_since_last = ktime_to_ms(ktime_sub(now, fpsi->last_timestamp));
885 
886 	drm_printf(p, "\tuser_updates=%dfps\n",
887 		   DIV_ROUND_CLOSEST(fpsi->counter * 1000, ms_since_last));
888 
889 	fpsi->last_timestamp = now;
890 	fpsi->counter = 0;
891 }
892 
893 static bool ltdc_plane_format_mod_supported(struct drm_plane *plane,
894 					    u32 format,
895 					    u64 modifier)
896 {
897 	if (modifier == DRM_FORMAT_MOD_LINEAR)
898 		return true;
899 
900 	return false;
901 }
902 
903 static const struct drm_plane_funcs ltdc_plane_funcs = {
904 	.update_plane = drm_atomic_helper_update_plane,
905 	.disable_plane = drm_atomic_helper_disable_plane,
906 	.destroy = drm_plane_cleanup,
907 	.reset = drm_atomic_helper_plane_reset,
908 	.atomic_duplicate_state = drm_atomic_helper_plane_duplicate_state,
909 	.atomic_destroy_state = drm_atomic_helper_plane_destroy_state,
910 	.atomic_print_state = ltdc_plane_atomic_print_state,
911 	.format_mod_supported = ltdc_plane_format_mod_supported,
912 };
913 
914 static const struct drm_plane_helper_funcs ltdc_plane_helper_funcs = {
915 	.prepare_fb = drm_gem_fb_prepare_fb,
916 	.atomic_check = ltdc_plane_atomic_check,
917 	.atomic_update = ltdc_plane_atomic_update,
918 	.atomic_disable = ltdc_plane_atomic_disable,
919 };
920 
921 static struct drm_plane *ltdc_plane_create(struct drm_device *ddev,
922 					   enum drm_plane_type type)
923 {
924 	unsigned long possible_crtcs = CRTC_MASK;
925 	struct ltdc_device *ldev = ddev->dev_private;
926 	struct device *dev = ddev->dev;
927 	struct drm_plane *plane;
928 	unsigned int i, nb_fmt = 0;
929 	u32 formats[NB_PF * 2];
930 	u32 drm_fmt, drm_fmt_no_alpha;
931 	const u64 *modifiers = ltdc_format_modifiers;
932 	int ret;
933 
934 	/* Get supported pixel formats */
935 	for (i = 0; i < NB_PF; i++) {
936 		drm_fmt = to_drm_pixelformat(ldev->caps.pix_fmt_hw[i]);
937 		if (!drm_fmt)
938 			continue;
939 		formats[nb_fmt++] = drm_fmt;
940 
941 		/* Add the no-alpha related format if any & supported */
942 		drm_fmt_no_alpha = get_pixelformat_without_alpha(drm_fmt);
943 		if (!drm_fmt_no_alpha)
944 			continue;
945 
946 		/* Manage hw-specific capabilities */
947 		if (ldev->caps.non_alpha_only_l1 &&
948 		    type != DRM_PLANE_TYPE_PRIMARY)
949 			continue;
950 
951 		formats[nb_fmt++] = drm_fmt_no_alpha;
952 	}
953 
954 	plane = devm_kzalloc(dev, sizeof(*plane), GFP_KERNEL);
955 	if (!plane)
956 		return NULL;
957 
958 	ret = drm_universal_plane_init(ddev, plane, possible_crtcs,
959 				       &ltdc_plane_funcs, formats, nb_fmt,
960 				       modifiers, type, NULL);
961 	if (ret < 0)
962 		return NULL;
963 
964 	drm_plane_helper_add(plane, &ltdc_plane_helper_funcs);
965 
966 	DRM_DEBUG_DRIVER("plane:%d created\n", plane->base.id);
967 
968 	return plane;
969 }
970 
971 static void ltdc_plane_destroy_all(struct drm_device *ddev)
972 {
973 	struct drm_plane *plane, *plane_temp;
974 
975 	list_for_each_entry_safe(plane, plane_temp,
976 				 &ddev->mode_config.plane_list, head)
977 		drm_plane_cleanup(plane);
978 }
979 
980 static int ltdc_crtc_init(struct drm_device *ddev, struct drm_crtc *crtc)
981 {
982 	struct ltdc_device *ldev = ddev->dev_private;
983 	struct drm_plane *primary, *overlay;
984 	unsigned int i;
985 	int ret;
986 
987 	primary = ltdc_plane_create(ddev, DRM_PLANE_TYPE_PRIMARY);
988 	if (!primary) {
989 		DRM_ERROR("Can not create primary plane\n");
990 		return -EINVAL;
991 	}
992 
993 	ret = drm_crtc_init_with_planes(ddev, crtc, primary, NULL,
994 					&ltdc_crtc_funcs, NULL);
995 	if (ret) {
996 		DRM_ERROR("Can not initialize CRTC\n");
997 		goto cleanup;
998 	}
999 
1000 	drm_crtc_helper_add(crtc, &ltdc_crtc_helper_funcs);
1001 
1002 	drm_mode_crtc_set_gamma_size(crtc, CLUT_SIZE);
1003 	drm_crtc_enable_color_mgmt(crtc, 0, false, CLUT_SIZE);
1004 
1005 	DRM_DEBUG_DRIVER("CRTC:%d created\n", crtc->base.id);
1006 
1007 	/* Add planes. Note : the first layer is used by primary plane */
1008 	for (i = 1; i < ldev->caps.nb_layers; i++) {
1009 		overlay = ltdc_plane_create(ddev, DRM_PLANE_TYPE_OVERLAY);
1010 		if (!overlay) {
1011 			ret = -ENOMEM;
1012 			DRM_ERROR("Can not create overlay plane %d\n", i);
1013 			goto cleanup;
1014 		}
1015 	}
1016 
1017 	return 0;
1018 
1019 cleanup:
1020 	ltdc_plane_destroy_all(ddev);
1021 	return ret;
1022 }
1023 
1024 /*
1025  * DRM_ENCODER
1026  */
1027 
1028 static const struct drm_encoder_funcs ltdc_encoder_funcs = {
1029 	.destroy = drm_encoder_cleanup,
1030 };
1031 
1032 static void ltdc_encoder_disable(struct drm_encoder *encoder)
1033 {
1034 	struct drm_device *ddev = encoder->dev;
1035 	struct ltdc_device *ldev = ddev->dev_private;
1036 
1037 	DRM_DEBUG_DRIVER("\n");
1038 
1039 	/* Disable LTDC */
1040 	reg_clear(ldev->regs, LTDC_GCR, GCR_LTDCEN);
1041 
1042 	/* Set to sleep state the pinctrl whatever type of encoder */
1043 	pinctrl_pm_select_sleep_state(ddev->dev);
1044 }
1045 
1046 static void ltdc_encoder_enable(struct drm_encoder *encoder)
1047 {
1048 	struct drm_device *ddev = encoder->dev;
1049 	struct ltdc_device *ldev = ddev->dev_private;
1050 
1051 	DRM_DEBUG_DRIVER("\n");
1052 
1053 	/* Enable LTDC */
1054 	reg_set(ldev->regs, LTDC_GCR, GCR_LTDCEN);
1055 }
1056 
1057 static void ltdc_encoder_mode_set(struct drm_encoder *encoder,
1058 				  struct drm_display_mode *mode,
1059 				  struct drm_display_mode *adjusted_mode)
1060 {
1061 	struct drm_device *ddev = encoder->dev;
1062 
1063 	DRM_DEBUG_DRIVER("\n");
1064 
1065 	/*
1066 	 * Set to default state the pinctrl only with DPI type.
1067 	 * Others types like DSI, don't need pinctrl due to
1068 	 * internal bridge (the signals do not come out of the chipset).
1069 	 */
1070 	if (encoder->encoder_type == DRM_MODE_ENCODER_DPI)
1071 		pinctrl_pm_select_default_state(ddev->dev);
1072 }
1073 
1074 static const struct drm_encoder_helper_funcs ltdc_encoder_helper_funcs = {
1075 	.disable = ltdc_encoder_disable,
1076 	.enable = ltdc_encoder_enable,
1077 	.mode_set = ltdc_encoder_mode_set,
1078 };
1079 
1080 static int ltdc_encoder_init(struct drm_device *ddev, struct drm_bridge *bridge)
1081 {
1082 	struct drm_encoder *encoder;
1083 	int ret;
1084 
1085 	encoder = devm_kzalloc(ddev->dev, sizeof(*encoder), GFP_KERNEL);
1086 	if (!encoder)
1087 		return -ENOMEM;
1088 
1089 	encoder->possible_crtcs = CRTC_MASK;
1090 	encoder->possible_clones = 0;	/* No cloning support */
1091 
1092 	drm_encoder_init(ddev, encoder, &ltdc_encoder_funcs,
1093 			 DRM_MODE_ENCODER_DPI, NULL);
1094 
1095 	drm_encoder_helper_add(encoder, &ltdc_encoder_helper_funcs);
1096 
1097 	ret = drm_bridge_attach(encoder, bridge, NULL, 0);
1098 	if (ret) {
1099 		drm_encoder_cleanup(encoder);
1100 		return -EINVAL;
1101 	}
1102 
1103 	DRM_DEBUG_DRIVER("Bridge encoder:%d created\n", encoder->base.id);
1104 
1105 	return 0;
1106 }
1107 
1108 static int ltdc_get_caps(struct drm_device *ddev)
1109 {
1110 	struct ltdc_device *ldev = ddev->dev_private;
1111 	u32 bus_width_log2, lcr, gc2r;
1112 
1113 	/*
1114 	 * at least 1 layer must be managed & the number of layers
1115 	 * must not exceed LTDC_MAX_LAYER
1116 	 */
1117 	lcr = reg_read(ldev->regs, LTDC_LCR);
1118 
1119 	ldev->caps.nb_layers = clamp((int)lcr, 1, LTDC_MAX_LAYER);
1120 
1121 	/* set data bus width */
1122 	gc2r = reg_read(ldev->regs, LTDC_GC2R);
1123 	bus_width_log2 = (gc2r & GC2R_BW) >> 4;
1124 	ldev->caps.bus_width = 8 << bus_width_log2;
1125 	ldev->caps.hw_version = reg_read(ldev->regs, LTDC_IDR);
1126 
1127 	switch (ldev->caps.hw_version) {
1128 	case HWVER_10200:
1129 	case HWVER_10300:
1130 		ldev->caps.reg_ofs = REG_OFS_NONE;
1131 		ldev->caps.pix_fmt_hw = ltdc_pix_fmt_a0;
1132 		/*
1133 		 * Hw older versions support non-alpha color formats derived
1134 		 * from native alpha color formats only on the primary layer.
1135 		 * For instance, RG16 native format without alpha works fine
1136 		 * on 2nd layer but XR24 (derived color format from AR24)
1137 		 * does not work on 2nd layer.
1138 		 */
1139 		ldev->caps.non_alpha_only_l1 = true;
1140 		ldev->caps.pad_max_freq_hz = 90000000;
1141 		if (ldev->caps.hw_version == HWVER_10200)
1142 			ldev->caps.pad_max_freq_hz = 65000000;
1143 		ldev->caps.nb_irq = 2;
1144 		break;
1145 	case HWVER_20101:
1146 		ldev->caps.reg_ofs = REG_OFS_4;
1147 		ldev->caps.pix_fmt_hw = ltdc_pix_fmt_a1;
1148 		ldev->caps.non_alpha_only_l1 = false;
1149 		ldev->caps.pad_max_freq_hz = 150000000;
1150 		ldev->caps.nb_irq = 4;
1151 		break;
1152 	default:
1153 		return -ENODEV;
1154 	}
1155 
1156 	return 0;
1157 }
1158 
1159 void ltdc_suspend(struct drm_device *ddev)
1160 {
1161 	struct ltdc_device *ldev = ddev->dev_private;
1162 
1163 	DRM_DEBUG_DRIVER("\n");
1164 	clk_disable_unprepare(ldev->pixel_clk);
1165 }
1166 
1167 int ltdc_resume(struct drm_device *ddev)
1168 {
1169 	struct ltdc_device *ldev = ddev->dev_private;
1170 	int ret;
1171 
1172 	DRM_DEBUG_DRIVER("\n");
1173 
1174 	ret = clk_prepare_enable(ldev->pixel_clk);
1175 	if (ret) {
1176 		DRM_ERROR("failed to enable pixel clock (%d)\n", ret);
1177 		return ret;
1178 	}
1179 
1180 	return 0;
1181 }
1182 
1183 int ltdc_load(struct drm_device *ddev)
1184 {
1185 	struct platform_device *pdev = to_platform_device(ddev->dev);
1186 	struct ltdc_device *ldev = ddev->dev_private;
1187 	struct device *dev = ddev->dev;
1188 	struct device_node *np = dev->of_node;
1189 	struct drm_bridge *bridge;
1190 	struct drm_panel *panel;
1191 	struct drm_crtc *crtc;
1192 	struct reset_control *rstc;
1193 	struct resource *res;
1194 	int irq, i, nb_endpoints;
1195 	int ret = -ENODEV;
1196 
1197 	DRM_DEBUG_DRIVER("\n");
1198 
1199 	/* Get number of endpoints */
1200 	nb_endpoints = of_graph_get_endpoint_count(np);
1201 	if (!nb_endpoints)
1202 		return -ENODEV;
1203 
1204 	ldev->pixel_clk = devm_clk_get(dev, "lcd");
1205 	if (IS_ERR(ldev->pixel_clk)) {
1206 		if (PTR_ERR(ldev->pixel_clk) != -EPROBE_DEFER)
1207 			DRM_ERROR("Unable to get lcd clock\n");
1208 		return PTR_ERR(ldev->pixel_clk);
1209 	}
1210 
1211 	if (clk_prepare_enable(ldev->pixel_clk)) {
1212 		DRM_ERROR("Unable to prepare pixel clock\n");
1213 		return -ENODEV;
1214 	}
1215 
1216 	/* Get endpoints if any */
1217 	for (i = 0; i < nb_endpoints; i++) {
1218 		ret = drm_of_find_panel_or_bridge(np, 0, i, &panel, &bridge);
1219 
1220 		/*
1221 		 * If at least one endpoint is -ENODEV, continue probing,
1222 		 * else if at least one endpoint returned an error
1223 		 * (ie -EPROBE_DEFER) then stop probing.
1224 		 */
1225 		if (ret == -ENODEV)
1226 			continue;
1227 		else if (ret)
1228 			goto err;
1229 
1230 		if (panel) {
1231 			bridge = drm_panel_bridge_add_typed(panel,
1232 							    DRM_MODE_CONNECTOR_DPI);
1233 			if (IS_ERR(bridge)) {
1234 				DRM_ERROR("panel-bridge endpoint %d\n", i);
1235 				ret = PTR_ERR(bridge);
1236 				goto err;
1237 			}
1238 		}
1239 
1240 		if (bridge) {
1241 			ret = ltdc_encoder_init(ddev, bridge);
1242 			if (ret) {
1243 				DRM_ERROR("init encoder endpoint %d\n", i);
1244 				goto err;
1245 			}
1246 		}
1247 	}
1248 
1249 	rstc = devm_reset_control_get_exclusive(dev, NULL);
1250 
1251 	mutex_init(&ldev->err_lock);
1252 
1253 	if (!IS_ERR(rstc)) {
1254 		reset_control_assert(rstc);
1255 		usleep_range(10, 20);
1256 		reset_control_deassert(rstc);
1257 	}
1258 
1259 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1260 	ldev->regs = devm_ioremap_resource(dev, res);
1261 	if (IS_ERR(ldev->regs)) {
1262 		DRM_ERROR("Unable to get ltdc registers\n");
1263 		ret = PTR_ERR(ldev->regs);
1264 		goto err;
1265 	}
1266 
1267 	/* Disable interrupts */
1268 	reg_clear(ldev->regs, LTDC_IER,
1269 		  IER_LIE | IER_RRIE | IER_FUIE | IER_TERRIE);
1270 
1271 	ret = ltdc_get_caps(ddev);
1272 	if (ret) {
1273 		DRM_ERROR("hardware identifier (0x%08x) not supported!\n",
1274 			  ldev->caps.hw_version);
1275 		goto err;
1276 	}
1277 
1278 	DRM_DEBUG_DRIVER("ltdc hw version 0x%08x\n", ldev->caps.hw_version);
1279 
1280 	for (i = 0; i < ldev->caps.nb_irq; i++) {
1281 		irq = platform_get_irq(pdev, i);
1282 		if (irq < 0) {
1283 			ret = irq;
1284 			goto err;
1285 		}
1286 
1287 		ret = devm_request_threaded_irq(dev, irq, ltdc_irq,
1288 						ltdc_irq_thread, IRQF_ONESHOT,
1289 						dev_name(dev), ddev);
1290 		if (ret) {
1291 			DRM_ERROR("Failed to register LTDC interrupt\n");
1292 			goto err;
1293 		}
1294 
1295 	}
1296 
1297 	crtc = devm_kzalloc(dev, sizeof(*crtc), GFP_KERNEL);
1298 	if (!crtc) {
1299 		DRM_ERROR("Failed to allocate crtc\n");
1300 		ret = -ENOMEM;
1301 		goto err;
1302 	}
1303 
1304 	ddev->mode_config.allow_fb_modifiers = true;
1305 
1306 	ret = ltdc_crtc_init(ddev, crtc);
1307 	if (ret) {
1308 		DRM_ERROR("Failed to init crtc\n");
1309 		goto err;
1310 	}
1311 
1312 	ret = drm_vblank_init(ddev, NB_CRTC);
1313 	if (ret) {
1314 		DRM_ERROR("Failed calling drm_vblank_init()\n");
1315 		goto err;
1316 	}
1317 
1318 	/* Allow usage of vblank without having to call drm_irq_install */
1319 	ddev->irq_enabled = 1;
1320 
1321 	clk_disable_unprepare(ldev->pixel_clk);
1322 
1323 	pinctrl_pm_select_sleep_state(ddev->dev);
1324 
1325 	pm_runtime_enable(ddev->dev);
1326 
1327 	return 0;
1328 err:
1329 	for (i = 0; i < nb_endpoints; i++)
1330 		drm_of_panel_bridge_remove(ddev->dev->of_node, 0, i);
1331 
1332 	clk_disable_unprepare(ldev->pixel_clk);
1333 
1334 	return ret;
1335 }
1336 
1337 void ltdc_unload(struct drm_device *ddev)
1338 {
1339 	struct device *dev = ddev->dev;
1340 	int nb_endpoints, i;
1341 
1342 	DRM_DEBUG_DRIVER("\n");
1343 
1344 	nb_endpoints = of_graph_get_endpoint_count(dev->of_node);
1345 
1346 	for (i = 0; i < nb_endpoints; i++)
1347 		drm_of_panel_bridge_remove(ddev->dev->of_node, 0, i);
1348 
1349 	pm_runtime_disable(ddev->dev);
1350 }
1351 
1352 MODULE_AUTHOR("Philippe Cornu <philippe.cornu@st.com>");
1353 MODULE_AUTHOR("Yannick Fertre <yannick.fertre@st.com>");
1354 MODULE_AUTHOR("Fabien Dessenne <fabien.dessenne@st.com>");
1355 MODULE_AUTHOR("Mickael Reulier <mickael.reulier@st.com>");
1356 MODULE_DESCRIPTION("STMicroelectronics ST DRM LTDC driver");
1357 MODULE_LICENSE("GPL v2");
1358