xref: /openbmc/linux/drivers/gpu/drm/stm/ltdc.c (revision 7d545e77)
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/platform_device.h>
19 #include <linux/pm_runtime.h>
20 #include <linux/reset.h>
21 
22 #include <drm/drm_atomic.h>
23 #include <drm/drm_atomic_helper.h>
24 #include <drm/drm_bridge.h>
25 #include <drm/drm_device.h>
26 #include <drm/drm_fb_cma_helper.h>
27 #include <drm/drm_fourcc.h>
28 #include <drm/drm_gem_cma_helper.h>
29 #include <drm/drm_of.h>
30 #include <drm/drm_plane_helper.h>
31 #include <drm/drm_probe_helper.h>
32 #include <drm/drm_vblank.h>
33 
34 #include <video/videomode.h>
35 
36 #include "ltdc.h"
37 
38 #define NB_CRTC 1
39 #define CRTC_MASK GENMASK(NB_CRTC - 1, 0)
40 
41 #define MAX_IRQ 4
42 
43 #define MAX_ENDPOINTS 2
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_crtc_state *old_state)
424 {
425 	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
426 
427 	DRM_DEBUG_DRIVER("\n");
428 
429 	/* Sets the background color value */
430 	reg_write(ldev->regs, LTDC_BCCR, BCCR_BCBLACK);
431 
432 	/* Enable IRQ */
433 	reg_set(ldev->regs, LTDC_IER, IER_RRIE | IER_FUIE | IER_TERRIE);
434 
435 	/* Commit shadow registers = update planes at next vblank */
436 	reg_set(ldev->regs, LTDC_SRCR, SRCR_VBR);
437 
438 	/* Enable LTDC */
439 	reg_set(ldev->regs, LTDC_GCR, GCR_LTDCEN);
440 
441 	drm_crtc_vblank_on(crtc);
442 }
443 
444 static void ltdc_crtc_atomic_disable(struct drm_crtc *crtc,
445 				     struct drm_crtc_state *old_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 LTDC */
455 	reg_clear(ldev->regs, LTDC_GCR, GCR_LTDCEN);
456 
457 	/* disable IRQ */
458 	reg_clear(ldev->regs, LTDC_IER, IER_RRIE | IER_FUIE | IER_TERRIE);
459 
460 	/* immediately commit disable of layers before switching off LTDC */
461 	reg_set(ldev->regs, LTDC_SRCR, SRCR_IMR);
462 
463 	pm_runtime_put_sync(ddev->dev);
464 }
465 
466 #define CLK_TOLERANCE_HZ 50
467 
468 static enum drm_mode_status
469 ltdc_crtc_mode_valid(struct drm_crtc *crtc,
470 		     const struct drm_display_mode *mode)
471 {
472 	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
473 	int target = mode->clock * 1000;
474 	int target_min = target - CLK_TOLERANCE_HZ;
475 	int target_max = target + CLK_TOLERANCE_HZ;
476 	int result;
477 
478 	result = clk_round_rate(ldev->pixel_clk, target);
479 
480 	DRM_DEBUG_DRIVER("clk rate target %d, available %d\n", target, result);
481 
482 	/* Filter modes according to the max frequency supported by the pads */
483 	if (result > ldev->caps.pad_max_freq_hz)
484 		return MODE_CLOCK_HIGH;
485 
486 	/*
487 	 * Accept all "preferred" modes:
488 	 * - this is important for panels because panel clock tolerances are
489 	 *   bigger than hdmi ones and there is no reason to not accept them
490 	 *   (the fps may vary a little but it is not a problem).
491 	 * - the hdmi preferred mode will be accepted too, but userland will
492 	 *   be able to use others hdmi "valid" modes if necessary.
493 	 */
494 	if (mode->type & DRM_MODE_TYPE_PREFERRED)
495 		return MODE_OK;
496 
497 	/*
498 	 * Filter modes according to the clock value, particularly useful for
499 	 * hdmi modes that require precise pixel clocks.
500 	 */
501 	if (result < target_min || result > target_max)
502 		return MODE_CLOCK_RANGE;
503 
504 	return MODE_OK;
505 }
506 
507 static bool ltdc_crtc_mode_fixup(struct drm_crtc *crtc,
508 				 const struct drm_display_mode *mode,
509 				 struct drm_display_mode *adjusted_mode)
510 {
511 	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
512 	struct drm_device *ddev = crtc->dev;
513 	int rate = mode->clock * 1000;
514 	bool runtime_active;
515 	int ret;
516 
517 	runtime_active = pm_runtime_active(ddev->dev);
518 
519 	if (runtime_active)
520 		pm_runtime_put_sync(ddev->dev);
521 
522 	if (clk_set_rate(ldev->pixel_clk, rate) < 0) {
523 		DRM_ERROR("Cannot set rate (%dHz) for pixel clk\n", rate);
524 		return false;
525 	}
526 
527 	adjusted_mode->clock = clk_get_rate(ldev->pixel_clk) / 1000;
528 
529 	if (runtime_active) {
530 		ret = pm_runtime_get_sync(ddev->dev);
531 		if (ret) {
532 			DRM_ERROR("Failed to fixup mode, cannot get sync\n");
533 			return false;
534 		}
535 	}
536 
537 	DRM_DEBUG_DRIVER("requested clock %dkHz, adjusted clock %dkHz\n",
538 			 mode->clock, adjusted_mode->clock);
539 
540 	return true;
541 }
542 
543 static void ltdc_crtc_mode_set_nofb(struct drm_crtc *crtc)
544 {
545 	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
546 	struct drm_device *ddev = crtc->dev;
547 	struct drm_display_mode *mode = &crtc->state->adjusted_mode;
548 	struct videomode vm;
549 	u32 hsync, vsync, accum_hbp, accum_vbp, accum_act_w, accum_act_h;
550 	u32 total_width, total_height;
551 	u32 val;
552 	int ret;
553 
554 	if (!pm_runtime_active(ddev->dev)) {
555 		ret = pm_runtime_get_sync(ddev->dev);
556 		if (ret) {
557 			DRM_ERROR("Failed to set mode, cannot get sync\n");
558 			return;
559 		}
560 	}
561 
562 	drm_display_mode_to_videomode(mode, &vm);
563 
564 	DRM_DEBUG_DRIVER("CRTC:%d mode:%s\n", crtc->base.id, mode->name);
565 	DRM_DEBUG_DRIVER("Video mode: %dx%d", vm.hactive, vm.vactive);
566 	DRM_DEBUG_DRIVER(" hfp %d hbp %d hsl %d vfp %d vbp %d vsl %d\n",
567 			 vm.hfront_porch, vm.hback_porch, vm.hsync_len,
568 			 vm.vfront_porch, vm.vback_porch, vm.vsync_len);
569 
570 	/* Convert video timings to ltdc timings */
571 	hsync = vm.hsync_len - 1;
572 	vsync = vm.vsync_len - 1;
573 	accum_hbp = hsync + vm.hback_porch;
574 	accum_vbp = vsync + vm.vback_porch;
575 	accum_act_w = accum_hbp + vm.hactive;
576 	accum_act_h = accum_vbp + vm.vactive;
577 	total_width = accum_act_w + vm.hfront_porch;
578 	total_height = accum_act_h + vm.vfront_porch;
579 
580 	/* Configures the HS, VS, DE and PC polarities. Default Active Low */
581 	val = 0;
582 
583 	if (vm.flags & DISPLAY_FLAGS_HSYNC_HIGH)
584 		val |= GCR_HSPOL;
585 
586 	if (vm.flags & DISPLAY_FLAGS_VSYNC_HIGH)
587 		val |= GCR_VSPOL;
588 
589 	if (vm.flags & DISPLAY_FLAGS_DE_LOW)
590 		val |= GCR_DEPOL;
591 
592 	if (vm.flags & DISPLAY_FLAGS_PIXDATA_NEGEDGE)
593 		val |= GCR_PCPOL;
594 
595 	reg_update_bits(ldev->regs, LTDC_GCR,
596 			GCR_HSPOL | GCR_VSPOL | GCR_DEPOL | GCR_PCPOL, val);
597 
598 	/* Set Synchronization size */
599 	val = (hsync << 16) | vsync;
600 	reg_update_bits(ldev->regs, LTDC_SSCR, SSCR_VSH | SSCR_HSW, val);
601 
602 	/* Set Accumulated Back porch */
603 	val = (accum_hbp << 16) | accum_vbp;
604 	reg_update_bits(ldev->regs, LTDC_BPCR, BPCR_AVBP | BPCR_AHBP, val);
605 
606 	/* Set Accumulated Active Width */
607 	val = (accum_act_w << 16) | accum_act_h;
608 	reg_update_bits(ldev->regs, LTDC_AWCR, AWCR_AAW | AWCR_AAH, val);
609 
610 	/* Set total width & height */
611 	val = (total_width << 16) | total_height;
612 	reg_update_bits(ldev->regs, LTDC_TWCR, TWCR_TOTALH | TWCR_TOTALW, val);
613 
614 	reg_write(ldev->regs, LTDC_LIPCR, (accum_act_h + 1));
615 }
616 
617 static void ltdc_crtc_atomic_flush(struct drm_crtc *crtc,
618 				   struct drm_crtc_state *old_crtc_state)
619 {
620 	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
621 	struct drm_device *ddev = crtc->dev;
622 	struct drm_pending_vblank_event *event = crtc->state->event;
623 
624 	DRM_DEBUG_ATOMIC("\n");
625 
626 	ltdc_crtc_update_clut(crtc);
627 
628 	/* Commit shadow registers = update planes at next vblank */
629 	reg_set(ldev->regs, LTDC_SRCR, SRCR_VBR);
630 
631 	if (event) {
632 		crtc->state->event = NULL;
633 
634 		spin_lock_irq(&ddev->event_lock);
635 		if (drm_crtc_vblank_get(crtc) == 0)
636 			drm_crtc_arm_vblank_event(crtc, event);
637 		else
638 			drm_crtc_send_vblank_event(crtc, event);
639 		spin_unlock_irq(&ddev->event_lock);
640 	}
641 }
642 
643 static const struct drm_crtc_helper_funcs ltdc_crtc_helper_funcs = {
644 	.mode_valid = ltdc_crtc_mode_valid,
645 	.mode_fixup = ltdc_crtc_mode_fixup,
646 	.mode_set_nofb = ltdc_crtc_mode_set_nofb,
647 	.atomic_flush = ltdc_crtc_atomic_flush,
648 	.atomic_enable = ltdc_crtc_atomic_enable,
649 	.atomic_disable = ltdc_crtc_atomic_disable,
650 };
651 
652 static int ltdc_crtc_enable_vblank(struct drm_crtc *crtc)
653 {
654 	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
655 
656 	DRM_DEBUG_DRIVER("\n");
657 	reg_set(ldev->regs, LTDC_IER, IER_LIE);
658 
659 	return 0;
660 }
661 
662 static void ltdc_crtc_disable_vblank(struct drm_crtc *crtc)
663 {
664 	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
665 
666 	DRM_DEBUG_DRIVER("\n");
667 	reg_clear(ldev->regs, LTDC_IER, IER_LIE);
668 }
669 
670 bool ltdc_crtc_scanoutpos(struct drm_device *ddev, unsigned int pipe,
671 			  bool in_vblank_irq, int *vpos, int *hpos,
672 			  ktime_t *stime, ktime_t *etime,
673 			  const struct drm_display_mode *mode)
674 {
675 	struct ltdc_device *ldev = ddev->dev_private;
676 	int line, vactive_start, vactive_end, vtotal;
677 
678 	if (stime)
679 		*stime = ktime_get();
680 
681 	/* The active area starts after vsync + front porch and ends
682 	 * at vsync + front porc + display size.
683 	 * The total height also include back porch.
684 	 * We have 3 possible cases to handle:
685 	 * - line < vactive_start: vpos = line - vactive_start and will be
686 	 * negative
687 	 * - vactive_start < line < vactive_end: vpos = line - vactive_start
688 	 * and will be positive
689 	 * - line > vactive_end: vpos = line - vtotal - vactive_start
690 	 * and will negative
691 	 *
692 	 * Computation for the two first cases are identical so we can
693 	 * simplify the code and only test if line > vactive_end
694 	 */
695 	if (pm_runtime_active(ddev->dev)) {
696 		line = reg_read(ldev->regs, LTDC_CPSR) & CPSR_CYPOS;
697 		vactive_start = reg_read(ldev->regs, LTDC_BPCR) & BPCR_AVBP;
698 		vactive_end = reg_read(ldev->regs, LTDC_AWCR) & AWCR_AAH;
699 		vtotal = reg_read(ldev->regs, LTDC_TWCR) & TWCR_TOTALH;
700 
701 		if (line > vactive_end)
702 			*vpos = line - vtotal - vactive_start;
703 		else
704 			*vpos = line - vactive_start;
705 	} else {
706 		*vpos = 0;
707 	}
708 
709 	*hpos = 0;
710 
711 	if (etime)
712 		*etime = ktime_get();
713 
714 	return true;
715 }
716 
717 static const struct drm_crtc_funcs ltdc_crtc_funcs = {
718 	.destroy = drm_crtc_cleanup,
719 	.set_config = drm_atomic_helper_set_config,
720 	.page_flip = drm_atomic_helper_page_flip,
721 	.reset = drm_atomic_helper_crtc_reset,
722 	.atomic_duplicate_state = drm_atomic_helper_crtc_duplicate_state,
723 	.atomic_destroy_state = drm_atomic_helper_crtc_destroy_state,
724 	.enable_vblank = ltdc_crtc_enable_vblank,
725 	.disable_vblank = ltdc_crtc_disable_vblank,
726 	.gamma_set = drm_atomic_helper_legacy_gamma_set,
727 };
728 
729 /*
730  * DRM_PLANE
731  */
732 
733 static int ltdc_plane_atomic_check(struct drm_plane *plane,
734 				   struct drm_plane_state *state)
735 {
736 	struct drm_framebuffer *fb = state->fb;
737 	u32 src_w, src_h;
738 
739 	DRM_DEBUG_DRIVER("\n");
740 
741 	if (!fb)
742 		return 0;
743 
744 	/* convert src_ from 16:16 format */
745 	src_w = state->src_w >> 16;
746 	src_h = state->src_h >> 16;
747 
748 	/* Reject scaling */
749 	if (src_w != state->crtc_w || src_h != state->crtc_h) {
750 		DRM_ERROR("Scaling is not supported");
751 		return -EINVAL;
752 	}
753 
754 	return 0;
755 }
756 
757 static void ltdc_plane_atomic_update(struct drm_plane *plane,
758 				     struct drm_plane_state *oldstate)
759 {
760 	struct ltdc_device *ldev = plane_to_ltdc(plane);
761 	struct drm_plane_state *state = plane->state;
762 	struct drm_framebuffer *fb = state->fb;
763 	u32 lofs = plane->index * LAY_OFS;
764 	u32 x0 = state->crtc_x;
765 	u32 x1 = state->crtc_x + state->crtc_w - 1;
766 	u32 y0 = state->crtc_y;
767 	u32 y1 = state->crtc_y + state->crtc_h - 1;
768 	u32 src_x, src_y, src_w, src_h;
769 	u32 val, pitch_in_bytes, line_length, paddr, ahbp, avbp, bpcr;
770 	enum ltdc_pix_fmt pf;
771 
772 	if (!state->crtc || !fb) {
773 		DRM_DEBUG_DRIVER("fb or crtc NULL");
774 		return;
775 	}
776 
777 	/* convert src_ from 16:16 format */
778 	src_x = state->src_x >> 16;
779 	src_y = state->src_y >> 16;
780 	src_w = state->src_w >> 16;
781 	src_h = state->src_h >> 16;
782 
783 	DRM_DEBUG_DRIVER("plane:%d fb:%d (%dx%d)@(%d,%d) -> (%dx%d)@(%d,%d)\n",
784 			 plane->base.id, fb->base.id,
785 			 src_w, src_h, src_x, src_y,
786 			 state->crtc_w, state->crtc_h,
787 			 state->crtc_x, state->crtc_y);
788 
789 	bpcr = reg_read(ldev->regs, LTDC_BPCR);
790 	ahbp = (bpcr & BPCR_AHBP) >> 16;
791 	avbp = bpcr & BPCR_AVBP;
792 
793 	/* Configures the horizontal start and stop position */
794 	val = ((x1 + 1 + ahbp) << 16) + (x0 + 1 + ahbp);
795 	reg_update_bits(ldev->regs, LTDC_L1WHPCR + lofs,
796 			LXWHPCR_WHSTPOS | LXWHPCR_WHSPPOS, val);
797 
798 	/* Configures the vertical start and stop position */
799 	val = ((y1 + 1 + avbp) << 16) + (y0 + 1 + avbp);
800 	reg_update_bits(ldev->regs, LTDC_L1WVPCR + lofs,
801 			LXWVPCR_WVSTPOS | LXWVPCR_WVSPPOS, val);
802 
803 	/* Specifies the pixel format */
804 	pf = to_ltdc_pixelformat(fb->format->format);
805 	for (val = 0; val < NB_PF; val++)
806 		if (ldev->caps.pix_fmt_hw[val] == pf)
807 			break;
808 
809 	if (val == NB_PF) {
810 		DRM_ERROR("Pixel format %.4s not supported\n",
811 			  (char *)&fb->format->format);
812 		val = 0;	/* set by default ARGB 32 bits */
813 	}
814 	reg_update_bits(ldev->regs, LTDC_L1PFCR + lofs, LXPFCR_PF, val);
815 
816 	/* Configures the color frame buffer pitch in bytes & line length */
817 	pitch_in_bytes = fb->pitches[0];
818 	line_length = fb->format->cpp[0] *
819 		      (x1 - x0 + 1) + (ldev->caps.bus_width >> 3) - 1;
820 	val = ((pitch_in_bytes << 16) | line_length);
821 	reg_update_bits(ldev->regs, LTDC_L1CFBLR + lofs,
822 			LXCFBLR_CFBLL | LXCFBLR_CFBP, val);
823 
824 	/* Specifies the constant alpha value */
825 	val = CONSTA_MAX;
826 	reg_update_bits(ldev->regs, LTDC_L1CACR + lofs, LXCACR_CONSTA, val);
827 
828 	/* Specifies the blending factors */
829 	val = BF1_PAXCA | BF2_1PAXCA;
830 	if (!fb->format->has_alpha)
831 		val = BF1_CA | BF2_1CA;
832 
833 	/* Manage hw-specific capabilities */
834 	if (ldev->caps.non_alpha_only_l1 &&
835 	    plane->type != DRM_PLANE_TYPE_PRIMARY)
836 		val = BF1_PAXCA | BF2_1PAXCA;
837 
838 	reg_update_bits(ldev->regs, LTDC_L1BFCR + lofs,
839 			LXBFCR_BF2 | LXBFCR_BF1, val);
840 
841 	/* Configures the frame buffer line number */
842 	val = y1 - y0 + 1;
843 	reg_update_bits(ldev->regs, LTDC_L1CFBLNR + lofs, LXCFBLNR_CFBLN, val);
844 
845 	/* Sets the FB address */
846 	paddr = (u32)drm_fb_cma_get_gem_addr(fb, state, 0);
847 
848 	DRM_DEBUG_DRIVER("fb: phys 0x%08x", paddr);
849 	reg_write(ldev->regs, LTDC_L1CFBAR + lofs, paddr);
850 
851 	/* Enable layer and CLUT if needed */
852 	val = fb->format->format == DRM_FORMAT_C8 ? LXCR_CLUTEN : 0;
853 	val |= LXCR_LEN;
854 	reg_update_bits(ldev->regs, LTDC_L1CR + lofs,
855 			LXCR_LEN | LXCR_CLUTEN, val);
856 
857 	ldev->plane_fpsi[plane->index].counter++;
858 
859 	mutex_lock(&ldev->err_lock);
860 	if (ldev->error_status & ISR_FUIF) {
861 		DRM_WARN("ltdc fifo underrun: please verify display mode\n");
862 		ldev->error_status &= ~ISR_FUIF;
863 	}
864 	if (ldev->error_status & ISR_TERRIF) {
865 		DRM_WARN("ltdc transfer error\n");
866 		ldev->error_status &= ~ISR_TERRIF;
867 	}
868 	mutex_unlock(&ldev->err_lock);
869 }
870 
871 static void ltdc_plane_atomic_disable(struct drm_plane *plane,
872 				      struct drm_plane_state *oldstate)
873 {
874 	struct ltdc_device *ldev = plane_to_ltdc(plane);
875 	u32 lofs = plane->index * LAY_OFS;
876 
877 	/* disable layer */
878 	reg_clear(ldev->regs, LTDC_L1CR + lofs, LXCR_LEN);
879 
880 	DRM_DEBUG_DRIVER("CRTC:%d plane:%d\n",
881 			 oldstate->crtc->base.id, plane->base.id);
882 }
883 
884 static void ltdc_plane_atomic_print_state(struct drm_printer *p,
885 					  const struct drm_plane_state *state)
886 {
887 	struct drm_plane *plane = state->plane;
888 	struct ltdc_device *ldev = plane_to_ltdc(plane);
889 	struct fps_info *fpsi = &ldev->plane_fpsi[plane->index];
890 	int ms_since_last;
891 	ktime_t now;
892 
893 	now = ktime_get();
894 	ms_since_last = ktime_to_ms(ktime_sub(now, fpsi->last_timestamp));
895 
896 	drm_printf(p, "\tuser_updates=%dfps\n",
897 		   DIV_ROUND_CLOSEST(fpsi->counter * 1000, ms_since_last));
898 
899 	fpsi->last_timestamp = now;
900 	fpsi->counter = 0;
901 }
902 
903 static bool ltdc_plane_format_mod_supported(struct drm_plane *plane,
904 					    u32 format,
905 					    u64 modifier)
906 {
907 	if (modifier == DRM_FORMAT_MOD_LINEAR)
908 		return true;
909 
910 	return false;
911 }
912 
913 static const struct drm_plane_funcs ltdc_plane_funcs = {
914 	.update_plane = drm_atomic_helper_update_plane,
915 	.disable_plane = drm_atomic_helper_disable_plane,
916 	.destroy = drm_plane_cleanup,
917 	.reset = drm_atomic_helper_plane_reset,
918 	.atomic_duplicate_state = drm_atomic_helper_plane_duplicate_state,
919 	.atomic_destroy_state = drm_atomic_helper_plane_destroy_state,
920 	.atomic_print_state = ltdc_plane_atomic_print_state,
921 	.format_mod_supported = ltdc_plane_format_mod_supported,
922 };
923 
924 static const struct drm_plane_helper_funcs ltdc_plane_helper_funcs = {
925 	.atomic_check = ltdc_plane_atomic_check,
926 	.atomic_update = ltdc_plane_atomic_update,
927 	.atomic_disable = ltdc_plane_atomic_disable,
928 };
929 
930 static struct drm_plane *ltdc_plane_create(struct drm_device *ddev,
931 					   enum drm_plane_type type)
932 {
933 	unsigned long possible_crtcs = CRTC_MASK;
934 	struct ltdc_device *ldev = ddev->dev_private;
935 	struct device *dev = ddev->dev;
936 	struct drm_plane *plane;
937 	unsigned int i, nb_fmt = 0;
938 	u32 formats[NB_PF * 2];
939 	u32 drm_fmt, drm_fmt_no_alpha;
940 	const u64 *modifiers = ltdc_format_modifiers;
941 	int ret;
942 
943 	/* Get supported pixel formats */
944 	for (i = 0; i < NB_PF; i++) {
945 		drm_fmt = to_drm_pixelformat(ldev->caps.pix_fmt_hw[i]);
946 		if (!drm_fmt)
947 			continue;
948 		formats[nb_fmt++] = drm_fmt;
949 
950 		/* Add the no-alpha related format if any & supported */
951 		drm_fmt_no_alpha = get_pixelformat_without_alpha(drm_fmt);
952 		if (!drm_fmt_no_alpha)
953 			continue;
954 
955 		/* Manage hw-specific capabilities */
956 		if (ldev->caps.non_alpha_only_l1 &&
957 		    type != DRM_PLANE_TYPE_PRIMARY)
958 			continue;
959 
960 		formats[nb_fmt++] = drm_fmt_no_alpha;
961 	}
962 
963 	plane = devm_kzalloc(dev, sizeof(*plane), GFP_KERNEL);
964 	if (!plane)
965 		return NULL;
966 
967 	ret = drm_universal_plane_init(ddev, plane, possible_crtcs,
968 				       &ltdc_plane_funcs, formats, nb_fmt,
969 				       modifiers, type, NULL);
970 	if (ret < 0)
971 		return NULL;
972 
973 	drm_plane_helper_add(plane, &ltdc_plane_helper_funcs);
974 
975 	DRM_DEBUG_DRIVER("plane:%d created\n", plane->base.id);
976 
977 	return plane;
978 }
979 
980 static void ltdc_plane_destroy_all(struct drm_device *ddev)
981 {
982 	struct drm_plane *plane, *plane_temp;
983 
984 	list_for_each_entry_safe(plane, plane_temp,
985 				 &ddev->mode_config.plane_list, head)
986 		drm_plane_cleanup(plane);
987 }
988 
989 static int ltdc_crtc_init(struct drm_device *ddev, struct drm_crtc *crtc)
990 {
991 	struct ltdc_device *ldev = ddev->dev_private;
992 	struct drm_plane *primary, *overlay;
993 	unsigned int i;
994 	int ret;
995 
996 	primary = ltdc_plane_create(ddev, DRM_PLANE_TYPE_PRIMARY);
997 	if (!primary) {
998 		DRM_ERROR("Can not create primary plane\n");
999 		return -EINVAL;
1000 	}
1001 
1002 	ret = drm_crtc_init_with_planes(ddev, crtc, primary, NULL,
1003 					&ltdc_crtc_funcs, NULL);
1004 	if (ret) {
1005 		DRM_ERROR("Can not initialize CRTC\n");
1006 		goto cleanup;
1007 	}
1008 
1009 	drm_crtc_helper_add(crtc, &ltdc_crtc_helper_funcs);
1010 
1011 	drm_mode_crtc_set_gamma_size(crtc, CLUT_SIZE);
1012 	drm_crtc_enable_color_mgmt(crtc, 0, false, CLUT_SIZE);
1013 
1014 	DRM_DEBUG_DRIVER("CRTC:%d created\n", crtc->base.id);
1015 
1016 	/* Add planes. Note : the first layer is used by primary plane */
1017 	for (i = 1; i < ldev->caps.nb_layers; i++) {
1018 		overlay = ltdc_plane_create(ddev, DRM_PLANE_TYPE_OVERLAY);
1019 		if (!overlay) {
1020 			ret = -ENOMEM;
1021 			DRM_ERROR("Can not create overlay plane %d\n", i);
1022 			goto cleanup;
1023 		}
1024 	}
1025 
1026 	return 0;
1027 
1028 cleanup:
1029 	ltdc_plane_destroy_all(ddev);
1030 	return ret;
1031 }
1032 
1033 /*
1034  * DRM_ENCODER
1035  */
1036 
1037 static const struct drm_encoder_funcs ltdc_encoder_funcs = {
1038 	.destroy = drm_encoder_cleanup,
1039 };
1040 
1041 static int ltdc_encoder_init(struct drm_device *ddev, struct drm_bridge *bridge)
1042 {
1043 	struct drm_encoder *encoder;
1044 	int ret;
1045 
1046 	encoder = devm_kzalloc(ddev->dev, sizeof(*encoder), GFP_KERNEL);
1047 	if (!encoder)
1048 		return -ENOMEM;
1049 
1050 	encoder->possible_crtcs = CRTC_MASK;
1051 	encoder->possible_clones = 0;	/* No cloning support */
1052 
1053 	drm_encoder_init(ddev, encoder, &ltdc_encoder_funcs,
1054 			 DRM_MODE_ENCODER_DPI, NULL);
1055 
1056 	ret = drm_bridge_attach(encoder, bridge, NULL);
1057 	if (ret) {
1058 		drm_encoder_cleanup(encoder);
1059 		return -EINVAL;
1060 	}
1061 
1062 	DRM_DEBUG_DRIVER("Bridge encoder:%d created\n", encoder->base.id);
1063 
1064 	return 0;
1065 }
1066 
1067 static int ltdc_get_caps(struct drm_device *ddev)
1068 {
1069 	struct ltdc_device *ldev = ddev->dev_private;
1070 	u32 bus_width_log2, lcr, gc2r;
1071 
1072 	/*
1073 	 * at least 1 layer must be managed & the number of layers
1074 	 * must not exceed LTDC_MAX_LAYER
1075 	 */
1076 	lcr = reg_read(ldev->regs, LTDC_LCR);
1077 
1078 	ldev->caps.nb_layers = clamp((int)lcr, 1, LTDC_MAX_LAYER);
1079 
1080 	/* set data bus width */
1081 	gc2r = reg_read(ldev->regs, LTDC_GC2R);
1082 	bus_width_log2 = (gc2r & GC2R_BW) >> 4;
1083 	ldev->caps.bus_width = 8 << bus_width_log2;
1084 	ldev->caps.hw_version = reg_read(ldev->regs, LTDC_IDR);
1085 
1086 	switch (ldev->caps.hw_version) {
1087 	case HWVER_10200:
1088 	case HWVER_10300:
1089 		ldev->caps.reg_ofs = REG_OFS_NONE;
1090 		ldev->caps.pix_fmt_hw = ltdc_pix_fmt_a0;
1091 		/*
1092 		 * Hw older versions support non-alpha color formats derived
1093 		 * from native alpha color formats only on the primary layer.
1094 		 * For instance, RG16 native format without alpha works fine
1095 		 * on 2nd layer but XR24 (derived color format from AR24)
1096 		 * does not work on 2nd layer.
1097 		 */
1098 		ldev->caps.non_alpha_only_l1 = true;
1099 		ldev->caps.pad_max_freq_hz = 90000000;
1100 		if (ldev->caps.hw_version == HWVER_10200)
1101 			ldev->caps.pad_max_freq_hz = 65000000;
1102 		break;
1103 	case HWVER_20101:
1104 		ldev->caps.reg_ofs = REG_OFS_4;
1105 		ldev->caps.pix_fmt_hw = ltdc_pix_fmt_a1;
1106 		ldev->caps.non_alpha_only_l1 = false;
1107 		ldev->caps.pad_max_freq_hz = 150000000;
1108 		break;
1109 	default:
1110 		return -ENODEV;
1111 	}
1112 
1113 	return 0;
1114 }
1115 
1116 void ltdc_suspend(struct drm_device *ddev)
1117 {
1118 	struct ltdc_device *ldev = ddev->dev_private;
1119 
1120 	DRM_DEBUG_DRIVER("\n");
1121 	clk_disable_unprepare(ldev->pixel_clk);
1122 }
1123 
1124 int ltdc_resume(struct drm_device *ddev)
1125 {
1126 	struct ltdc_device *ldev = ddev->dev_private;
1127 	int ret;
1128 
1129 	DRM_DEBUG_DRIVER("\n");
1130 
1131 	ret = clk_prepare_enable(ldev->pixel_clk);
1132 	if (ret) {
1133 		DRM_ERROR("failed to enable pixel clock (%d)\n", ret);
1134 		return ret;
1135 	}
1136 
1137 	return 0;
1138 }
1139 
1140 int ltdc_load(struct drm_device *ddev)
1141 {
1142 	struct platform_device *pdev = to_platform_device(ddev->dev);
1143 	struct ltdc_device *ldev = ddev->dev_private;
1144 	struct device *dev = ddev->dev;
1145 	struct device_node *np = dev->of_node;
1146 	struct drm_bridge *bridge[MAX_ENDPOINTS] = {NULL};
1147 	struct drm_panel *panel[MAX_ENDPOINTS] = {NULL};
1148 	struct drm_crtc *crtc;
1149 	struct reset_control *rstc;
1150 	struct resource *res;
1151 	int irq, ret, i, endpoint_not_ready = -ENODEV;
1152 
1153 	DRM_DEBUG_DRIVER("\n");
1154 
1155 	/* Get endpoints if any */
1156 	for (i = 0; i < MAX_ENDPOINTS; i++) {
1157 		ret = drm_of_find_panel_or_bridge(np, 0, i, &panel[i],
1158 						  &bridge[i]);
1159 
1160 		/*
1161 		 * If at least one endpoint is -EPROBE_DEFER, defer probing,
1162 		 * else if at least one endpoint is ready, continue probing.
1163 		 */
1164 		if (ret == -EPROBE_DEFER)
1165 			return ret;
1166 		else if (!ret)
1167 			endpoint_not_ready = 0;
1168 	}
1169 
1170 	if (endpoint_not_ready)
1171 		return endpoint_not_ready;
1172 
1173 	rstc = devm_reset_control_get_exclusive(dev, NULL);
1174 
1175 	mutex_init(&ldev->err_lock);
1176 
1177 	ldev->pixel_clk = devm_clk_get(dev, "lcd");
1178 	if (IS_ERR(ldev->pixel_clk)) {
1179 		if (PTR_ERR(ldev->pixel_clk) != -EPROBE_DEFER)
1180 			DRM_ERROR("Unable to get lcd clock\n");
1181 		return PTR_ERR(ldev->pixel_clk);
1182 	}
1183 
1184 	if (clk_prepare_enable(ldev->pixel_clk)) {
1185 		DRM_ERROR("Unable to prepare pixel clock\n");
1186 		return -ENODEV;
1187 	}
1188 
1189 	if (!IS_ERR(rstc)) {
1190 		reset_control_assert(rstc);
1191 		usleep_range(10, 20);
1192 		reset_control_deassert(rstc);
1193 	}
1194 
1195 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1196 	ldev->regs = devm_ioremap_resource(dev, res);
1197 	if (IS_ERR(ldev->regs)) {
1198 		DRM_ERROR("Unable to get ltdc registers\n");
1199 		ret = PTR_ERR(ldev->regs);
1200 		goto err;
1201 	}
1202 
1203 	/* Disable interrupts */
1204 	reg_clear(ldev->regs, LTDC_IER,
1205 		  IER_LIE | IER_RRIE | IER_FUIE | IER_TERRIE);
1206 
1207 	for (i = 0; i < MAX_IRQ; i++) {
1208 		irq = platform_get_irq(pdev, i);
1209 		if (irq == -EPROBE_DEFER)
1210 			goto err;
1211 
1212 		if (irq < 0)
1213 			continue;
1214 
1215 		ret = devm_request_threaded_irq(dev, irq, ltdc_irq,
1216 						ltdc_irq_thread, IRQF_ONESHOT,
1217 						dev_name(dev), ddev);
1218 		if (ret) {
1219 			DRM_ERROR("Failed to register LTDC interrupt\n");
1220 			goto err;
1221 		}
1222 	}
1223 
1224 
1225 	ret = ltdc_get_caps(ddev);
1226 	if (ret) {
1227 		DRM_ERROR("hardware identifier (0x%08x) not supported!\n",
1228 			  ldev->caps.hw_version);
1229 		goto err;
1230 	}
1231 
1232 	DRM_DEBUG_DRIVER("ltdc hw version 0x%08x\n", ldev->caps.hw_version);
1233 
1234 	/* Add endpoints panels or bridges if any */
1235 	for (i = 0; i < MAX_ENDPOINTS; i++) {
1236 		if (panel[i]) {
1237 			bridge[i] = drm_panel_bridge_add(panel[i],
1238 							DRM_MODE_CONNECTOR_DPI);
1239 			if (IS_ERR(bridge[i])) {
1240 				DRM_ERROR("panel-bridge endpoint %d\n", i);
1241 				ret = PTR_ERR(bridge[i]);
1242 				goto err;
1243 			}
1244 		}
1245 
1246 		if (bridge[i]) {
1247 			ret = ltdc_encoder_init(ddev, bridge[i]);
1248 			if (ret) {
1249 				DRM_ERROR("init encoder endpoint %d\n", i);
1250 				goto err;
1251 			}
1252 		}
1253 	}
1254 
1255 	crtc = devm_kzalloc(dev, sizeof(*crtc), GFP_KERNEL);
1256 	if (!crtc) {
1257 		DRM_ERROR("Failed to allocate crtc\n");
1258 		ret = -ENOMEM;
1259 		goto err;
1260 	}
1261 
1262 	ddev->mode_config.allow_fb_modifiers = true;
1263 
1264 	ret = ltdc_crtc_init(ddev, crtc);
1265 	if (ret) {
1266 		DRM_ERROR("Failed to init crtc\n");
1267 		goto err;
1268 	}
1269 
1270 	ret = drm_vblank_init(ddev, NB_CRTC);
1271 	if (ret) {
1272 		DRM_ERROR("Failed calling drm_vblank_init()\n");
1273 		goto err;
1274 	}
1275 
1276 	/* Allow usage of vblank without having to call drm_irq_install */
1277 	ddev->irq_enabled = 1;
1278 
1279 	clk_disable_unprepare(ldev->pixel_clk);
1280 
1281 	pm_runtime_enable(ddev->dev);
1282 
1283 	return 0;
1284 err:
1285 	for (i = 0; i < MAX_ENDPOINTS; i++)
1286 		drm_panel_bridge_remove(bridge[i]);
1287 
1288 	clk_disable_unprepare(ldev->pixel_clk);
1289 
1290 	return ret;
1291 }
1292 
1293 void ltdc_unload(struct drm_device *ddev)
1294 {
1295 	int i;
1296 
1297 	DRM_DEBUG_DRIVER("\n");
1298 
1299 	for (i = 0; i < MAX_ENDPOINTS; i++)
1300 		drm_of_panel_bridge_remove(ddev->dev->of_node, 0, i);
1301 
1302 	pm_runtime_disable(ddev->dev);
1303 }
1304 
1305 MODULE_AUTHOR("Philippe Cornu <philippe.cornu@st.com>");
1306 MODULE_AUTHOR("Yannick Fertre <yannick.fertre@st.com>");
1307 MODULE_AUTHOR("Fabien Dessenne <fabien.dessenne@st.com>");
1308 MODULE_AUTHOR("Mickael Reulier <mickael.reulier@st.com>");
1309 MODULE_DESCRIPTION("STMicroelectronics ST DRM LTDC driver");
1310 MODULE_LICENSE("GPL v2");
1311