1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (C) 2017-2018 STMicroelectronics - All Rights Reserved
4  * Author(s): Philippe Cornu <philippe.cornu@st.com> for STMicroelectronics.
5  *	      Yannick Fertre <yannick.fertre@st.com> for STMicroelectronics.
6  */
7 
8 #define LOG_CATEGORY UCLASS_VIDEO
9 
10 #include <common.h>
11 #include <clk.h>
12 #include <display.h>
13 #include <dm.h>
14 #include <log.h>
15 #include <panel.h>
16 #include <reset.h>
17 #include <video.h>
18 #include <video_bridge.h>
19 #include <asm/io.h>
20 #include <asm/arch/gpio.h>
21 #include <dm/device-internal.h>
22 #include <dm/device_compat.h>
23 #include <linux/bitops.h>
24 
25 struct stm32_ltdc_priv {
26 	void __iomem *regs;
27 	enum video_log2_bpp l2bpp;
28 	u32 bg_col_argb;
29 	u32 crop_x, crop_y, crop_w, crop_h;
30 	u32 alpha;
31 };
32 
33 /* LTDC main registers */
34 #define LTDC_IDR	0x00	/* IDentification */
35 #define LTDC_LCR	0x04	/* Layer Count */
36 #define LTDC_SSCR	0x08	/* Synchronization Size Configuration */
37 #define LTDC_BPCR	0x0C	/* Back Porch Configuration */
38 #define LTDC_AWCR	0x10	/* Active Width Configuration */
39 #define LTDC_TWCR	0x14	/* Total Width Configuration */
40 #define LTDC_GCR	0x18	/* Global Control */
41 #define LTDC_GC1R	0x1C	/* Global Configuration 1 */
42 #define LTDC_GC2R	0x20	/* Global Configuration 2 */
43 #define LTDC_SRCR	0x24	/* Shadow Reload Configuration */
44 #define LTDC_GACR	0x28	/* GAmma Correction */
45 #define LTDC_BCCR	0x2C	/* Background Color Configuration */
46 #define LTDC_IER	0x34	/* Interrupt Enable */
47 #define LTDC_ISR	0x38	/* Interrupt Status */
48 #define LTDC_ICR	0x3C	/* Interrupt Clear */
49 #define LTDC_LIPCR	0x40	/* Line Interrupt Position Conf. */
50 #define LTDC_CPSR	0x44	/* Current Position Status */
51 #define LTDC_CDSR	0x48	/* Current Display Status */
52 
53 /* LTDC layer 1 registers */
54 #define LTDC_L1LC1R	0x80	/* L1 Layer Configuration 1 */
55 #define LTDC_L1LC2R	0x84	/* L1 Layer Configuration 2 */
56 #define LTDC_L1CR	0x84	/* L1 Control */
57 #define LTDC_L1WHPCR	0x88	/* L1 Window Hor Position Config */
58 #define LTDC_L1WVPCR	0x8C	/* L1 Window Vert Position Config */
59 #define LTDC_L1CKCR	0x90	/* L1 Color Keying Configuration */
60 #define LTDC_L1PFCR	0x94	/* L1 Pixel Format Configuration */
61 #define LTDC_L1CACR	0x98	/* L1 Constant Alpha Config */
62 #define LTDC_L1DCCR	0x9C	/* L1 Default Color Configuration */
63 #define LTDC_L1BFCR	0xA0	/* L1 Blend Factors Configuration */
64 #define LTDC_L1FBBCR	0xA4	/* L1 FrameBuffer Bus Control */
65 #define LTDC_L1AFBCR	0xA8	/* L1 AuxFB Control */
66 #define LTDC_L1CFBAR	0xAC	/* L1 Color FrameBuffer Address */
67 #define LTDC_L1CFBLR	0xB0	/* L1 Color FrameBuffer Length */
68 #define LTDC_L1CFBLNR	0xB4	/* L1 Color FrameBuffer Line Nb */
69 #define LTDC_L1AFBAR	0xB8	/* L1 AuxFB Address */
70 #define LTDC_L1AFBLR	0xBC	/* L1 AuxFB Length */
71 #define LTDC_L1AFBLNR	0xC0	/* L1 AuxFB Line Number */
72 #define LTDC_L1CLUTWR	0xC4	/* L1 CLUT Write */
73 
74 /* Bit definitions */
75 #define SSCR_VSH	GENMASK(10, 0)	/* Vertical Synchronization Height */
76 #define SSCR_HSW	GENMASK(27, 16)	/* Horizontal Synchronization Width */
77 
78 #define BPCR_AVBP	GENMASK(10, 0)	/* Accumulated Vertical Back Porch */
79 #define BPCR_AHBP	GENMASK(27, 16)	/* Accumulated Horizontal Back Porch */
80 
81 #define AWCR_AAH	GENMASK(10, 0)	/* Accumulated Active Height */
82 #define AWCR_AAW	GENMASK(27, 16)	/* Accumulated Active Width */
83 
84 #define TWCR_TOTALH	GENMASK(10, 0)	/* TOTAL Height */
85 #define TWCR_TOTALW	GENMASK(27, 16)	/* TOTAL Width */
86 
87 #define GCR_LTDCEN	BIT(0)		/* LTDC ENable */
88 #define GCR_DEN		BIT(16)		/* Dither ENable */
89 #define GCR_PCPOL	BIT(28)		/* Pixel Clock POLarity-Inverted */
90 #define GCR_DEPOL	BIT(29)		/* Data Enable POLarity-High */
91 #define GCR_VSPOL	BIT(30)		/* Vertical Synchro POLarity-High */
92 #define GCR_HSPOL	BIT(31)		/* Horizontal Synchro POLarity-High */
93 
94 #define GC1R_WBCH	GENMASK(3, 0)	/* Width of Blue CHannel output */
95 #define GC1R_WGCH	GENMASK(7, 4)	/* Width of Green Channel output */
96 #define GC1R_WRCH	GENMASK(11, 8)	/* Width of Red Channel output */
97 #define GC1R_PBEN	BIT(12)		/* Precise Blending ENable */
98 #define GC1R_DT		GENMASK(15, 14)	/* Dithering Technique */
99 #define GC1R_GCT	GENMASK(19, 17)	/* Gamma Correction Technique */
100 #define GC1R_SHREN	BIT(21)		/* SHadow Registers ENabled */
101 #define GC1R_BCP	BIT(22)		/* Background Colour Programmable */
102 #define GC1R_BBEN	BIT(23)		/* Background Blending ENabled */
103 #define GC1R_LNIP	BIT(24)		/* Line Number IRQ Position */
104 #define GC1R_TP		BIT(25)		/* Timing Programmable */
105 #define GC1R_IPP	BIT(26)		/* IRQ Polarity Programmable */
106 #define GC1R_SPP	BIT(27)		/* Sync Polarity Programmable */
107 #define GC1R_DWP	BIT(28)		/* Dither Width Programmable */
108 #define GC1R_STREN	BIT(29)		/* STatus Registers ENabled */
109 #define GC1R_BMEN	BIT(31)		/* Blind Mode ENabled */
110 
111 #define GC2R_EDCA	BIT(0)		/* External Display Control Ability  */
112 #define GC2R_STSAEN	BIT(1)		/* Slave Timing Sync Ability ENabled */
113 #define GC2R_DVAEN	BIT(2)		/* Dual-View Ability ENabled */
114 #define GC2R_DPAEN	BIT(3)		/* Dual-Port Ability ENabled */
115 #define GC2R_BW		GENMASK(6, 4)	/* Bus Width (log2 of nb of bytes) */
116 #define GC2R_EDCEN	BIT(7)		/* External Display Control ENabled */
117 
118 #define SRCR_IMR	BIT(0)		/* IMmediate Reload */
119 #define SRCR_VBR	BIT(1)		/* Vertical Blanking Reload */
120 
121 #define LXCR_LEN	BIT(0)		/* Layer ENable */
122 #define LXCR_COLKEN	BIT(1)		/* Color Keying Enable */
123 #define LXCR_CLUTEN	BIT(4)		/* Color Look-Up Table ENable */
124 
125 #define LXWHPCR_WHSTPOS	GENMASK(11, 0)	/* Window Horizontal StarT POSition */
126 #define LXWHPCR_WHSPPOS	GENMASK(27, 16)	/* Window Horizontal StoP POSition */
127 
128 #define LXWVPCR_WVSTPOS	GENMASK(10, 0)	/* Window Vertical StarT POSition */
129 #define LXWVPCR_WVSPPOS	GENMASK(26, 16)	/* Window Vertical StoP POSition */
130 
131 #define LXPFCR_PF	GENMASK(2, 0)	/* Pixel Format */
132 
133 #define LXCACR_CONSTA	GENMASK(7, 0)	/* CONSTant Alpha */
134 
135 #define LXBFCR_BF2	GENMASK(2, 0)	/* Blending Factor 2 */
136 #define LXBFCR_BF1	GENMASK(10, 8)	/* Blending Factor 1 */
137 
138 #define LXCFBLR_CFBLL	GENMASK(12, 0)	/* Color Frame Buffer Line Length */
139 #define LXCFBLR_CFBP	GENMASK(28, 16)	/* Color Frame Buffer Pitch in bytes */
140 
141 #define LXCFBLNR_CFBLN	GENMASK(10, 0)	/* Color Frame Buffer Line Number */
142 
143 #define BF1_PAXCA	0x600		/* Pixel Alpha x Constant Alpha */
144 #define BF1_CA		0x400		/* Constant Alpha */
145 #define BF2_1PAXCA	0x007		/* 1 - (Pixel Alpha x Constant Alpha) */
146 #define BF2_1CA		0x005		/* 1 - Constant Alpha */
147 
148 enum stm32_ltdc_pix_fmt {
149 	PF_ARGB8888 = 0,
150 	PF_RGB888,
151 	PF_RGB565,
152 	PF_ARGB1555,
153 	PF_ARGB4444,
154 	PF_L8,
155 	PF_AL44,
156 	PF_AL88
157 };
158 
159 /* TODO add more color format support */
stm32_ltdc_get_pixel_format(enum video_log2_bpp l2bpp)160 static u32 stm32_ltdc_get_pixel_format(enum video_log2_bpp l2bpp)
161 {
162 	enum stm32_ltdc_pix_fmt pf;
163 
164 	switch (l2bpp) {
165 	case VIDEO_BPP16:
166 		pf = PF_RGB565;
167 		break;
168 
169 	case VIDEO_BPP32:
170 		pf = PF_ARGB8888;
171 		break;
172 
173 	case VIDEO_BPP8:
174 		pf = PF_L8;
175 		break;
176 
177 	case VIDEO_BPP1:
178 	case VIDEO_BPP2:
179 	case VIDEO_BPP4:
180 	default:
181 		log_warning("warning %dbpp not supported yet, %dbpp instead\n",
182 			    VNBITS(l2bpp), VNBITS(VIDEO_BPP16));
183 		pf = PF_RGB565;
184 		break;
185 	}
186 
187 	log_debug("%d bpp -> ltdc pf %d\n", VNBITS(l2bpp), pf);
188 
189 	return (u32)pf;
190 }
191 
has_alpha(u32 fmt)192 static bool has_alpha(u32 fmt)
193 {
194 	switch (fmt) {
195 	case PF_ARGB8888:
196 	case PF_ARGB1555:
197 	case PF_ARGB4444:
198 	case PF_AL44:
199 	case PF_AL88:
200 		return true;
201 	case PF_RGB888:
202 	case PF_RGB565:
203 	case PF_L8:
204 	default:
205 		return false;
206 	}
207 }
208 
stm32_ltdc_enable(struct stm32_ltdc_priv * priv)209 static void stm32_ltdc_enable(struct stm32_ltdc_priv *priv)
210 {
211 	/* Reload configuration immediately & enable LTDC */
212 	setbits_le32(priv->regs + LTDC_SRCR, SRCR_IMR);
213 	setbits_le32(priv->regs + LTDC_GCR, GCR_LTDCEN);
214 }
215 
stm32_ltdc_set_mode(struct stm32_ltdc_priv * priv,struct display_timing * timings)216 static void stm32_ltdc_set_mode(struct stm32_ltdc_priv *priv,
217 				struct display_timing *timings)
218 {
219 	void __iomem *regs = priv->regs;
220 	u32 hsync, vsync, acc_hbp, acc_vbp, acc_act_w, acc_act_h;
221 	u32 total_w, total_h;
222 	u32 val;
223 
224 	/* Convert video timings to ltdc timings */
225 	hsync = timings->hsync_len.typ - 1;
226 	vsync = timings->vsync_len.typ - 1;
227 	acc_hbp = hsync + timings->hback_porch.typ;
228 	acc_vbp = vsync + timings->vback_porch.typ;
229 	acc_act_w = acc_hbp + timings->hactive.typ;
230 	acc_act_h = acc_vbp + timings->vactive.typ;
231 	total_w = acc_act_w + timings->hfront_porch.typ;
232 	total_h = acc_act_h + timings->vfront_porch.typ;
233 
234 	/* Synchronization sizes */
235 	val = (hsync << 16) | vsync;
236 	clrsetbits_le32(regs + LTDC_SSCR, SSCR_VSH | SSCR_HSW, val);
237 
238 	/* Accumulated back porch */
239 	val = (acc_hbp << 16) | acc_vbp;
240 	clrsetbits_le32(regs + LTDC_BPCR, BPCR_AVBP | BPCR_AHBP, val);
241 
242 	/* Accumulated active width */
243 	val = (acc_act_w << 16) | acc_act_h;
244 	clrsetbits_le32(regs + LTDC_AWCR, AWCR_AAW | AWCR_AAH, val);
245 
246 	/* Total width & height */
247 	val = (total_w << 16) | total_h;
248 	clrsetbits_le32(regs + LTDC_TWCR, TWCR_TOTALH | TWCR_TOTALW, val);
249 
250 	setbits_le32(regs + LTDC_LIPCR, acc_act_h + 1);
251 
252 	/* Signal polarities */
253 	val = 0;
254 	log_debug("timing->flags 0x%08x\n", timings->flags);
255 	if (timings->flags & DISPLAY_FLAGS_HSYNC_HIGH)
256 		val |= GCR_HSPOL;
257 	if (timings->flags & DISPLAY_FLAGS_VSYNC_HIGH)
258 		val |= GCR_VSPOL;
259 	if (timings->flags & DISPLAY_FLAGS_DE_HIGH)
260 		val |= GCR_DEPOL;
261 	if (timings->flags & DISPLAY_FLAGS_PIXDATA_NEGEDGE)
262 		val |= GCR_PCPOL;
263 	clrsetbits_le32(regs + LTDC_GCR,
264 			GCR_HSPOL | GCR_VSPOL | GCR_DEPOL | GCR_PCPOL, val);
265 
266 	/* Overall background color */
267 	writel(priv->bg_col_argb, priv->regs + LTDC_BCCR);
268 }
269 
stm32_ltdc_set_layer1(struct stm32_ltdc_priv * priv,ulong fb_addr)270 static void stm32_ltdc_set_layer1(struct stm32_ltdc_priv *priv, ulong fb_addr)
271 {
272 	void __iomem *regs = priv->regs;
273 	u32 x0, x1, y0, y1;
274 	u32 pitch_in_bytes;
275 	u32 line_length;
276 	u32 bus_width;
277 	u32 val, tmp, bpp;
278 	u32 format;
279 
280 	x0 = priv->crop_x;
281 	x1 = priv->crop_x + priv->crop_w - 1;
282 	y0 = priv->crop_y;
283 	y1 = priv->crop_y + priv->crop_h - 1;
284 
285 	/* Horizontal start and stop position */
286 	tmp = (readl(regs + LTDC_BPCR) & BPCR_AHBP) >> 16;
287 	val = ((x1 + 1 + tmp) << 16) + (x0 + 1 + tmp);
288 	clrsetbits_le32(regs + LTDC_L1WHPCR, LXWHPCR_WHSTPOS | LXWHPCR_WHSPPOS,
289 			val);
290 
291 	/* Vertical start & stop position */
292 	tmp = readl(regs + LTDC_BPCR) & BPCR_AVBP;
293 	val = ((y1 + 1 + tmp) << 16) + (y0 + 1 + tmp);
294 	clrsetbits_le32(regs + LTDC_L1WVPCR, LXWVPCR_WVSTPOS | LXWVPCR_WVSPPOS,
295 			val);
296 
297 	/* Layer background color */
298 	writel(priv->bg_col_argb, regs + LTDC_L1DCCR);
299 
300 	/* Color frame buffer pitch in bytes & line length */
301 	bpp = VNBITS(priv->l2bpp);
302 	pitch_in_bytes = priv->crop_w * (bpp >> 3);
303 	bus_width = 8 << ((readl(regs + LTDC_GC2R) & GC2R_BW) >> 4);
304 	line_length = ((bpp >> 3) * priv->crop_w) + (bus_width >> 3) - 1;
305 	val = (pitch_in_bytes << 16) | line_length;
306 	clrsetbits_le32(regs + LTDC_L1CFBLR, LXCFBLR_CFBLL | LXCFBLR_CFBP, val);
307 
308 	/* Pixel format */
309 	format = stm32_ltdc_get_pixel_format(priv->l2bpp);
310 	clrsetbits_le32(regs + LTDC_L1PFCR, LXPFCR_PF, format);
311 
312 	/* Constant alpha value */
313 	clrsetbits_le32(regs + LTDC_L1CACR, LXCACR_CONSTA, priv->alpha);
314 
315 	/* Specifies the blending factors : with or without pixel alpha */
316 	/* Manage hw-specific capabilities */
317 	val = has_alpha(format) ? BF1_PAXCA | BF2_1PAXCA : BF1_CA | BF2_1CA;
318 
319 	/* Blending factors */
320 	clrsetbits_le32(regs + LTDC_L1BFCR, LXBFCR_BF2 | LXBFCR_BF1, val);
321 
322 	/* Frame buffer line number */
323 	clrsetbits_le32(regs + LTDC_L1CFBLNR, LXCFBLNR_CFBLN, priv->crop_h);
324 
325 	/* Frame buffer address */
326 	writel(fb_addr, regs + LTDC_L1CFBAR);
327 
328 	/* Enable layer 1 */
329 	setbits_le32(priv->regs + LTDC_L1CR, LXCR_LEN);
330 }
331 
stm32_ltdc_probe(struct udevice * dev)332 static int stm32_ltdc_probe(struct udevice *dev)
333 {
334 	struct video_uc_plat *uc_plat = dev_get_uclass_plat(dev);
335 	struct video_priv *uc_priv = dev_get_uclass_priv(dev);
336 	struct stm32_ltdc_priv *priv = dev_get_priv(dev);
337 	struct udevice *bridge = NULL;
338 	struct udevice *panel = NULL;
339 	struct display_timing timings;
340 	struct clk pclk;
341 	struct reset_ctl rst;
342 	int ret;
343 
344 	priv->regs = (void *)dev_read_addr(dev);
345 	if ((fdt_addr_t)priv->regs == FDT_ADDR_T_NONE) {
346 		dev_err(dev, "ltdc dt register address error\n");
347 		return -EINVAL;
348 	}
349 
350 	ret = clk_get_by_index(dev, 0, &pclk);
351 	if (ret) {
352 		dev_err(dev, "peripheral clock get error %d\n", ret);
353 		return ret;
354 	}
355 
356 	ret = clk_enable(&pclk);
357 	if (ret) {
358 		dev_err(dev, "peripheral clock enable error %d\n", ret);
359 		return ret;
360 	}
361 
362 	ret = uclass_first_device_err(UCLASS_PANEL, &panel);
363 	if (ret) {
364 		if (ret != -ENODEV)
365 			dev_err(dev, "panel device error %d\n", ret);
366 		return ret;
367 	}
368 
369 	ret = panel_get_display_timing(panel, &timings);
370 	if (ret) {
371 		ret = ofnode_decode_display_timing(dev_ofnode(panel),
372 						   0, &timings);
373 		if (ret) {
374 			dev_err(dev, "decode display timing error %d\n", ret);
375 			return ret;
376 		}
377 	}
378 
379 	ret = clk_set_rate(&pclk, timings.pixelclock.typ);
380 	if (ret)
381 		dev_warn(dev, "fail to set pixel clock %d hz\n",
382 			 timings.pixelclock.typ);
383 
384 	dev_dbg(dev, "Set pixel clock req %d hz get %ld hz\n",
385 		timings.pixelclock.typ, clk_get_rate(&pclk));
386 
387 	ret = reset_get_by_index(dev, 0, &rst);
388 	if (ret) {
389 		dev_err(dev, "missing ltdc hardware reset\n");
390 		return ret;
391 	}
392 
393 	/* Reset */
394 	reset_deassert(&rst);
395 
396 	if (IS_ENABLED(CONFIG_VIDEO_BRIDGE)) {
397 		ret = uclass_get_device(UCLASS_VIDEO_BRIDGE, 0, &bridge);
398 		if (ret)
399 			dev_dbg(dev,
400 				"No video bridge, or no backlight on bridge\n");
401 
402 		if (bridge) {
403 			ret = video_bridge_attach(bridge);
404 			if (ret) {
405 				dev_err(bridge, "fail to attach bridge\n");
406 				return ret;
407 			}
408 		}
409 	}
410 
411 	/* TODO Below parameters are hard-coded for the moment... */
412 	priv->l2bpp = VIDEO_BPP16;
413 	priv->bg_col_argb = 0xFFFFFFFF; /* white no transparency */
414 	priv->crop_x = 0;
415 	priv->crop_y = 0;
416 	priv->crop_w = timings.hactive.typ;
417 	priv->crop_h = timings.vactive.typ;
418 	priv->alpha = 0xFF;
419 
420 	dev_dbg(dev, "%dx%d %dbpp frame buffer at 0x%lx\n",
421 		timings.hactive.typ, timings.vactive.typ,
422 		VNBITS(priv->l2bpp), uc_plat->base);
423 	dev_dbg(dev, "crop %d,%d %dx%d bg 0x%08x alpha %d\n",
424 		priv->crop_x, priv->crop_y, priv->crop_w, priv->crop_h,
425 		priv->bg_col_argb, priv->alpha);
426 
427 	/* Configure & start LTDC */
428 	stm32_ltdc_set_mode(priv, &timings);
429 	stm32_ltdc_set_layer1(priv, uc_plat->base);
430 	stm32_ltdc_enable(priv);
431 
432 	uc_priv->xsize = timings.hactive.typ;
433 	uc_priv->ysize = timings.vactive.typ;
434 	uc_priv->bpix = priv->l2bpp;
435 
436 	if (!bridge) {
437 		ret = panel_enable_backlight(panel);
438 		if (ret) {
439 			dev_err(dev, "panel %s enable backlight error %d\n",
440 				panel->name, ret);
441 			return ret;
442 		}
443 	} else if (IS_ENABLED(CONFIG_VIDEO_BRIDGE)) {
444 		ret = video_bridge_set_backlight(bridge, 80);
445 		if (ret) {
446 			dev_err(dev, "fail to set backlight\n");
447 			return ret;
448 		}
449 	}
450 
451 	video_set_flush_dcache(dev, true);
452 
453 	return 0;
454 }
455 
stm32_ltdc_bind(struct udevice * dev)456 static int stm32_ltdc_bind(struct udevice *dev)
457 {
458 	struct video_uc_plat *uc_plat = dev_get_uclass_plat(dev);
459 
460 	uc_plat->size = CONFIG_VIDEO_STM32_MAX_XRES *
461 			CONFIG_VIDEO_STM32_MAX_YRES *
462 			(CONFIG_VIDEO_STM32_MAX_BPP >> 3);
463 	dev_dbg(dev, "frame buffer max size %d bytes\n", uc_plat->size);
464 
465 	return 0;
466 }
467 
468 static const struct udevice_id stm32_ltdc_ids[] = {
469 	{ .compatible = "st,stm32-ltdc" },
470 	{ }
471 };
472 
473 U_BOOT_DRIVER(stm32_ltdc) = {
474 	.name			= "stm32_display",
475 	.id			= UCLASS_VIDEO,
476 	.of_match		= stm32_ltdc_ids,
477 	.probe			= stm32_ltdc_probe,
478 	.bind			= stm32_ltdc_bind,
479 	.priv_auto	= sizeof(struct stm32_ltdc_priv),
480 };
481