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