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