1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Cirrus Logic CLPS711X FB driver
4  *
5  * Copyright (C) 2014 Alexander Shiyan <shc_work@mail.ru>
6  * Based on driver by Russell King <rmk@arm.linux.org.uk>
7  */
8 
9 #include <linux/clk.h>
10 #include <linux/fb.h>
11 #include <linux/io.h>
12 #include <linux/lcd.h>
13 #include <linux/module.h>
14 #include <linux/of.h>
15 #include <linux/platform_device.h>
16 #include <linux/regmap.h>
17 #include <linux/mfd/syscon.h>
18 #include <linux/mfd/syscon/clps711x.h>
19 #include <linux/regulator/consumer.h>
20 #include <video/of_display_timing.h>
21 
22 #define CLPS711X_FB_NAME	"clps711x-fb"
23 #define CLPS711X_FB_BPP_MAX	(4)
24 
25 /* Registers relative to LCDCON */
26 #define CLPS711X_LCDCON		(0x0000)
27 # define LCDCON_GSEN		BIT(30)
28 # define LCDCON_GSMD		BIT(31)
29 #define CLPS711X_PALLSW		(0x0280)
30 #define CLPS711X_PALMSW		(0x02c0)
31 #define CLPS711X_FBADDR		(0x0d40)
32 
33 struct clps711x_fb_info {
34 	struct clk		*clk;
35 	void __iomem		*base;
36 	struct regmap		*syscon;
37 	resource_size_t		buffsize;
38 	struct fb_videomode	mode;
39 	struct regulator	*lcd_pwr;
40 	u32			ac_prescale;
41 	bool			cmap_invert;
42 };
43 
44 static int clps711x_fb_setcolreg(u_int regno, u_int red, u_int green,
45 				 u_int blue, u_int transp, struct fb_info *info)
46 {
47 	struct clps711x_fb_info *cfb = info->par;
48 	u32 level, mask, shift;
49 
50 	if (regno >= BIT(info->var.bits_per_pixel))
51 		return -EINVAL;
52 
53 	shift = 4 * (regno & 7);
54 	mask  = 0xf << shift;
55 	/* gray = 0.30*R + 0.58*G + 0.11*B */
56 	level = (((red * 77 + green * 151 + blue * 28) >> 20) << shift) & mask;
57 	if (cfb->cmap_invert)
58 		level = 0xf - level;
59 
60 	regno = (regno < 8) ? CLPS711X_PALLSW : CLPS711X_PALMSW;
61 
62 	writel((readl(cfb->base + regno) & ~mask) | level, cfb->base + regno);
63 
64 	return 0;
65 }
66 
67 static int clps711x_fb_check_var(struct fb_var_screeninfo *var,
68 				 struct fb_info *info)
69 {
70 	u32 val;
71 
72 	if (var->bits_per_pixel < 1 ||
73 	    var->bits_per_pixel > CLPS711X_FB_BPP_MAX)
74 		return -EINVAL;
75 
76 	if (!var->pixclock)
77 		return -EINVAL;
78 
79 	val = DIV_ROUND_UP(var->xres, 16) - 1;
80 	if (val < 0x01 || val > 0x3f)
81 		return -EINVAL;
82 
83 	val = DIV_ROUND_UP(var->yres * var->xres * var->bits_per_pixel, 128);
84 	val--;
85 	if (val < 0x001 || val > 0x1fff)
86 		return -EINVAL;
87 
88 	var->transp.msb_right	= 0;
89 	var->transp.offset	= 0;
90 	var->transp.length	= 0;
91 	var->red.msb_right	= 0;
92 	var->red.offset		= 0;
93 	var->red.length		= var->bits_per_pixel;
94 	var->green		= var->red;
95 	var->blue		= var->red;
96 	var->grayscale		= var->bits_per_pixel > 1;
97 
98 	return 0;
99 }
100 
101 static int clps711x_fb_set_par(struct fb_info *info)
102 {
103 	struct clps711x_fb_info *cfb = info->par;
104 	resource_size_t size;
105 	u32 lcdcon, pps;
106 
107 	size = (info->var.xres * info->var.yres * info->var.bits_per_pixel) / 8;
108 	if (size > cfb->buffsize)
109 		return -EINVAL;
110 
111 	switch (info->var.bits_per_pixel) {
112 	case 1:
113 		info->fix.visual = FB_VISUAL_MONO01;
114 		break;
115 	case 2:
116 	case 4:
117 		info->fix.visual = FB_VISUAL_PSEUDOCOLOR;
118 		break;
119 	default:
120 		return -EINVAL;
121 	}
122 
123 	info->fix.line_length = info->var.xres * info->var.bits_per_pixel / 8;
124 	info->fix.smem_len = size;
125 
126 	lcdcon = (info->var.xres * info->var.yres *
127 		  info->var.bits_per_pixel) / 128 - 1;
128 	lcdcon |= ((info->var.xres / 16) - 1) << 13;
129 	lcdcon |= (cfb->ac_prescale & 0x1f) << 25;
130 
131 	pps = clk_get_rate(cfb->clk) / (PICOS2KHZ(info->var.pixclock) * 1000);
132 	if (pps)
133 		pps--;
134 	lcdcon |= (pps & 0x3f) << 19;
135 
136 	if (info->var.bits_per_pixel == 4)
137 		lcdcon |= LCDCON_GSMD;
138 	if (info->var.bits_per_pixel >= 2)
139 		lcdcon |= LCDCON_GSEN;
140 
141 	/* LCDCON must only be changed while the LCD is disabled */
142 	regmap_update_bits(cfb->syscon, SYSCON_OFFSET, SYSCON1_LCDEN, 0);
143 	writel(lcdcon, cfb->base + CLPS711X_LCDCON);
144 	regmap_update_bits(cfb->syscon, SYSCON_OFFSET,
145 			   SYSCON1_LCDEN, SYSCON1_LCDEN);
146 
147 	return 0;
148 }
149 
150 static int clps711x_fb_blank(int blank, struct fb_info *info)
151 {
152 	/* Return happy */
153 	return 0;
154 }
155 
156 static const struct fb_ops clps711x_fb_ops = {
157 	.owner		= THIS_MODULE,
158 	.fb_setcolreg	= clps711x_fb_setcolreg,
159 	.fb_check_var	= clps711x_fb_check_var,
160 	.fb_set_par	= clps711x_fb_set_par,
161 	.fb_blank	= clps711x_fb_blank,
162 	.fb_fillrect	= sys_fillrect,
163 	.fb_copyarea	= sys_copyarea,
164 	.fb_imageblit	= sys_imageblit,
165 };
166 
167 static int clps711x_lcd_check_fb(struct lcd_device *lcddev, struct fb_info *fi)
168 {
169 	struct clps711x_fb_info *cfb = dev_get_drvdata(&lcddev->dev);
170 
171 	return (!fi || fi->par == cfb) ? 1 : 0;
172 }
173 
174 static int clps711x_lcd_get_power(struct lcd_device *lcddev)
175 {
176 	struct clps711x_fb_info *cfb = dev_get_drvdata(&lcddev->dev);
177 
178 	if (!IS_ERR_OR_NULL(cfb->lcd_pwr))
179 		if (!regulator_is_enabled(cfb->lcd_pwr))
180 			return FB_BLANK_NORMAL;
181 
182 	return FB_BLANK_UNBLANK;
183 }
184 
185 static int clps711x_lcd_set_power(struct lcd_device *lcddev, int blank)
186 {
187 	struct clps711x_fb_info *cfb = dev_get_drvdata(&lcddev->dev);
188 
189 	if (!IS_ERR_OR_NULL(cfb->lcd_pwr)) {
190 		if (blank == FB_BLANK_UNBLANK) {
191 			if (!regulator_is_enabled(cfb->lcd_pwr))
192 				return regulator_enable(cfb->lcd_pwr);
193 		} else {
194 			if (regulator_is_enabled(cfb->lcd_pwr))
195 				return regulator_disable(cfb->lcd_pwr);
196 		}
197 	}
198 
199 	return 0;
200 }
201 
202 static struct lcd_ops clps711x_lcd_ops = {
203 	.check_fb	= clps711x_lcd_check_fb,
204 	.get_power	= clps711x_lcd_get_power,
205 	.set_power	= clps711x_lcd_set_power,
206 };
207 
208 static int clps711x_fb_probe(struct platform_device *pdev)
209 {
210 	struct device *dev = &pdev->dev;
211 	struct device_node *disp, *np = dev->of_node;
212 	struct clps711x_fb_info *cfb;
213 	struct lcd_device *lcd;
214 	struct fb_info *info;
215 	struct resource *res;
216 	int ret = -ENOENT;
217 	u32 val;
218 
219 	if (fb_get_options(CLPS711X_FB_NAME, NULL))
220 		return -ENODEV;
221 
222 	info = framebuffer_alloc(sizeof(*cfb), dev);
223 	if (!info)
224 		return -ENOMEM;
225 
226 	cfb = info->par;
227 	platform_set_drvdata(pdev, info);
228 
229 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
230 	if (!res)
231 		goto out_fb_release;
232 	cfb->base = devm_ioremap(dev, res->start, resource_size(res));
233 	if (!cfb->base) {
234 		ret = -ENOMEM;
235 		goto out_fb_release;
236 	}
237 
238 	info->fix.mmio_start = res->start;
239 	info->fix.mmio_len = resource_size(res);
240 
241 	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
242 	info->screen_base = devm_ioremap_resource(dev, res);
243 	if (IS_ERR(info->screen_base)) {
244 		ret = PTR_ERR(info->screen_base);
245 		goto out_fb_release;
246 	}
247 
248 	/* Physical address should be aligned to 256 MiB */
249 	if (res->start & 0x0fffffff) {
250 		ret = -EINVAL;
251 		goto out_fb_release;
252 	}
253 
254 	cfb->buffsize = resource_size(res);
255 	info->fix.smem_start = res->start;
256 
257 	cfb->clk = devm_clk_get(dev, NULL);
258 	if (IS_ERR(cfb->clk)) {
259 		ret = PTR_ERR(cfb->clk);
260 		goto out_fb_release;
261 	}
262 
263 	cfb->syscon = syscon_regmap_lookup_by_phandle(np, "syscon");
264 	if (IS_ERR(cfb->syscon)) {
265 		ret = PTR_ERR(cfb->syscon);
266 		goto out_fb_release;
267 	}
268 
269 	disp = of_parse_phandle(np, "display", 0);
270 	if (!disp) {
271 		dev_err(&pdev->dev, "No display defined\n");
272 		ret = -ENODATA;
273 		goto out_fb_release;
274 	}
275 
276 	ret = of_get_fb_videomode(disp, &cfb->mode, OF_USE_NATIVE_MODE);
277 	if (ret) {
278 		of_node_put(disp);
279 		goto out_fb_release;
280 	}
281 
282 	of_property_read_u32(disp, "ac-prescale", &cfb->ac_prescale);
283 	cfb->cmap_invert = of_property_read_bool(disp, "cmap-invert");
284 
285 	ret = of_property_read_u32(disp, "bits-per-pixel",
286 				   &info->var.bits_per_pixel);
287 	of_node_put(disp);
288 	if (ret)
289 		goto out_fb_release;
290 
291 	/* Force disable LCD on any mismatch */
292 	if (info->fix.smem_start != (readb(cfb->base + CLPS711X_FBADDR) << 28))
293 		regmap_update_bits(cfb->syscon, SYSCON_OFFSET,
294 				   SYSCON1_LCDEN, 0);
295 
296 	ret = regmap_read(cfb->syscon, SYSCON_OFFSET, &val);
297 	if (ret)
298 		goto out_fb_release;
299 
300 	if (!(val & SYSCON1_LCDEN)) {
301 		/* Setup start FB address */
302 		writeb(info->fix.smem_start >> 28, cfb->base + CLPS711X_FBADDR);
303 		/* Clean FB memory */
304 		memset_io(info->screen_base, 0, cfb->buffsize);
305 	}
306 
307 	cfb->lcd_pwr = devm_regulator_get(dev, "lcd");
308 	if (PTR_ERR(cfb->lcd_pwr) == -EPROBE_DEFER) {
309 		ret = -EPROBE_DEFER;
310 		goto out_fb_release;
311 	}
312 
313 	info->fbops = &clps711x_fb_ops;
314 	info->flags = FBINFO_DEFAULT;
315 	info->var.activate = FB_ACTIVATE_FORCE | FB_ACTIVATE_NOW;
316 	info->var.height = -1;
317 	info->var.width = -1;
318 	info->var.vmode = FB_VMODE_NONINTERLACED;
319 	info->fix.type = FB_TYPE_PACKED_PIXELS;
320 	info->fix.accel = FB_ACCEL_NONE;
321 	strscpy(info->fix.id, CLPS711X_FB_NAME, sizeof(info->fix.id));
322 	fb_videomode_to_var(&info->var, &cfb->mode);
323 
324 	ret = fb_alloc_cmap(&info->cmap, BIT(CLPS711X_FB_BPP_MAX), 0);
325 	if (ret)
326 		goto out_fb_release;
327 
328 	ret = fb_set_var(info, &info->var);
329 	if (ret)
330 		goto out_fb_dealloc_cmap;
331 
332 	ret = register_framebuffer(info);
333 	if (ret)
334 		goto out_fb_dealloc_cmap;
335 
336 	lcd = devm_lcd_device_register(dev, "clps711x-lcd", dev, cfb,
337 				       &clps711x_lcd_ops);
338 	if (!IS_ERR(lcd))
339 		return 0;
340 
341 	ret = PTR_ERR(lcd);
342 	unregister_framebuffer(info);
343 
344 out_fb_dealloc_cmap:
345 	regmap_update_bits(cfb->syscon, SYSCON_OFFSET, SYSCON1_LCDEN, 0);
346 	fb_dealloc_cmap(&info->cmap);
347 
348 out_fb_release:
349 	framebuffer_release(info);
350 
351 	return ret;
352 }
353 
354 static int clps711x_fb_remove(struct platform_device *pdev)
355 {
356 	struct fb_info *info = platform_get_drvdata(pdev);
357 	struct clps711x_fb_info *cfb = info->par;
358 
359 	regmap_update_bits(cfb->syscon, SYSCON_OFFSET, SYSCON1_LCDEN, 0);
360 
361 	unregister_framebuffer(info);
362 	fb_dealloc_cmap(&info->cmap);
363 	framebuffer_release(info);
364 
365 	return 0;
366 }
367 
368 static const struct of_device_id clps711x_fb_dt_ids[] = {
369 	{ .compatible = "cirrus,ep7209-fb", },
370 	{ }
371 };
372 MODULE_DEVICE_TABLE(of, clps711x_fb_dt_ids);
373 
374 static struct platform_driver clps711x_fb_driver = {
375 	.driver	= {
376 		.name		= CLPS711X_FB_NAME,
377 		.of_match_table	= clps711x_fb_dt_ids,
378 	},
379 	.probe	= clps711x_fb_probe,
380 	.remove	= clps711x_fb_remove,
381 };
382 module_platform_driver(clps711x_fb_driver);
383 
384 MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
385 MODULE_DESCRIPTION("Cirrus Logic CLPS711X FB driver");
386 MODULE_LICENSE("GPL");
387