xref: /linux/drivers/video/fbdev/clps711x-fb.c (revision 4b132aacb0768ac1e652cf517097ea6f237214b9)
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_DEFAULT_IOMEM_OPS,
159 	.fb_setcolreg	= clps711x_fb_setcolreg,
160 	.fb_check_var	= clps711x_fb_check_var,
161 	.fb_set_par	= clps711x_fb_set_par,
162 	.fb_blank	= clps711x_fb_blank,
163 };
164 
165 static int clps711x_lcd_check_fb(struct lcd_device *lcddev, struct fb_info *fi)
166 {
167 	struct clps711x_fb_info *cfb = dev_get_drvdata(&lcddev->dev);
168 
169 	return (!fi || fi->par == cfb) ? 1 : 0;
170 }
171 
172 static int clps711x_lcd_get_power(struct lcd_device *lcddev)
173 {
174 	struct clps711x_fb_info *cfb = dev_get_drvdata(&lcddev->dev);
175 
176 	if (!IS_ERR_OR_NULL(cfb->lcd_pwr))
177 		if (!regulator_is_enabled(cfb->lcd_pwr))
178 			return FB_BLANK_NORMAL;
179 
180 	return FB_BLANK_UNBLANK;
181 }
182 
183 static int clps711x_lcd_set_power(struct lcd_device *lcddev, int blank)
184 {
185 	struct clps711x_fb_info *cfb = dev_get_drvdata(&lcddev->dev);
186 
187 	if (!IS_ERR_OR_NULL(cfb->lcd_pwr)) {
188 		if (blank == FB_BLANK_UNBLANK) {
189 			if (!regulator_is_enabled(cfb->lcd_pwr))
190 				return regulator_enable(cfb->lcd_pwr);
191 		} else {
192 			if (regulator_is_enabled(cfb->lcd_pwr))
193 				return regulator_disable(cfb->lcd_pwr);
194 		}
195 	}
196 
197 	return 0;
198 }
199 
200 static const struct lcd_ops clps711x_lcd_ops = {
201 	.check_fb	= clps711x_lcd_check_fb,
202 	.get_power	= clps711x_lcd_get_power,
203 	.set_power	= clps711x_lcd_set_power,
204 };
205 
206 static int clps711x_fb_probe(struct platform_device *pdev)
207 {
208 	struct device *dev = &pdev->dev;
209 	struct device_node *disp, *np = dev->of_node;
210 	struct clps711x_fb_info *cfb;
211 	struct lcd_device *lcd;
212 	struct fb_info *info;
213 	struct resource *res;
214 	int ret = -ENOENT;
215 	u32 val;
216 
217 	if (fb_get_options(CLPS711X_FB_NAME, NULL))
218 		return -ENODEV;
219 
220 	info = framebuffer_alloc(sizeof(*cfb), dev);
221 	if (!info)
222 		return -ENOMEM;
223 
224 	cfb = info->par;
225 	platform_set_drvdata(pdev, info);
226 
227 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
228 	if (!res)
229 		goto out_fb_release;
230 	cfb->base = devm_ioremap(dev, res->start, resource_size(res));
231 	if (!cfb->base) {
232 		ret = -ENOMEM;
233 		goto out_fb_release;
234 	}
235 
236 	info->fix.mmio_start = res->start;
237 	info->fix.mmio_len = resource_size(res);
238 
239 	info->screen_base = devm_platform_get_and_ioremap_resource(pdev, 1, &res);
240 	if (IS_ERR(info->screen_base)) {
241 		ret = PTR_ERR(info->screen_base);
242 		goto out_fb_release;
243 	}
244 
245 	/* Physical address should be aligned to 256 MiB */
246 	if (res->start & 0x0fffffff) {
247 		ret = -EINVAL;
248 		goto out_fb_release;
249 	}
250 
251 	cfb->buffsize = resource_size(res);
252 	info->fix.smem_start = res->start;
253 
254 	cfb->clk = devm_clk_get(dev, NULL);
255 	if (IS_ERR(cfb->clk)) {
256 		ret = PTR_ERR(cfb->clk);
257 		goto out_fb_release;
258 	}
259 
260 	cfb->syscon = syscon_regmap_lookup_by_phandle(np, "syscon");
261 	if (IS_ERR(cfb->syscon)) {
262 		ret = PTR_ERR(cfb->syscon);
263 		goto out_fb_release;
264 	}
265 
266 	disp = of_parse_phandle(np, "display", 0);
267 	if (!disp) {
268 		dev_err(&pdev->dev, "No display defined\n");
269 		ret = -ENODATA;
270 		goto out_fb_release;
271 	}
272 
273 	ret = of_get_fb_videomode(disp, &cfb->mode, OF_USE_NATIVE_MODE);
274 	if (ret) {
275 		of_node_put(disp);
276 		goto out_fb_release;
277 	}
278 
279 	of_property_read_u32(disp, "ac-prescale", &cfb->ac_prescale);
280 	cfb->cmap_invert = of_property_read_bool(disp, "cmap-invert");
281 
282 	ret = of_property_read_u32(disp, "bits-per-pixel",
283 				   &info->var.bits_per_pixel);
284 	of_node_put(disp);
285 	if (ret)
286 		goto out_fb_release;
287 
288 	/* Force disable LCD on any mismatch */
289 	if (info->fix.smem_start != (readb(cfb->base + CLPS711X_FBADDR) << 28))
290 		regmap_update_bits(cfb->syscon, SYSCON_OFFSET,
291 				   SYSCON1_LCDEN, 0);
292 
293 	ret = regmap_read(cfb->syscon, SYSCON_OFFSET, &val);
294 	if (ret)
295 		goto out_fb_release;
296 
297 	if (!(val & SYSCON1_LCDEN)) {
298 		/* Setup start FB address */
299 		writeb(info->fix.smem_start >> 28, cfb->base + CLPS711X_FBADDR);
300 		/* Clean FB memory */
301 		memset_io(info->screen_base, 0, cfb->buffsize);
302 	}
303 
304 	cfb->lcd_pwr = devm_regulator_get(dev, "lcd");
305 	if (PTR_ERR(cfb->lcd_pwr) == -EPROBE_DEFER) {
306 		ret = -EPROBE_DEFER;
307 		goto out_fb_release;
308 	}
309 
310 	info->fbops = &clps711x_fb_ops;
311 	info->var.activate = FB_ACTIVATE_FORCE | FB_ACTIVATE_NOW;
312 	info->var.height = -1;
313 	info->var.width = -1;
314 	info->var.vmode = FB_VMODE_NONINTERLACED;
315 	info->fix.type = FB_TYPE_PACKED_PIXELS;
316 	info->fix.accel = FB_ACCEL_NONE;
317 	strscpy(info->fix.id, CLPS711X_FB_NAME, sizeof(info->fix.id));
318 	fb_videomode_to_var(&info->var, &cfb->mode);
319 
320 	ret = fb_alloc_cmap(&info->cmap, BIT(CLPS711X_FB_BPP_MAX), 0);
321 	if (ret)
322 		goto out_fb_release;
323 
324 	ret = fb_set_var(info, &info->var);
325 	if (ret)
326 		goto out_fb_dealloc_cmap;
327 
328 	ret = register_framebuffer(info);
329 	if (ret)
330 		goto out_fb_dealloc_cmap;
331 
332 	lcd = devm_lcd_device_register(dev, "clps711x-lcd", dev, cfb,
333 				       &clps711x_lcd_ops);
334 	if (!IS_ERR(lcd))
335 		return 0;
336 
337 	ret = PTR_ERR(lcd);
338 	unregister_framebuffer(info);
339 
340 out_fb_dealloc_cmap:
341 	regmap_update_bits(cfb->syscon, SYSCON_OFFSET, SYSCON1_LCDEN, 0);
342 	fb_dealloc_cmap(&info->cmap);
343 
344 out_fb_release:
345 	framebuffer_release(info);
346 
347 	return ret;
348 }
349 
350 static void clps711x_fb_remove(struct platform_device *pdev)
351 {
352 	struct fb_info *info = platform_get_drvdata(pdev);
353 	struct clps711x_fb_info *cfb = info->par;
354 
355 	regmap_update_bits(cfb->syscon, SYSCON_OFFSET, SYSCON1_LCDEN, 0);
356 
357 	unregister_framebuffer(info);
358 	fb_dealloc_cmap(&info->cmap);
359 	framebuffer_release(info);
360 }
361 
362 static const struct of_device_id clps711x_fb_dt_ids[] = {
363 	{ .compatible = "cirrus,ep7209-fb", },
364 	{ }
365 };
366 MODULE_DEVICE_TABLE(of, clps711x_fb_dt_ids);
367 
368 static struct platform_driver clps711x_fb_driver = {
369 	.driver	= {
370 		.name		= CLPS711X_FB_NAME,
371 		.of_match_table	= clps711x_fb_dt_ids,
372 	},
373 	.probe	= clps711x_fb_probe,
374 	.remove_new = clps711x_fb_remove,
375 };
376 module_platform_driver(clps711x_fb_driver);
377 
378 MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
379 MODULE_DESCRIPTION("Cirrus Logic CLPS711X FB driver");
380 MODULE_LICENSE("GPL");
381