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