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
33struct 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
44static 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
67static 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
101static 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
150static int clps711x_fb_blank(int blank, struct fb_info *info)
151{
152	/* Return happy */
153	return 0;
154}
155
156static 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
167static 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
174static 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
185static 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
202static 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
208static 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	info->screen_base = devm_platform_get_and_ioremap_resource(pdev, 1, &res);
242	if (IS_ERR(info->screen_base)) {
243		ret = PTR_ERR(info->screen_base);
244		goto out_fb_release;
245	}
246
247	/* Physical address should be aligned to 256 MiB */
248	if (res->start & 0x0fffffff) {
249		ret = -EINVAL;
250		goto out_fb_release;
251	}
252
253	cfb->buffsize = resource_size(res);
254	info->fix.smem_start = res->start;
255
256	cfb->clk = devm_clk_get(dev, NULL);
257	if (IS_ERR(cfb->clk)) {
258		ret = PTR_ERR(cfb->clk);
259		goto out_fb_release;
260	}
261
262	cfb->syscon = syscon_regmap_lookup_by_phandle(np, "syscon");
263	if (IS_ERR(cfb->syscon)) {
264		ret = PTR_ERR(cfb->syscon);
265		goto out_fb_release;
266	}
267
268	disp = of_parse_phandle(np, "display", 0);
269	if (!disp) {
270		dev_err(&pdev->dev, "No display defined\n");
271		ret = -ENODATA;
272		goto out_fb_release;
273	}
274
275	ret = of_get_fb_videomode(disp, &cfb->mode, OF_USE_NATIVE_MODE);
276	if (ret) {
277		of_node_put(disp);
278		goto out_fb_release;
279	}
280
281	of_property_read_u32(disp, "ac-prescale", &cfb->ac_prescale);
282	cfb->cmap_invert = of_property_read_bool(disp, "cmap-invert");
283
284	ret = of_property_read_u32(disp, "bits-per-pixel",
285				   &info->var.bits_per_pixel);
286	of_node_put(disp);
287	if (ret)
288		goto out_fb_release;
289
290	/* Force disable LCD on any mismatch */
291	if (info->fix.smem_start != (readb(cfb->base + CLPS711X_FBADDR) << 28))
292		regmap_update_bits(cfb->syscon, SYSCON_OFFSET,
293				   SYSCON1_LCDEN, 0);
294
295	ret = regmap_read(cfb->syscon, SYSCON_OFFSET, &val);
296	if (ret)
297		goto out_fb_release;
298
299	if (!(val & SYSCON1_LCDEN)) {
300		/* Setup start FB address */
301		writeb(info->fix.smem_start >> 28, cfb->base + CLPS711X_FBADDR);
302		/* Clean FB memory */
303		memset_io(info->screen_base, 0, cfb->buffsize);
304	}
305
306	cfb->lcd_pwr = devm_regulator_get(dev, "lcd");
307	if (PTR_ERR(cfb->lcd_pwr) == -EPROBE_DEFER) {
308		ret = -EPROBE_DEFER;
309		goto out_fb_release;
310	}
311
312	info->fbops = &clps711x_fb_ops;
313	info->var.activate = FB_ACTIVATE_FORCE | FB_ACTIVATE_NOW;
314	info->var.height = -1;
315	info->var.width = -1;
316	info->var.vmode = FB_VMODE_NONINTERLACED;
317	info->fix.type = FB_TYPE_PACKED_PIXELS;
318	info->fix.accel = FB_ACCEL_NONE;
319	strscpy(info->fix.id, CLPS711X_FB_NAME, sizeof(info->fix.id));
320	fb_videomode_to_var(&info->var, &cfb->mode);
321
322	ret = fb_alloc_cmap(&info->cmap, BIT(CLPS711X_FB_BPP_MAX), 0);
323	if (ret)
324		goto out_fb_release;
325
326	ret = fb_set_var(info, &info->var);
327	if (ret)
328		goto out_fb_dealloc_cmap;
329
330	ret = register_framebuffer(info);
331	if (ret)
332		goto out_fb_dealloc_cmap;
333
334	lcd = devm_lcd_device_register(dev, "clps711x-lcd", dev, cfb,
335				       &clps711x_lcd_ops);
336	if (!IS_ERR(lcd))
337		return 0;
338
339	ret = PTR_ERR(lcd);
340	unregister_framebuffer(info);
341
342out_fb_dealloc_cmap:
343	regmap_update_bits(cfb->syscon, SYSCON_OFFSET, SYSCON1_LCDEN, 0);
344	fb_dealloc_cmap(&info->cmap);
345
346out_fb_release:
347	framebuffer_release(info);
348
349	return ret;
350}
351
352static void clps711x_fb_remove(struct platform_device *pdev)
353{
354	struct fb_info *info = platform_get_drvdata(pdev);
355	struct clps711x_fb_info *cfb = info->par;
356
357	regmap_update_bits(cfb->syscon, SYSCON_OFFSET, SYSCON1_LCDEN, 0);
358
359	unregister_framebuffer(info);
360	fb_dealloc_cmap(&info->cmap);
361	framebuffer_release(info);
362}
363
364static const struct of_device_id clps711x_fb_dt_ids[] = {
365	{ .compatible = "cirrus,ep7209-fb", },
366	{ }
367};
368MODULE_DEVICE_TABLE(of, clps711x_fb_dt_ids);
369
370static struct platform_driver clps711x_fb_driver = {
371	.driver	= {
372		.name		= CLPS711X_FB_NAME,
373		.of_match_table	= clps711x_fb_dt_ids,
374	},
375	.probe	= clps711x_fb_probe,
376	.remove_new = clps711x_fb_remove,
377};
378module_platform_driver(clps711x_fb_driver);
379
380MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
381MODULE_DESCRIPTION("Cirrus Logic CLPS711X FB driver");
382MODULE_LICENSE("GPL");
383