1/*
2 * Cirrus Logic CLPS711X FB driver
3 *
4 * Copyright (C) 2014 Alexander Shiyan <shc_work@mail.ru>
5 * Based on driver by Russell King <rmk@arm.linux.org.uk>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 */
12
13#include <linux/clk.h>
14#include <linux/fb.h>
15#include <linux/io.h>
16#include <linux/lcd.h>
17#include <linux/module.h>
18#include <linux/of.h>
19#include <linux/platform_device.h>
20#include <linux/regmap.h>
21#include <linux/mfd/syscon.h>
22#include <linux/mfd/syscon/clps711x.h>
23#include <linux/regulator/consumer.h>
24#include <video/of_display_timing.h>
25
26#define CLPS711X_FB_NAME	"clps711x-fb"
27#define CLPS711X_FB_BPP_MAX	(4)
28
29/* Registers relative to LCDCON */
30#define CLPS711X_LCDCON		(0x0000)
31# define LCDCON_GSEN		BIT(30)
32# define LCDCON_GSMD		BIT(31)
33#define CLPS711X_PALLSW		(0x0280)
34#define CLPS711X_PALMSW		(0x02c0)
35#define CLPS711X_FBADDR		(0x0d40)
36
37struct clps711x_fb_info {
38	struct clk		*clk;
39	void __iomem		*base;
40	struct regmap		*syscon;
41	resource_size_t		buffsize;
42	struct fb_videomode	mode;
43	struct regulator	*lcd_pwr;
44	u32			ac_prescale;
45	bool			cmap_invert;
46};
47
48static int clps711x_fb_setcolreg(u_int regno, u_int red, u_int green,
49				 u_int blue, u_int transp, struct fb_info *info)
50{
51	struct clps711x_fb_info *cfb = info->par;
52	u32 level, mask, shift;
53
54	if (regno >= BIT(info->var.bits_per_pixel))
55		return -EINVAL;
56
57	shift = 4 * (regno & 7);
58	mask  = 0xf << shift;
59	/* gray = 0.30*R + 0.58*G + 0.11*B */
60	level = (((red * 77 + green * 151 + blue * 28) >> 20) << shift) & mask;
61	if (cfb->cmap_invert)
62		level = 0xf - level;
63
64	regno = (regno < 8) ? CLPS711X_PALLSW : CLPS711X_PALMSW;
65
66	writel((readl(cfb->base + regno) & ~mask) | level, cfb->base + regno);
67
68	return 0;
69}
70
71static int clps711x_fb_check_var(struct fb_var_screeninfo *var,
72				 struct fb_info *info)
73{
74	u32 val;
75
76	if (var->bits_per_pixel < 1 ||
77	    var->bits_per_pixel > CLPS711X_FB_BPP_MAX)
78		return -EINVAL;
79
80	if (!var->pixclock)
81		return -EINVAL;
82
83	val = DIV_ROUND_UP(var->xres, 16) - 1;
84	if (val < 0x01 || val > 0x3f)
85		return -EINVAL;
86
87	val = DIV_ROUND_UP(var->yres * var->xres * var->bits_per_pixel, 128);
88	val--;
89	if (val < 0x001 || val > 0x1fff)
90		return -EINVAL;
91
92	var->transp.msb_right	= 0;
93	var->transp.offset	= 0;
94	var->transp.length	= 0;
95	var->red.msb_right	= 0;
96	var->red.offset		= 0;
97	var->red.length		= var->bits_per_pixel;
98	var->green		= var->red;
99	var->blue		= var->red;
100	var->grayscale		= var->bits_per_pixel > 1;
101
102	return 0;
103}
104
105static int clps711x_fb_set_par(struct fb_info *info)
106{
107	struct clps711x_fb_info *cfb = info->par;
108	resource_size_t size;
109	u32 lcdcon, pps;
110
111	size = (info->var.xres * info->var.yres * info->var.bits_per_pixel) / 8;
112	if (size > cfb->buffsize)
113		return -EINVAL;
114
115	switch (info->var.bits_per_pixel) {
116	case 1:
117		info->fix.visual = FB_VISUAL_MONO01;
118		break;
119	case 2:
120	case 4:
121		info->fix.visual = FB_VISUAL_PSEUDOCOLOR;
122		break;
123	default:
124		return -EINVAL;
125	}
126
127	info->fix.line_length = info->var.xres * info->var.bits_per_pixel / 8;
128	info->fix.smem_len = size;
129
130	lcdcon = (info->var.xres * info->var.yres *
131		  info->var.bits_per_pixel) / 128 - 1;
132	lcdcon |= ((info->var.xres / 16) - 1) << 13;
133	lcdcon |= (cfb->ac_prescale & 0x1f) << 25;
134
135	pps = clk_get_rate(cfb->clk) / (PICOS2KHZ(info->var.pixclock) * 1000);
136	if (pps)
137		pps--;
138	lcdcon |= (pps & 0x3f) << 19;
139
140	if (info->var.bits_per_pixel == 4)
141		lcdcon |= LCDCON_GSMD;
142	if (info->var.bits_per_pixel >= 2)
143		lcdcon |= LCDCON_GSEN;
144
145	/* LCDCON must only be changed while the LCD is disabled */
146	regmap_update_bits(cfb->syscon, SYSCON_OFFSET, SYSCON1_LCDEN, 0);
147	writel(lcdcon, cfb->base + CLPS711X_LCDCON);
148	regmap_update_bits(cfb->syscon, SYSCON_OFFSET,
149			   SYSCON1_LCDEN, SYSCON1_LCDEN);
150
151	return 0;
152}
153
154static int clps711x_fb_blank(int blank, struct fb_info *info)
155{
156	/* Return happy */
157	return 0;
158}
159
160static struct fb_ops clps711x_fb_ops = {
161	.owner		= THIS_MODULE,
162	.fb_setcolreg	= clps711x_fb_setcolreg,
163	.fb_check_var	= clps711x_fb_check_var,
164	.fb_set_par	= clps711x_fb_set_par,
165	.fb_blank	= clps711x_fb_blank,
166	.fb_fillrect	= sys_fillrect,
167	.fb_copyarea	= sys_copyarea,
168	.fb_imageblit	= sys_imageblit,
169};
170
171static int clps711x_lcd_check_fb(struct lcd_device *lcddev, struct fb_info *fi)
172{
173	struct clps711x_fb_info *cfb = dev_get_drvdata(&lcddev->dev);
174
175	return (!fi || fi->par == cfb) ? 1 : 0;
176}
177
178static int clps711x_lcd_get_power(struct lcd_device *lcddev)
179{
180	struct clps711x_fb_info *cfb = dev_get_drvdata(&lcddev->dev);
181
182	if (!IS_ERR_OR_NULL(cfb->lcd_pwr))
183		if (!regulator_is_enabled(cfb->lcd_pwr))
184			return FB_BLANK_NORMAL;
185
186	return FB_BLANK_UNBLANK;
187}
188
189static int clps711x_lcd_set_power(struct lcd_device *lcddev, int blank)
190{
191	struct clps711x_fb_info *cfb = dev_get_drvdata(&lcddev->dev);
192
193	if (!IS_ERR_OR_NULL(cfb->lcd_pwr)) {
194		if (blank == FB_BLANK_UNBLANK) {
195			if (!regulator_is_enabled(cfb->lcd_pwr))
196				return regulator_enable(cfb->lcd_pwr);
197		} else {
198			if (regulator_is_enabled(cfb->lcd_pwr))
199				return regulator_disable(cfb->lcd_pwr);
200		}
201	}
202
203	return 0;
204}
205
206static struct lcd_ops clps711x_lcd_ops = {
207	.check_fb	= clps711x_lcd_check_fb,
208	.get_power	= clps711x_lcd_get_power,
209	.set_power	= clps711x_lcd_set_power,
210};
211
212static int clps711x_fb_probe(struct platform_device *pdev)
213{
214	struct device *dev = &pdev->dev;
215	struct device_node *disp, *np = dev->of_node;
216	struct clps711x_fb_info *cfb;
217	struct lcd_device *lcd;
218	struct fb_info *info;
219	struct resource *res;
220	int ret = -ENOENT;
221	u32 val;
222
223	if (fb_get_options(CLPS711X_FB_NAME, NULL))
224		return -ENODEV;
225
226	info = framebuffer_alloc(sizeof(*cfb), dev);
227	if (!info)
228		return -ENOMEM;
229
230	cfb = info->par;
231	platform_set_drvdata(pdev, info);
232
233	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
234	if (!res)
235		goto out_fb_release;
236	cfb->base = devm_ioremap(dev, res->start, resource_size(res));
237	if (!cfb->base) {
238		ret = -ENOMEM;
239		goto out_fb_release;
240	}
241
242	info->fix.mmio_start = res->start;
243	info->fix.mmio_len = resource_size(res);
244
245	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
246	info->screen_base = devm_ioremap_resource(dev, res);
247	if (IS_ERR(info->screen_base)) {
248		ret = PTR_ERR(info->screen_base);
249		goto out_fb_release;
250	}
251
252	/* Physical address should be aligned to 256 MiB */
253	if (res->start & 0x0fffffff) {
254		ret = -EINVAL;
255		goto out_fb_release;
256	}
257
258	info->apertures = alloc_apertures(1);
259	if (!info->apertures) {
260		ret = -ENOMEM;
261		goto out_fb_release;
262	}
263
264	cfb->buffsize = resource_size(res);
265	info->fix.smem_start = res->start;
266	info->apertures->ranges[0].base = info->fix.smem_start;
267	info->apertures->ranges[0].size = cfb->buffsize;
268
269	cfb->clk = devm_clk_get(dev, NULL);
270	if (IS_ERR(cfb->clk)) {
271		ret = PTR_ERR(cfb->clk);
272		goto out_fb_release;
273	}
274
275	cfb->syscon =
276		syscon_regmap_lookup_by_compatible("cirrus,clps711x-syscon1");
277	if (IS_ERR(cfb->syscon)) {
278		ret = PTR_ERR(cfb->syscon);
279		goto out_fb_release;
280	}
281
282	disp = of_parse_phandle(np, "display", 0);
283	if (!disp) {
284		dev_err(&pdev->dev, "No display defined\n");
285		ret = -ENODATA;
286		goto out_fb_release;
287	}
288
289	ret = of_get_fb_videomode(disp, &cfb->mode, OF_USE_NATIVE_MODE);
290	if (ret)
291		goto out_fb_release;
292
293	of_property_read_u32(disp, "ac-prescale", &cfb->ac_prescale);
294	cfb->cmap_invert = of_property_read_bool(disp, "cmap-invert");
295
296	ret = of_property_read_u32(disp, "bits-per-pixel",
297				   &info->var.bits_per_pixel);
298	if (ret)
299		goto out_fb_release;
300
301	/* Force disable LCD on any mismatch */
302	if (info->fix.smem_start != (readb(cfb->base + CLPS711X_FBADDR) << 28))
303		regmap_update_bits(cfb->syscon, SYSCON_OFFSET,
304				   SYSCON1_LCDEN, 0);
305
306	ret = regmap_read(cfb->syscon, SYSCON_OFFSET, &val);
307	if (ret)
308		goto out_fb_release;
309
310	if (!(val & SYSCON1_LCDEN)) {
311		/* Setup start FB address */
312		writeb(info->fix.smem_start >> 28, cfb->base + CLPS711X_FBADDR);
313		/* Clean FB memory */
314		memset_io(info->screen_base, 0, cfb->buffsize);
315	}
316
317	cfb->lcd_pwr = devm_regulator_get(dev, "lcd");
318	if (PTR_ERR(cfb->lcd_pwr) == -EPROBE_DEFER) {
319		ret = -EPROBE_DEFER;
320		goto out_fb_release;
321	}
322
323	info->fbops = &clps711x_fb_ops;
324	info->flags = FBINFO_DEFAULT;
325	info->var.activate = FB_ACTIVATE_FORCE | FB_ACTIVATE_NOW;
326	info->var.height = -1;
327	info->var.width = -1;
328	info->var.vmode = FB_VMODE_NONINTERLACED;
329	info->fix.type = FB_TYPE_PACKED_PIXELS;
330	info->fix.accel = FB_ACCEL_NONE;
331	strlcpy(info->fix.id, CLPS711X_FB_NAME, sizeof(info->fix.id));
332	fb_videomode_to_var(&info->var, &cfb->mode);
333
334	ret = fb_alloc_cmap(&info->cmap, BIT(CLPS711X_FB_BPP_MAX), 0);
335	if (ret)
336		goto out_fb_release;
337
338	ret = fb_set_var(info, &info->var);
339	if (ret)
340		goto out_fb_dealloc_cmap;
341
342	ret = register_framebuffer(info);
343	if (ret)
344		goto out_fb_dealloc_cmap;
345
346	lcd = devm_lcd_device_register(dev, "clps711x-lcd", dev, cfb,
347				       &clps711x_lcd_ops);
348	if (!IS_ERR(lcd))
349		return 0;
350
351	ret = PTR_ERR(lcd);
352	unregister_framebuffer(info);
353
354out_fb_dealloc_cmap:
355	regmap_update_bits(cfb->syscon, SYSCON_OFFSET, SYSCON1_LCDEN, 0);
356	fb_dealloc_cmap(&info->cmap);
357
358out_fb_release:
359	framebuffer_release(info);
360
361	return ret;
362}
363
364static int clps711x_fb_remove(struct platform_device *pdev)
365{
366	struct fb_info *info = platform_get_drvdata(pdev);
367	struct clps711x_fb_info *cfb = info->par;
368
369	regmap_update_bits(cfb->syscon, SYSCON_OFFSET, SYSCON1_LCDEN, 0);
370
371	unregister_framebuffer(info);
372	fb_dealloc_cmap(&info->cmap);
373	framebuffer_release(info);
374
375	return 0;
376}
377
378static const struct of_device_id clps711x_fb_dt_ids[] = {
379	{ .compatible = "cirrus,clps711x-fb", },
380	{ }
381};
382MODULE_DEVICE_TABLE(of, clps711x_fb_dt_ids);
383
384static struct platform_driver clps711x_fb_driver = {
385	.driver	= {
386		.name		= CLPS711X_FB_NAME,
387		.of_match_table	= clps711x_fb_dt_ids,
388	},
389	.probe	= clps711x_fb_probe,
390	.remove	= clps711x_fb_remove,
391};
392module_platform_driver(clps711x_fb_driver);
393
394MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
395MODULE_DESCRIPTION("Cirrus Logic CLPS711X FB driver");
396MODULE_LICENSE("GPL");
397