clps711x-fb.c

  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_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
165static 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
176static 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
193static const struct lcd_ops clps711x_lcd_ops = {
194	.get_power	= clps711x_lcd_get_power,
195	.set_power	= clps711x_lcd_set_power,
196};
197
198static 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
337out_fb_dealloc_cmap:
338	regmap_update_bits(cfb->syscon, SYSCON_OFFSET, SYSCON1_LCDEN, 0);
339	fb_dealloc_cmap(&info->cmap);
340
341out_fb_release:
342	framebuffer_release(info);
343
344	return ret;
345}
346
347static 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
359static const struct of_device_id clps711x_fb_dt_ids[] = {
360	{ .compatible = "cirrus,ep7209-fb", },
361	{ }
362};
363MODULE_DEVICE_TABLE(of, clps711x_fb_dt_ids);
364
365static 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};
373module_platform_driver(clps711x_fb_driver);
374
375MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
376MODULE_DESCRIPTION("Cirrus Logic CLPS711X FB driver");
377MODULE_LICENSE("GPL");