1/*
2 *  linux/drivers/video/clps711xfb.c
3 *
4 *  Copyright (C) 2000-2001 Deep Blue Solutions Ltd.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
19 *
20 *  Framebuffer driver for the CLPS7111 and EP7212 processors.
21 */
22#include <linux/mm.h>
23#include <linux/module.h>
24#include <linux/kernel.h>
25#include <linux/slab.h>
26#include <linux/fb.h>
27#include <linux/init.h>
28#include <linux/delay.h>
29#include <linux/platform_device.h>
30
31#include <mach/hardware.h>
32#include <asm/mach-types.h>
33#include <linux/uaccess.h>
34
35struct fb_info	*cfb;
36
37#define CMAP_MAX_SIZE	16
38
39/*
40 * LCD AC Prescale.  This comes from the LCD panel manufacturers specifications.
41 * This determines how many clocks + 1 of CL1 before the M signal toggles.
42 * The number of lines on the display must not be divisible by this number.
43 */
44static unsigned int lcd_ac_prescale = 13;
45
46/*
47 *    Set a single color register. Return != 0 for invalid regno.
48 */
49static int
50clps7111fb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
51		     u_int transp, struct fb_info *info)
52{
53	unsigned int level, mask, shift, pal;
54
55	if (regno >= (1 << info->var.bits_per_pixel))
56		return 1;
57
58	/* gray = 0.30*R + 0.58*G + 0.11*B */
59	level = (red * 77 + green * 151 + blue * 28) >> 20;
60
61	/*
62	 * On an LCD, a high value is dark, while a low value is light.
63	 * So we invert the level.
64	 *
65	 * This isn't true on all machines, so we only do it on EDB7211.
66	 *  --rmk
67	 */
68	if (machine_is_edb7211()) {
69		level = 15 - level;
70	}
71
72	shift = 4 * (regno & 7);
73	level <<= shift;
74	mask  = 15 << shift;
75	level &= mask;
76
77	regno = regno < 8 ? PALLSW : PALMSW;
78
79	pal = clps_readl(regno);
80	pal = (pal & ~mask) | level;
81	clps_writel(pal, regno);
82
83	return 0;
84}
85
86/*
87 * Validate the purposed mode.
88 */
89static int
90clps7111fb_check_var(struct fb_var_screeninfo *var, struct fb_info *info)
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
101	if (var->bits_per_pixel > 4)
102		return -EINVAL;
103
104	return 0;
105}
106
107/*
108 * Set the hardware state.
109 */
110static int
111clps7111fb_set_par(struct fb_info *info)
112{
113	unsigned int lcdcon, syscon, pixclock;
114
115	switch (info->var.bits_per_pixel) {
116	case 1:
117		info->fix.visual = FB_VISUAL_MONO01;
118		break;
119	case 2:
120		info->fix.visual = FB_VISUAL_PSEUDOCOLOR;
121		break;
122	case 4:
123		info->fix.visual = FB_VISUAL_PSEUDOCOLOR;
124		break;
125	}
126
127	info->fix.line_length = info->var.xres_virtual * info->var.bits_per_pixel / 8;
128
129	lcdcon = (info->var.xres_virtual * info->var.yres_virtual * info->var.bits_per_pixel) / 128 - 1;
130	lcdcon |= ((info->var.xres_virtual / 16) - 1) << 13;
131	lcdcon |= lcd_ac_prescale << 25;
132
133	/*
134	 * Calculate pixel prescale value from the pixclock.  This is:
135	 *  36.864MHz / pixclock_mhz - 1.
136	 * However, pixclock is in picoseconds, so this ends up being:
137	 *  36864000 * pixclock_ps / 10^12 - 1
138	 * and this will overflow the 32-bit math.  We perform this as
139	 * (9 * 4096000 == 36864000):
140	 *  pixclock_ps * 9 * (4096000 / 10^12) - 1
141	 */
142	pixclock = 9 * info->var.pixclock / 244140 - 1;
143	lcdcon |= pixclock << 19;
144
145	if (info->var.bits_per_pixel == 4)
146		lcdcon |= LCDCON_GSMD;
147	if (info->var.bits_per_pixel >= 2)
148		lcdcon |= LCDCON_GSEN;
149
150	/*
151	 * LCDCON must only be changed while the LCD is disabled
152	 */
153	syscon = clps_readl(SYSCON1);
154	clps_writel(syscon & ~SYSCON1_LCDEN, SYSCON1);
155	clps_writel(lcdcon, LCDCON);
156	clps_writel(syscon | SYSCON1_LCDEN, SYSCON1);
157	return 0;
158}
159
160static int clps7111fb_blank(int blank, struct fb_info *info)
161{
162	/* Enable/Disable LCD controller. */
163	if (blank)
164		clps_writel(clps_readl(SYSCON1) & ~SYSCON1_LCDEN, SYSCON1);
165	else
166		clps_writel(clps_readl(SYSCON1) | SYSCON1_LCDEN, SYSCON1);
167
168	return 0;
169}
170
171static struct fb_ops clps7111fb_ops = {
172	.owner		= THIS_MODULE,
173	.fb_check_var	= clps7111fb_check_var,
174	.fb_set_par	= clps7111fb_set_par,
175	.fb_setcolreg	= clps7111fb_setcolreg,
176	.fb_blank	= clps7111fb_blank,
177	.fb_fillrect	= cfb_fillrect,
178	.fb_copyarea	= cfb_copyarea,
179	.fb_imageblit	= cfb_imageblit,
180};
181
182static void clps711x_guess_lcd_params(struct fb_info *info)
183{
184	unsigned int lcdcon, syscon, size;
185	unsigned long phys_base = PAGE_OFFSET;
186	void *virt_base = (void *)PAGE_OFFSET;
187
188	info->var.xres_virtual	 = 640;
189	info->var.yres_virtual	 = 240;
190	info->var.bits_per_pixel = 4;
191	info->var.activate	 = FB_ACTIVATE_NOW;
192	info->var.height	 = -1;
193	info->var.width		 = -1;
194	info->var.pixclock	 = 93006; /* 10.752MHz pixel clock */
195
196	/*
197	 * If the LCD controller is already running, decode the values
198	 * in LCDCON to xres/yres/bpp/pixclock/acprescale
199	 */
200	syscon = clps_readl(SYSCON1);
201	if (syscon & SYSCON1_LCDEN) {
202		lcdcon = clps_readl(LCDCON);
203
204		/*
205		 * Decode GSMD and GSEN bits to bits per pixel
206		 */
207		switch (lcdcon & (LCDCON_GSMD | LCDCON_GSEN)) {
208		case LCDCON_GSMD | LCDCON_GSEN:
209			info->var.bits_per_pixel = 4;
210			break;
211
212		case LCDCON_GSEN:
213			info->var.bits_per_pixel = 2;
214			break;
215
216		default:
217			info->var.bits_per_pixel = 1;
218			break;
219		}
220
221		/*
222		 * Decode xres/yres
223		 */
224		info->var.xres_virtual = (((lcdcon >> 13) & 0x3f) + 1) * 16;
225		info->var.yres_virtual = (((lcdcon & 0x1fff) + 1) * 128) /
226					  (info->var.xres_virtual *
227					   info->var.bits_per_pixel);
228
229		/*
230		 * Calculate pixclock
231		 */
232		info->var.pixclock = (((lcdcon >> 19) & 0x3f) + 1) * 244140 / 9;
233
234		/*
235		 * Grab AC prescale
236		 */
237		lcd_ac_prescale = (lcdcon >> 25) & 0x1f;
238	}
239
240	info->var.xres = info->var.xres_virtual;
241	info->var.yres = info->var.yres_virtual;
242	info->var.grayscale = info->var.bits_per_pixel > 1;
243
244	size = info->var.xres * info->var.yres * info->var.bits_per_pixel / 8;
245
246	/*
247	 * Might be worth checking to see if we can use the on-board
248	 * RAM if size here...
249	 * CLPS7110 - no on-board SRAM
250	 * EP7212   - 38400 bytes
251	 */
252	if (size <= 38400) {
253		printk(KERN_INFO "CLPS711xFB: could use on-board SRAM?\n");
254	}
255
256	if ((syscon & SYSCON1_LCDEN) == 0) {
257		/*
258		 * The display isn't running.  Ensure that
259		 * the display memory is empty.
260		 */
261		memset(virt_base, 0, size);
262	}
263
264	info->screen_base    = virt_base;
265	info->fix.smem_start = phys_base;
266	info->fix.smem_len   = PAGE_ALIGN(size);
267	info->fix.type       = FB_TYPE_PACKED_PIXELS;
268}
269
270static int clps711x_fb_probe(struct platform_device *pdev)
271{
272	int err = -ENOMEM;
273
274	if (fb_get_options("clps711xfb", NULL))
275		return -ENODEV;
276
277	cfb = kzalloc(sizeof(*cfb), GFP_KERNEL);
278	if (!cfb)
279		goto out;
280
281	strcpy(cfb->fix.id, "clps711x");
282
283	cfb->fbops		= &clps7111fb_ops;
284	cfb->flags		= FBINFO_DEFAULT;
285
286	clps711x_guess_lcd_params(cfb);
287
288	fb_alloc_cmap(&cfb->cmap, CMAP_MAX_SIZE, 0);
289
290	err = register_framebuffer(cfb);
291
292out:	return err;
293}
294
295static int clps711x_fb_remove(struct platform_device *pdev)
296{
297	unregister_framebuffer(cfb);
298	kfree(cfb);
299
300	return 0;
301}
302
303static struct platform_driver clps711x_fb_driver = {
304	.driver	= {
305		.name	= "video-clps711x",
306	},
307	.probe	= clps711x_fb_probe,
308	.remove	= clps711x_fb_remove,
309};
310module_platform_driver(clps711x_fb_driver);
311
312MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
313MODULE_DESCRIPTION("CLPS711X framebuffer driver");
314MODULE_LICENSE("GPL");
315