1/*
2 * linux/drivers/video/hecubafb.c -- FB driver for Hecuba/Apollo controller
3 *
4 * Copyright (C) 2006, Jaya Kumar
5 * This work was sponsored by CIS(M) Sdn Bhd
6 *
7 * This file is subject to the terms and conditions of the GNU General Public
8 * License. See the file COPYING in the main directory of this archive for
9 * more details.
10 *
11 * Layout is based on skeletonfb.c by James Simmons and Geert Uytterhoeven.
12 * This work was possible because of apollo display code from E-Ink's website
13 * http://support.eink.com/community
14 * All information used to write this code is from public material made
15 * available by E-Ink on its support site. Some commands such as 0xA4
16 * were found by looping through cmd=0x00 thru 0xFF and supplying random
17 * values. There are other commands that the display is capable of,
18 * beyond the 5 used here but they are more complex.
19 *
20 * This driver is written to be used with the Hecuba display architecture.
21 * The actual display chip is called Apollo and the interface electronics
22 * it needs is called Hecuba.
23 *
24 * It is intended to be architecture independent. A board specific driver
25 * must be used to perform all the physical IO interactions. An example
26 * is provided as n411.c
27 *
28 */
29
30#include <linux/module.h>
31#include <linux/kernel.h>
32#include <linux/errno.h>
33#include <linux/string.h>
34#include <linux/mm.h>
35#include <linux/vmalloc.h>
36#include <linux/delay.h>
37#include <linux/interrupt.h>
38#include <linux/fb.h>
39#include <linux/init.h>
40#include <linux/platform_device.h>
41#include <linux/list.h>
42#include <linux/uaccess.h>
43
44#include <video/hecubafb.h>
45
46/* Display specific information */
47#define DPY_W 600
48#define DPY_H 800
49
50static struct fb_fix_screeninfo hecubafb_fix = {
51	.id =		"hecubafb",
52	.type =		FB_TYPE_PACKED_PIXELS,
53	.visual =	FB_VISUAL_MONO01,
54	.xpanstep =	0,
55	.ypanstep =	0,
56	.ywrapstep =	0,
57	.line_length =	DPY_W,
58	.accel =	FB_ACCEL_NONE,
59};
60
61static struct fb_var_screeninfo hecubafb_var = {
62	.xres		= DPY_W,
63	.yres		= DPY_H,
64	.xres_virtual	= DPY_W,
65	.yres_virtual	= DPY_H,
66	.bits_per_pixel	= 1,
67	.nonstd		= 1,
68};
69
70/* main hecubafb functions */
71
72static void apollo_send_data(struct hecubafb_par *par, unsigned char data)
73{
74	/* set data */
75	par->board->set_data(par, data);
76
77	/* set DS low */
78	par->board->set_ctl(par, HCB_DS_BIT, 0);
79
80	/* wait for ack */
81	par->board->wait_for_ack(par, 0);
82
83	/* set DS hi */
84	par->board->set_ctl(par, HCB_DS_BIT, 1);
85
86	/* wait for ack to clear */
87	par->board->wait_for_ack(par, 1);
88}
89
90static void apollo_send_command(struct hecubafb_par *par, unsigned char data)
91{
92	/* command so set CD to high */
93	par->board->set_ctl(par, HCB_CD_BIT, 1);
94
95	/* actually strobe with command */
96	apollo_send_data(par, data);
97
98	/* clear CD back to low */
99	par->board->set_ctl(par, HCB_CD_BIT, 0);
100}
101
102static void hecubafb_dpy_update(struct hecubafb_par *par)
103{
104	int i;
105	unsigned char *buf = (unsigned char __force *)par->info->screen_base;
106
107	apollo_send_command(par, APOLLO_START_NEW_IMG);
108
109	for (i=0; i < (DPY_W*DPY_H/8); i++) {
110		apollo_send_data(par, *(buf++));
111	}
112
113	apollo_send_command(par, APOLLO_STOP_IMG_DATA);
114	apollo_send_command(par, APOLLO_DISPLAY_IMG);
115}
116
117/* this is called back from the deferred io workqueue */
118static void hecubafb_dpy_deferred_io(struct fb_info *info,
119				struct list_head *pagelist)
120{
121	hecubafb_dpy_update(info->par);
122}
123
124static void hecubafb_fillrect(struct fb_info *info,
125				   const struct fb_fillrect *rect)
126{
127	struct hecubafb_par *par = info->par;
128
129	sys_fillrect(info, rect);
130
131	hecubafb_dpy_update(par);
132}
133
134static void hecubafb_copyarea(struct fb_info *info,
135				   const struct fb_copyarea *area)
136{
137	struct hecubafb_par *par = info->par;
138
139	sys_copyarea(info, area);
140
141	hecubafb_dpy_update(par);
142}
143
144static void hecubafb_imageblit(struct fb_info *info,
145				const struct fb_image *image)
146{
147	struct hecubafb_par *par = info->par;
148
149	sys_imageblit(info, image);
150
151	hecubafb_dpy_update(par);
152}
153
154/*
155 * this is the slow path from userspace. they can seek and write to
156 * the fb. it's inefficient to do anything less than a full screen draw
157 */
158static ssize_t hecubafb_write(struct fb_info *info, const char __user *buf,
159				size_t count, loff_t *ppos)
160{
161	struct hecubafb_par *par = info->par;
162	unsigned long p = *ppos;
163	void *dst;
164	int err = 0;
165	unsigned long total_size;
166
167	if (info->state != FBINFO_STATE_RUNNING)
168		return -EPERM;
169
170	total_size = info->fix.smem_len;
171
172	if (p > total_size)
173		return -EFBIG;
174
175	if (count > total_size) {
176		err = -EFBIG;
177		count = total_size;
178	}
179
180	if (count + p > total_size) {
181		if (!err)
182			err = -ENOSPC;
183
184		count = total_size - p;
185	}
186
187	dst = (void __force *) (info->screen_base + p);
188
189	if (copy_from_user(dst, buf, count))
190		err = -EFAULT;
191
192	if  (!err)
193		*ppos += count;
194
195	hecubafb_dpy_update(par);
196
197	return (err) ? err : count;
198}
199
200static struct fb_ops hecubafb_ops = {
201	.owner		= THIS_MODULE,
202	.fb_read        = fb_sys_read,
203	.fb_write	= hecubafb_write,
204	.fb_fillrect	= hecubafb_fillrect,
205	.fb_copyarea	= hecubafb_copyarea,
206	.fb_imageblit	= hecubafb_imageblit,
207};
208
209static struct fb_deferred_io hecubafb_defio = {
210	.delay		= HZ,
211	.deferred_io	= hecubafb_dpy_deferred_io,
212};
213
214static int hecubafb_probe(struct platform_device *dev)
215{
216	struct fb_info *info;
217	struct hecuba_board *board;
218	int retval = -ENOMEM;
219	int videomemorysize;
220	unsigned char *videomemory;
221	struct hecubafb_par *par;
222
223	/* pick up board specific routines */
224	board = dev->dev.platform_data;
225	if (!board)
226		return -EINVAL;
227
228	/* try to count device specific driver, if can't, platform recalls */
229	if (!try_module_get(board->owner))
230		return -ENODEV;
231
232	videomemorysize = (DPY_W*DPY_H)/8;
233
234	videomemory = vzalloc(videomemorysize);
235	if (!videomemory)
236		goto err_videomem_alloc;
237
238	info = framebuffer_alloc(sizeof(struct hecubafb_par), &dev->dev);
239	if (!info)
240		goto err_fballoc;
241
242	info->screen_base = (char __force __iomem *)videomemory;
243	info->fbops = &hecubafb_ops;
244
245	info->var = hecubafb_var;
246	info->fix = hecubafb_fix;
247	info->fix.smem_len = videomemorysize;
248	par = info->par;
249	par->info = info;
250	par->board = board;
251	par->send_command = apollo_send_command;
252	par->send_data = apollo_send_data;
253
254	info->flags = FBINFO_FLAG_DEFAULT | FBINFO_VIRTFB;
255
256	info->fbdefio = &hecubafb_defio;
257	fb_deferred_io_init(info);
258
259	retval = register_framebuffer(info);
260	if (retval < 0)
261		goto err_fbreg;
262	platform_set_drvdata(dev, info);
263
264	fb_info(info, "Hecuba frame buffer device, using %dK of video memory\n",
265		videomemorysize >> 10);
266
267	/* this inits the dpy */
268	retval = par->board->init(par);
269	if (retval < 0)
270		goto err_fbreg;
271
272	return 0;
273err_fbreg:
274	framebuffer_release(info);
275err_fballoc:
276	vfree(videomemory);
277err_videomem_alloc:
278	module_put(board->owner);
279	return retval;
280}
281
282static int hecubafb_remove(struct platform_device *dev)
283{
284	struct fb_info *info = platform_get_drvdata(dev);
285
286	if (info) {
287		struct hecubafb_par *par = info->par;
288		fb_deferred_io_cleanup(info);
289		unregister_framebuffer(info);
290		vfree((void __force *)info->screen_base);
291		if (par->board->remove)
292			par->board->remove(par);
293		module_put(par->board->owner);
294		framebuffer_release(info);
295	}
296	return 0;
297}
298
299static struct platform_driver hecubafb_driver = {
300	.probe	= hecubafb_probe,
301	.remove = hecubafb_remove,
302	.driver	= {
303		.name	= "hecubafb",
304	},
305};
306module_platform_driver(hecubafb_driver);
307
308MODULE_DESCRIPTION("fbdev driver for Hecuba/Apollo controller");
309MODULE_AUTHOR("Jaya Kumar");
310MODULE_LICENSE("GPL");
311