hecubafb.c

  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 const 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 const 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 = par->info->screen_buffer;
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, struct list_head *pagereflist)
119{
120	hecubafb_dpy_update(info->par);
121}
122
123static void hecubafb_defio_damage_range(struct fb_info *info, off_t off, size_t len)
124{
125	struct hecubafb_par *par = info->par;
126
127	hecubafb_dpy_update(par);
128}
129
130static void hecubafb_defio_damage_area(struct fb_info *info, u32 x, u32 y,
131				       u32 width, u32 height)
132{
133	struct hecubafb_par *par = info->par;
134
135	hecubafb_dpy_update(par);
136}
137
138FB_GEN_DEFAULT_DEFERRED_SYSMEM_OPS(hecubafb,
139				   hecubafb_defio_damage_range,
140				   hecubafb_defio_damage_area)
141
142static const struct fb_ops hecubafb_ops = {
143	.owner	= THIS_MODULE,
144	FB_DEFAULT_DEFERRED_OPS(hecubafb),
145};
146
147static struct fb_deferred_io hecubafb_defio = {
148	.delay		= HZ,
149	.deferred_io	= hecubafb_dpy_deferred_io,
150};
151
152static int hecubafb_probe(struct platform_device *dev)
153{
154	struct fb_info *info;
155	struct hecuba_board *board;
156	int retval = -ENOMEM;
157	int videomemorysize;
158	unsigned char *videomemory;
159	struct hecubafb_par *par;
160
161	/* pick up board specific routines */
162	board = dev->dev.platform_data;
163	if (!board)
164		return -EINVAL;
165
166	/* try to count device specific driver, if can't, platform recalls */
167	if (!try_module_get(board->owner))
168		return -ENODEV;
169
170	videomemorysize = (DPY_W*DPY_H)/8;
171
172	videomemory = vzalloc(videomemorysize);
173	if (!videomemory)
174		goto err_videomem_alloc;
175
176	info = framebuffer_alloc(sizeof(struct hecubafb_par), &dev->dev);
177	if (!info)
178		goto err_fballoc;
179
180	info->screen_buffer = videomemory;
181	info->fbops = &hecubafb_ops;
182
183	info->var = hecubafb_var;
184	info->fix = hecubafb_fix;
185	info->fix.smem_len = videomemorysize;
186	par = info->par;
187	par->info = info;
188	par->board = board;
189	par->send_command = apollo_send_command;
190	par->send_data = apollo_send_data;
191
192	info->flags = FBINFO_VIRTFB;
193
194	info->fbdefio = &hecubafb_defio;
195	fb_deferred_io_init(info);
196
197	retval = register_framebuffer(info);
198	if (retval < 0)
199		goto err_fbreg;
200	platform_set_drvdata(dev, info);
201
202	fb_info(info, "Hecuba frame buffer device, using %dK of video memory\n",
203		videomemorysize >> 10);
204
205	/* this inits the dpy */
206	retval = par->board->init(par);
207	if (retval < 0)
208		goto err_fbreg;
209
210	return 0;
211err_fbreg:
212	framebuffer_release(info);
213err_fballoc:
214	vfree(videomemory);
215err_videomem_alloc:
216	module_put(board->owner);
217	return retval;
218}
219
220static void hecubafb_remove(struct platform_device *dev)
221{
222	struct fb_info *info = platform_get_drvdata(dev);
223
224	if (info) {
225		struct hecubafb_par *par = info->par;
226		fb_deferred_io_cleanup(info);
227		unregister_framebuffer(info);
228		vfree(info->screen_buffer);
229		if (par->board->remove)
230			par->board->remove(par);
231		module_put(par->board->owner);
232		framebuffer_release(info);
233	}
234}
235
236static struct platform_driver hecubafb_driver = {
237	.probe	= hecubafb_probe,
238	.remove	= hecubafb_remove,
239	.driver	= {
240		.name	= "hecubafb",
241	},
242};
243module_platform_driver(hecubafb_driver);
244
245MODULE_DESCRIPTION("fbdev driver for Hecuba/Apollo controller");
246MODULE_AUTHOR("Jaya Kumar");
247MODULE_LICENSE("GPL");