1/*
2 * linux/drivers/video/hecubafb.c -- FB driver for Hecuba 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 controller
21 * board, and tested with the EInk 800x600 display in 1 bit mode.
22 * The interface between Hecuba and the host is TTL based GPIO. The
23 * GPIO requirements are 8 writable data lines and 6 lines for control.
24 * Only 4 of the controls are actually used here but 6 for future use.
25 * The driver requires the IO addresses for data and control GPIO at
26 * load time. It is also possible to use this display with a standard
27 * PC parallel port.
28 *
29 * General notes:
30 * - User must set hecubafb_enable=1 to enable it
31 * - User must set dio_addr=0xIOADDR cio_addr=0xIOADDR c2io_addr=0xIOADDR
32 *
33 */
34
35#include <linux/module.h>
36#include <linux/kernel.h>
37#include <linux/errno.h>
38#include <linux/string.h>
39#include <linux/mm.h>
40#include <linux/slab.h>
41#include <linux/vmalloc.h>
42#include <linux/delay.h>
43#include <linux/interrupt.h>
44#include <linux/fb.h>
45#include <linux/init.h>
46#include <linux/platform_device.h>
47#include <linux/list.h>
48#include <asm/uaccess.h>
49
50/* Apollo controller specific defines */
51#define APOLLO_START_NEW_IMG	0xA0
52#define APOLLO_STOP_IMG_DATA	0xA1
53#define APOLLO_DISPLAY_IMG	0xA2
54#define APOLLO_ERASE_DISPLAY	0xA3
55#define APOLLO_INIT_DISPLAY	0xA4
56
57/* Hecuba interface specific defines */
58/* WUP is inverted, CD is inverted, DS is inverted */
59#define HCB_NWUP_BIT	0x01
60#define HCB_NDS_BIT 	0x02
61#define HCB_RW_BIT 	0x04
62#define HCB_NCD_BIT 	0x08
63#define HCB_ACK_BIT 	0x80
64
65/* Display specific information */
66#define DPY_W 600
67#define DPY_H 800
68
69struct hecubafb_par {
70	unsigned long dio_addr;
71	unsigned long cio_addr;
72	unsigned long c2io_addr;
73	unsigned char ctl;
74	struct fb_info *info;
75	unsigned int irq;
76};
77
78static struct fb_fix_screeninfo hecubafb_fix __devinitdata = {
79	.id =		"hecubafb",
80	.type =		FB_TYPE_PACKED_PIXELS,
81	.visual =	FB_VISUAL_MONO01,
82	.xpanstep =	0,
83	.ypanstep =	0,
84	.ywrapstep =	0,
85	.accel =	FB_ACCEL_NONE,
86};
87
88static struct fb_var_screeninfo hecubafb_var __devinitdata = {
89	.xres		= DPY_W,
90	.yres		= DPY_H,
91	.xres_virtual	= DPY_W,
92	.yres_virtual	= DPY_H,
93	.bits_per_pixel	= 1,
94	.nonstd		= 1,
95};
96
97static unsigned long dio_addr;
98static unsigned long cio_addr;
99static unsigned long c2io_addr;
100static unsigned long splashval;
101static unsigned int nosplash;
102static unsigned int hecubafb_enable;
103static unsigned int irq;
104
105static DECLARE_WAIT_QUEUE_HEAD(hecubafb_waitq);
106
107static void hcb_set_ctl(struct hecubafb_par *par)
108{
109	outb(par->ctl, par->cio_addr);
110}
111
112static unsigned char hcb_get_ctl(struct hecubafb_par *par)
113{
114	return inb(par->c2io_addr);
115}
116
117static void hcb_set_data(struct hecubafb_par *par, unsigned char value)
118{
119	outb(value, par->dio_addr);
120}
121
122static int __devinit apollo_init_control(struct hecubafb_par *par)
123{
124	unsigned char ctl;
125	/* for init, we want the following setup to be set:
126	WUP = lo
127	ACK = hi
128	DS = hi
129	RW = hi
130	CD = lo
131	*/
132
133	/* write WUP to lo, DS to hi, RW to hi, CD to lo */
134	par->ctl = HCB_NWUP_BIT | HCB_RW_BIT | HCB_NCD_BIT ;
135	par->ctl &= ~HCB_NDS_BIT;
136	hcb_set_ctl(par);
137
138	/* check ACK is not lo */
139	ctl = hcb_get_ctl(par);
140	if ((ctl & HCB_ACK_BIT)) {
141		printk(KERN_ERR "Fail because ACK is already low\n");
142		return -ENXIO;
143	}
144
145	return 0;
146}
147
148static void hcb_wait_for_ack(struct hecubafb_par *par)
149{
150
151	int timeout;
152	unsigned char ctl;
153
154	timeout=500;
155	do {
156		ctl = hcb_get_ctl(par);
157		if ((ctl & HCB_ACK_BIT))
158			return;
159		udelay(1);
160	} while (timeout--);
161	printk(KERN_ERR "timed out waiting for ack\n");
162}
163
164static void hcb_wait_for_ack_clear(struct hecubafb_par *par)
165{
166
167	int timeout;
168	unsigned char ctl;
169
170	timeout=500;
171	do {
172		ctl = hcb_get_ctl(par);
173		if (!(ctl & HCB_ACK_BIT))
174			return;
175		udelay(1);
176	} while (timeout--);
177	printk(KERN_ERR "timed out waiting for clear\n");
178}
179
180static void apollo_send_data(struct hecubafb_par *par, unsigned char data)
181{
182	/* set data */
183	hcb_set_data(par, data);
184
185	/* set DS low */
186	par->ctl |= HCB_NDS_BIT;
187	hcb_set_ctl(par);
188
189	hcb_wait_for_ack(par);
190
191	/* set DS hi */
192	par->ctl &= ~(HCB_NDS_BIT);
193	hcb_set_ctl(par);
194
195	hcb_wait_for_ack_clear(par);
196}
197
198static void apollo_send_command(struct hecubafb_par *par, unsigned char data)
199{
200	/* command so set CD to high */
201	par->ctl &= ~(HCB_NCD_BIT);
202	hcb_set_ctl(par);
203
204	/* actually strobe with command */
205	apollo_send_data(par, data);
206
207	/* clear CD back to low */
208	par->ctl |= (HCB_NCD_BIT);
209	hcb_set_ctl(par);
210}
211
212/* main hecubafb functions */
213
214static void hecubafb_dpy_update(struct hecubafb_par *par)
215{
216	int i;
217	unsigned char *buf = (unsigned char __force *)par->info->screen_base;
218
219	apollo_send_command(par, 0xA0);
220
221	for (i=0; i < (DPY_W*DPY_H/8); i++) {
222		apollo_send_data(par, *(buf++));
223	}
224
225	apollo_send_command(par, 0xA1);
226	apollo_send_command(par, 0xA2);
227}
228
229/* this is called back from the deferred io workqueue */
230static void hecubafb_dpy_deferred_io(struct fb_info *info,
231				struct list_head *pagelist)
232{
233	hecubafb_dpy_update(info->par);
234}
235
236static void hecubafb_fillrect(struct fb_info *info,
237				   const struct fb_fillrect *rect)
238{
239	struct hecubafb_par *par = info->par;
240
241	sys_fillrect(info, rect);
242
243	hecubafb_dpy_update(par);
244}
245
246static void hecubafb_copyarea(struct fb_info *info,
247				   const struct fb_copyarea *area)
248{
249	struct hecubafb_par *par = info->par;
250
251	sys_copyarea(info, area);
252
253	hecubafb_dpy_update(par);
254}
255
256static void hecubafb_imageblit(struct fb_info *info,
257				const struct fb_image *image)
258{
259	struct hecubafb_par *par = info->par;
260
261	sys_imageblit(info, image);
262
263	hecubafb_dpy_update(par);
264}
265
266/*
267 * this is the slow path from userspace. they can seek and write to
268 * the fb. it's inefficient to do anything less than a full screen draw
269 */
270static ssize_t hecubafb_write(struct fb_info *info, const char __user *buf,
271				size_t count, loff_t *ppos)
272{
273	unsigned long p;
274	int err=-EINVAL;
275	struct hecubafb_par *par;
276	unsigned int xres;
277	unsigned int fbmemlength;
278
279	p = *ppos;
280	par = info->par;
281	xres = info->var.xres;
282	fbmemlength = (xres * info->var.yres)/8;
283
284	if (p > fbmemlength)
285		return -ENOSPC;
286
287	err = 0;
288	if ((count + p) > fbmemlength) {
289		count = fbmemlength - p;
290		err = -ENOSPC;
291	}
292
293	if (count) {
294		char *base_addr;
295
296		base_addr = (char __force *)info->screen_base;
297		count -= copy_from_user(base_addr + p, buf, count);
298		*ppos += count;
299		err = -EFAULT;
300	}
301
302	hecubafb_dpy_update(par);
303
304	if (count)
305		return count;
306
307	return err;
308}
309
310static struct fb_ops hecubafb_ops = {
311	.owner		= THIS_MODULE,
312	.fb_read        = fb_sys_read,
313	.fb_write	= hecubafb_write,
314	.fb_fillrect	= hecubafb_fillrect,
315	.fb_copyarea	= hecubafb_copyarea,
316	.fb_imageblit	= hecubafb_imageblit,
317};
318
319static struct fb_deferred_io hecubafb_defio = {
320	.delay		= HZ,
321	.deferred_io	= hecubafb_dpy_deferred_io,
322};
323
324static int __devinit hecubafb_probe(struct platform_device *dev)
325{
326	struct fb_info *info;
327	int retval = -ENOMEM;
328	int videomemorysize;
329	unsigned char *videomemory;
330	struct hecubafb_par *par;
331
332	videomemorysize = (DPY_W*DPY_H)/8;
333
334	if (!(videomemory = vmalloc(videomemorysize)))
335		return retval;
336
337	memset(videomemory, 0, videomemorysize);
338
339	info = framebuffer_alloc(sizeof(struct hecubafb_par), &dev->dev);
340	if (!info)
341		goto err;
342
343	info->screen_base = (char __iomem *) videomemory;
344	info->fbops = &hecubafb_ops;
345
346	info->var = hecubafb_var;
347	info->fix = hecubafb_fix;
348	info->fix.smem_len = videomemorysize;
349	par = info->par;
350	par->info = info;
351
352	if (!dio_addr || !cio_addr || !c2io_addr) {
353		printk(KERN_WARNING "no IO addresses supplied\n");
354		goto err1;
355	}
356	par->dio_addr = dio_addr;
357	par->cio_addr = cio_addr;
358	par->c2io_addr = c2io_addr;
359	info->flags = FBINFO_FLAG_DEFAULT;
360
361	info->fbdefio = &hecubafb_defio;
362	fb_deferred_io_init(info);
363
364	retval = register_framebuffer(info);
365	if (retval < 0)
366		goto err1;
367	platform_set_drvdata(dev, info);
368
369	printk(KERN_INFO
370	       "fb%d: Hecuba frame buffer device, using %dK of video memory\n",
371	       info->node, videomemorysize >> 10);
372
373	/* this inits the dpy */
374	apollo_init_control(par);
375
376	apollo_send_command(par, APOLLO_INIT_DISPLAY);
377	apollo_send_data(par, 0x81);
378
379	/* have to wait while display resets */
380	udelay(1000);
381
382	/* if we were told to splash the screen, we just clear it */
383	if (!nosplash) {
384		apollo_send_command(par, APOLLO_ERASE_DISPLAY);
385		apollo_send_data(par, splashval);
386	}
387
388	return 0;
389err1:
390	framebuffer_release(info);
391err:
392	vfree(videomemory);
393	return retval;
394}
395
396static int __devexit hecubafb_remove(struct platform_device *dev)
397{
398	struct fb_info *info = platform_get_drvdata(dev);
399
400	if (info) {
401		fb_deferred_io_cleanup(info);
402		unregister_framebuffer(info);
403		vfree((void __force *)info->screen_base);
404		framebuffer_release(info);
405	}
406	return 0;
407}
408
409static struct platform_driver hecubafb_driver = {
410	.probe	= hecubafb_probe,
411	.remove = hecubafb_remove,
412	.driver	= {
413		.name	= "hecubafb",
414	},
415};
416
417static struct platform_device *hecubafb_device;
418
419static int __init hecubafb_init(void)
420{
421	int ret;
422
423	if (!hecubafb_enable) {
424		printk(KERN_ERR "Use hecubafb_enable to enable the device\n");
425		return -ENXIO;
426	}
427
428	ret = platform_driver_register(&hecubafb_driver);
429	if (!ret) {
430		hecubafb_device = platform_device_alloc("hecubafb", 0);
431		if (hecubafb_device)
432			ret = platform_device_add(hecubafb_device);
433		else
434			ret = -ENOMEM;
435
436		if (ret) {
437			platform_device_put(hecubafb_device);
438			platform_driver_unregister(&hecubafb_driver);
439		}
440	}
441	return ret;
442
443}
444
445static void __exit hecubafb_exit(void)
446{
447	platform_device_unregister(hecubafb_device);
448	platform_driver_unregister(&hecubafb_driver);
449}
450
451module_param(nosplash, uint, 0);
452MODULE_PARM_DESC(nosplash, "Disable doing the splash screen");
453module_param(hecubafb_enable, uint, 0);
454MODULE_PARM_DESC(hecubafb_enable, "Enable communication with Hecuba board");
455module_param(dio_addr, ulong, 0);
456MODULE_PARM_DESC(dio_addr, "IO address for data, eg: 0x480");
457module_param(cio_addr, ulong, 0);
458MODULE_PARM_DESC(cio_addr, "IO address for control, eg: 0x400");
459module_param(c2io_addr, ulong, 0);
460MODULE_PARM_DESC(c2io_addr, "IO address for secondary control, eg: 0x408");
461module_param(splashval, ulong, 0);
462MODULE_PARM_DESC(splashval, "Splash pattern: 0x00 is black, 0x01 is white");
463module_param(irq, uint, 0);
464MODULE_PARM_DESC(irq, "IRQ for the Hecuba board");
465
466module_init(hecubafb_init);
467module_exit(hecubafb_exit);
468
469MODULE_DESCRIPTION("fbdev driver for Hecuba board");
470MODULE_AUTHOR("Jaya Kumar");
471MODULE_LICENSE("GPL");
472