1/*
2 * drivers/input/serio/gscps2.c
3 *
4 * Copyright (c) 2004-2006 Helge Deller <deller@gmx.de>
5 * Copyright (c) 2002 Laurent Canet <canetl@esiee.fr>
6 * Copyright (c) 2002 Thibaut Varene <varenet@parisc-linux.org>
7 *
8 * Pieces of code based on linux-2.4's hp_mouse.c & hp_keyb.c
9 *	Copyright (c) 1999 Alex deVries <alex@onefishtwo.ca>
10 *	Copyright (c) 1999-2000 Philipp Rumpf <prumpf@tux.org>
11 *	Copyright (c) 2000 Xavier Debacker <debackex@esiee.fr>
12 *	Copyright (c) 2000-2001 Thomas Marteau <marteaut@esiee.fr>
13 *
14 * HP GSC PS/2 port driver, found in PA/RISC Workstations
15 *
16 * This file is subject to the terms and conditions of the GNU General Public
17 * License.  See the file "COPYING" in the main directory of this archive
18 * for more details.
19 *
20 * TODO:
21 * - Dino testing (did HP ever shipped a machine on which this port
22 *                 was usable/enabled ?)
23 */
24
25#include <linux/init.h>
26#include <linux/module.h>
27#include <linux/slab.h>
28#include <linux/serio.h>
29#include <linux/input.h>
30#include <linux/interrupt.h>
31#include <linux/spinlock.h>
32#include <linux/delay.h>
33#include <linux/ioport.h>
34
35#include <asm/irq.h>
36#include <asm/io.h>
37#include <asm/parisc-device.h>
38
39MODULE_AUTHOR("Laurent Canet <canetl@esiee.fr>, Thibaut Varene <varenet@parisc-linux.org>, Helge Deller <deller@gmx.de>");
40MODULE_DESCRIPTION("HP GSC PS2 port driver");
41MODULE_LICENSE("GPL");
42
43#define PFX "gscps2.c: "
44
45/*
46 * Driver constants
47 */
48
49/* various constants */
50#define ENABLE			1
51#define DISABLE			0
52
53#define GSC_DINO_OFFSET		0x0800	/* offset for DINO controller versus LASI one */
54
55/* PS/2 IO port offsets */
56#define GSC_ID			0x00	/* device ID offset (see: GSC_ID_XXX) */
57#define GSC_RESET		0x00	/* reset port offset */
58#define GSC_RCVDATA		0x04	/* receive port offset */
59#define GSC_XMTDATA		0x04	/* transmit port offset */
60#define GSC_CONTROL		0x08	/* see: Control register bits */
61#define GSC_STATUS		0x0C	/* see: Status register bits */
62
63/* Control register bits */
64#define GSC_CTRL_ENBL		0x01	/* enable interface */
65#define GSC_CTRL_LPBXR		0x02	/* loopback operation */
66#define GSC_CTRL_DIAG		0x20	/* directly control clock/data line */
67#define GSC_CTRL_DATDIR		0x40	/* data line direct control */
68#define GSC_CTRL_CLKDIR		0x80	/* clock line direct control */
69
70/* Status register bits */
71#define GSC_STAT_RBNE		0x01	/* Receive Buffer Not Empty */
72#define GSC_STAT_TBNE		0x02	/* Transmit Buffer Not Empty */
73#define GSC_STAT_TERR		0x04	/* Timeout Error */
74#define GSC_STAT_PERR		0x08	/* Parity Error */
75#define GSC_STAT_CMPINTR	0x10	/* Composite Interrupt = irq on any port */
76#define GSC_STAT_DATSHD		0x40	/* Data Line Shadow */
77#define GSC_STAT_CLKSHD		0x80	/* Clock Line Shadow */
78
79/* IDs returned by GSC_ID port register */
80#define GSC_ID_KEYBOARD		0	/* device ID values */
81#define GSC_ID_MOUSE		1
82
83
84static irqreturn_t gscps2_interrupt(int irq, void *dev);
85
86#define BUFFER_SIZE 0x0f
87
88/* GSC PS/2 port device struct */
89struct gscps2port {
90	struct list_head node;
91	struct parisc_device *padev;
92	struct serio *port;
93	spinlock_t lock;
94	char *addr;
95	u8 act, append; /* position in buffer[] */
96	struct {
97		u8 data;
98		u8 str;
99	} buffer[BUFFER_SIZE+1];
100	int id;
101};
102
103/*
104 * Various HW level routines
105 */
106
107#define gscps2_readb_input(x)		readb((x)+GSC_RCVDATA)
108#define gscps2_readb_control(x)		readb((x)+GSC_CONTROL)
109#define gscps2_readb_status(x)		readb((x)+GSC_STATUS)
110#define gscps2_writeb_control(x, y)	writeb((x), (y)+GSC_CONTROL)
111
112
113/*
114 * wait_TBE() - wait for Transmit Buffer Empty
115 */
116
117static int wait_TBE(char *addr)
118{
119	int timeout = 25000; /* device is expected to react within 250 msec */
120	while (gscps2_readb_status(addr) & GSC_STAT_TBNE) {
121		if (!--timeout)
122			return 0;	/* This should not happen */
123		udelay(10);
124	}
125	return 1;
126}
127
128
129/*
130 * gscps2_flush() - flush the receive buffer
131 */
132
133static void gscps2_flush(struct gscps2port *ps2port)
134{
135	while (gscps2_readb_status(ps2port->addr) & GSC_STAT_RBNE)
136		gscps2_readb_input(ps2port->addr);
137	ps2port->act = ps2port->append = 0;
138}
139
140/*
141 * gscps2_writeb_output() - write a byte to the port
142 *
143 * returns 1 on success, 0 on error
144 */
145
146static inline int gscps2_writeb_output(struct gscps2port *ps2port, u8 data)
147{
148	unsigned long flags;
149	char *addr = ps2port->addr;
150
151	if (!wait_TBE(addr)) {
152		printk(KERN_DEBUG PFX "timeout - could not write byte %#x\n", data);
153		return 0;
154	}
155
156	while (gscps2_readb_status(ps2port->addr) & GSC_STAT_RBNE)
157		/* wait */;
158
159	spin_lock_irqsave(&ps2port->lock, flags);
160	writeb(data, addr+GSC_XMTDATA);
161	spin_unlock_irqrestore(&ps2port->lock, flags);
162
163	/* this is ugly, but due to timing of the port it seems to be necessary. */
164	mdelay(6);
165
166	/* make sure any received data is returned as fast as possible */
167	/* this is important e.g. when we set the LEDs on the keyboard */
168	gscps2_interrupt(0, NULL);
169
170	return 1;
171}
172
173
174/*
175 * gscps2_enable() - enables or disables the port
176 */
177
178static void gscps2_enable(struct gscps2port *ps2port, int enable)
179{
180	unsigned long flags;
181	u8 data;
182
183	/* now enable/disable the port */
184	spin_lock_irqsave(&ps2port->lock, flags);
185	gscps2_flush(ps2port);
186	data = gscps2_readb_control(ps2port->addr);
187	if (enable)
188		data |= GSC_CTRL_ENBL;
189	else
190		data &= ~GSC_CTRL_ENBL;
191	gscps2_writeb_control(data, ps2port->addr);
192	spin_unlock_irqrestore(&ps2port->lock, flags);
193	wait_TBE(ps2port->addr);
194	gscps2_flush(ps2port);
195}
196
197/*
198 * gscps2_reset() - resets the PS/2 port
199 */
200
201static void gscps2_reset(struct gscps2port *ps2port)
202{
203	char *addr = ps2port->addr;
204	unsigned long flags;
205
206	/* reset the interface */
207	spin_lock_irqsave(&ps2port->lock, flags);
208	gscps2_flush(ps2port);
209	writeb(0xff, addr+GSC_RESET);
210	gscps2_flush(ps2port);
211	spin_unlock_irqrestore(&ps2port->lock, flags);
212}
213
214static LIST_HEAD(ps2port_list);
215
216/**
217 * gscps2_interrupt() - Interruption service routine
218 *
219 * This function reads received PS/2 bytes and processes them on
220 * all interfaces.
221 * The problematic part here is, that the keyboard and mouse PS/2 port
222 * share the same interrupt and it's not possible to send data if any
223 * one of them holds input data. To solve this problem we try to receive
224 * the data as fast as possible and handle the reporting to the upper layer
225 * later.
226 */
227
228static irqreturn_t gscps2_interrupt(int irq, void *dev)
229{
230	struct gscps2port *ps2port;
231
232	list_for_each_entry(ps2port, &ps2port_list, node) {
233
234	  unsigned long flags;
235	  spin_lock_irqsave(&ps2port->lock, flags);
236
237	  while ( (ps2port->buffer[ps2port->append].str =
238		   gscps2_readb_status(ps2port->addr)) & GSC_STAT_RBNE ) {
239		ps2port->buffer[ps2port->append].data =
240				gscps2_readb_input(ps2port->addr);
241		ps2port->append = ((ps2port->append+1) & BUFFER_SIZE);
242	  }
243
244	  spin_unlock_irqrestore(&ps2port->lock, flags);
245
246	} /* list_for_each_entry */
247
248	/* all data was read from the ports - now report the data to upper layer */
249
250	list_for_each_entry(ps2port, &ps2port_list, node) {
251
252	  while (ps2port->act != ps2port->append) {
253
254	    unsigned int rxflags;
255	    u8 data, status;
256
257	    /* Did new data arrived while we read existing data ?
258	       If yes, exit now and let the new irq handler start over again */
259	    if (gscps2_readb_status(ps2port->addr) & GSC_STAT_CMPINTR)
260		return IRQ_HANDLED;
261
262	    status = ps2port->buffer[ps2port->act].str;
263	    data   = ps2port->buffer[ps2port->act].data;
264
265	    ps2port->act = ((ps2port->act+1) & BUFFER_SIZE);
266	    rxflags =	((status & GSC_STAT_TERR) ? SERIO_TIMEOUT : 0 ) |
267			((status & GSC_STAT_PERR) ? SERIO_PARITY  : 0 );
268
269	    serio_interrupt(ps2port->port, data, rxflags);
270
271	  } /* while() */
272
273	} /* list_for_each_entry */
274
275	return IRQ_HANDLED;
276}
277
278
279/*
280 * gscps2_write() - send a byte out through the aux interface.
281 */
282
283static int gscps2_write(struct serio *port, unsigned char data)
284{
285	struct gscps2port *ps2port = port->port_data;
286
287	if (!gscps2_writeb_output(ps2port, data)) {
288		printk(KERN_DEBUG PFX "sending byte %#x failed.\n", data);
289		return -1;
290	}
291	return 0;
292}
293
294/*
295 * gscps2_open() is called when a port is opened by the higher layer.
296 * It resets and enables the port.
297 */
298
299static int gscps2_open(struct serio *port)
300{
301	struct gscps2port *ps2port = port->port_data;
302
303	gscps2_reset(ps2port);
304
305	/* enable it */
306	gscps2_enable(ps2port, ENABLE);
307
308	gscps2_interrupt(0, NULL);
309
310	return 0;
311}
312
313/*
314 * gscps2_close() disables the port
315 */
316
317static void gscps2_close(struct serio *port)
318{
319	struct gscps2port *ps2port = port->port_data;
320	gscps2_enable(ps2port, DISABLE);
321}
322
323/**
324 * gscps2_probe() - Probes PS2 devices
325 * @return: success/error report
326 */
327
328static int gscps2_probe(struct parisc_device *dev)
329{
330	struct gscps2port *ps2port;
331	struct serio *serio;
332	unsigned long hpa = dev->hpa.start;
333	int ret;
334
335	if (!dev->irq)
336		return -ENODEV;
337
338	/* Offset for DINO PS/2. Works with LASI even */
339	if (dev->id.sversion == 0x96)
340		hpa += GSC_DINO_OFFSET;
341
342	ps2port = kzalloc(sizeof(struct gscps2port), GFP_KERNEL);
343	serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
344	if (!ps2port || !serio) {
345		ret = -ENOMEM;
346		goto fail_nomem;
347	}
348
349	dev_set_drvdata(&dev->dev, ps2port);
350
351	ps2port->port = serio;
352	ps2port->padev = dev;
353	ps2port->addr = ioremap_nocache(hpa, GSC_STATUS + 4);
354	spin_lock_init(&ps2port->lock);
355
356	gscps2_reset(ps2port);
357	ps2port->id = readb(ps2port->addr + GSC_ID) & 0x0f;
358
359	snprintf(serio->name, sizeof(serio->name), "gsc-ps2-%s",
360		 (ps2port->id == GSC_ID_KEYBOARD) ? "keyboard" : "mouse");
361	strlcpy(serio->phys, dev_name(&dev->dev), sizeof(serio->phys));
362	serio->id.type		= SERIO_8042;
363	serio->write		= gscps2_write;
364	serio->open		= gscps2_open;
365	serio->close		= gscps2_close;
366	serio->port_data	= ps2port;
367	serio->dev.parent	= &dev->dev;
368
369	ret = -EBUSY;
370	if (request_irq(dev->irq, gscps2_interrupt, IRQF_SHARED, ps2port->port->name, ps2port))
371		goto fail_miserably;
372
373	if (ps2port->id != GSC_ID_KEYBOARD && ps2port->id != GSC_ID_MOUSE) {
374		printk(KERN_WARNING PFX "Unsupported PS/2 port at 0x%08lx (id=%d) ignored\n",
375				hpa, ps2port->id);
376		ret = -ENODEV;
377		goto fail;
378	}
379
380#if 0
381	if (!request_mem_region(hpa, GSC_STATUS + 4, ps2port->port.name))
382		goto fail;
383#endif
384
385	printk(KERN_INFO "serio: %s port at 0x%p irq %d @ %s\n",
386		ps2port->port->name,
387		ps2port->addr,
388		ps2port->padev->irq,
389		ps2port->port->phys);
390
391	serio_register_port(ps2port->port);
392
393	list_add_tail(&ps2port->node, &ps2port_list);
394
395	return 0;
396
397fail:
398	free_irq(dev->irq, ps2port);
399
400fail_miserably:
401	iounmap(ps2port->addr);
402	release_mem_region(dev->hpa.start, GSC_STATUS + 4);
403
404fail_nomem:
405	kfree(ps2port);
406	kfree(serio);
407	return ret;
408}
409
410/**
411 * gscps2_remove() - Removes PS2 devices
412 * @return: success/error report
413 */
414
415static int gscps2_remove(struct parisc_device *dev)
416{
417	struct gscps2port *ps2port = dev_get_drvdata(&dev->dev);
418
419	serio_unregister_port(ps2port->port);
420	free_irq(dev->irq, ps2port);
421	gscps2_flush(ps2port);
422	list_del(&ps2port->node);
423	iounmap(ps2port->addr);
424#if 0
425	release_mem_region(dev->hpa, GSC_STATUS + 4);
426#endif
427	dev_set_drvdata(&dev->dev, NULL);
428	kfree(ps2port);
429	return 0;
430}
431
432
433static struct parisc_device_id gscps2_device_tbl[] = {
434	{ HPHW_FIO, HVERSION_REV_ANY_ID, HVERSION_ANY_ID, 0x00084 }, /* LASI PS/2 */
435#ifdef DINO_TESTED
436	{ HPHW_FIO, HVERSION_REV_ANY_ID, HVERSION_ANY_ID, 0x00096 }, /* DINO PS/2 */
437#endif
438	{ 0, }	/* 0 terminated list */
439};
440MODULE_DEVICE_TABLE(parisc, gscps2_device_tbl);
441
442static struct parisc_driver parisc_ps2_driver = {
443	.name		= "gsc_ps2",
444	.id_table	= gscps2_device_tbl,
445	.probe		= gscps2_probe,
446	.remove		= gscps2_remove,
447};
448
449static int __init gscps2_init(void)
450{
451	register_parisc_driver(&parisc_ps2_driver);
452	return 0;
453}
454
455static void __exit gscps2_exit(void)
456{
457	unregister_parisc_driver(&parisc_ps2_driver);
458}
459
460
461module_init(gscps2_init);
462module_exit(gscps2_exit);
463
464