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 __iomem *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 __iomem *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 __iomem *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(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	unsigned long flags;
204
205	/* reset the interface */
206	spin_lock_irqsave(&ps2port->lock, flags);
207	gscps2_flush(ps2port);
208	writeb(0xff, ps2port->addr + GSC_RESET);
209	gscps2_flush(ps2port);
210	spin_unlock_irqrestore(&ps2port->lock, flags);
211}
212
213static LIST_HEAD(ps2port_list);
214
215/**
216 * gscps2_interrupt() - Interruption service routine
217 *
218 * This function reads received PS/2 bytes and processes them on
219 * all interfaces.
220 * The problematic part here is, that the keyboard and mouse PS/2 port
221 * share the same interrupt and it's not possible to send data if any
222 * one of them holds input data. To solve this problem we try to receive
223 * the data as fast as possible and handle the reporting to the upper layer
224 * later.
225 */
226
227static irqreturn_t gscps2_interrupt(int irq, void *dev)
228{
229	struct gscps2port *ps2port;
230
231	list_for_each_entry(ps2port, &ps2port_list, node) {
232
233	  unsigned long flags;
234	  spin_lock_irqsave(&ps2port->lock, flags);
235
236	  while ( (ps2port->buffer[ps2port->append].str =
237		   gscps2_readb_status(ps2port->addr)) & GSC_STAT_RBNE ) {
238		ps2port->buffer[ps2port->append].data =
239				gscps2_readb_input(ps2port->addr);
240		ps2port->append = ((ps2port->append+1) & BUFFER_SIZE);
241	  }
242
243	  spin_unlock_irqrestore(&ps2port->lock, flags);
244
245	} /* list_for_each_entry */
246
247	/* all data was read from the ports - now report the data to upper layer */
248
249	list_for_each_entry(ps2port, &ps2port_list, node) {
250
251	  while (ps2port->act != ps2port->append) {
252
253	    unsigned int rxflags;
254	    u8 data, status;
255
256	    /* Did new data arrived while we read existing data ?
257	       If yes, exit now and let the new irq handler start over again */
258	    if (gscps2_readb_status(ps2port->addr) & GSC_STAT_CMPINTR)
259		return IRQ_HANDLED;
260
261	    status = ps2port->buffer[ps2port->act].str;
262	    data   = ps2port->buffer[ps2port->act].data;
263
264	    ps2port->act = ((ps2port->act+1) & BUFFER_SIZE);
265	    rxflags =	((status & GSC_STAT_TERR) ? SERIO_TIMEOUT : 0 ) |
266			((status & GSC_STAT_PERR) ? SERIO_PARITY  : 0 );
267
268	    serio_interrupt(ps2port->port, data, rxflags);
269
270	  } /* while() */
271
272	} /* list_for_each_entry */
273
274	return IRQ_HANDLED;
275}
276
277
278/*
279 * gscps2_write() - send a byte out through the aux interface.
280 */
281
282static int gscps2_write(struct serio *port, unsigned char data)
283{
284	struct gscps2port *ps2port = port->port_data;
285
286	if (!gscps2_writeb_output(ps2port, data)) {
287		printk(KERN_DEBUG PFX "sending byte %#x failed.\n", data);
288		return -1;
289	}
290	return 0;
291}
292
293/*
294 * gscps2_open() is called when a port is opened by the higher layer.
295 * It resets and enables the port.
296 */
297
298static int gscps2_open(struct serio *port)
299{
300	struct gscps2port *ps2port = port->port_data;
301
302	gscps2_reset(ps2port);
303
304	/* enable it */
305	gscps2_enable(ps2port, ENABLE);
306
307	gscps2_interrupt(0, NULL);
308
309	return 0;
310}
311
312/*
313 * gscps2_close() disables the port
314 */
315
316static void gscps2_close(struct serio *port)
317{
318	struct gscps2port *ps2port = port->port_data;
319	gscps2_enable(ps2port, DISABLE);
320}
321
322/**
323 * gscps2_probe() - Probes PS2 devices
324 * @return: success/error report
325 */
326
327static int __init gscps2_probe(struct parisc_device *dev)
328{
329	struct gscps2port *ps2port;
330	struct serio *serio;
331	unsigned long hpa = dev->hpa.start;
332	int ret;
333
334	if (!dev->irq)
335		return -ENODEV;
336
337	/* Offset for DINO PS/2. Works with LASI even */
338	if (dev->id.sversion == 0x96)
339		hpa += GSC_DINO_OFFSET;
340
341	ps2port = kzalloc(sizeof(struct gscps2port), GFP_KERNEL);
342	serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
343	if (!ps2port || !serio) {
344		ret = -ENOMEM;
345		goto fail_nomem;
346	}
347
348	dev_set_drvdata(&dev->dev, ps2port);
349
350	ps2port->port = serio;
351	ps2port->padev = dev;
352	ps2port->addr = ioremap(hpa, GSC_STATUS + 4);
353	if (!ps2port->addr) {
354		ret = -ENOMEM;
355		goto fail_nomem;
356	}
357	spin_lock_init(&ps2port->lock);
358
359	gscps2_reset(ps2port);
360	ps2port->id = readb(ps2port->addr + GSC_ID) & 0x0f;
361
362	snprintf(serio->name, sizeof(serio->name), "gsc-ps2-%s",
363		 (ps2port->id == GSC_ID_KEYBOARD) ? "keyboard" : "mouse");
364	strscpy(serio->phys, dev_name(&dev->dev), sizeof(serio->phys));
365	serio->id.type		= SERIO_8042;
366	serio->write		= gscps2_write;
367	serio->open		= gscps2_open;
368	serio->close		= gscps2_close;
369	serio->port_data	= ps2port;
370	serio->dev.parent	= &dev->dev;
371
372	ret = -EBUSY;
373	if (request_irq(dev->irq, gscps2_interrupt, IRQF_SHARED, ps2port->port->name, ps2port))
374		goto fail_miserably;
375
376	if (ps2port->id != GSC_ID_KEYBOARD && ps2port->id != GSC_ID_MOUSE) {
377		printk(KERN_WARNING PFX "Unsupported PS/2 port at 0x%08lx (id=%d) ignored\n",
378				hpa, ps2port->id);
379		ret = -ENODEV;
380		goto fail;
381	}
382
383#if 0
384	if (!request_mem_region(hpa, GSC_STATUS + 4, ps2port->port.name))
385		goto fail;
386#endif
387
388	pr_info("serio: %s port at 0x%08lx irq %d @ %s\n",
389		ps2port->port->name,
390		hpa,
391		ps2port->padev->irq,
392		ps2port->port->phys);
393
394	serio_register_port(ps2port->port);
395
396	list_add_tail(&ps2port->node, &ps2port_list);
397
398	return 0;
399
400fail:
401	free_irq(dev->irq, ps2port);
402
403fail_miserably:
404	iounmap(ps2port->addr);
405	release_mem_region(dev->hpa.start, GSC_STATUS + 4);
406
407fail_nomem:
408	kfree(ps2port);
409	kfree(serio);
410	return ret;
411}
412
413/**
414 * gscps2_remove() - Removes PS2 devices
415 * @return: success/error report
416 */
417
418static void __exit gscps2_remove(struct parisc_device *dev)
419{
420	struct gscps2port *ps2port = dev_get_drvdata(&dev->dev);
421
422	serio_unregister_port(ps2port->port);
423	free_irq(dev->irq, ps2port);
424	gscps2_flush(ps2port);
425	list_del(&ps2port->node);
426	iounmap(ps2port->addr);
427#if 0
428	release_mem_region(dev->hpa, GSC_STATUS + 4);
429#endif
430	dev_set_drvdata(&dev->dev, NULL);
431	kfree(ps2port);
432}
433
434
435static const struct parisc_device_id gscps2_device_tbl[] __initconst = {
436	{ HPHW_FIO, HVERSION_REV_ANY_ID, HVERSION_ANY_ID, 0x00084 }, /* LASI PS/2 */
437#ifdef DINO_TESTED
438	{ HPHW_FIO, HVERSION_REV_ANY_ID, HVERSION_ANY_ID, 0x00096 }, /* DINO PS/2 */
439#endif
440	{ 0, }	/* 0 terminated list */
441};
442MODULE_DEVICE_TABLE(parisc, gscps2_device_tbl);
443
444static struct parisc_driver parisc_ps2_driver __refdata = {
445	.name		= "gsc_ps2",
446	.id_table	= gscps2_device_tbl,
447	.probe		= gscps2_probe,
448	.remove		= __exit_p(gscps2_remove),
449};
450
451static int __init gscps2_init(void)
452{
453	register_parisc_driver(&parisc_ps2_driver);
454	return 0;
455}
456
457static void __exit gscps2_exit(void)
458{
459	unregister_parisc_driver(&parisc_ps2_driver);
460}
461
462
463module_init(gscps2_init);
464module_exit(gscps2_exit);
465
466