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