gscps2.c

  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	char __iomem *addr = ps2port->addr;
149
150	if (!wait_TBE(addr)) {
151		printk(KERN_DEBUG PFX "timeout - could not write byte %#x\n", data);
152		return 0;
153	}
154
155	while (gscps2_readb_status(addr) & GSC_STAT_RBNE)
156		/* wait */;
157
158	scoped_guard(spinlock_irqsave, &ps2port->lock)
159		writeb(data, addr+GSC_XMTDATA);
160
161	/* this is ugly, but due to timing of the port it seems to be necessary. */
162	mdelay(6);
163
164	/* make sure any received data is returned as fast as possible */
165	/* this is important e.g. when we set the LEDs on the keyboard */
166	gscps2_interrupt(0, NULL);
167
168	return 1;
169}
170
171
172/*
173 * gscps2_enable() - enables or disables the port
174 */
175
176static void gscps2_enable(struct gscps2port *ps2port, int enable)
177{
178	u8 data;
179
180	/* now enable/disable the port */
181	scoped_guard(spinlock_irqsave, &ps2port->lock) {
182		gscps2_flush(ps2port);
183		data = gscps2_readb_control(ps2port->addr);
184		if (enable)
185			data |= GSC_CTRL_ENBL;
186		else
187			data &= ~GSC_CTRL_ENBL;
188		gscps2_writeb_control(data, ps2port->addr);
189	}
190
191	wait_TBE(ps2port->addr);
192	gscps2_flush(ps2port);
193}
194
195/*
196 * gscps2_reset() - resets the PS/2 port
197 */
198
199static void gscps2_reset(struct gscps2port *ps2port)
200{
201	/* reset the interface */
202	guard(spinlock_irqsave)(&ps2port->lock);
203	gscps2_flush(ps2port);
204	writeb(0xff, ps2port->addr + GSC_RESET);
205	gscps2_flush(ps2port);
206}
207
208static LIST_HEAD(ps2port_list);
209
210static void gscps2_read_data(struct gscps2port *ps2port)
211{
212	u8 status;
213
214	do {
215		status = gscps2_readb_status(ps2port->addr);
216		if (!(status & GSC_STAT_RBNE))
217			break;
218
219		ps2port->buffer[ps2port->append].str = status;
220		ps2port->buffer[ps2port->append].data =
221				gscps2_readb_input(ps2port->addr);
222	} while (true);
223}
224
225static bool gscps2_report_data(struct gscps2port *ps2port)
226{
227	unsigned int rxflags;
228	u8 data, status;
229
230	while (ps2port->act != ps2port->append) {
231		/*
232		 * Did new data arrived while we read existing data ?
233		 * If yes, exit now and let the new irq handler start
234		 * over again.
235		 */
236		if (gscps2_readb_status(ps2port->addr) & GSC_STAT_CMPINTR)
237			return true;
238
239		status = ps2port->buffer[ps2port->act].str;
240		data   = ps2port->buffer[ps2port->act].data;
241
242		ps2port->act = (ps2port->act + 1) & BUFFER_SIZE;
243		rxflags = ((status & GSC_STAT_TERR) ? SERIO_TIMEOUT : 0 ) |
244			  ((status & GSC_STAT_PERR) ? SERIO_PARITY  : 0 );
245
246		serio_interrupt(ps2port->port, data, rxflags);
247	}
248
249	return false;
250}
251
252/**
253 * gscps2_interrupt() - Interruption service routine
254 * @irq: interrupt number which triggered (unused)
255 * @dev: device pointer (unused)
256 *
257 * This function reads received PS/2 bytes and processes them on
258 * all interfaces.
259 * The problematic part here is, that the keyboard and mouse PS/2 port
260 * share the same interrupt and it's not possible to send data if any
261 * one of them holds input data. To solve this problem we try to receive
262 * the data as fast as possible and handle the reporting to the upper layer
263 * later.
264 */
265
266static irqreturn_t gscps2_interrupt(int irq, void *dev)
267{
268	struct gscps2port *ps2port;
269
270	list_for_each_entry(ps2port, &ps2port_list, node) {
271		guard(spinlock_irqsave)(&ps2port->lock);
272
273		gscps2_read_data(ps2port);
274	} /* list_for_each_entry */
275
276	/* all data was read from the ports - now report the data to upper layer */
277	list_for_each_entry(ps2port, &ps2port_list, node) {
278		if (gscps2_report_data(ps2port)) {
279			/* More data ready - break early to restart interrupt */
280			break;
281		}
282	}
283
284	return IRQ_HANDLED;
285}
286
287
288/*
289 * gscps2_write() - send a byte out through the aux interface.
290 */
291
292static int gscps2_write(struct serio *port, unsigned char data)
293{
294	struct gscps2port *ps2port = port->port_data;
295
296	if (!gscps2_writeb_output(ps2port, data)) {
297		printk(KERN_DEBUG PFX "sending byte %#x failed.\n", data);
298		return -1;
299	}
300	return 0;
301}
302
303/*
304 * gscps2_open() is called when a port is opened by the higher layer.
305 * It resets and enables the port.
306 */
307
308static int gscps2_open(struct serio *port)
309{
310	struct gscps2port *ps2port = port->port_data;
311
312	gscps2_reset(ps2port);
313
314	/* enable it */
315	gscps2_enable(ps2port, ENABLE);
316
317	gscps2_interrupt(0, NULL);
318
319	return 0;
320}
321
322/*
323 * gscps2_close() disables the port
324 */
325
326static void gscps2_close(struct serio *port)
327{
328	struct gscps2port *ps2port = port->port_data;
329	gscps2_enable(ps2port, DISABLE);
330}
331
332/**
333 * gscps2_probe() - Probes PS2 devices
334 * @dev: pointer to parisc_device struct which will be probed
335 *
336 * @return: success/error report
337 */
338
339static int __init gscps2_probe(struct parisc_device *dev)
340{
341	struct gscps2port *ps2port;
342	struct serio *serio;
343	unsigned long hpa = dev->hpa.start;
344	int ret;
345
346	if (!dev->irq)
347		return -ENODEV;
348
349	/* Offset for DINO PS/2. Works with LASI even */
350	if (dev->id.sversion == 0x96)
351		hpa += GSC_DINO_OFFSET;
352
353	ps2port = kzalloc(sizeof(*ps2port), GFP_KERNEL);
354	serio = kzalloc(sizeof(*serio), GFP_KERNEL);
355	if (!ps2port || !serio) {
356		ret = -ENOMEM;
357		goto fail_nomem;
358	}
359
360	dev_set_drvdata(&dev->dev, ps2port);
361
362	ps2port->port = serio;
363	ps2port->padev = dev;
364	ps2port->addr = ioremap(hpa, GSC_STATUS + 4);
365	if (!ps2port->addr) {
366		ret = -ENOMEM;
367		goto fail_nomem;
368	}
369	spin_lock_init(&ps2port->lock);
370
371	gscps2_reset(ps2port);
372	ps2port->id = readb(ps2port->addr + GSC_ID) & 0x0f;
373
374	snprintf(serio->name, sizeof(serio->name), "gsc-ps2-%s",
375		 (ps2port->id == GSC_ID_KEYBOARD) ? "keyboard" : "mouse");
376	strscpy(serio->phys, dev_name(&dev->dev), sizeof(serio->phys));
377	serio->id.type		= SERIO_8042;
378	serio->write		= gscps2_write;
379	serio->open		= gscps2_open;
380	serio->close		= gscps2_close;
381	serio->port_data	= ps2port;
382	serio->dev.parent	= &dev->dev;
383
384	ret = -EBUSY;
385	if (request_irq(dev->irq, gscps2_interrupt, IRQF_SHARED, ps2port->port->name, ps2port))
386		goto fail_miserably;
387
388	if (ps2port->id != GSC_ID_KEYBOARD && ps2port->id != GSC_ID_MOUSE) {
389		printk(KERN_WARNING PFX "Unsupported PS/2 port at 0x%08lx (id=%d) ignored\n",
390				hpa, ps2port->id);
391		ret = -ENODEV;
392		goto fail;
393	}
394
395#if 0
396	if (!request_mem_region(hpa, GSC_STATUS + 4, ps2port->port.name))
397		goto fail;
398#endif
399
400	pr_info("serio: %s port at 0x%08lx irq %d @ %s\n",
401		ps2port->port->name,
402		hpa,
403		ps2port->padev->irq,
404		ps2port->port->phys);
405
406	serio_register_port(ps2port->port);
407
408	list_add_tail(&ps2port->node, &ps2port_list);
409
410	return 0;
411
412fail:
413	free_irq(dev->irq, ps2port);
414
415fail_miserably:
416	iounmap(ps2port->addr);
417	release_mem_region(dev->hpa.start, GSC_STATUS + 4);
418
419fail_nomem:
420	kfree(ps2port);
421	kfree(serio);
422	return ret;
423}
424
425/**
426 * gscps2_remove() - Removes PS2 devices
427 * @dev: pointer to parisc_device which shall be removed
428 *
429 * @return: success/error report
430 */
431
432static void __exit gscps2_remove(struct parisc_device *dev)
433{
434	struct gscps2port *ps2port = dev_get_drvdata(&dev->dev);
435
436	serio_unregister_port(ps2port->port);
437	free_irq(dev->irq, ps2port);
438	gscps2_flush(ps2port);
439	list_del(&ps2port->node);
440	iounmap(ps2port->addr);
441#if 0
442	release_mem_region(dev->hpa, GSC_STATUS + 4);
443#endif
444	dev_set_drvdata(&dev->dev, NULL);
445	kfree(ps2port);
446}
447
448
449static const struct parisc_device_id gscps2_device_tbl[] __initconst = {
450	{ HPHW_FIO, HVERSION_REV_ANY_ID, HVERSION_ANY_ID, 0x00084 }, /* LASI PS/2 */
451#ifdef DINO_TESTED
452	{ HPHW_FIO, HVERSION_REV_ANY_ID, HVERSION_ANY_ID, 0x00096 }, /* DINO PS/2 */
453#endif
454	{ 0, }	/* 0 terminated list */
455};
456MODULE_DEVICE_TABLE(parisc, gscps2_device_tbl);
457
458static struct parisc_driver parisc_ps2_driver __refdata = {
459	.name		= "gsc_ps2",
460	.id_table	= gscps2_device_tbl,
461	.probe		= gscps2_probe,
462	.remove		= __exit_p(gscps2_remove),
463};
464
465static int __init gscps2_init(void)
466{
467	register_parisc_driver(&parisc_ps2_driver);
468	return 0;
469}
470
471static void __exit gscps2_exit(void)
472{
473	unregister_parisc_driver(&parisc_ps2_driver);
474}
475
476
477module_init(gscps2_init);
478module_exit(gscps2_exit);
479