xref: /openbmc/linux/drivers/input/serio/gscps2.c (revision 31b90347) 
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 #include <linux/pci_ids.h>
35 
36 #include <asm/irq.h>
37 #include <asm/io.h>
38 #include <asm/parisc-device.h>
39 
40 MODULE_AUTHOR("Laurent Canet <canetl@esiee.fr>, Thibaut Varene <varenet@parisc-linux.org>, Helge Deller <deller@gmx.de>");
41 MODULE_DESCRIPTION("HP GSC PS2 port driver");
42 MODULE_LICENSE("GPL");
43 MODULE_DEVICE_TABLE(parisc, gscps2_device_tbl);
44 
45 #define PFX "gscps2.c: "
46 
47 /*
48  * Driver constants
49  */
50 
51 /* various constants */
52 #define ENABLE			1
53 #define DISABLE			0
54 
55 #define GSC_DINO_OFFSET		0x0800	/* offset for DINO controller versus LASI one */
56 
57 /* PS/2 IO port offsets */
58 #define GSC_ID			0x00	/* device ID offset (see: GSC_ID_XXX) */
59 #define GSC_RESET		0x00	/* reset port offset */
60 #define GSC_RCVDATA		0x04	/* receive port offset */
61 #define GSC_XMTDATA		0x04	/* transmit port offset */
62 #define GSC_CONTROL		0x08	/* see: Control register bits */
63 #define GSC_STATUS		0x0C	/* see: Status register bits */
64 
65 /* Control register bits */
66 #define GSC_CTRL_ENBL		0x01	/* enable interface */
67 #define GSC_CTRL_LPBXR		0x02	/* loopback operation */
68 #define GSC_CTRL_DIAG		0x20	/* directly control clock/data line */
69 #define GSC_CTRL_DATDIR		0x40	/* data line direct control */
70 #define GSC_CTRL_CLKDIR		0x80	/* clock line direct control */
71 
72 /* Status register bits */
73 #define GSC_STAT_RBNE		0x01	/* Receive Buffer Not Empty */
74 #define GSC_STAT_TBNE		0x02	/* Transmit Buffer Not Empty */
75 #define GSC_STAT_TERR		0x04	/* Timeout Error */
76 #define GSC_STAT_PERR		0x08	/* Parity Error */
77 #define GSC_STAT_CMPINTR	0x10	/* Composite Interrupt = irq on any port */
78 #define GSC_STAT_DATSHD		0x40	/* Data Line Shadow */
79 #define GSC_STAT_CLKSHD		0x80	/* Clock Line Shadow */
80 
81 /* IDs returned by GSC_ID port register */
82 #define GSC_ID_KEYBOARD		0	/* device ID values */
83 #define GSC_ID_MOUSE		1
84 
85 
86 static irqreturn_t gscps2_interrupt(int irq, void *dev);
87 
88 #define BUFFER_SIZE 0x0f
89 
90 /* GSC PS/2 port device struct */
91 struct gscps2port {
92 	struct list_head node;
93 	struct parisc_device *padev;
94 	struct serio *port;
95 	spinlock_t lock;
96 	char *addr;
97 	u8 act, append; /* position in buffer[] */
98 	struct {
99 		u8 data;
100 		u8 str;
101 	} buffer[BUFFER_SIZE+1];
102 	int id;
103 };
104 
105 /*
106  * Various HW level routines
107  */
108 
109 #define gscps2_readb_input(x)		readb((x)+GSC_RCVDATA)
110 #define gscps2_readb_control(x)		readb((x)+GSC_CONTROL)
111 #define gscps2_readb_status(x)		readb((x)+GSC_STATUS)
112 #define gscps2_writeb_control(x, y)	writeb((x), (y)+GSC_CONTROL)
113 
114 
115 /*
116  * wait_TBE() - wait for Transmit Buffer Empty
117  */
118 
119 static int wait_TBE(char *addr)
120 {
121 	int timeout = 25000; /* device is expected to react within 250 msec */
122 	while (gscps2_readb_status(addr) & GSC_STAT_TBNE) {
123 		if (!--timeout)
124 			return 0;	/* This should not happen */
125 		udelay(10);
126 	}
127 	return 1;
128 }
129 
130 
131 /*
132  * gscps2_flush() - flush the receive buffer
133  */
134 
135 static void gscps2_flush(struct gscps2port *ps2port)
136 {
137 	while (gscps2_readb_status(ps2port->addr) & GSC_STAT_RBNE)
138 		gscps2_readb_input(ps2port->addr);
139 	ps2port->act = ps2port->append = 0;
140 }
141 
142 /*
143  * gscps2_writeb_output() - write a byte to the port
144  *
145  * returns 1 on success, 0 on error
146  */
147 
148 static inline int gscps2_writeb_output(struct gscps2port *ps2port, u8 data)
149 {
150 	unsigned long flags;
151 	char *addr = ps2port->addr;
152 
153 	if (!wait_TBE(addr)) {
154 		printk(KERN_DEBUG PFX "timeout - could not write byte %#x\n", data);
155 		return 0;
156 	}
157 
158 	while (gscps2_readb_status(ps2port->addr) & GSC_STAT_RBNE)
159 		/* wait */;
160 
161 	spin_lock_irqsave(&ps2port->lock, flags);
162 	writeb(data, addr+GSC_XMTDATA);
163 	spin_unlock_irqrestore(&ps2port->lock, flags);
164 
165 	/* this is ugly, but due to timing of the port it seems to be necessary. */
166 	mdelay(6);
167 
168 	/* make sure any received data is returned as fast as possible */
169 	/* this is important e.g. when we set the LEDs on the keyboard */
170 	gscps2_interrupt(0, NULL);
171 
172 	return 1;
173 }
174 
175 
176 /*
177  * gscps2_enable() - enables or disables the port
178  */
179 
180 static void gscps2_enable(struct gscps2port *ps2port, int enable)
181 {
182 	unsigned long flags;
183 	u8 data;
184 
185 	/* now enable/disable the port */
186 	spin_lock_irqsave(&ps2port->lock, flags);
187 	gscps2_flush(ps2port);
188 	data = gscps2_readb_control(ps2port->addr);
189 	if (enable)
190 		data |= GSC_CTRL_ENBL;
191 	else
192 		data &= ~GSC_CTRL_ENBL;
193 	gscps2_writeb_control(data, ps2port->addr);
194 	spin_unlock_irqrestore(&ps2port->lock, flags);
195 	wait_TBE(ps2port->addr);
196 	gscps2_flush(ps2port);
197 }
198 
199 /*
200  * gscps2_reset() - resets the PS/2 port
201  */
202 
203 static void gscps2_reset(struct gscps2port *ps2port)
204 {
205 	char *addr = ps2port->addr;
206 	unsigned long flags;
207 
208 	/* reset the interface */
209 	spin_lock_irqsave(&ps2port->lock, flags);
210 	gscps2_flush(ps2port);
211 	writeb(0xff, addr+GSC_RESET);
212 	gscps2_flush(ps2port);
213 	spin_unlock_irqrestore(&ps2port->lock, flags);
214 }
215 
216 static LIST_HEAD(ps2port_list);
217 
218 /**
219  * gscps2_interrupt() - Interruption service routine
220  *
221  * This function reads received PS/2 bytes and processes them on
222  * all interfaces.
223  * The problematic part here is, that the keyboard and mouse PS/2 port
224  * share the same interrupt and it's not possible to send data if any
225  * one of them holds input data. To solve this problem we try to receive
226  * the data as fast as possible and handle the reporting to the upper layer
227  * later.
228  */
229 
230 static irqreturn_t gscps2_interrupt(int irq, void *dev)
231 {
232 	struct gscps2port *ps2port;
233 
234 	list_for_each_entry(ps2port, &ps2port_list, node) {
235 
236 	  unsigned long flags;
237 	  spin_lock_irqsave(&ps2port->lock, flags);
238 
239 	  while ( (ps2port->buffer[ps2port->append].str =
240 		   gscps2_readb_status(ps2port->addr)) & GSC_STAT_RBNE ) {
241 		ps2port->buffer[ps2port->append].data =
242 				gscps2_readb_input(ps2port->addr);
243 		ps2port->append = ((ps2port->append+1) & BUFFER_SIZE);
244 	  }
245 
246 	  spin_unlock_irqrestore(&ps2port->lock, flags);
247 
248 	} /* list_for_each_entry */
249 
250 	/* all data was read from the ports - now report the data to upper layer */
251 
252 	list_for_each_entry(ps2port, &ps2port_list, node) {
253 
254 	  while (ps2port->act != ps2port->append) {
255 
256 	    unsigned int rxflags;
257 	    u8 data, status;
258 
259 	    /* Did new data arrived while we read existing data ?
260 	       If yes, exit now and let the new irq handler start over again */
261 	    if (gscps2_readb_status(ps2port->addr) & GSC_STAT_CMPINTR)
262 		return IRQ_HANDLED;
263 
264 	    status = ps2port->buffer[ps2port->act].str;
265 	    data   = ps2port->buffer[ps2port->act].data;
266 
267 	    ps2port->act = ((ps2port->act+1) & BUFFER_SIZE);
268 	    rxflags =	((status & GSC_STAT_TERR) ? SERIO_TIMEOUT : 0 ) |
269 			((status & GSC_STAT_PERR) ? SERIO_PARITY  : 0 );
270 
271 	    serio_interrupt(ps2port->port, data, rxflags);
272 
273 	  } /* while() */
274 
275 	} /* list_for_each_entry */
276 
277 	return IRQ_HANDLED;
278 }
279 
280 
281 /*
282  * gscps2_write() - send a byte out through the aux interface.
283  */
284 
285 static int gscps2_write(struct serio *port, unsigned char data)
286 {
287 	struct gscps2port *ps2port = port->port_data;
288 
289 	if (!gscps2_writeb_output(ps2port, data)) {
290 		printk(KERN_DEBUG PFX "sending byte %#x failed.\n", data);
291 		return -1;
292 	}
293 	return 0;
294 }
295 
296 /*
297  * gscps2_open() is called when a port is opened by the higher layer.
298  * It resets and enables the port.
299  */
300 
301 static int gscps2_open(struct serio *port)
302 {
303 	struct gscps2port *ps2port = port->port_data;
304 
305 	gscps2_reset(ps2port);
306 
307 	/* enable it */
308 	gscps2_enable(ps2port, ENABLE);
309 
310 	gscps2_interrupt(0, NULL);
311 
312 	return 0;
313 }
314 
315 /*
316  * gscps2_close() disables the port
317  */
318 
319 static void gscps2_close(struct serio *port)
320 {
321 	struct gscps2port *ps2port = port->port_data;
322 	gscps2_enable(ps2port, DISABLE);
323 }
324 
325 /**
326  * gscps2_probe() - Probes PS2 devices
327  * @return: success/error report
328  */
329 
330 static int gscps2_probe(struct parisc_device *dev)
331 {
332 	struct gscps2port *ps2port;
333 	struct serio *serio;
334 	unsigned long hpa = dev->hpa.start;
335 	int ret;
336 
337 	if (!dev->irq)
338 		return -ENODEV;
339 
340 	/* Offset for DINO PS/2. Works with LASI even */
341 	if (dev->id.sversion == 0x96)
342 		hpa += GSC_DINO_OFFSET;
343 
344 	ps2port = kzalloc(sizeof(struct gscps2port), GFP_KERNEL);
345 	serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
346 	if (!ps2port || !serio) {
347 		ret = -ENOMEM;
348 		goto fail_nomem;
349 	}
350 
351 	dev_set_drvdata(&dev->dev, ps2port);
352 
353 	ps2port->port = serio;
354 	ps2port->padev = dev;
355 	ps2port->addr = ioremap_nocache(hpa, GSC_STATUS + 4);
356 	spin_lock_init(&ps2port->lock);
357 
358 	gscps2_reset(ps2port);
359 	ps2port->id = readb(ps2port->addr + GSC_ID) & 0x0f;
360 
361 	snprintf(serio->name, sizeof(serio->name), "gsc-ps2-%s",
362 		 (ps2port->id == GSC_ID_KEYBOARD) ? "keyboard" : "mouse");
363 	strlcpy(serio->phys, dev_name(&dev->dev), sizeof(serio->phys));
364 	serio->id.type		= SERIO_8042;
365 	serio->write		= gscps2_write;
366 	serio->open		= gscps2_open;
367 	serio->close		= gscps2_close;
368 	serio->port_data	= ps2port;
369 	serio->dev.parent	= &dev->dev;
370 
371 	ret = -EBUSY;
372 	if (request_irq(dev->irq, gscps2_interrupt, IRQF_SHARED, ps2port->port->name, ps2port))
373 		goto fail_miserably;
374 
375 	if (ps2port->id != GSC_ID_KEYBOARD && ps2port->id != GSC_ID_MOUSE) {
376 		printk(KERN_WARNING PFX "Unsupported PS/2 port at 0x%08lx (id=%d) ignored\n",
377 				hpa, ps2port->id);
378 		ret = -ENODEV;
379 		goto fail;
380 	}
381 
382 #if 0
383 	if (!request_mem_region(hpa, GSC_STATUS + 4, ps2port->port.name))
384 		goto fail;
385 #endif
386 
387 	printk(KERN_INFO "serio: %s port at 0x%p irq %d @ %s\n",
388 		ps2port->port->name,
389 		ps2port->addr,
390 		ps2port->padev->irq,
391 		ps2port->port->phys);
392 
393 	serio_register_port(ps2port->port);
394 
395 	list_add_tail(&ps2port->node, &ps2port_list);
396 
397 	return 0;
398 
399 fail:
400 	free_irq(dev->irq, ps2port);
401 
402 fail_miserably:
403 	iounmap(ps2port->addr);
404 	release_mem_region(dev->hpa.start, GSC_STATUS + 4);
405 
406 fail_nomem:
407 	kfree(ps2port);
408 	kfree(serio);
409 	return ret;
410 }
411 
412 /**
413  * gscps2_remove() - Removes PS2 devices
414  * @return: success/error report
415  */
416 
417 static int gscps2_remove(struct parisc_device *dev)
418 {
419 	struct gscps2port *ps2port = dev_get_drvdata(&dev->dev);
420 
421 	serio_unregister_port(ps2port->port);
422 	free_irq(dev->irq, ps2port);
423 	gscps2_flush(ps2port);
424 	list_del(&ps2port->node);
425 	iounmap(ps2port->addr);
426 #if 0
427 	release_mem_region(dev->hpa, GSC_STATUS + 4);
428 #endif
429 	dev_set_drvdata(&dev->dev, NULL);
430 	kfree(ps2port);
431 	return 0;
432 }
433 
434 
435 static struct parisc_device_id gscps2_device_tbl[] = {
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 };
442 
443 static struct parisc_driver parisc_ps2_driver = {
444 	.name		= "gsc_ps2",
445 	.id_table	= gscps2_device_tbl,
446 	.probe		= gscps2_probe,
447 	.remove		= gscps2_remove,
448 };
449 
450 static int __init gscps2_init(void)
451 {
452 	register_parisc_driver(&parisc_ps2_driver);
453 	return 0;
454 }
455 
456 static void __exit gscps2_exit(void)
457 {
458 	unregister_parisc_driver(&parisc_ps2_driver);
459 }
460 
461 
462 module_init(gscps2_init);
463 module_exit(gscps2_exit);
464 
465