xref: /openbmc/linux/drivers/input/serio/gscps2.c (revision b627b4ed) 
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 
39 MODULE_AUTHOR("Laurent Canet <canetl@esiee.fr>, Thibaut Varene <varenet@parisc-linux.org>, Helge Deller <deller@gmx.de>");
40 MODULE_DESCRIPTION("HP GSC PS2 port driver");
41 MODULE_LICENSE("GPL");
42 MODULE_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 
85 static irqreturn_t gscps2_interrupt(int irq, void *dev);
86 
87 #define BUFFER_SIZE 0x0f
88 
89 /* GSC PS/2 port device struct */
90 struct 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 
118 static 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 
134 static 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 success, 0 on error
145  */
146 
147 static 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 
179 static 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 
202 static 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 
215 static 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 
229 static 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 
284 static 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 
300 static 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 
318 static 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 
329 static 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 = kzalloc(sizeof(struct gscps2port), GFP_KERNEL);
344 	serio = kzalloc(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 	ps2port->port = serio;
353 	ps2port->padev = dev;
354 	ps2port->addr = ioremap_nocache(hpa, GSC_STATUS + 4);
355 	spin_lock_init(&ps2port->lock);
356 
357 	gscps2_reset(ps2port);
358 	ps2port->id = readb(ps2port->addr + GSC_ID) & 0x0f;
359 
360 	snprintf(serio->name, sizeof(serio->name), "GSC PS/2 %s",
361 		 (ps2port->id == GSC_ID_KEYBOARD) ? "keyboard" : "mouse");
362 	strlcpy(serio->phys, dev_name(&dev->dev), sizeof(serio->phys));
363 	serio->id.type		= SERIO_8042;
364 	serio->write		= gscps2_write;
365 	serio->open		= gscps2_open;
366 	serio->close		= gscps2_close;
367 	serio->port_data	= ps2port;
368 	serio->dev.parent	= &dev->dev;
369 
370 	ret = -EBUSY;
371 	if (request_irq(dev->irq, gscps2_interrupt, IRQF_SHARED, ps2port->port->name, ps2port))
372 		goto fail_miserably;
373 
374 	if (ps2port->id != GSC_ID_KEYBOARD && ps2port->id != GSC_ID_MOUSE) {
375 		printk(KERN_WARNING PFX "Unsupported PS/2 port at 0x%08lx (id=%d) ignored\n",
376 				hpa, ps2port->id);
377 		ret = -ENODEV;
378 		goto fail;
379 	}
380 
381 #if 0
382 	if (!request_mem_region(hpa, GSC_STATUS + 4, ps2port->port.name))
383 		goto fail;
384 #endif
385 
386 	printk(KERN_INFO "serio: %s port at 0x%p irq %d @ %s\n",
387 		ps2port->port->name,
388 		ps2port->addr,
389 		ps2port->padev->irq,
390 		ps2port->port->phys);
391 
392 	serio_register_port(ps2port->port);
393 
394 	list_add_tail(&ps2port->node, &ps2port_list);
395 
396 	return 0;
397 
398 fail:
399 	free_irq(dev->irq, ps2port);
400 
401 fail_miserably:
402 	iounmap(ps2port->addr);
403 	release_mem_region(dev->hpa.start, GSC_STATUS + 4);
404 
405 fail_nomem:
406 	kfree(ps2port);
407 	kfree(serio);
408 	return ret;
409 }
410 
411 /**
412  * gscps2_remove() - Removes PS2 devices
413  * @return: success/error report
414  */
415 
416 static int __devexit gscps2_remove(struct parisc_device *dev)
417 {
418 	struct gscps2port *ps2port = dev_get_drvdata(&dev->dev);
419 
420 	serio_unregister_port(ps2port->port);
421 	free_irq(dev->irq, ps2port);
422 	gscps2_flush(ps2port);
423 	list_del(&ps2port->node);
424 	iounmap(ps2port->addr);
425 #if 0
426 	release_mem_region(dev->hpa, GSC_STATUS + 4);
427 #endif
428 	dev_set_drvdata(&dev->dev, NULL);
429 	kfree(ps2port);
430 	return 0;
431 }
432 
433 
434 static struct parisc_device_id gscps2_device_tbl[] = {
435 	{ HPHW_FIO, HVERSION_REV_ANY_ID, HVERSION_ANY_ID, 0x00084 }, /* LASI PS/2 */
436 #ifdef DINO_TESTED
437 	{ HPHW_FIO, HVERSION_REV_ANY_ID, HVERSION_ANY_ID, 0x00096 }, /* DINO PS/2 */
438 #endif
439 	{ 0, }	/* 0 terminated list */
440 };
441 
442 static 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 
449 static int __init gscps2_init(void)
450 {
451 	register_parisc_driver(&parisc_ps2_driver);
452 	return 0;
453 }
454 
455 static void __exit gscps2_exit(void)
456 {
457 	unregister_parisc_driver(&parisc_ps2_driver);
458 }
459 
460 
461 module_init(gscps2_init);
462 module_exit(gscps2_exit);
463 
464