xref: /openbmc/linux/drivers/input/serio/gscps2.c (revision 82e6fdd6) 
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 
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 
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 
84 static irqreturn_t gscps2_interrupt(int irq, void *dev);
85 
86 #define BUFFER_SIZE 0x0f
87 
88 /* GSC PS/2 port device struct */
89 struct gscps2port {
90 	struct list_head node;
91 	struct parisc_device *padev;
92 	struct serio *port;
93 	spinlock_t lock;
94 	char *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 
117 static int wait_TBE(char *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 
133 static 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 
146 static inline int gscps2_writeb_output(struct gscps2port *ps2port, u8 data)
147 {
148 	unsigned long flags;
149 	char *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(ps2port->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 
178 static 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 
201 static void gscps2_reset(struct gscps2port *ps2port)
202 {
203 	char *addr = ps2port->addr;
204 	unsigned long flags;
205 
206 	/* reset the interface */
207 	spin_lock_irqsave(&ps2port->lock, flags);
208 	gscps2_flush(ps2port);
209 	writeb(0xff, addr+GSC_RESET);
210 	gscps2_flush(ps2port);
211 	spin_unlock_irqrestore(&ps2port->lock, flags);
212 }
213 
214 static LIST_HEAD(ps2port_list);
215 
216 /**
217  * gscps2_interrupt() - Interruption service routine
218  *
219  * This function reads received PS/2 bytes and processes them on
220  * all interfaces.
221  * The problematic part here is, that the keyboard and mouse PS/2 port
222  * share the same interrupt and it's not possible to send data if any
223  * one of them holds input data. To solve this problem we try to receive
224  * the data as fast as possible and handle the reporting to the upper layer
225  * later.
226  */
227 
228 static irqreturn_t gscps2_interrupt(int irq, void *dev)
229 {
230 	struct gscps2port *ps2port;
231 
232 	list_for_each_entry(ps2port, &ps2port_list, node) {
233 
234 	  unsigned long flags;
235 	  spin_lock_irqsave(&ps2port->lock, flags);
236 
237 	  while ( (ps2port->buffer[ps2port->append].str =
238 		   gscps2_readb_status(ps2port->addr)) & GSC_STAT_RBNE ) {
239 		ps2port->buffer[ps2port->append].data =
240 				gscps2_readb_input(ps2port->addr);
241 		ps2port->append = ((ps2port->append+1) & BUFFER_SIZE);
242 	  }
243 
244 	  spin_unlock_irqrestore(&ps2port->lock, flags);
245 
246 	} /* list_for_each_entry */
247 
248 	/* all data was read from the ports - now report the data to upper layer */
249 
250 	list_for_each_entry(ps2port, &ps2port_list, node) {
251 
252 	  while (ps2port->act != ps2port->append) {
253 
254 	    unsigned int rxflags;
255 	    u8 data, status;
256 
257 	    /* Did new data arrived while we read existing data ?
258 	       If yes, exit now and let the new irq handler start over again */
259 	    if (gscps2_readb_status(ps2port->addr) & GSC_STAT_CMPINTR)
260 		return IRQ_HANDLED;
261 
262 	    status = ps2port->buffer[ps2port->act].str;
263 	    data   = ps2port->buffer[ps2port->act].data;
264 
265 	    ps2port->act = ((ps2port->act+1) & BUFFER_SIZE);
266 	    rxflags =	((status & GSC_STAT_TERR) ? SERIO_TIMEOUT : 0 ) |
267 			((status & GSC_STAT_PERR) ? SERIO_PARITY  : 0 );
268 
269 	    serio_interrupt(ps2port->port, data, rxflags);
270 
271 	  } /* while() */
272 
273 	} /* list_for_each_entry */
274 
275 	return IRQ_HANDLED;
276 }
277 
278 
279 /*
280  * gscps2_write() - send a byte out through the aux interface.
281  */
282 
283 static int gscps2_write(struct serio *port, unsigned char data)
284 {
285 	struct gscps2port *ps2port = port->port_data;
286 
287 	if (!gscps2_writeb_output(ps2port, data)) {
288 		printk(KERN_DEBUG PFX "sending byte %#x failed.\n", data);
289 		return -1;
290 	}
291 	return 0;
292 }
293 
294 /*
295  * gscps2_open() is called when a port is opened by the higher layer.
296  * It resets and enables the port.
297  */
298 
299 static int gscps2_open(struct serio *port)
300 {
301 	struct gscps2port *ps2port = port->port_data;
302 
303 	gscps2_reset(ps2port);
304 
305 	/* enable it */
306 	gscps2_enable(ps2port, ENABLE);
307 
308 	gscps2_interrupt(0, NULL);
309 
310 	return 0;
311 }
312 
313 /*
314  * gscps2_close() disables the port
315  */
316 
317 static void gscps2_close(struct serio *port)
318 {
319 	struct gscps2port *ps2port = port->port_data;
320 	gscps2_enable(ps2port, DISABLE);
321 }
322 
323 /**
324  * gscps2_probe() - Probes PS2 devices
325  * @return: success/error report
326  */
327 
328 static int __init gscps2_probe(struct parisc_device *dev)
329 {
330 	struct gscps2port *ps2port;
331 	struct serio *serio;
332 	unsigned long hpa = dev->hpa.start;
333 	int ret;
334 
335 	if (!dev->irq)
336 		return -ENODEV;
337 
338 	/* Offset for DINO PS/2. Works with LASI even */
339 	if (dev->id.sversion == 0x96)
340 		hpa += GSC_DINO_OFFSET;
341 
342 	ps2port = kzalloc(sizeof(struct gscps2port), GFP_KERNEL);
343 	serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
344 	if (!ps2port || !serio) {
345 		ret = -ENOMEM;
346 		goto fail_nomem;
347 	}
348 
349 	dev_set_drvdata(&dev->dev, ps2port);
350 
351 	ps2port->port = serio;
352 	ps2port->padev = dev;
353 	ps2port->addr = ioremap_nocache(hpa, GSC_STATUS + 4);
354 	spin_lock_init(&ps2port->lock);
355 
356 	gscps2_reset(ps2port);
357 	ps2port->id = readb(ps2port->addr + GSC_ID) & 0x0f;
358 
359 	snprintf(serio->name, sizeof(serio->name), "gsc-ps2-%s",
360 		 (ps2port->id == GSC_ID_KEYBOARD) ? "keyboard" : "mouse");
361 	strlcpy(serio->phys, dev_name(&dev->dev), sizeof(serio->phys));
362 	serio->id.type		= SERIO_8042;
363 	serio->write		= gscps2_write;
364 	serio->open		= gscps2_open;
365 	serio->close		= gscps2_close;
366 	serio->port_data	= ps2port;
367 	serio->dev.parent	= &dev->dev;
368 
369 	ret = -EBUSY;
370 	if (request_irq(dev->irq, gscps2_interrupt, IRQF_SHARED, ps2port->port->name, ps2port))
371 		goto fail_miserably;
372 
373 	if (ps2port->id != GSC_ID_KEYBOARD && ps2port->id != GSC_ID_MOUSE) {
374 		printk(KERN_WARNING PFX "Unsupported PS/2 port at 0x%08lx (id=%d) ignored\n",
375 				hpa, ps2port->id);
376 		ret = -ENODEV;
377 		goto fail;
378 	}
379 
380 #if 0
381 	if (!request_mem_region(hpa, GSC_STATUS + 4, ps2port->port.name))
382 		goto fail;
383 #endif
384 
385 	printk(KERN_INFO "serio: %s port at 0x%p irq %d @ %s\n",
386 		ps2port->port->name,
387 		ps2port->addr,
388 		ps2port->padev->irq,
389 		ps2port->port->phys);
390 
391 	serio_register_port(ps2port->port);
392 
393 	list_add_tail(&ps2port->node, &ps2port_list);
394 
395 	return 0;
396 
397 fail:
398 	free_irq(dev->irq, ps2port);
399 
400 fail_miserably:
401 	iounmap(ps2port->addr);
402 	release_mem_region(dev->hpa.start, GSC_STATUS + 4);
403 
404 fail_nomem:
405 	kfree(ps2port);
406 	kfree(serio);
407 	return ret;
408 }
409 
410 /**
411  * gscps2_remove() - Removes PS2 devices
412  * @return: success/error report
413  */
414 
415 static int __exit gscps2_remove(struct parisc_device *dev)
416 {
417 	struct gscps2port *ps2port = dev_get_drvdata(&dev->dev);
418 
419 	serio_unregister_port(ps2port->port);
420 	free_irq(dev->irq, ps2port);
421 	gscps2_flush(ps2port);
422 	list_del(&ps2port->node);
423 	iounmap(ps2port->addr);
424 #if 0
425 	release_mem_region(dev->hpa, GSC_STATUS + 4);
426 #endif
427 	dev_set_drvdata(&dev->dev, NULL);
428 	kfree(ps2port);
429 	return 0;
430 }
431 
432 
433 static const struct parisc_device_id gscps2_device_tbl[] __initconst = {
434 	{ HPHW_FIO, HVERSION_REV_ANY_ID, HVERSION_ANY_ID, 0x00084 }, /* LASI PS/2 */
435 #ifdef DINO_TESTED
436 	{ HPHW_FIO, HVERSION_REV_ANY_ID, HVERSION_ANY_ID, 0x00096 }, /* DINO PS/2 */
437 #endif
438 	{ 0, }	/* 0 terminated list */
439 };
440 MODULE_DEVICE_TABLE(parisc, gscps2_device_tbl);
441 
442 static struct parisc_driver parisc_ps2_driver __refdata = {
443 	.name		= "gsc_ps2",
444 	.id_table	= gscps2_device_tbl,
445 	.probe		= gscps2_probe,
446 	.remove		= __exit_p(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