xref: /openbmc/linux/drivers/input/serio/gscps2.c (revision 43ffe817) 
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 __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 
117 static 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 
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 __iomem *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(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 	unsigned long flags;
204 
205 	/* reset the interface */
206 	spin_lock_irqsave(&ps2port->lock, flags);
207 	gscps2_flush(ps2port);
208 	writeb(0xff, ps2port->addr + GSC_RESET);
209 	gscps2_flush(ps2port);
210 	spin_unlock_irqrestore(&ps2port->lock, flags);
211 }
212 
213 static LIST_HEAD(ps2port_list);
214 
215 /**
216  * gscps2_interrupt() - Interruption service routine
217  *
218  * This function reads received PS/2 bytes and processes them on
219  * all interfaces.
220  * The problematic part here is, that the keyboard and mouse PS/2 port
221  * share the same interrupt and it's not possible to send data if any
222  * one of them holds input data. To solve this problem we try to receive
223  * the data as fast as possible and handle the reporting to the upper layer
224  * later.
225  */
226 
227 static irqreturn_t gscps2_interrupt(int irq, void *dev)
228 {
229 	struct gscps2port *ps2port;
230 
231 	list_for_each_entry(ps2port, &ps2port_list, node) {
232 
233 	  unsigned long flags;
234 	  spin_lock_irqsave(&ps2port->lock, flags);
235 
236 	  while ( (ps2port->buffer[ps2port->append].str =
237 		   gscps2_readb_status(ps2port->addr)) & GSC_STAT_RBNE ) {
238 		ps2port->buffer[ps2port->append].data =
239 				gscps2_readb_input(ps2port->addr);
240 		ps2port->append = ((ps2port->append+1) & BUFFER_SIZE);
241 	  }
242 
243 	  spin_unlock_irqrestore(&ps2port->lock, flags);
244 
245 	} /* list_for_each_entry */
246 
247 	/* all data was read from the ports - now report the data to upper layer */
248 
249 	list_for_each_entry(ps2port, &ps2port_list, node) {
250 
251 	  while (ps2port->act != ps2port->append) {
252 
253 	    unsigned int rxflags;
254 	    u8 data, status;
255 
256 	    /* Did new data arrived while we read existing data ?
257 	       If yes, exit now and let the new irq handler start over again */
258 	    if (gscps2_readb_status(ps2port->addr) & GSC_STAT_CMPINTR)
259 		return IRQ_HANDLED;
260 
261 	    status = ps2port->buffer[ps2port->act].str;
262 	    data   = ps2port->buffer[ps2port->act].data;
263 
264 	    ps2port->act = ((ps2port->act+1) & BUFFER_SIZE);
265 	    rxflags =	((status & GSC_STAT_TERR) ? SERIO_TIMEOUT : 0 ) |
266 			((status & GSC_STAT_PERR) ? SERIO_PARITY  : 0 );
267 
268 	    serio_interrupt(ps2port->port, data, rxflags);
269 
270 	  } /* while() */
271 
272 	} /* list_for_each_entry */
273 
274 	return IRQ_HANDLED;
275 }
276 
277 
278 /*
279  * gscps2_write() - send a byte out through the aux interface.
280  */
281 
282 static int gscps2_write(struct serio *port, unsigned char data)
283 {
284 	struct gscps2port *ps2port = port->port_data;
285 
286 	if (!gscps2_writeb_output(ps2port, data)) {
287 		printk(KERN_DEBUG PFX "sending byte %#x failed.\n", data);
288 		return -1;
289 	}
290 	return 0;
291 }
292 
293 /*
294  * gscps2_open() is called when a port is opened by the higher layer.
295  * It resets and enables the port.
296  */
297 
298 static int gscps2_open(struct serio *port)
299 {
300 	struct gscps2port *ps2port = port->port_data;
301 
302 	gscps2_reset(ps2port);
303 
304 	/* enable it */
305 	gscps2_enable(ps2port, ENABLE);
306 
307 	gscps2_interrupt(0, NULL);
308 
309 	return 0;
310 }
311 
312 /*
313  * gscps2_close() disables the port
314  */
315 
316 static void gscps2_close(struct serio *port)
317 {
318 	struct gscps2port *ps2port = port->port_data;
319 	gscps2_enable(ps2port, DISABLE);
320 }
321 
322 /**
323  * gscps2_probe() - Probes PS2 devices
324  * @return: success/error report
325  */
326 
327 static int __init gscps2_probe(struct parisc_device *dev)
328 {
329 	struct gscps2port *ps2port;
330 	struct serio *serio;
331 	unsigned long hpa = dev->hpa.start;
332 	int ret;
333 
334 	if (!dev->irq)
335 		return -ENODEV;
336 
337 	/* Offset for DINO PS/2. Works with LASI even */
338 	if (dev->id.sversion == 0x96)
339 		hpa += GSC_DINO_OFFSET;
340 
341 	ps2port = kzalloc(sizeof(struct gscps2port), GFP_KERNEL);
342 	serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
343 	if (!ps2port || !serio) {
344 		ret = -ENOMEM;
345 		goto fail_nomem;
346 	}
347 
348 	dev_set_drvdata(&dev->dev, ps2port);
349 
350 	ps2port->port = serio;
351 	ps2port->padev = dev;
352 	ps2port->addr = ioremap(hpa, GSC_STATUS + 4);
353 	spin_lock_init(&ps2port->lock);
354 
355 	gscps2_reset(ps2port);
356 	ps2port->id = readb(ps2port->addr + GSC_ID) & 0x0f;
357 
358 	snprintf(serio->name, sizeof(serio->name), "gsc-ps2-%s",
359 		 (ps2port->id == GSC_ID_KEYBOARD) ? "keyboard" : "mouse");
360 	strlcpy(serio->phys, dev_name(&dev->dev), sizeof(serio->phys));
361 	serio->id.type		= SERIO_8042;
362 	serio->write		= gscps2_write;
363 	serio->open		= gscps2_open;
364 	serio->close		= gscps2_close;
365 	serio->port_data	= ps2port;
366 	serio->dev.parent	= &dev->dev;
367 
368 	ret = -EBUSY;
369 	if (request_irq(dev->irq, gscps2_interrupt, IRQF_SHARED, ps2port->port->name, ps2port))
370 		goto fail_miserably;
371 
372 	if (ps2port->id != GSC_ID_KEYBOARD && ps2port->id != GSC_ID_MOUSE) {
373 		printk(KERN_WARNING PFX "Unsupported PS/2 port at 0x%08lx (id=%d) ignored\n",
374 				hpa, ps2port->id);
375 		ret = -ENODEV;
376 		goto fail;
377 	}
378 
379 #if 0
380 	if (!request_mem_region(hpa, GSC_STATUS + 4, ps2port->port.name))
381 		goto fail;
382 #endif
383 
384 	pr_info("serio: %s port at 0x%08lx irq %d @ %s\n",
385 		ps2port->port->name,
386 		hpa,
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 
396 fail:
397 	free_irq(dev->irq, ps2port);
398 
399 fail_miserably:
400 	iounmap(ps2port->addr);
401 	release_mem_region(dev->hpa.start, GSC_STATUS + 4);
402 
403 fail_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 
414 static int __exit 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 #if 0
424 	release_mem_region(dev->hpa, GSC_STATUS + 4);
425 #endif
426 	dev_set_drvdata(&dev->dev, NULL);
427 	kfree(ps2port);
428 	return 0;
429 }
430 
431 
432 static const struct parisc_device_id gscps2_device_tbl[] __initconst = {
433 	{ HPHW_FIO, HVERSION_REV_ANY_ID, HVERSION_ANY_ID, 0x00084 }, /* LASI PS/2 */
434 #ifdef DINO_TESTED
435 	{ HPHW_FIO, HVERSION_REV_ANY_ID, HVERSION_ANY_ID, 0x00096 }, /* DINO PS/2 */
436 #endif
437 	{ 0, }	/* 0 terminated list */
438 };
439 MODULE_DEVICE_TABLE(parisc, gscps2_device_tbl);
440 
441 static struct parisc_driver parisc_ps2_driver __refdata = {
442 	.name		= "gsc_ps2",
443 	.id_table	= gscps2_device_tbl,
444 	.probe		= gscps2_probe,
445 	.remove		= __exit_p(gscps2_remove),
446 };
447 
448 static int __init gscps2_init(void)
449 {
450 	register_parisc_driver(&parisc_ps2_driver);
451 	return 0;
452 }
453 
454 static void __exit gscps2_exit(void)
455 {
456 	unregister_parisc_driver(&parisc_ps2_driver);
457 }
458 
459 
460 module_init(gscps2_init);
461 module_exit(gscps2_exit);
462 
463