xref: /linux/drivers/input/serio/gscps2.c (revision 7d8d6ad659c02ed5d2387777194c22e8e81dbb2b) 
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 	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 
176 static 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 
199 static 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 
208 static LIST_HEAD(ps2port_list);
209 
210 static 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 		ps2port->append = (ps2port->append + 1) & BUFFER_SIZE;
223 	} while (true);
224 }
225 
226 static bool gscps2_report_data(struct gscps2port *ps2port)
227 {
228 	unsigned int rxflags;
229 	u8 data, status;
230 
231 	while (ps2port->act != ps2port->append) {
232 		/*
233 		 * Did new data arrived while we read existing data ?
234 		 * If yes, exit now and let the new irq handler start
235 		 * over again.
236 		 */
237 		if (gscps2_readb_status(ps2port->addr) & GSC_STAT_CMPINTR)
238 			return true;
239 
240 		status = ps2port->buffer[ps2port->act].str;
241 		data   = ps2port->buffer[ps2port->act].data;
242 
243 		ps2port->act = (ps2port->act + 1) & BUFFER_SIZE;
244 		rxflags = ((status & GSC_STAT_TERR) ? SERIO_TIMEOUT : 0 ) |
245 			  ((status & GSC_STAT_PERR) ? SERIO_PARITY  : 0 );
246 
247 		serio_interrupt(ps2port->port, data, rxflags);
248 	}
249 
250 	return false;
251 }
252 
253 /**
254  * gscps2_interrupt() - Interruption service routine
255  * @irq: interrupt number which triggered (unused)
256  * @dev: device pointer (unused)
257  *
258  * This function reads received PS/2 bytes and processes them on
259  * all interfaces.
260  * The problematic part here is, that the keyboard and mouse PS/2 port
261  * share the same interrupt and it's not possible to send data if any
262  * one of them holds input data. To solve this problem we try to receive
263  * the data as fast as possible and handle the reporting to the upper layer
264  * later.
265  */
266 
267 static irqreturn_t gscps2_interrupt(int irq, void *dev)
268 {
269 	struct gscps2port *ps2port;
270 
271 	list_for_each_entry(ps2port, &ps2port_list, node) {
272 		guard(spinlock_irqsave)(&ps2port->lock);
273 
274 		gscps2_read_data(ps2port);
275 	} /* list_for_each_entry */
276 
277 	/* all data was read from the ports - now report the data to upper layer */
278 	list_for_each_entry(ps2port, &ps2port_list, node) {
279 		if (gscps2_report_data(ps2port)) {
280 			/* More data ready - break early to restart interrupt */
281 			break;
282 		}
283 	}
284 
285 	return IRQ_HANDLED;
286 }
287 
288 
289 /*
290  * gscps2_write() - send a byte out through the aux interface.
291  */
292 
293 static int gscps2_write(struct serio *port, unsigned char data)
294 {
295 	struct gscps2port *ps2port = port->port_data;
296 
297 	if (!gscps2_writeb_output(ps2port, data)) {
298 		printk(KERN_DEBUG PFX "sending byte %#x failed.\n", data);
299 		return -1;
300 	}
301 	return 0;
302 }
303 
304 /*
305  * gscps2_open() is called when a port is opened by the higher layer.
306  * It resets and enables the port.
307  */
308 
309 static int gscps2_open(struct serio *port)
310 {
311 	struct gscps2port *ps2port = port->port_data;
312 
313 	gscps2_reset(ps2port);
314 
315 	/* enable it */
316 	gscps2_enable(ps2port, ENABLE);
317 
318 	gscps2_interrupt(0, NULL);
319 
320 	return 0;
321 }
322 
323 /*
324  * gscps2_close() disables the port
325  */
326 
327 static void gscps2_close(struct serio *port)
328 {
329 	struct gscps2port *ps2port = port->port_data;
330 	gscps2_enable(ps2port, DISABLE);
331 }
332 
333 /**
334  * gscps2_probe() - Probes PS2 devices
335  * @dev: pointer to parisc_device struct which will be probed
336  *
337  * @return: success/error report
338  */
339 
340 static int __init gscps2_probe(struct parisc_device *dev)
341 {
342 	struct gscps2port *ps2port;
343 	struct serio *serio;
344 	unsigned long hpa = dev->hpa.start;
345 	int ret;
346 
347 	if (!dev->irq)
348 		return -ENODEV;
349 
350 	/* Offset for DINO PS/2. Works with LASI even */
351 	if (dev->id.sversion == 0x96)
352 		hpa += GSC_DINO_OFFSET;
353 
354 	ps2port = kzalloc_obj(*ps2port);
355 	serio = kzalloc_obj(*serio);
356 	if (!ps2port || !serio) {
357 		ret = -ENOMEM;
358 		goto fail_nomem;
359 	}
360 
361 	dev_set_drvdata(&dev->dev, ps2port);
362 
363 	ps2port->port = serio;
364 	ps2port->padev = dev;
365 	ps2port->addr = ioremap(hpa, GSC_STATUS + 4);
366 	if (!ps2port->addr) {
367 		ret = -ENOMEM;
368 		goto fail_nomem;
369 	}
370 	spin_lock_init(&ps2port->lock);
371 
372 	gscps2_reset(ps2port);
373 	ps2port->id = readb(ps2port->addr + GSC_ID) & 0x0f;
374 
375 	snprintf(serio->name, sizeof(serio->name), "gsc-ps2-%s",
376 		 (ps2port->id == GSC_ID_KEYBOARD) ? "keyboard" : "mouse");
377 	strscpy(serio->phys, dev_name(&dev->dev), sizeof(serio->phys));
378 	serio->id.type		= SERIO_8042;
379 	serio->write		= gscps2_write;
380 	serio->open		= gscps2_open;
381 	serio->close		= gscps2_close;
382 	serio->port_data	= ps2port;
383 	serio->dev.parent	= &dev->dev;
384 
385 	ret = -EBUSY;
386 	if (request_irq(dev->irq, gscps2_interrupt, IRQF_SHARED, ps2port->port->name, ps2port))
387 		goto fail_miserably;
388 
389 	if (ps2port->id != GSC_ID_KEYBOARD && ps2port->id != GSC_ID_MOUSE) {
390 		printk(KERN_WARNING PFX "Unsupported PS/2 port at 0x%08lx (id=%d) ignored\n",
391 				hpa, ps2port->id);
392 		ret = -ENODEV;
393 		goto fail;
394 	}
395 
396 #if 0
397 	if (!request_mem_region(hpa, GSC_STATUS + 4, ps2port->port.name))
398 		goto fail;
399 #endif
400 
401 	pr_info("serio: %s port at 0x%08lx irq %d @ %s\n",
402 		ps2port->port->name,
403 		hpa,
404 		ps2port->padev->irq,
405 		ps2port->port->phys);
406 
407 	serio_register_port(ps2port->port);
408 
409 	list_add_tail(&ps2port->node, &ps2port_list);
410 
411 	return 0;
412 
413 fail:
414 	free_irq(dev->irq, ps2port);
415 
416 fail_miserably:
417 	iounmap(ps2port->addr);
418 	release_mem_region(dev->hpa.start, GSC_STATUS + 4);
419 
420 fail_nomem:
421 	kfree(ps2port);
422 	kfree(serio);
423 	return ret;
424 }
425 
426 /**
427  * gscps2_remove() - Removes PS2 devices
428  * @dev: pointer to parisc_device which shall be removed
429  *
430  * @return: success/error report
431  */
432 
433 static void __exit gscps2_remove(struct parisc_device *dev)
434 {
435 	struct gscps2port *ps2port = dev_get_drvdata(&dev->dev);
436 
437 	serio_unregister_port(ps2port->port);
438 	free_irq(dev->irq, ps2port);
439 	gscps2_flush(ps2port);
440 	list_del(&ps2port->node);
441 	iounmap(ps2port->addr);
442 #if 0
443 	release_mem_region(dev->hpa, GSC_STATUS + 4);
444 #endif
445 	dev_set_drvdata(&dev->dev, NULL);
446 	kfree(ps2port);
447 }
448 
449 
450 static const struct parisc_device_id gscps2_device_tbl[] __initconst = {
451 	{ HPHW_FIO, HVERSION_REV_ANY_ID, HVERSION_ANY_ID, 0x00084 }, /* LASI PS/2 */
452 #ifdef DINO_TESTED
453 	{ HPHW_FIO, HVERSION_REV_ANY_ID, HVERSION_ANY_ID, 0x00096 }, /* DINO PS/2 */
454 #endif
455 	{ 0, }	/* 0 terminated list */
456 };
457 MODULE_DEVICE_TABLE(parisc, gscps2_device_tbl);
458 
459 static struct parisc_driver parisc_ps2_driver __refdata = {
460 	.name		= "gsc_ps2",
461 	.id_table	= gscps2_device_tbl,
462 	.probe		= gscps2_probe,
463 	.remove		= __exit_p(gscps2_remove),
464 };
465 
466 static int __init gscps2_init(void)
467 {
468 	register_parisc_driver(&parisc_ps2_driver);
469 	return 0;
470 }
471 
472 static void __exit gscps2_exit(void)
473 {
474 	unregister_parisc_driver(&parisc_ps2_driver);
475 }
476 
477 
478 module_init(gscps2_init);
479 module_exit(gscps2_exit);
480 
481