xref: /linux/drivers/input/serio/gscps2.c (revision 7a9b709e7cc5ce1ffb84ce07bf6d157e1de758df) 
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 	} while (true);
223 }
224 
225 static bool gscps2_report_data(struct gscps2port *ps2port)
226 {
227 	unsigned int rxflags;
228 	u8 data, status;
229 
230 	while (ps2port->act != ps2port->append) {
231 		/*
232 		 * Did new data arrived while we read existing data ?
233 		 * If yes, exit now and let the new irq handler start
234 		 * over again.
235 		 */
236 		if (gscps2_readb_status(ps2port->addr) & GSC_STAT_CMPINTR)
237 			return true;
238 
239 		status = ps2port->buffer[ps2port->act].str;
240 		data   = ps2port->buffer[ps2port->act].data;
241 
242 		ps2port->act = (ps2port->act + 1) & BUFFER_SIZE;
243 		rxflags = ((status & GSC_STAT_TERR) ? SERIO_TIMEOUT : 0 ) |
244 			  ((status & GSC_STAT_PERR) ? SERIO_PARITY  : 0 );
245 
246 		serio_interrupt(ps2port->port, data, rxflags);
247 	}
248 
249 	return false;
250 }
251 
252 /**
253  * gscps2_interrupt() - Interruption service routine
254  * @irq: interrupt number which triggered (unused)
255  * @dev: device pointer (unused)
256  *
257  * This function reads received PS/2 bytes and processes them on
258  * all interfaces.
259  * The problematic part here is, that the keyboard and mouse PS/2 port
260  * share the same interrupt and it's not possible to send data if any
261  * one of them holds input data. To solve this problem we try to receive
262  * the data as fast as possible and handle the reporting to the upper layer
263  * later.
264  */
265 
266 static irqreturn_t gscps2_interrupt(int irq, void *dev)
267 {
268 	struct gscps2port *ps2port;
269 
270 	list_for_each_entry(ps2port, &ps2port_list, node) {
271 		guard(spinlock_irqsave)(&ps2port->lock);
272 
273 		gscps2_read_data(ps2port);
274 	} /* list_for_each_entry */
275 
276 	/* all data was read from the ports - now report the data to upper layer */
277 	list_for_each_entry(ps2port, &ps2port_list, node) {
278 		if (gscps2_report_data(ps2port)) {
279 			/* More data ready - break early to restart interrupt */
280 			break;
281 		}
282 	}
283 
284 	return IRQ_HANDLED;
285 }
286 
287 
288 /*
289  * gscps2_write() - send a byte out through the aux interface.
290  */
291 
292 static int gscps2_write(struct serio *port, unsigned char data)
293 {
294 	struct gscps2port *ps2port = port->port_data;
295 
296 	if (!gscps2_writeb_output(ps2port, data)) {
297 		printk(KERN_DEBUG PFX "sending byte %#x failed.\n", data);
298 		return -1;
299 	}
300 	return 0;
301 }
302 
303 /*
304  * gscps2_open() is called when a port is opened by the higher layer.
305  * It resets and enables the port.
306  */
307 
308 static int gscps2_open(struct serio *port)
309 {
310 	struct gscps2port *ps2port = port->port_data;
311 
312 	gscps2_reset(ps2port);
313 
314 	/* enable it */
315 	gscps2_enable(ps2port, ENABLE);
316 
317 	gscps2_interrupt(0, NULL);
318 
319 	return 0;
320 }
321 
322 /*
323  * gscps2_close() disables the port
324  */
325 
326 static void gscps2_close(struct serio *port)
327 {
328 	struct gscps2port *ps2port = port->port_data;
329 	gscps2_enable(ps2port, DISABLE);
330 }
331 
332 /**
333  * gscps2_probe() - Probes PS2 devices
334  * @dev: pointer to parisc_device struct which will be probed
335  *
336  * @return: success/error report
337  */
338 
339 static int __init gscps2_probe(struct parisc_device *dev)
340 {
341 	struct gscps2port *ps2port;
342 	struct serio *serio;
343 	unsigned long hpa = dev->hpa.start;
344 	int ret;
345 
346 	if (!dev->irq)
347 		return -ENODEV;
348 
349 	/* Offset for DINO PS/2. Works with LASI even */
350 	if (dev->id.sversion == 0x96)
351 		hpa += GSC_DINO_OFFSET;
352 
353 	ps2port = kzalloc(sizeof(*ps2port), GFP_KERNEL);
354 	serio = kzalloc(sizeof(*serio), GFP_KERNEL);
355 	if (!ps2port || !serio) {
356 		ret = -ENOMEM;
357 		goto fail_nomem;
358 	}
359 
360 	dev_set_drvdata(&dev->dev, ps2port);
361 
362 	ps2port->port = serio;
363 	ps2port->padev = dev;
364 	ps2port->addr = ioremap(hpa, GSC_STATUS + 4);
365 	if (!ps2port->addr) {
366 		ret = -ENOMEM;
367 		goto fail_nomem;
368 	}
369 	spin_lock_init(&ps2port->lock);
370 
371 	gscps2_reset(ps2port);
372 	ps2port->id = readb(ps2port->addr + GSC_ID) & 0x0f;
373 
374 	snprintf(serio->name, sizeof(serio->name), "gsc-ps2-%s",
375 		 (ps2port->id == GSC_ID_KEYBOARD) ? "keyboard" : "mouse");
376 	strscpy(serio->phys, dev_name(&dev->dev), sizeof(serio->phys));
377 	serio->id.type		= SERIO_8042;
378 	serio->write		= gscps2_write;
379 	serio->open		= gscps2_open;
380 	serio->close		= gscps2_close;
381 	serio->port_data	= ps2port;
382 	serio->dev.parent	= &dev->dev;
383 
384 	ret = -EBUSY;
385 	if (request_irq(dev->irq, gscps2_interrupt, IRQF_SHARED, ps2port->port->name, ps2port))
386 		goto fail_miserably;
387 
388 	if (ps2port->id != GSC_ID_KEYBOARD && ps2port->id != GSC_ID_MOUSE) {
389 		printk(KERN_WARNING PFX "Unsupported PS/2 port at 0x%08lx (id=%d) ignored\n",
390 				hpa, ps2port->id);
391 		ret = -ENODEV;
392 		goto fail;
393 	}
394 
395 #if 0
396 	if (!request_mem_region(hpa, GSC_STATUS + 4, ps2port->port.name))
397 		goto fail;
398 #endif
399 
400 	pr_info("serio: %s port at 0x%08lx irq %d @ %s\n",
401 		ps2port->port->name,
402 		hpa,
403 		ps2port->padev->irq,
404 		ps2port->port->phys);
405 
406 	serio_register_port(ps2port->port);
407 
408 	list_add_tail(&ps2port->node, &ps2port_list);
409 
410 	return 0;
411 
412 fail:
413 	free_irq(dev->irq, ps2port);
414 
415 fail_miserably:
416 	iounmap(ps2port->addr);
417 	release_mem_region(dev->hpa.start, GSC_STATUS + 4);
418 
419 fail_nomem:
420 	kfree(ps2port);
421 	kfree(serio);
422 	return ret;
423 }
424 
425 /**
426  * gscps2_remove() - Removes PS2 devices
427  * @dev: pointer to parisc_device which shall be removed
428  *
429  * @return: success/error report
430  */
431 
432 static void __exit gscps2_remove(struct parisc_device *dev)
433 {
434 	struct gscps2port *ps2port = dev_get_drvdata(&dev->dev);
435 
436 	serio_unregister_port(ps2port->port);
437 	free_irq(dev->irq, ps2port);
438 	gscps2_flush(ps2port);
439 	list_del(&ps2port->node);
440 	iounmap(ps2port->addr);
441 #if 0
442 	release_mem_region(dev->hpa, GSC_STATUS + 4);
443 #endif
444 	dev_set_drvdata(&dev->dev, NULL);
445 	kfree(ps2port);
446 }
447 
448 
449 static const struct parisc_device_id gscps2_device_tbl[] __initconst = {
450 	{ HPHW_FIO, HVERSION_REV_ANY_ID, HVERSION_ANY_ID, 0x00084 }, /* LASI PS/2 */
451 #ifdef DINO_TESTED
452 	{ HPHW_FIO, HVERSION_REV_ANY_ID, HVERSION_ANY_ID, 0x00096 }, /* DINO PS/2 */
453 #endif
454 	{ 0, }	/* 0 terminated list */
455 };
456 MODULE_DEVICE_TABLE(parisc, gscps2_device_tbl);
457 
458 static struct parisc_driver parisc_ps2_driver __refdata = {
459 	.name		= "gsc_ps2",
460 	.id_table	= gscps2_device_tbl,
461 	.probe		= gscps2_probe,
462 	.remove		= __exit_p(gscps2_remove),
463 };
464 
465 static int __init gscps2_init(void)
466 {
467 	register_parisc_driver(&parisc_ps2_driver);
468 	return 0;
469 }
470 
471 static void __exit gscps2_exit(void)
472 {
473 	unregister_parisc_driver(&parisc_ps2_driver);
474 }
475 
476 
477 module_init(gscps2_init);
478 module_exit(gscps2_exit);
479 
480