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
wait_TBE(char __iomem * addr)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
gscps2_flush(struct gscps2port * ps2port)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
gscps2_writeb_output(struct gscps2port * ps2port,u8 data)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
gscps2_enable(struct gscps2port * ps2port,int enable)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
gscps2_reset(struct gscps2port * ps2port)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
gscps2_read_data(struct gscps2port * ps2port)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
gscps2_report_data(struct gscps2port * ps2port)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
gscps2_interrupt(int irq,void * dev)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
gscps2_write(struct serio * port,unsigned char data)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
gscps2_open(struct serio * port)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
gscps2_close(struct serio * port)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
gscps2_probe(struct parisc_device * dev)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
gscps2_remove(struct parisc_device * dev)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
gscps2_init(void)465 static int __init gscps2_init(void)
466 {
467 register_parisc_driver(&parisc_ps2_driver);
468 return 0;
469 }
470
gscps2_exit(void)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