xref: /openbmc/qemu/hw/input/lm832x.c (revision 37677d7d)
1 /*
2  * National Semiconductor LM8322/8323 GPIO keyboard & PWM chips.
3  *
4  * Copyright (C) 2008 Nokia Corporation
5  * Written by Andrzej Zaborowski <andrew@openedhand.com>
6  *
7  * This program is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU General Public License as
9  * published by the Free Software Foundation; either version 2 or
10  * (at your option) version 3 of the License.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  * GNU General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License along
18  * with this program; if not, see <http://www.gnu.org/licenses/>.
19  */
20 
21 #include "qemu/osdep.h"
22 #include "hw/hw.h"
23 #include "hw/i2c/i2c.h"
24 #include "qemu/module.h"
25 #include "qemu/timer.h"
26 #include "ui/console.h"
27 
28 #define TYPE_LM8323 "lm8323"
29 #define LM8323(obj) OBJECT_CHECK(LM823KbdState, (obj), TYPE_LM8323)
30 
31 typedef struct {
32     I2CSlave parent_obj;
33 
34     uint8_t i2c_dir;
35     uint8_t i2c_cycle;
36     uint8_t reg;
37 
38     qemu_irq nirq;
39     uint16_t model;
40 
41     struct {
42         qemu_irq out[2];
43         int in[2][2];
44     } mux;
45 
46     uint8_t config;
47     uint8_t status;
48     uint8_t acttime;
49     uint8_t error;
50     uint8_t clock;
51 
52     struct {
53         uint16_t pull;
54         uint16_t mask;
55         uint16_t dir;
56         uint16_t level;
57         qemu_irq out[16];
58     } gpio;
59 
60     struct {
61         uint8_t dbnctime;
62         uint8_t size;
63         uint8_t start;
64         uint8_t len;
65         uint8_t fifo[16];
66     } kbd;
67 
68     struct {
69         uint16_t file[256];
70         uint8_t faddr;
71         uint8_t addr[3];
72         QEMUTimer *tm[3];
73     } pwm;
74 } LM823KbdState;
75 
76 #define INT_KEYPAD		(1 << 0)
77 #define INT_ERROR		(1 << 3)
78 #define INT_NOINIT		(1 << 4)
79 #define INT_PWMEND(n)		(1 << (5 + n))
80 
81 #define ERR_BADPAR		(1 << 0)
82 #define ERR_CMDUNK		(1 << 1)
83 #define ERR_KEYOVR		(1 << 2)
84 #define ERR_FIFOOVR		(1 << 6)
85 
86 static void lm_kbd_irq_update(LM823KbdState *s)
87 {
88     qemu_set_irq(s->nirq, !s->status);
89 }
90 
91 static void lm_kbd_gpio_update(LM823KbdState *s)
92 {
93 }
94 
95 static void lm_kbd_reset(LM823KbdState *s)
96 {
97     s->config = 0x80;
98     s->status = INT_NOINIT;
99     s->acttime = 125;
100     s->kbd.dbnctime = 3;
101     s->kbd.size = 0x33;
102     s->clock = 0x08;
103 
104     lm_kbd_irq_update(s);
105     lm_kbd_gpio_update(s);
106 }
107 
108 static void lm_kbd_error(LM823KbdState *s, int err)
109 {
110     s->error |= err;
111     s->status |= INT_ERROR;
112     lm_kbd_irq_update(s);
113 }
114 
115 static void lm_kbd_pwm_tick(LM823KbdState *s, int line)
116 {
117 }
118 
119 static void lm_kbd_pwm_start(LM823KbdState *s, int line)
120 {
121     lm_kbd_pwm_tick(s, line);
122 }
123 
124 static void lm_kbd_pwm0_tick(void *opaque)
125 {
126     lm_kbd_pwm_tick(opaque, 0);
127 }
128 static void lm_kbd_pwm1_tick(void *opaque)
129 {
130     lm_kbd_pwm_tick(opaque, 1);
131 }
132 static void lm_kbd_pwm2_tick(void *opaque)
133 {
134     lm_kbd_pwm_tick(opaque, 2);
135 }
136 
137 enum {
138     LM832x_CMD_READ_ID		= 0x80, /* Read chip ID. */
139     LM832x_CMD_WRITE_CFG	= 0x81, /* Set configuration item. */
140     LM832x_CMD_READ_INT		= 0x82, /* Get interrupt status. */
141     LM832x_CMD_RESET		= 0x83, /* Reset, same as external one */
142     LM823x_CMD_WRITE_PULL_DOWN	= 0x84, /* Select GPIO pull-up/down. */
143     LM832x_CMD_WRITE_PORT_SEL	= 0x85, /* Select GPIO in/out. */
144     LM832x_CMD_WRITE_PORT_STATE	= 0x86, /* Set GPIO pull-up/down. */
145     LM832x_CMD_READ_PORT_SEL	= 0x87, /* Get GPIO in/out. */
146     LM832x_CMD_READ_PORT_STATE	= 0x88, /* Get GPIO pull-up/down. */
147     LM832x_CMD_READ_FIFO	= 0x89, /* Read byte from FIFO. */
148     LM832x_CMD_RPT_READ_FIFO	= 0x8a, /* Read FIFO (no increment). */
149     LM832x_CMD_SET_ACTIVE	= 0x8b, /* Set active time. */
150     LM832x_CMD_READ_ERROR	= 0x8c, /* Get error status. */
151     LM832x_CMD_READ_ROTATOR	= 0x8e, /* Read rotator status. */
152     LM832x_CMD_SET_DEBOUNCE	= 0x8f, /* Set debouncing time. */
153     LM832x_CMD_SET_KEY_SIZE	= 0x90, /* Set keypad size. */
154     LM832x_CMD_READ_KEY_SIZE	= 0x91, /* Get keypad size. */
155     LM832x_CMD_READ_CFG		= 0x92, /* Get configuration item. */
156     LM832x_CMD_WRITE_CLOCK	= 0x93, /* Set clock config. */
157     LM832x_CMD_READ_CLOCK	= 0x94, /* Get clock config. */
158     LM832x_CMD_PWM_WRITE	= 0x95, /* Write PWM script. */
159     LM832x_CMD_PWM_START	= 0x96, /* Start PWM engine. */
160     LM832x_CMD_PWM_STOP		= 0x97, /* Stop PWM engine. */
161     LM832x_GENERAL_ERROR	= 0xff, /* There was one error.
162                                            Previously was represented by -1
163                                            This is not a command */
164 };
165 
166 #define LM832x_MAX_KPX		8
167 #define LM832x_MAX_KPY		12
168 
169 static uint8_t lm_kbd_read(LM823KbdState *s, int reg, int byte)
170 {
171     int ret;
172 
173     switch (reg) {
174     case LM832x_CMD_READ_ID:
175         ret = 0x0400;
176         break;
177 
178     case LM832x_CMD_READ_INT:
179         ret = s->status;
180         if (!(s->status & INT_NOINIT)) {
181             s->status = 0;
182             lm_kbd_irq_update(s);
183         }
184         break;
185 
186     case LM832x_CMD_READ_PORT_SEL:
187         ret = s->gpio.dir;
188         break;
189     case LM832x_CMD_READ_PORT_STATE:
190         ret = s->gpio.mask;
191         break;
192 
193     case LM832x_CMD_READ_FIFO:
194         if (s->kbd.len <= 1)
195             return 0x00;
196 
197         /* Example response from the two commands after a INT_KEYPAD
198          * interrupt caused by the key 0x3c being pressed:
199          * RPT_READ_FIFO: 55 bc 00 4e ff 0a 50 08 00 29 d9 08 01 c9 01
200          *     READ_FIFO: bc 00 00 4e ff 0a 50 08 00 29 d9 08 01 c9 01
201          * RPT_READ_FIFO: bc 00 00 4e ff 0a 50 08 00 29 d9 08 01 c9 01
202          *
203          * 55 is the code of the key release event serviced in the previous
204          * interrupt handling.
205          *
206          * TODO: find out whether the FIFO is advanced a single character
207          * before reading every byte or the whole size of the FIFO at the
208          * last LM832x_CMD_READ_FIFO.  This affects LM832x_CMD_RPT_READ_FIFO
209          * output in cases where there are more than one event in the FIFO.
210          * Assume 0xbc and 0x3c events are in the FIFO:
211          * RPT_READ_FIFO: 55 bc 3c 00 4e ff 0a 50 08 00 29 d9 08 01 c9
212          *     READ_FIFO: bc 3c 00 00 4e ff 0a 50 08 00 29 d9 08 01 c9
213          * Does RPT_READ_FIFO now return 0xbc and 0x3c or only 0x3c?
214          */
215         s->kbd.start ++;
216         s->kbd.start &= sizeof(s->kbd.fifo) - 1;
217         s->kbd.len --;
218 
219         return s->kbd.fifo[s->kbd.start];
220     case LM832x_CMD_RPT_READ_FIFO:
221         if (byte >= s->kbd.len)
222             return 0x00;
223 
224         return s->kbd.fifo[(s->kbd.start + byte) & (sizeof(s->kbd.fifo) - 1)];
225 
226     case LM832x_CMD_READ_ERROR:
227         return s->error;
228 
229     case LM832x_CMD_READ_ROTATOR:
230         return 0;
231 
232     case LM832x_CMD_READ_KEY_SIZE:
233         return s->kbd.size;
234 
235     case LM832x_CMD_READ_CFG:
236         return s->config & 0xf;
237 
238     case LM832x_CMD_READ_CLOCK:
239         return (s->clock & 0xfc) | 2;
240 
241     default:
242         lm_kbd_error(s, ERR_CMDUNK);
243         fprintf(stderr, "%s: unknown command %02x\n", __func__, reg);
244         return 0x00;
245     }
246 
247     return ret >> (byte << 3);
248 }
249 
250 static void lm_kbd_write(LM823KbdState *s, int reg, int byte, uint8_t value)
251 {
252     switch (reg) {
253     case LM832x_CMD_WRITE_CFG:
254         s->config = value;
255         /* This must be done whenever s->mux.in is updated (never).  */
256         if ((s->config >> 1) & 1)			/* MUX1EN */
257             qemu_set_irq(s->mux.out[0], s->mux.in[0][(s->config >> 0) & 1]);
258         if ((s->config >> 3) & 1)			/* MUX2EN */
259             qemu_set_irq(s->mux.out[0], s->mux.in[0][(s->config >> 2) & 1]);
260         /* TODO: check that this is issued only following the chip reset
261          * and not in the middle of operation and that it is followed by
262          * the GPIO ports re-resablishing through WRITE_PORT_SEL and
263          * WRITE_PORT_STATE (using a timer perhaps) and otherwise output
264          * warnings.  */
265         s->status = 0;
266         lm_kbd_irq_update(s);
267         s->kbd.len = 0;
268         s->kbd.start = 0;
269         s->reg = LM832x_GENERAL_ERROR;
270         break;
271 
272     case LM832x_CMD_RESET:
273         if (value == 0xaa)
274             lm_kbd_reset(s);
275         else
276             lm_kbd_error(s, ERR_BADPAR);
277         s->reg = LM832x_GENERAL_ERROR;
278         break;
279 
280     case LM823x_CMD_WRITE_PULL_DOWN:
281         if (!byte)
282             s->gpio.pull = value;
283         else {
284             s->gpio.pull |= value << 8;
285             lm_kbd_gpio_update(s);
286             s->reg = LM832x_GENERAL_ERROR;
287         }
288         break;
289     case LM832x_CMD_WRITE_PORT_SEL:
290         if (!byte)
291             s->gpio.dir = value;
292         else {
293             s->gpio.dir |= value << 8;
294             lm_kbd_gpio_update(s);
295             s->reg = LM832x_GENERAL_ERROR;
296         }
297         break;
298     case LM832x_CMD_WRITE_PORT_STATE:
299         if (!byte)
300             s->gpio.mask = value;
301         else {
302             s->gpio.mask |= value << 8;
303             lm_kbd_gpio_update(s);
304             s->reg = LM832x_GENERAL_ERROR;
305         }
306         break;
307 
308     case LM832x_CMD_SET_ACTIVE:
309         s->acttime = value;
310         s->reg = LM832x_GENERAL_ERROR;
311         break;
312 
313     case LM832x_CMD_SET_DEBOUNCE:
314         s->kbd.dbnctime = value;
315         s->reg = LM832x_GENERAL_ERROR;
316         if (!value)
317             lm_kbd_error(s, ERR_BADPAR);
318         break;
319 
320     case LM832x_CMD_SET_KEY_SIZE:
321         s->kbd.size = value;
322         s->reg = LM832x_GENERAL_ERROR;
323         if (
324                         (value & 0xf) < 3 || (value & 0xf) > LM832x_MAX_KPY ||
325                         (value >> 4) < 3 || (value >> 4) > LM832x_MAX_KPX)
326             lm_kbd_error(s, ERR_BADPAR);
327         break;
328 
329     case LM832x_CMD_WRITE_CLOCK:
330         s->clock = value;
331         s->reg = LM832x_GENERAL_ERROR;
332         if ((value & 3) && (value & 3) != 3) {
333             lm_kbd_error(s, ERR_BADPAR);
334             fprintf(stderr, "%s: invalid clock setting in RCPWM\n",
335                             __func__);
336         }
337         /* TODO: Validate that the command is only issued once */
338         break;
339 
340     case LM832x_CMD_PWM_WRITE:
341         if (byte == 0) {
342             if (!(value & 3) || (value >> 2) > 59) {
343                 lm_kbd_error(s, ERR_BADPAR);
344                 s->reg = LM832x_GENERAL_ERROR;
345                 break;
346             }
347 
348             s->pwm.faddr = value;
349             s->pwm.file[s->pwm.faddr] = 0;
350         } else if (byte == 1) {
351             s->pwm.file[s->pwm.faddr] |= value << 8;
352         } else if (byte == 2) {
353             s->pwm.file[s->pwm.faddr] |= value << 0;
354             s->reg = LM832x_GENERAL_ERROR;
355         }
356         break;
357     case LM832x_CMD_PWM_START:
358         s->reg = LM832x_GENERAL_ERROR;
359         if (!(value & 3) || (value >> 2) > 59) {
360             lm_kbd_error(s, ERR_BADPAR);
361             break;
362         }
363 
364         s->pwm.addr[(value & 3) - 1] = value >> 2;
365         lm_kbd_pwm_start(s, (value & 3) - 1);
366         break;
367     case LM832x_CMD_PWM_STOP:
368         s->reg = LM832x_GENERAL_ERROR;
369         if (!(value & 3)) {
370             lm_kbd_error(s, ERR_BADPAR);
371             break;
372         }
373 
374         timer_del(s->pwm.tm[(value & 3) - 1]);
375         break;
376 
377     case LM832x_GENERAL_ERROR:
378         lm_kbd_error(s, ERR_BADPAR);
379         break;
380     default:
381         lm_kbd_error(s, ERR_CMDUNK);
382         fprintf(stderr, "%s: unknown command %02x\n", __func__, reg);
383         break;
384     }
385 }
386 
387 static int lm_i2c_event(I2CSlave *i2c, enum i2c_event event)
388 {
389     LM823KbdState *s = LM8323(i2c);
390 
391     switch (event) {
392     case I2C_START_RECV:
393     case I2C_START_SEND:
394         s->i2c_cycle = 0;
395         s->i2c_dir = (event == I2C_START_SEND);
396         break;
397 
398     default:
399         break;
400     }
401 
402     return 0;
403 }
404 
405 static uint8_t lm_i2c_rx(I2CSlave *i2c)
406 {
407     LM823KbdState *s = LM8323(i2c);
408 
409     return lm_kbd_read(s, s->reg, s->i2c_cycle ++);
410 }
411 
412 static int lm_i2c_tx(I2CSlave *i2c, uint8_t data)
413 {
414     LM823KbdState *s = LM8323(i2c);
415 
416     if (!s->i2c_cycle)
417         s->reg = data;
418     else
419         lm_kbd_write(s, s->reg, s->i2c_cycle - 1, data);
420     s->i2c_cycle ++;
421 
422     return 0;
423 }
424 
425 static int lm_kbd_post_load(void *opaque, int version_id)
426 {
427     LM823KbdState *s = opaque;
428 
429     lm_kbd_irq_update(s);
430     lm_kbd_gpio_update(s);
431 
432     return 0;
433 }
434 
435 static const VMStateDescription vmstate_lm_kbd = {
436     .name = "LM8323",
437     .version_id = 0,
438     .minimum_version_id = 0,
439     .post_load = lm_kbd_post_load,
440     .fields = (VMStateField[]) {
441         VMSTATE_I2C_SLAVE(parent_obj, LM823KbdState),
442         VMSTATE_UINT8(i2c_dir, LM823KbdState),
443         VMSTATE_UINT8(i2c_cycle, LM823KbdState),
444         VMSTATE_UINT8(reg, LM823KbdState),
445         VMSTATE_UINT8(config, LM823KbdState),
446         VMSTATE_UINT8(status, LM823KbdState),
447         VMSTATE_UINT8(acttime, LM823KbdState),
448         VMSTATE_UINT8(error, LM823KbdState),
449         VMSTATE_UINT8(clock, LM823KbdState),
450         VMSTATE_UINT16(gpio.pull, LM823KbdState),
451         VMSTATE_UINT16(gpio.mask, LM823KbdState),
452         VMSTATE_UINT16(gpio.dir, LM823KbdState),
453         VMSTATE_UINT16(gpio.level, LM823KbdState),
454         VMSTATE_UINT8(kbd.dbnctime, LM823KbdState),
455         VMSTATE_UINT8(kbd.size, LM823KbdState),
456         VMSTATE_UINT8(kbd.start, LM823KbdState),
457         VMSTATE_UINT8(kbd.len, LM823KbdState),
458         VMSTATE_BUFFER(kbd.fifo, LM823KbdState),
459         VMSTATE_UINT16_ARRAY(pwm.file, LM823KbdState, 256),
460         VMSTATE_UINT8(pwm.faddr, LM823KbdState),
461         VMSTATE_BUFFER(pwm.addr, LM823KbdState),
462         VMSTATE_TIMER_PTR_ARRAY(pwm.tm, LM823KbdState, 3),
463         VMSTATE_END_OF_LIST()
464     }
465 };
466 
467 
468 static void lm8323_realize(DeviceState *dev, Error **errp)
469 {
470     LM823KbdState *s = LM8323(dev);
471 
472     s->model = 0x8323;
473     s->pwm.tm[0] = timer_new_ns(QEMU_CLOCK_VIRTUAL, lm_kbd_pwm0_tick, s);
474     s->pwm.tm[1] = timer_new_ns(QEMU_CLOCK_VIRTUAL, lm_kbd_pwm1_tick, s);
475     s->pwm.tm[2] = timer_new_ns(QEMU_CLOCK_VIRTUAL, lm_kbd_pwm2_tick, s);
476     qdev_init_gpio_out(dev, &s->nirq, 1);
477 
478     lm_kbd_reset(s);
479 
480     qemu_register_reset((void *) lm_kbd_reset, s);
481 }
482 
483 void lm832x_key_event(DeviceState *dev, int key, int state)
484 {
485     LM823KbdState *s = LM8323(dev);
486 
487     if ((s->status & INT_ERROR) && (s->error & ERR_FIFOOVR))
488         return;
489 
490     if (s->kbd.len >= sizeof(s->kbd.fifo)) {
491         lm_kbd_error(s, ERR_FIFOOVR);
492         return;
493     }
494 
495     s->kbd.fifo[(s->kbd.start + s->kbd.len ++) & (sizeof(s->kbd.fifo) - 1)] =
496             key | (state << 7);
497 
498     /* We never set ERR_KEYOVR because we support multiple keys fine.  */
499     s->status |= INT_KEYPAD;
500     lm_kbd_irq_update(s);
501 }
502 
503 static void lm8323_class_init(ObjectClass *klass, void *data)
504 {
505     DeviceClass *dc = DEVICE_CLASS(klass);
506     I2CSlaveClass *k = I2C_SLAVE_CLASS(klass);
507 
508     dc->realize = lm8323_realize;
509     k->event = lm_i2c_event;
510     k->recv = lm_i2c_rx;
511     k->send = lm_i2c_tx;
512     dc->vmsd = &vmstate_lm_kbd;
513 }
514 
515 static const TypeInfo lm8323_info = {
516     .name          = TYPE_LM8323,
517     .parent        = TYPE_I2C_SLAVE,
518     .instance_size = sizeof(LM823KbdState),
519     .class_init    = lm8323_class_init,
520 };
521 
522 static void lm832x_register_types(void)
523 {
524     type_register_static(&lm8323_info);
525 }
526 
527 type_init(lm832x_register_types)
528