xref: /openbmc/qemu/hw/input/lm832x.c (revision 6a0acfff)
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 "hw/irq.h"
25 #include "qemu/module.h"
26 #include "qemu/timer.h"
27 #include "sysemu/reset.h"
28 #include "ui/console.h"
29 
30 #define TYPE_LM8323 "lm8323"
31 #define LM8323(obj) OBJECT_CHECK(LM823KbdState, (obj), TYPE_LM8323)
32 
33 typedef struct {
34     I2CSlave parent_obj;
35 
36     uint8_t i2c_dir;
37     uint8_t i2c_cycle;
38     uint8_t reg;
39 
40     qemu_irq nirq;
41     uint16_t model;
42 
43     struct {
44         qemu_irq out[2];
45         int in[2][2];
46     } mux;
47 
48     uint8_t config;
49     uint8_t status;
50     uint8_t acttime;
51     uint8_t error;
52     uint8_t clock;
53 
54     struct {
55         uint16_t pull;
56         uint16_t mask;
57         uint16_t dir;
58         uint16_t level;
59         qemu_irq out[16];
60     } gpio;
61 
62     struct {
63         uint8_t dbnctime;
64         uint8_t size;
65         uint8_t start;
66         uint8_t len;
67         uint8_t fifo[16];
68     } kbd;
69 
70     struct {
71         uint16_t file[256];
72         uint8_t faddr;
73         uint8_t addr[3];
74         QEMUTimer *tm[3];
75     } pwm;
76 } LM823KbdState;
77 
78 #define INT_KEYPAD		(1 << 0)
79 #define INT_ERROR		(1 << 3)
80 #define INT_NOINIT		(1 << 4)
81 #define INT_PWMEND(n)		(1 << (5 + n))
82 
83 #define ERR_BADPAR		(1 << 0)
84 #define ERR_CMDUNK		(1 << 1)
85 #define ERR_KEYOVR		(1 << 2)
86 #define ERR_FIFOOVR		(1 << 6)
87 
88 static void lm_kbd_irq_update(LM823KbdState *s)
89 {
90     qemu_set_irq(s->nirq, !s->status);
91 }
92 
93 static void lm_kbd_gpio_update(LM823KbdState *s)
94 {
95 }
96 
97 static void lm_kbd_reset(LM823KbdState *s)
98 {
99     s->config = 0x80;
100     s->status = INT_NOINIT;
101     s->acttime = 125;
102     s->kbd.dbnctime = 3;
103     s->kbd.size = 0x33;
104     s->clock = 0x08;
105 
106     lm_kbd_irq_update(s);
107     lm_kbd_gpio_update(s);
108 }
109 
110 static void lm_kbd_error(LM823KbdState *s, int err)
111 {
112     s->error |= err;
113     s->status |= INT_ERROR;
114     lm_kbd_irq_update(s);
115 }
116 
117 static void lm_kbd_pwm_tick(LM823KbdState *s, int line)
118 {
119 }
120 
121 static void lm_kbd_pwm_start(LM823KbdState *s, int line)
122 {
123     lm_kbd_pwm_tick(s, line);
124 }
125 
126 static void lm_kbd_pwm0_tick(void *opaque)
127 {
128     lm_kbd_pwm_tick(opaque, 0);
129 }
130 static void lm_kbd_pwm1_tick(void *opaque)
131 {
132     lm_kbd_pwm_tick(opaque, 1);
133 }
134 static void lm_kbd_pwm2_tick(void *opaque)
135 {
136     lm_kbd_pwm_tick(opaque, 2);
137 }
138 
139 enum {
140     LM832x_CMD_READ_ID		= 0x80, /* Read chip ID. */
141     LM832x_CMD_WRITE_CFG	= 0x81, /* Set configuration item. */
142     LM832x_CMD_READ_INT		= 0x82, /* Get interrupt status. */
143     LM832x_CMD_RESET		= 0x83, /* Reset, same as external one */
144     LM823x_CMD_WRITE_PULL_DOWN	= 0x84, /* Select GPIO pull-up/down. */
145     LM832x_CMD_WRITE_PORT_SEL	= 0x85, /* Select GPIO in/out. */
146     LM832x_CMD_WRITE_PORT_STATE	= 0x86, /* Set GPIO pull-up/down. */
147     LM832x_CMD_READ_PORT_SEL	= 0x87, /* Get GPIO in/out. */
148     LM832x_CMD_READ_PORT_STATE	= 0x88, /* Get GPIO pull-up/down. */
149     LM832x_CMD_READ_FIFO	= 0x89, /* Read byte from FIFO. */
150     LM832x_CMD_RPT_READ_FIFO	= 0x8a, /* Read FIFO (no increment). */
151     LM832x_CMD_SET_ACTIVE	= 0x8b, /* Set active time. */
152     LM832x_CMD_READ_ERROR	= 0x8c, /* Get error status. */
153     LM832x_CMD_READ_ROTATOR	= 0x8e, /* Read rotator status. */
154     LM832x_CMD_SET_DEBOUNCE	= 0x8f, /* Set debouncing time. */
155     LM832x_CMD_SET_KEY_SIZE	= 0x90, /* Set keypad size. */
156     LM832x_CMD_READ_KEY_SIZE	= 0x91, /* Get keypad size. */
157     LM832x_CMD_READ_CFG		= 0x92, /* Get configuration item. */
158     LM832x_CMD_WRITE_CLOCK	= 0x93, /* Set clock config. */
159     LM832x_CMD_READ_CLOCK	= 0x94, /* Get clock config. */
160     LM832x_CMD_PWM_WRITE	= 0x95, /* Write PWM script. */
161     LM832x_CMD_PWM_START	= 0x96, /* Start PWM engine. */
162     LM832x_CMD_PWM_STOP		= 0x97, /* Stop PWM engine. */
163     LM832x_GENERAL_ERROR	= 0xff, /* There was one error.
164                                            Previously was represented by -1
165                                            This is not a command */
166 };
167 
168 #define LM832x_MAX_KPX		8
169 #define LM832x_MAX_KPY		12
170 
171 static uint8_t lm_kbd_read(LM823KbdState *s, int reg, int byte)
172 {
173     int ret;
174 
175     switch (reg) {
176     case LM832x_CMD_READ_ID:
177         ret = 0x0400;
178         break;
179 
180     case LM832x_CMD_READ_INT:
181         ret = s->status;
182         if (!(s->status & INT_NOINIT)) {
183             s->status = 0;
184             lm_kbd_irq_update(s);
185         }
186         break;
187 
188     case LM832x_CMD_READ_PORT_SEL:
189         ret = s->gpio.dir;
190         break;
191     case LM832x_CMD_READ_PORT_STATE:
192         ret = s->gpio.mask;
193         break;
194 
195     case LM832x_CMD_READ_FIFO:
196         if (s->kbd.len <= 1)
197             return 0x00;
198 
199         /* Example response from the two commands after a INT_KEYPAD
200          * interrupt caused by the key 0x3c being pressed:
201          * RPT_READ_FIFO: 55 bc 00 4e ff 0a 50 08 00 29 d9 08 01 c9 01
202          *     READ_FIFO: bc 00 00 4e ff 0a 50 08 00 29 d9 08 01 c9 01
203          * RPT_READ_FIFO: bc 00 00 4e ff 0a 50 08 00 29 d9 08 01 c9 01
204          *
205          * 55 is the code of the key release event serviced in the previous
206          * interrupt handling.
207          *
208          * TODO: find out whether the FIFO is advanced a single character
209          * before reading every byte or the whole size of the FIFO at the
210          * last LM832x_CMD_READ_FIFO.  This affects LM832x_CMD_RPT_READ_FIFO
211          * output in cases where there are more than one event in the FIFO.
212          * Assume 0xbc and 0x3c events are in the FIFO:
213          * RPT_READ_FIFO: 55 bc 3c 00 4e ff 0a 50 08 00 29 d9 08 01 c9
214          *     READ_FIFO: bc 3c 00 00 4e ff 0a 50 08 00 29 d9 08 01 c9
215          * Does RPT_READ_FIFO now return 0xbc and 0x3c or only 0x3c?
216          */
217         s->kbd.start ++;
218         s->kbd.start &= sizeof(s->kbd.fifo) - 1;
219         s->kbd.len --;
220 
221         return s->kbd.fifo[s->kbd.start];
222     case LM832x_CMD_RPT_READ_FIFO:
223         if (byte >= s->kbd.len)
224             return 0x00;
225 
226         return s->kbd.fifo[(s->kbd.start + byte) & (sizeof(s->kbd.fifo) - 1)];
227 
228     case LM832x_CMD_READ_ERROR:
229         return s->error;
230 
231     case LM832x_CMD_READ_ROTATOR:
232         return 0;
233 
234     case LM832x_CMD_READ_KEY_SIZE:
235         return s->kbd.size;
236 
237     case LM832x_CMD_READ_CFG:
238         return s->config & 0xf;
239 
240     case LM832x_CMD_READ_CLOCK:
241         return (s->clock & 0xfc) | 2;
242 
243     default:
244         lm_kbd_error(s, ERR_CMDUNK);
245         fprintf(stderr, "%s: unknown command %02x\n", __func__, reg);
246         return 0x00;
247     }
248 
249     return ret >> (byte << 3);
250 }
251 
252 static void lm_kbd_write(LM823KbdState *s, int reg, int byte, uint8_t value)
253 {
254     switch (reg) {
255     case LM832x_CMD_WRITE_CFG:
256         s->config = value;
257         /* This must be done whenever s->mux.in is updated (never).  */
258         if ((s->config >> 1) & 1)			/* MUX1EN */
259             qemu_set_irq(s->mux.out[0], s->mux.in[0][(s->config >> 0) & 1]);
260         if ((s->config >> 3) & 1)			/* MUX2EN */
261             qemu_set_irq(s->mux.out[0], s->mux.in[0][(s->config >> 2) & 1]);
262         /* TODO: check that this is issued only following the chip reset
263          * and not in the middle of operation and that it is followed by
264          * the GPIO ports re-resablishing through WRITE_PORT_SEL and
265          * WRITE_PORT_STATE (using a timer perhaps) and otherwise output
266          * warnings.  */
267         s->status = 0;
268         lm_kbd_irq_update(s);
269         s->kbd.len = 0;
270         s->kbd.start = 0;
271         s->reg = LM832x_GENERAL_ERROR;
272         break;
273 
274     case LM832x_CMD_RESET:
275         if (value == 0xaa)
276             lm_kbd_reset(s);
277         else
278             lm_kbd_error(s, ERR_BADPAR);
279         s->reg = LM832x_GENERAL_ERROR;
280         break;
281 
282     case LM823x_CMD_WRITE_PULL_DOWN:
283         if (!byte)
284             s->gpio.pull = value;
285         else {
286             s->gpio.pull |= value << 8;
287             lm_kbd_gpio_update(s);
288             s->reg = LM832x_GENERAL_ERROR;
289         }
290         break;
291     case LM832x_CMD_WRITE_PORT_SEL:
292         if (!byte)
293             s->gpio.dir = value;
294         else {
295             s->gpio.dir |= value << 8;
296             lm_kbd_gpio_update(s);
297             s->reg = LM832x_GENERAL_ERROR;
298         }
299         break;
300     case LM832x_CMD_WRITE_PORT_STATE:
301         if (!byte)
302             s->gpio.mask = value;
303         else {
304             s->gpio.mask |= value << 8;
305             lm_kbd_gpio_update(s);
306             s->reg = LM832x_GENERAL_ERROR;
307         }
308         break;
309 
310     case LM832x_CMD_SET_ACTIVE:
311         s->acttime = value;
312         s->reg = LM832x_GENERAL_ERROR;
313         break;
314 
315     case LM832x_CMD_SET_DEBOUNCE:
316         s->kbd.dbnctime = value;
317         s->reg = LM832x_GENERAL_ERROR;
318         if (!value)
319             lm_kbd_error(s, ERR_BADPAR);
320         break;
321 
322     case LM832x_CMD_SET_KEY_SIZE:
323         s->kbd.size = value;
324         s->reg = LM832x_GENERAL_ERROR;
325         if (
326                         (value & 0xf) < 3 || (value & 0xf) > LM832x_MAX_KPY ||
327                         (value >> 4) < 3 || (value >> 4) > LM832x_MAX_KPX)
328             lm_kbd_error(s, ERR_BADPAR);
329         break;
330 
331     case LM832x_CMD_WRITE_CLOCK:
332         s->clock = value;
333         s->reg = LM832x_GENERAL_ERROR;
334         if ((value & 3) && (value & 3) != 3) {
335             lm_kbd_error(s, ERR_BADPAR);
336             fprintf(stderr, "%s: invalid clock setting in RCPWM\n",
337                             __func__);
338         }
339         /* TODO: Validate that the command is only issued once */
340         break;
341 
342     case LM832x_CMD_PWM_WRITE:
343         if (byte == 0) {
344             if (!(value & 3) || (value >> 2) > 59) {
345                 lm_kbd_error(s, ERR_BADPAR);
346                 s->reg = LM832x_GENERAL_ERROR;
347                 break;
348             }
349 
350             s->pwm.faddr = value;
351             s->pwm.file[s->pwm.faddr] = 0;
352         } else if (byte == 1) {
353             s->pwm.file[s->pwm.faddr] |= value << 8;
354         } else if (byte == 2) {
355             s->pwm.file[s->pwm.faddr] |= value << 0;
356             s->reg = LM832x_GENERAL_ERROR;
357         }
358         break;
359     case LM832x_CMD_PWM_START:
360         s->reg = LM832x_GENERAL_ERROR;
361         if (!(value & 3) || (value >> 2) > 59) {
362             lm_kbd_error(s, ERR_BADPAR);
363             break;
364         }
365 
366         s->pwm.addr[(value & 3) - 1] = value >> 2;
367         lm_kbd_pwm_start(s, (value & 3) - 1);
368         break;
369     case LM832x_CMD_PWM_STOP:
370         s->reg = LM832x_GENERAL_ERROR;
371         if (!(value & 3)) {
372             lm_kbd_error(s, ERR_BADPAR);
373             break;
374         }
375 
376         timer_del(s->pwm.tm[(value & 3) - 1]);
377         break;
378 
379     case LM832x_GENERAL_ERROR:
380         lm_kbd_error(s, ERR_BADPAR);
381         break;
382     default:
383         lm_kbd_error(s, ERR_CMDUNK);
384         fprintf(stderr, "%s: unknown command %02x\n", __func__, reg);
385         break;
386     }
387 }
388 
389 static int lm_i2c_event(I2CSlave *i2c, enum i2c_event event)
390 {
391     LM823KbdState *s = LM8323(i2c);
392 
393     switch (event) {
394     case I2C_START_RECV:
395     case I2C_START_SEND:
396         s->i2c_cycle = 0;
397         s->i2c_dir = (event == I2C_START_SEND);
398         break;
399 
400     default:
401         break;
402     }
403 
404     return 0;
405 }
406 
407 static uint8_t lm_i2c_rx(I2CSlave *i2c)
408 {
409     LM823KbdState *s = LM8323(i2c);
410 
411     return lm_kbd_read(s, s->reg, s->i2c_cycle ++);
412 }
413 
414 static int lm_i2c_tx(I2CSlave *i2c, uint8_t data)
415 {
416     LM823KbdState *s = LM8323(i2c);
417 
418     if (!s->i2c_cycle)
419         s->reg = data;
420     else
421         lm_kbd_write(s, s->reg, s->i2c_cycle - 1, data);
422     s->i2c_cycle ++;
423 
424     return 0;
425 }
426 
427 static int lm_kbd_post_load(void *opaque, int version_id)
428 {
429     LM823KbdState *s = opaque;
430 
431     lm_kbd_irq_update(s);
432     lm_kbd_gpio_update(s);
433 
434     return 0;
435 }
436 
437 static const VMStateDescription vmstate_lm_kbd = {
438     .name = "LM8323",
439     .version_id = 0,
440     .minimum_version_id = 0,
441     .post_load = lm_kbd_post_load,
442     .fields = (VMStateField[]) {
443         VMSTATE_I2C_SLAVE(parent_obj, LM823KbdState),
444         VMSTATE_UINT8(i2c_dir, LM823KbdState),
445         VMSTATE_UINT8(i2c_cycle, LM823KbdState),
446         VMSTATE_UINT8(reg, LM823KbdState),
447         VMSTATE_UINT8(config, LM823KbdState),
448         VMSTATE_UINT8(status, LM823KbdState),
449         VMSTATE_UINT8(acttime, LM823KbdState),
450         VMSTATE_UINT8(error, LM823KbdState),
451         VMSTATE_UINT8(clock, LM823KbdState),
452         VMSTATE_UINT16(gpio.pull, LM823KbdState),
453         VMSTATE_UINT16(gpio.mask, LM823KbdState),
454         VMSTATE_UINT16(gpio.dir, LM823KbdState),
455         VMSTATE_UINT16(gpio.level, LM823KbdState),
456         VMSTATE_UINT8(kbd.dbnctime, LM823KbdState),
457         VMSTATE_UINT8(kbd.size, LM823KbdState),
458         VMSTATE_UINT8(kbd.start, LM823KbdState),
459         VMSTATE_UINT8(kbd.len, LM823KbdState),
460         VMSTATE_BUFFER(kbd.fifo, LM823KbdState),
461         VMSTATE_UINT16_ARRAY(pwm.file, LM823KbdState, 256),
462         VMSTATE_UINT8(pwm.faddr, LM823KbdState),
463         VMSTATE_BUFFER(pwm.addr, LM823KbdState),
464         VMSTATE_TIMER_PTR_ARRAY(pwm.tm, LM823KbdState, 3),
465         VMSTATE_END_OF_LIST()
466     }
467 };
468 
469 
470 static void lm8323_realize(DeviceState *dev, Error **errp)
471 {
472     LM823KbdState *s = LM8323(dev);
473 
474     s->model = 0x8323;
475     s->pwm.tm[0] = timer_new_ns(QEMU_CLOCK_VIRTUAL, lm_kbd_pwm0_tick, s);
476     s->pwm.tm[1] = timer_new_ns(QEMU_CLOCK_VIRTUAL, lm_kbd_pwm1_tick, s);
477     s->pwm.tm[2] = timer_new_ns(QEMU_CLOCK_VIRTUAL, lm_kbd_pwm2_tick, s);
478     qdev_init_gpio_out(dev, &s->nirq, 1);
479 
480     lm_kbd_reset(s);
481 
482     qemu_register_reset((void *) lm_kbd_reset, s);
483 }
484 
485 void lm832x_key_event(DeviceState *dev, int key, int state)
486 {
487     LM823KbdState *s = LM8323(dev);
488 
489     if ((s->status & INT_ERROR) && (s->error & ERR_FIFOOVR))
490         return;
491 
492     if (s->kbd.len >= sizeof(s->kbd.fifo)) {
493         lm_kbd_error(s, ERR_FIFOOVR);
494         return;
495     }
496 
497     s->kbd.fifo[(s->kbd.start + s->kbd.len ++) & (sizeof(s->kbd.fifo) - 1)] =
498             key | (state << 7);
499 
500     /* We never set ERR_KEYOVR because we support multiple keys fine.  */
501     s->status |= INT_KEYPAD;
502     lm_kbd_irq_update(s);
503 }
504 
505 static void lm8323_class_init(ObjectClass *klass, void *data)
506 {
507     DeviceClass *dc = DEVICE_CLASS(klass);
508     I2CSlaveClass *k = I2C_SLAVE_CLASS(klass);
509 
510     dc->realize = lm8323_realize;
511     k->event = lm_i2c_event;
512     k->recv = lm_i2c_rx;
513     k->send = lm_i2c_tx;
514     dc->vmsd = &vmstate_lm_kbd;
515 }
516 
517 static const TypeInfo lm8323_info = {
518     .name          = TYPE_LM8323,
519     .parent        = TYPE_I2C_SLAVE,
520     .instance_size = sizeof(LM823KbdState),
521     .class_init    = lm8323_class_init,
522 };
523 
524 static void lm832x_register_types(void)
525 {
526     type_register_static(&lm8323_info);
527 }
528 
529 type_init(lm832x_register_types)
530