xref: /openbmc/qemu/hw/input/lm832x.c (revision a68694cd)
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/i2c/i2c.h"
23 #include "hw/irq.h"
24 #include "migration/vmstate.h"
25 #include "qemu/module.h"
26 #include "qemu/timer.h"
27 #include "ui/console.h"
28 #include "qom/object.h"
29 
30 #define TYPE_LM8323 "lm8323"
31 typedef struct LM823KbdState LM823KbdState;
32 DECLARE_INSTANCE_CHECKER(LM823KbdState, LM8323,
33                          TYPE_LM8323)
34 
35 struct LM823KbdState {
36     I2CSlave parent_obj;
37 
38     uint8_t i2c_dir;
39     uint8_t i2c_cycle;
40     uint8_t reg;
41 
42     qemu_irq nirq;
43     uint16_t model;
44 
45     struct {
46         qemu_irq out[2];
47         int in[2][2];
48     } mux;
49 
50     uint8_t config;
51     uint8_t status;
52     uint8_t acttime;
53     uint8_t error;
54     uint8_t clock;
55 
56     struct {
57         uint16_t pull;
58         uint16_t mask;
59         uint16_t dir;
60         uint16_t level;
61         qemu_irq out[16];
62     } gpio;
63 
64     struct {
65         uint8_t dbnctime;
66         uint8_t size;
67         uint8_t start;
68         uint8_t len;
69         uint8_t fifo[16];
70     } kbd;
71 
72     struct {
73         uint16_t file[256];
74         uint8_t faddr;
75         uint8_t addr[3];
76         QEMUTimer *tm[3];
77     } pwm;
78 };
79 
80 #define INT_KEYPAD		(1 << 0)
81 #define INT_ERROR		(1 << 3)
82 #define INT_NOINIT		(1 << 4)
83 #define INT_PWMEND(n)		(1 << (5 + n))
84 
85 #define ERR_BADPAR		(1 << 0)
86 #define ERR_CMDUNK		(1 << 1)
87 #define ERR_KEYOVR		(1 << 2)
88 #define ERR_FIFOOVR		(1 << 6)
89 
90 static void lm_kbd_irq_update(LM823KbdState *s)
91 {
92     qemu_set_irq(s->nirq, !s->status);
93 }
94 
95 static void lm_kbd_gpio_update(LM823KbdState *s)
96 {
97 }
98 
99 static void lm_kbd_reset(DeviceState *dev)
100 {
101     LM823KbdState *s = LM8323(dev);
102 
103     s->config = 0x80;
104     s->status = INT_NOINIT;
105     s->acttime = 125;
106     s->kbd.dbnctime = 3;
107     s->kbd.size = 0x33;
108     s->clock = 0x08;
109 
110     lm_kbd_irq_update(s);
111     lm_kbd_gpio_update(s);
112 }
113 
114 static void lm_kbd_error(LM823KbdState *s, int err)
115 {
116     s->error |= err;
117     s->status |= INT_ERROR;
118     lm_kbd_irq_update(s);
119 }
120 
121 static void lm_kbd_pwm_tick(LM823KbdState *s, int line)
122 {
123 }
124 
125 static void lm_kbd_pwm_start(LM823KbdState *s, int line)
126 {
127     lm_kbd_pwm_tick(s, line);
128 }
129 
130 static void lm_kbd_pwm0_tick(void *opaque)
131 {
132     lm_kbd_pwm_tick(opaque, 0);
133 }
134 static void lm_kbd_pwm1_tick(void *opaque)
135 {
136     lm_kbd_pwm_tick(opaque, 1);
137 }
138 static void lm_kbd_pwm2_tick(void *opaque)
139 {
140     lm_kbd_pwm_tick(opaque, 2);
141 }
142 
143 enum {
144     LM832x_CMD_READ_ID		= 0x80, /* Read chip ID. */
145     LM832x_CMD_WRITE_CFG	= 0x81, /* Set configuration item. */
146     LM832x_CMD_READ_INT		= 0x82, /* Get interrupt status. */
147     LM832x_CMD_RESET		= 0x83, /* Reset, same as external one */
148     LM823x_CMD_WRITE_PULL_DOWN	= 0x84, /* Select GPIO pull-up/down. */
149     LM832x_CMD_WRITE_PORT_SEL	= 0x85, /* Select GPIO in/out. */
150     LM832x_CMD_WRITE_PORT_STATE	= 0x86, /* Set GPIO pull-up/down. */
151     LM832x_CMD_READ_PORT_SEL	= 0x87, /* Get GPIO in/out. */
152     LM832x_CMD_READ_PORT_STATE	= 0x88, /* Get GPIO pull-up/down. */
153     LM832x_CMD_READ_FIFO	= 0x89, /* Read byte from FIFO. */
154     LM832x_CMD_RPT_READ_FIFO	= 0x8a, /* Read FIFO (no increment). */
155     LM832x_CMD_SET_ACTIVE	= 0x8b, /* Set active time. */
156     LM832x_CMD_READ_ERROR	= 0x8c, /* Get error status. */
157     LM832x_CMD_READ_ROTATOR	= 0x8e, /* Read rotator status. */
158     LM832x_CMD_SET_DEBOUNCE	= 0x8f, /* Set debouncing time. */
159     LM832x_CMD_SET_KEY_SIZE	= 0x90, /* Set keypad size. */
160     LM832x_CMD_READ_KEY_SIZE	= 0x91, /* Get keypad size. */
161     LM832x_CMD_READ_CFG		= 0x92, /* Get configuration item. */
162     LM832x_CMD_WRITE_CLOCK	= 0x93, /* Set clock config. */
163     LM832x_CMD_READ_CLOCK	= 0x94, /* Get clock config. */
164     LM832x_CMD_PWM_WRITE	= 0x95, /* Write PWM script. */
165     LM832x_CMD_PWM_START	= 0x96, /* Start PWM engine. */
166     LM832x_CMD_PWM_STOP		= 0x97, /* Stop PWM engine. */
167     LM832x_GENERAL_ERROR	= 0xff, /* There was one error.
168                                            Previously was represented by -1
169                                            This is not a command */
170 };
171 
172 #define LM832x_MAX_KPX		8
173 #define LM832x_MAX_KPY		12
174 
175 static uint8_t lm_kbd_read(LM823KbdState *s, int reg, int byte)
176 {
177     int ret;
178 
179     switch (reg) {
180     case LM832x_CMD_READ_ID:
181         ret = 0x0400;
182         break;
183 
184     case LM832x_CMD_READ_INT:
185         ret = s->status;
186         if (!(s->status & INT_NOINIT)) {
187             s->status = 0;
188             lm_kbd_irq_update(s);
189         }
190         break;
191 
192     case LM832x_CMD_READ_PORT_SEL:
193         ret = s->gpio.dir;
194         break;
195     case LM832x_CMD_READ_PORT_STATE:
196         ret = s->gpio.mask;
197         break;
198 
199     case LM832x_CMD_READ_FIFO:
200         if (s->kbd.len <= 1)
201             return 0x00;
202 
203         /* Example response from the two commands after a INT_KEYPAD
204          * interrupt caused by the key 0x3c being pressed:
205          * RPT_READ_FIFO: 55 bc 00 4e ff 0a 50 08 00 29 d9 08 01 c9 01
206          *     READ_FIFO: bc 00 00 4e ff 0a 50 08 00 29 d9 08 01 c9 01
207          * RPT_READ_FIFO: bc 00 00 4e ff 0a 50 08 00 29 d9 08 01 c9 01
208          *
209          * 55 is the code of the key release event serviced in the previous
210          * interrupt handling.
211          *
212          * TODO: find out whether the FIFO is advanced a single character
213          * before reading every byte or the whole size of the FIFO at the
214          * last LM832x_CMD_READ_FIFO.  This affects LM832x_CMD_RPT_READ_FIFO
215          * output in cases where there are more than one event in the FIFO.
216          * Assume 0xbc and 0x3c events are in the FIFO:
217          * RPT_READ_FIFO: 55 bc 3c 00 4e ff 0a 50 08 00 29 d9 08 01 c9
218          *     READ_FIFO: bc 3c 00 00 4e ff 0a 50 08 00 29 d9 08 01 c9
219          * Does RPT_READ_FIFO now return 0xbc and 0x3c or only 0x3c?
220          */
221         s->kbd.start ++;
222         s->kbd.start &= sizeof(s->kbd.fifo) - 1;
223         s->kbd.len --;
224 
225         return s->kbd.fifo[s->kbd.start];
226     case LM832x_CMD_RPT_READ_FIFO:
227         if (byte >= s->kbd.len)
228             return 0x00;
229 
230         return s->kbd.fifo[(s->kbd.start + byte) & (sizeof(s->kbd.fifo) - 1)];
231 
232     case LM832x_CMD_READ_ERROR:
233         return s->error;
234 
235     case LM832x_CMD_READ_ROTATOR:
236         return 0;
237 
238     case LM832x_CMD_READ_KEY_SIZE:
239         return s->kbd.size;
240 
241     case LM832x_CMD_READ_CFG:
242         return s->config & 0xf;
243 
244     case LM832x_CMD_READ_CLOCK:
245         return (s->clock & 0xfc) | 2;
246 
247     default:
248         lm_kbd_error(s, ERR_CMDUNK);
249         fprintf(stderr, "%s: unknown command %02x\n", __func__, reg);
250         return 0x00;
251     }
252 
253     return ret >> (byte << 3);
254 }
255 
256 static void lm_kbd_write(LM823KbdState *s, int reg, int byte, uint8_t value)
257 {
258     switch (reg) {
259     case LM832x_CMD_WRITE_CFG:
260         s->config = value;
261         /* This must be done whenever s->mux.in is updated (never).  */
262         if ((s->config >> 1) & 1)			/* MUX1EN */
263             qemu_set_irq(s->mux.out[0], s->mux.in[0][(s->config >> 0) & 1]);
264         if ((s->config >> 3) & 1)			/* MUX2EN */
265             qemu_set_irq(s->mux.out[0], s->mux.in[0][(s->config >> 2) & 1]);
266         /* TODO: check that this is issued only following the chip reset
267          * and not in the middle of operation and that it is followed by
268          * the GPIO ports re-resablishing through WRITE_PORT_SEL and
269          * WRITE_PORT_STATE (using a timer perhaps) and otherwise output
270          * warnings.  */
271         s->status = 0;
272         lm_kbd_irq_update(s);
273         s->kbd.len = 0;
274         s->kbd.start = 0;
275         s->reg = LM832x_GENERAL_ERROR;
276         break;
277 
278     case LM832x_CMD_RESET:
279         if (value == 0xaa)
280             lm_kbd_reset(DEVICE(s));
281         else
282             lm_kbd_error(s, ERR_BADPAR);
283         s->reg = LM832x_GENERAL_ERROR;
284         break;
285 
286     case LM823x_CMD_WRITE_PULL_DOWN:
287         if (!byte)
288             s->gpio.pull = value;
289         else {
290             s->gpio.pull |= value << 8;
291             lm_kbd_gpio_update(s);
292             s->reg = LM832x_GENERAL_ERROR;
293         }
294         break;
295     case LM832x_CMD_WRITE_PORT_SEL:
296         if (!byte)
297             s->gpio.dir = value;
298         else {
299             s->gpio.dir |= value << 8;
300             lm_kbd_gpio_update(s);
301             s->reg = LM832x_GENERAL_ERROR;
302         }
303         break;
304     case LM832x_CMD_WRITE_PORT_STATE:
305         if (!byte)
306             s->gpio.mask = value;
307         else {
308             s->gpio.mask |= value << 8;
309             lm_kbd_gpio_update(s);
310             s->reg = LM832x_GENERAL_ERROR;
311         }
312         break;
313 
314     case LM832x_CMD_SET_ACTIVE:
315         s->acttime = value;
316         s->reg = LM832x_GENERAL_ERROR;
317         break;
318 
319     case LM832x_CMD_SET_DEBOUNCE:
320         s->kbd.dbnctime = value;
321         s->reg = LM832x_GENERAL_ERROR;
322         if (!value)
323             lm_kbd_error(s, ERR_BADPAR);
324         break;
325 
326     case LM832x_CMD_SET_KEY_SIZE:
327         s->kbd.size = value;
328         s->reg = LM832x_GENERAL_ERROR;
329         if (
330                         (value & 0xf) < 3 || (value & 0xf) > LM832x_MAX_KPY ||
331                         (value >> 4) < 3 || (value >> 4) > LM832x_MAX_KPX)
332             lm_kbd_error(s, ERR_BADPAR);
333         break;
334 
335     case LM832x_CMD_WRITE_CLOCK:
336         s->clock = value;
337         s->reg = LM832x_GENERAL_ERROR;
338         if ((value & 3) && (value & 3) != 3) {
339             lm_kbd_error(s, ERR_BADPAR);
340             fprintf(stderr, "%s: invalid clock setting in RCPWM\n",
341                             __func__);
342         }
343         /* TODO: Validate that the command is only issued once */
344         break;
345 
346     case LM832x_CMD_PWM_WRITE:
347         if (byte == 0) {
348             if (!(value & 3) || (value >> 2) > 59) {
349                 lm_kbd_error(s, ERR_BADPAR);
350                 s->reg = LM832x_GENERAL_ERROR;
351                 break;
352             }
353 
354             s->pwm.faddr = value;
355             s->pwm.file[s->pwm.faddr] = 0;
356         } else if (byte == 1) {
357             s->pwm.file[s->pwm.faddr] |= value << 8;
358         } else if (byte == 2) {
359             s->pwm.file[s->pwm.faddr] |= value << 0;
360             s->reg = LM832x_GENERAL_ERROR;
361         }
362         break;
363     case LM832x_CMD_PWM_START:
364         s->reg = LM832x_GENERAL_ERROR;
365         if (!(value & 3) || (value >> 2) > 59) {
366             lm_kbd_error(s, ERR_BADPAR);
367             break;
368         }
369 
370         s->pwm.addr[(value & 3) - 1] = value >> 2;
371         lm_kbd_pwm_start(s, (value & 3) - 1);
372         break;
373     case LM832x_CMD_PWM_STOP:
374         s->reg = LM832x_GENERAL_ERROR;
375         if (!(value & 3)) {
376             lm_kbd_error(s, ERR_BADPAR);
377             break;
378         }
379 
380         timer_del(s->pwm.tm[(value & 3) - 1]);
381         break;
382 
383     case LM832x_GENERAL_ERROR:
384         lm_kbd_error(s, ERR_BADPAR);
385         break;
386     default:
387         lm_kbd_error(s, ERR_CMDUNK);
388         fprintf(stderr, "%s: unknown command %02x\n", __func__, reg);
389         break;
390     }
391 }
392 
393 static int lm_i2c_event(I2CSlave *i2c, enum i2c_event event)
394 {
395     LM823KbdState *s = LM8323(i2c);
396 
397     switch (event) {
398     case I2C_START_RECV:
399     case I2C_START_SEND:
400         s->i2c_cycle = 0;
401         s->i2c_dir = (event == I2C_START_SEND);
402         break;
403 
404     default:
405         break;
406     }
407 
408     return 0;
409 }
410 
411 static uint8_t lm_i2c_rx(I2CSlave *i2c)
412 {
413     LM823KbdState *s = LM8323(i2c);
414 
415     return lm_kbd_read(s, s->reg, s->i2c_cycle ++);
416 }
417 
418 static int lm_i2c_tx(I2CSlave *i2c, uint8_t data)
419 {
420     LM823KbdState *s = LM8323(i2c);
421 
422     if (!s->i2c_cycle)
423         s->reg = data;
424     else
425         lm_kbd_write(s, s->reg, s->i2c_cycle - 1, data);
426     s->i2c_cycle ++;
427 
428     return 0;
429 }
430 
431 static int lm_kbd_post_load(void *opaque, int version_id)
432 {
433     LM823KbdState *s = opaque;
434 
435     lm_kbd_irq_update(s);
436     lm_kbd_gpio_update(s);
437 
438     return 0;
439 }
440 
441 static const VMStateDescription vmstate_lm_kbd = {
442     .name = "LM8323",
443     .version_id = 0,
444     .minimum_version_id = 0,
445     .post_load = lm_kbd_post_load,
446     .fields = (VMStateField[]) {
447         VMSTATE_I2C_SLAVE(parent_obj, LM823KbdState),
448         VMSTATE_UINT8(i2c_dir, LM823KbdState),
449         VMSTATE_UINT8(i2c_cycle, LM823KbdState),
450         VMSTATE_UINT8(reg, LM823KbdState),
451         VMSTATE_UINT8(config, LM823KbdState),
452         VMSTATE_UINT8(status, LM823KbdState),
453         VMSTATE_UINT8(acttime, LM823KbdState),
454         VMSTATE_UINT8(error, LM823KbdState),
455         VMSTATE_UINT8(clock, LM823KbdState),
456         VMSTATE_UINT16(gpio.pull, LM823KbdState),
457         VMSTATE_UINT16(gpio.mask, LM823KbdState),
458         VMSTATE_UINT16(gpio.dir, LM823KbdState),
459         VMSTATE_UINT16(gpio.level, LM823KbdState),
460         VMSTATE_UINT8(kbd.dbnctime, LM823KbdState),
461         VMSTATE_UINT8(kbd.size, LM823KbdState),
462         VMSTATE_UINT8(kbd.start, LM823KbdState),
463         VMSTATE_UINT8(kbd.len, LM823KbdState),
464         VMSTATE_BUFFER(kbd.fifo, LM823KbdState),
465         VMSTATE_UINT16_ARRAY(pwm.file, LM823KbdState, 256),
466         VMSTATE_UINT8(pwm.faddr, LM823KbdState),
467         VMSTATE_BUFFER(pwm.addr, LM823KbdState),
468         VMSTATE_TIMER_PTR_ARRAY(pwm.tm, LM823KbdState, 3),
469         VMSTATE_END_OF_LIST()
470     }
471 };
472 
473 
474 static void lm8323_realize(DeviceState *dev, Error **errp)
475 {
476     LM823KbdState *s = LM8323(dev);
477 
478     s->model = 0x8323;
479     s->pwm.tm[0] = timer_new_ns(QEMU_CLOCK_VIRTUAL, lm_kbd_pwm0_tick, s);
480     s->pwm.tm[1] = timer_new_ns(QEMU_CLOCK_VIRTUAL, lm_kbd_pwm1_tick, s);
481     s->pwm.tm[2] = timer_new_ns(QEMU_CLOCK_VIRTUAL, lm_kbd_pwm2_tick, s);
482     qdev_init_gpio_out(dev, &s->nirq, 1);
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->reset = lm_kbd_reset;
511     dc->realize = lm8323_realize;
512     k->event = lm_i2c_event;
513     k->recv = lm_i2c_rx;
514     k->send = lm_i2c_tx;
515     dc->vmsd = &vmstate_lm_kbd;
516 }
517 
518 static const TypeInfo lm8323_info = {
519     .name          = TYPE_LM8323,
520     .parent        = TYPE_I2C_SLAVE,
521     .instance_size = sizeof(LM823KbdState),
522     .class_init    = lm8323_class_init,
523 };
524 
525 static void lm832x_register_types(void)
526 {
527     type_register_static(&lm8323_info);
528 }
529 
530 type_init(lm832x_register_types)
531