xref: /openbmc/qemu/hw/input/lm832x.c (revision 869e9aec)
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/timer.h"
25 #include "ui/console.h"
26 
27 #define TYPE_LM8323 "lm8323"
28 #define LM8323(obj) OBJECT_CHECK(LM823KbdState, (obj), TYPE_LM8323)
29 
30 typedef struct {
31     I2CSlave parent_obj;
32 
33     uint8_t i2c_dir;
34     uint8_t i2c_cycle;
35     uint8_t reg;
36 
37     qemu_irq nirq;
38     uint16_t model;
39 
40     struct {
41         qemu_irq out[2];
42         int in[2][2];
43     } mux;
44 
45     uint8_t config;
46     uint8_t status;
47     uint8_t acttime;
48     uint8_t error;
49     uint8_t clock;
50 
51     struct {
52         uint16_t pull;
53         uint16_t mask;
54         uint16_t dir;
55         uint16_t level;
56         qemu_irq out[16];
57     } gpio;
58 
59     struct {
60         uint8_t dbnctime;
61         uint8_t size;
62         uint8_t start;
63         uint8_t len;
64         uint8_t fifo[16];
65     } kbd;
66 
67     struct {
68         uint16_t file[256];
69 	uint8_t faddr;
70         uint8_t addr[3];
71         QEMUTimer *tm[3];
72     } pwm;
73 } LM823KbdState;
74 
75 #define INT_KEYPAD		(1 << 0)
76 #define INT_ERROR		(1 << 3)
77 #define INT_NOINIT		(1 << 4)
78 #define INT_PWMEND(n)		(1 << (5 + n))
79 
80 #define ERR_BADPAR		(1 << 0)
81 #define ERR_CMDUNK		(1 << 1)
82 #define ERR_KEYOVR		(1 << 2)
83 #define ERR_FIFOOVR		(1 << 6)
84 
85 static void lm_kbd_irq_update(LM823KbdState *s)
86 {
87     qemu_set_irq(s->nirq, !s->status);
88 }
89 
90 static void lm_kbd_gpio_update(LM823KbdState *s)
91 {
92 }
93 
94 static void lm_kbd_reset(LM823KbdState *s)
95 {
96     s->config = 0x80;
97     s->status = INT_NOINIT;
98     s->acttime = 125;
99     s->kbd.dbnctime = 3;
100     s->kbd.size = 0x33;
101     s->clock = 0x08;
102 
103     lm_kbd_irq_update(s);
104     lm_kbd_gpio_update(s);
105 }
106 
107 static void lm_kbd_error(LM823KbdState *s, int err)
108 {
109     s->error |= err;
110     s->status |= INT_ERROR;
111     lm_kbd_irq_update(s);
112 }
113 
114 static void lm_kbd_pwm_tick(LM823KbdState *s, int line)
115 {
116 }
117 
118 static void lm_kbd_pwm_start(LM823KbdState *s, int line)
119 {
120     lm_kbd_pwm_tick(s, line);
121 }
122 
123 static void lm_kbd_pwm0_tick(void *opaque)
124 {
125     lm_kbd_pwm_tick(opaque, 0);
126 }
127 static void lm_kbd_pwm1_tick(void *opaque)
128 {
129     lm_kbd_pwm_tick(opaque, 1);
130 }
131 static void lm_kbd_pwm2_tick(void *opaque)
132 {
133     lm_kbd_pwm_tick(opaque, 2);
134 }
135 
136 enum {
137     LM832x_CMD_READ_ID		= 0x80, /* Read chip ID. */
138     LM832x_CMD_WRITE_CFG	= 0x81, /* Set configuration item. */
139     LM832x_CMD_READ_INT		= 0x82, /* Get interrupt status. */
140     LM832x_CMD_RESET		= 0x83, /* Reset, same as external one */
141     LM823x_CMD_WRITE_PULL_DOWN	= 0x84, /* Select GPIO pull-up/down. */
142     LM832x_CMD_WRITE_PORT_SEL	= 0x85, /* Select GPIO in/out. */
143     LM832x_CMD_WRITE_PORT_STATE	= 0x86, /* Set GPIO pull-up/down. */
144     LM832x_CMD_READ_PORT_SEL	= 0x87, /* Get GPIO in/out. */
145     LM832x_CMD_READ_PORT_STATE	= 0x88, /* Get GPIO pull-up/down. */
146     LM832x_CMD_READ_FIFO	= 0x89, /* Read byte from FIFO. */
147     LM832x_CMD_RPT_READ_FIFO	= 0x8a, /* Read FIFO (no increment). */
148     LM832x_CMD_SET_ACTIVE	= 0x8b, /* Set active time. */
149     LM832x_CMD_READ_ERROR	= 0x8c, /* Get error status. */
150     LM832x_CMD_READ_ROTATOR	= 0x8e, /* Read rotator status. */
151     LM832x_CMD_SET_DEBOUNCE	= 0x8f, /* Set debouncing time. */
152     LM832x_CMD_SET_KEY_SIZE	= 0x90, /* Set keypad size. */
153     LM832x_CMD_READ_KEY_SIZE	= 0x91, /* Get keypad size. */
154     LM832x_CMD_READ_CFG		= 0x92, /* Get configuration item. */
155     LM832x_CMD_WRITE_CLOCK	= 0x93, /* Set clock config. */
156     LM832x_CMD_READ_CLOCK	= 0x94, /* Get clock config. */
157     LM832x_CMD_PWM_WRITE	= 0x95, /* Write PWM script. */
158     LM832x_CMD_PWM_START	= 0x96, /* Start PWM engine. */
159     LM832x_CMD_PWM_STOP		= 0x97, /* Stop PWM engine. */
160     LM832x_GENERAL_ERROR	= 0xff, /* There was one error.
161                                            Previously was represented by -1
162                                            This is not a command */
163 };
164 
165 #define LM832x_MAX_KPX		8
166 #define LM832x_MAX_KPY		12
167 
168 static uint8_t lm_kbd_read(LM823KbdState *s, int reg, int byte)
169 {
170     int ret;
171 
172     switch (reg) {
173     case LM832x_CMD_READ_ID:
174         ret = 0x0400;
175         break;
176 
177     case LM832x_CMD_READ_INT:
178         ret = s->status;
179         if (!(s->status & INT_NOINIT)) {
180             s->status = 0;
181             lm_kbd_irq_update(s);
182         }
183         break;
184 
185     case LM832x_CMD_READ_PORT_SEL:
186         ret = s->gpio.dir;
187         break;
188     case LM832x_CMD_READ_PORT_STATE:
189         ret = s->gpio.mask;
190         break;
191 
192     case LM832x_CMD_READ_FIFO:
193         if (s->kbd.len <= 1)
194             return 0x00;
195 
196         /* Example response from the two commands after a INT_KEYPAD
197          * interrupt caused by the key 0x3c being pressed:
198          * RPT_READ_FIFO: 55 bc 00 4e ff 0a 50 08 00 29 d9 08 01 c9 01
199          *     READ_FIFO: bc 00 00 4e ff 0a 50 08 00 29 d9 08 01 c9 01
200          * RPT_READ_FIFO: bc 00 00 4e ff 0a 50 08 00 29 d9 08 01 c9 01
201          *
202          * 55 is the code of the key release event serviced in the previous
203          * interrupt handling.
204          *
205          * TODO: find out whether the FIFO is advanced a single character
206          * before reading every byte or the whole size of the FIFO at the
207          * last LM832x_CMD_READ_FIFO.  This affects LM832x_CMD_RPT_READ_FIFO
208          * output in cases where there are more than one event in the FIFO.
209          * Assume 0xbc and 0x3c events are in the FIFO:
210          * RPT_READ_FIFO: 55 bc 3c 00 4e ff 0a 50 08 00 29 d9 08 01 c9
211          *     READ_FIFO: bc 3c 00 00 4e ff 0a 50 08 00 29 d9 08 01 c9
212          * Does RPT_READ_FIFO now return 0xbc and 0x3c or only 0x3c?
213          */
214         s->kbd.start ++;
215         s->kbd.start &= sizeof(s->kbd.fifo) - 1;
216         s->kbd.len --;
217 
218         return s->kbd.fifo[s->kbd.start];
219     case LM832x_CMD_RPT_READ_FIFO:
220         if (byte >= s->kbd.len)
221             return 0x00;
222 
223         return s->kbd.fifo[(s->kbd.start + byte) & (sizeof(s->kbd.fifo) - 1)];
224 
225     case LM832x_CMD_READ_ERROR:
226         return s->error;
227 
228     case LM832x_CMD_READ_ROTATOR:
229         return 0;
230 
231     case LM832x_CMD_READ_KEY_SIZE:
232         return s->kbd.size;
233 
234     case LM832x_CMD_READ_CFG:
235         return s->config & 0xf;
236 
237     case LM832x_CMD_READ_CLOCK:
238         return (s->clock & 0xfc) | 2;
239 
240     default:
241         lm_kbd_error(s, ERR_CMDUNK);
242         fprintf(stderr, "%s: unknown command %02x\n", __FUNCTION__, reg);
243         return 0x00;
244     }
245 
246     return ret >> (byte << 3);
247 }
248 
249 static void lm_kbd_write(LM823KbdState *s, int reg, int byte, uint8_t value)
250 {
251     switch (reg) {
252     case LM832x_CMD_WRITE_CFG:
253         s->config = value;
254         /* This must be done whenever s->mux.in is updated (never).  */
255         if ((s->config >> 1) & 1)			/* MUX1EN */
256             qemu_set_irq(s->mux.out[0], s->mux.in[0][(s->config >> 0) & 1]);
257         if ((s->config >> 3) & 1)			/* MUX2EN */
258             qemu_set_irq(s->mux.out[0], s->mux.in[0][(s->config >> 2) & 1]);
259         /* TODO: check that this is issued only following the chip reset
260          * and not in the middle of operation and that it is followed by
261          * the GPIO ports re-resablishing through WRITE_PORT_SEL and
262          * WRITE_PORT_STATE (using a timer perhaps) and otherwise output
263          * warnings.  */
264         s->status = 0;
265         lm_kbd_irq_update(s);
266         s->kbd.len = 0;
267         s->kbd.start = 0;
268         s->reg = LM832x_GENERAL_ERROR;
269         break;
270 
271     case LM832x_CMD_RESET:
272         if (value == 0xaa)
273             lm_kbd_reset(s);
274         else
275             lm_kbd_error(s, ERR_BADPAR);
276         s->reg = LM832x_GENERAL_ERROR;
277         break;
278 
279     case LM823x_CMD_WRITE_PULL_DOWN:
280         if (!byte)
281             s->gpio.pull = value;
282         else {
283             s->gpio.pull |= value << 8;
284             lm_kbd_gpio_update(s);
285             s->reg = LM832x_GENERAL_ERROR;
286         }
287         break;
288     case LM832x_CMD_WRITE_PORT_SEL:
289         if (!byte)
290             s->gpio.dir = value;
291         else {
292             s->gpio.dir |= value << 8;
293             lm_kbd_gpio_update(s);
294             s->reg = LM832x_GENERAL_ERROR;
295         }
296         break;
297     case LM832x_CMD_WRITE_PORT_STATE:
298         if (!byte)
299             s->gpio.mask = value;
300         else {
301             s->gpio.mask |= value << 8;
302             lm_kbd_gpio_update(s);
303             s->reg = LM832x_GENERAL_ERROR;
304         }
305         break;
306 
307     case LM832x_CMD_SET_ACTIVE:
308         s->acttime = value;
309         s->reg = LM832x_GENERAL_ERROR;
310         break;
311 
312     case LM832x_CMD_SET_DEBOUNCE:
313         s->kbd.dbnctime = value;
314         s->reg = LM832x_GENERAL_ERROR;
315         if (!value)
316             lm_kbd_error(s, ERR_BADPAR);
317         break;
318 
319     case LM832x_CMD_SET_KEY_SIZE:
320         s->kbd.size = value;
321         s->reg = LM832x_GENERAL_ERROR;
322         if (
323                         (value & 0xf) < 3 || (value & 0xf) > LM832x_MAX_KPY ||
324                         (value >> 4) < 3 || (value >> 4) > LM832x_MAX_KPX)
325             lm_kbd_error(s, ERR_BADPAR);
326         break;
327 
328     case LM832x_CMD_WRITE_CLOCK:
329         s->clock = value;
330         s->reg = LM832x_GENERAL_ERROR;
331         if ((value & 3) && (value & 3) != 3) {
332             lm_kbd_error(s, ERR_BADPAR);
333             fprintf(stderr, "%s: invalid clock setting in RCPWM\n",
334                             __FUNCTION__);
335         }
336         /* TODO: Validate that the command is only issued once */
337         break;
338 
339     case LM832x_CMD_PWM_WRITE:
340         if (byte == 0) {
341             if (!(value & 3) || (value >> 2) > 59) {
342                 lm_kbd_error(s, ERR_BADPAR);
343                 s->reg = LM832x_GENERAL_ERROR;
344                 break;
345             }
346 
347             s->pwm.faddr = value;
348             s->pwm.file[s->pwm.faddr] = 0;
349         } else if (byte == 1) {
350             s->pwm.file[s->pwm.faddr] |= value << 8;
351         } else if (byte == 2) {
352             s->pwm.file[s->pwm.faddr] |= value << 0;
353             s->reg = LM832x_GENERAL_ERROR;
354         }
355         break;
356     case LM832x_CMD_PWM_START:
357         s->reg = LM832x_GENERAL_ERROR;
358         if (!(value & 3) || (value >> 2) > 59) {
359             lm_kbd_error(s, ERR_BADPAR);
360             break;
361         }
362 
363         s->pwm.addr[(value & 3) - 1] = value >> 2;
364         lm_kbd_pwm_start(s, (value & 3) - 1);
365         break;
366     case LM832x_CMD_PWM_STOP:
367         s->reg = LM832x_GENERAL_ERROR;
368         if (!(value & 3)) {
369             lm_kbd_error(s, ERR_BADPAR);
370             break;
371         }
372 
373         timer_del(s->pwm.tm[(value & 3) - 1]);
374         break;
375 
376     case LM832x_GENERAL_ERROR:
377         lm_kbd_error(s, ERR_BADPAR);
378         break;
379     default:
380         lm_kbd_error(s, ERR_CMDUNK);
381         fprintf(stderr, "%s: unknown command %02x\n", __FUNCTION__, reg);
382         break;
383     }
384 }
385 
386 static int lm_i2c_event(I2CSlave *i2c, enum i2c_event event)
387 {
388     LM823KbdState *s = LM8323(i2c);
389 
390     switch (event) {
391     case I2C_START_RECV:
392     case I2C_START_SEND:
393         s->i2c_cycle = 0;
394         s->i2c_dir = (event == I2C_START_SEND);
395         break;
396 
397     default:
398         break;
399     }
400 
401     return 0;
402 }
403 
404 static int lm_i2c_rx(I2CSlave *i2c)
405 {
406     LM823KbdState *s = LM8323(i2c);
407 
408     return lm_kbd_read(s, s->reg, s->i2c_cycle ++);
409 }
410 
411 static int lm_i2c_tx(I2CSlave *i2c, uint8_t data)
412 {
413     LM823KbdState *s = LM8323(i2c);
414 
415     if (!s->i2c_cycle)
416         s->reg = data;
417     else
418         lm_kbd_write(s, s->reg, s->i2c_cycle - 1, data);
419     s->i2c_cycle ++;
420 
421     return 0;
422 }
423 
424 static int lm_kbd_post_load(void *opaque, int version_id)
425 {
426     LM823KbdState *s = opaque;
427 
428     lm_kbd_irq_update(s);
429     lm_kbd_gpio_update(s);
430 
431     return 0;
432 }
433 
434 static const VMStateDescription vmstate_lm_kbd = {
435     .name = "LM8323",
436     .version_id = 0,
437     .minimum_version_id = 0,
438     .post_load = lm_kbd_post_load,
439     .fields = (VMStateField[]) {
440         VMSTATE_I2C_SLAVE(parent_obj, LM823KbdState),
441         VMSTATE_UINT8(i2c_dir, LM823KbdState),
442         VMSTATE_UINT8(i2c_cycle, LM823KbdState),
443         VMSTATE_UINT8(reg, LM823KbdState),
444         VMSTATE_UINT8(config, LM823KbdState),
445         VMSTATE_UINT8(status, LM823KbdState),
446         VMSTATE_UINT8(acttime, LM823KbdState),
447         VMSTATE_UINT8(error, LM823KbdState),
448         VMSTATE_UINT8(clock, LM823KbdState),
449         VMSTATE_UINT16(gpio.pull, LM823KbdState),
450         VMSTATE_UINT16(gpio.mask, LM823KbdState),
451         VMSTATE_UINT16(gpio.dir, LM823KbdState),
452         VMSTATE_UINT16(gpio.level, LM823KbdState),
453         VMSTATE_UINT8(kbd.dbnctime, LM823KbdState),
454         VMSTATE_UINT8(kbd.size, LM823KbdState),
455         VMSTATE_UINT8(kbd.start, LM823KbdState),
456         VMSTATE_UINT8(kbd.len, LM823KbdState),
457         VMSTATE_BUFFER(kbd.fifo, LM823KbdState),
458         VMSTATE_UINT16_ARRAY(pwm.file, LM823KbdState, 256),
459         VMSTATE_UINT8(pwm.faddr, LM823KbdState),
460         VMSTATE_BUFFER(pwm.addr, LM823KbdState),
461         VMSTATE_TIMER_PTR_ARRAY(pwm.tm, LM823KbdState, 3),
462         VMSTATE_END_OF_LIST()
463     }
464 };
465 
466 
467 static int lm8323_init(I2CSlave *i2c)
468 {
469     LM823KbdState *s = LM8323(i2c);
470 
471     s->model = 0x8323;
472     s->pwm.tm[0] = timer_new_ns(QEMU_CLOCK_VIRTUAL, lm_kbd_pwm0_tick, s);
473     s->pwm.tm[1] = timer_new_ns(QEMU_CLOCK_VIRTUAL, lm_kbd_pwm1_tick, s);
474     s->pwm.tm[2] = timer_new_ns(QEMU_CLOCK_VIRTUAL, lm_kbd_pwm2_tick, s);
475     qdev_init_gpio_out(DEVICE(i2c), &s->nirq, 1);
476 
477     lm_kbd_reset(s);
478 
479     qemu_register_reset((void *) lm_kbd_reset, s);
480     return 0;
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     k->init = lm8323_init;
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