xref: /openbmc/qemu/hw/input/lm832x.c (revision e6e03dcf)
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 
29 #define TYPE_LM8323 "lm8323"
30 #define LM8323(obj) OBJECT_CHECK(LM823KbdState, (obj), TYPE_LM8323)
31 
32 typedef struct {
33     I2CSlave parent_obj;
34 
35     uint8_t i2c_dir;
36     uint8_t i2c_cycle;
37     uint8_t reg;
38 
39     qemu_irq nirq;
40     uint16_t model;
41 
42     struct {
43         qemu_irq out[2];
44         int in[2][2];
45     } mux;
46 
47     uint8_t config;
48     uint8_t status;
49     uint8_t acttime;
50     uint8_t error;
51     uint8_t clock;
52 
53     struct {
54         uint16_t pull;
55         uint16_t mask;
56         uint16_t dir;
57         uint16_t level;
58         qemu_irq out[16];
59     } gpio;
60 
61     struct {
62         uint8_t dbnctime;
63         uint8_t size;
64         uint8_t start;
65         uint8_t len;
66         uint8_t fifo[16];
67     } kbd;
68 
69     struct {
70         uint16_t file[256];
71         uint8_t faddr;
72         uint8_t addr[3];
73         QEMUTimer *tm[3];
74     } pwm;
75 } LM823KbdState;
76 
77 #define INT_KEYPAD		(1 << 0)
78 #define INT_ERROR		(1 << 3)
79 #define INT_NOINIT		(1 << 4)
80 #define INT_PWMEND(n)		(1 << (5 + n))
81 
82 #define ERR_BADPAR		(1 << 0)
83 #define ERR_CMDUNK		(1 << 1)
84 #define ERR_KEYOVR		(1 << 2)
85 #define ERR_FIFOOVR		(1 << 6)
86 
87 static void lm_kbd_irq_update(LM823KbdState *s)
88 {
89     qemu_set_irq(s->nirq, !s->status);
90 }
91 
92 static void lm_kbd_gpio_update(LM823KbdState *s)
93 {
94 }
95 
96 static void lm_kbd_reset(DeviceState *dev)
97 {
98     LM823KbdState *s = LM8323(dev);
99 
100     s->config = 0x80;
101     s->status = INT_NOINIT;
102     s->acttime = 125;
103     s->kbd.dbnctime = 3;
104     s->kbd.size = 0x33;
105     s->clock = 0x08;
106 
107     lm_kbd_irq_update(s);
108     lm_kbd_gpio_update(s);
109 }
110 
111 static void lm_kbd_error(LM823KbdState *s, int err)
112 {
113     s->error |= err;
114     s->status |= INT_ERROR;
115     lm_kbd_irq_update(s);
116 }
117 
118 static void lm_kbd_pwm_tick(LM823KbdState *s, int line)
119 {
120 }
121 
122 static void lm_kbd_pwm_start(LM823KbdState *s, int line)
123 {
124     lm_kbd_pwm_tick(s, line);
125 }
126 
127 static void lm_kbd_pwm0_tick(void *opaque)
128 {
129     lm_kbd_pwm_tick(opaque, 0);
130 }
131 static void lm_kbd_pwm1_tick(void *opaque)
132 {
133     lm_kbd_pwm_tick(opaque, 1);
134 }
135 static void lm_kbd_pwm2_tick(void *opaque)
136 {
137     lm_kbd_pwm_tick(opaque, 2);
138 }
139 
140 enum {
141     LM832x_CMD_READ_ID		= 0x80, /* Read chip ID. */
142     LM832x_CMD_WRITE_CFG	= 0x81, /* Set configuration item. */
143     LM832x_CMD_READ_INT		= 0x82, /* Get interrupt status. */
144     LM832x_CMD_RESET		= 0x83, /* Reset, same as external one */
145     LM823x_CMD_WRITE_PULL_DOWN	= 0x84, /* Select GPIO pull-up/down. */
146     LM832x_CMD_WRITE_PORT_SEL	= 0x85, /* Select GPIO in/out. */
147     LM832x_CMD_WRITE_PORT_STATE	= 0x86, /* Set GPIO pull-up/down. */
148     LM832x_CMD_READ_PORT_SEL	= 0x87, /* Get GPIO in/out. */
149     LM832x_CMD_READ_PORT_STATE	= 0x88, /* Get GPIO pull-up/down. */
150     LM832x_CMD_READ_FIFO	= 0x89, /* Read byte from FIFO. */
151     LM832x_CMD_RPT_READ_FIFO	= 0x8a, /* Read FIFO (no increment). */
152     LM832x_CMD_SET_ACTIVE	= 0x8b, /* Set active time. */
153     LM832x_CMD_READ_ERROR	= 0x8c, /* Get error status. */
154     LM832x_CMD_READ_ROTATOR	= 0x8e, /* Read rotator status. */
155     LM832x_CMD_SET_DEBOUNCE	= 0x8f, /* Set debouncing time. */
156     LM832x_CMD_SET_KEY_SIZE	= 0x90, /* Set keypad size. */
157     LM832x_CMD_READ_KEY_SIZE	= 0x91, /* Get keypad size. */
158     LM832x_CMD_READ_CFG		= 0x92, /* Get configuration item. */
159     LM832x_CMD_WRITE_CLOCK	= 0x93, /* Set clock config. */
160     LM832x_CMD_READ_CLOCK	= 0x94, /* Get clock config. */
161     LM832x_CMD_PWM_WRITE	= 0x95, /* Write PWM script. */
162     LM832x_CMD_PWM_START	= 0x96, /* Start PWM engine. */
163     LM832x_CMD_PWM_STOP		= 0x97, /* Stop PWM engine. */
164     LM832x_GENERAL_ERROR	= 0xff, /* There was one error.
165                                            Previously was represented by -1
166                                            This is not a command */
167 };
168 
169 #define LM832x_MAX_KPX		8
170 #define LM832x_MAX_KPY		12
171 
172 static uint8_t lm_kbd_read(LM823KbdState *s, int reg, int byte)
173 {
174     int ret;
175 
176     switch (reg) {
177     case LM832x_CMD_READ_ID:
178         ret = 0x0400;
179         break;
180 
181     case LM832x_CMD_READ_INT:
182         ret = s->status;
183         if (!(s->status & INT_NOINIT)) {
184             s->status = 0;
185             lm_kbd_irq_update(s);
186         }
187         break;
188 
189     case LM832x_CMD_READ_PORT_SEL:
190         ret = s->gpio.dir;
191         break;
192     case LM832x_CMD_READ_PORT_STATE:
193         ret = s->gpio.mask;
194         break;
195 
196     case LM832x_CMD_READ_FIFO:
197         if (s->kbd.len <= 1)
198             return 0x00;
199 
200         /* Example response from the two commands after a INT_KEYPAD
201          * interrupt caused by the key 0x3c being pressed:
202          * RPT_READ_FIFO: 55 bc 00 4e ff 0a 50 08 00 29 d9 08 01 c9 01
203          *     READ_FIFO: bc 00 00 4e ff 0a 50 08 00 29 d9 08 01 c9 01
204          * RPT_READ_FIFO: bc 00 00 4e ff 0a 50 08 00 29 d9 08 01 c9 01
205          *
206          * 55 is the code of the key release event serviced in the previous
207          * interrupt handling.
208          *
209          * TODO: find out whether the FIFO is advanced a single character
210          * before reading every byte or the whole size of the FIFO at the
211          * last LM832x_CMD_READ_FIFO.  This affects LM832x_CMD_RPT_READ_FIFO
212          * output in cases where there are more than one event in the FIFO.
213          * Assume 0xbc and 0x3c events are in the FIFO:
214          * RPT_READ_FIFO: 55 bc 3c 00 4e ff 0a 50 08 00 29 d9 08 01 c9
215          *     READ_FIFO: bc 3c 00 00 4e ff 0a 50 08 00 29 d9 08 01 c9
216          * Does RPT_READ_FIFO now return 0xbc and 0x3c or only 0x3c?
217          */
218         s->kbd.start ++;
219         s->kbd.start &= sizeof(s->kbd.fifo) - 1;
220         s->kbd.len --;
221 
222         return s->kbd.fifo[s->kbd.start];
223     case LM832x_CMD_RPT_READ_FIFO:
224         if (byte >= s->kbd.len)
225             return 0x00;
226 
227         return s->kbd.fifo[(s->kbd.start + byte) & (sizeof(s->kbd.fifo) - 1)];
228 
229     case LM832x_CMD_READ_ERROR:
230         return s->error;
231 
232     case LM832x_CMD_READ_ROTATOR:
233         return 0;
234 
235     case LM832x_CMD_READ_KEY_SIZE:
236         return s->kbd.size;
237 
238     case LM832x_CMD_READ_CFG:
239         return s->config & 0xf;
240 
241     case LM832x_CMD_READ_CLOCK:
242         return (s->clock & 0xfc) | 2;
243 
244     default:
245         lm_kbd_error(s, ERR_CMDUNK);
246         fprintf(stderr, "%s: unknown command %02x\n", __func__, reg);
247         return 0x00;
248     }
249 
250     return ret >> (byte << 3);
251 }
252 
253 static void lm_kbd_write(LM823KbdState *s, int reg, int byte, uint8_t value)
254 {
255     switch (reg) {
256     case LM832x_CMD_WRITE_CFG:
257         s->config = value;
258         /* This must be done whenever s->mux.in is updated (never).  */
259         if ((s->config >> 1) & 1)			/* MUX1EN */
260             qemu_set_irq(s->mux.out[0], s->mux.in[0][(s->config >> 0) & 1]);
261         if ((s->config >> 3) & 1)			/* MUX2EN */
262             qemu_set_irq(s->mux.out[0], s->mux.in[0][(s->config >> 2) & 1]);
263         /* TODO: check that this is issued only following the chip reset
264          * and not in the middle of operation and that it is followed by
265          * the GPIO ports re-resablishing through WRITE_PORT_SEL and
266          * WRITE_PORT_STATE (using a timer perhaps) and otherwise output
267          * warnings.  */
268         s->status = 0;
269         lm_kbd_irq_update(s);
270         s->kbd.len = 0;
271         s->kbd.start = 0;
272         s->reg = LM832x_GENERAL_ERROR;
273         break;
274 
275     case LM832x_CMD_RESET:
276         if (value == 0xaa)
277             lm_kbd_reset(DEVICE(s));
278         else
279             lm_kbd_error(s, ERR_BADPAR);
280         s->reg = LM832x_GENERAL_ERROR;
281         break;
282 
283     case LM823x_CMD_WRITE_PULL_DOWN:
284         if (!byte)
285             s->gpio.pull = value;
286         else {
287             s->gpio.pull |= value << 8;
288             lm_kbd_gpio_update(s);
289             s->reg = LM832x_GENERAL_ERROR;
290         }
291         break;
292     case LM832x_CMD_WRITE_PORT_SEL:
293         if (!byte)
294             s->gpio.dir = value;
295         else {
296             s->gpio.dir |= value << 8;
297             lm_kbd_gpio_update(s);
298             s->reg = LM832x_GENERAL_ERROR;
299         }
300         break;
301     case LM832x_CMD_WRITE_PORT_STATE:
302         if (!byte)
303             s->gpio.mask = value;
304         else {
305             s->gpio.mask |= value << 8;
306             lm_kbd_gpio_update(s);
307             s->reg = LM832x_GENERAL_ERROR;
308         }
309         break;
310 
311     case LM832x_CMD_SET_ACTIVE:
312         s->acttime = value;
313         s->reg = LM832x_GENERAL_ERROR;
314         break;
315 
316     case LM832x_CMD_SET_DEBOUNCE:
317         s->kbd.dbnctime = value;
318         s->reg = LM832x_GENERAL_ERROR;
319         if (!value)
320             lm_kbd_error(s, ERR_BADPAR);
321         break;
322 
323     case LM832x_CMD_SET_KEY_SIZE:
324         s->kbd.size = value;
325         s->reg = LM832x_GENERAL_ERROR;
326         if (
327                         (value & 0xf) < 3 || (value & 0xf) > LM832x_MAX_KPY ||
328                         (value >> 4) < 3 || (value >> 4) > LM832x_MAX_KPX)
329             lm_kbd_error(s, ERR_BADPAR);
330         break;
331 
332     case LM832x_CMD_WRITE_CLOCK:
333         s->clock = value;
334         s->reg = LM832x_GENERAL_ERROR;
335         if ((value & 3) && (value & 3) != 3) {
336             lm_kbd_error(s, ERR_BADPAR);
337             fprintf(stderr, "%s: invalid clock setting in RCPWM\n",
338                             __func__);
339         }
340         /* TODO: Validate that the command is only issued once */
341         break;
342 
343     case LM832x_CMD_PWM_WRITE:
344         if (byte == 0) {
345             if (!(value & 3) || (value >> 2) > 59) {
346                 lm_kbd_error(s, ERR_BADPAR);
347                 s->reg = LM832x_GENERAL_ERROR;
348                 break;
349             }
350 
351             s->pwm.faddr = value;
352             s->pwm.file[s->pwm.faddr] = 0;
353         } else if (byte == 1) {
354             s->pwm.file[s->pwm.faddr] |= value << 8;
355         } else if (byte == 2) {
356             s->pwm.file[s->pwm.faddr] |= value << 0;
357             s->reg = LM832x_GENERAL_ERROR;
358         }
359         break;
360     case LM832x_CMD_PWM_START:
361         s->reg = LM832x_GENERAL_ERROR;
362         if (!(value & 3) || (value >> 2) > 59) {
363             lm_kbd_error(s, ERR_BADPAR);
364             break;
365         }
366 
367         s->pwm.addr[(value & 3) - 1] = value >> 2;
368         lm_kbd_pwm_start(s, (value & 3) - 1);
369         break;
370     case LM832x_CMD_PWM_STOP:
371         s->reg = LM832x_GENERAL_ERROR;
372         if (!(value & 3)) {
373             lm_kbd_error(s, ERR_BADPAR);
374             break;
375         }
376 
377         timer_del(s->pwm.tm[(value & 3) - 1]);
378         break;
379 
380     case LM832x_GENERAL_ERROR:
381         lm_kbd_error(s, ERR_BADPAR);
382         break;
383     default:
384         lm_kbd_error(s, ERR_CMDUNK);
385         fprintf(stderr, "%s: unknown command %02x\n", __func__, reg);
386         break;
387     }
388 }
389 
390 static int lm_i2c_event(I2CSlave *i2c, enum i2c_event event)
391 {
392     LM823KbdState *s = LM8323(i2c);
393 
394     switch (event) {
395     case I2C_START_RECV:
396     case I2C_START_SEND:
397         s->i2c_cycle = 0;
398         s->i2c_dir = (event == I2C_START_SEND);
399         break;
400 
401     default:
402         break;
403     }
404 
405     return 0;
406 }
407 
408 static uint8_t lm_i2c_rx(I2CSlave *i2c)
409 {
410     LM823KbdState *s = LM8323(i2c);
411 
412     return lm_kbd_read(s, s->reg, s->i2c_cycle ++);
413 }
414 
415 static int lm_i2c_tx(I2CSlave *i2c, uint8_t data)
416 {
417     LM823KbdState *s = LM8323(i2c);
418 
419     if (!s->i2c_cycle)
420         s->reg = data;
421     else
422         lm_kbd_write(s, s->reg, s->i2c_cycle - 1, data);
423     s->i2c_cycle ++;
424 
425     return 0;
426 }
427 
428 static int lm_kbd_post_load(void *opaque, int version_id)
429 {
430     LM823KbdState *s = opaque;
431 
432     lm_kbd_irq_update(s);
433     lm_kbd_gpio_update(s);
434 
435     return 0;
436 }
437 
438 static const VMStateDescription vmstate_lm_kbd = {
439     .name = "LM8323",
440     .version_id = 0,
441     .minimum_version_id = 0,
442     .post_load = lm_kbd_post_load,
443     .fields = (VMStateField[]) {
444         VMSTATE_I2C_SLAVE(parent_obj, LM823KbdState),
445         VMSTATE_UINT8(i2c_dir, LM823KbdState),
446         VMSTATE_UINT8(i2c_cycle, LM823KbdState),
447         VMSTATE_UINT8(reg, LM823KbdState),
448         VMSTATE_UINT8(config, LM823KbdState),
449         VMSTATE_UINT8(status, LM823KbdState),
450         VMSTATE_UINT8(acttime, LM823KbdState),
451         VMSTATE_UINT8(error, LM823KbdState),
452         VMSTATE_UINT8(clock, LM823KbdState),
453         VMSTATE_UINT16(gpio.pull, LM823KbdState),
454         VMSTATE_UINT16(gpio.mask, LM823KbdState),
455         VMSTATE_UINT16(gpio.dir, LM823KbdState),
456         VMSTATE_UINT16(gpio.level, LM823KbdState),
457         VMSTATE_UINT8(kbd.dbnctime, LM823KbdState),
458         VMSTATE_UINT8(kbd.size, LM823KbdState),
459         VMSTATE_UINT8(kbd.start, LM823KbdState),
460         VMSTATE_UINT8(kbd.len, LM823KbdState),
461         VMSTATE_BUFFER(kbd.fifo, LM823KbdState),
462         VMSTATE_UINT16_ARRAY(pwm.file, LM823KbdState, 256),
463         VMSTATE_UINT8(pwm.faddr, LM823KbdState),
464         VMSTATE_BUFFER(pwm.addr, LM823KbdState),
465         VMSTATE_TIMER_PTR_ARRAY(pwm.tm, LM823KbdState, 3),
466         VMSTATE_END_OF_LIST()
467     }
468 };
469 
470 
471 static void lm8323_realize(DeviceState *dev, Error **errp)
472 {
473     LM823KbdState *s = LM8323(dev);
474 
475     s->model = 0x8323;
476     s->pwm.tm[0] = timer_new_ns(QEMU_CLOCK_VIRTUAL, lm_kbd_pwm0_tick, s);
477     s->pwm.tm[1] = timer_new_ns(QEMU_CLOCK_VIRTUAL, lm_kbd_pwm1_tick, s);
478     s->pwm.tm[2] = timer_new_ns(QEMU_CLOCK_VIRTUAL, lm_kbd_pwm2_tick, s);
479     qdev_init_gpio_out(dev, &s->nirq, 1);
480 }
481 
482 void lm832x_key_event(DeviceState *dev, int key, int state)
483 {
484     LM823KbdState *s = LM8323(dev);
485 
486     if ((s->status & INT_ERROR) && (s->error & ERR_FIFOOVR))
487         return;
488 
489     if (s->kbd.len >= sizeof(s->kbd.fifo)) {
490         lm_kbd_error(s, ERR_FIFOOVR);
491         return;
492     }
493 
494     s->kbd.fifo[(s->kbd.start + s->kbd.len ++) & (sizeof(s->kbd.fifo) - 1)] =
495             key | (state << 7);
496 
497     /* We never set ERR_KEYOVR because we support multiple keys fine.  */
498     s->status |= INT_KEYPAD;
499     lm_kbd_irq_update(s);
500 }
501 
502 static void lm8323_class_init(ObjectClass *klass, void *data)
503 {
504     DeviceClass *dc = DEVICE_CLASS(klass);
505     I2CSlaveClass *k = I2C_SLAVE_CLASS(klass);
506 
507     dc->reset = lm_kbd_reset;
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