xref: /openbmc/qemu/hw/input/lm832x.c (revision ddbb0d09)
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 "hw/hw.h"
22 #include "hw/i2c/i2c.h"
23 #include "qemu/timer.h"
24 #include "ui/console.h"
25 
26 #define TYPE_LM8323 "lm8323"
27 #define LM8323(obj) OBJECT_CHECK(LM823KbdState, (obj), TYPE_LM8323)
28 
29 typedef struct {
30     I2CSlave parent_obj;
31 
32     uint8_t i2c_dir;
33     uint8_t i2c_cycle;
34     uint8_t reg;
35 
36     qemu_irq nirq;
37     uint16_t model;
38 
39     struct {
40         qemu_irq out[2];
41         int in[2][2];
42     } mux;
43 
44     uint8_t config;
45     uint8_t status;
46     uint8_t acttime;
47     uint8_t error;
48     uint8_t clock;
49 
50     struct {
51         uint16_t pull;
52         uint16_t mask;
53         uint16_t dir;
54         uint16_t level;
55         qemu_irq out[16];
56     } gpio;
57 
58     struct {
59         uint8_t dbnctime;
60         uint8_t size;
61         uint8_t start;
62         uint8_t len;
63         uint8_t fifo[16];
64     } kbd;
65 
66     struct {
67         uint16_t file[256];
68 	uint8_t faddr;
69         uint8_t addr[3];
70         QEMUTimer *tm[3];
71     } pwm;
72 } LM823KbdState;
73 
74 #define INT_KEYPAD		(1 << 0)
75 #define INT_ERROR		(1 << 3)
76 #define INT_NOINIT		(1 << 4)
77 #define INT_PWMEND(n)		(1 << (5 + n))
78 
79 #define ERR_BADPAR		(1 << 0)
80 #define ERR_CMDUNK		(1 << 1)
81 #define ERR_KEYOVR		(1 << 2)
82 #define ERR_FIFOOVR		(1 << 6)
83 
84 static void lm_kbd_irq_update(LM823KbdState *s)
85 {
86     qemu_set_irq(s->nirq, !s->status);
87 }
88 
89 static void lm_kbd_gpio_update(LM823KbdState *s)
90 {
91 }
92 
93 static void lm_kbd_reset(LM823KbdState *s)
94 {
95     s->config = 0x80;
96     s->status = INT_NOINIT;
97     s->acttime = 125;
98     s->kbd.dbnctime = 3;
99     s->kbd.size = 0x33;
100     s->clock = 0x08;
101 
102     lm_kbd_irq_update(s);
103     lm_kbd_gpio_update(s);
104 }
105 
106 static void lm_kbd_error(LM823KbdState *s, int err)
107 {
108     s->error |= err;
109     s->status |= INT_ERROR;
110     lm_kbd_irq_update(s);
111 }
112 
113 static void lm_kbd_pwm_tick(LM823KbdState *s, int line)
114 {
115 }
116 
117 static void lm_kbd_pwm_start(LM823KbdState *s, int line)
118 {
119     lm_kbd_pwm_tick(s, line);
120 }
121 
122 static void lm_kbd_pwm0_tick(void *opaque)
123 {
124     lm_kbd_pwm_tick(opaque, 0);
125 }
126 static void lm_kbd_pwm1_tick(void *opaque)
127 {
128     lm_kbd_pwm_tick(opaque, 1);
129 }
130 static void lm_kbd_pwm2_tick(void *opaque)
131 {
132     lm_kbd_pwm_tick(opaque, 2);
133 }
134 
135 enum {
136     LM832x_CMD_READ_ID		= 0x80, /* Read chip ID. */
137     LM832x_CMD_WRITE_CFG	= 0x81, /* Set configuration item. */
138     LM832x_CMD_READ_INT		= 0x82, /* Get interrupt status. */
139     LM832x_CMD_RESET		= 0x83, /* Reset, same as external one */
140     LM823x_CMD_WRITE_PULL_DOWN	= 0x84, /* Select GPIO pull-up/down. */
141     LM832x_CMD_WRITE_PORT_SEL	= 0x85, /* Select GPIO in/out. */
142     LM832x_CMD_WRITE_PORT_STATE	= 0x86, /* Set GPIO pull-up/down. */
143     LM832x_CMD_READ_PORT_SEL	= 0x87, /* Get GPIO in/out. */
144     LM832x_CMD_READ_PORT_STATE	= 0x88, /* Get GPIO pull-up/down. */
145     LM832x_CMD_READ_FIFO	= 0x89, /* Read byte from FIFO. */
146     LM832x_CMD_RPT_READ_FIFO	= 0x8a, /* Read FIFO (no increment). */
147     LM832x_CMD_SET_ACTIVE	= 0x8b, /* Set active time. */
148     LM832x_CMD_READ_ERROR	= 0x8c, /* Get error status. */
149     LM832x_CMD_READ_ROTATOR	= 0x8e, /* Read rotator status. */
150     LM832x_CMD_SET_DEBOUNCE	= 0x8f, /* Set debouncing time. */
151     LM832x_CMD_SET_KEY_SIZE	= 0x90, /* Set keypad size. */
152     LM832x_CMD_READ_KEY_SIZE	= 0x91, /* Get keypad size. */
153     LM832x_CMD_READ_CFG		= 0x92, /* Get configuration item. */
154     LM832x_CMD_WRITE_CLOCK	= 0x93, /* Set clock config. */
155     LM832x_CMD_READ_CLOCK	= 0x94, /* Get clock config. */
156     LM832x_CMD_PWM_WRITE	= 0x95, /* Write PWM script. */
157     LM832x_CMD_PWM_START	= 0x96, /* Start PWM engine. */
158     LM832x_CMD_PWM_STOP		= 0x97, /* Stop PWM engine. */
159     LM832x_GENERAL_ERROR	= 0xff, /* There was one error.
160                                            Previously was represented by -1
161                                            This is not a command */
162 };
163 
164 #define LM832x_MAX_KPX		8
165 #define LM832x_MAX_KPY		12
166 
167 static uint8_t lm_kbd_read(LM823KbdState *s, int reg, int byte)
168 {
169     int ret;
170 
171     switch (reg) {
172     case LM832x_CMD_READ_ID:
173         ret = 0x0400;
174         break;
175 
176     case LM832x_CMD_READ_INT:
177         ret = s->status;
178         if (!(s->status & INT_NOINIT)) {
179             s->status = 0;
180             lm_kbd_irq_update(s);
181         }
182         break;
183 
184     case LM832x_CMD_READ_PORT_SEL:
185         ret = s->gpio.dir;
186         break;
187     case LM832x_CMD_READ_PORT_STATE:
188         ret = s->gpio.mask;
189         break;
190 
191     case LM832x_CMD_READ_FIFO:
192         if (s->kbd.len <= 1)
193             return 0x00;
194 
195         /* Example response from the two commands after a INT_KEYPAD
196          * interrupt caused by the key 0x3c being pressed:
197          * RPT_READ_FIFO: 55 bc 00 4e ff 0a 50 08 00 29 d9 08 01 c9 01
198          *     READ_FIFO: bc 00 00 4e ff 0a 50 08 00 29 d9 08 01 c9 01
199          * RPT_READ_FIFO: bc 00 00 4e ff 0a 50 08 00 29 d9 08 01 c9 01
200          *
201          * 55 is the code of the key release event serviced in the previous
202          * interrupt handling.
203          *
204          * TODO: find out whether the FIFO is advanced a single character
205          * before reading every byte or the whole size of the FIFO at the
206          * last LM832x_CMD_READ_FIFO.  This affects LM832x_CMD_RPT_READ_FIFO
207          * output in cases where there are more than one event in the FIFO.
208          * Assume 0xbc and 0x3c events are in the FIFO:
209          * RPT_READ_FIFO: 55 bc 3c 00 4e ff 0a 50 08 00 29 d9 08 01 c9
210          *     READ_FIFO: bc 3c 00 00 4e ff 0a 50 08 00 29 d9 08 01 c9
211          * Does RPT_READ_FIFO now return 0xbc and 0x3c or only 0x3c?
212          */
213         s->kbd.start ++;
214         s->kbd.start &= sizeof(s->kbd.fifo) - 1;
215         s->kbd.len --;
216 
217         return s->kbd.fifo[s->kbd.start];
218     case LM832x_CMD_RPT_READ_FIFO:
219         if (byte >= s->kbd.len)
220             return 0x00;
221 
222         return s->kbd.fifo[(s->kbd.start + byte) & (sizeof(s->kbd.fifo) - 1)];
223 
224     case LM832x_CMD_READ_ERROR:
225         return s->error;
226 
227     case LM832x_CMD_READ_ROTATOR:
228         return 0;
229 
230     case LM832x_CMD_READ_KEY_SIZE:
231         return s->kbd.size;
232 
233     case LM832x_CMD_READ_CFG:
234         return s->config & 0xf;
235 
236     case LM832x_CMD_READ_CLOCK:
237         return (s->clock & 0xfc) | 2;
238 
239     default:
240         lm_kbd_error(s, ERR_CMDUNK);
241         fprintf(stderr, "%s: unknown command %02x\n", __FUNCTION__, reg);
242         return 0x00;
243     }
244 
245     return ret >> (byte << 3);
246 }
247 
248 static void lm_kbd_write(LM823KbdState *s, int reg, int byte, uint8_t value)
249 {
250     switch (reg) {
251     case LM832x_CMD_WRITE_CFG:
252         s->config = value;
253         /* This must be done whenever s->mux.in is updated (never).  */
254         if ((s->config >> 1) & 1)			/* MUX1EN */
255             qemu_set_irq(s->mux.out[0], s->mux.in[0][(s->config >> 0) & 1]);
256         if ((s->config >> 3) & 1)			/* MUX2EN */
257             qemu_set_irq(s->mux.out[0], s->mux.in[0][(s->config >> 2) & 1]);
258         /* TODO: check that this is issued only following the chip reset
259          * and not in the middle of operation and that it is followed by
260          * the GPIO ports re-resablishing through WRITE_PORT_SEL and
261          * WRITE_PORT_STATE (using a timer perhaps) and otherwise output
262          * warnings.  */
263         s->status = 0;
264         lm_kbd_irq_update(s);
265         s->kbd.len = 0;
266         s->kbd.start = 0;
267         s->reg = LM832x_GENERAL_ERROR;
268         break;
269 
270     case LM832x_CMD_RESET:
271         if (value == 0xaa)
272             lm_kbd_reset(s);
273         else
274             lm_kbd_error(s, ERR_BADPAR);
275         s->reg = LM832x_GENERAL_ERROR;
276         break;
277 
278     case LM823x_CMD_WRITE_PULL_DOWN:
279         if (!byte)
280             s->gpio.pull = value;
281         else {
282             s->gpio.pull |= value << 8;
283             lm_kbd_gpio_update(s);
284             s->reg = LM832x_GENERAL_ERROR;
285         }
286         break;
287     case LM832x_CMD_WRITE_PORT_SEL:
288         if (!byte)
289             s->gpio.dir = value;
290         else {
291             s->gpio.dir |= value << 8;
292             lm_kbd_gpio_update(s);
293             s->reg = LM832x_GENERAL_ERROR;
294         }
295         break;
296     case LM832x_CMD_WRITE_PORT_STATE:
297         if (!byte)
298             s->gpio.mask = value;
299         else {
300             s->gpio.mask |= value << 8;
301             lm_kbd_gpio_update(s);
302             s->reg = LM832x_GENERAL_ERROR;
303         }
304         break;
305 
306     case LM832x_CMD_SET_ACTIVE:
307         s->acttime = value;
308         s->reg = LM832x_GENERAL_ERROR;
309         break;
310 
311     case LM832x_CMD_SET_DEBOUNCE:
312         s->kbd.dbnctime = value;
313         s->reg = LM832x_GENERAL_ERROR;
314         if (!value)
315             lm_kbd_error(s, ERR_BADPAR);
316         break;
317 
318     case LM832x_CMD_SET_KEY_SIZE:
319         s->kbd.size = value;
320         s->reg = LM832x_GENERAL_ERROR;
321         if (
322                         (value & 0xf) < 3 || (value & 0xf) > LM832x_MAX_KPY ||
323                         (value >> 4) < 3 || (value >> 4) > LM832x_MAX_KPX)
324             lm_kbd_error(s, ERR_BADPAR);
325         break;
326 
327     case LM832x_CMD_WRITE_CLOCK:
328         s->clock = value;
329         s->reg = LM832x_GENERAL_ERROR;
330         if ((value & 3) && (value & 3) != 3) {
331             lm_kbd_error(s, ERR_BADPAR);
332             fprintf(stderr, "%s: invalid clock setting in RCPWM\n",
333                             __FUNCTION__);
334         }
335         /* TODO: Validate that the command is only issued once */
336         break;
337 
338     case LM832x_CMD_PWM_WRITE:
339         if (byte == 0) {
340             if (!(value & 3) || (value >> 2) > 59) {
341                 lm_kbd_error(s, ERR_BADPAR);
342                 s->reg = LM832x_GENERAL_ERROR;
343                 break;
344             }
345 
346             s->pwm.faddr = value;
347             s->pwm.file[s->pwm.faddr] = 0;
348         } else if (byte == 1) {
349             s->pwm.file[s->pwm.faddr] |= value << 8;
350         } else if (byte == 2) {
351             s->pwm.file[s->pwm.faddr] |= value << 0;
352             s->reg = LM832x_GENERAL_ERROR;
353         }
354         break;
355     case LM832x_CMD_PWM_START:
356         s->reg = LM832x_GENERAL_ERROR;
357         if (!(value & 3) || (value >> 2) > 59) {
358             lm_kbd_error(s, ERR_BADPAR);
359             break;
360         }
361 
362         s->pwm.addr[(value & 3) - 1] = value >> 2;
363         lm_kbd_pwm_start(s, (value & 3) - 1);
364         break;
365     case LM832x_CMD_PWM_STOP:
366         s->reg = LM832x_GENERAL_ERROR;
367         if (!(value & 3)) {
368             lm_kbd_error(s, ERR_BADPAR);
369             break;
370         }
371 
372         timer_del(s->pwm.tm[(value & 3) - 1]);
373         break;
374 
375     case LM832x_GENERAL_ERROR:
376         lm_kbd_error(s, ERR_BADPAR);
377         break;
378     default:
379         lm_kbd_error(s, ERR_CMDUNK);
380         fprintf(stderr, "%s: unknown command %02x\n", __FUNCTION__, reg);
381         break;
382     }
383 }
384 
385 static void lm_i2c_event(I2CSlave *i2c, enum i2c_event event)
386 {
387     LM823KbdState *s = LM8323(i2c);
388 
389     switch (event) {
390     case I2C_START_RECV:
391     case I2C_START_SEND:
392         s->i2c_cycle = 0;
393         s->i2c_dir = (event == I2C_START_SEND);
394         break;
395 
396     default:
397         break;
398     }
399 }
400 
401 static int lm_i2c_rx(I2CSlave *i2c)
402 {
403     LM823KbdState *s = LM8323(i2c);
404 
405     return lm_kbd_read(s, s->reg, s->i2c_cycle ++);
406 }
407 
408 static int lm_i2c_tx(I2CSlave *i2c, uint8_t data)
409 {
410     LM823KbdState *s = LM8323(i2c);
411 
412     if (!s->i2c_cycle)
413         s->reg = data;
414     else
415         lm_kbd_write(s, s->reg, s->i2c_cycle - 1, data);
416     s->i2c_cycle ++;
417 
418     return 0;
419 }
420 
421 static int lm_kbd_post_load(void *opaque, int version_id)
422 {
423     LM823KbdState *s = opaque;
424 
425     lm_kbd_irq_update(s);
426     lm_kbd_gpio_update(s);
427 
428     return 0;
429 }
430 
431 static const VMStateDescription vmstate_lm_kbd = {
432     .name = "LM8323",
433     .version_id = 0,
434     .minimum_version_id = 0,
435     .post_load = lm_kbd_post_load,
436     .fields = (VMStateField[]) {
437         VMSTATE_I2C_SLAVE(parent_obj, LM823KbdState),
438         VMSTATE_UINT8(i2c_dir, LM823KbdState),
439         VMSTATE_UINT8(i2c_cycle, LM823KbdState),
440         VMSTATE_UINT8(reg, LM823KbdState),
441         VMSTATE_UINT8(config, LM823KbdState),
442         VMSTATE_UINT8(status, LM823KbdState),
443         VMSTATE_UINT8(acttime, LM823KbdState),
444         VMSTATE_UINT8(error, LM823KbdState),
445         VMSTATE_UINT8(clock, LM823KbdState),
446         VMSTATE_UINT16(gpio.pull, LM823KbdState),
447         VMSTATE_UINT16(gpio.mask, LM823KbdState),
448         VMSTATE_UINT16(gpio.dir, LM823KbdState),
449         VMSTATE_UINT16(gpio.level, LM823KbdState),
450         VMSTATE_UINT8(kbd.dbnctime, LM823KbdState),
451         VMSTATE_UINT8(kbd.size, LM823KbdState),
452         VMSTATE_UINT8(kbd.start, LM823KbdState),
453         VMSTATE_UINT8(kbd.len, LM823KbdState),
454         VMSTATE_BUFFER(kbd.fifo, LM823KbdState),
455         VMSTATE_UINT16_ARRAY(pwm.file, LM823KbdState, 256),
456         VMSTATE_UINT8(pwm.faddr, LM823KbdState),
457         VMSTATE_BUFFER(pwm.addr, LM823KbdState),
458         VMSTATE_TIMER_PTR_ARRAY(pwm.tm, LM823KbdState, 3),
459         VMSTATE_END_OF_LIST()
460     }
461 };
462 
463 
464 static int lm8323_init(I2CSlave *i2c)
465 {
466     LM823KbdState *s = LM8323(i2c);
467 
468     s->model = 0x8323;
469     s->pwm.tm[0] = timer_new_ns(QEMU_CLOCK_VIRTUAL, lm_kbd_pwm0_tick, s);
470     s->pwm.tm[1] = timer_new_ns(QEMU_CLOCK_VIRTUAL, lm_kbd_pwm1_tick, s);
471     s->pwm.tm[2] = timer_new_ns(QEMU_CLOCK_VIRTUAL, lm_kbd_pwm2_tick, s);
472     qdev_init_gpio_out(DEVICE(i2c), &s->nirq, 1);
473 
474     lm_kbd_reset(s);
475 
476     qemu_register_reset((void *) lm_kbd_reset, s);
477     return 0;
478 }
479 
480 void lm832x_key_event(DeviceState *dev, int key, int state)
481 {
482     LM823KbdState *s = LM8323(dev);
483 
484     if ((s->status & INT_ERROR) && (s->error & ERR_FIFOOVR))
485         return;
486 
487     if (s->kbd.len >= sizeof(s->kbd.fifo)) {
488         lm_kbd_error(s, ERR_FIFOOVR);
489         return;
490     }
491 
492     s->kbd.fifo[(s->kbd.start + s->kbd.len ++) & (sizeof(s->kbd.fifo) - 1)] =
493             key | (state << 7);
494 
495     /* We never set ERR_KEYOVR because we support multiple keys fine.  */
496     s->status |= INT_KEYPAD;
497     lm_kbd_irq_update(s);
498 }
499 
500 static void lm8323_class_init(ObjectClass *klass, void *data)
501 {
502     DeviceClass *dc = DEVICE_CLASS(klass);
503     I2CSlaveClass *k = I2C_SLAVE_CLASS(klass);
504 
505     k->init = lm8323_init;
506     k->event = lm_i2c_event;
507     k->recv = lm_i2c_rx;
508     k->send = lm_i2c_tx;
509     dc->vmsd = &vmstate_lm_kbd;
510 }
511 
512 static const TypeInfo lm8323_info = {
513     .name          = TYPE_LM8323,
514     .parent        = TYPE_I2C_SLAVE,
515     .instance_size = sizeof(LM823KbdState),
516     .class_init    = lm8323_class_init,
517 };
518 
519 static void lm832x_register_types(void)
520 {
521     type_register_static(&lm8323_info);
522 }
523 
524 type_init(lm832x_register_types)
525