LXR qemu/hw/gpio/max7310.c

   1/*
   2 * MAX7310 8-port GPIO expansion chip.
   3 *
   4 * Copyright (c) 2006 Openedhand Ltd.
   5 * Written by Andrzej Zaborowski <balrog@zabor.org>
   6 *
   7 * This file is licensed under GNU GPL.
   8 */
   9
  10#include "qemu/osdep.h"
  11#include "hw/i2c/i2c.h"
  12#include "hw/irq.h"
  13#include "migration/vmstate.h"
  14#include "qemu/log.h"
  15#include "qemu/module.h"
  16#include "qom/object.h"
  17
  18#define TYPE_MAX7310 "max7310"
  19OBJECT_DECLARE_SIMPLE_TYPE(MAX7310State, MAX7310)
  20
  21struct MAX7310State {
  22    I2CSlave parent_obj;
  23
  24    int i2c_command_byte;
  25    int len;
  26
  27    uint8_t level;
  28    uint8_t direction;
  29    uint8_t polarity;
  30    uint8_t status;
  31    uint8_t command;
  32    qemu_irq handler[8];
  33    qemu_irq *gpio_in;
  34};
  35
  36static void max7310_reset(DeviceState *dev)
  37{
  38    MAX7310State *s = MAX7310(dev);
  39
  40    s->level &= s->direction;
  41    s->direction = 0xff;
  42    s->polarity = 0xf0;
  43    s->status = 0x01;
  44    s->command = 0x00;
  45}
  46
  47static uint8_t max7310_rx(I2CSlave *i2c)
  48{
  49    MAX7310State *s = MAX7310(i2c);
  50
  51    switch (s->command) {
  52    case 0x00:  /* Input port */
  53        return s->level ^ s->polarity;
  54
  55    case 0x01:  /* Output port */
  56        return s->level & ~s->direction;
  57
  58    case 0x02:  /* Polarity inversion */
  59        return s->polarity;
  60
  61    case 0x03:  /* Configuration */
  62        return s->direction;
  63
  64    case 0x04:  /* Timeout */
  65        return s->status;
  66
  67    case 0xff:  /* Reserved */
  68        return 0xff;
  69
  70    default:
  71        qemu_log_mask(LOG_UNIMP, "%s: Unsupported register 0x02%" PRIx8 "\n",
  72                      __func__, s->command);
  73        break;
  74    }
  75    return 0xff;
  76}
  77
  78static int max7310_tx(I2CSlave *i2c, uint8_t data)
  79{
  80    MAX7310State *s = MAX7310(i2c);
  81    uint8_t diff;
  82    int line;
  83
  84    if (s->len ++ > 1) {
  85#ifdef VERBOSE
  86        printf("%s: message too long (%i bytes)\n", __func__, s->len);
  87#endif
  88        return 1;
  89    }
  90
  91    if (s->i2c_command_byte) {
  92        s->command = data;
  93        s->i2c_command_byte = 0;
  94        return 0;
  95    }
  96
  97    switch (s->command) {
  98    case 0x01:  /* Output port */
  99        for (diff = (data ^ s->level) & ~s->direction; diff;
 100                        diff &= ~(1 << line)) {
 101            line = ctz32(diff);
 102            if (s->handler[line])
 103                qemu_set_irq(s->handler[line], (data >> line) & 1);
 104        }
 105        s->level = (s->level & s->direction) | (data & ~s->direction);
 106        break;
 107
 108    case 0x02:  /* Polarity inversion */
 109        s->polarity = data;
 110        break;
 111
 112    case 0x03:  /* Configuration */
 113        s->level &= ~(s->direction ^ data);
 114        s->direction = data;
 115        break;
 116
 117    case 0x04:  /* Timeout */
 118        s->status = data;
 119        break;
 120
 121    case 0x00:  /* Input port - ignore writes */
 122        break;
 123    default:
 124        qemu_log_mask(LOG_UNIMP, "%s: Unsupported register 0x02%" PRIx8 "\n",
 125                      __func__, s->command);
 126        return 1;
 127    }
 128
 129    return 0;
 130}
 131
 132static int max7310_event(I2CSlave *i2c, enum i2c_event event)
 133{
 134    MAX7310State *s = MAX7310(i2c);
 135    s->len = 0;
 136
 137    switch (event) {
 138    case I2C_START_SEND:
 139        s->i2c_command_byte = 1;
 140        break;
 141    case I2C_FINISH:
 142#ifdef VERBOSE
 143        if (s->len == 1)
 144            printf("%s: message too short (%i bytes)\n", __func__, s->len);
 145#endif
 146        break;
 147    default:
 148        break;
 149    }
 150
 151    return 0;
 152}
 153
 154static const VMStateDescription vmstate_max7310 = {
 155    .name = "max7310",
 156    .version_id = 0,
 157    .minimum_version_id = 0,
 158    .fields = (VMStateField[]) {
 159        VMSTATE_INT32(i2c_command_byte, MAX7310State),
 160        VMSTATE_INT32(len, MAX7310State),
 161        VMSTATE_UINT8(level, MAX7310State),
 162        VMSTATE_UINT8(direction, MAX7310State),
 163        VMSTATE_UINT8(polarity, MAX7310State),
 164        VMSTATE_UINT8(status, MAX7310State),
 165        VMSTATE_UINT8(command, MAX7310State),
 166        VMSTATE_I2C_SLAVE(parent_obj, MAX7310State),
 167        VMSTATE_END_OF_LIST()
 168    }
 169};
 170
 171static void max7310_gpio_set(void *opaque, int line, int level)
 172{
 173    MAX7310State *s = (MAX7310State *) opaque;
 174    assert(line >= 0 && line < ARRAY_SIZE(s->handler));
 175
 176    if (level)
 177        s->level |= s->direction & (1 << line);
 178    else
 179        s->level &= ~(s->direction & (1 << line));
 180}
 181
 182/* MAX7310 is SMBus-compatible (can be used with only SMBus protocols),
 183 * but also accepts sequences that are not SMBus so return an I2C device.  */
 184static void max7310_realize(DeviceState *dev, Error **errp)
 185{
 186    I2CSlave *i2c = I2C_SLAVE(dev);
 187    MAX7310State *s = MAX7310(dev);
 188
 189    qdev_init_gpio_in(&i2c->qdev, max7310_gpio_set, 8);
 190    qdev_init_gpio_out(&i2c->qdev, s->handler, 8);
 191}
 192
 193static void max7310_class_init(ObjectClass *klass, void *data)
 194{
 195    DeviceClass *dc = DEVICE_CLASS(klass);
 196    I2CSlaveClass *k = I2C_SLAVE_CLASS(klass);
 197
 198    dc->realize = max7310_realize;
 199    k->event = max7310_event;
 200    k->recv = max7310_rx;
 201    k->send = max7310_tx;
 202    dc->reset = max7310_reset;
 203    dc->vmsd = &vmstate_max7310;
 204}
 205
 206static const TypeInfo max7310_info = {
 207    .name          = TYPE_MAX7310,
 208    .parent        = TYPE_I2C_SLAVE,
 209    .instance_size = sizeof(MAX7310State),
 210    .class_init    = max7310_class_init,
 211};
 212
 213static void max7310_register_types(void)
 214{
 215    type_register_static(&max7310_info);
 216}
 217
 218type_init(max7310_register_types)
 219