qemu

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/*
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 * MAX7310 8-port GPIO expansion chip.
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 *
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 * Copyright (c) 2006 Openedhand Ltd.
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 * Written by Andrzej Zaborowski <balrog@zabor.org>
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 *
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 * This file is licensed under GNU GPL.
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 */
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#include "qemu/osdep.h"
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#include "hw/i2c/i2c.h"
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#include "hw/irq.h"
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#include "migration/vmstate.h"
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#include "qemu/log.h"
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#include "qemu/module.h"
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#include "qom/object.h"
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#define TYPE_MAX7310 "max7310"
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OBJECT_DECLARE_SIMPLE_TYPE(MAX7310State, MAX7310)
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struct MAX7310State {
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    I2CSlave parent_obj;
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    int i2c_command_byte;
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    int len;
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    uint8_t level;
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    uint8_t direction;
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    uint8_t polarity;
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    uint8_t status;
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    uint8_t command;
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    qemu_irq handler[8];
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    qemu_irq *gpio_in;
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};
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static void max7310_reset(DeviceState *dev)
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{
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    MAX7310State *s = MAX7310(dev);
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    s->level &= s->direction;
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    s->direction = 0xff;
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    s->polarity = 0xf0;
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    s->status = 0x01;
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    s->command = 0x00;
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}
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static uint8_t max7310_rx(I2CSlave *i2c)
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{
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    MAX7310State *s = MAX7310(i2c);
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    switch (s->command) {
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    case 0x00:  /* Input port */
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        return s->level ^ s->polarity;
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    case 0x01:  /* Output port */
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        return s->level & ~s->direction;
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    case 0x02:  /* Polarity inversion */
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        return s->polarity;
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    case 0x03:  /* Configuration */
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        return s->direction;
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    case 0x04:  /* Timeout */
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        return s->status;
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    case 0xff:  /* Reserved */
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        return 0xff;
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    default:
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        qemu_log_mask(LOG_UNIMP, "%s: Unsupported register 0x02%" PRIx8 "\n",
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                      __func__, s->command);
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        break;
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    }
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    return 0xff;
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}
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static int max7310_tx(I2CSlave *i2c, uint8_t data)
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{
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    MAX7310State *s = MAX7310(i2c);
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    uint8_t diff;
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    int line;
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    if (s->len ++ > 1) {
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#ifdef VERBOSE
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        printf("%s: message too long (%i bytes)\n", __func__, s->len);
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#endif
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        return 1;
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    }
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    if (s->i2c_command_byte) {
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        s->command = data;
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        s->i2c_command_byte = 0;
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        return 0;
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    }
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    switch (s->command) {
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    case 0x01:  /* Output port */
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        for (diff = (data ^ s->level) & ~s->direction; diff;
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                        diff &= ~(1 << line)) {
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            line = ctz32(diff);
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            if (s->handler[line])
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                qemu_set_irq(s->handler[line], (data >> line) & 1);
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        }
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        s->level = (s->level & s->direction) | (data & ~s->direction);
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        break;
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    case 0x02:  /* Polarity inversion */
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        s->polarity = data;
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        break;
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    case 0x03:  /* Configuration */
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        s->level &= ~(s->direction ^ data);
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        s->direction = data;
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        break;
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    case 0x04:  /* Timeout */
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        s->status = data;
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        break;
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    case 0x00:  /* Input port - ignore writes */
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        break;
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    default:
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        qemu_log_mask(LOG_UNIMP, "%s: Unsupported register 0x02%" PRIx8 "\n",
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                      __func__, s->command);
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        return 1;
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    }
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    return 0;
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}
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static int max7310_event(I2CSlave *i2c, enum i2c_event event)
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{
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    MAX7310State *s = MAX7310(i2c);
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    s->len = 0;
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    switch (event) {
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    case I2C_START_SEND:
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        s->i2c_command_byte = 1;
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        break;
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    case I2C_FINISH:
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#ifdef VERBOSE
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        if (s->len == 1)
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            printf("%s: message too short (%i bytes)\n", __func__, s->len);
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#endif
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        break;
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    default:
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        break;
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    }
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    return 0;
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}
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static const VMStateDescription vmstate_max7310 = {
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    .name = "max7310",
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    .version_id = 0,
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    .minimum_version_id = 0,
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    .fields = (const VMStateField[]) {
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        VMSTATE_INT32(i2c_command_byte, MAX7310State),
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        VMSTATE_INT32(len, MAX7310State),
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        VMSTATE_UINT8(level, MAX7310State),
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        VMSTATE_UINT8(direction, MAX7310State),
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        VMSTATE_UINT8(polarity, MAX7310State),
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        VMSTATE_UINT8(status, MAX7310State),
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        VMSTATE_UINT8(command, MAX7310State),
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        VMSTATE_I2C_SLAVE(parent_obj, MAX7310State),
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        VMSTATE_END_OF_LIST()
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    }
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};
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static void max7310_gpio_set(void *opaque, int line, int level)
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{
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    MAX7310State *s = (MAX7310State *) opaque;
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    assert(line >= 0 && line < ARRAY_SIZE(s->handler));
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    if (level)
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        s->level |= s->direction & (1 << line);
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    else
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        s->level &= ~(s->direction & (1 << line));
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}
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/* MAX7310 is SMBus-compatible (can be used with only SMBus protocols),
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 * but also accepts sequences that are not SMBus so return an I2C device.  */
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static void max7310_realize(DeviceState *dev, Error **errp)
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{
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    MAX7310State *s = MAX7310(dev);
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    qdev_init_gpio_in(dev, max7310_gpio_set, ARRAY_SIZE(s->handler));
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    qdev_init_gpio_out(dev, s->handler, ARRAY_SIZE(s->handler));
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}
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static void max7310_class_init(ObjectClass *klass, void *data)
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{
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    DeviceClass *dc = DEVICE_CLASS(klass);
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    I2CSlaveClass *k = I2C_SLAVE_CLASS(klass);
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    dc->realize = max7310_realize;
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    k->event = max7310_event;
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    k->recv = max7310_rx;
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    k->send = max7310_tx;
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    dc->reset = max7310_reset;
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    dc->vmsd = &vmstate_max7310;
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}
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static const TypeInfo max7310_info = {
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    .name          = TYPE_MAX7310,
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    .parent        = TYPE_I2C_SLAVE,
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    .instance_size = sizeof(MAX7310State),
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    .class_init    = max7310_class_init,
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};
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static void max7310_register_types(void)
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{
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    type_register_static(&max7310_info);
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}
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type_init(max7310_register_types)
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