qemu

max7310.c (5214B)

---

 /*
  * MAX7310 8-port GPIO expansion chip.
  *
  * Copyright (c) 2006 Openedhand Ltd.
  * Written by Andrzej Zaborowski <balrog@zabor.org>
  *
  * This file is licensed under GNU GPL.
  */
 
 #include "qemu/osdep.h"
 #include "hw/i2c/i2c.h"
 #include "hw/irq.h"
 #include "migration/vmstate.h"
 #include "qemu/log.h"
 #include "qemu/module.h"
 #include "qom/object.h"
 
 #define TYPE_MAX7310 "max7310"
 OBJECT_DECLARE_SIMPLE_TYPE(MAX7310State, MAX7310)
 
 struct MAX7310State {
     I2CSlave parent_obj;
 
     int i2c_command_byte;
     int len;
 
     uint8_t level;
     uint8_t direction;
     uint8_t polarity;
     uint8_t status;
     uint8_t command;
     qemu_irq handler[8];
     qemu_irq *gpio_in;
 };
 
 static void max7310_reset(DeviceState *dev)
 {
     MAX7310State *s = MAX7310(dev);
 
     s->level &= s->direction;
     s->direction = 0xff;
     s->polarity = 0xf0;
     s->status = 0x01;
     s->command = 0x00;
 }
 
 static uint8_t max7310_rx(I2CSlave *i2c)
 {
     MAX7310State *s = MAX7310(i2c);
 
     switch (s->command) {
     case 0x00:	/* Input port */
         return s->level ^ s->polarity;
 
     case 0x01:	/* Output port */
         return s->level & ~s->direction;
 
     case 0x02:	/* Polarity inversion */
         return s->polarity;
 
     case 0x03:	/* Configuration */
         return s->direction;
 
     case 0x04:	/* Timeout */
         return s->status;
 
     case 0xff:	/* Reserved */
         return 0xff;
 
     default:
         qemu_log_mask(LOG_UNIMP, "%s: Unsupported register 0x02%" PRIx8 "\n",
                       __func__, s->command);
         break;
     }
     return 0xff;
 }
 
 static int max7310_tx(I2CSlave *i2c, uint8_t data)
 {
     MAX7310State *s = MAX7310(i2c);
     uint8_t diff;
     int line;
 
     if (s->len ++ > 1) {
 #ifdef VERBOSE
         printf("%s: message too long (%i bytes)\n", __func__, s->len);
 #endif
         return 1;
     }
 
     if (s->i2c_command_byte) {
         s->command = data;
         s->i2c_command_byte = 0;
         return 0;
     }
 
     switch (s->command) {
     case 0x01:	/* Output port */
         for (diff = (data ^ s->level) & ~s->direction; diff;
                         diff &= ~(1 << line)) {
             line = ctz32(diff);
             if (s->handler[line])
                 qemu_set_irq(s->handler[line], (data >> line) & 1);
         }
         s->level = (s->level & s->direction) | (data & ~s->direction);
         break;
 
     case 0x02:	/* Polarity inversion */
         s->polarity = data;
         break;
 
     case 0x03:	/* Configuration */
         s->level &= ~(s->direction ^ data);
         s->direction = data;
         break;
 
     case 0x04:	/* Timeout */
         s->status = data;
         break;
 
     case 0x00:	/* Input port - ignore writes */
         break;
     default:
         qemu_log_mask(LOG_UNIMP, "%s: Unsupported register 0x02%" PRIx8 "\n",
                       __func__, s->command);
         return 1;
     }
 
     return 0;
 }
 
 static int max7310_event(I2CSlave *i2c, enum i2c_event event)
 {
     MAX7310State *s = MAX7310(i2c);
     s->len = 0;
 
     switch (event) {
     case I2C_START_SEND:
         s->i2c_command_byte = 1;
         break;
     case I2C_FINISH:
 #ifdef VERBOSE
         if (s->len == 1)
             printf("%s: message too short (%i bytes)\n", __func__, s->len);
 #endif
         break;
     default:
         break;
     }
 
     return 0;
 }
 
 static const VMStateDescription vmstate_max7310 = {
     .name = "max7310",
     .version_id = 0,
     .minimum_version_id = 0,
     .fields = (VMStateField[]) {
         VMSTATE_INT32(i2c_command_byte, MAX7310State),
         VMSTATE_INT32(len, MAX7310State),
         VMSTATE_UINT8(level, MAX7310State),
         VMSTATE_UINT8(direction, MAX7310State),
         VMSTATE_UINT8(polarity, MAX7310State),
         VMSTATE_UINT8(status, MAX7310State),
         VMSTATE_UINT8(command, MAX7310State),
         VMSTATE_I2C_SLAVE(parent_obj, MAX7310State),
         VMSTATE_END_OF_LIST()
     }
 };
 
 static void max7310_gpio_set(void *opaque, int line, int level)
 {
     MAX7310State *s = (MAX7310State *) opaque;
     assert(line >= 0 && line < ARRAY_SIZE(s->handler));
 
     if (level)
         s->level |= s->direction & (1 << line);
     else
         s->level &= ~(s->direction & (1 << line));
 }
 
 /* MAX7310 is SMBus-compatible (can be used with only SMBus protocols),
  * but also accepts sequences that are not SMBus so return an I2C device.  */
 static void max7310_realize(DeviceState *dev, Error **errp)
 {
     I2CSlave *i2c = I2C_SLAVE(dev);
     MAX7310State *s = MAX7310(dev);
 
     qdev_init_gpio_in(&i2c->qdev, max7310_gpio_set, 8);
     qdev_init_gpio_out(&i2c->qdev, s->handler, 8);
 }
 
 static void max7310_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
     I2CSlaveClass *k = I2C_SLAVE_CLASS(klass);
 
     dc->realize = max7310_realize;
     k->event = max7310_event;
     k->recv = max7310_rx;
     k->send = max7310_tx;
     dc->reset = max7310_reset;
     dc->vmsd = &vmstate_max7310;
 }
 
 static const TypeInfo max7310_info = {
     .name          = TYPE_MAX7310,
     .parent        = TYPE_I2C_SLAVE,
     .instance_size = sizeof(MAX7310State),
     .class_init    = max7310_class_init,
 };
 
 static void max7310_register_types(void)
 {
     type_register_static(&max7310_info);
 }
 
 type_init(max7310_register_types)