LXR qemu/include/hw/i2c/i2c.h

   1#ifndef QEMU_I2C_H
   2#define QEMU_I2C_H
   3
   4#include "hw/qdev.h"
   5
   6/* The QEMU I2C implementation only supports simple transfers that complete
   7   immediately.  It does not support slave devices that need to be able to
   8   defer their response (eg. CPU slave interfaces where the data is supplied
   9   by the device driver in response to an interrupt).  */
  10
  11enum i2c_event {
  12    I2C_START_RECV,
  13    I2C_START_SEND,
  14    I2C_FINISH,
  15    I2C_NACK /* Masker NACKed a receive byte.  */
  16};
  17
  18typedef struct I2CSlave I2CSlave;
  19
  20#define TYPE_I2C_SLAVE "i2c-slave"
  21#define I2C_SLAVE(obj) \
  22     OBJECT_CHECK(I2CSlave, (obj), TYPE_I2C_SLAVE)
  23#define I2C_SLAVE_CLASS(klass) \
  24     OBJECT_CLASS_CHECK(I2CSlaveClass, (klass), TYPE_I2C_SLAVE)
  25#define I2C_SLAVE_GET_CLASS(obj) \
  26     OBJECT_GET_CLASS(I2CSlaveClass, (obj), TYPE_I2C_SLAVE)
  27
  28typedef struct I2CSlaveClass {
  29    DeviceClass parent_class;
  30
  31    /* Master to slave. Returns non-zero for a NAK, 0 for success. */
  32    int (*send)(I2CSlave *s, uint8_t data);
  33
  34    /*
  35     * Slave to master.  This cannot fail, the device should always
  36     * return something here.  Negative values probably result in 0xff
  37     * and a possible log from the driver, and shouldn't be used.
  38     */
  39    int (*recv)(I2CSlave *s);
  40
  41    /*
  42     * Notify the slave of a bus state change.  For start event,
  43     * returns non-zero to NAK an operation.  For other events the
  44     * return code is not used and should be zero.
  45     */
  46    int (*event)(I2CSlave *s, enum i2c_event event);
  47} I2CSlaveClass;
  48
  49struct I2CSlave {
  50    DeviceState qdev;
  51
  52    /* Remaining fields for internal use by the I2C code.  */
  53    uint8_t address;
  54};
  55
  56#define TYPE_I2C_BUS "i2c-bus"
  57#define I2C_BUS(obj) OBJECT_CHECK(I2CBus, (obj), TYPE_I2C_BUS)
  58
  59typedef struct I2CNode I2CNode;
  60
  61struct I2CNode {
  62    I2CSlave *elt;
  63    QLIST_ENTRY(I2CNode) next;
  64};
  65
  66struct I2CBus {
  67    BusState qbus;
  68    QLIST_HEAD(, I2CNode) current_devs;
  69    uint8_t saved_address;
  70    bool broadcast;
  71};
  72
  73I2CBus *i2c_init_bus(DeviceState *parent, const char *name);
  74void i2c_set_slave_address(I2CSlave *dev, uint8_t address);
  75int i2c_bus_busy(I2CBus *bus);
  76int i2c_start_transfer(I2CBus *bus, uint8_t address, int recv);
  77void i2c_end_transfer(I2CBus *bus);
  78void i2c_nack(I2CBus *bus);
  79int i2c_send_recv(I2CBus *bus, uint8_t *data, bool send);
  80int i2c_send(I2CBus *bus, uint8_t data);
  81int i2c_recv(I2CBus *bus);
  82
  83DeviceState *i2c_create_slave(I2CBus *bus, const char *name, uint8_t addr);
  84
  85typedef struct bitbang_i2c_interface bitbang_i2c_interface;
  86
  87/* lm832x.c */
  88void lm832x_key_event(DeviceState *dev, int key, int state);
  89
  90extern const VMStateDescription vmstate_i2c_slave;
  91
  92#define VMSTATE_I2C_SLAVE(_field, _state) {                          \
  93    .name       = (stringify(_field)),                               \
  94    .size       = sizeof(I2CSlave),                                  \
  95    .vmsd       = &vmstate_i2c_slave,                                \
  96    .flags      = VMS_STRUCT,                                        \
  97    .offset     = vmstate_offset_value(_state, _field, I2CSlave),    \
  98}
  99
 100#endif
 101