1 #ifndef QEMU_I2C_H 2 #define QEMU_I2C_H 3 4 #include "hw/qdev-core.h" 5 #include "qom/object.h" 6 7 /* The QEMU I2C implementation only supports simple transfers that complete 8 immediately. It does not support slave devices that need to be able to 9 defer their response (eg. CPU slave interfaces where the data is supplied 10 by the device driver in response to an interrupt). */ 11 12 enum i2c_event { 13 I2C_START_RECV, 14 I2C_START_SEND, 15 I2C_FINISH, 16 I2C_NACK /* Masker NACKed a receive byte. */ 17 }; 18 19 20 #define TYPE_I2C_SLAVE "i2c-slave" 21 OBJECT_DECLARE_TYPE(I2CSlave, I2CSlaveClass, 22 I2C_SLAVE) 23 24 struct I2CSlaveClass { 25 DeviceClass parent_class; 26 27 /* Master to slave. Returns non-zero for a NAK, 0 for success. */ 28 int (*send)(I2CSlave *s, uint8_t data); 29 30 /* 31 * Slave to master. This cannot fail, the device should always 32 * return something here. 33 */ 34 uint8_t (*recv)(I2CSlave *s); 35 36 /* 37 * Notify the slave of a bus state change. For start event, 38 * returns non-zero to NAK an operation. For other events the 39 * return code is not used and should be zero. 40 */ 41 int (*event)(I2CSlave *s, enum i2c_event event); 42 }; 43 44 struct I2CSlave { 45 DeviceState qdev; 46 47 /* Remaining fields for internal use by the I2C code. */ 48 uint8_t address; 49 }; 50 51 #define TYPE_I2C_BUS "i2c-bus" 52 OBJECT_DECLARE_SIMPLE_TYPE(I2CBus, I2C_BUS) 53 54 typedef struct I2CNode I2CNode; 55 56 struct I2CNode { 57 I2CSlave *elt; 58 QLIST_ENTRY(I2CNode) next; 59 }; 60 61 struct I2CBus { 62 BusState qbus; 63 QLIST_HEAD(, I2CNode) current_devs; 64 uint8_t saved_address; 65 bool broadcast; 66 }; 67 68 I2CBus *i2c_init_bus(DeviceState *parent, const char *name); 69 void i2c_set_slave_address(I2CSlave *dev, uint8_t address); 70 int i2c_bus_busy(I2CBus *bus); 71 int i2c_start_transfer(I2CBus *bus, uint8_t address, int recv); 72 void i2c_end_transfer(I2CBus *bus); 73 void i2c_nack(I2CBus *bus); 74 int i2c_send_recv(I2CBus *bus, uint8_t *data, bool send); 75 int i2c_send(I2CBus *bus, uint8_t data); 76 uint8_t i2c_recv(I2CBus *bus); 77 78 /** 79 * Create an I2C slave device on the heap. 80 * @name: a device type name 81 * @addr: I2C address of the slave when put on a bus 82 * 83 * This only initializes the device state structure and allows 84 * properties to be set. Type @name must exist. The device still 85 * needs to be realized. See qdev-core.h. 86 */ 87 I2CSlave *i2c_slave_new(const char *name, uint8_t addr); 88 89 /** 90 * Create and realize an I2C slave device on the heap. 91 * @bus: I2C bus to put it on 92 * @name: I2C slave device type name 93 * @addr: I2C address of the slave when put on a bus 94 * 95 * Create the device state structure, initialize it, put it on the 96 * specified @bus, and drop the reference to it (the device is realized). 97 */ 98 I2CSlave *i2c_slave_create_simple(I2CBus *bus, const char *name, uint8_t addr); 99 100 /** 101 * Realize and drop a reference an I2C slave device 102 * @dev: I2C slave device to realize 103 * @bus: I2C bus to put it on 104 * @addr: I2C address of the slave on the bus 105 * @errp: pointer to NULL initialized error object 106 * 107 * Returns: %true on success, %false on failure. 108 * 109 * Call 'realize' on @dev, put it on the specified @bus, and drop the 110 * reference to it. 111 * 112 * This function is useful if you have created @dev via qdev_new(), 113 * i2c_slave_new() or i2c_slave_try_new() (which take a reference to 114 * the device it returns to you), so that you can set properties on it 115 * before realizing it. If you don't need to set properties then 116 * i2c_slave_create_simple() is probably better (as it does the create, 117 * init and realize in one step). 118 * 119 * If you are embedding the I2C slave into another QOM device and 120 * initialized it via some variant on object_initialize_child() then 121 * do not use this function, because that family of functions arrange 122 * for the only reference to the child device to be held by the parent 123 * via the child<> property, and so the reference-count-drop done here 124 * would be incorrect. (Instead you would want i2c_slave_realize(), 125 * which doesn't currently exist but would be trivial to create if we 126 * had any code that wanted it.) 127 */ 128 bool i2c_slave_realize_and_unref(I2CSlave *dev, I2CBus *bus, Error **errp); 129 130 /* lm832x.c */ 131 void lm832x_key_event(DeviceState *dev, int key, int state); 132 133 extern const VMStateDescription vmstate_i2c_slave; 134 135 #define VMSTATE_I2C_SLAVE(_field, _state) { \ 136 .name = (stringify(_field)), \ 137 .size = sizeof(I2CSlave), \ 138 .vmsd = &vmstate_i2c_slave, \ 139 .flags = VMS_STRUCT, \ 140 .offset = vmstate_offset_value(_state, _field, I2CSlave), \ 141 } 142 143 #endif 144