1 #ifndef QEMU_I2C_H 2 #define QEMU_I2C_H 3 4 #include "hw/qdev-core.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 11 enum i2c_event { 12 I2C_START_RECV, 13 I2C_START_SEND, 14 I2C_FINISH, 15 I2C_NACK /* Masker NACKed a receive byte. */ 16 }; 17 18 typedef 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 28 typedef 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. 37 */ 38 uint8_t (*recv)(I2CSlave *s); 39 40 /* 41 * Notify the slave of a bus state change. For start event, 42 * returns non-zero to NAK an operation. For other events the 43 * return code is not used and should be zero. 44 */ 45 int (*event)(I2CSlave *s, enum i2c_event event); 46 } I2CSlaveClass; 47 48 struct I2CSlave { 49 DeviceState qdev; 50 51 /* Remaining fields for internal use by the I2C code. */ 52 uint8_t address; 53 }; 54 55 #define TYPE_I2C_BUS "i2c-bus" 56 #define I2C_BUS(obj) OBJECT_CHECK(I2CBus, (obj), TYPE_I2C_BUS) 57 58 typedef struct I2CNode I2CNode; 59 60 struct I2CNode { 61 I2CSlave *elt; 62 QLIST_ENTRY(I2CNode) next; 63 }; 64 65 struct I2CBus { 66 BusState qbus; 67 QLIST_HEAD(, I2CNode) current_devs; 68 uint8_t saved_address; 69 bool broadcast; 70 }; 71 72 I2CBus *i2c_init_bus(DeviceState *parent, const char *name); 73 void i2c_set_slave_address(I2CSlave *dev, uint8_t address); 74 int i2c_bus_busy(I2CBus *bus); 75 int i2c_start_transfer(I2CBus *bus, uint8_t address, int recv); 76 void i2c_end_transfer(I2CBus *bus); 77 void i2c_nack(I2CBus *bus); 78 int i2c_send_recv(I2CBus *bus, uint8_t *data, bool send); 79 int i2c_send(I2CBus *bus, uint8_t data); 80 uint8_t i2c_recv(I2CBus *bus); 81 82 /** 83 * Create an I2C slave device on the heap. 84 * @name: a device type name 85 * @addr: I2C address of the slave when put on a bus 86 * 87 * This only initializes the device state structure and allows 88 * properties to be set. Type @name must exist. The device still 89 * needs to be realized. See qdev-core.h. 90 */ 91 I2CSlave *i2c_slave_new(const char *name, uint8_t addr); 92 93 /** 94 * Create and realize an I2C slave device on the heap. 95 * @bus: I2C bus to put it on 96 * @name: I2C slave device type name 97 * @addr: I2C address of the slave when put on a bus 98 * 99 * Create the device state structure, initialize it, put it on the 100 * specified @bus, and drop the reference to it (the device is realized). 101 */ 102 I2CSlave *i2c_slave_create_simple(I2CBus *bus, const char *name, uint8_t addr); 103 104 /** 105 * Realize and and drop a reference an I2C slave device 106 * @dev: I2C slave device to realize 107 * @bus: I2C bus to put it on 108 * @addr: I2C address of the slave on the bus 109 * @errp: pointer to NULL initialized error object 110 * 111 * Returns: %true on success, %false on failure. 112 * 113 * Call 'realize' on @dev, put it on the specified @bus, and drop the 114 * reference to it. 115 * 116 * This function is useful if you have created @dev via qdev_new(), 117 * i2c_slave_new() or i2c_slave_try_new() (which take a reference to 118 * the device it returns to you), so that you can set properties on it 119 * before realizing it. If you don't need to set properties then 120 * i2c_slave_create_simple() is probably better (as it does the create, 121 * init and realize in one step). 122 * 123 * If you are embedding the I2C slave into another QOM device and 124 * initialized it via some variant on object_initialize_child() then 125 * do not use this function, because that family of functions arrange 126 * for the only reference to the child device to be held by the parent 127 * via the child<> property, and so the reference-count-drop done here 128 * would be incorrect. (Instead you would want i2c_slave_realize(), 129 * which doesn't currently exist but would be trivial to create if we 130 * had any code that wanted it.) 131 */ 132 bool i2c_slave_realize_and_unref(I2CSlave *dev, I2CBus *bus, Error **errp); 133 134 /* lm832x.c */ 135 void lm832x_key_event(DeviceState *dev, int key, int state); 136 137 extern const VMStateDescription vmstate_i2c_slave; 138 139 #define VMSTATE_I2C_SLAVE(_field, _state) { \ 140 .name = (stringify(_field)), \ 141 .size = sizeof(I2CSlave), \ 142 .vmsd = &vmstate_i2c_slave, \ 143 .flags = VMS_STRUCT, \ 144 .offset = vmstate_offset_value(_state, _field, I2CSlave), \ 145 } 146 147 #endif 148