| 1 | #ifndef QEMU_I2C_H |
| 2 | #define QEMU_I2C_H |
| 3 | |
| 4 | #include "hw/core/qdev.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_START_SEND_ASYNC, |
| 16 | I2C_FINISH, |
| 17 | I2C_NACK /* Masker NACKed a receive byte. */ |
| 18 | }; |
| 19 | |
| 20 | typedef struct I2CNodeList I2CNodeList; |
| 21 | |
| 22 | #define TYPE_I2C_SLAVE "i2c-slave" |
| 23 | OBJECT_DECLARE_TYPE(I2CSlave, I2CSlaveClass, |
| 24 | I2C_SLAVE) |
| 25 | |
| 26 | struct I2CSlaveClass { |
| 27 | DeviceClass parent_class; |
| 28 | |
| 29 | /* Master to slave. Returns non-zero for a NAK, 0 for success. */ |
| 30 | int (*send)(I2CSlave *s, uint8_t data); |
| 31 | |
| 32 | /* Master to slave (asynchronous). Receiving slave must call i2c_ack(). */ |
| 33 | void (*send_async)(I2CSlave *s, uint8_t data); |
| 34 | |
| 35 | /* |
| 36 | * Slave to master. This cannot fail, the device should always |
| 37 | * return something here. |
| 38 | */ |
| 39 | uint8_t (*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 | |
| 48 | /* |
| 49 | * Check if this device matches the address provided. Returns bool of |
| 50 | * true if it matches (or broadcast), and updates the device list, false |
| 51 | * otherwise. |
| 52 | * |
| 53 | * If broadcast is true, match should add the device and return true. |
| 54 | */ |
| 55 | bool (*match_and_add)(I2CSlave *candidate, uint8_t address, bool broadcast, |
| 56 | I2CNodeList *current_devs); |
| 57 | }; |
| 58 | |
| 59 | struct I2CSlave { |
| 60 | DeviceState qdev; |
| 61 | |
| 62 | /* Remaining fields for internal use by the I2C code. */ |
| 63 | uint8_t address; |
| 64 | }; |
| 65 | |
| 66 | #define TYPE_I2C_BUS "i2c-bus" |
| 67 | OBJECT_DECLARE_SIMPLE_TYPE(I2CBus, I2C_BUS) |
| 68 | |
| 69 | typedef struct I2CNode I2CNode; |
| 70 | |
| 71 | struct I2CNode { |
| 72 | I2CSlave *elt; |
| 73 | QLIST_ENTRY(I2CNode) next; |
| 74 | }; |
| 75 | |
| 76 | typedef struct I2CPendingMaster I2CPendingMaster; |
| 77 | |
| 78 | struct I2CPendingMaster { |
| 79 | QEMUBH *bh; |
| 80 | QSIMPLEQ_ENTRY(I2CPendingMaster) entry; |
| 81 | }; |
| 82 | |
| 83 | typedef QLIST_HEAD(I2CNodeList, I2CNode) I2CNodeList; |
| 84 | typedef QSIMPLEQ_HEAD(I2CPendingMasters, I2CPendingMaster) I2CPendingMasters; |
| 85 | |
| 86 | struct I2CBus { |
| 87 | BusState qbus; |
| 88 | I2CNodeList current_devs; |
| 89 | I2CPendingMasters pending_masters; |
| 90 | uint8_t saved_address; |
| 91 | bool broadcast; |
| 92 | |
| 93 | /* Set from slave currently mastering the bus. */ |
| 94 | QEMUBH *bh; |
| 95 | }; |
| 96 | |
| 97 | I2CBus *i2c_init_bus(DeviceState *parent, const char *name); |
| 98 | int i2c_bus_busy(I2CBus *bus); |
| 99 | |
| 100 | /** |
| 101 | * i2c_start_transfer: start a transfer on an I2C bus. |
| 102 | * |
| 103 | * @bus: #I2CBus to be used |
| 104 | * @address: address of the slave |
| 105 | * @is_recv: indicates the transfer direction |
| 106 | * |
| 107 | * When @is_recv is a known boolean constant, use the |
| 108 | * i2c_start_recv() or i2c_start_send() helper instead. |
| 109 | * |
| 110 | * Returns: 0 on success, -1 on error |
| 111 | */ |
| 112 | int i2c_start_transfer(I2CBus *bus, uint8_t address, bool is_recv); |
| 113 | |
| 114 | /** |
| 115 | * i2c_start_recv: start a 'receive' transfer on an I2C bus. |
| 116 | * |
| 117 | * @bus: #I2CBus to be used |
| 118 | * @address: address of the slave |
| 119 | * |
| 120 | * Returns: 0 on success, -1 on error |
| 121 | */ |
| 122 | int i2c_start_recv(I2CBus *bus, uint8_t address); |
| 123 | |
| 124 | /** |
| 125 | * i2c_start_send: start a 'send' transfer on an I2C bus. |
| 126 | * |
| 127 | * @bus: #I2CBus to be used |
| 128 | * @address: address of the slave |
| 129 | * |
| 130 | * Returns: 0 on success, -1 on error |
| 131 | */ |
| 132 | int i2c_start_send(I2CBus *bus, uint8_t address); |
| 133 | |
| 134 | /** |
| 135 | * i2c_start_send_async: start an asynchronous 'send' transfer on an I2C bus. |
| 136 | * |
| 137 | * @bus: #I2CBus to be used |
| 138 | * @address: address of the slave |
| 139 | * |
| 140 | * Return: 0 on success, -1 on error |
| 141 | */ |
| 142 | int i2c_start_send_async(I2CBus *bus, uint8_t address); |
| 143 | |
| 144 | void i2c_schedule_pending_master(I2CBus *bus); |
| 145 | |
| 146 | void i2c_end_transfer(I2CBus *bus); |
| 147 | void i2c_nack(I2CBus *bus); |
| 148 | void i2c_ack(I2CBus *bus); |
| 149 | void i2c_bus_master(I2CBus *bus, QEMUBH *bh); |
| 150 | void i2c_bus_release(I2CBus *bus); |
| 151 | int i2c_send(I2CBus *bus, uint8_t data); |
| 152 | int i2c_send_async(I2CBus *bus, uint8_t data); |
| 153 | uint8_t i2c_recv(I2CBus *bus); |
| 154 | bool i2c_scan_bus(I2CBus *bus, uint8_t address, bool broadcast, |
| 155 | I2CNodeList *current_devs); |
| 156 | |
| 157 | /** |
| 158 | * Create an I2C slave device on the heap. |
| 159 | * @name: a device type name |
| 160 | * @addr: I2C address of the slave when put on a bus |
| 161 | * |
| 162 | * This only initializes the device state structure and allows |
| 163 | * properties to be set. Type @name must exist. The device still |
| 164 | * needs to be realized. See qdev-core.h. |
| 165 | */ |
| 166 | I2CSlave *i2c_slave_new(const char *name, uint8_t addr); |
| 167 | |
| 168 | /** |
| 169 | * Create and realize an I2C slave device on the heap. |
| 170 | * @bus: I2C bus to put it on |
| 171 | * @name: I2C slave device type name |
| 172 | * @addr: I2C address of the slave when put on a bus |
| 173 | * |
| 174 | * Create the device state structure, initialize it, put it on the |
| 175 | * specified @bus, and drop the reference to it (the device is realized). |
| 176 | */ |
| 177 | I2CSlave *i2c_slave_create_simple(I2CBus *bus, const char *name, uint8_t addr); |
| 178 | |
| 179 | /** |
| 180 | * Realize and drop a reference an I2C slave device |
| 181 | * @dev: I2C slave device to realize |
| 182 | * @bus: I2C bus to put it on |
| 183 | * @addr: I2C address of the slave on the bus |
| 184 | * @errp: pointer to NULL initialized error object |
| 185 | * |
| 186 | * Returns: %true on success, %false on failure. |
| 187 | * |
| 188 | * Call 'realize' on @dev, put it on the specified @bus, and drop the |
| 189 | * reference to it. |
| 190 | * |
| 191 | * This function is useful if you have created @dev via qdev_new(), |
| 192 | * i2c_slave_new() or i2c_slave_try_new() (which take a reference to |
| 193 | * the device it returns to you), so that you can set properties on it |
| 194 | * before realizing it. If you don't need to set properties then |
| 195 | * i2c_slave_create_simple() is probably better (as it does the create, |
| 196 | * init and realize in one step). |
| 197 | * |
| 198 | * If you are embedding the I2C slave into another QOM device and |
| 199 | * initialized it via some variant on object_initialize_child() then |
| 200 | * do not use this function, because that family of functions arrange |
| 201 | * for the only reference to the child device to be held by the parent |
| 202 | * via the child<> property, and so the reference-count-drop done here |
| 203 | * would be incorrect. (Instead you would want i2c_slave_realize(), |
| 204 | * which doesn't currently exist but would be trivial to create if we |
| 205 | * had any code that wanted it.) |
| 206 | */ |
| 207 | bool i2c_slave_realize_and_unref(I2CSlave *dev, I2CBus *bus, Error **errp); |
| 208 | |
| 209 | /** |
| 210 | * Set the I2C bus address of a slave device |
| 211 | * @dev: I2C slave device |
| 212 | * @address: I2C address of the slave when put on a bus |
| 213 | */ |
| 214 | void i2c_slave_set_address(I2CSlave *dev, uint8_t address); |
| 215 | |
| 216 | extern const VMStateDescription vmstate_i2c_slave; |
| 217 | |
| 218 | #define VMSTATE_I2C_SLAVE(_field, _state) { \ |
| 219 | .name = (stringify(_field)), \ |
| 220 | .size = sizeof(I2CSlave), \ |
| 221 | .vmsd = &vmstate_i2c_slave, \ |
| 222 | .flags = VMS_STRUCT, \ |
| 223 | .offset = vmstate_offset_value(_state, _field, I2CSlave), \ |
| 224 | } |
| 225 | |
| 226 | #endif |