int speed_hz;
};
+/*
+ * Not all of these flags are implemented in the U-Boot API
+ */
+enum dm_i2c_msg_flags {
+ I2C_M_TEN = 0x0010, /* ten-bit chip address */
+ I2C_M_RD = 0x0001, /* read data, from slave to master */
+ I2C_M_STOP = 0x8000, /* send stop after this message */
+ I2C_M_NOSTART = 0x4000, /* no start before this message */
+ I2C_M_REV_DIR_ADDR = 0x2000, /* invert polarity of R/W bit */
+ I2C_M_IGNORE_NAK = 0x1000, /* continue after NAK */
+ I2C_M_NO_RD_ACK = 0x0800, /* skip the Ack bit on reads */
+ I2C_M_RECV_LEN = 0x0400, /* length is first received byte */
+};
+
+/**
+ * struct i2c_msg - an I2C message
+ *
+ * @addr: Slave address
+ * @flags: Flags (see enum dm_i2c_msg_flags)
+ * @len: Length of buffer in bytes, may be 0 for a probe
+ * @buf: Buffer to send/receive, or NULL if no data
+ */
+struct i2c_msg {
+ uint addr;
+ uint flags;
+ uint len;
+ u8 *buf;
+};
+
+/**
+ * struct i2c_msg_list - a list of I2C messages
+ *
+ * This is called i2c_rdwr_ioctl_data in Linux but the name does not seem
+ * appropriate in U-Boot.
+ *
+ * @msg: Pointer to i2c_msg array
+ * @nmsgs: Number of elements in the array
+ */
+struct i2c_msg_list {
+ struct i2c_msg *msgs;
+ uint nmsgs;
+};
+
/**
* dm_i2c_read() - read bytes from an I2C chip
*
*
* This reads a single value from the given address in an I2C chip
*
+ * @dev: Device to use for transfer
* @addr: Address to read from
* @return value read, or -ve on error
*/
*
* This writes a single value to the given address in an I2C chip
*
+ * @dev: Device to use for transfer
* @addr: Address to write to
* @val: Value to write (normally a byte)
* @return 0 on success, -ve on error
*/
int dm_i2c_reg_write(struct udevice *dev, uint offset, unsigned int val);
+/**
+ * dm_i2c_xfer() - Transfer messages over I2C
+ *
+ * This transfers a raw message. It is best to use dm_i2c_reg_read/write()
+ * instead.
+ *
+ * @dev: Device to use for transfer
+ * @msg: List of messages to transfer
+ * @nmsgs: Number of messages to transfer
+ * @return 0 on success, -ve on error
+ */
+int dm_i2c_xfer(struct udevice *dev, struct i2c_msg *msg, int nmsgs);
+
/**
* dm_i2c_set_bus_speed() - set the speed of a bus
*
#endif
-/*
- * Not all of these flags are implemented in the U-Boot API
- */
-enum dm_i2c_msg_flags {
- I2C_M_TEN = 0x0010, /* ten-bit chip address */
- I2C_M_RD = 0x0001, /* read data, from slave to master */
- I2C_M_STOP = 0x8000, /* send stop after this message */
- I2C_M_NOSTART = 0x4000, /* no start before this message */
- I2C_M_REV_DIR_ADDR = 0x2000, /* invert polarity of R/W bit */
- I2C_M_IGNORE_NAK = 0x1000, /* continue after NAK */
- I2C_M_NO_RD_ACK = 0x0800, /* skip the Ack bit on reads */
- I2C_M_RECV_LEN = 0x0400, /* length is first received byte */
-};
-
-/**
- * struct i2c_msg - an I2C message
- *
- * @addr: Slave address
- * @flags: Flags (see enum dm_i2c_msg_flags)
- * @len: Length of buffer in bytes, may be 0 for a probe
- * @buf: Buffer to send/receive, or NULL if no data
- */
-struct i2c_msg {
- uint addr;
- uint flags;
- uint len;
- u8 *buf;
-};
-
-/**
- * struct i2c_msg_list - a list of I2C messages
- *
- * This is called i2c_rdwr_ioctl_data in Linux but the name does not seem
- * appropriate in U-Boot.
- *
- * @msg: Pointer to i2c_msg array
- * @nmsgs: Number of elements in the array
- */
-struct i2c_msg_list {
- struct i2c_msg *msgs;
- uint nmsgs;
-};
-
/**
* struct dm_i2c_ops - driver operations for I2C uclass
*
#define i2c_get_ops(dev) ((struct dm_i2c_ops *)(dev)->driver->ops)
+/**
+ * struct i2c_mux_ops - operations for an I2C mux
+ *
+ * The current mux state is expected to be stored in the mux itself since
+ * it is the only thing that knows how to make things work. The mux can
+ * record the current state and then avoid switching unless it is necessary.
+ * So select() can be skipped if the mux is already in the correct state.
+ * Also deselect() can be made a nop if required.
+ */
+struct i2c_mux_ops {
+ /**
+ * select() - select one of of I2C buses attached to a mux
+ *
+ * This will be called when there is no bus currently selected by the
+ * mux. This method does not need to deselect the old bus since
+ * deselect() will be already have been called if necessary.
+ *
+ * @mux: Mux device
+ * @bus: I2C bus to select
+ * @channel: Channel number correponding to the bus to select
+ * @return 0 if OK, -ve on error
+ */
+ int (*select)(struct udevice *mux, struct udevice *bus, uint channel);
+
+ /**
+ * deselect() - select one of of I2C buses attached to a mux
+ *
+ * This is used to deselect the currently selected I2C bus.
+ *
+ * @mux: Mux device
+ * @bus: I2C bus to deselect
+ * @channel: Channel number correponding to the bus to deselect
+ * @return 0 if OK, -ve on error
+ */
+ int (*deselect)(struct udevice *mux, struct udevice *bus, uint channel);
+};
+
+#define i2c_mux_get_ops(dev) ((struct i2c_mux_ops *)(dev)->driver->ops)
+
/**
* i2c_get_chip() - get a device to use to access a chip on a bus
*
projects / karo-tx-uboot.git / blobdiff