root/include/linux/i2c-algo-pca.h

#ifndef _LINUX_I2C_ALGO_PCA_H
#define _LINUX_I2C_ALGO_PCA_H

/* Clock speeds for the bus */
#define I2C_PCA_CON_330kHz      0x00
#define I2C_PCA_CON_288kHz      0x01
#define I2C_PCA_CON_217kHz      0x02
#define I2C_PCA_CON_146kHz      0x03
#define I2C_PCA_CON_88kHz       0x04
#define I2C_PCA_CON_59kHz       0x05
#define I2C_PCA_CON_44kHz       0x06
#define I2C_PCA_CON_36kHz       0x07

/* PCA9564 registers */
#define I2C_PCA_STA             0x00 /* STATUS  Read Only  */
#define I2C_PCA_TO              0x00 /* TIMEOUT Write Only */
#define I2C_PCA_DAT             0x01 /* DATA    Read/Write */
#define I2C_PCA_ADR             0x02 /* OWN ADR Read/Write */
#define I2C_PCA_CON             0x03 /* CONTROL Read/Write */

#define I2C_PCA_CON_AA          0x80 /* Assert Acknowledge */
#define I2C_PCA_CON_ENSIO       0x40 /* Enable */
#define I2C_PCA_CON_STA         0x20 /* Start */
#define I2C_PCA_CON_STO         0x10 /* Stop */
#define I2C_PCA_CON_SI          0x08 /* Serial Interrupt */
#define I2C_PCA_CON_CR          0x07 /* Clock Rate (MASK) */

struct i2c_algo_pca_data {
        void                            *data;  /* private low level data */
        void (*write_byte)              (void *data, int reg, int val);
        int  (*read_byte)               (void *data, int reg);
        int  (*wait_for_completion)     (void *data);
        void (*reset_chip)              (void *data);
        /* i2c_clock values are defined in linux/i2c-algo-pca.h */
        unsigned int                    i2c_clock;
};

int i2c_pca_add_bus(struct i2c_adapter *);
int i2c_pca_add_numbered_bus(struct i2c_adapter *);

#endif /* _LINUX_I2C_ALGO_PCA_H */