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i2c.h

#ifndef __SOUND_I2C_H
#define __SOUND_I2C_H

/*
 *
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 *
 *
 */

typedef struct _snd_i2c_device snd_i2c_device_t;
typedef struct _snd_i2c_bus snd_i2c_bus_t;

#define SND_I2C_DEVICE_ADDRTEN      (1<<0)      /* 10-bit I2C address */

struct _snd_i2c_device {
      struct list_head list;
      snd_i2c_bus_t *bus;     /* I2C bus */
      char name[32];          /* some useful device name */
      unsigned short flags;   /* device flags */
      unsigned short addr;    /* device address (might be 10-bit) */
      unsigned long private_value;
      void *private_data;
      void (*private_free)(snd_i2c_device_t *device);
};

#define snd_i2c_device(n) list_entry(n, snd_i2c_device_t, list)

typedef struct _snd_i2c_bit_ops {
      void (*start)(snd_i2c_bus_t *bus);  /* transfer start */
      void (*stop)(snd_i2c_bus_t *bus);   /* transfer stop */
      void (*direction)(snd_i2c_bus_t *bus, int clock, int data);  /* set line direction (0 = write, 1 = read) */
      void (*setlines)(snd_i2c_bus_t *bus, int clock, int data);
      int (*getclock)(snd_i2c_bus_t *bus);
      int (*getdata)(snd_i2c_bus_t *bus, int ack);
} snd_i2c_bit_ops_t;

typedef struct _snd_i2c_ops {
      int (*sendbytes)(snd_i2c_device_t *device, unsigned char *bytes, int count);
      int (*readbytes)(snd_i2c_device_t *device, unsigned char *bytes, int count);
      int (*probeaddr)(snd_i2c_bus_t *bus, unsigned short addr);
} snd_i2c_ops_t;

struct _snd_i2c_bus {
      snd_card_t *card; /* card which I2C belongs to */
      char name[32];          /* some useful label */

      struct semaphore lock_mutex;

      snd_i2c_bus_t *master;  /* master bus when SCK/SCL is shared */
      struct list_head buses; /* master: slave buses sharing SCK/SCL, slave: link list */

      struct list_head devices; /* attached devices to this bus */

      union {
            snd_i2c_bit_ops_t *bit;
            void *ops;
      } hw_ops;         /* lowlevel operations */
      snd_i2c_ops_t *ops;     /* midlevel operations */

      unsigned long private_value;
      void *private_data;
      void (*private_free)(snd_i2c_bus_t *bus);
};

#define snd_i2c_slave_bus(n) list_entry(n, snd_i2c_bus_t, buses)

int snd_i2c_bus_create(snd_card_t *card, const char *name, snd_i2c_bus_t *master, snd_i2c_bus_t **ri2c);
int snd_i2c_device_create(snd_i2c_bus_t *bus, const char *name, unsigned char addr, snd_i2c_device_t **rdevice);
int snd_i2c_device_free(snd_i2c_device_t *device);

static inline void snd_i2c_lock(snd_i2c_bus_t *bus) {
      if (bus->master)
            down(&bus->master->lock_mutex);
      else
            down(&bus->lock_mutex);
}
static inline void snd_i2c_unlock(snd_i2c_bus_t *bus) {
      if (bus->master)
            up(&bus->master->lock_mutex);
      else
            up(&bus->lock_mutex);
}

int snd_i2c_sendbytes(snd_i2c_device_t *device, unsigned char *bytes, int count);
int snd_i2c_readbytes(snd_i2c_device_t *device, unsigned char *bytes, int count);
int snd_i2c_probeaddr(snd_i2c_bus_t *bus, unsigned short addr);

#endif /* __SOUND_I2C_H */

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