i2c.h

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#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
 *
 *
 */

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

struct snd_i2c_device {
    struct list_head list;
    struct snd_i2c_bus *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)(struct snd_i2c_device *device);
};

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

struct snd_i2c_bit_ops {
    void (*start)(struct snd_i2c_bus *bus); /* transfer start */
    void (*stop)(struct snd_i2c_bus *bus);  /* transfer stop */
    void (*direction)(struct snd_i2c_bus *bus, int clock, int data);  /* set line direction (0 = write, 1 = read) */
    void (*setlines)(struct snd_i2c_bus *bus, int clock, int data);
    int (*getclock)(struct snd_i2c_bus *bus);
    int (*getdata)(struct snd_i2c_bus *bus, int ack);
};

struct snd_i2c_ops {
    int (*sendbytes)(struct snd_i2c_device *device, unsigned char *bytes, int count);
    int (*readbytes)(struct snd_i2c_device *device, unsigned char *bytes, int count);
    int (*probeaddr)(struct snd_i2c_bus *bus, unsigned short addr);
};

struct snd_i2c_bus {
    struct snd_card *card;  /* card which I2C belongs to */
    char name[32];      /* some useful label */

    struct mutex lock_mutex;

    struct snd_i2c_bus *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 {
        struct snd_i2c_bit_ops *bit;
        void *ops;
    } hw_ops;       /* lowlevel operations */
    struct snd_i2c_ops *ops;    /* midlevel operations */

    unsigned long private_value;
    void *private_data;
    void (*private_free)(struct snd_i2c_bus *bus);
};

#define snd_i2c_slave_bus(n) list_entry(n, struct snd_i2c_bus, buses)

int snd_i2c_bus_create(struct snd_card *card, const char *name,
               struct snd_i2c_bus *master, struct snd_i2c_bus **ri2c);
int snd_i2c_device_create(struct snd_i2c_bus *bus, const char *name,
              unsigned char addr, struct snd_i2c_device **rdevice);
int snd_i2c_device_free(struct snd_i2c_device *device);

static inline void snd_i2c_lock(struct snd_i2c_bus *bus)
{
    if (bus->master)
        mutex_lock(&bus->master->lock_mutex);
    else
        mutex_lock(&bus->lock_mutex);
}

static inline void snd_i2c_unlock(struct snd_i2c_bus *bus)
{
    if (bus->master)
        mutex_unlock(&bus->master->lock_mutex);
    else
        mutex_unlock(&bus->lock_mutex);
}

int snd_i2c_sendbytes(struct snd_i2c_device *device, unsigned char *bytes, int count);
int snd_i2c_readbytes(struct snd_i2c_device *device, unsigned char *bytes, int count);
int snd_i2c_probeaddr(struct snd_i2c_bus *bus, unsigned short addr);

#endif /* __SOUND_I2C_H */