include/linux/i2c-old.h

   1 #ifndef I2C_H
   2 #define I2C_H
   3
   4 /*
   5  * linux i2c interface.  Works a little bit like the scsi subsystem.
   6  * There are:
   7  *
   8  *     i2c          the basic control module        (like scsi_mod)
   9  *     bus driver   a driver with a i2c bus         (hostadapter driver)
  10  *     chip driver  a driver for a chip connected
  11  *                  to a i2c bus                    (cdrom/hd driver)
  12  *
  13  * A device will be attached to one bus and one chip driver.  Every chip
  14  * driver gets a unique ID.
  15  *
  16  * A chip driver can provide a ioctl-like callback for the
  17  * communication with other parts of the kernel (not every i2c chip is
  18  * useful without other devices, a TV card tuner for example).
  19  *
  20  * "i2c internal" parts of the structs: only the i2c module is allowed to
  21  * write to them, for others they are read-only.
  22  *
  23  */
  24
  25 #include <linux/version.h>
  26
  27 #define I2C_BUS_MAX       4    /* max # of bus drivers  */
  28 #define I2C_DRIVER_MAX    8    /* max # of chip drivers */
  29 #define I2C_DEVICE_MAX    8    /* max # if devices per bus/driver */
  30
  31 struct i2c_bus;
  32 struct i2c_driver;
  33 struct i2c_device;
  34
  35 #define I2C_DRIVERID_MSP3400             1
  36 #define I2C_DRIVERID_TUNER               2
  37 #define I2C_DRIVERID_VIDEOTEXT           3
  38 #define I2C_DRIVERID_VIDEODECODER        4
  39 #define I2C_DRIVERID_VIDEOENCODER        5
  40
  41 #define I2C_BUSID_BT848         1       /* I2C bus on a BT848 */
  42 #define I2C_BUSID_PARPORT       2       /* Bit banging on a parallel port */
  43 #define I2C_BUSID_BUZ           3
  44 #define I2C_BUSID_ZORAN         4
  45 #define I2C_BUSID_CYBER2000     5
  46
  47 /*
  48  * struct for a driver for a i2c chip (tuner, soundprocessor,
  49  * videotext, ... ).
  50  *
  51  * a driver will register within the i2c module.  The i2c module will
  52  * callback the driver (i2c_attach) for every device it finds on a i2c
  53  * bus at the specified address.  If the driver decides to "accept"
  54  * the, device, it must return a struct i2c_device, and NULL
  55  * otherwise.
  56  *
  57  * i2c_detach = i2c_attach ** -1
  58  *
  59  * i2c_command will be used to pass commands to the driver in a
  60  * ioctl-line manner.
  61  *
  62  */
  63
  64 struct i2c_driver
  65 {
  66     char           name[32];         /* some useful label         */
  67     int            id;               /* device type ID            */
  68     unsigned char  addr_l, addr_h;   /* address range of the chip */
  69
  70     int (*attach)(struct i2c_device *device);
  71     int (*detach)(struct i2c_device *device);
  72     int (*command)(struct i2c_device *device,unsigned int cmd, void *arg);
  73
  74     /* i2c internal */
  75     struct i2c_device   *devices[I2C_DEVICE_MAX];
  76     int                 devcount;
  77 };
  78
  79
  80 /*
  81  * this holds the informations about a i2c bus available in the system.
  82  *
  83  * a chip with a i2c bus interface (like bt848) registers the bus within
  84  * the i2c module. This struct provides functions to access the i2c bus.
  85  *
  86  * One must hold the spinlock to access the i2c bus (XXX: is the irqsave
  87  * required? Maybe better use a semaphore?).
  88  * [-AC-] having a spinlock_irqsave is only needed if we have drivers wishing
  89  *        to bang their i2c bus from an interrupt.
  90  *
  91  * attach/detach_inform is a callback to inform the bus driver about
  92  * attached chip drivers.
  93  *
  94  */
  95
  96 /* needed: unsigned long flags */
  97
  98 #if LINUX_VERSION_CODE >= 0x020100
  99 # if 0
 100 #  define LOCK_FLAGS unsigned long flags;
 101 #  define LOCK_I2C_BUS(bus)    spin_lock_irqsave(&(bus->bus_lock),flags);
 102 #  define UNLOCK_I2C_BUS(bus)  spin_unlock_irqrestore(&(bus->bus_lock),flags);
 103 # else
 104 #  define LOCK_FLAGS
 105 #  define LOCK_I2C_BUS(bus)    spin_lock(&(bus->bus_lock));
 106 #  define UNLOCK_I2C_BUS(bus)  spin_unlock(&(bus->bus_lock));
 107 # endif
 108 #else
 109 # define LOCK_FLAGS unsigned long flags;
 110 # define LOCK_I2C_BUS(bus)    { save_flags(flags); cli(); }
 111 # define UNLOCK_I2C_BUS(bus)  { restore_flags(flags);     }
 112 #endif
 113
 114 struct i2c_bus
 115 {
 116         char  name[32];         /* some useful label */
 117         int   id;
 118         void  *data;            /* free for use by the bus driver */
 119
 120 #if LINUX_VERSION_CODE >= 0x020100
 121         spinlock_t bus_lock;
 122 #endif
 123
 124         /* attach/detach inform callbacks */
 125         void    (*attach_inform)(struct i2c_bus *bus, int id);
 126         void    (*detach_inform)(struct i2c_bus *bus, int id);
 127
 128         /* Software I2C */
 129         void    (*i2c_setlines)(struct i2c_bus *bus, int ctrl, int data);
 130         int     (*i2c_getdataline)(struct i2c_bus *bus);
 131
 132         /* Hardware I2C */
 133         int     (*i2c_read)(struct i2c_bus *bus, unsigned char addr);
 134         int     (*i2c_write)(struct i2c_bus *bus, unsigned char addr,
 135                          unsigned char b1, unsigned char b2, int both);
 136
 137         /* internal data for i2c module */
 138         struct i2c_device   *devices[I2C_DEVICE_MAX];
 139         int                 devcount;
 140 };
 141
 142
 143 /*
 144  *      This holds per-device data for a i2c device
 145  */
 146
 147 struct i2c_device
 148 {
 149         char           name[32];         /* some useful label */
 150         void           *data;            /* free for use by the chip driver */
 151         unsigned char  addr;             /* chip addr */
 152
 153         /* i2c internal */
 154         struct i2c_bus     *bus;
 155         struct i2c_driver  *driver;
 156 };
 157
 158
 159 /* ------------------------------------------------------------------- */
 160 /* i2c module functions                                                */
 161
 162 /* register/unregister a i2c bus */
 163 int i2c_register_bus(struct i2c_bus *bus);
 164 int i2c_unregister_bus(struct i2c_bus *bus);
 165
 166 /* register/unregister a chip driver */
 167 int i2c_register_driver(struct i2c_driver *driver);
 168 int i2c_unregister_driver(struct i2c_driver *driver);
 169
 170 /* send a command to a chip using the ioctl-like callback interface */
 171 int i2c_control_device(struct i2c_bus *bus, int id,
 172                        unsigned int cmd, void *arg);
 173
 174 /* i2c bus access functions */
 175 void    i2c_start(struct i2c_bus *bus);
 176 void    i2c_stop(struct i2c_bus *bus);
 177 void    i2c_one(struct i2c_bus *bus);
 178 void    i2c_zero(struct i2c_bus *bus);
 179 int     i2c_ack(struct i2c_bus *bus);
 180
 181 int     i2c_sendbyte(struct i2c_bus *bus,unsigned char data,int wait_for_ack);
 182 unsigned char i2c_readbyte(struct i2c_bus *bus,int last);
 183
 184 /* i2c (maybe) hardware functions */
 185 int     i2c_read(struct i2c_bus *bus, unsigned char addr);
 186 int     i2c_write(struct i2c_bus *bus, unsigned char addr,
 187                   unsigned char b1, unsigned char b2, int both);
 188
 189 int     i2c_init(void);
 190 #endif /* I2C_H */