i2c: Add detection capability to new-style drivers

[linux-2.6-omap-h63xx.git] / include / linux / i2c.h

diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index 8dc7301321926f6f4a6e9454dcd50d9aa9d1722f..08be0d21864c6fcd81dd667baee289b81edf20e5 100644 (file)
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -35,6 +35,8 @@
 #include <linux/sched.h>       /* for completion */
 #include <linux/mutex.h>
 
+extern struct bus_type i2c_bus_type;
+
 /* --- General options ------------------------------------------------        */
 
 struct i2c_msg;
@@ -43,6 +45,7 @@ struct i2c_adapter;
 struct i2c_client;
 struct i2c_driver;
 union i2c_smbus_data;
+struct i2c_board_info;
 
 /*
  * The master routines are the ones normally used to transmit data to devices
@@ -69,9 +72,8 @@ extern s32 i2c_smbus_xfer (struct i2c_adapter * adapter, u16 addr,
                            union i2c_smbus_data * data);
 
 /* Now follow the 'nice' access routines. These also document the calling
-   conventions of smbus_access. */
+   conventions of i2c_smbus_xfer. */
 
-extern s32 i2c_smbus_write_quick(struct i2c_client * client, u8 value);
 extern s32 i2c_smbus_read_byte(struct i2c_client * client);
 extern s32 i2c_smbus_write_byte(struct i2c_client * client, u8 value);
 extern s32 i2c_smbus_read_byte_data(struct i2c_client * client, u8 command);
@@ -93,15 +95,33 @@ extern s32 i2c_smbus_write_i2c_block_data(struct i2c_client * client,
                                          u8 command, u8 length,
                                          const u8 *values);
 
-/*
- * A driver is capable of handling one or more physical devices present on
- * I2C adapters. This information is used to inform the driver of adapter
- * events.
+/**
+ * struct i2c_driver - represent an I2C device driver
+ * @class: What kind of i2c device we instantiate (for detect)
+ * @detect: Callback for device detection
+ * @address_data: The I2C addresses to probe, ignore or force (for detect)
+ * @clients: List of detected clients we created (for i2c-core use only)
  *
  * The driver.owner field should be set to the module owner of this driver.
  * The driver.name field should be set to the name of this driver.
+ *
+ * For automatic device detection, both @detect and @address_data must
+ * be defined. @class should also be set, otherwise only devices forced
+ * with module parameters will be created. The detect function must
+ * fill at least the name field of the i2c_board_info structure it is
+ * handed upon successful detection, and possibly also the flags field.
+ *
+ * If @detect is missing, the driver will still work fine for enumerated
+ * devices. Detected devices simply won't be supported. This is expected
+ * for the many I2C/SMBus devices which can't be detected reliably, and
+ * the ones which can always be enumerated in practice.
+ *
+ * The i2c_client structure which is handed to the @detect callback is
+ * not a real i2c_client. It is initialized just enough so that you can
+ * call i2c_smbus_read_byte_data and friends on it. Don't do anything
+ * else with it. In particular, calling dev_dbg and friends on it is
+ * not allowed.
  */
-
 struct i2c_driver {
        int id;
        unsigned int class;
@@ -141,6 +161,11 @@ struct i2c_driver {
 
        struct device_driver driver;
        const struct i2c_device_id *id_table;
+
+       /* Device detection callback for automatic device creation */
+       int (*detect)(struct i2c_client *, int kind, struct i2c_board_info *);
+       const struct i2c_client_address_data *address_data;
+       struct list_head clients;
 };
 #define to_i2c_driver(d) container_of(d, struct i2c_driver, driver)
 
@@ -156,6 +181,7 @@ struct i2c_driver {
  * @dev: Driver model device node for the slave.
  * @irq: indicates the IRQ generated by this device (if any)
  * @list: list of active/busy clients (DEPRECATED)
+ * @detected: member of an i2c_driver.clients list
  * @released: used to synchronize client releases & detaches and references
  *
  * An i2c_client identifies a single device (i.e. chip) connected to an
@@ -173,6 +199,7 @@ struct i2c_client {
        struct device dev;              /* the device structure         */
        int irq;                        /* irq issued by device         */
        struct list_head list;          /* DEPRECATED */
+       struct list_head detected;
        struct completion released;
 };
 #define to_i2c_client(d) container_of(d, struct i2c_client, dev)
@@ -350,10 +377,11 @@ static inline void i2c_set_adapdata (struct i2c_adapter *dev, void *data)
 #define I2C_CLASS_HWMON                (1<<0)  /* lm_sensors, ... */
 #define I2C_CLASS_TV_ANALOG    (1<<1)  /* bttv + friends */
 #define I2C_CLASS_TV_DIGITAL   (1<<2)  /* dvb cards */
-#define I2C_CLASS_DDC          (1<<3)  /* i2c-matroxfb ? */
+#define I2C_CLASS_DDC          (1<<3)  /* DDC bus on graphics adapters */
 #define I2C_CLASS_CAM_ANALOG   (1<<4)  /* camera with analog CCD */
 #define I2C_CLASS_CAM_DIGITAL  (1<<5)  /* most webcams */
 #define I2C_CLASS_SOUND                (1<<6)  /* sound devices */
+#define I2C_CLASS_SPD          (1<<7)  /* SPD EEPROMs and similar */
 #define I2C_CLASS_ALL          (UINT_MAX) /* all of the above */
 
 /* i2c_client_address_data is the struct for holding default client
@@ -537,7 +565,7 @@ union i2c_smbus_data {
                               /* and one more for user-space compatibility */
 };
 
-/* smbus_access read or write markers */
+/* i2c_smbus_xfer read or write markers */
 #define I2C_SMBUS_READ 1
 #define I2C_SMBUS_WRITE        0