i2c: i2c stack can probe()
One of a series of I2C infrastructure updates to support enumeration using
the standard Linux driver model.
This patch updates probe() and associated hotplug/coldplug support, but
not remove(). Nothing yet _uses_ it to create I2C devices, so those
hotplug/coldplug mechanisms will be the only externally visible change.
This patch will be an overall NOP since the I2C stack doesn't yet create
clients/devices except as part of binding them to legacy drivers.
Some code is moved earlier in the source code, helping group more of the
per-device infrastructure in one place and simplifying handling per-device
attributes.
Terminology being adopted: "legacy drivers" create devices (i2c_client)
themselves, while "new style" ones follow the driver model (the i2c_client
is handed to the probe routine). It's an either/or thing; the two models
don't mix, and drivers that try mixing them won't even be registered.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index 563c965..8dcccc0 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -113,7 +113,7 @@
* can be used by the driver to test if the bus meets its conditions
* & seek for the presence of the chip(s) it supports. If found, it
* registers the client(s) that are on the bus to the i2c admin. via
- * i2c_attach_client.
+ * i2c_attach_client. (LEGACY I2C DRIVERS ONLY)
*/
int (*attach_adapter)(struct i2c_adapter *);
int (*detach_adapter)(struct i2c_adapter *);
@@ -121,10 +121,16 @@
/* tells the driver that a client is about to be deleted & gives it
* the chance to remove its private data. Also, if the client struct
* has been dynamically allocated by the driver in the function above,
- * it must be freed here.
+ * it must be freed here. (LEGACY I2C DRIVERS ONLY)
*/
int (*detach_client)(struct i2c_client *);
+ /* Standard driver model interfaces, for "new style" i2c drivers.
+ * With the driver model, device enumeration is NEVER done by drivers;
+ * it's done by infrastructure. (NEW STYLE DRIVERS ONLY)
+ */
+ int (*probe)(struct i2c_client *);
+
/* driver model interfaces that don't relate to enumeration */
void (*shutdown)(struct i2c_client *);
int (*suspend)(struct i2c_client *, pm_message_t mesg);
@@ -148,6 +154,8 @@
* @name: Indicates the type of the device, usually a chip name that's
* generic enough to hide second-sourcing and compatible revisions.
* @dev: Driver model device node for the slave.
+ * @driver_name: Identifies new-style driver used with this device; also
+ * used as the module name for hotplug/coldplug modprobe support.
*
* An i2c_client identifies a single device (i.e. chip) connected to an
* i2c bus. The behaviour is defined by the routines of the driver.
@@ -163,6 +171,7 @@
int usage_count; /* How many accesses currently */
/* to the client */
struct device dev; /* the device structure */
+ char driver_name[KOBJ_NAME_LEN];
struct list_head list;
struct completion released;
};