i2c: apply address offset for slaves, too
authorWolfram Sang <wsa+renesas@sang-engineering.com>
Mon, 18 May 2015 19:09:12 +0000 (21:09 +0200)
committerWolfram Sang <wsa@the-dreams.de>
Mon, 24 Aug 2015 12:05:11 +0000 (14:05 +0200)
We want a separate address range for being an I2C slave. Add an offset
of 0x1000, so it can be combined with ten bit addresses as well. Add a
separate function to create the address value, we will need it later in
other places.

Tested-by: Andrey Danin <danindrey@mail.ru>
Acked-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
drivers/i2c/i2c-core.c

index 07a83f34ed58e710d829408a4dfc79bc76f89b4b..47dbe251474142ce72f59a5add9c883f815dea5d 100644 (file)
@@ -57,6 +57,9 @@
 #define CREATE_TRACE_POINTS
 #include <trace/events/i2c.h>
 
+#define I2C_ADDR_OFFSET_TEN_BIT        0xa000
+#define I2C_ADDR_OFFSET_SLAVE  0x1000
+
 /* core_lock protects i2c_adapter_idr, and guarantees
    that device detection, deletion of detected devices, and attach_adapter
    calls are serialized */
@@ -778,6 +781,21 @@ struct i2c_client *i2c_verify_client(struct device *dev)
 EXPORT_SYMBOL(i2c_verify_client);
 
 
+/* Return a unique address which takes the flags of the client into account */
+static unsigned short i2c_encode_flags_to_addr(struct i2c_client *client)
+{
+       unsigned short addr = client->addr;
+
+       /* For some client flags, add an arbitrary offset to avoid collisions */
+       if (client->flags & I2C_CLIENT_TEN)
+               addr |= I2C_ADDR_OFFSET_TEN_BIT;
+
+       if (client->flags & I2C_CLIENT_SLAVE)
+               addr |= I2C_ADDR_OFFSET_SLAVE;
+
+       return addr;
+}
+
 /* This is a permissive address validity check, I2C address map constraints
  * are purposely not enforced, except for the general call address. */
 static int i2c_check_client_addr_validity(const struct i2c_client *client)
@@ -923,10 +941,8 @@ static void i2c_dev_set_name(struct i2c_adapter *adap,
                return;
        }
 
-       /* For 10-bit clients, add an arbitrary offset to avoid collisions */
        dev_set_name(&client->dev, "%d-%04x", i2c_adapter_id(adap),
-                    client->addr | ((client->flags & I2C_CLIENT_TEN)
-                                    ? 0xa000 : 0));
+                    i2c_encode_flags_to_addr(client));
 }
 
 /**