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authorWolfram Sang <wsa+renesas@sang-engineering.com>2015-05-18 21:09:12 +0200
committerWolfram Sang <wsa@the-dreams.de>2015-08-24 14:05:11 +0200
commitda899f55b359225f85e154765baaddb13ec436ca (patch)
tree00d1db2a93b72e740a30d4127c6170ce6d1e829f
parenti2c: add a flag to mark clients as slaves (diff)
downloadlinux-da899f55b359225f85e154765baaddb13ec436ca.tar.xz
linux-da899f55b359225f85e154765baaddb13ec436ca.zip
i2c: apply address offset for slaves, too
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>
-rw-r--r--drivers/i2c/i2c-core.c22
1 files changed, 19 insertions, 3 deletions
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index 07a83f34ed58..47dbe2514741 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -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));
}
/**