[PATCH 5/9] I2C: Add smbus quick read/write helper function

From: Lan Tianyu
Date: Wed Apr 16 2014 - 09:26:47 EST


Add i2c_smbus_quick_write/read() helper function. These will be used
in the implementation of i2c ACPI address space handler.

Signed-off-by: Lan Tianyu <tianyu.lan@xxxxxxxxx>
---
drivers/i2c/i2c-core.c | 30 ++++++++++++++++++++++++++++++
include/linux/i2c.h | 2 ++
2 files changed, 32 insertions(+)

diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index 7c7f4b8..3bf0048 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -2162,6 +2162,36 @@ static int i2c_smbus_check_pec(u8 cpec, struct i2c_msg *msg)
}

/**
+ * i2c_smbus_quick_write - SMBus "quick write" protocol
+ * @client: Handle to slave device
+ *
+ * This executes the SMBus "quick write" protocol, returning negative errno
+ * else zero on success.
+ */
+s32 i2c_smbus_quick_write(const struct i2c_client *client)
+{
+ return i2c_smbus_xfer(client->adapter, client->addr, client->flags,
+ I2C_SMBUS_WRITE, 0,
+ I2C_SMBUS_QUICK, NULL);
+}
+EXPORT_SYMBOL_GPL(i2c_smbus_quick_write);
+
+/**
+ * i2c_smbus_quick_read - SMBus "quick read" protocol
+ * @client: Handle to slave device
+ *
+ * This executes the SMBus "quick read" protocol, returning negative errno
+ * else zero on success.
+ */
+s32 i2c_smbus_quick_read(const struct i2c_client *client)
+{
+ return i2c_smbus_xfer(client->adapter, client->addr, client->flags,
+ I2C_SMBUS_READ, 0,
+ I2C_SMBUS_QUICK, NULL);
+}
+EXPORT_SYMBOL_GPL(i2c_smbus_quick_read);
+
+/**
* i2c_smbus_read_byte - SMBus "receive byte" protocol
* @client: Handle to slave device
*
diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index b556e0a..3e6ea90 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -82,6 +82,8 @@ extern s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
/* Now follow the 'nice' access routines. These also document the calling
conventions of i2c_smbus_xfer. */

+extern s32 i2c_smbus_quick_write(const struct i2c_client *client);
+extern s32 i2c_smbus_quick_read(const struct i2c_client *client);
extern s32 i2c_smbus_read_byte(const struct i2c_client *client);
extern s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value);
extern s32 i2c_smbus_read_byte_data(const struct i2c_client *client,
--
1.8.4.rc0.1.g8f6a3e5.dirty

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