[PATCH 1/3] i2c: Add slices for I2C adapters

[Sascha Hauer]

Add a slice for I2C adapters so that devices using I2C in the background
can check if a I2C bus is busy.

Signed-off-by: Sascha Hauer <s.hauer at pengutronix.de>
---
 drivers/i2c/i2c.c | 5 +++++
 include/i2c/i2c.h | 7 +++++++
 2 files changed, 12 insertions(+)

diff --git a/drivers/i2c/i2c.c b/drivers/i2c/i2c.c
index 300365bd1f..4d4a9a3948 100644
--- a/drivers/i2c/i2c.c
+++ b/drivers/i2c/i2c.c
@@ -23,6 +23,7 @@
 #include <init.h>
 #include <of.h>
 #include <gpio.h>
+#include <slice.h>
 
 #include <i2c/i2c.h>
 
@@ -62,6 +63,8 @@ int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
 	uint64_t start;
 	int ret, try;
 
+	slice_acquire(&adap->slice);
+
 	/*
 	 * REVISIT the fault reporting model here is weak:
 	 *
@@ -96,6 +99,8 @@ int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
 			break;
 	}
 
+	slice_release(&adap->slice);
+
 	return ret;
 }
 EXPORT_SYMBOL(i2c_transfer);
diff --git a/include/i2c/i2c.h b/include/i2c/i2c.h
index b1ab72850c..4fc278f800 100644
--- a/include/i2c/i2c.h
+++ b/include/i2c/i2c.h
@@ -18,6 +18,7 @@
 
 #include <driver.h>
 #include <init.h>
+#include <slice.h>
 #include <linux/types.h>
 
 struct i2c_adapter;
@@ -121,6 +122,7 @@ int i2c_generic_scl_recovery(struct i2c_adapter *adap);
  */
 struct i2c_adapter {
 	struct device		dev;	/* ptr to device */
+	struct slice		slice;
 	int			nr;	/* bus number */
 	int (*master_xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs, int num);
 	struct list_head	list;
@@ -318,6 +320,11 @@ static inline int i2c_adapter_id(struct i2c_adapter *adap)
 	return adap->nr;
 }
 
+static inline struct slice *i2c_client_slice(struct i2c_client *client)
+{
+	return &client->adapter->slice;
+}
+
 extern int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num);
 extern int i2c_master_send(struct i2c_client *client, const char *buf, int count);
 extern int i2c_master_recv(struct i2c_client *client, char *buf, int count);
-- 
2.39.2