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authorEddie James <eajames@linux.vnet.ibm.com>2018-07-17 10:31:04 -0500
committerWolfram Sang <wsa@the-dreams.de>2018-07-21 00:07:09 +0200
commitf4cdc319cff88eb83564a5466c15af8128dd8284 (patch)
treeee489452736ba045c38da354338f1b632ba34096 /drivers/i2c/busses
parent504b82773c074e88423e17b9a069ac9a07df02d6 (diff)
downloadlinux-stericsson-f4cdc319cff88eb83564a5466c15af8128dd8284.tar.gz
i2c: fsi: Add I2C master locking
Since there are many ports per master, each with it's own adapter and chardev, we need some locking to prevent transfers from changing the master state while other transfers are in progress. Signed-off-by: Eddie James <eajames@linux.vnet.ibm.com> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Tested-by: Joel Stanley <joel@jms.id.au> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Diffstat (limited to 'drivers/i2c/busses')
-rw-r--r--drivers/i2c/busses/i2c-fsi.c16
1 files changed, 12 insertions, 4 deletions
diff --git a/drivers/i2c/busses/i2c-fsi.c b/drivers/i2c/busses/i2c-fsi.c
index 45a6ebdeaa13..27d74a944c72 100644
--- a/drivers/i2c/busses/i2c-fsi.c
+++ b/drivers/i2c/busses/i2c-fsi.c
@@ -21,6 +21,7 @@
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/module.h>
+#include <linux/mutex.h>
#include <linux/of.h>
#include <linux/slab.h>
@@ -148,6 +149,7 @@ struct fsi_i2c_master {
struct fsi_device *fsi;
u8 fifo_size;
struct list_head ports;
+ struct mutex lock;
};
struct fsi_i2c_port {
@@ -486,11 +488,14 @@ static int fsi_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
int i, rc;
unsigned long start_time;
struct fsi_i2c_port *port = adap->algo_data;
+ struct fsi_i2c_master *master = port->master;
struct i2c_msg *msg;
+ mutex_lock(&master->lock);
+
rc = fsi_i2c_set_port(port);
if (rc)
- return rc;
+ goto unlock;
for (i = 0; i < num; i++) {
msg = msgs + i;
@@ -498,15 +503,17 @@ static int fsi_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
rc = fsi_i2c_start(port, msg, i == num - 1);
if (rc)
- return rc;
+ goto unlock;
rc = fsi_i2c_wait(port, msg,
adap->timeout - (jiffies - start_time));
if (rc)
- return rc;
+ goto unlock;
}
- return num;
+unlock:
+ mutex_unlock(&master->lock);
+ return rc ? : num;
}
static u32 fsi_i2c_functionality(struct i2c_adapter *adap)
@@ -532,6 +539,7 @@ static int fsi_i2c_probe(struct device *dev)
if (!i2c)
return -ENOMEM;
+ mutex_init(&i2c->lock);
i2c->fsi = to_fsi_dev(dev);
INIT_LIST_HEAD(&i2c->ports);