From f4cdc319cff88eb83564a5466c15af8128dd8284 Mon Sep 17 00:00:00 2001 From: Eddie James Date: Tue, 17 Jul 2018 10:31:04 -0500 Subject: [PATCH] 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 Reviewed-by: Andy Shevchenko Tested-by: Joel Stanley Signed-off-by: Wolfram Sang --- drivers/i2c/busses/i2c-fsi.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) diff --git a/drivers/i2c/busses/i2c-fsi.c b/drivers/i2c/busses/i2c-fsi.c index 45a6ebd..27d74a9 100644 --- a/drivers/i2c/busses/i2c-fsi.c +++ b/drivers/i2c/busses/i2c-fsi.c @@ -21,6 +21,7 @@ #include #include #include +#include #include #include @@ -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); -- 2.7.4