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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>
hifive-unleashed-5.1
Eddie James 2018-07-17 10:31:04 -05:00 committed by Wolfram Sang
parent 504b82773c
commit f4cdc319cf
1 changed files with 12 additions and 4 deletions
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16
drivers/i2c/busses/i2c-fsi.c
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@ -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);