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Commit f4cdc319 authored by Eddie James's avatar Eddie James Committed by Wolfram Sang
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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: default avatarEddie James <eajames@linux.vnet.ibm.com>
Reviewed-by: default avatarAndy Shevchenko <andy.shevchenko@gmail.com>
Tested-by: default avatarJoel Stanley <joel@jms.id.au>
Signed-off-by: default avatarWolfram Sang <wsa@the-dreams.de>
parent 504b8277

drivers/i2c/busses/i2c-fsi.c

+12 −4
Original line number Diff line number Diff line
@@ -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);