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path: root/drivers/i2c/busses/i2c-rcar.c
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Diffstat (limited to 'drivers/i2c/busses/i2c-rcar.c')
-rw-r--r--drivers/i2c/busses/i2c-rcar.c37
1 files changed, 31 insertions, 6 deletions
diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c
index f3c7139dfa25..1cc146cfc1f3 100644
--- a/drivers/i2c/busses/i2c-rcar.c
+++ b/drivers/i2c/busses/i2c-rcar.c
@@ -34,6 +34,7 @@
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/slab.h>
+#include <linux/spinlock.h>
/* register offsets */
#define ICSCR 0x00 /* slave ctrl */
@@ -95,6 +96,7 @@ struct rcar_i2c_priv {
struct i2c_msg *msg;
struct clk *clk;
+ spinlock_t lock;
wait_queue_head_t wait;
int pos;
@@ -365,20 +367,20 @@ static irqreturn_t rcar_i2c_irq(int irq, void *ptr)
struct rcar_i2c_priv *priv = ptr;
u32 msr;
+ /*-------------- spin lock -----------------*/
+ spin_lock(&priv->lock);
+
msr = rcar_i2c_read(priv, ICMSR);
+ /* Only handle interrupts that are currently enabled */
+ msr &= rcar_i2c_read(priv, ICMIER);
+
/* Arbitration lost */
if (msr & MAL) {
rcar_i2c_flags_set(priv, (ID_DONE | ID_ARBLOST));
goto out;
}
- /* Stop */
- if (msr & MST) {
- rcar_i2c_flags_set(priv, ID_DONE);
- goto out;
- }
-
/* Nack */
if (msr & MNR) {
/* go to stop phase */
@@ -388,6 +390,12 @@ static irqreturn_t rcar_i2c_irq(int irq, void *ptr)
goto out;
}
+ /* Stop */
+ if (msr & MST) {
+ rcar_i2c_flags_set(priv, ID_DONE);
+ goto out;
+ }
+
if (rcar_i2c_is_recv(priv))
rcar_i2c_flags_set(priv, rcar_i2c_irq_recv(priv, msr));
else
@@ -400,6 +408,9 @@ out:
wake_up(&priv->wait);
}
+ spin_unlock(&priv->lock);
+ /*-------------- spin unlock -----------------*/
+
return IRQ_HANDLED;
}
@@ -409,14 +420,21 @@ static int rcar_i2c_master_xfer(struct i2c_adapter *adap,
{
struct rcar_i2c_priv *priv = i2c_get_adapdata(adap);
struct device *dev = rcar_i2c_priv_to_dev(priv);
+ unsigned long flags;
int i, ret, timeout;
pm_runtime_get_sync(dev);
+ /*-------------- spin lock -----------------*/
+ spin_lock_irqsave(&priv->lock, flags);
+
rcar_i2c_init(priv);
/* start clock */
rcar_i2c_write(priv, ICCCR, priv->icccr);
+ spin_unlock_irqrestore(&priv->lock, flags);
+ /*-------------- spin unlock -----------------*/
+
ret = rcar_i2c_bus_barrier(priv);
if (ret < 0)
goto out;
@@ -428,6 +446,9 @@ static int rcar_i2c_master_xfer(struct i2c_adapter *adap,
break;
}
+ /*-------------- spin lock -----------------*/
+ spin_lock_irqsave(&priv->lock, flags);
+
/* init each data */
priv->msg = &msgs[i];
priv->pos = 0;
@@ -437,6 +458,9 @@ static int rcar_i2c_master_xfer(struct i2c_adapter *adap,
ret = rcar_i2c_prepare_msg(priv);
+ spin_unlock_irqrestore(&priv->lock, flags);
+ /*-------------- spin unlock -----------------*/
+
if (ret < 0)
break;
@@ -540,6 +564,7 @@ static int rcar_i2c_probe(struct platform_device *pdev)
irq = platform_get_irq(pdev, 0);
init_waitqueue_head(&priv->wait);
+ spin_lock_init(&priv->lock);
adap = &priv->adap;
adap->nr = pdev->id;