i2c: xiic: Replace spinlock with mutex

All protected sections are only called from sleep-able context, so there is
no need to use a spinlock.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Reviewed-by: Shubhrajyoti Datta <shubhraj@xilinx.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

drivers/i2c/busses/i2c-xiic.c

@@ -70,7 +70,7 @@ struct xiic_i2c {
 	wait_queue_head_t	wait;
 	struct i2c_adapter	adap;
 	struct i2c_msg		*tx_msg;
-	spinlock_t		lock;
+	struct mutex		lock;
 	unsigned int		tx_pos;
 	unsigned int		nmsgs;
 	enum xilinx_i2c_state	state;
@@ -369,7 +369,7 @@ static irqreturn_t xiic_process(int irq, void *dev_id)
 	 * To find which interrupts are pending; AND interrupts pending with
 	 * interrupts masked.
 	 */
-	spin_lock(&i2c->lock);
+	mutex_lock(&i2c->lock);
 	isr = xiic_getreg32(i2c, XIIC_IISR_OFFSET);
 	ier = xiic_getreg32(i2c, XIIC_IIER_OFFSET);
 	pend = isr & ier;
@@ -497,7 +497,7 @@ out:
 	dev_dbg(i2c->adap.dev.parent, "%s clr: 0x%x\n", __func__, clr);
 
 	xiic_setreg32(i2c, XIIC_IISR_OFFSET, clr);
-	spin_unlock(&i2c->lock);
+	mutex_unlock(&i2c->lock);
 	return IRQ_HANDLED;
 }
 
@@ -662,10 +662,10 @@ static void __xiic_start_xfer(struct xiic_i2c *i2c)
 
 static void xiic_start_xfer(struct xiic_i2c *i2c)
 {
-	spin_lock(&i2c->lock);
+	mutex_lock(&i2c->lock);
 	xiic_reinit(i2c);
 	__xiic_start_xfer(i2c);
-	spin_unlock(&i2c->lock);
+	mutex_unlock(&i2c->lock);
 }
 
 static int xiic_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
@@ -745,7 +745,7 @@ static int xiic_i2c_probe(struct platform_device *pdev)
 	i2c->adap.dev.parent = &pdev->dev;
 	i2c->adap.dev.of_node = pdev->dev.of_node;
 
-	spin_lock_init(&i2c->lock);
+	mutex_init(&i2c->lock);
 	init_waitqueue_head(&i2c->wait);
 
 	ret = devm_request_threaded_irq(&pdev->dev, irq, xiic_isr,