1 files changed, 19 insertions, 20 deletions

diff --git a/drivers/i2c/busses/i2c-altera.c b/drivers/i2c/busses/i2c-altera.c
index 20ef63820c77..7d62cbda6e06 100644
--- a/drivers/i2c/busses/i2c-altera.c
+++ b/drivers/i2c/busses/i2c-altera.c
@@ -69,7 +69,7 @@
  * @fifo_size: size of the FIFO passed in.
  * @isr_mask: cached copy of local ISR enables.
  * @isr_status: cached copy of local ISR status.
- * @lock: spinlock for IRQ synchronization.
+ * @isr_mutex: mutex for IRQ thread.
  */
 struct altr_i2c_dev {
 	void __iomem *base;
@@ -85,17 +85,14 @@ struct altr_i2c_dev {
 	u32 fifo_size;
 	u32 isr_mask;
 	u32 isr_status;
-	spinlock_t lock;	/* IRQ synchronization */
+	struct mutex isr_mutex;
 };
 
 static void
 altr_i2c_int_enable(struct altr_i2c_dev *idev, u32 mask, bool enable)
 {
-	unsigned long flags;
 	u32 int_en;
 
-	spin_lock_irqsave(&idev->lock, flags);
-
 	int_en = readl(idev->base + ALTR_I2C_ISER);
 	if (enable)
 		idev->isr_mask = int_en | mask;
@@ -103,8 +100,6 @@ altr_i2c_int_enable(struct altr_i2c_dev *idev, u32 mask, bool enable)
 		idev->isr_mask = int_en & ~mask;
 
 	writel(idev->isr_mask, idev->base + ALTR_I2C_ISER);
-
-	spin_unlock_irqrestore(&idev->lock, flags);
 }
 
 static void altr_i2c_int_clear(struct altr_i2c_dev *idev, u32 mask)
@@ -245,10 +240,11 @@ static irqreturn_t altr_i2c_isr(int irq, void *_dev)
 	struct altr_i2c_dev *idev = _dev;
 	u32 status = idev->isr_status;
 
+	mutex_lock(&idev->isr_mutex);
 	if (!idev->msg) {
 		dev_warn(idev->dev, "unexpected interrupt\n");
 		altr_i2c_int_clear(idev, ALTR_I2C_ALL_IRQ);
-		return IRQ_HANDLED;
+		goto out;
 	}
 	read = (idev->msg->flags & I2C_M_RD) != 0;
 
@@ -301,6 +297,8 @@ static irqreturn_t altr_i2c_isr(int irq, void *_dev)
 		complete(&idev->msg_complete);
 		dev_dbg(idev->dev, "Message Complete\n");
 	}
+out:
+	mutex_unlock(&idev->isr_mutex);
 
 	return IRQ_HANDLED;
 }
@@ -312,6 +310,7 @@ static int altr_i2c_xfer_msg(struct altr_i2c_dev *idev, struct i2c_msg *msg)
 	u32 value;
 	u8 addr = i2c_8bit_addr_from_msg(msg);
 
+	mutex_lock(&idev->isr_mutex);
 	idev->msg = msg;
 	idev->msg_len = msg->len;
 	idev->buf = msg->buf;
@@ -336,9 +335,11 @@ static int altr_i2c_xfer_msg(struct altr_i2c_dev *idev, struct i2c_msg *msg)
 		altr_i2c_int_enable(idev, imask, true);
 		altr_i2c_fill_tx_fifo(idev);
 	}
+	mutex_unlock(&idev->isr_mutex);
 
 	time_left = wait_for_completion_timeout(&idev->msg_complete,
 						ALTR_I2C_XFER_TIMEOUT);
+	mutex_lock(&idev->isr_mutex);
 	altr_i2c_int_enable(idev, imask, false);
 
 	value = readl(idev->base + ALTR_I2C_STATUS) & ALTR_I2C_STAT_CORE;
@@ -351,6 +352,7 @@ static int altr_i2c_xfer_msg(struct altr_i2c_dev *idev, struct i2c_msg *msg)
 	}
 
 	altr_i2c_core_disable(idev);
+	mutex_unlock(&idev->isr_mutex);
 
 	return idev->msg_err;
 }
@@ -382,24 +384,19 @@ static const struct i2c_algorithm altr_i2c_algo = {
 static int altr_i2c_probe(struct platform_device *pdev)
 {
 	struct altr_i2c_dev *idev = NULL;
-	struct resource *res;
 	int irq, ret;
-	u32 val;
 
 	idev = devm_kzalloc(&pdev->dev, sizeof(*idev), GFP_KERNEL);
 	if (!idev)
 		return -ENOMEM;
 
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	idev->base = devm_ioremap_resource(&pdev->dev, res);
+	idev->base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(idev->base))
 		return PTR_ERR(idev->base);
 
 	irq = platform_get_irq(pdev, 0);
-	if (irq < 0) {
-		dev_err(&pdev->dev, "missing interrupt resource\n");
+	if (irq < 0)
 		return irq;
-	}
 
 	idev->i2c_clk = devm_clk_get(&pdev->dev, NULL);
 	if (IS_ERR(idev->i2c_clk)) {
@@ -409,19 +406,19 @@ static int altr_i2c_probe(struct platform_device *pdev)
 
 	idev->dev = &pdev->dev;
 	init_completion(&idev->msg_complete);
-	spin_lock_init(&idev->lock);
+	mutex_init(&idev->isr_mutex);
 
-	val = device_property_read_u32(idev->dev, "fifo-size",
+	ret = device_property_read_u32(idev->dev, "fifo-size",
 				       &idev->fifo_size);
-	if (val) {
+	if (ret) {
 		dev_err(&pdev->dev, "FIFO size set to default of %d\n",
 			ALTR_I2C_DFLT_FIFO_SZ);
 		idev->fifo_size = ALTR_I2C_DFLT_FIFO_SZ;
 	}
 
-	val = device_property_read_u32(idev->dev, "clock-frequency",
+	ret = device_property_read_u32(idev->dev, "clock-frequency",
 				       &idev->bus_clk_rate);
-	if (val) {
+	if (ret) {
 		dev_err(&pdev->dev, "Default to 100kHz\n");
 		idev->bus_clk_rate = I2C_MAX_STANDARD_MODE_FREQ;	/* default clock rate */
 	}
@@ -446,7 +443,9 @@ static int altr_i2c_probe(struct platform_device *pdev)
 		return ret;
 	}
 
+	mutex_lock(&idev->isr_mutex);
 	altr_i2c_init(idev);
+	mutex_unlock(&idev->isr_mutex);
 
 	i2c_set_adapdata(&idev->adapter, idev);
 	strlcpy(idev->adapter.name, pdev->name, sizeof(idev->adapter.name));