Patchwork [3/5] net: mvmdio: enhance driver to support SMI error/done interrupts

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Submitter Florian Fainelli
Date Jan. 29, 2013, 3:24 p.m.
Message ID <1359473048-26551-4-git-send-email-florian@openwrt.org>
Download mbox | patch
Permalink /patch/216590/
State Not Applicable
Headers show

Comments

Florian Fainelli - Jan. 29, 2013, 3:24 p.m.
This patch enhances the "mvmdio" to support a SMI error/done interrupt
line which can be used along with a wait queue instead of doing
busy-waiting on the registers. This is a feature which is available in
the mv643xx_eth SMI code and thus reduces again the gap between the two.

Signed-off-by: Florian Fainelli <florian@openwrt.org>
---
 .../devicetree/bindings/net/marvell-orion-mdio.txt |    3 +
 drivers/net/ethernet/marvell/mvmdio.c              |   83 +++++++++++++++++---
 2 files changed, 75 insertions(+), 11 deletions(-)
Thomas Petazzoni - Jan. 29, 2013, 3:39 p.m.
Dear Florian Fainelli,

On Tue, 29 Jan 2013 16:24:06 +0100, Florian Fainelli wrote:

>  #define MVMDIO_SMI_DATA_SHIFT              0
>  #define MVMDIO_SMI_PHY_ADDR_SHIFT          16
> @@ -36,12 +40,28 @@
>  #define MVMDIO_SMI_WRITE_OPERATION         0
>  #define MVMDIO_SMI_READ_VALID              BIT(27)
>  #define MVMDIO_SMI_BUSY                    BIT(28)
> +#define MVMDIO_ERR_INT_CAUSE		   0x007C
> +#define  MVMDIO_ERR_INT_SMI_DONE	   0x00000010
> +#define MVMDIO_ERR_INT_MASK		   0x0080
>  
>  struct orion_mdio_dev {
>  	struct mutex lock;
>  	void __iomem *regs;
> +	/*
> +	 * If we have access to the error interrupt pin (which is
> +	 * somewhat misnamed as it not only reflects internal errors
> +	 * but also reflects SMI completion), use that to wait for
> +	 * SMI access completion instead of polling the SMI busy bit.
> +	 */
> +	int err_interrupt;
> +	wait_queue_head_t smi_busy_wait;
>  };
>  
> +static int orion_mdio_smi_is_done(struct orion_mdio_dev *dev)
> +{
> +	return !(readl(dev->regs) & MVMDIO_SMI_BUSY);
> +}
> +
>  /* Wait for the SMI unit to be ready for another operation
>   */
>  static int orion_mdio_wait_ready(struct mii_bus *bus)
> @@ -50,19 +70,30 @@ static int orion_mdio_wait_ready(struct mii_bus *bus)
>  	int count;
>  	u32 val;
>  
> -	count = 0;
> -	while (1) {
> -		val = readl(dev->regs);
> -		if (!(val & MVMDIO_SMI_BUSY))
> -			break;
> -
> -		if (count > 100) {
> -			dev_err(bus->parent, "Timeout: SMI busy for too long\n");
> -			return -ETIMEDOUT;
> +	if (dev->err_interrupt == NO_IRQ) {
> +		count = 0;
> +		while (1) {
> +			val = readl(dev->regs);
> +			if (!(val & MVMDIO_SMI_BUSY))
> +				break;

What about using your new orion_mdio_smi_is_done() function here?

> +
> +			if (count > 100) {
> +				dev_err(bus->parent,
> +					"Timeout: SMI busy for too long\n");
> +				return -ETIMEDOUT;
> +			}
> +
> +			udelay(10);
> +			count++;
>  		}
> +	}
>  
> -		udelay(10);
> -		count++;
> +	if (!orion_mdio_smi_is_done(dev)) {

Maybe it should be in an else if block so that the waitqueue case is
only considered if there is an IRQ registered? Of course practically
speaking, it's OK because if there is no IRQ, we'll wait in the polling
loop above, and either exit from the function on timeout, or continue
on success. But it still would make the code a little bit clearer, I'd
say.

>  static int orion_mdio_probe(struct platform_device *pdev)
>  {
>  	struct device_node *np = pdev->dev.of_node;
> @@ -181,6 +227,19 @@ static int orion_mdio_probe(struct platform_device *pdev)
>  		return -ENODEV;
>  	}
>  
> +	dev->err_interrupt = NO_IRQ;

Not needed, you already do dev->err_interrupt = something() below.

> +	init_waitqueue_head(&dev->smi_busy_wait);
> +
> +	dev->err_interrupt = irq_of_parse_and_map(pdev->dev.of_node, 0);
> +	if (dev->err_interrupt != NO_IRQ) {
> +		ret = devm_request_irq(&pdev->dev, dev->err_interrupt,
> +					orion_mdio_err_irq,
> +					IRQF_SHARED, pdev->name, dev);
> +		if (!ret)
> +			writel(MVMDIO_ERR_INT_SMI_DONE,
> +					dev->regs + MVMDIO_ERR_INT_MASK);
> +	}
> +
>  	mutex_init(&dev->lock);
>  
>  	ret = of_mdiobus_register(bus, np);
> @@ -202,6 +261,8 @@ static int orion_mdio_remove(struct platform_device *pdev)
>  	struct mii_bus *bus = platform_get_drvdata(pdev);
>  	struct orion_mdio_dev *dev = bus->priv;
>  
> +	writel(0, dev->regs + MVMDIO_ERR_INT_MASK);
> +	free_irq(dev->err_interrupt, dev);

free_irq() not needed since the IRQ handler is registered with
devm_request_irq().

>  	mdiobus_unregister(bus);
>  	kfree(bus->irq);
>  	mdiobus_free(bus);

Thanks,

Thomas

Patch

diff --git a/Documentation/devicetree/bindings/net/marvell-orion-mdio.txt b/Documentation/devicetree/bindings/net/marvell-orion-mdio.txt
index 34e7aaf..052b5f2 100644
--- a/Documentation/devicetree/bindings/net/marvell-orion-mdio.txt
+++ b/Documentation/devicetree/bindings/net/marvell-orion-mdio.txt
@@ -9,6 +9,9 @@  Required properties:
 - compatible: "marvell,orion-mdio"
 - reg: address and length of the SMI register
 
+Optional properties:
+- interrupts: interrupt line number for the SMI error/done interrupt
+
 The child nodes of the MDIO driver are the individual PHY devices
 connected to this MDIO bus. They must have a "reg" property given the
 PHY address on the MDIO bus.
diff --git a/drivers/net/ethernet/marvell/mvmdio.c b/drivers/net/ethernet/marvell/mvmdio.c
index 5ecda58..cada794 100644
--- a/drivers/net/ethernet/marvell/mvmdio.c
+++ b/drivers/net/ethernet/marvell/mvmdio.c
@@ -24,10 +24,14 @@ 
 #include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/phy.h>
+#include <linux/interrupt.h>
 #include <linux/of_address.h>
 #include <linux/of_mdio.h>
+#include <linux/of_irq.h>
 #include <linux/platform_device.h>
 #include <linux/delay.h>
+#include <linux/sched.h>
+#include <linux/wait.h>
 
 #define MVMDIO_SMI_DATA_SHIFT              0
 #define MVMDIO_SMI_PHY_ADDR_SHIFT          16
@@ -36,12 +40,28 @@ 
 #define MVMDIO_SMI_WRITE_OPERATION         0
 #define MVMDIO_SMI_READ_VALID              BIT(27)
 #define MVMDIO_SMI_BUSY                    BIT(28)
+#define MVMDIO_ERR_INT_CAUSE		   0x007C
+#define  MVMDIO_ERR_INT_SMI_DONE	   0x00000010
+#define MVMDIO_ERR_INT_MASK		   0x0080
 
 struct orion_mdio_dev {
 	struct mutex lock;
 	void __iomem *regs;
+	/*
+	 * If we have access to the error interrupt pin (which is
+	 * somewhat misnamed as it not only reflects internal errors
+	 * but also reflects SMI completion), use that to wait for
+	 * SMI access completion instead of polling the SMI busy bit.
+	 */
+	int err_interrupt;
+	wait_queue_head_t smi_busy_wait;
 };
 
+static int orion_mdio_smi_is_done(struct orion_mdio_dev *dev)
+{
+	return !(readl(dev->regs) & MVMDIO_SMI_BUSY);
+}
+
 /* Wait for the SMI unit to be ready for another operation
  */
 static int orion_mdio_wait_ready(struct mii_bus *bus)
@@ -50,19 +70,30 @@  static int orion_mdio_wait_ready(struct mii_bus *bus)
 	int count;
 	u32 val;
 
-	count = 0;
-	while (1) {
-		val = readl(dev->regs);
-		if (!(val & MVMDIO_SMI_BUSY))
-			break;
-
-		if (count > 100) {
-			dev_err(bus->parent, "Timeout: SMI busy for too long\n");
-			return -ETIMEDOUT;
+	if (dev->err_interrupt == NO_IRQ) {
+		count = 0;
+		while (1) {
+			val = readl(dev->regs);
+			if (!(val & MVMDIO_SMI_BUSY))
+				break;
+
+			if (count > 100) {
+				dev_err(bus->parent,
+					"Timeout: SMI busy for too long\n");
+				return -ETIMEDOUT;
+			}
+
+			udelay(10);
+			count++;
 		}
+	}
 
-		udelay(10);
-		count++;
+	if (!orion_mdio_smi_is_done(dev)) {
+		wait_event_timeout(dev->smi_busy_wait,
+				orion_mdio_smi_is_done(dev),
+				msecs_to_jiffies(100));
+		if (!orion_mdio_smi_is_done(dev))
+			return -ETIMEDOUT;
 	}
 
 	return 0;
@@ -141,6 +172,21 @@  static int orion_mdio_reset(struct mii_bus *bus)
 	return 0;
 }
 
+static irqreturn_t orion_mdio_err_irq(int irq, void *dev_id)
+{
+	struct orion_mdio_dev *dev = dev_id;
+
+	if (readl(dev->regs + MVMDIO_ERR_INT_CAUSE) &
+			MVMDIO_ERR_INT_SMI_DONE) {
+		writel(~MVMDIO_ERR_INT_SMI_DONE,
+				dev->regs + MVMDIO_ERR_INT_CAUSE);
+		wake_up(&dev->smi_busy_wait);
+		return IRQ_HANDLED;
+	}
+
+	return IRQ_NONE;
+}
+
 static int orion_mdio_probe(struct platform_device *pdev)
 {
 	struct device_node *np = pdev->dev.of_node;
@@ -181,6 +227,19 @@  static int orion_mdio_probe(struct platform_device *pdev)
 		return -ENODEV;
 	}
 
+	dev->err_interrupt = NO_IRQ;
+	init_waitqueue_head(&dev->smi_busy_wait);
+
+	dev->err_interrupt = irq_of_parse_and_map(pdev->dev.of_node, 0);
+	if (dev->err_interrupt != NO_IRQ) {
+		ret = devm_request_irq(&pdev->dev, dev->err_interrupt,
+					orion_mdio_err_irq,
+					IRQF_SHARED, pdev->name, dev);
+		if (!ret)
+			writel(MVMDIO_ERR_INT_SMI_DONE,
+					dev->regs + MVMDIO_ERR_INT_MASK);
+	}
+
 	mutex_init(&dev->lock);
 
 	ret = of_mdiobus_register(bus, np);
@@ -202,6 +261,8 @@  static int orion_mdio_remove(struct platform_device *pdev)
 	struct mii_bus *bus = platform_get_drvdata(pdev);
 	struct orion_mdio_dev *dev = bus->priv;
 
+	writel(0, dev->regs + MVMDIO_ERR_INT_MASK);
+	free_irq(dev->err_interrupt, dev);
 	mdiobus_unregister(bus);
 	kfree(bus->irq);
 	mdiobus_free(bus);