[PATCH 3/4 v2] net: mvmdio: enhance driver to support SMI error/done interrupts

Florian Fainelli
2013-03-14T18:20:36Z

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>
---
Chances since v1:
- always use orion_smi_is_done() helper
- make interrupt/non-interrupt code path entirely independant

.../devicetree/bindings/net/marvell-orion-mdio.txt | 3 +
drivers/net/ethernet/marvell/mvmdio.c | 83 +++++++++++++++++---
2 files changed, 74 insertions(+), 12 deletions(-)

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 595deea..7ac83de 100644
--- a/drivers/net/ethernet/marvell/mvmdio.c
+++ b/drivers/net/ethernet/marvell/mvmdio.c
@@ -24,9 +24,12 @@
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/phy.h>
+#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/delay.h>
#include <linux/io.h>
+#include <linux/sched.h>
+#include <linux/wait.h>

#define MVMDIO_SMI_DATA_SHIFT 0
#define MVMDIO_SMI_PHY_ADDR_SHIFT 16
@@ -35,33 +38,58 @@
#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)
{
struct orion_mdio_dev *dev = bus->priv;
int count;
- u32 val;

- count = 0;
- while (1) {
- val = readl(dev->regs);
- if (!(val & MVMDIO_SMI_BUSY))
- break;
+ if (dev->err_interrupt == NO_IRQ) {
+ count = 0;
+ while (1) {
+ if (orion_mdio_smi_is_done(dev))
+ break;

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

- udelay(10);
- count++;
+ udelay(10);
+ count++;
+ }
+ } else {
+ 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;
@@ -140,6 +168,21 @@ 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 resource *r;
@@ -185,6 +228,19 @@ static int orion_mdio_probe(struct platform_device *pdev)
return -ENODEV;
}

+ init_waitqueue_head(&dev->smi_busy_wait);
+
+ dev->err_interrupt = platform_get_irq(pdev, 0);
+ if (dev->err_interrupt != -ENXIO) {
+ 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);
+ } else
+ dev->err_interrupt = NO_IRQ;
+
mutex_init(&dev->lock);

ret = mdiobus_register(bus);
@@ -203,6 +259,9 @@ static int orion_mdio_probe(struct platform_device *pdev)
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);
mdiobus_unregister(bus);
kfree(bus->irq);
mdiobus_free(bus);
--
1.7.10.4