[PATCH v7] can: xilinx: Convert to runtime_pm

From: Kedareswara rao Appana
Date: Fri Oct 23 2015 - 01:38:29 EST

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Instead of enabling/disabling clocks at several locations in the driver,
Use the runtime_pm framework. This consolidates the actions for runtime PM
In the appropriate callbacks and makes the driver more readable and mantainable.

Signed-off-by: Kedareswara rao Appana <appanad@xxxxxxxxxx>
---
Changes for v7:
- Removed the unnecessary clk_prepare/clk_unprepare calls
From the probe and remove as suggested by Soren.
Changes for v6:
- Updated the driver with review comments as suggested by Marc.
Changes for v5:
- Updated with the review comments.
Updated the remove fuction to use runtime_pm.
Chnages for v4:
- Updated with the review comments.
Changes for v3:
- Converted the driver to use runtime_pm.
Changes for v2:
- Removed the struct platform_device* from suspend/resume
as suggest by Lothar.

drivers/net/can/xilinx_can.c | 177 +++++++++++++++++++++++++------------------
1 file changed, 102 insertions(+), 75 deletions(-)

diff --git a/drivers/net/can/xilinx_can.c b/drivers/net/can/xilinx_can.c
index fc55e8e..fcb584f 100644
--- a/drivers/net/can/xilinx_can.c
+++ b/drivers/net/can/xilinx_can.c
@@ -32,6 +32,7 @@
#include <linux/can/dev.h>
#include <linux/can/error.h>
#include <linux/can/led.h>
+#include <linux/pm_runtime.h>

#define DRIVER_NAME "xilinx_can"

@@ -138,7 +139,7 @@ struct xcan_priv {
u32 (*read_reg)(const struct xcan_priv *priv, enum xcan_reg reg);
void (*write_reg)(const struct xcan_priv *priv, enum xcan_reg reg,
u32 val);
- struct net_device *dev;
+ struct device *dev;
void __iomem *reg_base;
unsigned long irq_flags;
struct clk *bus_clk;
@@ -843,6 +844,13 @@ static int xcan_open(struct net_device *ndev)
struct xcan_priv *priv = netdev_priv(ndev);
int ret;

+ ret = pm_runtime_get_sync(priv->dev);
+ if (ret < 0) {
+ netdev_err(ndev, "%s: pm_runtime_get failed(%d)\n",
+ __func__, ret);
+ return ret;
+ }
+
ret = request_irq(ndev->irq, xcan_interrupt, priv->irq_flags,
ndev->name, ndev);
if (ret < 0) {
@@ -850,29 +858,17 @@ static int xcan_open(struct net_device *ndev)
goto err;
}

- ret = clk_prepare_enable(priv->can_clk);
- if (ret) {
- netdev_err(ndev, "unable to enable device clock\n");
- goto err_irq;
- }
-
- ret = clk_prepare_enable(priv->bus_clk);
- if (ret) {
- netdev_err(ndev, "unable to enable bus clock\n");
- goto err_can_clk;
- }
-
/* Set chip into reset mode */
ret = set_reset_mode(ndev);
if (ret < 0) {
netdev_err(ndev, "mode resetting failed!\n");
- goto err_bus_clk;
+ goto err_irq;
}

/* Common open */
ret = open_candev(ndev);
if (ret)
- goto err_bus_clk;
+ goto err_irq;

ret = xcan_chip_start(ndev);
if (ret < 0) {
@@ -888,13 +884,11 @@ static int xcan_open(struct net_device *ndev)

err_candev:
close_candev(ndev);
-err_bus_clk:
- clk_disable_unprepare(priv->bus_clk);
-err_can_clk:
- clk_disable_unprepare(priv->can_clk);
err_irq:
free_irq(ndev->irq, ndev);
err:
+ pm_runtime_put(priv->dev);
+
return ret;
}

@@ -911,12 +905,11 @@ static int xcan_close(struct net_device *ndev)
netif_stop_queue(ndev);
napi_disable(&priv->napi);
xcan_chip_stop(ndev);
- clk_disable_unprepare(priv->bus_clk);
- clk_disable_unprepare(priv->can_clk);
free_irq(ndev->irq, ndev);
close_candev(ndev);

can_led_event(ndev, CAN_LED_EVENT_STOP);
+ pm_runtime_put(priv->dev);

return 0;
}
@@ -935,27 +928,20 @@ static int xcan_get_berr_counter(const struct net_device *ndev,
struct xcan_priv *priv = netdev_priv(ndev);
int ret;

- ret = clk_prepare_enable(priv->can_clk);
- if (ret)
- goto err;
-
- ret = clk_prepare_enable(priv->bus_clk);
- if (ret)
- goto err_clk;
+ ret = pm_runtime_get_sync(priv->dev);
+ if (ret < 0) {
+ netdev_err(ndev, "%s: pm_runtime_get failed(%d)\n",
+ __func__, ret);
+ return ret;
+ }

bec->txerr = priv->read_reg(priv, XCAN_ECR_OFFSET) & XCAN_ECR_TEC_MASK;
bec->rxerr = ((priv->read_reg(priv, XCAN_ECR_OFFSET) &
XCAN_ECR_REC_MASK) >> XCAN_ESR_REC_SHIFT);

- clk_disable_unprepare(priv->bus_clk);
- clk_disable_unprepare(priv->can_clk);
+ pm_runtime_put(priv->dev);

return 0;
-
-err_clk:
- clk_disable_unprepare(priv->can_clk);
-err:
- return ret;
}

@@ -968,15 +954,45 @@ static const struct net_device_ops xcan_netdev_ops = {

/**
* xcan_suspend - Suspend method for the driver
- * @dev: Address of the platform_device structure
+ * @dev: Address of the device structure
*
* Put the driver into low power mode.
- * Return: 0 always
+ * Return: 0 on success and failure value on error
*/
static int __maybe_unused xcan_suspend(struct device *dev)
{
- struct platform_device *pdev = dev_get_drvdata(dev);
- struct net_device *ndev = platform_get_drvdata(pdev);
+ if (!device_may_wakeup(dev))
+ return pm_runtime_force_suspend(dev);
+
+ return 0;
+}
+
+/**
+ * xcan_resume - Resume from suspend
+ * @dev: Address of the device structure
+ *
+ * Resume operation after suspend.
+ * Return: 0 on success and failure value on error
+ */
+static int __maybe_unused xcan_resume(struct device *dev)
+{
+ if (!device_may_wakeup(dev))
+ return pm_runtime_force_resume(dev);
+
+ return 0;
+
+}
+
+/**
+ * xcan_runtime_suspend - Runtime suspend method for the driver
+ * @dev: Address of the device structure
+ *
+ * Put the driver into low power mode.
+ * Return: 0 always
+ */
+static int __maybe_unused xcan_runtime_suspend(struct device *dev)
+{
+ struct net_device *ndev = dev_get_drvdata(dev);
struct xcan_priv *priv = netdev_priv(ndev);

if (netif_running(ndev)) {
@@ -987,43 +1003,55 @@ static int __maybe_unused xcan_suspend(struct device *dev)
priv->write_reg(priv, XCAN_MSR_OFFSET, XCAN_MSR_SLEEP_MASK);
priv->can.state = CAN_STATE_SLEEPING;

- clk_disable(priv->bus_clk);
- clk_disable(priv->can_clk);
+ clk_disable_unprepare(priv->bus_clk);
+ clk_disable_unprepare(priv->can_clk);

return 0;
}

/**
- * xcan_resume - Resume from suspend
- * @dev: Address of the platformdevice structure
+ * xcan_runtime_resume - Runtime resume from suspend
+ * @dev: Address of the device structure
*
* Resume operation after suspend.
* Return: 0 on success and failure value on error
*/
-static int __maybe_unused xcan_resume(struct device *dev)
+static int __maybe_unused xcan_runtime_resume(struct device *dev)
{
- struct platform_device *pdev = dev_get_drvdata(dev);
- struct net_device *ndev = platform_get_drvdata(pdev);
+ struct net_device *ndev = dev_get_drvdata(dev);
struct xcan_priv *priv = netdev_priv(ndev);
int ret;
+ u32 isr, status;

- ret = clk_enable(priv->bus_clk);
+ ret = clk_prepare_enable(priv->bus_clk);
if (ret) {
dev_err(dev, "Cannot enable clock.\n");
return ret;
}
- ret = clk_enable(priv->can_clk);
+ ret = clk_prepare_enable(priv->can_clk);
if (ret) {
dev_err(dev, "Cannot enable clock.\n");
clk_disable_unprepare(priv->bus_clk);
return ret;
}

- priv->write_reg(priv, XCAN_MSR_OFFSET, 0);
- priv->write_reg(priv, XCAN_SRR_OFFSET, XCAN_SRR_CEN_MASK);
- priv->can.state = CAN_STATE_ERROR_ACTIVE;
+ priv->write_reg(priv, XCAN_SRR_OFFSET, XCAN_SRR_RESET_MASK);
+ isr = priv->read_reg(priv, XCAN_ISR_OFFSET);
+ status = priv->read_reg(priv, XCAN_SR_OFFSET);

if (netif_running(ndev)) {
+ if (isr & XCAN_IXR_BSOFF_MASK) {
+ priv->can.state = CAN_STATE_BUS_OFF;
+ priv->write_reg(priv, XCAN_SRR_OFFSET,
+ XCAN_SRR_RESET_MASK);
+ } else if ((status & XCAN_SR_ESTAT_MASK) ==
+ XCAN_SR_ESTAT_MASK) {
+ priv->can.state = CAN_STATE_ERROR_PASSIVE;
+ } else if (status & XCAN_SR_ERRWRN_MASK) {
+ priv->can.state = CAN_STATE_ERROR_WARNING;
+ } else {
+ priv->can.state = CAN_STATE_ERROR_ACTIVE;
+ }
netif_device_attach(ndev);
netif_start_queue(ndev);
}
@@ -1031,7 +1059,10 @@ static int __maybe_unused xcan_resume(struct device *dev)
return 0;
}

-static SIMPLE_DEV_PM_OPS(xcan_dev_pm_ops, xcan_suspend, xcan_resume);
+static const struct dev_pm_ops xcan_dev_pm_ops = {
+ SET_SYSTEM_SLEEP_PM_OPS(xcan_suspend, xcan_resume)
+ SET_RUNTIME_PM_OPS(xcan_runtime_suspend, xcan_runtime_resume, NULL)
+};

/**
* xcan_probe - Platform registration call
@@ -1072,7 +1103,7 @@ static int xcan_probe(struct platform_device *pdev)
return -ENOMEM;

priv = netdev_priv(ndev);
- priv->dev = ndev;
+ priv->dev = &pdev->dev;
priv->can.bittiming_const = &xcan_bittiming_const;
priv->can.do_set_mode = xcan_do_set_mode;
priv->can.do_get_berr_counter = xcan_get_berr_counter;
@@ -1114,21 +1145,18 @@ static int xcan_probe(struct platform_device *pdev)
}
}

- ret = clk_prepare_enable(priv->can_clk);
- if (ret) {
- dev_err(&pdev->dev, "unable to enable device clock\n");
- goto err_free;
- }
-
- ret = clk_prepare_enable(priv->bus_clk);
- if (ret) {
- dev_err(&pdev->dev, "unable to enable bus clock\n");
- goto err_unprepare_disable_dev;
- }
-
priv->write_reg = xcan_write_reg_le;
priv->read_reg = xcan_read_reg_le;

+ pm_runtime_irq_safe(&pdev->dev);
+ pm_runtime_enable(&pdev->dev);
+ ret = pm_runtime_get_sync(&pdev->dev);
+ if (ret < 0) {
+ netdev_err(ndev, "%s: pm_runtime_get failed(%d)\n",
+ __func__, ret);
+ goto err_pmdisable;
+ }
+
if (priv->read_reg(priv, XCAN_SR_OFFSET) != XCAN_SR_CONFIG_MASK) {
priv->write_reg = xcan_write_reg_be;
priv->read_reg = xcan_read_reg_be;
@@ -1141,22 +1169,23 @@ static int xcan_probe(struct platform_device *pdev)
ret = register_candev(ndev);
if (ret) {
dev_err(&pdev->dev, "fail to register failed (err=%d)\n", ret);
- goto err_unprepare_disable_busclk;
+ goto err_disableclks;
}

devm_can_led_init(ndev);
- clk_disable_unprepare(priv->bus_clk);
- clk_disable_unprepare(priv->can_clk);
+
+ pm_runtime_put(&pdev->dev);
+
netdev_dbg(ndev, "reg_base=0x%p irq=%d clock=%d, tx fifo depth:%d\n",
priv->reg_base, ndev->irq, priv->can.clock.freq,
priv->tx_max);

return 0;

-err_unprepare_disable_busclk:
- clk_disable_unprepare(priv->bus_clk);
-err_unprepare_disable_dev:
- clk_disable_unprepare(priv->can_clk);
+err_disableclks:
+ pm_runtime_put(priv->dev);
+err_pmdisable:
+ pm_runtime_disable(&pdev->dev);
err_free:
free_candev(ndev);
err:
@@ -1175,10 +1204,8 @@ static int xcan_remove(struct platform_device *pdev)
struct net_device *ndev = platform_get_drvdata(pdev);
struct xcan_priv *priv = netdev_priv(ndev);

- if (set_reset_mode(ndev) < 0)
- netdev_err(ndev, "mode resetting failed!\n");
-
unregister_candev(ndev);
+ pm_runtime_disable(&pdev->dev);
netif_napi_del(&priv->napi);
free_candev(ndev);

--
2.1.2

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Next message: Bjorn Helgaas: "Re: [PATCH v7 03/60] sparc/PCI: Unify pci_register_region()"
Previous message: Ken Xue: "Re: [PATCH 1/2] i2c: designware: register clkdev during acpi device configuration"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]