[PATCH v3] can: Convert to runtime_pm
Appana Durga Kedareswara Rao
appana.durga.rao at xilinx.com
Thu Nov 27 17:47:42 PST 2014
Hi Michal,
-----Original Message-----
From: Michal Simek [mailto:michal.simek at xilinx.com]
Sent: Thursday, November 27, 2014 8:17 PM
To: Appana Durga Kedareswara Rao; wg at grandegger.com; mkl at pengutronix.de; Michal Simek; Soren Brinkmann; grant.likely at linaro.org; robh+dt at kernel.org
Cc: linux-can at vger.kernel.org; netdev at vger.kernel.org; linux-arm-kernel at lists.infradead.org; linux-kernel at vger.kernel.org; devicetree at vger.kernel.org; Appana Durga Kedareswara Rao
Subject: Re: [PATCH v3] can: Convert to runtime_pm
On 11/27/2014 02:08 PM, Kedareswara rao Appana wrote:
> 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: Soren Brinkmann <soren.brinkmann at xilinx.com>
> Signed-off-by: Kedareswara rao Appana <appanad at xilinx.com>
> ---
> 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 | 119
> +++++++++++++++++++++++++----------------
> 1 files changed, 72 insertions(+), 47 deletions(-)
>
> diff --git a/drivers/net/can/xilinx_can.c
> b/drivers/net/can/xilinx_can.c index 8a998e3..1be28ed 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;
> @@ -842,6 +843,13 @@ 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: runtime CAN resume failed(%d)\n\r",
> + __func__, ret);
> + return ret;
> + }
> +
> ret = request_irq(ndev->irq, xcan_interrupt, priv->irq_flags,
> ndev->name, ndev);
> if (ret < 0) {
> @@ -849,29 +857,17 @@ 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) {
> @@ -887,13 +883,11 @@ 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;
> }
>
> @@ -910,12 +904,11 @@ 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;
> }
> @@ -934,27 +927,21 @@ 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 = pm_runtime_get_sync(priv->dev);
> + if (ret < 0) {
> + netdev_err(ndev, "%s: runtime resume failed(%d)\n\r",
> + __func__, ret);
> + return ret;
> + }
>
> - ret = clk_prepare_enable(priv->bus_clk);
> - if (ret)
> - goto err_clk;
>
> 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;
> }
>
>
> @@ -967,15 +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 net_device structure
This is just the device structure.
K will modify in the next version of the patch .
> *
> * 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 net_device structure
ditto
K will modify in the next version of the patch .
> + *
> + * 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 net_device structure
ditto.
K will modify in the next version of the patch .
> + *
> + * 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)) {
> @@ -993,16 +1010,15 @@ static int __maybe_unused xcan_suspend(struct
> device *dev) }
>
> /**
> - * xcan_resume - Resume from suspend
> - * @dev: Address of the platformdevice structure
> + * xcan_runtime_resume - Runtime resume from suspend
> + * @dev: Address of the net_device structure
ditto.
K will modify in the next version of the patch .
Regards,
Kedar.
Thanks,
Michal
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