On 12/23/2014 01:25 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.brinkm...@xilinx.com>
> Signed-off-by: Kedareswara rao Appana <appa...@xilinx.com>
> ---
> 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 | 123
> +++++++++++++++++++++++++-----------------
> 1 files changed, 74 insertions(+), 49 deletions(-)
>
> diff --git a/drivers/net/can/xilinx_can.c b/drivers/net/can/xilinx_can.c
> index 6c67643..c71f683 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: pm_runtime_get failed\r(%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 +927,20 @@ 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\r(%d)\n\r",
> + __func__, ret);
Please remove the \r from the error messages.
> + 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;
> }
>
>
> @@ -967,15 +953,45 @@ 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)) {
> @@ -993,16 +1009,15 @@ 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 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;
Some more context:
> ret = clk_enable(priv->bus_clk);
> if (ret) {
> dev_err(dev, "Cannot enable clock.\n");
> return ret;
> }
> ret = clk_enable(priv->can_clk);
> if (ret) {
> dev_err(dev, "Cannot enable clock.\n");
> clk_disable_unprepare(priv->bus_clk);
This disable_unprepare looks wrong, should be a disable only.
> return ret;
> }
>
> priv->write_reg(priv, XCAN_MSR_OFFSET, 0);
> priv->write_reg(priv, XCAN_SRR_OFFSET, XCAN_SRR_CEN_MASK);
>
> if (netif_running(ndev)) {
> priv->can.state = CAN_STATE_ERROR_ACTIVE;
What happens if the device was not in ACTIVE state prior to the
runtime_suspend?
> netif_device_attach(ndev);
> netif_start_queue(ndev);
> }
>
> return 0;
> }
>
> @@ -1020,9 +1035,9 @@ static int __maybe_unused xcan_resume(struct device
> *dev)
>
> 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;
>
> if (netif_running(ndev)) {
> + priv->can.state = CAN_STATE_ERROR_ACTIVE;
> netif_device_attach(ndev);
> netif_start_queue(ndev);
> }
> @@ -1030,7 +1045,10 @@ 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_PM_RUNTIME_PM_OPS(xcan_runtime_suspend, xcan_runtime_resume, NULL)
> +};
>
> /**
> * xcan_probe - Platform registration call
> @@ -1071,7 +1089,7 @@ 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;
> @@ -1137,15 +1155,22 @@ static int xcan_probe(struct platform_device *pdev)
>
> netif_napi_add(ndev, &priv->napi, xcan_rx_poll, rx_max);
>
> + pm_runtime_set_active(&pdev->dev);
> + pm_runtime_irq_safe(&pdev->dev);
> + pm_runtime_enable(&pdev->dev);
> + pm_runtime_get_sync(&pdev->dev);
Check error values?
> +
> ret = register_candev(ndev);
> if (ret) {
> dev_err(&pdev->dev, "fail to register failed (err=%d)\n", ret);
> + pm_runtime_put(priv->dev);
Please move the pm_runtime_put into the common error exit path.
> goto err_unprepare_disable_busclk;
> }
>
> 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);
>
I think you have to convert the _remove() function, too. Have a look at
the gpio-zynq.c driver:
> static int zynq_gpio_remove(struct platform_device *pdev)
> {
> struct zynq_gpio *gpio = platform_get_drvdata(pdev);
>
> pm_runtime_get_sync(&pdev->dev);
However I don't understand why the get_sync() is here. Maybe Sören can help?
> gpiochip_remove(&gpio->chip);
> clk_disable_unprepare(gpio->clk);
> device_set_wakeup_capable(&pdev->dev, 0);
> return 0;
> }
regards,
Marc
--
Pengutronix e.K. | Marc Kleine-Budde |
Industrial Linux Solutions | Phone: +49-231-2826-924 |
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