On 10/23/2015 07:23 AM, 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: Kedareswara rao Appana <appa...@xilinx.com> > --- > 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);
Have you tested the patch with lockdep enabled? clk_prepare_enable() can sleep and pm_runtime_irq_safe() says that's it's ok to call the code from atomic context. Either remove the pm_runtime_irq_safe() or only call the clk_enable(), clk_disable in the RM runtime handlers. > + 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); > > Marc -- Pengutronix e.K. | Marc Kleine-Budde | Industrial Linux Solutions | Phone: +49-231-2826-924 | Vertretung West/Dortmund | Fax: +49-5121-206917-5555 | Amtsgericht Hildesheim, HRA 2686 | http://www.pengutronix.de |
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