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SubjectRe: [PATCH v7 5/8] can: m_can: Add PM Support
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Date
On 01/10/2018 11:55 AM, Faiz Abbas wrote:
> From: Franklin S Cooper Jr <fcooper@ti.com>
>
> Add support for CONFIG_PM which is the new way to handle managing clocks.
>
> Move the clock management to pm_runtime_resume() and pm_runtime_suspend()
> callbacks for the driver.
>
> CONFIG_PM is required by OMAP based devices to handle clock management.
> Therefore, this allows future Texas Instruments SoCs that have the MCAN IP
> to work with this driver.
>
> Reviewed-by: Suman Anna <s-anna@ti.com>
> Signed-off-by: Franklin S Cooper Jr <fcooper@ti.com>
> [nsekhar@ti.com: handle pm_runtime_get_sync() failure, fix some bugs]
> Signed-off-by: Sekhar Nori <nsekhar@ti.com>
> Signed-off-by: Faiz Abbas <faiz_abbas@ti.com>
> ---
> drivers/net/can/m_can/m_can.c | 95 ++++++++++++++++++++++++++++---------------
> 1 file changed, 62 insertions(+), 33 deletions(-)
>
> diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c
> index 07ebe7f..f5c5028 100644
> --- a/drivers/net/can/m_can/m_can.c
> +++ b/drivers/net/can/m_can/m_can.c
> @@ -23,6 +23,7 @@
> #include <linux/of.h>
> #include <linux/of_device.h>
> #include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>
> #include <linux/iopoll.h>
> #include <linux/can/dev.h>
>
> @@ -625,21 +626,16 @@ static int m_can_clk_start(struct m_can_priv *priv)
> {
> int err;
>
> - err = clk_prepare_enable(priv->hclk);
> - if (err)
> - return err;
> -
> - err = clk_prepare_enable(priv->cclk);
> + err = pm_runtime_get_sync(priv->device);
> if (err)
> - clk_disable_unprepare(priv->hclk);
> + pm_runtime_put_noidle(priv->device);
>
> return err;
> }
>
> static void m_can_clk_stop(struct m_can_priv *priv)
> {
> - clk_disable_unprepare(priv->cclk);
> - clk_disable_unprepare(priv->hclk);
> + pm_runtime_put_sync(priv->device);
> }
>
> static int m_can_get_berr_counter(const struct net_device *dev,
> @@ -1561,37 +1557,26 @@ static int m_can_plat_probe(struct platform_device *pdev)
> goto failed_ret;
> }
>
> - /* Enable clocks. Necessary to read Core Release in order to determine
> - * M_CAN version
> - */
> - ret = clk_prepare_enable(hclk);
> - if (ret)
> - goto disable_hclk_ret;
> -
> - ret = clk_prepare_enable(cclk);
> - if (ret)
> - goto disable_cclk_ret;
> -
> res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "m_can");
> addr = devm_ioremap_resource(&pdev->dev, res);
> irq = platform_get_irq_byname(pdev, "int0");
>
> if (IS_ERR(addr) || irq < 0) {
> ret = -EINVAL;
> - goto disable_cclk_ret;
> + goto failed_ret;
> }
>
> /* message ram could be shared */
> res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "message_ram");
> if (!res) {
> ret = -ENODEV;
> - goto disable_cclk_ret;
> + goto failed_ret;
> }
>
> mram_addr = devm_ioremap(&pdev->dev, res->start, resource_size(res));
> if (!mram_addr) {
> ret = -ENOMEM;
> - goto disable_cclk_ret;
> + goto failed_ret;
> }
>
> /* get message ram configuration */
> @@ -1600,7 +1585,7 @@ static int m_can_plat_probe(struct platform_device *pdev)
> sizeof(mram_config_vals) / 4);
> if (ret) {
> dev_err(&pdev->dev, "Could not get Message RAM configuration.");
> - goto disable_cclk_ret;
> + goto failed_ret;
> }
>
> /* Get TX FIFO size
> @@ -1612,13 +1597,9 @@ static int m_can_plat_probe(struct platform_device *pdev)
> dev = alloc_candev(sizeof(*priv), tx_fifo_size);
> if (!dev) {
> ret = -ENOMEM;
> - goto disable_cclk_ret;
> + goto failed_ret;
> }
>
> - ret = setup_m_can_dev(pdev, dev, addr);
> - if (ret)
> - goto disable_cclk_ret;
> -
> priv = netdev_priv(dev);
> dev->irq = irq;
> priv->device = &pdev->dev;
> @@ -1632,6 +1613,20 @@ static int m_can_plat_probe(struct platform_device *pdev)
> platform_set_drvdata(pdev, dev);
> SET_NETDEV_DEV(dev, &pdev->dev);
>
> + /* Enable clocks. Necessary to read Core Release in order to determine
> + * M_CAN version
> + */
> + pm_runtime_enable(&pdev->dev);
> + ret = pm_runtime_get_sync(&pdev->dev);

Why don't you make use of m_can_clk_start() here?

> + if (ret) {
> + pm_runtime_put_noidle(&pdev->dev);
> + goto pm_runtime_fail;
> + }
> +
> + ret = setup_m_can_dev(pdev, dev, addr);
> + if (ret)
> + goto pm_runtime_put;
> +
> ret = register_m_can_dev(dev);
> if (ret) {
> dev_err(&pdev->dev, "registering %s failed (err=%d)\n",
> @@ -1650,14 +1645,15 @@ static int m_can_plat_probe(struct platform_device *pdev)
> * Stop clocks. They will be reactivated once the M_CAN device is opened
> */
>
> - goto disable_cclk_ret;
> + goto pm_runtime_put;
>
> failed_free_dev:
> free_m_can_dev(dev);
> -disable_cclk_ret:
> - clk_disable_unprepare(cclk);
> -disable_hclk_ret:
> - clk_disable_unprepare(hclk);
> +pm_runtime_put:
> + pm_runtime_put_sync(&pdev->dev);
> +pm_runtime_fail:
> + if (ret)
> + pm_runtime_disable(&pdev->dev);
> failed_ret:
> return ret;
> }
> @@ -1715,6 +1711,9 @@ static int m_can_plat_remove(struct platform_device *pdev)
> struct net_device *dev = platform_get_drvdata(pdev);
>
> unregister_m_can_dev(dev);
> +
> + pm_runtime_disable(&pdev->dev);
> +
> platform_set_drvdata(pdev, NULL);
>
> free_m_can_dev(dev);
> @@ -1722,7 +1721,37 @@ static int m_can_plat_remove(struct platform_device *pdev)
> return 0;
> }
>
> +int m_can_runtime_suspend(struct device *dev)
> +{
> + struct net_device *ndev = dev_get_drvdata(dev);
> + struct m_can_priv *priv = netdev_priv(ndev);
> +
> + clk_disable_unprepare(priv->cclk);
> + clk_disable_unprepare(priv->hclk);
> +
> + return 0;
> +}
> +
> +int m_can_runtime_resume(struct device *dev)
> +{
> + struct net_device *ndev = dev_get_drvdata(dev);
> + struct m_can_priv *priv = netdev_priv(ndev);
> + int err;
> +
> + err = clk_prepare_enable(priv->hclk);
> + if (err)
> + return err;
> +
> + err = clk_prepare_enable(priv->cclk);
> + if (err)
> + clk_disable_unprepare(priv->hclk);
> +
> + return err;
> +}
> +
> static const struct dev_pm_ops m_can_pmops = {
> + SET_RUNTIME_PM_OPS(m_can_runtime_suspend,
> + m_can_runtime_resume, NULL)
> SET_SYSTEM_SLEEP_PM_OPS(m_can_suspend, m_can_resume)
> };
>
>

Marc

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