Re: [PATCH 3/6] usb: cdns3-ti: add suspend/resume procedures for J7200

Roger Quadros
2023-11-15T11:37:58Z

On 13/11/2023 16:26, Théo Lebrun wrote:
> Hardware initialisation is only done at probe. The J7200 USB controller
> is reset at resume because of power-domains toggling off & on. We
> therefore (1) toggle PM runtime at suspend/resume & (2) reconfigure the
> hardware at resume.

at probe we are doing a pm_runtime_get() and never doing a put thus
preventing any runtime PM.

>
> Reuse the newly extracted cdns_ti_init_hw() function that contains the
> register write sequence.
>
> We guard this behavior based on compatible to avoid modifying the
> current behavior on other platforms. If the controller does not reset
> we do not want to touch PM runtime & do not want to redo reg writes.
>
> Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
> ---
> drivers/usb/cdns3/cdns3-ti.c | 48 +++++++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 47 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/usb/cdns3/cdns3-ti.c b/drivers/usb/cdns3/cdns3-ti.c
> index c331bcd2faeb..50b38c4b9c87 100644
> --- a/drivers/usb/cdns3/cdns3-ti.c
> +++ b/drivers/usb/cdns3/cdns3-ti.c
> @@ -197,6 +197,50 @@ static int cdns_ti_probe(struct platform_device *pdev)
> return error;
> }
>
> +#ifdef CONFIG_PM
> +
> +static int cdns_ti_suspend(struct device *dev)
> +{
> + struct cdns_ti *data = dev_get_drvdata(dev);
> +
> + if (!of_device_is_compatible(dev_of_node(dev), "ti,j7200-usb"))
> + return 0;
> +
> + pm_runtime_put_sync(data->dev);
> +
> + return 0;

You might want to check suspend/resume ops in cdns3-plat and
do something similar here.

> +}
> +
> +static int cdns_ti_resume(struct device *dev)
> +{
> + struct cdns_ti *data = dev_get_drvdata(dev);
> + int ret;
> +
> + if (!of_device_is_compatible(dev_of_node(dev), "ti,j7200-usb"))
> + return 0;
> +
> + ret = pm_runtime_get_sync(dev);
> + if (ret < 0) {
> + dev_err(dev, "pm_runtime_get_sync failed: %d\n", ret);
> + goto err;
> + }
> +
> + cdns_ti_init_hw(data);
> +
> + return 0;
> +
> +err:
> + pm_runtime_put_sync(data->dev);
> + pm_runtime_disable(data->dev);
> + return ret;
> +}
> +
> +static const struct dev_pm_ops cdns_ti_pm_ops = {
> + SET_SYSTEM_SLEEP_PM_OPS(cdns_ti_suspend, cdns_ti_resume)
> +};
> +
> +#endif /* CONFIG_PM */
> +
> static int cdns_ti_remove_core(struct device *dev, void *c)
> {
> struct platform_device *pdev = to_platform_device(dev);
> @@ -218,6 +262,7 @@ static void cdns_ti_remove(struct platform_device *pdev)
> }
>
> static const struct of_device_id cdns_ti_of_match[] = {
> + { .compatible = "ti,j7200-usb", },
> { .compatible = "ti,j721e-usb", },
> { .compatible = "ti,am64-usb", },
> {},
> @@ -228,8 +273,9 @@ static struct platform_driver cdns_ti_driver = {
> .probe = cdns_ti_probe,
> .remove_new = cdns_ti_remove,
> .driver = {
> - .name = "cdns3-ti",
> + .name = "cdns3-ti",
> .of_match_table = cdns_ti_of_match,
> + .pm = pm_ptr(&cdns_ti_pm_ops),
> },
> };
>
>

--
cheers,
-roger