On 8/31/20 8:42 PM, Thierry Reding wrote:
> On Mon, Aug 31, 2020 at 12:40:42PM +0800, JC Kuo wrote:
>> This commit unlinks xhci-tegra platform device with ss/host power
>> domain devices. Reasons for this change is - at elpg entry, phy
>> sleepwalk and wake configuration need to be done before powering
>> down ss/host partitions, and phy need be powered off after powering
>> down ss/host partitions. Sequence looks like roughly below:
>>
>> tegra_xusb_enter_elpg() -> xhci_suspend()
>> -> enable phy sleepwalk and wake if needed
>> -> power down ss/host partitions
>> -> power down phy
>>
>> If ss/host power domains are linked to xhci-tegra platform device, we
>> are not able to perform the sequence like above.
>>
>> This commit introduces:
>> 1. tegra_xusb_unpowergate_partitions() to power up ss and host
>> partitions together. If ss/host power domain devices are
>> available, it invokes pm_runtime_get_sync() to request power
>> driver to power up partitions; If power domain devices are not
>> available, tegra_powergate_sequence_power_up() will be used to
>> power up partitions.
>>
>> 2. tegra_xusb_powergate_partitions() to power down ss and host
>> partitions together. If ss/host power domain devices are
>> available, it invokes pm_runtime_put_sync() to request power
>> driver to power down partitions; If power domain devices are not
>> available, tegra_powergate_power_off() will be used to power down
>> partitions.
>>
>> Signed-off-by: JC Kuo <jckuo@xxxxxxxxxx>
>> ---
>> drivers/usb/host/xhci-tegra.c | 202 +++++++++++++++++++---------------
>> 1 file changed, 111 insertions(+), 91 deletions(-)
>>
>> diff --git a/drivers/usb/host/xhci-tegra.c b/drivers/usb/host/xhci-tegra.c
>> index 934be1686352..ce6526c2caf6 100644
>> --- a/drivers/usb/host/xhci-tegra.c
>> +++ b/drivers/usb/host/xhci-tegra.c
>> @@ -249,8 +249,6 @@ struct tegra_xusb {
>>
>> struct device *genpd_dev_host;
>> struct device *genpd_dev_ss;
>> - struct device_link *genpd_dl_host;
>> - struct device_link *genpd_dl_ss;
>>
>> struct phy **phys;
>> unsigned int num_phys;
>> @@ -814,36 +812,12 @@ static void tegra_xusb_phy_disable(struct tegra_xusb *tegra)
>>
>> static int tegra_xusb_runtime_suspend(struct device *dev)
>> {
>> - struct tegra_xusb *tegra = dev_get_drvdata(dev);
>> -
>> - regulator_bulk_disable(tegra->soc->num_supplies, tegra->supplies);
>> - tegra_xusb_clk_disable(tegra);
>> -
>> return 0;
>> }
>>
>> static int tegra_xusb_runtime_resume(struct device *dev)
>> {
>> - struct tegra_xusb *tegra = dev_get_drvdata(dev);
>> - int err;
>> -
>> - err = tegra_xusb_clk_enable(tegra);
>> - if (err) {
>> - dev_err(dev, "failed to enable clocks: %d\n", err);
>> - return err;
>> - }
>> -
>> - err = regulator_bulk_enable(tegra->soc->num_supplies, tegra->supplies);
>> - if (err) {
>> - dev_err(dev, "failed to enable regulators: %d\n", err);
>> - goto disable_clk;
>> - }
>> -
>> return 0;
>> -
>> -disable_clk:
>> - tegra_xusb_clk_disable(tegra);
>> - return err;
>> }
>>
>> #ifdef CONFIG_PM_SLEEP
>> @@ -1019,10 +993,6 @@ static int tegra_xusb_load_firmware(struct tegra_xusb *tegra)
>> static void tegra_xusb_powerdomain_remove(struct device *dev,
>> struct tegra_xusb *tegra)
>> {
>> - if (tegra->genpd_dl_ss)
>> - device_link_del(tegra->genpd_dl_ss);
>> - if (tegra->genpd_dl_host)
>> - device_link_del(tegra->genpd_dl_host);
>> if (!IS_ERR_OR_NULL(tegra->genpd_dev_ss))
>> dev_pm_domain_detach(tegra->genpd_dev_ss, true);
>> if (!IS_ERR_OR_NULL(tegra->genpd_dev_host))
>> @@ -1048,20 +1018,88 @@ static int tegra_xusb_powerdomain_init(struct device *dev,
>> return err;
>> }
>>
>> - tegra->genpd_dl_host = device_link_add(dev, tegra->genpd_dev_host,
>> - DL_FLAG_PM_RUNTIME |
>> - DL_FLAG_STATELESS);
>> - if (!tegra->genpd_dl_host) {
>> - dev_err(dev, "adding host device link failed!\n");
>> - return -ENODEV;
>> + return 0;
>> +}
>> +
>> +static int tegra_xusb_unpowergate_partitions(struct tegra_xusb *tegra)
>> +{
>> + struct device *dev = tegra->dev;
>> + bool use_genpd;
>> + int rc;
>> +
>> + use_genpd = of_property_read_bool(dev->of_node, "power-domains");
>
> I don't think that's technically correct. Just because a "power-domains"
> property exists in DT doesn't mean any power domains are necessarily
> attached to the device. I think you'll need to check for something like
>
> if (dev->pm_domain)
>
> here.
>
Thanks Thierry. I will do so in the next revision.
> Thierry
>
