Re: [PATCH v2 11/12] usb: host: xhci-tegra: unlink power domain devices

2020-09-07 Thread JC Kuo
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 
>> ---
>>  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
> 


Re: [PATCH v2 11/12] usb: host: xhci-tegra: unlink power domain devices

2020-08-31 Thread Thierry Reding
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 
> ---
>  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.

Thierry


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