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usb: host: xhci-tegra: Implement basic ELPG support

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This implements basic engine-level powergate support which allows the
XUSB controller to be put into a low power mode on system sleep and get
it out of that low power mode again on resume.

Based on work by JC Kuo <jckuo@nvidia.com>.

Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://lore.kernel.org/r/20191206140653.2085561-11-thierry.reding@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Thierry Reding 2019-12-06 15:06:53 +01:00 committed by Greg Kroah-Hartman
parent 9ccae88e57
commit cad0a5c74e
1 changed files with 121 additions and 10 deletions
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131
drivers/usb/host/xhci-tegra.c
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@ -1447,6 +1447,45 @@ static int tegra_xusb_remove(struct platform_device *pdev)
}
#ifdef CONFIG_PM_SLEEP
static bool xhci_hub_ports_suspended(struct xhci_hub *hub)
{
struct device *dev = hub->hcd->self.controller;
bool status = true;
unsigned int i;
u32 value;
for (i = 0; i < hub->num_ports; i++) {
value = readl(hub->ports[i]->addr);
if ((value & PORT_PE) == 0)
continue;
if ((value & PORT_PLS_MASK) != XDEV_U3) {
dev_info(dev, "%u-%u isn't suspended: %#010x\n",
hub->hcd->self.busnum, i + 1, value);
status = false;
}
}
return status;
}
static int tegra_xusb_check_ports(struct tegra_xusb *tegra)
{
struct xhci_hcd *xhci = hcd_to_xhci(tegra->hcd);
unsigned long flags;
int err = 0;
spin_lock_irqsave(&xhci->lock, flags);
if (!xhci_hub_ports_suspended(&xhci->usb2_rhub) ||
!xhci_hub_ports_suspended(&xhci->usb3_rhub))
err = -EBUSY;
spin_unlock_irqrestore(&xhci->lock, flags);
return err;
}
static void tegra_xusb_save_context(struct tegra_xusb *tegra)
{
const struct tegra_xusb_context_soc *soc = tegra->soc->context;
@ -1481,31 +1520,103 @@ static void tegra_xusb_restore_context(struct tegra_xusb *tegra)
}
}
static int tegra_xusb_enter_elpg(struct tegra_xusb *tegra, bool wakeup)
{
struct xhci_hcd *xhci = hcd_to_xhci(tegra->hcd);
int err;
err = tegra_xusb_check_ports(tegra);
if (err < 0) {
dev_err(tegra->dev, "not all ports suspended: %d\n", err);
return err;
}
err = xhci_suspend(xhci, wakeup);
if (err < 0) {
dev_err(tegra->dev, "failed to suspend XHCI: %d\n", err);
return err;
}
tegra_xusb_save_context(tegra);
tegra_xusb_phy_disable(tegra);
tegra_xusb_clk_disable(tegra);
return 0;
}
static int tegra_xusb_exit_elpg(struct tegra_xusb *tegra, bool wakeup)
{
struct xhci_hcd *xhci = hcd_to_xhci(tegra->hcd);
int err;
err = tegra_xusb_clk_enable(tegra);
if (err < 0) {
dev_err(tegra->dev, "failed to enable clocks: %d\n", err);
return err;
}
err = tegra_xusb_phy_enable(tegra);
if (err < 0) {
dev_err(tegra->dev, "failed to enable PHYs: %d\n", err);
goto disable_clk;
}
tegra_xusb_config(tegra);
tegra_xusb_restore_context(tegra);
err = tegra_xusb_load_firmware(tegra);
if (err < 0) {
dev_err(tegra->dev, "failed to load firmware: %d\n", err);
goto disable_phy;
}
err = __tegra_xusb_enable_firmware_messages(tegra);
if (err < 0) {
dev_err(tegra->dev, "failed to enable messages: %d\n", err);
goto disable_phy;
}
err = xhci_resume(xhci, true);
if (err < 0) {
dev_err(tegra->dev, "failed to resume XHCI: %d\n", err);
goto disable_phy;
}
return 0;
disable_phy:
tegra_xusb_phy_disable(tegra);
disable_clk:
tegra_xusb_clk_disable(tegra);
return err;
}
static int tegra_xusb_suspend(struct device *dev)
{
struct tegra_xusb *tegra = dev_get_drvdata(dev);
struct xhci_hcd *xhci = hcd_to_xhci(tegra->hcd);
bool wakeup = device_may_wakeup(dev);
int err;
/* TODO: Powergate controller across suspend/resume. */
err = xhci_suspend(xhci, wakeup);
if (err < 0)
return err;
synchronize_irq(tegra->mbox_irq);
tegra_xusb_save_context(tegra);
mutex_lock(&tegra->lock);
err = tegra_xusb_enter_elpg(tegra, wakeup);
mutex_unlock(&tegra->lock);
return 0;
return err;
}
static int tegra_xusb_resume(struct device *dev)
{
struct tegra_xusb *tegra = dev_get_drvdata(dev);
struct xhci_hcd *xhci = hcd_to_xhci(tegra->hcd);
bool wakeup = device_may_wakeup(dev);
int err;
tegra_xusb_restore_context(tegra);
mutex_lock(&tegra->lock);
err = tegra_xusb_exit_elpg(tegra, wakeup);
mutex_unlock(&tegra->lock);
return xhci_resume(xhci, false);
return err;
}
#endif