On Mon, Aug 31, 2020 at 12:40:43PM +0800, JC Kuo wrote:
> This commit implements the complete programming sequence for ELPG
> entry and exit.
>
> 1. At ELPG entry, invokes tegra_xusb_padctl_enable_phy_sleepwalk()
> and tegra_xusb_padctl_enable_phy_wake() to configure XUSB PADCTL
> sleepwalk and wake detection circuits to maintain USB lines level
> and respond to wake events (wake-on-connect, wake-on-disconnect,
> device-initiated-wake).
>
> 2. At ELPG exit, invokes tegra_xusb_padctl_disable_phy_sleepwalk()
> and tegra_xusb_padctl_disable_phy_wake() to disarm sleepwalk and
> wake detection circuits.
>
> At runtime suspend, XUSB host controller can enter ELPG to reduce
> power consumption. When XUSB PADCTL wake detection circuit detects
> a wake event, an interrupt will be raised. xhci-tegra driver then
> will invoke pm_runtime_resume() for xhci-tegra.
>
> Runtime resume could also be triggered by protocol drivers, this is
> the host-initiated-wake event. At runtime resume, xhci-tegra driver
> brings XUSB host controller out of ELPG to handle the wake events.
>
> The same ELPG enter/exit procedure will be performed for system
> suspend/resume path so USB devices can remain connected across SC7.
>
> Signed-off-by: JC Kuo <jckuo@xxxxxxxxxx>
> ---
> drivers/usb/host/xhci-tegra.c | 391 +++++++++++++++++++++++++++++++---
> 1 file changed, 361 insertions(+), 30 deletions(-)
>
> diff --git a/drivers/usb/host/xhci-tegra.c b/drivers/usb/host/xhci-tegra.c
> index ce6526c2caf6..9530cfc83f45 100644
> --- a/drivers/usb/host/xhci-tegra.c
> +++ b/drivers/usb/host/xhci-tegra.c
> @@ -15,9 +15,11 @@
> #include <linux/kernel.h>
> #include <linux/module.h>
> #include <linux/of_device.h>
> +#include <linux/of_irq.h>
> #include <linux/phy/phy.h>
> #include <linux/phy/tegra/xusb.h>
> #include <linux/platform_device.h>
> +#include <linux/usb/ch9.h>
> #include <linux/pm.h>
> #include <linux/pm_domain.h>
> #include <linux/pm_runtime.h>
> @@ -224,6 +226,7 @@ struct tegra_xusb {
>
> int xhci_irq;
> int mbox_irq;
> + int padctl_irq;
>
> void __iomem *ipfs_base;
> void __iomem *fpci_base;
> @@ -268,10 +271,13 @@ struct tegra_xusb {
> dma_addr_t phys;
> } fw;
>
> + bool suspended;
> struct tegra_xusb_context context;
> };
>
> static struct hc_driver __read_mostly tegra_xhci_hc_driver;
> +static int tegra_xusb_exit_elpg(struct tegra_xusb *tegra, bool runtime);
> +static int tegra_xusb_enter_elpg(struct tegra_xusb *tegra, bool runtime);
>
> static inline u32 fpci_readl(struct tegra_xusb *tegra, unsigned int offset)
> {
> @@ -657,6 +663,9 @@ static irqreturn_t tegra_xusb_mbox_thread(int irq, void *data)
>
> mutex_lock(&tegra->lock);
>
> + if (pm_runtime_suspended(tegra->dev) || tegra->suspended)
> + goto out;
> +
> value = fpci_readl(tegra, tegra->soc->mbox.data_out);
> tegra_xusb_mbox_unpack(&msg, value);
>
> @@ -670,6 +679,7 @@ static irqreturn_t tegra_xusb_mbox_thread(int irq, void *data)
>
> tegra_xusb_mbox_handle(tegra, &msg);
>
> +out:
> mutex_unlock(&tegra->lock);
> return IRQ_HANDLED;
> }
> @@ -812,12 +822,27 @@ static void tegra_xusb_phy_disable(struct tegra_xusb *tegra)
>
> static int tegra_xusb_runtime_suspend(struct device *dev)
> {
> - return 0;
> + struct tegra_xusb *tegra = dev_get_drvdata(dev);
> + int ret;
> +
> + synchronize_irq(tegra->mbox_irq);
> + mutex_lock(&tegra->lock);
> + ret = tegra_xusb_enter_elpg(tegra, true);
> + mutex_unlock(&tegra->lock);
> +
> + return ret;
> }
>
> static int tegra_xusb_runtime_resume(struct device *dev)
> {
> - return 0;
> + struct tegra_xusb *tegra = dev_get_drvdata(dev);
> + int err;
> +
> + mutex_lock(&tegra->lock);
> + err = tegra_xusb_exit_elpg(tegra, true);
> + mutex_unlock(&tegra->lock);
> +
> + return err;
> }
>
> #ifdef CONFIG_PM_SLEEP
> @@ -1121,6 +1146,22 @@ static int __tegra_xusb_enable_firmware_messages(struct tegra_xusb *tegra)
> return err;
> }
>
> +static irqreturn_t tegra_xusb_padctl_irq(int irq, void *data)
> +{
> + struct tegra_xusb *tegra = data;
> +
> + mutex_lock(&tegra->lock);
> + if (tegra->suspended) {
> + mutex_unlock(&tegra->lock);
> + return IRQ_HANDLED;
> + }
> + mutex_unlock(&tegra->lock);
Blank lines before and after a block can help make this less cluttered.
> +
> + pm_runtime_resume(tegra->dev);
> +
> + return IRQ_HANDLED;
> +}
> +
> static int tegra_xusb_enable_firmware_messages(struct tegra_xusb *tegra)
> {
> int err;
> @@ -1244,6 +1285,51 @@ static void tegra_xhci_id_work(struct work_struct *work)
> }
> }
>
> +static bool is_usb2_otg_phy(struct tegra_xusb *tegra, int index)
unsigned int index?
> +{
> + return (tegra->usbphy[index] != NULL);
> +}
> +
> +static bool is_usb3_otg_phy(struct tegra_xusb *tegra, int index)
Here too.
> +{
> + struct tegra_xusb_padctl *padctl = tegra->padctl;
> + int i, port;
These can also be unsigned.
> +
> + for (i = 0; i < tegra->num_usb_phys; i++) {
> + if (is_usb2_otg_phy(tegra, i)) {
> + port = tegra_xusb_padctl_get_usb3_companion(padctl,i);
Space after ",".
> + if (index == port)
> + return true;
> + }
> + }
> +
> + return false;
> +}
> +
> +static bool is_host_mode_phy(struct tegra_xusb *tegra, int phy_type, int index)
> +{
> + if (strcmp(tegra->soc->phy_types[phy_type].name, "hsic") == 0)
> + return true;
> +
> + if (strcmp(tegra->soc->phy_types[phy_type].name, "usb2") == 0) {
> + if (is_usb2_otg_phy(tegra, index)) {
> + return ((index == tegra->otg_usb2_port) &&
> + tegra->host_mode);
> + } else
> + return true;
> + }
> +
> + if (strcmp(tegra->soc->phy_types[phy_type].name, "usb3") == 0) {
> + if (is_usb3_otg_phy(tegra, index)) {
> + return ((index == tegra->otg_usb3_port) &&
> + tegra->host_mode);
> + } else
> + return true;
> + }
> +
> + return false;
> +}
> +
> static int tegra_xusb_get_usb2_port(struct tegra_xusb *tegra,
> struct usb_phy *usbphy)
> {
> @@ -1336,6 +1422,7 @@ static void tegra_xusb_deinit_usb_phy(struct tegra_xusb *tegra)
> static int tegra_xusb_probe(struct platform_device *pdev)
> {
> struct tegra_xusb *tegra;
> + struct device_node *np;
> struct resource *regs;
> struct xhci_hcd *xhci;
> unsigned int i, j, k;
> @@ -1383,6 +1470,14 @@ static int tegra_xusb_probe(struct platform_device *pdev)
> if (IS_ERR(tegra->padctl))
> return PTR_ERR(tegra->padctl);
>
> + np = of_parse_phandle(pdev->dev.of_node, "nvidia,xusb-padctl", 0);
> + if (!np)
> + return -ENODEV;
> +
> + tegra->padctl_irq = of_irq_get(np, 0);
> + if (tegra->padctl_irq < 0)
> + return tegra->padctl_irq;
> +
> tegra->host_clk = devm_clk_get(&pdev->dev, "xusb_host");
> if (IS_ERR(tegra->host_clk)) {
> err = PTR_ERR(tegra->host_clk);
> @@ -1527,6 +1622,7 @@ static int tegra_xusb_probe(struct platform_device *pdev)
> goto put_powerdomains;
> }
>
> + tegra->hcd->skip_phy_initialization = 1;
> tegra->hcd->regs = tegra->regs;
> tegra->hcd->rsrc_start = regs->start;
> tegra->hcd->rsrc_len = resource_size(regs);
> @@ -1609,12 +1705,6 @@ static int tegra_xusb_probe(struct platform_device *pdev)
> goto put_usb3;
> }
>
> - err = tegra_xusb_enable_firmware_messages(tegra);
> - if (err < 0) {
> - dev_err(&pdev->dev, "failed to enable messages: %d\n", err);
> - goto remove_usb3;
> - }
> -
> err = devm_request_threaded_irq(&pdev->dev, tegra->mbox_irq,
> tegra_xusb_mbox_irq,
> tegra_xusb_mbox_thread, 0,
> @@ -1624,12 +1714,40 @@ static int tegra_xusb_probe(struct platform_device *pdev)
> goto remove_usb3;
> }
>
> + err = devm_request_threaded_irq(&pdev->dev, tegra->padctl_irq,
> + NULL,
> + tegra_xusb_padctl_irq,
> + IRQF_ONESHOT |
> + IRQF_TRIGGER_HIGH,
> + dev_name(&pdev->dev), tegra);
The alignment here is off. Also, try to make good use of those 100
columns.
> + if (err < 0) {
> + dev_err(&pdev->dev, "failed to request padctl IRQ: %d\n", err);
> + goto remove_usb3;
> + }
> +
> + err = tegra_xusb_enable_firmware_messages(tegra);
> + if (err < 0) {
> + dev_err(&pdev->dev, "failed to enable messages: %d\n", err);
> + goto remove_usb3;
> + }
> +
> err = tegra_xusb_init_usb_phy(tegra);
> if (err < 0) {
> dev_err(&pdev->dev, "failed to init USB PHY: %d\n", err);
> goto remove_usb3;
> }
>
> + /* Enable wake for both USB 2.0 and USB 3.0 roothubs */
> + device_init_wakeup(&tegra->hcd->self.root_hub->dev, true);
> + device_init_wakeup(&xhci->shared_hcd->self.root_hub->dev, true);
> + device_init_wakeup(tegra->dev, true);
> +
> + pm_runtime_use_autosuspend(tegra->dev);
> + pm_runtime_set_autosuspend_delay(tegra->dev, 2000);
> + pm_runtime_mark_last_busy(tegra->dev);
> + pm_runtime_set_active(tegra->dev);
> + pm_runtime_enable(tegra->dev);
> +
> return 0;
>
> remove_usb3:
> @@ -1665,6 +1783,7 @@ static int tegra_xusb_remove(struct platform_device *pdev)
>
> tegra_xusb_deinit_usb_phy(tegra);
>
> + pm_runtime_get_sync(&pdev->dev);
> usb_remove_hcd(xhci->shared_hcd);
> usb_put_hcd(xhci->shared_hcd);
> xhci->shared_hcd = NULL;
> @@ -1674,8 +1793,8 @@ static int tegra_xusb_remove(struct platform_device *pdev)
> dma_free_coherent(&pdev->dev, tegra->fw.size, tegra->fw.virt,
> tegra->fw.phys);
>
> - pm_runtime_put_sync(&pdev->dev);
> pm_runtime_disable(&pdev->dev);
> + pm_runtime_put(&pdev->dev);
>
> tegra_xusb_powergate_partitions(tegra);
>
> @@ -1717,9 +1836,17 @@ static bool xhci_hub_ports_suspended(struct xhci_hub *hub)
> static int tegra_xusb_check_ports(struct tegra_xusb *tegra)
> {
> struct xhci_hcd *xhci = hcd_to_xhci(tegra->hcd);
> + struct xhci_hub *rhub = xhci_get_rhub(xhci->main_hcd);
> + struct xhci_bus_state *bus_state = &rhub->bus_state;
> unsigned long flags;
> int err = 0;
>
> + if (bus_state->bus_suspended) {
> + /* xusb_hub_suspend() has just directed one or more USB2 port(s)
> + * to U3 state, it takes 3ms to enter U3. */
> + usleep_range(3000, 4000);
> + }
> +
> spin_lock_irqsave(&xhci->lock, flags);
>
> if (!xhci_hub_ports_suspended(&xhci->usb2_rhub) ||
> @@ -1765,45 +1892,184 @@ static void tegra_xusb_restore_context(struct tegra_xusb *tegra)
> }
> }
>
> -static int tegra_xusb_enter_elpg(struct tegra_xusb *tegra, bool wakeup)
> +static enum usb_device_speed
> +tegra_xhci_portsc_to_speed(struct tegra_xusb *tegra, u32 portsc)
> +{
> + if (DEV_LOWSPEED(portsc))
> + return USB_SPEED_LOW;
> + else if (DEV_HIGHSPEED(portsc))
> + return USB_SPEED_HIGH;
> + else if (DEV_FULLSPEED(portsc))
> + return USB_SPEED_FULL;
> + else if (DEV_SUPERSPEED_ANY(portsc))
> + return USB_SPEED_SUPER;
> + else
> + return USB_SPEED_UNKNOWN;
> +}
As in a prior patch you can make this simpler by dropping the elses.
> +
> +static void tegra_xhci_enable_phy_sleepwalk_wake(struct tegra_xusb *tegra)
> +{
> + struct tegra_xusb_padctl *padctl = tegra->padctl;
> + struct xhci_hcd *xhci = hcd_to_xhci(tegra->hcd);
> + enum usb_device_speed speed;
> + struct phy *phy;
> + int index, offset;
> + int i, j, k;
It looks like these can all be unsigned int.
> + struct xhci_hub *rhub;
> + u32 portsc;
> +
> + for (i = 0, k = 0; i < tegra->soc->num_types; i++) {
> + if (strcmp(tegra->soc->phy_types[i].name, "usb3") == 0)
> + rhub = &xhci->usb3_rhub;
> + else
> + rhub = &xhci->usb2_rhub;
> +
> + if (strcmp(tegra->soc->phy_types[i].name, "hsic") == 0)
> + offset = tegra->soc->ports.usb2.count;
> + else
> + offset = 0;
> +
> + for (j = 0; j < tegra->soc->phy_types[i].num; j++) {
> + phy = tegra->phys[k++];
> +
> + if (!phy)
> + continue;
> +
> + index = j + offset;
> +
> + if (index >= rhub->num_ports)
> + continue;
> +
> + if (!is_host_mode_phy(tegra, i, j))
> + continue;
> +
> + portsc = readl(rhub->ports[index]->addr);
> + speed = tegra_xhci_portsc_to_speed(tegra, portsc);
> + tegra_xusb_padctl_enable_phy_sleepwalk(padctl, phy,
> + speed);
> + tegra_xusb_padctl_enable_phy_wake(padctl, phy);
> + }
> + }
> +}
> +
> +static void tegra_xhci_disable_phy_wake(struct tegra_xusb *tegra)
> +{
> + struct tegra_xusb_padctl *padctl = tegra->padctl;
> + int i;
Same here.
> +
> + for (i = 0; i < tegra->num_phys; i++) {
> + if (!tegra->phys[i])
> + continue;
> +
> + tegra_xusb_padctl_disable_phy_wake(padctl, tegra->phys[i]);
> + }
> +}
> +
> +static void tegra_xhci_disable_phy_sleepwalk(struct tegra_xusb *tegra)
> +{
> + struct tegra_xusb_padctl *padctl = tegra->padctl;
> + int i;
And here.
> +
> + for (i = 0; i < tegra->num_phys; i++) {
> + if (!tegra->phys[i])
> + continue;
> +
> + tegra_xusb_padctl_disable_phy_sleepwalk(padctl, tegra->phys[i]);
> + }
> +}
> +
> +static int tegra_xusb_enter_elpg(struct tegra_xusb *tegra, bool runtime)
> {
> struct xhci_hcd *xhci = hcd_to_xhci(tegra->hcd);
> + struct device *dev = tegra->dev;
> + bool wakeup = runtime ? true : device_may_wakeup(dev);
> + unsigned int i;
> int err;
> + u32 usbcmd;
> +
> + dev_dbg(dev, "entering ELPG\n");
> +
> + usbcmd = readl(&xhci->op_regs->command);
> + usbcmd &= ~CMD_EIE;
> + writel(usbcmd, &xhci->op_regs->command);
>
> err = tegra_xusb_check_ports(tegra);
> if (err < 0) {
> dev_err(tegra->dev, "not all ports suspended: %d\n", err);
> - return err;
> + goto out;
> }
>
> err = xhci_suspend(xhci, wakeup);
> if (err < 0) {
> dev_err(tegra->dev, "failed to suspend XHCI: %d\n", err);
> - return err;
> + goto out;
> }
>
> tegra_xusb_save_context(tegra);
> - tegra_xusb_phy_disable(tegra);
> +
> + if (wakeup)
> + tegra_xhci_enable_phy_sleepwalk_wake(tegra);
> +
> + tegra_xusb_powergate_partitions(tegra);
> +
> + for (i = 0; i < tegra->num_phys; i++) {
> + if (!tegra->phys[i])
> + continue;
> +
> + phy_power_off(tegra->phys[i]);
> + if (!wakeup)
> + phy_exit(tegra->phys[i]);
> + }
> tegra_xusb_clk_disable(tegra);
Use blank lines to separate blocks of code.
>
> - return 0;
> +out:
> + if (!err)
> + dev_dbg(tegra->dev, "entering ELPG done\n");
> + else {
> + usbcmd = readl(&xhci->op_regs->command);
> + usbcmd |= CMD_EIE;
> + writel(usbcmd, &xhci->op_regs->command);
> +
> + dev_dbg(tegra->dev, "entering ELPG failed\n");
> + pm_runtime_mark_last_busy(tegra->dev);
> + }
> +
> + return err;
> }
>
> -static int tegra_xusb_exit_elpg(struct tegra_xusb *tegra, bool wakeup)
> +static int tegra_xusb_exit_elpg(struct tegra_xusb *tegra, bool runtime)
> {
> struct xhci_hcd *xhci = hcd_to_xhci(tegra->hcd);
> + struct device *dev = tegra->dev;
> + bool wakeup = runtime ? true : device_may_wakeup(dev);
> + unsigned int i;
> + u32 usbcmd;
> int err;
>
> + dev_dbg(dev, "exiting ELPG\n");
> + pm_runtime_mark_last_busy(tegra->dev);
> +
> err = tegra_xusb_clk_enable(tegra);
> if (err < 0) {
> dev_err(tegra->dev, "failed to enable clocks: %d\n", err);
> - return err;
> + goto out;
> }
>
> - err = tegra_xusb_phy_enable(tegra);
> - if (err < 0) {
> - dev_err(tegra->dev, "failed to enable PHYs: %d\n", err);
> - goto disable_clk;
> + err = tegra_xusb_unpowergate_partitions(tegra);
> + if (err)
> + goto disable_clks;
> +
> + if (wakeup)
> + tegra_xhci_disable_phy_wake(tegra);
> +
> + for (i = 0; i < tegra->num_phys; i++) {
> + if (!tegra->phys[i])
> + continue;
> +
> + if (!wakeup)
> + phy_init(tegra->phys[i]);
> +
> + phy_power_on(tegra->phys[i]);
> }
>
> tegra_xusb_config(tegra);
> @@ -1821,31 +2087,78 @@ static int tegra_xusb_exit_elpg(struct tegra_xusb *tegra, bool wakeup)
> goto disable_phy;
> }
>
> - err = xhci_resume(xhci, true);
> + if (wakeup)
> + tegra_xhci_disable_phy_sleepwalk(tegra);
> +
> + err = xhci_resume(xhci, 0);
> if (err < 0) {
> dev_err(tegra->dev, "failed to resume XHCI: %d\n", err);
> goto disable_phy;
> }
>
> - return 0;
> + usbcmd = readl(&xhci->op_regs->command);
> + usbcmd |= CMD_EIE;
> + writel(usbcmd, &xhci->op_regs->command);
> +
> + goto out;
>
> disable_phy:
> - tegra_xusb_phy_disable(tegra);
> -disable_clk:
> + for (i = 0; i < tegra->num_phys; i++) {
> + if (!tegra->phys[i])
> + continue;
> +
> + phy_power_off(tegra->phys[i]);
> + if (!wakeup)
> + phy_exit(tegra->phys[i]);
> + }
> + tegra_xusb_powergate_partitions(tegra);
> +disable_clks:
> tegra_xusb_clk_disable(tegra);
> +out:
> + if (!err)
> + dev_dbg(dev, "exiting ELPG done\n");
> + else
> + dev_dbg(dev, "exiting ELPG failed\n");
> +
> return err;
> }
>
> static int tegra_xusb_suspend(struct device *dev)
> {
> struct tegra_xusb *tegra = dev_get_drvdata(dev);
> - bool wakeup = device_may_wakeup(dev);
> int err;
>
> synchronize_irq(tegra->mbox_irq);
> -
I think that blank line actually helped with readability.
Thierry
> mutex_lock(&tegra->lock);
> - err = tegra_xusb_enter_elpg(tegra, wakeup);
> +
> + if (pm_runtime_suspended(dev)) {
> + err = tegra_xusb_exit_elpg(tegra, true);
> + if (err < 0)
> + goto out;
> + }
> +
> + err = tegra_xusb_enter_elpg(tegra, false);
> + if (err < 0) {
> + if (pm_runtime_suspended(dev)) {
> + pm_runtime_disable(dev);
> + pm_runtime_set_active(dev);
> + pm_runtime_enable(dev);
> + }
> +
> + goto out;
> + }
> +
> +out:
> + if (!err) {
> + tegra->suspended = true;
> + pm_runtime_disable(dev);
> +
> + if (device_may_wakeup(dev)) {
> + if (enable_irq_wake(tegra->padctl_irq))
> + dev_err(dev, "failed to enable padctl wakes\n");
> + }
> + }
> +
> mutex_unlock(&tegra->lock);
>
> return err;
> @@ -1854,14 +2167,32 @@ static int tegra_xusb_suspend(struct device *dev)
> static int tegra_xusb_resume(struct device *dev)
> {
> struct tegra_xusb *tegra = dev_get_drvdata(dev);
> - bool wakeup = device_may_wakeup(dev);
> int err;
>
> mutex_lock(&tegra->lock);
> - err = tegra_xusb_exit_elpg(tegra, wakeup);
> +
> + if (!tegra->suspended) {
> + mutex_unlock(&tegra->lock);
> + return 0;
> + }
> +
> + err = tegra_xusb_exit_elpg(tegra, false);
> + if (err < 0) {
> + mutex_unlock(&tegra->lock);
> + return err;
> + }
> +
> + if (device_may_wakeup(dev)) {
> + if (disable_irq_wake(tegra->padctl_irq))
> + dev_err(dev, "failed to disable padctl wakes\n");
> + }
> + tegra->suspended = false;
> mutex_unlock(&tegra->lock);
>
> - return err;
> + pm_runtime_set_active(dev);
> + pm_runtime_enable(dev);
> +
> + return 0;
> }
> #endif
>
> --
> 2.25.1
>
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