phy: usb: Leave some clocks running during suspend

[ Upstream commit 42fed57046fc74586d7058bd51a1c10ac9c690cb ]

The PHY client driver does a phy_exit() call on suspend or rmmod and
the PHY driver needs to know the difference because some clocks need
to be kept running for suspend but can be shutdown on unbind/rmmod
(or if there are no PHY clients at all).

The fix is to use a PM notifier so the driver can tell if a PHY
client is calling exit() because of a system suspend or a driver
unbind/rmmod.

Signed-off-by: Al Cooper <alcooperx@gmail.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/20211201180653.35097-2-alcooperx@gmail.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/phy/broadcom/phy-brcm-usb.c b/drivers/phy/broadcom/phy-brcm-usb.c
index 116fb23..0f1deb6 100644 (file)
--- a/drivers/phy/broadcom/phy-brcm-usb.c
+++ b/drivers/phy/broadcom/phy-brcm-usb.c
@@ -18,6 +18,7 @@
 #include <linux/soc/brcmstb/brcmstb.h>
 #include <dt-bindings/phy/phy.h>
 #include <linux/mfd/syscon.h>
+#include <linux/suspend.h>
 
 #include "phy-brcm-usb-init.h"
 
@@ -70,12 +71,35 @@ struct brcm_usb_phy_data {
        int                     init_count;
        int                     wake_irq;
        struct brcm_usb_phy     phys[BRCM_USB_PHY_ID_MAX];
+       struct notifier_block   pm_notifier;
+       bool                    pm_active;
 };
 
 static s8 *node_reg_names[BRCM_REGS_MAX] = {
        "crtl", "xhci_ec", "xhci_gbl", "usb_phy", "usb_mdio", "bdc_ec"
 };
 
+static int brcm_pm_notifier(struct notifier_block *notifier,
+                           unsigned long pm_event,
+                           void *unused)
+{
+       struct brcm_usb_phy_data *priv =
+               container_of(notifier, struct brcm_usb_phy_data, pm_notifier);
+
+       switch (pm_event) {
+       case PM_HIBERNATION_PREPARE:
+       case PM_SUSPEND_PREPARE:
+               priv->pm_active = true;
+               break;
+       case PM_POST_RESTORE:
+       case PM_POST_HIBERNATION:
+       case PM_POST_SUSPEND:
+               priv->pm_active = false;
+               break;
+       }
+       return NOTIFY_DONE;
+}
+
 static irqreturn_t brcm_usb_phy_wake_isr(int irq, void *dev_id)
 {
        struct phy *gphy = dev_id;
@@ -91,6 +115,9 @@ static int brcm_usb_phy_init(struct phy *gphy)
        struct brcm_usb_phy_data *priv =
                container_of(phy, struct brcm_usb_phy_data, phys[phy->id]);
 
+       if (priv->pm_active)
+               return 0;
+
        /*
         * Use a lock to make sure a second caller waits until
         * the base phy is inited before using it.
@@ -120,6 +147,9 @@ static int brcm_usb_phy_exit(struct phy *gphy)
        struct brcm_usb_phy_data *priv =
                container_of(phy, struct brcm_usb_phy_data, phys[phy->id]);
 
+       if (priv->pm_active)
+               return 0;
+
        dev_dbg(&gphy->dev, "EXIT\n");
        if (phy->id == BRCM_USB_PHY_2_0)
                brcm_usb_uninit_eohci(&priv->ini);
@@ -488,6 +518,9 @@ static int brcm_usb_phy_probe(struct platform_device *pdev)
        if (err)
                return err;
 
+       priv->pm_notifier.notifier_call = brcm_pm_notifier;
+       register_pm_notifier(&priv->pm_notifier);
+
        mutex_init(&priv->mutex);
 
        /* make sure invert settings are correct */
@@ -528,7 +561,10 @@ static int brcm_usb_phy_probe(struct platform_device *pdev)
 
 static int brcm_usb_phy_remove(struct platform_device *pdev)
 {
+       struct brcm_usb_phy_data *priv = dev_get_drvdata(&pdev->dev);
+
        sysfs_remove_group(&pdev->dev.kobj, &brcm_usb_phy_group);
+       unregister_pm_notifier(&priv->pm_notifier);
 
        return 0;
 }
@@ -539,6 +575,7 @@ static int brcm_usb_phy_suspend(struct device *dev)
        struct brcm_usb_phy_data *priv = dev_get_drvdata(dev);
 
        if (priv->init_count) {
+               dev_dbg(dev, "SUSPEND\n");
                priv->ini.wake_enabled = device_may_wakeup(dev);
                if (priv->phys[BRCM_USB_PHY_3_0].inited)
                        brcm_usb_uninit_xhci(&priv->ini);
@@ -578,6 +615,7 @@ static int brcm_usb_phy_resume(struct device *dev)
         * Uninitialize anything that wasn't previously initialized.
         */
        if (priv->init_count) {
+               dev_dbg(dev, "RESUME\n");
                if (priv->wake_irq >= 0)
                        disable_irq_wake(priv->wake_irq);
                brcm_usb_init_common(&priv->ini);