smsc95xx: enable dynamic autosuspend

This patch enables USB dynamic autosuspend for LAN9500A.  This
saves very little power in itself, but it allows power saving
in upstream hubs/hosts.

The earlier devices in this family (LAN9500/9512/9514) do not
support this feature.

Signed-off-by: Steve Glendinning <steve.glendinning@shawell.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/usb/smsc95xx.c b/drivers/net/usb/smsc95xx.c
index 124e67f..6a74a68 100644 (file)
--- a/drivers/net/usb/smsc95xx.c
+++ b/drivers/net/usb/smsc95xx.c
@@ -55,6 +55,13 @@
 #define FEATURE_PHY_NLP_CROSSOVER      (0x02)
 #define FEATURE_AUTOSUSPEND            (0x04)
 
+#define SUSPEND_SUSPEND0               (0x01)
+#define SUSPEND_SUSPEND1               (0x02)
+#define SUSPEND_SUSPEND2               (0x04)
+#define SUSPEND_SUSPEND3               (0x08)
+#define SUSPEND_ALLMODES               (SUSPEND_SUSPEND0 | SUSPEND_SUSPEND1 | \
+                                        SUSPEND_SUSPEND2 | SUSPEND_SUSPEND3)
+
 struct smsc95xx_priv {
        u32 mac_cr;
        u32 hash_hi;
@@ -62,6 +69,7 @@ struct smsc95xx_priv {
        u32 wolopts;
        spinlock_t mac_cr_lock;
        u8 features;
+       u8 suspend_flags;
 };
 
 static bool turbo_mode = true;
@@ -1242,6 +1250,8 @@ static int smsc95xx_enter_suspend0(struct usbnet *dev)
        /* read back PM_CTRL */
        ret = smsc95xx_read_reg_nopm(dev, PM_CTRL, &val);
 
+       pdata->suspend_flags |= SUSPEND_SUSPEND0;
+
        return ret;
 }
 
@@ -1286,11 +1296,14 @@ static int smsc95xx_enter_suspend1(struct usbnet *dev)
 
        ret = smsc95xx_write_reg_nopm(dev, PM_CTRL, val);
 
+       pdata->suspend_flags |= SUSPEND_SUSPEND1;
+
        return ret;
 }
 
 static int smsc95xx_enter_suspend2(struct usbnet *dev)
 {
+       struct smsc95xx_priv *pdata = (struct smsc95xx_priv *)(dev->data[0]);
        u32 val;
        int ret;
 
@@ -1303,9 +1316,97 @@ static int smsc95xx_enter_suspend2(struct usbnet *dev)
 
        ret = smsc95xx_write_reg_nopm(dev, PM_CTRL, val);
 
+       pdata->suspend_flags |= SUSPEND_SUSPEND2;
+
        return ret;
 }
 
+static int smsc95xx_enter_suspend3(struct usbnet *dev)
+{
+       struct smsc95xx_priv *pdata = (struct smsc95xx_priv *)(dev->data[0]);
+       u32 val;
+       int ret;
+
+       ret = smsc95xx_read_reg_nopm(dev, RX_FIFO_INF, &val);
+       if (ret < 0)
+               return ret;
+
+       if (val & 0xFFFF) {
+               netdev_info(dev->net, "rx fifo not empty in autosuspend\n");
+               return -EBUSY;
+       }
+
+       ret = smsc95xx_read_reg_nopm(dev, PM_CTRL, &val);
+       if (ret < 0)
+               return ret;
+
+       val &= ~(PM_CTL_SUS_MODE_ | PM_CTL_WUPS_ | PM_CTL_PHY_RST_);
+       val |= PM_CTL_SUS_MODE_3 | PM_CTL_RES_CLR_WKP_STS;
+
+       ret = smsc95xx_write_reg_nopm(dev, PM_CTRL, val);
+       if (ret < 0)
+               return ret;
+
+       /* clear wol status */
+       val &= ~PM_CTL_WUPS_;
+       val |= PM_CTL_WUPS_WOL_;
+
+       ret = smsc95xx_write_reg_nopm(dev, PM_CTRL, val);
+       if (ret < 0)
+               return ret;
+
+       pdata->suspend_flags |= SUSPEND_SUSPEND3;
+
+       return 0;
+}
+
+static int smsc95xx_autosuspend(struct usbnet *dev, u32 link_up)
+{
+       struct smsc95xx_priv *pdata = (struct smsc95xx_priv *)(dev->data[0]);
+       int ret;
+
+       if (!netif_running(dev->net)) {
+               /* interface is ifconfig down so fully power down hw */
+               netdev_dbg(dev->net, "autosuspend entering SUSPEND2\n");
+               return smsc95xx_enter_suspend2(dev);
+       }
+
+       if (!link_up) {
+               /* link is down so enter EDPD mode, but only if device can
+                * reliably resume from it.  This check should be redundant
+                * as current FEATURE_AUTOSUSPEND parts also support
+                * FEATURE_PHY_NLP_CROSSOVER but it's included for clarity */
+               if (!(pdata->features & FEATURE_PHY_NLP_CROSSOVER)) {
+                       netdev_warn(dev->net, "EDPD not supported\n");
+                       return -EBUSY;
+               }
+
+               netdev_dbg(dev->net, "autosuspend entering SUSPEND1\n");
+
+               /* enable PHY wakeup events for if cable is attached */
+               ret = smsc95xx_enable_phy_wakeup_interrupts(dev,
+                       PHY_INT_MASK_ANEG_COMP_);
+               if (ret < 0) {
+                       netdev_warn(dev->net, "error enabling PHY wakeup ints\n");
+                       return ret;
+               }
+
+               netdev_info(dev->net, "entering SUSPEND1 mode\n");
+               return smsc95xx_enter_suspend1(dev);
+       }
+
+       /* enable PHY wakeup events so we remote wakeup if cable is pulled */
+       ret = smsc95xx_enable_phy_wakeup_interrupts(dev,
+               PHY_INT_MASK_LINK_DOWN_);
+       if (ret < 0) {
+               netdev_warn(dev->net, "error enabling PHY wakeup ints\n");
+               return ret;
+       }
+
+       netdev_dbg(dev->net, "autosuspend entering SUSPEND3\n");
+       return smsc95xx_enter_suspend3(dev);
+}
+
 static int smsc95xx_suspend(struct usb_interface *intf, pm_message_t message)
 {
        struct usbnet *dev = usb_get_intfdata(intf);
@@ -1313,15 +1414,35 @@ static int smsc95xx_suspend(struct usb_interface *intf, pm_message_t message)
        u32 val, link_up;
        int ret;
 
+       /* TODO: don't indicate this feature to usb framework if
+        * our current hardware doesn't have the capability
+        */
+       if ((message.event == PM_EVENT_AUTO_SUSPEND) &&
+           (!(pdata->features & FEATURE_AUTOSUSPEND))) {
+               netdev_warn(dev->net, "autosuspend not supported\n");
+               return -EBUSY;
+       }
+
        ret = usbnet_suspend(intf, message);
        if (ret < 0) {
                netdev_warn(dev->net, "usbnet_suspend error\n");
                return ret;
        }
 
+       if (pdata->suspend_flags) {
+               netdev_warn(dev->net, "error during last resume\n");
+               pdata->suspend_flags = 0;
+       }
+
        /* determine if link is up using only _nopm functions */
        link_up = smsc95xx_link_ok_nopm(dev);
 
+       if (message.event == PM_EVENT_AUTO_SUSPEND) {
+               ret = smsc95xx_autosuspend(dev, link_up);
+               goto done;
+       }
+
+       /* if we get this far we're not autosuspending */
        /* if no wol options set, or if link is down and we're not waking on
         * PHY activity, enter lowest power SUSPEND2 mode
         */
@@ -1552,12 +1673,18 @@ static int smsc95xx_resume(struct usb_interface *intf)
 {
        struct usbnet *dev = usb_get_intfdata(intf);
        struct smsc95xx_priv *pdata = (struct smsc95xx_priv *)(dev->data[0]);
+       u8 suspend_flags = pdata->suspend_flags;
        int ret;
        u32 val;
 
        BUG_ON(!dev);
 
-       if (pdata->wolopts) {
+       netdev_dbg(dev->net, "resume suspend_flags=0x%02x\n", suspend_flags);
+
+       /* do this first to ensure it's cleared even in error case */
+       pdata->suspend_flags = 0;
+
+       if (suspend_flags & SUSPEND_ALLMODES) {
                /* clear wake-up sources */
                ret = smsc95xx_read_reg_nopm(dev, WUCSR, &val);
                if (ret < 0)
@@ -1741,6 +1868,26 @@ static struct sk_buff *smsc95xx_tx_fixup(struct usbnet *dev,
        return skb;
 }
 
+static int smsc95xx_manage_power(struct usbnet *dev, int on)
+{
+       struct smsc95xx_priv *pdata = (struct smsc95xx_priv *)(dev->data[0]);
+
+       dev->intf->needs_remote_wakeup = on;
+
+       if (pdata->features & FEATURE_AUTOSUSPEND)
+               return 0;
+
+       /* this chip revision doesn't support autosuspend */
+       netdev_info(dev->net, "hardware doesn't support USB autosuspend\n");
+
+       if (on)
+               usb_autopm_get_interface_no_resume(dev->intf);
+       else
+               usb_autopm_put_interface(dev->intf);
+
+       return 0;
+}
+
 static const struct driver_info smsc95xx_info = {
        .description    = "smsc95xx USB 2.0 Ethernet",
        .bind           = smsc95xx_bind,
@@ -1750,6 +1897,7 @@ static const struct driver_info smsc95xx_info = {
        .rx_fixup       = smsc95xx_rx_fixup,
        .tx_fixup       = smsc95xx_tx_fixup,
        .status         = smsc95xx_status,
+       .manage_power   = smsc95xx_manage_power,
        .flags          = FLAG_ETHER | FLAG_SEND_ZLP | FLAG_LINK_INTR,
 };
 
@@ -1857,6 +2005,7 @@ static struct usb_driver smsc95xx_driver = {
        .reset_resume   = smsc95xx_resume,
        .disconnect     = usbnet_disconnect,
        .disable_hub_initiated_lpm = 1,
+       .supports_autosuspend = 1,
 };
 
 module_usb_driver(smsc95xx_driver);