net: smsc911x: add power management functions

This adds a power management implementation for smsc911x.c which assumes
the chips remains powered during suspend. The device is put in its D1
power saving mode.

Signed-off-by: Daniel Mack <daniel@caiaq.de>
Acked-by: Steve Glendinning <steve.glendinning@smsc.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 46 insertions, 0 deletions

diff --git a/drivers/net/smsc911x.c b/drivers/net/smsc911x.c
index 5113b26fc2d9..9a8528c5bb5e 100644
--- a/drivers/net/smsc911x.c
+++ b/drivers/net/smsc911x.c
@@ -2109,12 +2109,58 @@ out_0:
         return retval;
 }
 
+#ifdef CONFIG_PM
+/* This implementation assumes the devices remains powered on its VDDVARIO
+ * pins during suspend. */
+
+static int smsc911x_suspend(struct platform_device *pdev, pm_message_t state)
+{
+        struct net_device *dev = platform_get_drvdata(pdev);
+        struct smsc911x_data *pdata = netdev_priv(dev);
+
+        /* enable wake on LAN, energy detection and the external PME
+         * signal. */
+        smsc911x_reg_write(pdata, PMT_CTRL,
+                PMT_CTRL_PM_MODE_D1_ | PMT_CTRL_WOL_EN_ |
+                PMT_CTRL_ED_EN_ | PMT_CTRL_PME_EN_);
+
+        return 0;
+}
+
+static int smsc911x_resume(struct platform_device *pdev)
+{
+        struct net_device *dev = platform_get_drvdata(pdev);
+        struct smsc911x_data *pdata = netdev_priv(dev);
+        unsigned int to = 100;
+
+        /* Note 3.11 from the datasheet:
+         *      "When the LAN9220 is in a power saving state, a write of any
+         *       data to the BYTE_TEST register will wake-up the device."
+         */
+        smsc911x_reg_write(pdata, BYTE_TEST, 0);
+
+        /* poll the READY bit in PMT_CTRL. Any other access to the device is
+         * forbidden while this bit isn't set. Try for 100ms and return -EIO
+         * if it failed. */
+        while (!(smsc911x_reg_read(pdata, PMT_CTRL) & PMT_CTRL_READY_) && --to)
+                udelay(1000);
+
+        return (to == 0) ? -EIO : 0;
+}
+
+#else
+#define smsc911x_suspend        NULL
+#define smsc911x_resume         NULL
+#endif
+
 static struct platform_driver smsc911x_driver = {
         .probe = smsc911x_drv_probe,
         .remove = smsc911x_drv_remove,
         .driver = {
                 .name = SMSC_CHIPNAME,
         },
+        .suspend = smsc911x_suspend,
+        .resume = smsc911x_resume,
 };
 
 /* Entry point for loading the module */