libertas: Added callback functions to support SDIO suspend/resume.

In suspend() host sleep is activated using already configured
host sleep parameters through wol command, and in resume() host
sleep is cancelled. Earlier priv->fw_ready flag used to reset and
set in suspend and resume handler respectively. Since after suspend
only host goes into sleep state and firmware is always ready, those
changes in flag state are removed.

Signed-off-by: Amitkumar Karwar <akarwar@marvell.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/libertas/if_sdio.c

@@ -1182,11 +1182,69 @@ static void if_sdio_remove(struct sdio_func *func)
 	lbs_deb_leave(LBS_DEB_SDIO);
 }
 
+static int if_sdio_suspend(struct device *dev)
+{
+	struct sdio_func *func = dev_to_sdio_func(dev);
+	int ret;
+	struct if_sdio_card *card = sdio_get_drvdata(func);
+
+	mmc_pm_flag_t flags = sdio_get_host_pm_caps(func);
+
+	lbs_pr_info("%s: suspend: PM flags = 0x%x\n",
+						sdio_func_id(func), flags);
+
+	/* If we aren't being asked to wake on anything, we should bail out
+	 * and let the SD stack power down the card.
+	 */
+	if (card->priv->wol_criteria == EHS_REMOVE_WAKEUP) {
+		lbs_pr_info("Suspend without wake params -- "
+						"powering down card.");
+		return -ENOSYS;
+	}
+
+	if (!(flags & MMC_PM_KEEP_POWER)) {
+		lbs_pr_err("%s: cannot remain alive while host is suspended\n",
+			sdio_func_id(func));
+		return -ENOSYS;
+	}
+
+	ret = sdio_set_host_pm_flags(func, MMC_PM_KEEP_POWER);
+	if (ret)
+		return ret;
+
+	ret = lbs_suspend(card->priv);
+	if (ret)
+		return ret;
+
+	return sdio_set_host_pm_flags(func, MMC_PM_WAKE_SDIO_IRQ);
+}
+
+static int if_sdio_resume(struct device *dev)
+{
+	struct sdio_func *func = dev_to_sdio_func(dev);
+	struct if_sdio_card *card = sdio_get_drvdata(func);
+	int ret;
+
+	lbs_pr_info("%s: resume: we're back\n", sdio_func_id(func));
+
+	ret = lbs_resume(card->priv);
+
+	return ret;
+}
+
+static const struct dev_pm_ops if_sdio_pm_ops = {
+	.suspend	= if_sdio_suspend,
+	.resume		= if_sdio_resume,
+};
+
 static struct sdio_driver if_sdio_driver = {
 	.name		= "libertas_sdio",
 	.id_table	= if_sdio_ids,
 	.probe		= if_sdio_probe,
 	.remove		= if_sdio_remove,
+	.drv = {
+		.pm = &if_sdio_pm_ops,
+	},
 };
 
 /*******************************************************************/