libertas: implement suspend and resume core methods

We (ab)use priv->fw_ready to stop the worker thread from sending more
commands or data after the response to the HOST_SLEEP_ACTIVATE command
comes in. And we set it from the callback function _directly_ to ensure
that the worker thread sees it immediately; if we did it in
lbs_suspend() after waking up, that might be too late.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/libertas/cmd.h

@@ -35,5 +35,7 @@ int lbs_mesh_config(struct lbs_private *priv, int enable);
 
 int lbs_host_sleep_cfg(struct lbs_private *priv, uint32_t criteria,
 		       uint8_t gpio, uint8_t gap);
+int lbs_suspend(struct lbs_private *priv);
+int lbs_resume(struct lbs_private *priv);
 
 #endif /* _LBS_CMD_H */

drivers/net/wireless/libertas/main.c

@@ -820,6 +820,53 @@ static int lbs_thread(void *data)
 	return 0;
 }
 
+static int lbs_suspend_callback(struct lbs_private *priv, unsigned long dummy,
+				struct cmd_header *cmd)
+{
+	lbs_deb_fw("HOST_SLEEP_ACTIVATE succeeded\n");
+
+	netif_device_detach(priv->dev);
+	if (priv->mesh_dev)
+		netif_device_detach(priv->mesh_dev);
+
+	priv->fw_ready = 0;
+	return 0;
+}
+
+
+int lbs_suspend(struct lbs_private *priv)
+{
+	struct cmd_header cmd;
+	int ret;
+
+	memset(&cmd, 0, sizeof(cmd));
+
+	ret = __lbs_cmd(priv, CMD_802_11_HOST_SLEEP_ACTIVATE, &cmd,
+			sizeof(cmd), lbs_suspend_callback, 0);
+	if (ret)
+		lbs_pr_info("HOST_SLEEP_ACTIVATE failed: %d\n", ret);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(lbs_suspend);
+
+int lbs_resume(struct lbs_private *priv)
+{
+	priv->fw_ready = 1;
+
+	/* Firmware doesn't seem to give us RX packets any more
+	   until we send it some command. Might as well update */
+	lbs_prepare_and_send_command(priv, CMD_802_11_RSSI, 0,
+				     0, 0, NULL);
+
+	netif_device_attach(priv->dev);
+	if (priv->mesh_dev)
+		netif_device_attach(priv->mesh_dev);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(lbs_resume);
+
 /**
  *  @brief This function downloads firmware image, gets
  *  HW spec from firmware and set basic parameters to