3 files changed, 63 insertions, 5 deletions

diff --git a/drivers/parport/daisy.c b/drivers/parport/daisy.c
index 5484a46dafda..3b00e2c8e2e9 100644
--- a/drivers/parport/daisy.c
+++ b/drivers/parport/daisy.c
@@ -45,6 +45,7 @@ static struct daisydev {
 static DEFINE_SPINLOCK(topology_lock);
 
 static int numdevs;
+static bool daisy_init_done;
 
 /* Forward-declaration of lower-level functions. */
 static int mux_present(struct parport *port);
@@ -87,6 +88,24 @@ static struct parport *clone_parport(struct parport *real, int muxport)
 	return extra;
 }
 
+static int daisy_drv_probe(struct pardevice *par_dev)
+{
+	struct device_driver *drv = par_dev->dev.driver;
+
+	if (strcmp(drv->name, "daisy_drv"))
+		return -ENODEV;
+	if (strcmp(par_dev->name, daisy_dev_name))
+		return -ENODEV;
+
+	return 0;
+}
+
+static struct parport_driver daisy_driver = {
+	.name = "daisy_drv",
+	.probe = daisy_drv_probe,
+	.devmodel = true,
+};
+
 /* Discover the IEEE1284.3 topology on a port -- muxes and daisy chains.
  * Return value is number of devices actually detected. */
 int parport_daisy_init(struct parport *port)
@@ -98,6 +117,23 @@ int parport_daisy_init(struct parport *port)
 	int i;
 	int last_try = 0;
 
+	if (!daisy_init_done) {
+		/*
+		 * flag should be marked true first as
+		 * parport_register_driver() might try to load the low
+		 * level driver which will lead to announcing new ports
+		 * and which will again come back here at
+		 * parport_daisy_init()
+		 */
+		daisy_init_done = true;
+		i = parport_register_driver(&daisy_driver);
+		if (i) {
+			pr_err("daisy registration failed\n");
+			daisy_init_done = false;
+			return i;
+		}
+	}
+
 again:
 	/* Because this is called before any other devices exist,
 	 * we don't have to claim exclusive access.  */
@@ -213,10 +249,12 @@ void parport_daisy_fini(struct parport *port)
 struct pardevice *parport_open(int devnum, const char *name)
 {
 	struct daisydev *p = topology;
+	struct pardev_cb par_cb;
 	struct parport *port;
 	struct pardevice *dev;
 	int daisy;
 
+	memset(&par_cb, 0, sizeof(par_cb));
 	spin_lock(&topology_lock);
 	while (p && p->devnum != devnum)
 		p = p->next;
@@ -230,7 +268,7 @@ struct pardevice *parport_open(int devnum, const char *name)
 	port = parport_get_port(p->port);
 	spin_unlock(&topology_lock);
 
-	dev = parport_register_device(port, name, NULL, NULL, NULL, 0, NULL);
+	dev = parport_register_dev_model(port, name, &par_cb, devnum);
 	parport_put_port(port);
 	if (!dev)
 		return NULL;
diff --git a/drivers/parport/probe.c b/drivers/parport/probe.c
index e035174ba205..e5e6a463a941 100644
--- a/drivers/parport/probe.c
+++ b/drivers/parport/probe.c
@@ -257,7 +257,7 @@ static ssize_t parport_read_device_id (struct parport *port, char *buffer,
 ssize_t parport_device_id (int devnum, char *buffer, size_t count)
 {
 	ssize_t retval = -ENXIO;
-	struct pardevice *dev = parport_open (devnum, "Device ID probe");
+	struct pardevice *dev = parport_open(devnum, daisy_dev_name);
 	if (!dev)
 		return -ENXIO;
 
diff --git a/drivers/parport/share.c b/drivers/parport/share.c
index 7b4ee33c1935..d6920ebeabcd 100644
--- a/drivers/parport/share.c
+++ b/drivers/parport/share.c
@@ -230,6 +230,18 @@ static int port_check(struct device *dev, void *dev_drv)
 	return 0;
 }
 
+/*
+ * Iterates through all the devices connected to the bus and return 1
+ * if the device is a parallel port.
+ */
+
+static int port_detect(struct device *dev, void *dev_drv)
+{
+	if (is_parport(dev))
+		return 1;
+	return 0;
+}
+
 /**
  *	parport_register_driver - register a parallel port device driver
  *	@drv: structure describing the driver
@@ -266,9 +278,6 @@ static int port_check(struct device *dev, void *dev_drv)
 int __parport_register_driver(struct parport_driver *drv, struct module *owner,
 			      const char *mod_name)
 {
-	if (list_empty(&portlist))
-		get_lowlevel_driver();
-
 	if (drv->devmodel) {
 		/* using device model */
 		int ret;
@@ -282,6 +291,15 @@ int __parport_register_driver(struct parport_driver *drv, struct module *owner,
 		if (ret)
 			return ret;
 
+		/*
+		 * check if bus has any parallel port registered, if
+		 * none is found then load the lowlevel driver.
+		 */
+		ret = bus_for_each_dev(&parport_bus_type, NULL, NULL,
+				       port_detect);
+		if (!ret)
+			get_lowlevel_driver();
+
 		mutex_lock(&registration_lock);
 		if (drv->match_port)
 			bus_for_each_dev(&parport_bus_type, NULL, drv,
@@ -292,6 +310,8 @@ int __parport_register_driver(struct parport_driver *drv, struct module *owner,
 
 		drv->devmodel = false;
 
+		if (list_empty(&portlist))
+			get_lowlevel_driver();
 		mutex_lock(&registration_lock);
 		list_for_each_entry(port, &portlist, list)
 			drv->attach(port);