[PATCH 1/5] char: lp: introduce list to save port number

[PATCH 1/5] char: lp: introduce list to save port number

[Sudip Mukherjee]

When we are registering lp in LP_PARPORT_AUTO mode, we are not keeping
any record of the parallel port number to which lp is connecting.
Add an array to save the port number to it.

Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
---
 drivers/char/lp.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/char/lp.c b/drivers/char/lp.c
index e0a92d764eee..7e207ff0f2fe 100644
--- a/drivers/char/lp.c
+++ b/drivers/char/lp.c
@@ -141,6 +141,7 @@
 
 static DEFINE_MUTEX(lp_mutex);
 static struct lp_struct lp_table[LP_NO];
+static int port_num[LP_NO];
 
 static unsigned int lp_count = 0;
 static struct class *lp_class;
@@ -938,6 +939,7 @@ static int lp_register(int nr, struct parport *port)
 			       CONSOLE_LP, port->name);
 	}
 #endif
+	port_num[nr] = port->number;
 
 	return 0;
 }
@@ -1013,6 +1015,7 @@ static int __init lp_init(void)
 		init_waitqueue_head(&lp_table[i].dataq);
 		mutex_init(&lp_table[i].port_mutex);
 		lp_table[i].timeout = 10 * HZ;
+		port_num[i] = -1;
 	}
 
 	if (register_chrdev(LP_MAJOR, "lp", &lp_fops)) {
@@ -1091,6 +1094,7 @@ static void lp_cleanup_module(void)
 	for (offset = 0; offset < LP_NO; offset++) {
 		if (lp_table[offset].dev == NULL)
 			continue;
+		port_num[offset] = -1;
 		parport_unregister_device(lp_table[offset].dev);
 		device_destroy(lp_class, MKDEV(LP_MAJOR, offset));
 	}
-- 
2.11.0

[PATCH 2/5] char: lp: detach the device when parallel port is removed

[Sudip Mukherjee]

When the parallel port is usb based and the lp attaches to it, we do
get /dev/lp0, but when we remove the usb device and the parallel port
is gone, we are still left with /dev/lp0.
Unregister the device properly in the detach routine based on the port
number it has connected to.

Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
---
 drivers/char/lp.c | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/drivers/char/lp.c b/drivers/char/lp.c
index 7e207ff0f2fe..e21ed4007d0f 100644
--- a/drivers/char/lp.c
+++ b/drivers/char/lp.c
@@ -976,6 +976,8 @@ static void lp_attach(struct parport *port)
 
 static void lp_detach(struct parport *port)
 {
+	int n;
+
 	/* Write this some day. */
 #ifdef CONFIG_LP_CONSOLE
 	if (console_registered == port) {
@@ -983,6 +985,14 @@ static void lp_detach(struct parport *port)
 		console_registered = NULL;
 	}
 #endif /* CONFIG_LP_CONSOLE */
+
+	for (n = 0; n < LP_NO; n++) {
+		if (port_num[n] == port->number) {
+			port_num[n] = -1;
+			device_destroy(lp_class, MKDEV(LP_MAJOR, n));
+			parport_unregister_device(lp_table[n].dev);
+		}
+	}
 }
 
 static struct parport_driver lp_driver = {
@@ -1082,8 +1092,6 @@ static int __init lp_init_module(void)
 
 static void lp_cleanup_module(void)
 {
-	unsigned int offset;
-
 	parport_unregister_driver(&lp_driver);
 
 #ifdef CONFIG_LP_CONSOLE
@@ -1091,13 +1099,6 @@ static void lp_cleanup_module(void)
 #endif
 
 	unregister_chrdev(LP_MAJOR, "lp");
-	for (offset = 0; offset < LP_NO; offset++) {
-		if (lp_table[offset].dev == NULL)
-			continue;
-		port_num[offset] = -1;
-		parport_unregister_device(lp_table[offset].dev);
-		device_destroy(lp_class, MKDEV(LP_MAJOR, offset));
-	}
 	class_destroy(lp_class);
 }
 
-- 
2.11.0

[PATCH 3/5] char: lp: use first unused lp number while registering

[Sudip Mukherjee]

When the parallel port is usb based and the lp attaches to it based on
LP_PARPORT_AUTO, we do get /dev/lp0 and when we remove the usb device
/dev/lp0 is unregistered. But if we now reconnect the usb device we get
/dev/lp1, another disconnection and reconnection and we get /dev/lp2.

Use the port number array to find the first unused lp number and use
that to register the lp device with the parallel port.

Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
---
 drivers/char/lp.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/char/lp.c b/drivers/char/lp.c
index e21ed4007d0f..0e081f521f51 100644
--- a/drivers/char/lp.c
+++ b/drivers/char/lp.c
@@ -958,7 +958,11 @@ static void lp_attach(struct parport *port)
 			printk(KERN_INFO "lp: ignoring parallel port (max. %d)\n",LP_NO);
 			return;
 		}
-		if (!lp_register(lp_count, port))
+		for (i = 0; i < LP_NO; i++)
+			if (port_num[i] == -1)
+				break;
+
+		if (!lp_register(i, port))
 			lp_count++;
 		break;
 
-- 
2.11.0

[PATCH 4/5] char: lp: properly count the lp devices

[Sudip Mukherjee]

When the parallel port is usb based and the lp attaches to it based on
LP_PARPORT_AUTO, we do get /dev/lp0 and when we remove the usb device
/dev/lp0 is unregistered. If we now reconnect the usb device we get
our /dev/lp0 back. But if we now disconnect and reconnect eight times
we donot get any lp device and dmesg shows:

    lp: ignoring parallel port (max. 8)

Decrement the lp_count when the device detaches as this represents the
number of lp devices connected to the system.

Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
---
 drivers/char/lp.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/char/lp.c b/drivers/char/lp.c
index 0e081f521f51..cef2ea386f5e 100644
--- a/drivers/char/lp.c
+++ b/drivers/char/lp.c
@@ -993,6 +993,7 @@ static void lp_detach(struct parport *port)
 	for (n = 0; n < LP_NO; n++) {
 		if (port_num[n] == port->number) {
 			port_num[n] = -1;
+			lp_count--;
 			device_destroy(lp_class, MKDEV(LP_MAJOR, n));
 			parport_unregister_device(lp_table[n].dev);
 		}
-- 
2.11.0

[PATCH 5/5] char: lp: use new parport device model

[Sudip Mukherjee]

Modify lp driver to use the new parallel port device model.

Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
---
 drivers/char/lp.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/drivers/char/lp.c b/drivers/char/lp.c
index cef2ea386f5e..5c8d780637bd 100644
--- a/drivers/char/lp.c
+++ b/drivers/char/lp.c
@@ -912,9 +912,13 @@ static int __init lp_setup(char *str)
 
 static int lp_register(int nr, struct parport *port)
 {
-	lp_table[nr].dev = parport_register_device(port, "lp",
-						   lp_preempt, NULL, NULL, 0,
-						   (void *) &lp_table[nr]);
+	struct pardev_cb ppdev_cb;
+
+	memset(&ppdev_cb, 0, sizeof(ppdev_cb));
+	ppdev_cb.preempt = lp_preempt;
+	ppdev_cb.private = &lp_table[nr];
+	lp_table[nr].dev = parport_register_dev_model(port, "lp",
+						      &ppdev_cb, nr);
 	if (lp_table[nr].dev == NULL)
 		return 1;
 	lp_table[nr].flags |= LP_EXIST;
@@ -1002,8 +1006,9 @@ static void lp_detach(struct parport *port)
 
 static struct parport_driver lp_driver = {
 	.name = "lp",
-	.attach = lp_attach,
+	.match_port = lp_attach,
 	.detach = lp_detach,
+	.devmodel = true,
 };
 
 static int __init lp_init(void)
-- 
2.11.0