[PARISC] [MUX] Make the Serial Mux driver work as module

The following updates are based off a patch from willy:
  * Removal of the mux_card list.
  * Add the mux_remove function.

Other updates:
  * Re-organize the driver structure a bit to make the
    mux_init and mux_exit functions more symmetrical.
  * Added the del_timer.
  * Unregistered the console.

At this point I can insmod, rmmod, and re-insmod the
mux without any failures.

Signed-off-by: Ryan Bradetich <rbrad@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>

1 files changed, 57 insertions, 78 deletions

diff --git a/drivers/serial/mux.c b/drivers/serial/mux.c
index f21faf163955..5ff7e05a1526 100644
--- a/drivers/serial/mux.c
+++ b/drivers/serial/mux.c
@@ -66,13 +66,6 @@ static struct uart_driver mux_driver = {
         .nr = MUX_NR,
 };
 
-struct mux_card {
-        int port_count;
-        struct parisc_device *dev;
-        struct mux_card *next;
-};
-
-static struct mux_card *mux_card_head;
 static struct timer_list mux_timer;
 
 #define UART_PUT_CHAR(p, c) __raw_writel((c), (p)->membase + IO_DATA_REG_OFFSET)
@@ -441,37 +434,6 @@ static struct uart_ops mux_pops = {
 };
 
 /**
- * get_new_mux_card - Allocate and return a new mux card.
- *
- * This function is used to allocate and return a new mux card.
- */
-static struct mux_card * __init get_new_mux_card(void)
-{
-        struct mux_card *card = mux_card_head;
-
-        if(card == NULL) {
-                mux_card_head = kzalloc(sizeof(struct mux_card), GFP_KERNEL);
-                if(!mux_card_head) {
-                        printk(KERN_ERR "MUX: Unable to allocate memory.\n");
-                        return NULL;
-                }
-                return mux_card_head;
-        }
-
-        while(card->next) {
-                card = card->next;
-        }
-
-        card->next = kzalloc(sizeof(struct mux_card), GFP_KERNEL);
-        if(!card->next) {
-                printk(KERN_ERR "MUX: Unable to allocate memory.\n");
-                return NULL;
-        }
-
-        return card->next;
-}
-
-/**
  * mux_probe - Determine if the Serial Mux should claim this device.
  * @dev: The parisc device.
  *
@@ -480,11 +442,9 @@ static struct mux_card * __init get_new_mux_card(void)
  */
 static int __init mux_probe(struct parisc_device *dev)
 {
-        int i, status, ports;
+        int i, status, port_count;
         u8 iodc_data[32];
         unsigned long bytecnt;
-        struct uart_port *port;
-        struct mux_card *card;
 
         status = pdc_iodc_read(&bytecnt, dev->hpa.start, 0, iodc_data, 32);
         if(status != PDC_OK) {
@@ -492,17 +452,12 @@ static int __init mux_probe(struct parisc_device *dev)
                 return 1;
         }
 
-        ports = GET_MUX_PORTS(iodc_data);
-        printk(KERN_INFO "Serial mux driver (%d ports) Revision: 0.4\n", ports);
+        port_count = GET_MUX_PORTS(iodc_data);
+        printk(KERN_INFO "Serial mux driver (%d ports) Revision: 0.5\n", port_count);
 
-        card = get_new_mux_card();
-        if(card == NULL)
-                return 1;
-
-        card->dev = dev;
-        card->port_count = ports;
-        request_mem_region(card->dev->hpa.start + MUX_OFFSET,
-                card->port_count * MUX_LINE_OFFSET, "Mux");
+        dev_set_drvdata(&dev->dev, (void *)(long)port_count);
+        request_mem_region(dev->hpa.start + MUX_OFFSET,
+                           port_count * MUX_LINE_OFFSET, "Mux");
 
         if(!port_cnt) {
                 mux_driver.cons = MUX_CONSOLE;
@@ -512,13 +467,10 @@ static int __init mux_probe(struct parisc_device *dev)
                         printk(KERN_ERR "Serial mux: Unable to register driver.\n");
                         return 1;
                 }
-
-                init_timer(&mux_timer);
-                mux_timer.function = mux_poll;
         }
 
-        for(i = 0; i < ports; ++i, ++port_cnt) {
-                port = &mux_ports[port_cnt].port;
+        for(i = 0; i < port_count; ++i, ++port_cnt) {
+                struct uart_port *port = &mux_ports[port_cnt].port;
                 port->iobase    = 0;
                 port->mapbase   = dev->hpa.start + MUX_OFFSET +
                                                 (i * MUX_LINE_OFFSET);
@@ -543,11 +495,34 @@ static int __init mux_probe(struct parisc_device *dev)
                 BUG_ON(status);
         }
 
-#ifdef CONFIG_SERIAL_MUX_CONSOLE
-        register_console(&mux_console);
-#endif
-        mod_timer(&mux_timer, jiffies + MUX_POLL_DELAY);
+        return 0;
+}
 
+static int __devexit mux_remove(struct parisc_device *dev)
+{
+        int i;
+        int port_count = (long)dev_get_drvdata(&dev->dev);
+
+        /* Delete the Mux timer. */
+        del_timer(&mux_timer);
+
+        /* Find Port 0 for this card in the mux_ports list. */
+        for(i = 0; i < port_cnt; ++i) {
+                if(mux_ports[i].port.mapbase == dev->hpa.start + MUX_OFFSET)
+                        break;
+        }
+        BUG_ON(i + port_count > port_cnt);
+
+        /* Release the resources associated with each port on the device. */
+        for(; i < port_count; ++i) {
+                struct uart_port *port = &mux_ports[i].port;
+
+                uart_remove_one_port(&mux_driver, port);
+                if(port->membase)
+                        iounmap(port->membase);
+        }
+
+        release_mem_region(dev->hpa.start + MUX_OFFSET, port_count * MUX_LINE_OFFSET);
         return 0;
 }
 
@@ -562,6 +537,7 @@ static struct parisc_driver serial_mux_driver = {
         .name =         "serial_mux",
         .id_table =     mux_tbl,
         .probe =        mux_probe,
+        .remove =       __devexit_p(mux_remove),
 };
 
 /**
@@ -571,7 +547,20 @@ static struct parisc_driver serial_mux_driver = {
  */
 static int __init mux_init(void)
 {
-        return register_parisc_driver(&serial_mux_driver);
+        int status = register_parisc_driver(&serial_mux_driver);
+
+        if(port_cnt > 0) {
+                /* Start the Mux timer */
+                init_timer(&mux_timer);
+                mux_timer.function = mux_poll;
+                mod_timer(&mux_timer, jiffies + MUX_POLL_DELAY);
+
+#ifdef CONFIG_SERIAL_MUX_CONSOLE
+                register_console(&mux_console);
+#endif
+        }
+
+        return status;
 }
 
 /**
@@ -581,25 +570,15 @@ static int __init mux_init(void)
  */
 static void __exit mux_exit(void)
 {
-        int i;
-        struct mux_card *next;
-        struct mux_card *card = mux_card_head;
-
-        for (i = 0; i < port_cnt; i++) {
-                uart_remove_one_port(&mux_driver, &mux_ports[i].port);
-                if (mux_ports[i].port.membase)
-                        iounmap(mux_ports[i].port.membase);
-        }
-
-        while(card != NULL) {
-                release_mem_region(card->dev->hpa.start + MUX_OFFSET,
-                                   card->port_count * MUX_LINE_OFFSET);
-
-                next = card->next;
-                kfree(card);
-                card = next;
+        /* Delete the Mux timer. */
+        if(port_cnt > 0) {
+                del_timer(&mux_timer);
+#ifdef CONFIG_SERIAL_MUX_CONSOLE
+                unregister_console(&mux_console);
+#endif
         }
 
+        unregister_parisc_driver(&serial_mux_driver);
         uart_unregister_driver(&mux_driver);
 }