watchdog: pc87413_wdt: Cleanup pc87413 watchdog driver to use

Inspired by Nat Gurumoorthy's recent patches for cleaning up the it87
drivers to use request_muxed_region for accessing the SuperIO area on
these chips, and the fact I have a GPIO driver for the pc8741x basically
ready for submission, here is a patch to cleanup the pc87413 watchdog
driver to use request_muxed_region for accessing the SuperIO area.

It also pulls out the details about the SWC IO area on initial driver
load, and properly does a request_region for that area - there's no
requirement to touch the SuperIO area after doing the initial watchdog
enable and IO base retrieval.

While I have hardware with a pc87413 on it it is not wired in a way that
allows the watchdog to reboot the machine, so I have not been able to
fully test these changes - I have checked that the driver correctly
initialises itself still and requests the SWC io region ok.

Signed-Off-By: Jonathan McDowell <noodles@earth.li>
Signed-Off-By: Wim Van Sebroeck <wim@iguana.be>

1 files changed, 50 insertions, 46 deletions

diff --git a/drivers/watchdog/pc87413_wdt.c b/drivers/watchdog/pc87413_wdt.c
index b7c139051575..e78d89986768 100644
--- a/drivers/watchdog/pc87413_wdt.c
+++ b/drivers/watchdog/pc87413_wdt.c
@@ -56,6 +56,7 @@
 #define IO_DEFAULT      0x2E            /* Address used on Portwell Boards */
 
 static int io = IO_DEFAULT;
+static int swc_base_addr = -1;
 
 static int timeout = DEFAULT_TIMEOUT;   /* timeout value */
 static unsigned long timer_enabled;     /* is the timer enabled? */
@@ -116,9 +117,8 @@ static inline void pc87413_enable_swc(void)
 
 /* Read SWC I/O base address */
 
-static inline unsigned int pc87413_get_swc_base(void)
+static void pc87413_get_swc_base_addr(void)
 {
-        unsigned int  swc_base_addr = 0;
         unsigned char addr_l, addr_h = 0;
 
         /* Step 3: Read SWC I/O Base Address */
@@ -136,12 +136,11 @@ static inline unsigned int pc87413_get_swc_base(void)
                 "Read SWC I/O Base Address: low %d, high %d, res %d\n",
                                                 addr_l, addr_h, swc_base_addr);
 #endif
-        return swc_base_addr;
 }
 
 /* Select Bank 3 of SWC */
 
-static inline void pc87413_swc_bank3(unsigned int swc_base_addr)
+static inline void pc87413_swc_bank3(void)
 {
         /* Step 4: Select Bank3 of SWC */
         outb_p(inb(swc_base_addr + 0x0f) | 0x03, swc_base_addr + 0x0f);
@@ -152,8 +151,7 @@ static inline void pc87413_swc_bank3(unsigned int swc_base_addr)
 
 /* Set watchdog timeout to x minutes */
 
-static inline void pc87413_programm_wdto(unsigned int swc_base_addr,
-                                         char pc87413_time)
+static inline void pc87413_programm_wdto(char pc87413_time)
 {
         /* Step 5: Programm WDTO, Twd. */
         outb_p(pc87413_time, swc_base_addr + WDTO);
@@ -164,7 +162,7 @@ static inline void pc87413_programm_wdto(unsigned int swc_base_addr,
 
 /* Enable WDEN */
 
-static inline void pc87413_enable_wden(unsigned int swc_base_addr)
+static inline void pc87413_enable_wden(void)
 {
         /* Step 6: Enable WDEN */
         outb_p(inb(swc_base_addr + WDCTL) | 0x01, swc_base_addr + WDCTL);
@@ -174,7 +172,7 @@ static inline void pc87413_enable_wden(unsigned int swc_base_addr)
 }
 
 /* Enable SW_WD_TREN */
-static inline void pc87413_enable_sw_wd_tren(unsigned int swc_base_addr)
+static inline void pc87413_enable_sw_wd_tren(void)
 {
         /* Enable SW_WD_TREN */
         outb_p(inb(swc_base_addr + WDCFG) | 0x80, swc_base_addr + WDCFG);
@@ -185,7 +183,7 @@ static inline void pc87413_enable_sw_wd_tren(unsigned int swc_base_addr)
 
 /* Disable SW_WD_TREN */
 
-static inline void pc87413_disable_sw_wd_tren(unsigned int swc_base_addr)
+static inline void pc87413_disable_sw_wd_tren(void)
 {
         /* Disable SW_WD_TREN */
         outb_p(inb(swc_base_addr + WDCFG) & 0x7f, swc_base_addr + WDCFG);
@@ -196,7 +194,7 @@ static inline void pc87413_disable_sw_wd_tren(unsigned int swc_base_addr)
 
 /* Enable SW_WD_TRG */
 
-static inline void pc87413_enable_sw_wd_trg(unsigned int swc_base_addr)
+static inline void pc87413_enable_sw_wd_trg(void)
 {
         /* Enable SW_WD_TRG */
         outb_p(inb(swc_base_addr + WDCTL) | 0x80, swc_base_addr + WDCTL);
@@ -207,7 +205,7 @@ static inline void pc87413_enable_sw_wd_trg(unsigned int swc_base_addr)
 
 /* Disable SW_WD_TRG */
 
-static inline void pc87413_disable_sw_wd_trg(unsigned int swc_base_addr)
+static inline void pc87413_disable_sw_wd_trg(void)
 {
         /* Disable SW_WD_TRG */
         outb_p(inb(swc_base_addr + WDCTL) & 0x7f, swc_base_addr + WDCTL);
@@ -222,18 +220,13 @@ static inline void pc87413_disable_sw_wd_trg(unsigned int swc_base_addr)
 
 static void pc87413_enable(void)
 {
-        unsigned int swc_base_addr;
-
         spin_lock(&io_lock);
 
-        pc87413_select_wdt_out();
-        pc87413_enable_swc();
-        swc_base_addr = pc87413_get_swc_base();
-        pc87413_swc_bank3(swc_base_addr);
-        pc87413_programm_wdto(swc_base_addr, timeout);
-        pc87413_enable_wden(swc_base_addr);
-        pc87413_enable_sw_wd_tren(swc_base_addr);
-        pc87413_enable_sw_wd_trg(swc_base_addr);
+        pc87413_swc_bank3();
+        pc87413_programm_wdto(timeout);
+        pc87413_enable_wden();
+        pc87413_enable_sw_wd_tren();
+        pc87413_enable_sw_wd_trg();
 
         spin_unlock(&io_lock);
 }
@@ -242,17 +235,12 @@ static void pc87413_enable(void)
 
 static void pc87413_disable(void)
 {
-        unsigned int swc_base_addr;
-
         spin_lock(&io_lock);
 
-        pc87413_select_wdt_out();
-        pc87413_enable_swc();
-        swc_base_addr = pc87413_get_swc_base();
-        pc87413_swc_bank3(swc_base_addr);
-        pc87413_disable_sw_wd_tren(swc_base_addr);
-        pc87413_disable_sw_wd_trg(swc_base_addr);
-        pc87413_programm_wdto(swc_base_addr, 0);
+        pc87413_swc_bank3();
+        pc87413_disable_sw_wd_tren();
+        pc87413_disable_sw_wd_trg();
+        pc87413_programm_wdto(0);
 
         spin_unlock(&io_lock);
 }
@@ -261,20 +249,15 @@ static void pc87413_disable(void)
 
 static void pc87413_refresh(void)
 {
-        unsigned int swc_base_addr;
-
         spin_lock(&io_lock);
 
-        pc87413_select_wdt_out();
-        pc87413_enable_swc();
-        swc_base_addr = pc87413_get_swc_base();
-        pc87413_swc_bank3(swc_base_addr);
-        pc87413_disable_sw_wd_tren(swc_base_addr);
-        pc87413_disable_sw_wd_trg(swc_base_addr);
-        pc87413_programm_wdto(swc_base_addr, timeout);
-        pc87413_enable_wden(swc_base_addr);
-        pc87413_enable_sw_wd_tren(swc_base_addr);
-        pc87413_enable_sw_wd_trg(swc_base_addr);
+        pc87413_swc_bank3();
+        pc87413_disable_sw_wd_tren();
+        pc87413_disable_sw_wd_trg();
+        pc87413_programm_wdto(timeout);
+        pc87413_enable_wden();
+        pc87413_enable_sw_wd_tren();
+        pc87413_enable_sw_wd_trg();
 
         spin_unlock(&io_lock);
 }
@@ -528,7 +511,8 @@ static int __init pc87413_init(void)
         printk(KERN_INFO PFX "Version " VERSION " at io 0x%X\n",
                                                         WDT_INDEX_IO_PORT);
 
-        /* request_region(io, 2, "pc87413"); */
+        if (!request_muxed_region(io, 2, MODNAME))
+                return -EBUSY;
 
         ret = register_reboot_notifier(&pc87413_notifier);
         if (ret != 0) {
@@ -541,12 +525,32 @@ static int __init pc87413_init(void)
                 printk(KERN_ERR PFX
                         "cannot register miscdev on minor=%d (err=%d)\n",
                         WATCHDOG_MINOR, ret);
-                unregister_reboot_notifier(&pc87413_notifier);
-                return ret;
+                goto reboot_unreg;
         }
         printk(KERN_INFO PFX "initialized. timeout=%d min \n", timeout);
+
+        pc87413_select_wdt_out();
+        pc87413_enable_swc();
+        pc87413_get_swc_base_addr();
+
+        if (!request_region(swc_base_addr, 0x20, MODNAME)) {
+                printk(KERN_ERR PFX
+                        "cannot request SWC region at 0x%x\n", swc_base_addr);
+                ret = -EBUSY;
+                goto misc_unreg;
+        }
+
         pc87413_enable();
+
+        release_region(io, 2);
         return 0;
+
+misc_unreg:
+        misc_deregister(&pc87413_miscdev);
+reboot_unreg:
+        unregister_reboot_notifier(&pc87413_notifier);
+        release_region(io, 2);
+        return ret;
 }
 
 /**
@@ -569,7 +573,7 @@ static void __exit pc87413_exit(void)
 
         misc_deregister(&pc87413_miscdev);
         unregister_reboot_notifier(&pc87413_notifier);
-        /* release_region(io, 2); */
+        release_region(swc_base_addr, 0x20);
 
         printk(KERN_INFO MODNAME " watchdog component driver removed.\n");
 }