watchdog: sp5100_tco: Add SB8x0 chipset support

The current sp5100_tco driver only supports SP5100/SB7x0 chipset, doesn't
support SB8x0 chipset, because current sp5100_tco driver doesn't know that the
offset address for watchdog timer was changed from SB8x0 chipset.

The offset address of SP5100 and SB7x0 chipsets are as follows, quote from the
AMD SB700/710/750 Register Reference Guide (Page 164) and the AMD SP5100
Register Reference Guide (Page 166).

  WatchDogTimerControl 69h
  WatchDogTimerBase0   6Ch
  WatchDogTimerBase1   6Dh
  WatchDogTimerBase2   6Eh
  WatchDogTimerBase3   6Fh

In contrast, the offset address of SB8x0 chipset is as follows, quote from
AMD SB800-Series Southbridges Register Reference Guide (Page 147).

  WatchDogTimerEn      48h
  WatchDogTimerConfig  4Ch

So, In the case of SB8x0 chipset, sp5100_tco reads meaningless MMIO
address (for example, 0xbafe00) from wrong offset address, and the following
message is logged.

   SP5100 TCO timer: mmio address 0xbafe00 already in use

With this patch, sp5100_tco driver supports SB8x0 chipset, and can avoid
iomem resource conflict. The processing of this patch is as follows.

 Step 1) Attempt to get the watchdog base address from indirect I/O (0xCD6
         and 0xCD7).
  - Go to the step 7 if obtained address hasn't conflicted with other
    resource. But, currently, the address (0xfec000f0) conflicts with the
    IOAPIC MMIO address, and the following message is logged.

       SP5100 TCO timer: mmio address 0xfec000f0 already in use

    0xfec000f0 is recommended by AMD BIOS Developer's Guide. So, go to the
    next step.

 Step 2) Attempt to get the SBResource_MMIO base address from AcpiMmioEN (for
         SB8x0,  PM_Reg:24h) or SBResource_MMIO (SP5100/SB7x0, PCI_Reg:9Ch)
         register.
  - Go to the step 7 if these register has enabled by BIOS, and obtained
    address hasn't conflicted with other resource.
  - If above condition isn't true, go to the next step.

 Step 3) Attempt to get the free MMIO address from allocate_resource().
  - Go to the step 7 if these register has enabled by BIOS, and obtained
    address hasn't conflicted with other resource.
  - Driver initialization has failed if obtained address has conflicted
    with other resource, and no 'force_addr' parameter is specified.

 Step 4) Use the specified address If 'force_addr' parameter is specified.
  - allocate_resource() function may fail, when the PCI bridge device occupies
    iomem resource from 0xf0000000 to 0xffffffff. To handle such a case,
    I added 'force_addr' parameter to sp5100_tco driver. With 'force_addr'
    parameter, sp5100_tco driver directly can assign MMIO address for watchdog
    timer from free iomem region. Note that It's dangerous to specify wrong
    address in the 'force_addr' parameter.

      Example of force_addr parameter use
        # cat /proc/iomem
        ...snip...
        fec00000-fec003ff : IOAPIC 0
                                      <--- free MMIO region
        fec10000-fec1001f : pnp 00:0b
        fec20000-fec203ff : IOAPIC 1
        ...snip...
        # cat /etc/modprobe.d/sp5100_tco.conf
        options sp5100_tco force_addr=0xfec00800
        # modprobe sp5100_tco
        # cat /proc/iomem
        ...snip...
        fec00000-fec003ff : IOAPIC 0
        fec00800-fec00807 : SP5100 TCO  <--- watchdog timer MMIO address
        fec10000-fec1001f : pnp 00:0b
        fec20000-fec203ff : IOAPIC 1
        ...snip...
        #

  - Driver initialization has failed if specified address has conflicted
    with other resource.

 Step 5) Disable the watchdog timer
  - To rewrite the watchdog timer register of the chipset, absolutely
    guarantee that the watchdog timer is disabled.

 Step 6) Re-program the watchdog timer MMIO address to chipset.
  - Re-program the obtained MMIO address in Step 3 or Step 4 to chipset via
    indirect I/O (0xCD6 and 0xCD7).

 Step 7) Enable and setup the watchdog timer

This patch has worked fine on my test environment (ASUS M4A89GTD-PRO/USB3 and
DL165G7). therefore I believe that it's no problem to re-program the MMIO
address for watchdog timer to chipset during disabled watchdog. However,
I'm not sure about it, because I don't know much about chipset programming.

So, any comments will be welcome.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=43176
Tested-by: Arkadiusz Miskiewicz <arekm@maven.pl>
Tested-by: Paul Menzel <paulepanter@users.sourceforge.net>
Signed-off-by: Takahisa Tanaka <mc74hc00@gmail.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

2 files changed, 306 insertions, 61 deletions

diff --git a/drivers/watchdog/sp5100_tco.c b/drivers/watchdog/sp5100_tco.c
index b3876812ff07..2b0e000d4377 100644
--- a/drivers/watchdog/sp5100_tco.c
+++ b/drivers/watchdog/sp5100_tco.c
@@ -13,7 +13,9 @@
  *      as published by the Free Software Foundation; either version
  *      2 of the License, or (at your option) any later version.
  *
- *      See AMD Publication 43009 "AMD SB700/710/750 Register Reference Guide"
+ *      See AMD Publication 43009 "AMD SB700/710/750 Register Reference Guide",
+ *          AMD Publication 45482 "AMD SB800-Series Southbridges Register
+ *                                                            Reference Guide"
  */
 
 /*
@@ -38,18 +40,24 @@
 #include "sp5100_tco.h"
 
 /* Module and version information */
-#define TCO_VERSION "0.01"
+#define TCO_VERSION "0.03"
 #define TCO_MODULE_NAME "SP5100 TCO timer"
 #define TCO_DRIVER_NAME   TCO_MODULE_NAME ", v" TCO_VERSION
 
 /* internal variables */
 static u32 tcobase_phys;
+static u32 resbase_phys;
+static u32 tco_wdt_fired;
 static void __iomem *tcobase;
 static unsigned int pm_iobase;
 static DEFINE_SPINLOCK(tco_lock);       /* Guards the hardware */
 static unsigned long timer_alive;
 static char tco_expect_close;
 static struct pci_dev *sp5100_tco_pci;
+static struct resource wdt_res = {
+        .name = "Watchdog Timer",
+        .flags = IORESOURCE_MEM,
+};
 
 /* the watchdog platform device */
 static struct platform_device *sp5100_tco_platform_device;
@@ -64,9 +72,15 @@ MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. (default="
 
 static bool nowayout = WATCHDOG_NOWAYOUT;
 module_param(nowayout, bool, 0);
-MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started"
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started."
                 " (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
 
+static unsigned int force_addr;
+module_param(force_addr, uint, 0);
+MODULE_PARM_DESC(force_addr, "Force the use of specified MMIO address."
+                " ONLY USE THIS PARAMETER IF YOU REALLY KNOW"
+                " WHAT YOU ARE DOING (default=none)");
+
 /*
  * Some TCO specific functions
  */
@@ -122,6 +136,79 @@ static int tco_timer_set_heartbeat(int t)
         return 0;
 }
 
+static void tco_timer_enable(void)
+{
+        int val;
+
+        if (sp5100_tco_pci->revision >= 0x40) {
+                /* For SB800 or later */
+                /* Set the Watchdog timer resolution to 1 sec */
+                outb(SB800_PM_WATCHDOG_CONFIG, SB800_IO_PM_INDEX_REG);
+                val = inb(SB800_IO_PM_DATA_REG);
+                val |= SB800_PM_WATCHDOG_SECOND_RES;
+                outb(val, SB800_IO_PM_DATA_REG);
+
+                /* Enable watchdog decode bit and watchdog timer */
+                outb(SB800_PM_WATCHDOG_CONTROL, SB800_IO_PM_INDEX_REG);
+                val = inb(SB800_IO_PM_DATA_REG);
+                val |= SB800_PCI_WATCHDOG_DECODE_EN;
+                val &= ~SB800_PM_WATCHDOG_DISABLE;
+                outb(val, SB800_IO_PM_DATA_REG);
+        } else {
+                /* For SP5100 or SB7x0 */
+                /* Enable watchdog decode bit */
+                pci_read_config_dword(sp5100_tco_pci,
+                                      SP5100_PCI_WATCHDOG_MISC_REG,
+                                      &val);
+
+                val |= SP5100_PCI_WATCHDOG_DECODE_EN;
+
+                pci_write_config_dword(sp5100_tco_pci,
+                                       SP5100_PCI_WATCHDOG_MISC_REG,
+                                       val);
+
+                /* Enable Watchdog timer and set the resolution to 1 sec */
+                outb(SP5100_PM_WATCHDOG_CONTROL, SP5100_IO_PM_INDEX_REG);
+                val = inb(SP5100_IO_PM_DATA_REG);
+                val |= SP5100_PM_WATCHDOG_SECOND_RES;
+                val &= ~SP5100_PM_WATCHDOG_DISABLE;
+                outb(val, SP5100_IO_PM_DATA_REG);
+        }
+}
+
+static void tco_timer_disable(void)
+{
+        int val;
+
+        if (sp5100_tco_pci->revision >= 0x40) {
+                /* For SB800 or later */
+                /* Enable watchdog decode bit and Disable watchdog timer */
+                outb(SB800_PM_WATCHDOG_CONTROL, SB800_IO_PM_INDEX_REG);
+                val = inb(SB800_IO_PM_DATA_REG);
+                val |= SB800_PCI_WATCHDOG_DECODE_EN;
+                val |= SB800_PM_WATCHDOG_DISABLE;
+                outb(val, SB800_IO_PM_DATA_REG);
+        } else {
+                /* For SP5100 or SB7x0 */
+                /* Enable watchdog decode bit */
+                pci_read_config_dword(sp5100_tco_pci,
+                                      SP5100_PCI_WATCHDOG_MISC_REG,
+                                      &val);
+
+                val |= SP5100_PCI_WATCHDOG_DECODE_EN;
+
+                pci_write_config_dword(sp5100_tco_pci,
+                                       SP5100_PCI_WATCHDOG_MISC_REG,
+                                       val);
+
+                /* Disable Watchdog timer */
+                outb(SP5100_PM_WATCHDOG_CONTROL, SP5100_IO_PM_INDEX_REG);
+                val = inb(SP5100_IO_PM_DATA_REG);
+                val |= SP5100_PM_WATCHDOG_DISABLE;
+                outb(val, SP5100_IO_PM_DATA_REG);
+        }
+}
+
 /*
  *      /dev/watchdog handling
  */
@@ -270,11 +357,12 @@ MODULE_DEVICE_TABLE(pci, sp5100_tco_pci_tbl);
 /*
  * Init & exit routines
  */
-
 static unsigned char sp5100_tco_setupdevice(void)
 {
         struct pci_dev *dev = NULL;
+        const char *dev_name = NULL;
         u32 val;
+        u32 index_reg, data_reg, base_addr;
 
         /* Match the PCI device */
         for_each_pci_dev(dev) {
@@ -287,29 +375,160 @@ static unsigned char sp5100_tco_setupdevice(void)
         if (!sp5100_tco_pci)
                 return 0;
 
+        pr_info("PCI Revision ID: 0x%x\n", sp5100_tco_pci->revision);
+
+        /*
+         * Determine type of southbridge chipset.
+         */
+        if (sp5100_tco_pci->revision >= 0x40) {
+                dev_name = SB800_DEVNAME;
+                index_reg = SB800_IO_PM_INDEX_REG;
+                data_reg = SB800_IO_PM_DATA_REG;
+                base_addr = SB800_PM_WATCHDOG_BASE;
+        } else {
+                dev_name = SP5100_DEVNAME;
+                index_reg = SP5100_IO_PM_INDEX_REG;
+                data_reg = SP5100_IO_PM_DATA_REG;
+                base_addr = SP5100_PM_WATCHDOG_BASE;
+        }
+
         /* Request the IO ports used by this driver */
         pm_iobase = SP5100_IO_PM_INDEX_REG;
-        if (!request_region(pm_iobase, SP5100_PM_IOPORTS_SIZE, "SP5100 TCO")) {
+        if (!request_region(pm_iobase, SP5100_PM_IOPORTS_SIZE, dev_name)) {
                 pr_err("I/O address 0x%04x already in use\n", pm_iobase);
                 goto exit;
         }
 
-        /* Find the watchdog base address. */
-        outb(SP5100_PM_WATCHDOG_BASE3, SP5100_IO_PM_INDEX_REG);
-        val = inb(SP5100_IO_PM_DATA_REG);
-        outb(SP5100_PM_WATCHDOG_BASE2, SP5100_IO_PM_INDEX_REG);
-        val = val << 8 | inb(SP5100_IO_PM_DATA_REG);
-        outb(SP5100_PM_WATCHDOG_BASE1, SP5100_IO_PM_INDEX_REG);
-        val = val << 8 | inb(SP5100_IO_PM_DATA_REG);
-        outb(SP5100_PM_WATCHDOG_BASE0, SP5100_IO_PM_INDEX_REG);
-        /* Low three bits of BASE0 are reserved. */
-        val = val << 8 | (inb(SP5100_IO_PM_DATA_REG) & 0xf8);
+        /*
+         * First, Find the watchdog timer MMIO address from indirect I/O.
+         */
+        outb(base_addr+3, index_reg);
+        val = inb(data_reg);
+        outb(base_addr+2, index_reg);
+        val = val << 8 | inb(data_reg);
+        outb(base_addr+1, index_reg);
+        val = val << 8 | inb(data_reg);
+        outb(base_addr+0, index_reg);
+        /* Low three bits of BASE are reserved */
+        val = val << 8 | (inb(data_reg) & 0xf8);
+
+        pr_debug("Got 0x%04x from indirect I/O\n", val);
+
+        /* Check MMIO address conflict */
+        if (request_mem_region_exclusive(val, SP5100_WDT_MEM_MAP_SIZE,
+                                                                dev_name))
+                goto setup_wdt;
+        else
+                pr_debug("MMIO address 0x%04x already in use\n", val);
+
+        /*
+         * Secondly, Find the watchdog timer MMIO address
+         * from SBResource_MMIO register.
+         */
+        if (sp5100_tco_pci->revision >= 0x40) {
+                /* Read SBResource_MMIO from AcpiMmioEn(PM_Reg: 24h) */
+                outb(SB800_PM_ACPI_MMIO_EN+3, SB800_IO_PM_INDEX_REG);
+                val = inb(SB800_IO_PM_DATA_REG);
+                outb(SB800_PM_ACPI_MMIO_EN+2, SB800_IO_PM_INDEX_REG);
+                val = val << 8 | inb(SB800_IO_PM_DATA_REG);
+                outb(SB800_PM_ACPI_MMIO_EN+1, SB800_IO_PM_INDEX_REG);
+                val = val << 8 | inb(SB800_IO_PM_DATA_REG);
+                outb(SB800_PM_ACPI_MMIO_EN+0, SB800_IO_PM_INDEX_REG);
+                val = val << 8 | inb(SB800_IO_PM_DATA_REG);
+        } else {
+                /* Read SBResource_MMIO from PCI config(PCI_Reg: 9Ch) */
+                pci_read_config_dword(sp5100_tco_pci,
+                                      SP5100_SB_RESOURCE_MMIO_BASE, &val);
+        }
+
+        /* The SBResource_MMIO is enabled and mapped memory space? */
+        if ((val & (SB800_ACPI_MMIO_DECODE_EN | SB800_ACPI_MMIO_SEL)) ==
+                                                  SB800_ACPI_MMIO_DECODE_EN) {
+                /* Clear unnecessary the low twelve bits */
+                val &= ~0xFFF;
+                /* Add the Watchdog Timer offset to base address. */
+                val += SB800_PM_WDT_MMIO_OFFSET;
+                /* Check MMIO address conflict */
+                if (request_mem_region_exclusive(val, SP5100_WDT_MEM_MAP_SIZE,
+                                                                   dev_name)) {
+                        pr_debug("Got 0x%04x from SBResource_MMIO register\n",
+                                val);
+                        goto setup_wdt;
+                } else
+                        pr_debug("MMIO address 0x%04x already in use\n", val);
+        } else
+                pr_debug("SBResource_MMIO is disabled(0x%04x)\n", val);
+
+        /*
+         * Lastly re-programming the watchdog timer MMIO address,
+         * This method is a last resort...
+         *
+         * Before re-programming, to ensure that the watchdog timer
+         * is disabled, disable the watchdog timer.
+         */
+        tco_timer_disable();
+
+        if (force_addr) {
+                /*
+                 * Force the use of watchdog timer MMIO address, and aligned to
+                 * 8byte boundary.
+                 */
+                force_addr &= ~0x7;
+                val = force_addr;
+
+                pr_info("Force the use of 0x%04x as MMIO address\n", val);
+        } else {
+                /*
+                 * Get empty slot into the resource tree for watchdog timer.
+                 */
+                if (allocate_resource(&iomem_resource,
+                                      &wdt_res,
+                                      SP5100_WDT_MEM_MAP_SIZE,
+                                      0xf0000000,
+                                      0xfffffff8,
+                                      0x8,
+                                      NULL,
+                                      NULL)) {
+                        pr_err("MMIO allocation failed\n");
+                        goto unreg_region;
+                }
+
+                val = resbase_phys = wdt_res.start;
+                pr_debug("Got 0x%04x from resource tree\n", val);
+        }
+
+        /* Restore to the low three bits, if chipset is SB8x0(or later) */
+        if (sp5100_tco_pci->revision >= 0x40) {
+                u8 reserved_bit;
+                reserved_bit = inb(base_addr) & 0x7;
+                val |= (u32)reserved_bit;
+        }
+
+        /* Re-programming the watchdog timer base address */
+        outb(base_addr+0, index_reg);
+        /* Low three bits of BASE are reserved */
+        outb((val >>  0) & 0xf8, data_reg);
+        outb(base_addr+1, index_reg);
+        outb((val >>  8) & 0xff, data_reg);
+        outb(base_addr+2, index_reg);
+        outb((val >> 16) & 0xff, data_reg);
+        outb(base_addr+3, index_reg);
+        outb((val >> 24) & 0xff, data_reg);
+
+        /*
+         * Clear unnecessary the low three bits,
+         * if chipset is SB8x0(or later)
+         */
+        if (sp5100_tco_pci->revision >= 0x40)
+                val &= ~0x7;
 
         if (!request_mem_region_exclusive(val, SP5100_WDT_MEM_MAP_SIZE,
-                                                                "SP5100 TCO")) {
-                pr_err("mmio address 0x%04x already in use\n", val);
-                goto unreg_region;
+                                                                   dev_name)) {
+                pr_err("MMIO address 0x%04x already in use\n", val);
+                goto unreg_resource;
         }
+
+setup_wdt:
         tcobase_phys = val;
 
         tcobase = ioremap(val, SP5100_WDT_MEM_MAP_SIZE);
@@ -318,26 +537,18 @@ static unsigned char sp5100_tco_setupdevice(void)
                 goto unreg_mem_region;
         }
 
-        /* Enable watchdog decode bit */
-        pci_read_config_dword(sp5100_tco_pci,
-                              SP5100_PCI_WATCHDOG_MISC_REG,
-                              &val);
-
-        val |= SP5100_PCI_WATCHDOG_DECODE_EN;
+        pr_info("Using 0x%04x for watchdog MMIO address\n", val);
 
-        pci_write_config_dword(sp5100_tco_pci,
-                               SP5100_PCI_WATCHDOG_MISC_REG,
-                               val);
+        /* Setup the watchdog timer */
+        tco_timer_enable();
 
-        /* Enable Watchdog timer and set the resolution to 1 sec. */
-        outb(SP5100_PM_WATCHDOG_CONTROL, SP5100_IO_PM_INDEX_REG);
-        val = inb(SP5100_IO_PM_DATA_REG);
-        val |= SP5100_PM_WATCHDOG_SECOND_RES;
-        val &= ~SP5100_PM_WATCHDOG_DISABLE;
-        outb(val, SP5100_IO_PM_DATA_REG);
-
-        /* Check that the watchdog action is set to reset the system. */
+        /* Check that the watchdog action is set to reset the system */
         val = readl(SP5100_WDT_CONTROL(tcobase));
+        /*
+         * Save WatchDogFired status, because WatchDogFired flag is
+         * cleared here.
+         */
+        tco_wdt_fired = val & SP5100_PM_WATCHDOG_FIRED;
         val &= ~SP5100_PM_WATCHDOG_ACTION_RESET;
         writel(val, SP5100_WDT_CONTROL(tcobase));
 
@@ -355,6 +566,9 @@ static unsigned char sp5100_tco_setupdevice(void)
 
 unreg_mem_region:
         release_mem_region(tcobase_phys, SP5100_WDT_MEM_MAP_SIZE);
+unreg_resource:
+        if (resbase_phys)
+                release_resource(&wdt_res);
 unreg_region:
         release_region(pm_iobase, SP5100_PM_IOPORTS_SIZE);
 exit:
@@ -364,23 +578,18 @@ exit:
 static int sp5100_tco_init(struct platform_device *dev)
 {
         int ret;
-        u32 val;
+        char addr_str[16];
 
-        /* Check whether or not the hardware watchdog is there. If found, then
+        /*
+         * Check whether or not the hardware watchdog is there. If found, then
          * set it up.
          */
         if (!sp5100_tco_setupdevice())
                 return -ENODEV;
 
         /* Check to see if last reboot was due to watchdog timeout */
-        pr_info("Watchdog reboot %sdetected\n",
-                readl(SP5100_WDT_CONTROL(tcobase)) & SP5100_PM_WATCHDOG_FIRED ?
-                "" : "not ");
-
-        /* Clear out the old status */
-        val = readl(SP5100_WDT_CONTROL(tcobase));
-        val &= ~SP5100_PM_WATCHDOG_FIRED;
-        writel(val, SP5100_WDT_CONTROL(tcobase));
+        pr_info("Last reboot was %striggered by watchdog.\n",
+                tco_wdt_fired ? "" : "not ");
 
         /*
          * Check that the heartbeat value is within it's range.
@@ -400,14 +609,24 @@ static int sp5100_tco_init(struct platform_device *dev)
 
         clear_bit(0, &timer_alive);
 
-        pr_info("initialized (0x%p). heartbeat=%d sec (nowayout=%d)\n",
-                tcobase, heartbeat, nowayout);
+        /* Show module parameters */
+        if (force_addr == tcobase_phys)
+                /* The force_addr is vaild */
+                sprintf(addr_str, "0x%04x", force_addr);
+        else
+                strcpy(addr_str, "none");
+
+        pr_info("initialized (0x%p). heartbeat=%d sec (nowayout=%d, "
+                "force_addr=%s)\n",
+                tcobase, heartbeat, nowayout, addr_str);
 
         return 0;
 
 exit:
         iounmap(tcobase);
         release_mem_region(tcobase_phys, SP5100_WDT_MEM_MAP_SIZE);
+        if (resbase_phys)
+                release_resource(&wdt_res);
         release_region(pm_iobase, SP5100_PM_IOPORTS_SIZE);
         return ret;
 }
@@ -422,6 +641,8 @@ static void sp5100_tco_cleanup(void)
         misc_deregister(&sp5100_tco_miscdev);
         iounmap(tcobase);
         release_mem_region(tcobase_phys, SP5100_WDT_MEM_MAP_SIZE);
+        if (resbase_phys)
+                release_resource(&wdt_res);
         release_region(pm_iobase, SP5100_PM_IOPORTS_SIZE);
 }
 
@@ -451,7 +672,7 @@ static int __init sp5100_tco_init_module(void)
 {
         int err;
 
-        pr_info("SP5100 TCO WatchDog Timer Driver v%s\n", TCO_VERSION);
+        pr_info("SP5100/SB800 TCO WatchDog Timer Driver v%s\n", TCO_VERSION);
 
         err = platform_driver_register(&sp5100_tco_driver);
         if (err)
@@ -475,13 +696,13 @@ static void __exit sp5100_tco_cleanup_module(void)
 {
         platform_device_unregister(sp5100_tco_platform_device);
         platform_driver_unregister(&sp5100_tco_driver);
-        pr_info("SP5100 TCO Watchdog Module Unloaded\n");
+        pr_info("SP5100/SB800 TCO Watchdog Module Unloaded\n");
 }
 
 module_init(sp5100_tco_init_module);
 module_exit(sp5100_tco_cleanup_module);
 
 MODULE_AUTHOR("Priyanka Gupta");
-MODULE_DESCRIPTION("TCO timer driver for SP5100 chipset");
+MODULE_DESCRIPTION("TCO timer driver for SP5100/SB800 chipset");
 MODULE_LICENSE("GPL");
 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
diff --git a/drivers/watchdog/sp5100_tco.h b/drivers/watchdog/sp5100_tco.h
index a5a16cc90a34..71594a0c14b7 100644
--- a/drivers/watchdog/sp5100_tco.h
+++ b/drivers/watchdog/sp5100_tco.h
@@ -9,33 +9,57 @@
 /*
  * Some address definitions for the Watchdog
  */
-
 #define SP5100_WDT_MEM_MAP_SIZE         0x08
 #define SP5100_WDT_CONTROL(base)        ((base) + 0x00) /* Watchdog Control */
 #define SP5100_WDT_COUNT(base)          ((base) + 0x04) /* Watchdog Count */
 
-#define SP5100_WDT_START_STOP_BIT       1
+#define SP5100_WDT_START_STOP_BIT       (1 << 0)
 #define SP5100_WDT_TRIGGER_BIT          (1 << 7)
 
-#define SP5100_PCI_WATCHDOG_MISC_REG    0x41
-#define SP5100_PCI_WATCHDOG_DECODE_EN   (1 << 3)
-
 #define SP5100_PM_IOPORTS_SIZE          0x02
 
-/* These two IO registers are hardcoded and there doesn't seem to be a way to
+/*
+ * These two IO registers are hardcoded and there doesn't seem to be a way to
  * read them from a register.
  */
+
+/*  For SP5100/SB7x0 chipset */
 #define SP5100_IO_PM_INDEX_REG          0xCD6
 #define SP5100_IO_PM_DATA_REG           0xCD7
 
+#define SP5100_SB_RESOURCE_MMIO_BASE    0x9C
+
 #define SP5100_PM_WATCHDOG_CONTROL      0x69
-#define SP5100_PM_WATCHDOG_BASE0        0x6C
-#define SP5100_PM_WATCHDOG_BASE1        0x6D
-#define SP5100_PM_WATCHDOG_BASE2        0x6E
-#define SP5100_PM_WATCHDOG_BASE3        0x6F
+#define SP5100_PM_WATCHDOG_BASE         0x6C
 
 #define SP5100_PM_WATCHDOG_FIRED        (1 << 1)
 #define SP5100_PM_WATCHDOG_ACTION_RESET (1 << 2)
 
-#define SP5100_PM_WATCHDOG_DISABLE      1
+#define SP5100_PCI_WATCHDOG_MISC_REG    0x41
+#define SP5100_PCI_WATCHDOG_DECODE_EN   (1 << 3)
+
+#define SP5100_PM_WATCHDOG_DISABLE      (1 << 0)
 #define SP5100_PM_WATCHDOG_SECOND_RES   (3 << 1)
+
+#define SP5100_DEVNAME                  "SP5100 TCO"
+
+
+/*  For SB8x0(or later) chipset */
+#define SB800_IO_PM_INDEX_REG           0xCD6
+#define SB800_IO_PM_DATA_REG            0xCD7
+
+#define SB800_PM_ACPI_MMIO_EN           0x24
+#define SB800_PM_WATCHDOG_CONTROL       0x48
+#define SB800_PM_WATCHDOG_BASE          0x48
+#define SB800_PM_WATCHDOG_CONFIG        0x4C
+
+#define SB800_PCI_WATCHDOG_DECODE_EN    (1 << 0)
+#define SB800_PM_WATCHDOG_DISABLE       (1 << 2)
+#define SB800_PM_WATCHDOG_SECOND_RES    (3 << 0)
+#define SB800_ACPI_MMIO_DECODE_EN       (1 << 0)
+#define SB800_ACPI_MMIO_SEL             (1 << 2)
+
+
+#define SB800_PM_WDT_MMIO_OFFSET        0xB00
+
+#define SB800_DEVNAME                   "SB800 TCO"