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>

1 files changed, 35 insertions, 11 deletions

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"