Watchdog: sp5100_tco: Refactor MMIO base address initialization

Combine MMIO base address and alternate base address detection. Combine
based on layout type. This will simplify the function by eliminating
a switch case.

Move existing request/release code into functions. This currently only
supports port I/O request/release. The move into a separate function
will make it ready for adding MMIO region support.

Co-developed-by: Robert Richter <rrichter@amd.com>
Signed-off-by: Robert Richter <rrichter@amd.com>
Signed-off-by: Terry Bowman <terry.bowman@amd.com>
Tested-by: Jean Delvare <jdelvare@suse.de>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20220202153525.1693378-3-terry.bowman@amd.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

diff --git a/drivers/watchdog/sp5100_tco.c b/drivers/watchdog/sp5100_tco.c
index b365bbc..8db7504 100644 (file)
--- a/drivers/watchdog/sp5100_tco.c
+++ b/drivers/watchdog/sp5100_tco.c
@@ -223,6 +223,55 @@ static u32 sp5100_tco_read_pm_reg32(u8 index)
        return val;
 }
 
+static u32 sp5100_tco_request_region(struct device *dev,
+                                    u32 mmio_addr,
+                                    const char *dev_name)
+{
+       if (!devm_request_mem_region(dev, mmio_addr, SP5100_WDT_MEM_MAP_SIZE,
+                                    dev_name)) {
+               dev_dbg(dev, "MMIO address 0x%08x already in use\n", mmio_addr);
+               return 0;
+       }
+
+       return mmio_addr;
+}
+
+static u32 sp5100_tco_prepare_base(struct sp5100_tco *tco,
+                                  u32 mmio_addr,
+                                  u32 alt_mmio_addr,
+                                  const char *dev_name)
+{
+       struct device *dev = tco->wdd.parent;
+
+       dev_dbg(dev, "Got 0x%08x from SBResource_MMIO register\n", mmio_addr);
+
+       if (!mmio_addr && !alt_mmio_addr)
+               return -ENODEV;
+
+       /* Check for MMIO address and alternate MMIO address conflicts */
+       if (mmio_addr)
+               mmio_addr = sp5100_tco_request_region(dev, mmio_addr, dev_name);
+
+       if (!mmio_addr && alt_mmio_addr)
+               mmio_addr = sp5100_tco_request_region(dev, alt_mmio_addr, dev_name);
+
+       if (!mmio_addr) {
+               dev_err(dev, "Failed to reserve MMIO or alternate MMIO region\n");
+               return -EBUSY;
+       }
+
+       tco->tcobase = devm_ioremap(dev, mmio_addr, SP5100_WDT_MEM_MAP_SIZE);
+       if (!tco->tcobase) {
+               dev_err(dev, "MMIO address 0x%08x failed mapping\n", mmio_addr);
+               devm_release_mem_region(dev, mmio_addr, SP5100_WDT_MEM_MAP_SIZE);
+               return -ENOMEM;
+       }
+
+       dev_info(dev, "Using 0x%08x for watchdog MMIO address\n", mmio_addr);
+
+       return 0;
+}
+
 static int sp5100_tco_timer_init(struct sp5100_tco *tco)
 {
        struct watchdog_device *wdd = &tco->wdd;
@@ -264,6 +313,7 @@ static int sp5100_tco_setupdevice(struct device *dev,
        struct sp5100_tco *tco = watchdog_get_drvdata(wdd);
        const char *dev_name;
        u32 mmio_addr = 0, val;
+       u32 alt_mmio_addr = 0;
        int ret;
 
        /* Request the IO ports used by this driver */
@@ -282,11 +332,32 @@ static int sp5100_tco_setupdevice(struct device *dev,
                dev_name = SP5100_DEVNAME;
                mmio_addr = sp5100_tco_read_pm_reg32(SP5100_PM_WATCHDOG_BASE) &
                                                                0xfffffff8;
+
+               /*
+                * Secondly, find the watchdog timer MMIO address
+                * from SBResource_MMIO register.
+                */
+
+               /* Read SBResource_MMIO from PCI config(PCI_Reg: 9Ch) */
+               pci_read_config_dword(sp5100_tco_pci,
+                                     SP5100_SB_RESOURCE_MMIO_BASE,
+                                     &val);
+
+               /* Verify MMIO is enabled and using bar0 */
+               if ((val & SB800_ACPI_MMIO_MASK) == SB800_ACPI_MMIO_DECODE_EN)
+                       alt_mmio_addr = (val & ~0xfff) + SB800_PM_WDT_MMIO_OFFSET;
                break;
        case sb800:
                dev_name = SB800_DEVNAME;
                mmio_addr = sp5100_tco_read_pm_reg32(SB800_PM_WATCHDOG_BASE) &
                                                                0xfffffff8;
+
+               /* Read SBResource_MMIO from AcpiMmioEn(PM_Reg: 24h) */
+               val = sp5100_tco_read_pm_reg32(SB800_PM_ACPI_MMIO_EN);
+
+               /* Verify MMIO is enabled and using bar0 */
+               if ((val & SB800_ACPI_MMIO_MASK) == SB800_ACPI_MMIO_DECODE_EN)
+                       alt_mmio_addr = (val & ~0xfff) + SB800_PM_WDT_MMIO_OFFSET;
                break;
        case efch:
                dev_name = SB800_DEVNAME;
@@ -305,87 +376,23 @@ static int sp5100_tco_setupdevice(struct device *dev,
                val = sp5100_tco_read_pm_reg8(EFCH_PM_DECODEEN);
                if (val & EFCH_PM_DECODEEN_WDT_TMREN)
                        mmio_addr = EFCH_PM_WDT_ADDR;
+
+               val = sp5100_tco_read_pm_reg8(EFCH_PM_ISACONTROL);
+               if (val & EFCH_PM_ISACONTROL_MMIOEN)
+                       alt_mmio_addr = EFCH_PM_ACPI_MMIO_ADDR +
+                               EFCH_PM_ACPI_MMIO_WDT_OFFSET;
                break;
        default:
                return -ENODEV;
        }
 
-       /* Check MMIO address conflict */
-       if (!mmio_addr ||
-           !devm_request_mem_region(dev, mmio_addr, SP5100_WDT_MEM_MAP_SIZE,
-                                    dev_name)) {
-               if (mmio_addr)
-                       dev_dbg(dev, "MMIO address 0x%08x already in use\n",
-                               mmio_addr);
-               switch (tco->tco_reg_layout) {
-               case sp5100:
-                       /*
-                        * Secondly, Find the watchdog timer MMIO address
-                        * from SBResource_MMIO register.
-                        */
-                       /* Read SBResource_MMIO from PCI config(PCI_Reg: 9Ch) */
-                       pci_read_config_dword(sp5100_tco_pci,
-                                             SP5100_SB_RESOURCE_MMIO_BASE,
-                                             &mmio_addr);
-                       if ((mmio_addr & (SB800_ACPI_MMIO_DECODE_EN |
-                                         SB800_ACPI_MMIO_SEL)) !=
-                                                 SB800_ACPI_MMIO_DECODE_EN) {
-                               ret = -ENODEV;
-                               goto unreg_region;
-                       }
-                       mmio_addr &= ~0xFFF;
-                       mmio_addr += SB800_PM_WDT_MMIO_OFFSET;
-                       break;
-               case sb800:
-                       /* Read SBResource_MMIO from AcpiMmioEn(PM_Reg: 24h) */
-                       mmio_addr =
-                               sp5100_tco_read_pm_reg32(SB800_PM_ACPI_MMIO_EN);
-                       if ((mmio_addr & (SB800_ACPI_MMIO_DECODE_EN |
-                                         SB800_ACPI_MMIO_SEL)) !=
-                                                 SB800_ACPI_MMIO_DECODE_EN) {
-                               ret = -ENODEV;
-                               goto unreg_region;
-                       }
-                       mmio_addr &= ~0xFFF;
-                       mmio_addr += SB800_PM_WDT_MMIO_OFFSET;
-                       break;
-               case efch:
-                       val = sp5100_tco_read_pm_reg8(EFCH_PM_ISACONTROL);
-                       if (!(val & EFCH_PM_ISACONTROL_MMIOEN)) {
-                               ret = -ENODEV;
-                               goto unreg_region;
-                       }
-                       mmio_addr = EFCH_PM_ACPI_MMIO_ADDR +
-                                   EFCH_PM_ACPI_MMIO_WDT_OFFSET;
-                       break;
-               }
-               dev_dbg(dev, "Got 0x%08x from SBResource_MMIO register\n",
-                       mmio_addr);
-               if (!devm_request_mem_region(dev, mmio_addr,
-                                            SP5100_WDT_MEM_MAP_SIZE,
-                                            dev_name)) {
-                       dev_dbg(dev, "MMIO address 0x%08x already in use\n",
-                               mmio_addr);
-                       ret = -EBUSY;
-                       goto unreg_region;
-               }
-       }
-
-       tco->tcobase = devm_ioremap(dev, mmio_addr, SP5100_WDT_MEM_MAP_SIZE);
-       if (!tco->tcobase) {
-               dev_err(dev, "failed to get tcobase address\n");
-               ret = -ENOMEM;
-               goto unreg_region;
+       ret = sp5100_tco_prepare_base(tco, mmio_addr, alt_mmio_addr, dev_name);
+       if (!ret) {
+               /* Setup the watchdog timer */
+               tco_timer_enable(tco);
+               ret = sp5100_tco_timer_init(tco);
        }
 
-       dev_info(dev, "Using 0x%08x for watchdog MMIO address\n", mmio_addr);
-
-       /* Setup the watchdog timer */
-       tco_timer_enable(tco);
-
-       ret = sp5100_tco_timer_init(tco);
-
-unreg_region:
        release_region(SP5100_IO_PM_INDEX_REG, SP5100_PM_IOPORTS_SIZE);
        return ret;
 }

diff --git a/drivers/watchdog/sp5100_tco.h b/drivers/watchdog/sp5100_tco.h
index adf015a..daee872 100644 (file)
--- a/drivers/watchdog/sp5100_tco.h
+++ b/drivers/watchdog/sp5100_tco.h
@@ -58,6 +58,7 @@
 #define SB800_PM_WATCHDOG_SECOND_RES   GENMASK(1, 0)
 #define SB800_ACPI_MMIO_DECODE_EN      BIT(0)
 #define SB800_ACPI_MMIO_SEL            BIT(1)
+#define SB800_ACPI_MMIO_MASK           GENMASK(1, 0)
 
 #define SB800_PM_WDT_MMIO_OFFSET       0xB00