[PATCH 3/5] watchdog: atom-quark: Convert to direct PIO accesses

[Jan Kiszka]

From: Jan Kiszka <jan.k...@siemens.com>

Avoid the EFI_PCI_IO_PASS_THROUGH_BAR trick and rather access related
resources directly. Allows to drop a lot of error handling as well.

Signed-off-by: Jan Kiszka <jan.k...@siemens.com>
---
drivers/watchdog/atom-quark.c | 73 +++++++----------------------------
1 file changed, 13 insertions(+), 60 deletions(-)

diff --git a/drivers/watchdog/atom-quark.c b/drivers/watchdog/atom-quark.c
index e3a5495..c25406a 100644
--- a/drivers/watchdog/atom-quark.c
+++ b/drivers/watchdog/atom-quark.c
@@ -15,6 +15,7 @@
#include <efi.h>
#include <efilib.h>
#include <pci/header.h>
+#include <sys/io.h>

#define PCI_DEVICE_ID_INTEL_ITC 0x8186
#define PCI_DEVICE_ID_INTEL_CENTERTON 0x0c60
@@ -33,58 +34,29 @@
# define LOCK_WDT_LOCK (1 << 0)
# define LOCK_WDT_ENABLE (1 << 1)

-static EFI_STATUS unlock_timer_regs(EFI_PCI_IO *pci_io, UINT32 wdt_base)
+static void unlock_timer_regs(UINT32 wdt_base)
{
- EFI_STATUS status;
- UINT32 value;
-
- value = 0x80;
- status = uefi_call_wrapper(pci_io->Io.Write, 6, pci_io,
- EfiPciIoWidthUint8,
- EFI_PCI_IO_PASS_THROUGH_BAR,
- wdt_base + RELOAD0_REG, 1, &value);
- if (EFI_ERROR(status)) {
- return status;
- }
-
- value = 0x86;
- return uefi_call_wrapper(pci_io->Io.Write, 6, pci_io,
- EfiPciIoWidthUint8,
- EFI_PCI_IO_PASS_THROUGH_BAR,
- wdt_base + RELOAD0_REG, 1, &value);
+ outb(0x80, wdt_base + RELOAD0_REG);
+ outb(0x86, wdt_base + RELOAD0_REG);
}

-static EFI_STATUS write_timer_regs(EFI_PCI_IO *pci_io, UINT32 wdt_base,
- UINT32 timer, UINT32 value)
+static void write_timer_regs(UINT32 wdt_base, UINT32 timer, UINT32 value)
{
for (unsigned int n = 0; n < 3; n++) {
- EFI_STATUS status;
-
- status = unlock_timer_regs(pci_io, wdt_base);
- if (EFI_ERROR(status)) {
- return status;
- }
+ unlock_timer_regs(wdt_base);

- status = uefi_call_wrapper(pci_io->Io.Write, 6, pci_io,
- EfiPciIoWidthUint8,
- EFI_PCI_IO_PASS_THROUGH_BAR,
- wdt_base + timer, 1, &value);
- if (EFI_ERROR(status)) {
- return status;
- }
+ outb((UINT8)value, wdt_base + timer);

value >>= 8;
timer++;
}
-
- return EFI_SUCCESS;
}

static EFI_STATUS __attribute__((constructor))
init(EFI_PCI_IO *pci_io, UINT16 pci_vendor_id, UINT16 pci_device_id,
UINTN timeout)
{
- UINT32 wdt_base, value;
+ UINT32 wdt_base;
EFI_STATUS status;

if (!pci_io || pci_vendor_id != PCI_VENDOR_ID_INTEL ||
@@ -109,32 +81,13 @@ init(EFI_PCI_IO *pci_io, UINT16 pci_vendor_id, UINT16 pci_device_id,

Print(L"Detected Intel Atom/Quark watchdog\n");

- value = ((timeout * 1000000000ULL) >> 15) / 30;
- status = write_timer_regs(pci_io, wdt_base, TIMER1_REG, value);
- if (EFI_ERROR(status)) {
- return status;
- }
-
- value = 0;
- status = write_timer_regs(pci_io, wdt_base, TIMER2_REG, value);
- if (EFI_ERROR(status)) {
- return status;
- }
+ write_timer_regs(wdt_base, TIMER1_REG,
+ ((timeout * 1000000000ULL) >> 15) / 30);
+ write_timer_regs(wdt_base, TIMER2_REG, 0);

- value = CONFIG_RESET_ENABLE;
- status = uefi_call_wrapper(pci_io->Io.Write, 6, pci_io,
- EfiPciIoWidthUint8,
- EFI_PCI_IO_PASS_THROUGH_BAR,
- wdt_base + CONFIG_REG, 1, &value);
- if (EFI_ERROR(status)) {
- return status;
- }
+ outb(CONFIG_RESET_ENABLE, wdt_base + CONFIG_REG);

- value = LOCK_WDT_ENABLE | LOCK_WDT_LOCK;
- status = uefi_call_wrapper(pci_io->Io.Write, 6, pci_io,
- EfiPciIoWidthUint8,
- EFI_PCI_IO_PASS_THROUGH_BAR,
- wdt_base + LOCK_REG, 1, &value);
+ outb(LOCK_WDT_ENABLE | LOCK_WDT_LOCK, wdt_base + LOCK_REG);

return status;
}
--
2.26.2