[PATCH v2 1/4] x86: spi: Add a way to access the SPI mapping via registers

[Simon Glass]

At present the PCI BDF (bus/device/function) is needed to access the SPI
mapping, since the registers are at BAR0. This doesn't work when PCI
auto-config has not been done yet, since BARs are unassigned.

Add another way to find the mapping, using the MMIO base, if the caller
knows this.

Also add a missing function comment.

Signed-off-by: Simon Glass <s...@chromium.org>
---

Changes in v2: None

 arch/x86/cpu/intel_common/fast_spi.c | 19 ++++++++++++++-----
 arch/x86/include/asm/fast_spi.h      | 19 +++++++++++++++++++
 2 files changed, 33 insertions(+), 5 deletions(-)

diff --git a/arch/x86/cpu/intel_common/fast_spi.c 
b/arch/x86/cpu/intel_common/fast_spi.c
index a6e3d0a5bf..5d3944dee2 100644
--- a/arch/x86/cpu/intel_common/fast_spi.c
+++ b/arch/x86/cpu/intel_common/fast_spi.c
@@ -31,21 +31,30 @@ static ulong fast_spi_get_bios_region(struct fast_spi_regs 
*regs,
        return bios_start;
 }
 
+int fast_spi_get_bios_mmap_regs(struct fast_spi_regs *regs, ulong *map_basep,
+                               uint *map_sizep, uint *offsetp)
+{
+       ulong base;
+
+       base = fast_spi_get_bios_region(regs, map_sizep);
+       *map_basep = (u32)-*map_sizep - base;
+       *offsetp = base;
+
+       return 0;
+}
+
 int fast_spi_get_bios_mmap(pci_dev_t pdev, ulong *map_basep, uint *map_sizep,
                           uint *offsetp)
 {
        struct fast_spi_regs *regs;
-       ulong bar, base, mmio_base;
+       ulong bar, mmio_base;
 
        /* Special case to find mapping without probing the device */
        pci_x86_read_config(pdev, PCI_BASE_ADDRESS_0, &bar, PCI_SIZE_32);
        mmio_base = bar & PCI_BASE_ADDRESS_MEM_MASK;
        regs = (struct fast_spi_regs *)mmio_base;
-       base = fast_spi_get_bios_region(regs, map_sizep);
-       *map_basep = (u32)-*map_sizep - base;
-       *offsetp = base;
 
-       return 0;
+       return fast_spi_get_bios_mmap_regs(regs, map_basep, map_sizep, offsetp);
 }
 
 int fast_spi_early_init(pci_dev_t pdev, ulong mmio_base)
diff --git a/arch/x86/include/asm/fast_spi.h b/arch/x86/include/asm/fast_spi.h
index 47c1da80d7..7a81d4f05c 100644
--- a/arch/x86/include/asm/fast_spi.h
+++ b/arch/x86/include/asm/fast_spi.h
@@ -64,6 +64,25 @@ check_member(fast_spi_regs, ptdata, 0xd0);
 int fast_spi_get_bios_mmap(pci_dev_t pdev, ulong *map_basep, uint *map_sizep,
                           uint *offsetp);
 
+/**
+ * fast_spi_get_bios_mmap_regs() - Get memory map for SPI flash given regs
+ *
+ * @regs:      SPI registers to use
+ * @map_basep: Returns base memory address for mapped SPI
+ * @map_sizep: Returns size of mapped SPI
+ * @offsetp:   Returns start offset of SPI flash where the map works
+ *     correctly (offsets before this are not visible)
+ * @return 0 (always)
+ */
+int fast_spi_get_bios_mmap_regs(struct fast_spi_regs *regs, ulong *map_basep,
+                               uint *map_sizep, uint *offsetp);
+
+/**
+ * fast_spi_early_init() - Set up a BAR to use SPI early in U-Boot
+ *
+ * @pdev:      PCI device to use (this is the Fast SPI device)
+ * @mmio_base: MMIO base to use to access registers
+ */
 int fast_spi_early_init(pci_dev_t pdev, ulong mmio_base);
 
 #endif /* ASM_FAST_SPI_H */
-- 
2.27.0.rc0.183.gde8f92d652-goog