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| author | Serge Semin <Sergey.Semin@baikalelectronics.ru> | 2022-06-24 16:34:19 +0200 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2022-07-06 02:00:52 +0200 |
| commit | bbc7c4de33e4cf2904f4bf562631b513a4df40bb (patch) | |
| tree | b9ded71ff92c29d10f488b3a18b8e28cddf3cdcd /drivers/pci/controller/dwc/pcie-designware.c | |
| parent | PCI: dwc: Add newlines to log messages (diff) | |
| download | linux-bbc7c4de33e4cf2904f4bf562631b513a4df40bb.tar.xz linux-bbc7c4de33e4cf2904f4bf562631b513a4df40bb.zip | |
PCI: dwc: Simplify unrolled iATU detection
The unrolled version of the internal ATU has been available since the DWC
PCIe v4.80a IP core, but it may not be enabled. Per [1], if unrolled ATU
is enabled, the PCIE_ATU_VIEWPORT does not exist and reads as 0xffffffff;
while if unrolled ATU is disabled, PCIE_ATU_VIEWPORT will contain some
zeros.
Simplify dw_pcie_iatu_unroll_enabled() by checking the value of
PCIE_ATU_VIEWPORT.
[1] DesignWare Cores, PCI Express Controller, Register Desciptions,
v.4.90a, December 2016, p.855
[bhelgaas: commit log]
Link: https://lore.kernel.org/r/20220624143428.8334-10-Sergey.Semin@baikalelectronics.ru
Tested-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Diffstat (limited to 'drivers/pci/controller/dwc/pcie-designware.c')
| -rw-r--r-- | drivers/pci/controller/dwc/pcie-designware.c | 11 |
1 files changed, 5 insertions, 6 deletions
diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c index ac966ed28c5b..e5c30695f664 100644 --- a/drivers/pci/controller/dwc/pcie-designware.c +++ b/drivers/pci/controller/dwc/pcie-designware.c @@ -600,15 +600,15 @@ static void dw_pcie_link_set_max_speed(struct dw_pcie *pci, u32 link_gen) } -static u8 dw_pcie_iatu_unroll_enabled(struct dw_pcie *pci) +static bool dw_pcie_iatu_unroll_enabled(struct dw_pcie *pci) { u32 val; val = dw_pcie_readl_dbi(pci, PCIE_ATU_VIEWPORT); if (val == 0xffffffff) - return 1; + return true; - return 0; + return false; } static void dw_pcie_iatu_detect_regions_unroll(struct dw_pcie *pci) @@ -680,9 +680,8 @@ void dw_pcie_iatu_detect(struct dw_pcie *pci) struct device *dev = pci->dev; struct platform_device *pdev = to_platform_device(dev); - if (pci->version >= 0x480A || (!pci->version && - dw_pcie_iatu_unroll_enabled(pci))) { - pci->iatu_unroll_enabled = true; + pci->iatu_unroll_enabled = dw_pcie_iatu_unroll_enabled(pci); + if (pci->iatu_unroll_enabled) { if (!pci->atu_base) { struct resource *res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "atu"); |