diff options
| author | Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> | 2023-10-18 11:56:22 +0300 |
|---|---|---|
| committer | Krzysztof Wilczyński <kwilczynski@kernel.org> | 2023-10-20 15:12:56 +0300 |
| commit | 1896d17f916819b8b5d145b4feef77109e78c435 (patch) | |
| tree | 8653ef506eef23d9f79aa1fcdd87707ac4c79853 /drivers/pci/controller/dwc/pcie-designware.c | |
| parent | 7873b49b41b92edb3395bff9a528eaf89da5e41c (diff) | |
| download | linux-1896d17f916819b8b5d145b4feef77109e78c435.tar.xz | |
PCI: dwc: Add EDMA_UNROLL capability flag
Renesas R-Car Gen4 PCIe controllers have an unexpected register value in
the eDMA CTRL register.
So, add a new capability flag "EDMA_UNROLL" which would force the unrolled
eDMA mapping for the problematic device.
Suggested-by: Serge Semin <fancer.lancer@gmail.com>
Link: https://lore.kernel.org/linux-pci/20231018085631.1121289-7-yoshihiro.shimoda.uh@renesas.com
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Serge Semin <fancer.lancer@gmail.com>
Diffstat (limited to 'drivers/pci/controller/dwc/pcie-designware.c')
| -rw-r--r-- | drivers/pci/controller/dwc/pcie-designware.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c index 2b60d20dfdf5..1f900be94556 100644 --- a/drivers/pci/controller/dwc/pcie-designware.c +++ b/drivers/pci/controller/dwc/pcie-designware.c @@ -887,8 +887,14 @@ static int dw_pcie_edma_find_chip(struct dw_pcie *pci) * Indirect eDMA CSRs access has been completely removed since v5.40a * thus no space is now reserved for the eDMA channels viewport and * former DMA CTRL register is no longer fixed to FFs. + * + * Note that Renesas R-Car S4-8's PCIe controllers for unknown reason + * have zeros in the eDMA CTRL register even though the HW-manual + * explicitly states there must FFs if the unrolled mapping is enabled. + * For such cases the low-level drivers are supposed to manually + * activate the unrolled mapping to bypass the auto-detection procedure. */ - if (dw_pcie_ver_is_ge(pci, 540A)) + if (dw_pcie_ver_is_ge(pci, 540A) || dw_pcie_cap_is(pci, EDMA_UNROLL)) val = 0xFFFFFFFF; else val = dw_pcie_readl_dbi(pci, PCIE_DMA_VIEWPORT_BASE + PCIE_DMA_CTRL); |