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PCI: dwc: Add EDMA_UNROLL capability flag

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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>
This commit is contained in:
Yoshihiro Shimoda 2023-10-18 17:56:22 +09:00 committed by Krzysztof Wilczyński
parent 7873b49b41
commit 1896d17f91
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GPG Key ID: 7C64768D3DE334E7
2 changed files with 10 additions and 3 deletions
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8
drivers/pci/controller/dwc/pcie-designware.c
View File

@ -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);

5
drivers/pci/controller/dwc/pcie-designware.h
View File

@ -51,8 +51,9 @@
/* DWC PCIe controller capabilities */
#define DW_PCIE_CAP_REQ_RES 0
#define DW_PCIE_CAP_IATU_UNROLL 1
#define DW_PCIE_CAP_CDM_CHECK 2
#define DW_PCIE_CAP_EDMA_UNROLL 1
#define DW_PCIE_CAP_IATU_UNROLL 2
#define DW_PCIE_CAP_CDM_CHECK 3
#define dw_pcie_cap_is(_pci, _cap) \
test_bit(DW_PCIE_CAP_ ## _cap, &(_pci)->caps)