diff options
| author | Shmuel Hazan <sh@tkos.co.il> | 2020-06-23 09:03:35 +0300 |
|---|---|---|
| committer | Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> | 2020-07-14 15:09:16 +0100 |
| commit | 216f8e95aacc8e9690d8e2286c472671b65f4128 (patch) | |
| tree | 2a85b53238ae205fba124ea3a30ed0f406266d19 /drivers/pci/controller/pci-mvebu.c | |
| parent | b3a9e3b9622ae10064826dccb4f7a52bd88c7407 (diff) | |
PCI: mvebu: Setup BAR0 in order to fix MSI
According to the Armada XP datasheet, section 10.2.6: "in order for
the device to do a write to the MSI doorbell address, it needs to write
to a register in the internal registers space".
As a result of the requirement above, without this patch, MSI won't
function and therefore some devices won't operate properly without
pci=nomsi.
This requirement was not present at the time of writing this driver
since the vendor u-boot always initializes all PCIe controllers
(incl. BAR0 initialization) and for some time, the vendor u-boot was
the only available bootloader for this driver's SoCs (e.g. A38x,A37x,
etc).
Tested on an Armada 385 board on mainline u-boot (2020.4), without
u-boot PCI initialization and the following PCIe devices:
- Wilocity Wil6200 rev 2 (wil6210)
- Qualcomm Atheros QCA6174 (ath10k_pci)
Both failed to get a response from the device after loading the
firmware and seem to operate properly with this patch.
Link: https://lore.kernel.org/r/20200623060334.108444-1-sh@tkos.co.il
Signed-off-by: Shmuel Hazan <sh@tkos.co.il>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Diffstat (limited to 'drivers/pci/controller/pci-mvebu.c')
| -rw-r--r-- | drivers/pci/controller/pci-mvebu.c | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/drivers/pci/controller/pci-mvebu.c b/drivers/pci/controller/pci-mvebu.c index 153a64676bc9..101c06602aa1 100644 --- a/drivers/pci/controller/pci-mvebu.c +++ b/drivers/pci/controller/pci-mvebu.c @@ -105,6 +105,7 @@ struct mvebu_pcie_port { struct mvebu_pcie_window memwin; struct mvebu_pcie_window iowin; u32 saved_pcie_stat; + struct resource regs; }; static inline void mvebu_writel(struct mvebu_pcie_port *port, u32 val, u32 reg) @@ -149,7 +150,9 @@ static void mvebu_pcie_set_local_dev_nr(struct mvebu_pcie_port *port, int nr) /* * Setup PCIE BARs and Address Decode Wins: - * BAR[0,2] -> disabled, BAR[1] -> covers all DRAM banks + * BAR[0] -> internal registers (needed for MSI) + * BAR[1] -> covers all DRAM banks + * BAR[2] -> Disabled * WIN[0-3] -> DRAM bank[0-3] */ static void mvebu_pcie_setup_wins(struct mvebu_pcie_port *port) @@ -203,6 +206,12 @@ static void mvebu_pcie_setup_wins(struct mvebu_pcie_port *port) mvebu_writel(port, 0, PCIE_BAR_HI_OFF(1)); mvebu_writel(port, ((size - 1) & 0xffff0000) | 1, PCIE_BAR_CTRL_OFF(1)); + + /* + * Point BAR[0] to the device's internal registers. + */ + mvebu_writel(port, round_down(port->regs.start, SZ_1M), PCIE_BAR_LO_OFF(0)); + mvebu_writel(port, 0, PCIE_BAR_HI_OFF(0)); } static void mvebu_pcie_setup_hw(struct mvebu_pcie_port *port) @@ -708,14 +717,13 @@ static void __iomem *mvebu_pcie_map_registers(struct platform_device *pdev, struct device_node *np, struct mvebu_pcie_port *port) { - struct resource regs; int ret = 0; - ret = of_address_to_resource(np, 0, ®s); + ret = of_address_to_resource(np, 0, &port->regs); if (ret) return (void __iomem *)ERR_PTR(ret); - return devm_ioremap_resource(&pdev->dev, ®s); + return devm_ioremap_resource(&pdev->dev, &port->regs); } #define DT_FLAGS_TO_TYPE(flags) (((flags) >> 24) & 0x03) |