[PATCH 8/9] pci: mvebu: add PCI Express root complex capability block
Russell King
rmk+kernel at arm.linux.org.uk
Sat Oct 3 11:13:33 PDT 2015
Add a PCI Express root complex capability block so the PCI layer
identifies the bridge as a PCI Express device.
We expose this as a version 1 PCIe capability block, with slot support.
We disable the clock power management capability as this depends on
boards wiring the CLKREQ# signal.
Signed-off-by: Russell King <rmk+kernel at arm.linux.org.uk>
---
drivers/pci/host/pci-mvebu.c | 137 +++++++++++++++++++++++++++++++++++++++++--
1 file changed, 133 insertions(+), 4 deletions(-)
diff --git a/drivers/pci/host/pci-mvebu.c b/drivers/pci/host/pci-mvebu.c
index 97208233d901..6310f2a84cfd 100644
--- a/drivers/pci/host/pci-mvebu.c
+++ b/drivers/pci/host/pci-mvebu.c
@@ -30,6 +30,7 @@
#define PCIE_DEV_REV_OFF 0x0008
#define PCIE_BAR_LO_OFF(n) (0x0010 + ((n) << 3))
#define PCIE_BAR_HI_OFF(n) (0x0014 + ((n) << 3))
+#define PCIE_CAP_PCIEXP 0x0060
#define PCIE_HEADER_LOG_4_OFF 0x0128
#define PCIE_BAR_CTRL_OFF(n) (0x1804 + (((n) - 1) * 4))
#define PCIE_WIN04_CTRL_OFF(n) (0x1820 + ((n) << 4))
@@ -57,14 +58,35 @@
#define PCIE_STAT_BUS 0xff00
#define PCIE_STAT_DEV 0x1f0000
#define PCIE_STAT_LINK_DOWN BIT(0)
+#define PCIE_RC_RTSTA 0x1a14
#define PCIE_DEBUG_CTRL 0x1a60
#define PCIE_DEBUG_SOFT_RESET BIT(20)
+enum {
+ PCISWCAP = PCI_BRIDGE_CONTROL + 2,
+ PCISWCAP_EXP_LIST_ID = PCISWCAP + PCI_CAP_LIST_ID,
+ PCISWCAP_EXP_DEVCAP = PCISWCAP + PCI_EXP_DEVCAP,
+ PCISWCAP_EXP_DEVCTL = PCISWCAP + PCI_EXP_DEVCTL,
+ PCISWCAP_EXP_LNKCAP = PCISWCAP + PCI_EXP_LNKCAP,
+ PCISWCAP_EXP_LNKCTL = PCISWCAP + PCI_EXP_LNKCTL,
+ PCISWCAP_EXP_SLTCAP = PCISWCAP + PCI_EXP_SLTCAP,
+ PCISWCAP_EXP_SLTCTL = PCISWCAP + PCI_EXP_SLTCTL,
+ PCISWCAP_EXP_RTCTL = PCISWCAP + PCI_EXP_RTCTL,
+ PCISWCAP_EXP_RTSTA = PCISWCAP + PCI_EXP_RTSTA,
+ PCISWCAP_EXP_DEVCAP2 = PCISWCAP + PCI_EXP_DEVCAP2,
+ PCISWCAP_EXP_DEVCTL2 = PCISWCAP + PCI_EXP_DEVCTL2,
+ PCISWCAP_EXP_LNKCAP2 = PCISWCAP + PCI_EXP_LNKCAP2,
+ PCISWCAP_EXP_LNKCTL2 = PCISWCAP + PCI_EXP_LNKCTL2,
+ PCISWCAP_EXP_SLTCAP2 = PCISWCAP + PCI_EXP_SLTCAP2,
+ PCISWCAP_EXP_SLTCTL2 = PCISWCAP + PCI_EXP_SLTCTL2,
+};
+
/* PCI configuration space of a PCI-to-PCI bridge */
struct mvebu_sw_pci_bridge {
u16 vendor;
u16 device;
u16 command;
+ u16 status;
u16 class;
u8 interface;
u8 revision;
@@ -84,13 +106,15 @@ struct mvebu_sw_pci_bridge {
u16 memlimit;
u16 iobaseupper;
u16 iolimitupper;
- u8 cappointer;
- u8 reserved1;
- u16 reserved2;
u32 romaddr;
u8 intline;
u8 intpin;
u16 bridgectrl;
+
+ /* PCI express capability */
+ u32 pcie_sltcap;
+ u16 pcie_devctl;
+ u16 pcie_rtctl;
};
struct mvebu_pcie_port;
@@ -451,6 +475,9 @@ static void mvebu_sw_pci_bridge_init(struct mvebu_pcie_port *port)
/* We support 32 bits I/O addressing */
bridge->iobase = PCI_IO_RANGE_TYPE_32;
bridge->iolimit = PCI_IO_RANGE_TYPE_32;
+
+ /* Add capabilities */
+ bridge->status = PCI_STATUS_CAP_LIST;
}
/*
@@ -468,7 +495,7 @@ static int mvebu_sw_pci_bridge_read(struct mvebu_pcie_port *port,
break;
case PCI_COMMAND:
- *value = bridge->command;
+ *value = bridge->command | bridge->status << 16;
break;
case PCI_CLASS_REVISION:
@@ -513,6 +540,10 @@ static int mvebu_sw_pci_bridge_read(struct mvebu_pcie_port *port,
*value = (bridge->iolimitupper << 16 | bridge->iobaseupper);
break;
+ case PCI_CAPABILITY_LIST:
+ *value = PCISWCAP;
+ break;
+
case PCI_ROM_ADDRESS1:
*value = 0;
break;
@@ -522,6 +553,59 @@ static int mvebu_sw_pci_bridge_read(struct mvebu_pcie_port *port,
*value = 0;
break;
+ case PCISWCAP_EXP_LIST_ID:
+ /* Set PCIe v2, root port, slot support */
+ *value = (PCI_EXP_TYPE_ROOT_PORT << 4 | 2 |
+ PCI_EXP_FLAGS_SLOT) << 16 | PCI_CAP_ID_EXP;
+ break;
+
+ case PCISWCAP_EXP_DEVCAP:
+ *value = mvebu_readl(port, PCIE_CAP_PCIEXP + PCI_EXP_DEVCAP);
+ break;
+
+ case PCISWCAP_EXP_DEVCTL:
+ *value = mvebu_readl(port, PCIE_CAP_PCIEXP + PCI_EXP_DEVCTL) &
+ ~(PCI_EXP_DEVCTL_URRE | PCI_EXP_DEVCTL_FERE |
+ PCI_EXP_DEVCTL_NFERE | PCI_EXP_DEVCTL_CERE);
+ *value |= bridge->pcie_devctl;
+ break;
+
+ case PCISWCAP_EXP_LNKCAP:
+ /*
+ * PCIe requires the clock power management capability to be
+ * hard-wired to zero for downstream ports
+ */
+ *value = mvebu_readl(port, PCIE_CAP_PCIEXP + PCI_EXP_LNKCAP) &
+ ~PCI_EXP_LNKCAP_CLKPM;
+ break;
+
+ case PCISWCAP_EXP_LNKCTL:
+ *value = mvebu_readl(port, PCIE_CAP_PCIEXP + PCI_EXP_LNKCTL);
+ break;
+
+ case PCISWCAP_EXP_SLTCAP:
+ *value = bridge->pcie_sltcap;
+ break;
+
+ case PCISWCAP_EXP_SLTCTL:
+ *value = PCI_EXP_SLTSTA_PDS << 16;
+ break;
+
+ case PCISWCAP_EXP_RTCTL:
+ *value = bridge->pcie_rtctl;
+ break;
+
+ case PCISWCAP_EXP_RTSTA:
+ *value = mvebu_readl(port, PCIE_RC_RTSTA);
+ break;
+
+ /* PCIe requires the v2 fields to be hard-wired to zero */
+ case PCISWCAP_EXP_DEVCAP2:
+ case PCISWCAP_EXP_DEVCTL2:
+ case PCISWCAP_EXP_LNKCAP2:
+ case PCISWCAP_EXP_LNKCTL2:
+ case PCISWCAP_EXP_SLTCAP2:
+ case PCISWCAP_EXP_SLTCTL2:
default:
/*
* PCI defines configuration read accesses to reserved or
@@ -614,6 +698,51 @@ static int mvebu_sw_pci_bridge_write(struct mvebu_pcie_port *port,
mvebu_pcie_set_local_bus_nr(port, bridge->secondary_bus);
break;
+ case PCISWCAP_EXP_DEVCTL:
+ /*
+ * Armada370 data says these bits must always
+ * be zero when in root complex mode.
+ */
+ value &= ~(PCI_EXP_DEVCTL_URRE | PCI_EXP_DEVCTL_FERE |
+ PCI_EXP_DEVCTL_NFERE | PCI_EXP_DEVCTL_CERE);
+
+ /*
+ * If the mask is 0xffff0000, then we only want to write
+ * the device control register, rather than clearing the
+ * RW1C bits in the device status register. Mask out the
+ * status register bits.
+ */
+ if (mask == 0xffff0000)
+ value &= 0xffff;
+
+ mvebu_writel(port, value, PCIE_CAP_PCIEXP + PCI_EXP_DEVCTL);
+ break;
+
+ case PCISWCAP_EXP_LNKCTL:
+ /*
+ * If we don't support CLKREQ, we must ensure that the
+ * CLKREQ enable bit always reads zero. Since we haven't
+ * had this capability, and it's dependent on board wiring,
+ * disable it for the time being.
+ */
+ value &= ~PCI_EXP_LNKCTL_CLKREQ_EN;
+
+ /*
+ * If the mask is 0xffff0000, then we only want to write
+ * the link control register, rather than clearing the
+ * RW1C bits in the link status register. Mask out the
+ * status register bits.
+ */
+ if (mask == 0xffff0000)
+ value &= 0xffff;
+
+ mvebu_writel(port, value, PCIE_CAP_PCIEXP + PCI_EXP_LNKCTL);
+ break;
+
+ case PCISWCAP_EXP_RTSTA:
+ mvebu_writel(port, value, PCIE_RC_RTSTA);
+ break;
+
default:
break;
}
--
2.1.0
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