Add PCIe legacy interrupt INTx support to the iProc PCIe driver by
modeling it with its own IRQ domain. All 4 interrupts INTA, INTB, INTC,
INTD share the same interrupt line connected to the GIC in the system,
while the status of each INTx can be obtained through the INTX CSR
register
Signed-off-by: Ray Jui <ray.jui@xxxxxxxxxxxx>
---
drivers/pci/host/pcie-iproc-platform.c | 2 +
drivers/pci/host/pcie-iproc.c | 95
+++++++++++++++++++++++++++++++++-
drivers/pci/host/pcie-iproc.h | 6 +++
3 files changed, 101 insertions(+), 2 deletions(-)
diff --git a/drivers/pci/host/pcie-iproc-platform.c
b/drivers/pci/host/pcie-iproc-platform.c
index e764a2a..7a51e6c 100644
--- a/drivers/pci/host/pcie-iproc-platform.c
+++ b/drivers/pci/host/pcie-iproc-platform.c
@@ -70,6 +70,8 @@ static int iproc_pcie_pltfm_probe(struct
platform_device *pdev)
}
pcie->base_addr = reg.start;
+ pcie->irq = platform_get_irq(pdev, 0);
+
if (of_property_read_bool(np, "brcm,pcie-ob")) {
u32 val;
diff --git a/drivers/pci/host/pcie-iproc.c
b/drivers/pci/host/pcie-iproc.c
index 14f374d..0bd2c14 100644
--- a/drivers/pci/host/pcie-iproc.c
+++ b/drivers/pci/host/pcie-iproc.c
@@ -14,6 +14,7 @@
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/irqchip/arm-gic-v3.h>
+#include <linux/irqchip/chained_irq.h>
#include <linux/platform_device.h>
#include <linux/of_address.h>
#include <linux/of_pci.h>
@@ -264,6 +265,7 @@ enum iproc_pcie_reg {
/* enable INTx */
IPROC_PCIE_INTX_EN,
+ IPROC_PCIE_INTX_CSR,
/* outbound address mapping */
IPROC_PCIE_OARR0,
@@ -305,6 +307,7 @@ static const u16 iproc_pcie_reg_paxb_bcma[] = {
[IPROC_PCIE_CFG_ADDR] = 0x1f8,
[IPROC_PCIE_CFG_DATA] = 0x1fc,
[IPROC_PCIE_INTX_EN] = 0x330,
+ [IPROC_PCIE_INTX_CSR] = 0x334,
[IPROC_PCIE_LINK_STATUS] = 0xf0c,
};
@@ -316,6 +319,7 @@ static const u16 iproc_pcie_reg_paxb[] = {
[IPROC_PCIE_CFG_ADDR] = 0x1f8,
[IPROC_PCIE_CFG_DATA] = 0x1fc,
[IPROC_PCIE_INTX_EN] = 0x330,
+ [IPROC_PCIE_INTX_CSR] = 0x334,
[IPROC_PCIE_OARR0] = 0xd20,
[IPROC_PCIE_OMAP0] = 0xd40,
[IPROC_PCIE_OARR1] = 0xd28,
@@ -332,6 +336,7 @@ static const u16 iproc_pcie_reg_paxb_v2[] = {
[IPROC_PCIE_CFG_ADDR] = 0x1f8,
[IPROC_PCIE_CFG_DATA] = 0x1fc,
[IPROC_PCIE_INTX_EN] = 0x330,
+ [IPROC_PCIE_INTX_CSR] = 0x334,
[IPROC_PCIE_OARR0] = 0xd20,
[IPROC_PCIE_OMAP0] = 0xd40,
[IPROC_PCIE_OARR1] = 0xd28,
@@ -782,9 +787,90 @@ static int iproc_pcie_check_link(struct
iproc_pcie *pcie)
return link_is_active ? 0 : -ENODEV;
}
-static void iproc_pcie_enable(struct iproc_pcie *pcie)
+static int iproc_pcie_intx_map(struct irq_domain *domain, unsigned
int irq,
+ irq_hw_number_t hwirq)
{
+ irq_set_chip_and_handler(irq, &dummy_irq_chip, handle_simple_irq);
+ irq_set_chip_data(irq, domain->host_data);
+
+ return 0;
+}
+
+static const struct irq_domain_ops intx_domain_ops = {
+ .map = iproc_pcie_intx_map,
+};
+
+static void iproc_pcie_isr(struct irq_desc *desc)
+{
+ struct irq_chip *chip = irq_desc_get_chip(desc);
+ struct iproc_pcie *pcie;
+ struct device *dev;
+ unsigned long status;
+ u32 bit, virq;
+
+ chained_irq_enter(chip, desc);
+ pcie = irq_desc_get_handler_data(desc);
+ dev = pcie->dev;
+
+ /* go through INTx A, B, C, D until all interrupts are handled */
+ while ((status = iproc_pcie_read_reg(pcie, IPROC_PCIE_INTX_CSR) &
+ SYS_RC_INTX_MASK) != 0) {
+ for_each_set_bit(bit, &status, PCI_NUM_INTX) {
+ virq = irq_find_mapping(pcie->irq_domain, bit + 1);
+ if (virq)
+ generic_handle_irq(virq);
+ else
+ dev_err(dev, "unexpected INTx%u\n", bit);
+ }
+ }
+
