[PATCH v2 02/08] PCI: rcar: add error interrupt handling

Magnus Damm
2014-02-18T02:09:50Z

From: Ben Dooks <ben.dooks@codethink.co.uk>

Add option to enable interrupts to report any errors from
the AHB-PCI bridge to help find any issues with the bridge
when in use.

Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
Signed-off-by: Magnus Damm <damm@opensource.se>
---

v2:
- removed kconfig entry and use CONFIG_PCI_DEBUG
- check for irq > 0 before trying to attach irq

drivers/pci/host/pci-rcar-gen2.c | 60 ++++++++++++++++++++++++++++++++++++++
1 file changed, 60 insertions(+)

--- 0004/drivers/pci/host/pci-rcar-gen2.c
+++ work/drivers/pci/host/pci-rcar-gen2.c 2014-02-13 09:42:56.000000000 +0900
@@ -39,9 +39,26 @@

#define RCAR_PCI_INT_ENABLE_REG (RCAR_AHBPCI_PCICOM_OFFSET + 0x20)
#define RCAR_PCI_INT_STATUS_REG (RCAR_AHBPCI_PCICOM_OFFSET + 0x24)
+#define RCAR_PCI_INT_SIGTABORT (1 << 0)
+#define RCAR_PCI_INT_SIGRETABORT (1 << 1)
+#define RCAR_PCI_INT_REMABORT (1 << 2)
+#define RCAR_PCI_INT_PERR (1 << 3)
+#define RCAR_PCI_INT_SIGSERR (1 << 4)
+#define RCAR_PCI_INT_RESERR (1 << 5)
+#define RCAR_PCI_INT_WIN1ERR (1 << 12)
+#define RCAR_PCI_INT_WIN2ERR (1 << 13)
#define RCAR_PCI_INT_A (1 << 16)
#define RCAR_PCI_INT_B (1 << 17)
#define RCAR_PCI_INT_PME (1 << 19)
+#define RCAR_PCI_INT_ALLERRORS (RCAR_PCI_INT_SIGTABORT | \
+ RCAR_PCI_INT_SIGRETABORT | \
+ RCAR_PCI_INT_SIGRETABORT | \
+ RCAR_PCI_INT_REMABORT | \
+ RCAR_PCI_INT_PERR | \
+ RCAR_PCI_INT_SIGSERR | \
+ RCAR_PCI_INT_RESERR | \
+ RCAR_PCI_INT_WIN1ERR | \
+ RCAR_PCI_INT_WIN2ERR)

#define RCAR_AHB_BUS_CTR_REG (RCAR_AHBPCI_PCICOM_OFFSET + 0x30)
#define RCAR_AHB_BUS_MMODE_HTRANS (1 << 0)
@@ -164,6 +181,46 @@ static int __init rcar_pci_map_irq(const
return priv->irq;
}

+#ifdef CONFIG_PCI_DEBUG
+/* if debug enabled, then attach an error handler irq to the bridge */
+
+static irqreturn_t rcar_pci_err_irq(int irq, void *pw)
+{
+ struct rcar_pci_priv *priv = pw;
+ u32 status = ioread32(priv->reg + RCAR_PCI_INT_STATUS_REG);
+
+ if (status & RCAR_PCI_INT_ALLERRORS) {
+ dev_err(priv->dev, "error irq: status %08x\n", status);
+
+ /* clear the error(s) */
+ iowrite32(status & RCAR_PCI_INT_ALLERRORS,
+ priv->reg + RCAR_PCI_INT_STATUS_REG);
+ return IRQ_HANDLED;
+ }
+
+ return IRQ_NONE;
+}
+
+static void rcar_pci_setup_errirq(struct rcar_pci_priv *priv)
+{
+ int ret;
+ u32 val;
+
+ ret = devm_request_irq(priv->dev, priv->irq, rcar_pci_err_irq,
+ IRQF_SHARED, "error irq", priv);
+ if (ret) {
+ dev_err(priv->dev, "cannot claim IRQ for error handling\n");
+ return;
+ }
+
+ val = ioread32(priv->reg + RCAR_PCI_INT_ENABLE_REG);
+ val |= RCAR_PCI_INT_ALLERRORS;
+ iowrite32(val, priv->reg + RCAR_PCI_INT_ENABLE_REG);
+}
+#else
+static inline void rcar_pci_setup_errirq(struct rcar_pci_priv *priv) { }
+#endif
+
/* PCI host controller setup */
static int __init rcar_pci_setup(int nr, struct pci_sys_data *sys)
{
@@ -224,6 +281,9 @@ static int __init rcar_pci_setup(int nr,
iowrite32(RCAR_PCI_INT_A | RCAR_PCI_INT_B | RCAR_PCI_INT_PME,
reg + RCAR_PCI_INT_ENABLE_REG);

+ if (priv->irq > 0)
+ rcar_pci_setup_errirq(priv);
+
/* Add PCI resources */
pci_add_resource(&sys->resources, &priv->io_res);
pci_add_resource(&sys->resources, &priv->mem_res);