The following scheme applies for each pci-amba device within the
devicetree:
* sta2x11 pci express port (pci id = 0xcc17)
|
|
* pci-amba bridge node (pci id = 0xcc18)
|
+-------+
| |
| * amba-bus node (ranges, interrupt-map)
| |
| ...
... |
| * amba side of pci-amba device
|
|
* pci side of pci-amba device
As far as the sta2x11 is concerned, there are 4 pci-amba bridge nodes (one
for each pci express endpoint).
A pci-amba bridge node contains an amba bus and all the pci side parts of
the pci-amba devices attached to the same pci express endpoint.
Finally, each child node of the amba bus represents the amba side of a
pci-amba device.
Signed-off-by: Davide Ciminaghi <cimina...@gnudd.com>
Acked-by: Giancarlo Asnaghi <giancarlo.asna...@st.com>
---
drivers/amba/pci-amba.c | 126 ++++++++++++++++++++++++++++++++++++++++------
1 files changed, 109 insertions(+), 17 deletions(-)
diff --git a/drivers/amba/pci-amba.c b/drivers/amba/pci-amba.c
index 8ce526a..e56717b 100644
--- a/drivers/amba/pci-amba.c
+++ b/drivers/amba/pci-amba.c
@@ -12,42 +12,134 @@
#include <linux/slab.h>
#include <linux/irq.h>
#include <linux/sizes.h>
+#include <linux/of_address.h>
+#include <linux/of_platform.h>
+
+/*
+ Length of an interrupt map row:
+ Child unit address (amba node, length is 1) +
+ Child interrupt specifier (amba node, length is 1) +
+ Interrupt parent (phandle, length is 1) +
+ Parent unit address (parent is msi controller, length is 1)
+ Parent interrupt specifier (parent is msi controller, length is 1)
+*/
+#define IMAP_ROW_LEN (1 + 1 + 1 + 1 + 1)
static int pci_amba_probe(struct pci_dev *pdev,
const struct pci_device_id *id)
{
struct amba_device *adev;
+ int i, ret, len;
+ struct device_node *n, *node, *pci_amba_bridge, *amba_bus = NULL,
+ *amba_node = NULL;
+ const void *p;
char *name;
- int ret;
+ struct property *newimap;
+ u32 *newv, *ptr;
+ const u32 *reg;
+ int found;
pci_enable_msi(pdev);
ret = pci_enable_device(pdev);
if (ret)
return ret;
- /* Create a name: each of them must be different */
+ /* This bridge can host both APB and AHB devices, so set master */
+ pci_set_master(pdev);
+
+ node = pdev->dev.of_node;
+ if (!node)
+ return -EINVAL;
+
+ /* Get a reference to the pci amba bridge (our pci parent) */
+ pci_amba_bridge = of_get_parent(node);
+ if (!pci_amba_bridge)
+ return -EINVAL;
+ if (of_node_cmp(pci_amba_bridge->type, "pci"))
+ return -EINVAL;
+
+ /* Look for the relevant amba bus node */
+ for_each_child_of_node(pci_amba_bridge, n) {
+ if (of_device_is_compatible(n, "arm,amba-bus")) {
+ amba_bus = n;
+ break;
+ }
+ }
+ of_node_put(pci_amba_bridge);
+ if (!amba_bus)
+ return -ENODEV;
+
+ /*
+ Now find out what the relevant amba device is by looking for
+ a resource with the same initial address of this pci device's BAR0
+ */
+ for_each_child_of_node(amba_bus, n) {
+ struct resource r;
+ if (of_address_to_resource(n, 0, &r))
+ continue;
+ if (r.start == pdev->resource[0].start) {
+ amba_node = n;
+ break;
+ }
+ }
+ if (!amba_node)
+ return -ENODEV;
+
+ /* Create a unique name for the device */
name = devm_kzalloc(&pdev->dev, strlen(dev_name(&pdev->dev)) + 6,
- GFP_KERNEL);
+ GFP_KERNEL);
sprintf(name, "amba-%s", dev_name(&pdev->dev));
- /* Simply build an amba device and register it */
- adev = amba_device_alloc(name, pdev->resource[0].start, SZ_4K);
- if (!adev)
- return -ENOMEM;
- adev->irq[0] = pdev->irq;
+ /*
+ Since we're dealing with MSI IRQs, the value of a device's IRQ
+ number is known at runtime only. Update the amba bus interrupt
+ map to fix things up.
+ */
+ if (of_get_property(amba_node, "interrupts", NULL)) {
+ p = of_get_property(amba_bus, "interrupt-map", &len);
+ if (!p)
+ /* No amba bus interrupt-map property */
+ return -EINVAL;
- /* This bridge can host both APB and AHB devices, so set master */
- pci_set_master(pdev);
- if (pdev->vendor == PCI_VENDOR_ID_STMICRO) {
- /* Under sta2x11, DMA is there but limited to 512M */
- adev->dma_mask = SZ_512M - 1;
- adev->dev.coherent_dma_mask = SZ_512M - 1;
+ newimap = devm_kzalloc(&pdev->dev, sizeof(*newimap),
+ GFP_KERNEL);
+ if (!newimap)
+ return -ENOMEM;
+
+ newimap->name = kstrdup("interrupt-map", GFP_KERNEL);
+ if (!newimap->name)
+ return -ENOMEM;
+
+ newv = devm_kzalloc(&pdev->dev, len, GFP_KERNEL);
+ if (!newv) {
+ kfree(newimap->name);
+ return -ENOMEM;
+ }
+
+ newimap->value = newv;
+ newimap->length = len;
+ memcpy(newv, p, len);
+ for (ptr = newv, i = 0, found = 0;
+ i < len/sizeof(u32);
+ ptr += IMAP_ROW_LEN, i += IMAP_ROW_LEN) {
+ reg = of_get_property(amba_node, "reg", NULL);
+ if (ptr[0] == reg[0]) {
+ ptr[IMAP_ROW_LEN - 1] = cpu_to_be32(pdev->irq);
+ found = 1;
+ break;
+ }
+ }
+ if (!found) {
+ pr_err("Could not update amba irq\n");
+ return -EINVAL;
+ }
+ of_update_property(amba_bus, newimap);
}
- adev->dev.platform_data = pdev->dev.platform_data;
+ /* And finally create the amba device */
+ adev = of_amba_device_create(n, name, NULL, NULL, &pdev->resource[0]);
pci_set_drvdata(pdev, adev);
-
- return amba_device_add(adev, &pdev->resource[0]);
+ return 0;
};
static void pci_amba_remove(struct pci_dev *pdev)
--
1.7.7.2
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