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0c02c8007e
The OF irq handling code has been overloading the term 'map' to refer to both parsing the data in the device tree and mapping it to the internal linux irq system. This is probably because the device tree does have the concept of an 'interrupt-map' function for translating interrupt references from one node to another, but 'map' is still confusing when the primary purpose of some of the functions are to parse the DT data. This patch renames all the of_irq_map_* functions to of_irq_parse_* which makes it clear that there is a difference between the parsing phase and the mapping phase. Kernel code can make use of just the parsing or just the mapping support as needed by the subsystem. The patch was generated mechanically with a handful of sed commands. Signed-off-by: Grant Likely <grant.likely@linaro.org> Acked-by: Michal Simek <monstr@monstr.eu> Acked-by: Tony Lindgren <tony@atomide.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
93 lines
2.8 KiB
C
93 lines
2.8 KiB
C
#include <linux/kernel.h>
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#include <linux/of_pci.h>
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#include <linux/of_irq.h>
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#include <linux/export.h>
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#include <asm/prom.h>
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/**
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* of_irq_parse_pci - Resolve the interrupt for a PCI device
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* @pdev: the device whose interrupt is to be resolved
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* @out_irq: structure of_irq filled by this function
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*
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* This function resolves the PCI interrupt for a given PCI device. If a
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* device-node exists for a given pci_dev, it will use normal OF tree
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* walking. If not, it will implement standard swizzling and walk up the
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* PCI tree until an device-node is found, at which point it will finish
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* resolving using the OF tree walking.
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*/
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int of_irq_parse_pci(const struct pci_dev *pdev, struct of_irq *out_irq)
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{
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struct device_node *dn, *ppnode;
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struct pci_dev *ppdev;
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u32 lspec;
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__be32 lspec_be;
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__be32 laddr[3];
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u8 pin;
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int rc;
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/* Check if we have a device node, if yes, fallback to standard
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* device tree parsing
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*/
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dn = pci_device_to_OF_node(pdev);
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if (dn) {
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rc = of_irq_parse_one(dn, 0, out_irq);
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if (!rc)
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return rc;
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}
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/* Ok, we don't, time to have fun. Let's start by building up an
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* interrupt spec. we assume #interrupt-cells is 1, which is standard
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* for PCI. If you do different, then don't use that routine.
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*/
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rc = pci_read_config_byte(pdev, PCI_INTERRUPT_PIN, &pin);
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if (rc != 0)
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return rc;
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/* No pin, exit */
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if (pin == 0)
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return -ENODEV;
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/* Now we walk up the PCI tree */
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lspec = pin;
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for (;;) {
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/* Get the pci_dev of our parent */
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ppdev = pdev->bus->self;
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/* Ouch, it's a host bridge... */
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if (ppdev == NULL) {
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ppnode = pci_bus_to_OF_node(pdev->bus);
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/* No node for host bridge ? give up */
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if (ppnode == NULL)
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return -EINVAL;
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} else {
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/* We found a P2P bridge, check if it has a node */
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ppnode = pci_device_to_OF_node(ppdev);
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}
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/* Ok, we have found a parent with a device-node, hand over to
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* the OF parsing code.
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* We build a unit address from the linux device to be used for
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* resolution. Note that we use the linux bus number which may
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* not match your firmware bus numbering.
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* Fortunately, in most cases, interrupt-map-mask doesn't
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* include the bus number as part of the matching.
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* You should still be careful about that though if you intend
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* to rely on this function (you ship a firmware that doesn't
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* create device nodes for all PCI devices).
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*/
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if (ppnode)
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break;
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/* We can only get here if we hit a P2P bridge with no node,
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* let's do standard swizzling and try again
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*/
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lspec = pci_swizzle_interrupt_pin(pdev, lspec);
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pdev = ppdev;
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}
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lspec_be = cpu_to_be32(lspec);
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laddr[0] = cpu_to_be32((pdev->bus->number << 16) | (pdev->devfn << 8));
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laddr[1] = laddr[2] = cpu_to_be32(0);
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return of_irq_parse_raw(ppnode, &lspec_be, 1, laddr, out_irq);
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}
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EXPORT_SYMBOL_GPL(of_irq_parse_pci);
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