On Fri, Jan 23, 2015 at 05:32:37PM -0500, Murali Karicheri wrote:
> Add of_pci_dma_configure() to allow updating the dma configuration
> of the pci device using the configuration from DT of the parent of
> the root bridge device.
>
> Cc: Joerg Roedel <joro@xxxxxxxxxx>
> Cc: Grant Likely <grant.likely@xxxxxxxxxx>
> Cc: Rob Herring <robh+dt@xxxxxxxxxx>
> Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> Cc: Will Deacon <will.deacon@xxxxxxx>
> Cc: Russell King <linux@xxxxxxxxxxxxxxxx>
> Cc: Arnd Bergmann <arnd@xxxxxxxx>
> Cc: Suravee Suthikulpanit <Suravee.Suthikulpanit@xxxxxxx>
>
> Signed-off-by: Murali Karicheri <m-karicheri2@xxxxxx>
> ---
> drivers/of/of_pci.c | 39 +++++++++++++++++++++++++++++++++++++++
> include/linux/of_pci.h | 12 ++++++++++++
> 2 files changed, 51 insertions(+)
>
> diff --git a/drivers/of/of_pci.c b/drivers/of/of_pci.c
> index 88471d3..34878c9 100644
> --- a/drivers/of/of_pci.c
> +++ b/drivers/of/of_pci.c
> @@ -2,6 +2,7 @@
> #include <linux/export.h>
> #include <linux/of.h>
> #include <linux/of_address.h>
> +#include <linux/of_device.h>
> #include <linux/of_pci.h>
> #include <linux/slab.h>
>
> @@ -229,6 +230,44 @@ parse_failed:
> return err;
> }
> EXPORT_SYMBOL_GPL(of_pci_get_host_bridge_resources);
> +
> +/**
> + * of_get_pci_root_bridge_parent - get the OF node of the root bridge's parent
> + * @dev: ptr to pci_dev struct of the pci device
> + *
> + * This function will traverse the bus up to the root bus starting with
> + * the child and return the OF node ptr to root bridge device's parent device.
> + */
> +struct device_node *of_get_pci_root_bridge_parent(struct pci_dev *dev)
I'm not an OF person, but this interface seems like it might be too
special-purpose. Maybe it would be enough to add
"of_get_pci_root_bridge()", and the caller could do this:
struct device *bridge = of_get_pci_root_bridge(dev);
struct device_node *parent_np = bridge->parent->of_node;
Also, the name "of_get_..." suggests that it increments a refcount, as
of_get_parent() does. But you aren't doing anything with the refcount.
But I guess an "of_get_pci_root_bridge()" isn't doing anything OF-related,
so maybe we should just add a "pci_get_host_bridge(struct pci_dev *)"
to PCI instead.
Bjorn
> +{
> + struct pci_bus *bus = dev->bus;
> + struct device *bridge;
> +
> + while (!pci_is_root_bus(bus))
> + bus = bus->parent;
> + bridge = bus->bridge;
> +
> + return bridge->parent->of_node;
> +}
> +EXPORT_SYMBOL_GPL(of_get_pci_root_bridge_parent);
> +
> +/**
> + * of_pci_dma_configure - Setup DMA configuration
> + * @dev: ptr to pci_dev struct of the pci device
> + *
> + * Function to update PCI devices's DMA configuration using the same
> + * info from the OF node of root host bridge's parent.
> + */
> +void of_pci_dma_configure(struct pci_dev *pci_dev)
> +{
> + struct device *dev = &pci_dev->dev;
> + struct device_node *parent_np;
> +
> + parent_np = of_get_pci_root_bridge_parent(pci_dev);
> + of_dma_configure(dev, parent_np);
> +}
> +EXPORT_SYMBOL_GPL(of_pci_dma_configure);
> +
> #endif /* CONFIG_OF_ADDRESS */
>
> #ifdef CONFIG_PCI_MSI
> diff --git a/include/linux/of_pci.h b/include/linux/of_pci.h
> index ce0e5ab..0465a2a 100644
> --- a/include/linux/of_pci.h
> +++ b/include/linux/of_pci.h
> @@ -16,6 +16,8 @@ int of_pci_get_devfn(struct device_node *np);
> int of_irq_parse_and_map_pci(const struct pci_dev *dev, u8 slot, u8 pin);
> int of_pci_parse_bus_range(struct device_node *node, struct resource *res);
> int of_get_pci_domain_nr(struct device_node *node);
> +struct device_node *of_get_pci_root_bridge_parent(struct pci_dev *dev);
> +void of_pci_dma_configure(struct pci_dev *pci_dev);
> #else
> static inline int of_irq_parse_pci(const struct pci_dev *pdev, struct of_phandle_args *out_irq)
> {
> @@ -50,6 +52,16 @@ of_get_pci_domain_nr(struct device_node *node)
> {
> return -1;
> }
> +
> +static inline struct device_node
> +*of_get_pci_root_bridge_parent(struct pci_dev *dev)
> +{
> + return NULL;
> +}
> +
> +static inline void of_pci_dma_configure(struct pci_dev *pci_dev)
> +{
> +}
> #endif
>
> #if defined(CONFIG_OF_ADDRESS)
> --
> 1.7.9.5
>
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