[PATCH v10 1/7] of: Provide function to request and map memory

[Rob Herring]

On Mon, Jul 7, 2014 at 10:13 AM, Matthias Brugger
<matthias.bgg at gmail.com> wrote:
> A call to of_iomap does not request the memory region.
> This patch adds the function of_io_request_and_map which requests
> the memory region before mapping it.
>
> Signed-off-by: Matthias Brugger <matthias.bgg at gmail.com>
> Suggested-by: Thomas Gleixner <tglx at linutronix.de>
> Suggested-by: Rob Herring <robh at kernel.org>

Acked-by: Rob Herring <robh at kernel.org>

> ---
>  drivers/of/address.c       |   36 ++++++++++++++++++++++++++++++++++++
>  include/linux/io.h         |    2 ++
>  include/linux/of_address.h |   11 +++++++++++
>  lib/devres.c               |    2 --
>  4 files changed, 49 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/of/address.c b/drivers/of/address.c
> index 5edfcb0..e371825 100644
> --- a/drivers/of/address.c
> +++ b/drivers/of/address.c
> @@ -702,6 +702,42 @@ void __iomem *of_iomap(struct device_node *np, int index)
>  }
>  EXPORT_SYMBOL(of_iomap);
>
> +/*
> + * of_io_request_and_map - Requests a resource and maps the memory mapped IO
> + *                        for a given device_node
> + * @device:    the device whose io range will be mapped
> + * @index:     index of the io range
> + * @name:      name of the resource
> + *
> + * Returns a pointer to the requested and mapped memory or an ERR_PTR() encoded
> + * error code on failure. Usage example:
> + *
> + *     base = of_io_request_and_map(node, 0, "foo");
> + *     if (IS_ERR(base))
> + *             return PTR_ERR(base);
> + */
> +void __iomem *of_io_request_and_map(struct device_node *np, int index,
> +                                       char *name)
> +{
> +       struct resource res;
> +       void __iomem *mem;
> +
> +       if (of_address_to_resource(np, index, &res))
> +               return IOMEM_ERR_PTR(-EINVAL);
> +
> +       if (!request_mem_region(res.start, resource_size(&res), name))
> +               return IOMEM_ERR_PTR(-EBUSY);
> +
> +       mem = ioremap(res.start, resource_size(&res));
> +       if (!mem) {
> +               release_mem_region(res.start, resource_size(&res));
> +               return IOMEM_ERR_PTR(-ENOMEM);
> +       }
> +
> +       return mem;
> +}
> +EXPORT_SYMBOL(of_io_request_and_map);
> +
>  /**
>   * of_dma_get_range - Get DMA range info
>   * @np:                device node to get DMA range info
> diff --git a/include/linux/io.h b/include/linux/io.h
> index b76e6e5..d5fc9b8 100644
> --- a/include/linux/io.h
> +++ b/include/linux/io.h
> @@ -58,6 +58,8 @@ static inline void devm_ioport_unmap(struct device *dev, void __iomem *addr)
>  }
>  #endif
>
> +#define IOMEM_ERR_PTR(err) (__force void __iomem *)ERR_PTR(err)
> +
>  void __iomem *devm_ioremap(struct device *dev, resource_size_t offset,
>                             unsigned long size);
>  void __iomem *devm_ioremap_nocache(struct device *dev, resource_size_t offset,
> diff --git a/include/linux/of_address.h b/include/linux/of_address.h
> index c13b878..fb7b722 100644
> --- a/include/linux/of_address.h
> +++ b/include/linux/of_address.h
> @@ -109,7 +109,12 @@ static inline bool of_dma_is_coherent(struct device_node *np)
>  extern int of_address_to_resource(struct device_node *dev, int index,
>                                   struct resource *r);
>  void __iomem *of_iomap(struct device_node *node, int index);
> +void __iomem *of_io_request_and_map(struct device_node *device,
> +                                       int index, char *name);
>  #else
> +
> +#include <linux/io.h>
> +
>  static inline int of_address_to_resource(struct device_node *dev, int index,
>                                          struct resource *r)
>  {
> @@ -120,6 +125,12 @@ static inline void __iomem *of_iomap(struct device_node *device, int index)
>  {
>         return NULL;
>  }
> +
> +static inline void __iomem *of_io_request_and_map(struct device_node *device,
> +                                       int index, char *name)
> +{
> +       return IOMEM_ERR_PTR(-EINVAL);
> +}
>  #endif
>
>  #if defined(CONFIG_OF_ADDRESS) && defined(CONFIG_PCI)
> diff --git a/lib/devres.c b/lib/devres.c
> index f562bf6..bb63248 100644
> --- a/lib/devres.c
> +++ b/lib/devres.c
> @@ -86,8 +86,6 @@ void devm_iounmap(struct device *dev, void __iomem *addr)
>  }
>  EXPORT_SYMBOL(devm_iounmap);
>
> -#define IOMEM_ERR_PTR(err) (__force void __iomem *)ERR_PTR(err)
> -
>  /**
>   * devm_ioremap_resource() - check, request region, and ioremap resource
>   * @dev: generic device to handle the resource for
> --
> 1.7.9.5
>