* Pekon Gupta <pekon@xxxxxx> [140723 11:20]:
> Each GPMC chip-select needs to be configured for (base-address,CS-size) so that
> GPMC understands the address-space allocated to device connected externally.
> These chip-select configurations (base-address, CS-size) follow some basic
> mapping rules like:
> - The CS size is programmable from 256 MBytes to 16 MBytes (must be a power of 2)
> and is defined by the mask field. Attached memory smaller than the programmed
> CS region size is accessed through the entire CS region (aliasing).
> - The programmed 'base-address' must be aligned to the 'CS-size' boundary and
> be a power of 2.
> - Valid CS-size values are {256MB(max), 128MB, 64MB, 32MB and 16MB (min)}
> Any intermediate values creates holes in the chip-select memory-map.
>
> This patch adds above checks in gpmc_cs_remap() so that any invalid value
> passed by DT <reg> property can be filtered before actually allocating the
> address space.
>
> Signed-off-by: Pekon Gupta <pekon@xxxxxx>
Looks like size typos Roger mentioned are fixed in this one, so
applying into omap-for-v3.17/fixes thanks.
Tony
> ---
> arch/arm/mach-omap2/gpmc.c | 42 +++++++++++++++++++++++++++++-------------
> 1 file changed, 29 insertions(+), 13 deletions(-)
>
> diff --git a/arch/arm/mach-omap2/gpmc.c b/arch/arm/mach-omap2/gpmc.c
> index 8bc1338..4a4cc04 100644
> --- a/arch/arm/mach-omap2/gpmc.c
> +++ b/arch/arm/mach-omap2/gpmc.c
> @@ -521,26 +521,42 @@ static int gpmc_cs_delete_mem(int cs)
> * "base". Returns 0 on success and appropriate negative error code
> * on failure.
> */
> -static int gpmc_cs_remap(int cs, u32 base)
> +static int gpmc_cs_remap(int cs, u32 base, u32 size)
> {
> int ret;
> - u32 old_base, size;
>
> if (cs > gpmc_cs_num) {
> pr_err("%s: requested chip-select is disabled\n", __func__);
> return -ENODEV;
> }
>
> - /*
> - * Make sure we ignore any device offsets from the GPMC partition
> - * allocated for the chip select and that the new base confirms
> - * to the GPMC 16MB minimum granularity.
> - */
> - base &= ~(SZ_16M - 1);
> -
> - gpmc_cs_get_memconf(cs, &old_base, &size);
> - if (base == old_base)
> - return 0;
> + /* allocate enough address-space under GPMC chip-select to device */
> + if (size > SZ_256M) {
> + pr_err("%s: memory device > 256MB not supported\n", __func__);
> + return -ENODEV;
> + } else if (size > SZ_128M) {
> + WARN((size != SZ_256M), "cs=%d: allocating 256MB\n", cs);
> + size = SZ_256M;
> + } else if (size > SZ_64M) {
> + WARN((size != SZ_128M), "cs=%d: allocating 128MB\n", cs);
> + size = SZ_128M;
> + } else if (size > SZ_32M) {
> + WARN((size != SZ_64M), "cs=%d: allocating 64MB\n", cs);
> + size = SZ_64M;
> + } else if (size > SZ_16M) {
> + WARN((size != SZ_32M), "cs=%d: allocating 64MB\n", cs);
> + size = SZ_32M;
> + } else {
> + WARN((size != SZ_16M), "cs=%d: allocating 64MB\n", cs);
> + size = SZ_16M;
> + }
> +
> + /* base address should be aligned with address-space size */
> + if (base & (size - 1)) {
> + pr_err("base-addr=%x should be aligned to size=%x", base, size);
> + return -EINVAL;
> + }
> +
> gpmc_cs_disable_mem(cs);
> ret = gpmc_cs_delete_mem(cs);
> if (ret < 0)
> @@ -1551,7 +1567,7 @@ static int gpmc_probe_generic_child(struct platform_device *pdev,
> * CS to this location. Once DT migration is complete should
> * just make gpmc_cs_request() map a specific address.
> */
> - ret = gpmc_cs_remap(cs, res.start);
> + ret = gpmc_cs_remap(cs, res.start, resource_size(&res));
> if (ret < 0) {
> dev_err(&pdev->dev, "cannot remap GPMC CS %d to %pa\n",
> cs, &res.start);
> --
> 1.8.5.1.163.gd7aced9
>
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