ARM: OMAP2+: Add additional GPMC timing parameters

Some of the GPMC timings parameters are currently missing from the GPMC
device-tree binding. Add these parameters to the binding documentation
as well as code to read them. Also add either "-ps" or "-ns" suffix to
the GPMC timing properties to indicate whether the timing is in
picoseconds or nanoseconds.

The existing code in gpmc_read_timings_dt() is checking the value of
of_property_read_u32() and only is successful storing the value read
in the gpmc_timings structure. Checking the return value in this case
is not necessary and we can simply read the value, if present, and
store directly in the gpmc_timings structure. Therefore, simplify the
code by removing these checks.

The comment in the gpmc_read_timings_dt() function, "only for OMAP3430"
is also incorrect as it is applicable to all OMAP3+ devices. So correct
this too.

Signed-off-by: Jon Hunter <jon-hunter@ti.com>
ARM: OMAP2+: Add device-tree support for NOR flash

NOR flash is not currently supported when booting with device-tree
on OMAP2+ devices. Add support to detect and configure NOR devices
when booting with device-tree.

Add documentation for the TI GPMC NOR binding.

Signed-off-by: Jon Hunter <jon-hunter@ti.com>
ARM: OMAP2+: Convert NAND to retrieve GPMC settings from DT

When booting with device-tree, retrieve GPMC settings for NAND from
the device-tree blob. This will allow us to remove all static settings
stored in the gpmc-nand.c in the future once the migration to
device-tree is complete.

Signed-off-by: Jon Hunter <jon-hunter@ti.com>
ARM: OMAP2+: Convert ONENAND to retrieve GPMC settings from DT

When booting with device-tree, retrieve GPMC settings for ONENAND from
the device-tree blob. This will allow us to remove all static settings
stored in the gpmc-nand.c in the future once the migration to
device-tree is complete.

The user must now specify the ONENAND device width in the device-tree
binding so that the GPMC can be programmed correctly. Therefore, update
the device-tree binding documentation for ONENAND devices connected to
the GPMC to reflect this.

Please note that this does not include GPMC timings for ONENAND. The
timings are being calculated at runtime.

There is some legacy code that only enables read wait monitoring for
non-OMAP3 devices. There are no known OMAP3 device issues that prevent
this feature being enabled and so when booting with device-tree use the
wait-monitoring settings described in the device-tree blob.

Signed-off-by: Jon Hunter <jon-hunter@ti.com>
ARM: OMAP2+: Detect incorrectly aligned GPMC base address

Each GPMC chip-select can be configured to map 16MB, 32MB, 64MB or 128MB
of address space. The physical base address where a chip-select starts
is also configurable and must be aligned on a boundary that is equal to
or greater than the size of the address space mapped bt the chip-select.
When enabling a GPMC chip-select, ensure that the base address is aligned
to the appropriate boundary.

Reported-by: Mark Jackson <mpfj-list@mimc.co.uk>
Signed-off-by: Jon Hunter <jon-hunter@ti.com>
ARM: OMAP2+: Remove unnecesssary GPMC definitions and variable

With commit 21cc2bd (ARM: OMAP2+: Remove apollon board support) the
variable "boot_rom_space" is now not needed and the code surrounding
this variable can be cleaned up and simplified. Remove unnecessary
definitions and clean-up the comment as well.

Signed-off-by: Jon Hunter <jon-hunter@ti.com>
ARM: OMAP2+: Allow GPMC probe to complete even if CS mapping fails

When the GPMC driver is probed, we call gpmc_mem_init() to see which
chip-selects have already been configured and enabled by the boot-loader
and allocate space for them. If we fail to allocate space for one
chip-select, then we return failure from the probe and the GPMC driver
will not be available.

Rather than render the GPMC useless for all GPMC devices, if we fail to
allocate space for one chip-select print a warning and disable the
chip-select. This way other GPMC clients can still be used.

There is no downside to this approach, because all GPMC clients need to
request a chip-select before they can use the GPMC and on requesting a
chip-select, if memory has not already been reserved for the chip-select
then it will be.

Signed-off-by: Jon Hunter <jon-hunter@ti.com>
ARM: OMAP2+: return -ENODEV if GPMC child device creation fails

gpmc_probe_nor_child() calls of_platform_device_create() to create a
platform device for the NOR child. If this function fails the value
of ret is returned to the caller but this value is zero since it was
assigned the return of a previous call to gpmc_cs_program_settings()
that had to succeed or otherwise gpmc_probe_nor_child() would have
returned before.

This means that if of_platform_device_create() fails, 0 will be returned
to the caller instead of an appropriate error code.

Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Signed-off-by: Jon Hunter <jon-hunter@ti.com>
ARM: OMAP2+: rename gpmc_probe_nor_child() to gpmc_probe_generic_child()

The gpmc_probe_nor_child() function is used in the GPMC driver to
configure the GPMC for a NOR child device node.

But this function is quite generic and all the NOR specific configuration
is made by the driver of the actual NOR flash memory used.

Other Pseudo-SRAM devices such as ethernet controllers need a similar
setup so by making this function generic it can be used for those too.

Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Signed-off-by: Jon Hunter <jon-hunter@ti.com>
ARM: OMAP2+: Add GPMC DT support for Ethernet child nodes

Besides being used to interface with external memory devices,
the General-Purpose Memory Controller can be used to connect
Pseudo-SRAM devices such as ethernet controllers to OMAP2+
processors using the TI GPMC as a data bus.

This patch allows an ethernet chip to be defined as an GPMC
child device node.

Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Signed-off-by: Jon Hunter <jon-hunter@ti.com>