ARM: OMAP2+: gpmc: Print error message in set_gpmc_timing_reg()

Simplify set_gpmc_timing_reg() and always print error message
if the requested timing cannot be achieved due to a too fast
GPMC functional clock, irrespective if whether DEBUG is defined
or not. This should help us debug timing configuration issues,
which were otherwise simply not being displayed in the kernel log.

Signed-off-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
ARM: OMAP2+: gpmc: Error out if timings fail in gpmc_probe_generic_child()

gpmc_cs_set_timings() returns non-zero if there was
an error while setting the GPMC timings. e.g. Timing was too
large to be accomodated with current GPMC clock frequency and available
timing range. Fail in this case, else we risk operating a NOR device
with non compliant timings.

Signed-off-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
ARM: OMAP2+: gpmc: Always enable A26-A11 for non NAND devices

Although RESET state of LIMITEDADDRESS bit in GPMC_CONFIG register
is 0 (i.e. A26-A11 enabled), faulty bootloaders might accidentally
set this bit. e.g. u-boot 2014.07 with CONFIG_NOR disabled.

Explicity disable LIMITEDADDRESS bit for non NAND devices so that
they can always work.

Signed-off-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
ARM: OMAP2+: gpmc: Keep Chip Select disabled while configuring it

As per the OMAP reference manual [1], the Chip Select must be
disabled (i.e. CSVALID is 0) while configuring any of the
Chip select parameters.

[1] - 10.1.5.1 Chip-Select Base Address and Region Size Configuration
http://www.ti.com/lit/pdf/swpu177

Signed-off-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
ARM: OMAP2+: gpmc: Sanity check GPMC fck on probe

This prevents potential division by zero errors
if GPMC fck turns out to be zero due to faulty clock
data.

Use resource managed clk_get() API.

Signed-off-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>