The watchdog driver of the SoC uses the clk API to
get the clock associated with the watchdog device.
However the MT7620 specific setup code does not
register a clock for the watchdog device yet which
leads to the following error:

  rt2880_wdt: probe of 10000120.watchdog failed with error -2

Register a clock device for the watchdog in order to
avoid the error and make the watchdog usable.
Signed-off-by: NJohn Crispin <blogic@openwrt.org>
Signed-off-by: NGabor Juhos <juhosg@openwrt.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/5756/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

The current code assumes that the peripheral clock always
runs at 40MHz which is not true in all configuration. The
peripheral clock can also use the reference clock instead
of the fixed 40MHz rate. If the reference clock runs at a
different rate, various peripheries are behaving incorrectly.

Additionally, the currectly calculated system clock is also
wrong. The actual value what the code computes is the rate
of the DRAM which can be different from the system clock.

Add new helper functions to get the rate of the different
clocks and use the correct values for the registered clock
devices.
Signed-off-by: NGabor Juhos <juhosg@openwrt.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/5755/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Make the code print which of SDRAM, DDR1 or DDR2 was detected.
Signed-off-by: NJohn Crispin <blogic@openwrt.org>
Cc: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/5671/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Populate struct soc_info with the data that describes our RAM window.
Signed-off-by: NJohn Crispin <blogic@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/5183/

Add support code for mt7620 SOC.

The code detects the SoC and registers the clk / pinmux settings.
Signed-off-by: NJohn Crispin <blogic@openwrt.org>
Acked-by: NGabor Juhos <juhosg@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/5177/