mips: ralink: mt7621: define MT7621_SYSC_BASE with __iomem

So that MT7621_SYSC_BASE can be used later in multiple functions without
needing to repeat this __iomem declaration each time

Signed-off-by: John Thomson <git@johnthomson.fastmail.com.au>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

MIPS: ralink: mt7621: add memory detection support

mt7621 has the following memory map:
0x0-0x1c000000: lower 448m memory
0x1c000000-0x2000000: peripheral registers
0x20000000-0x2400000: higher 64m memory

detect_memory_region in arch/mips/kernel/setup.c only adds the first
memory region and isn't suitable for 512m memory detection because
it may accidentally read the memory area for peripheral registers.

This commit adds memory detection capability for mt7621:
1. Add the highmem area when 512m is detected.
2. Guard memcmp from accessing peripheral registers:
This only happens when a user decided to change kernel load address
to 256m or higher address. Since this is a quite unusual case, we
just skip 512m testing and return 256m as memory size.

Signed-off-by: Chuanhong Guo <gch981213@gmail.com>
[Minor commit message reword, make mt7621_memory_detect static]
Signed-off-by: Ilya Lipnitskiy <ilya.lipnitskiy@gmail.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

MIPS: Kill MIPS_GIC_IRQ_BASE

It never got used by any driver.

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500

Based on 2 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation #

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Revert "MIPS: ralink: fix cpu clock of mt7621 and add dt clk devices"

Commit e6046b5e69a0 ("MIPS: ralink: fix cpu clock of mt7621 and add dt
clk devices") includes a file that doesn't exist, causing build
failures... Revert it.

References: https://lore.kernel.org/linux-mips/CAJsYDVJvviz8a2oVmb0XL3OB+=Eecu-3kC9T9vsmxpuC_BqDSA@mail.gmail.com/
Signed-off-by: Paul Burton <paul.burton@mips.com>

MIPS: ralink: fix cpu clock of mt7621 and add dt clk devices

For a long time the mt7621 uses a fixed cpu clock which causes a problem
if the cpu frequency is not 880MHz.

This patch fixes the cpu clock calculation and adds the cpu/bus clkdev
which will be used in dts.

Ported from OpenWrt:
c7ca224299 ramips: fix cpu clock of mt7621 and add dt clk devices

Signed-off-by: Weijie Gao <hackpascal@gmail.com>
Signed-off-by: Chuanhong Guo <gch981213@gmail.com>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: linux-mips@vger.kernel.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: John Crispin <john@phrozen.org>
Cc: linux-kernel@vger.kernel.org

MIPS: Change my email address

The old address is no longer valid. Use the my new one instead.

Signed-off-by: John Crispin <john@phrozen.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13201/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

MIPS: ralink: add MT7621 support

MT7621 is based on a 1004k core. This patch adds support for the SoC. The
timer and IRQ is just boiler plate as GIC has recently been moved to
generic places in the kernel and just works.

Signed-off-by: John Crispin <blogic@openwrt.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/11990/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>