ARM: gemini: DT for the Cortina Gemini SoC platforms

This adds initial and compulsory device tree support to the
Gemini ARMv4 platform.

We are selecting a bunch of "absolute minimals" for getting a working
system up with just device tree:

- We select USE_OF for natural reasons or nothing works.

- We select CLKSRC_OF and GEMINI_TIMER so we get timekeeping from
  the clocksource.

- We select GPIO_GEMINI because these are used as irqchips, and
  for a generic driver it is not reasonable for those to have to
  select every possible irqchip in the world to work, the platform
  should simply provide the available irqchips.

- We select a UART that can be exprected to work with
  SERIAL_OF_PLATFORM which is the name for an 8250 OF-probed
  serial port.

- We select the syscon-based reset controller: it's not fun when
  "reboot" doesn't work because of Kconfig, so we just select
  POWER_RESET and POWER_RESET_SYSCON.

- We perhaps a bit controversiallt select ARM_APPENDED_DTB, because
  this platform is using the ancient RedBoot, and can *NOT* be
  expected to upgrade its bootloaders. Appended device tree is
  simply how these devices have to work with device tree.

Cc: Janos Laube <janos.dev@gmail.com>
Cc: Paulius Zaleckas <paulius.zaleckas@gmail.com>
Cc: Hans Ulli Kroll <ulli.kroll@googlemail.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 6c2b72b173c8d4968286d034ae6bbf56cca481af..637f5756dca80b8bf4ede4990aa0b24e823d02fd 100644 (file)
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -361,11 +361,17 @@ config ARM_SINGLE_ARMV7M
 
 config ARCH_GEMINI
        bool "Cortina Systems Gemini"
-       select CLKSRC_MMIO
+       select ARM_APPENDED_DTB # Old Redboot bootloaders deployed
        select CPU_FA526
-       select GENERIC_CLOCKEVENTS
+       select FARADAY_FTINTC010
+       select FTTMR010_TIMER
+       select GPIO_GEMINI
        select GPIOLIB
        select MULTI_IRQ_HANDLER
+       select POWER_RESET
+       select POWER_RESET_SYSCON
+       select SERIAL_OF_PLATFORM
+       select USE_OF
        help
          Support for the Cortina Systems Gemini family SoCs
 

diff --git a/arch/arm/mach-gemini/Makefile b/arch/arm/mach-gemini/Makefile
index 7963a77be637b9fb13ef2cded4f6f2165096f721..11f07fb6ec3d92439aa995e7c6bf76e7b0bc1a7b 100644 (file)
--- a/arch/arm/mach-gemini/Makefile
+++ b/arch/arm/mach-gemini/Makefile
@@ -4,7 +4,7 @@
 
 # Object file lists.
 
-obj-y                  := irq.o mm.o time.o devices.o gpio.o idle.o reset.o
+obj-y                  := irq.o mm.o time.o devices.o gpio.o idle.o reset.o board-dt.o
 
 # Board-specific support
 obj-$(CONFIG_MACH_NAS4220B)    += board-nas4220b.o

diff --git a/arch/arm/mach-gemini/board-dt.c b/arch/arm/mach-gemini/board-dt.c
new file mode 100644 (file)
index 0000000..208ea99
--- /dev/null
+++ b/arch/arm/mach-gemini/board-dt.c
@@ -0,0 +1,38 @@
+/*
+ * Gemini Device Tree boot support
+ */
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/io.h>
+
+#include <asm/mach/arch.h>
+#include <asm/mach/map.h>
+
+#ifdef CONFIG_DEBUG_GEMINI
+/* This is needed for LL-debug/earlyprintk/debug-macro.S */
+static struct map_desc gemini_io_desc[] __initdata = {
+       {
+               .virtual = CONFIG_DEBUG_UART_VIRT,
+               .pfn = __phys_to_pfn(CONFIG_DEBUG_UART_PHYS),
+               .length = SZ_4K,
+               .type = MT_DEVICE,
+       },
+};
+
+static void __init gemini_map_io(void)
+{
+       iotable_init(gemini_io_desc, ARRAY_SIZE(gemini_io_desc));
+}
+#else
+#define gemini_map_io NULL
+#endif
+
+static const char *gemini_board_compat[] = {
+       "cortina,gemini",
+       NULL,
+};
+
+DT_MACHINE_START(GEMINI_DT, "Gemini (Device Tree)")
+       .map_io         = gemini_map_io,
+       .dt_compat      = gemini_board_compat,
+MACHINE_END