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....@gmail.com>
Cc: Paulius Zaleckas <paulius.zalec...@gmail.com>
Cc: Hans Ulli Kroll <ulli.kr...@googlemail.com>
Cc: Florian Fainelli <f.faine...@gmail.com>
Signed-off-by: Linus Walleij <linus.wall...@linaro.org>
---
ChangeLog v1->v2:
- Just use CONFIG_DEBUG_UART_PHYS / CONFIG_DEBUG_UART_VIRT directly
in the iomap, works like a charm and saves more hardcoded constants.
We have to add an ifedf for debugging but that should be fine.
---
arch/arm/Kconfig | 8 ++++++++
arch/arm/mach-gemini/Makefile | 2 +-
arch/arm/mach-gemini/board-dt.c | 38 ++++++++++++++++++++++++++++++++++++++
3 files changed, 47 insertions(+), 1 deletion(-)
create mode 100644 arch/arm/mach-gemini/board-dt.c
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 63e61bf5aab0..b4a42d599e2c 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -355,11 +355,19 @@ config ARM_SINGLE_ARMV7M
config ARCH_GEMINI
bool "Cortina Systems Gemini"
+ select ARM_APPENDED_DTB # Old Redboot bootloaders deployed
select CLKSRC_MMIO
+ select CLKSRC_OF
select CPU_FA526
+ select GEMINI_TIMER
select GENERIC_CLOCKEVENTS
+ 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 7963a77be637..11f07fb6ec3d 100644
--- 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
index 000000000000..208ea99cdc47
--- /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
--
2.9.3
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