ARM: nomadik: initial devicetree support

Support basic device tree boot on the Nomadik. Implement the
support in the cpu file with the intent of deleting the board
files later. At this stage IRQ controllers, system timer,
l2x0 cache, UARTs and thus console boot is fully functional.
Patch out the code adding devices by initcalls for now so
as not to disturb the boot.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

4 files changed, 87 insertions, 1 deletions

diff --git a/arch/arm/mach-nomadik/board-nhk8815.c b/arch/arm/mach-nomadik/board-nhk8815.c
index 72ec3fad2ba6..d152d7bdf411 100644
--- a/arch/arm/mach-nomadik/board-nhk8815.c
+++ b/arch/arm/mach-nomadik/board-nhk8815.c
@@ -204,6 +204,10 @@ static int __init nhk8815_mmcsd_init(void)
 {
         int ret;
 
+        /* For e.g. devicetree boot */
+        if (!machine_is_nomadik())
+                return 0;
+
         ret = gpio_request(112, "card detect bias");
         if (ret)
                 return ret;
diff --git a/arch/arm/mach-nomadik/cpu-8815.c b/arch/arm/mach-nomadik/cpu-8815.c
index 351404673f6c..7c8e3487f4eb 100644
--- a/arch/arm/mach-nomadik/cpu-8815.c
+++ b/arch/arm/mach-nomadik/cpu-8815.c
@@ -25,13 +25,19 @@
 #include <linux/slab.h>
 #include <linux/irq.h>
 #include <linux/dma-mapping.h>
-#include <linux/irqchip/arm-vic.h>
+#include <linux/irqchip.h>
 #include <linux/platform_data/clk-nomadik.h>
 #include <linux/platform_data/pinctrl-nomadik.h>
+#include <linux/platform_data/clocksource-nomadik-mtu.h>
+#include <linux/of_irq.h>
+#include <linux/of_address.h>
+#include <linux/of_platform.h>
 
 #include <mach/hardware.h>
 #include <mach/irqs.h>
+#include <asm/mach/arch.h>
 #include <asm/mach/map.h>
+#include <asm/mach/time.h>
 
 #include <asm/cacheflush.h>
 #include <asm/hardware/cache-l2x0.h>
@@ -160,3 +166,73 @@ void cpu8815_restart(char mode, const char *cmd)
         /* Write anything to Reset status register */
         writel(1, src_rstsr);
 }
+
+#ifdef CONFIG_OF
+
+/* Initial value for SRC control register: all timers use MXTAL/8 source */
+#define SRC_CR_INIT_MASK        0x00007fff
+#define SRC_CR_INIT_VAL         0x2aaa8000
+
+static void __init cpu8815_timer_init_of(void)
+{
+        struct device_node *mtu;
+        void __iomem *base;
+        int irq;
+        u32 src_cr;
+
+        /* We need this to be up now */
+        nomadik_clk_init();
+
+        mtu = of_find_node_by_path("/mtu0");
+        if (!mtu)
+                return;
+        base = of_iomap(mtu, 0);
+        if (WARN_ON(!base))
+                return;
+        irq = irq_of_parse_and_map(mtu, 0);
+
+        pr_info("Remapped MTU @ %p, irq: %d\n", base, irq);
+
+        /* Configure timer sources in "system reset controller" ctrl reg */
+        src_cr = readl(base);
+        src_cr &= SRC_CR_INIT_MASK;
+        src_cr |= SRC_CR_INIT_VAL;
+        writel(src_cr, base);
+
+        nmdk_timer_init(base, irq);
+}
+
+/* These are mostly to get the right device names for the clock lookups */
+static struct of_dev_auxdata cpu8815_auxdata_lookup[] __initdata = {
+        OF_DEV_AUXDATA("arm,primecell", NOMADIK_UART0_BASE,
+                "uart0", NULL),
+        OF_DEV_AUXDATA("arm,primecell", NOMADIK_UART1_BASE,
+                "uart1", NULL),
+        { /* sentinel */ },
+};
+
+static void __init cpu8815_init_of(void)
+{
+#ifdef CONFIG_CACHE_L2X0
+        /* At full speed latency must be >=2, so 0x249 in low bits */
+        l2x0_of_init(0x00730249, 0xfe000fff);
+#endif
+        of_platform_populate(NULL, of_default_bus_match_table,
+                        cpu8815_auxdata_lookup, NULL);
+}
+
+static const char * cpu8815_board_compat[] = {
+        "calaosystems,usb-s8815",
+        NULL,
+};
+
+DT_MACHINE_START(NOMADIK_DT, "Nomadik STn8815")
+        .map_io         = cpu8815_map_io,
+        .init_irq       = irqchip_init,
+        .init_time      = cpu8815_timer_init_of,
+        .init_machine   = cpu8815_init_of,
+        .restart        = cpu8815_restart,
+        .dt_compat      = cpu8815_board_compat,
+MACHINE_END
+
+#endif
diff --git a/arch/arm/mach-nomadik/cpu-8815.h b/arch/arm/mach-nomadik/cpu-8815.h
index 71c21e8a11dc..d6c7830e4799 100644
--- a/arch/arm/mach-nomadik/cpu-8815.h
+++ b/arch/arm/mach-nomadik/cpu-8815.h
@@ -2,3 +2,4 @@ extern void cpu8815_map_io(void);
 extern void cpu8815_platform_init(void);
 extern void cpu8815_init_irq(void);
 extern void cpu8815_restart(char, const char *);
+extern struct sys_timer cpu8815_timer;
diff --git a/arch/arm/mach-nomadik/i2c-8815nhk.c b/arch/arm/mach-nomadik/i2c-8815nhk.c
index f0e9e64f731a..299ff5a687bc 100644
--- a/arch/arm/mach-nomadik/i2c-8815nhk.c
+++ b/arch/arm/mach-nomadik/i2c-8815nhk.c
@@ -4,6 +4,7 @@
 #include <linux/i2c-algo-bit.h>
 #include <linux/i2c-gpio.h>
 #include <linux/platform_device.h>
+#include <asm/mach-types.h>
 
 /*
  * There are two busses in the 8815NHK.
@@ -58,6 +59,10 @@ static struct platform_device nhk8815_i2c_dev2 = {
 
 static int __init nhk8815_i2c_init(void)
 {
+        /* For e.g. devicetree boot */
+        if (!machine_is_nomadik())
+                return 0;
+
         platform_device_register(&nhk8815_i2c_dev0);
         platform_device_register(&nhk8815_i2c_dev1);
         platform_device_register(&nhk8815_i2c_dev2);