ARC: [DeviceTree] Convert some Kconfig items to runtime values

* mem size now runtime configured (prev CONFIG_ARC_PLAT_SDRAM_SIZE)
* core cpu clk runtime configured (prev CONFIG_ARC_PLAT_CLK)

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Grant Likely <grant.likely@secretlab.ca>

6 files changed, 37 insertions, 17 deletions

diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
index 76668579b543..7db978570fb8 100644
--- a/arch/arc/Kconfig
+++ b/arch/arc/Kconfig
@@ -249,10 +249,6 @@ source "arch/arc/plat-arcfpga/Kconfig"
 
 #New platform adds here
 
-config ARC_PLAT_CLK
-        int "Clk speed in Hz"
-        default "80000000"
-
 config LINUX_LINK_BASE
         hex "Linux Link Address"
         default "0x80000000"
@@ -266,14 +262,6 @@ config LINUX_LINK_BASE
           Linux needs to be scooted a bit.
           If you don't know what the above means, leave this setting alone.
 
-config ARC_PLAT_SDRAM_SIZE
-        hex "SD RAM Size"
-        default "0x10000000"
-        help
-          Implies the amount of SDRAM/DRAM Linux is going to claim/own.
-          The actual memory itself could be larger than this number. But for
-          all software purposes, this is the amt of memory.
-
 endmenu # "Platform Board Configuration"
 
 config ARC_STACK_NONEXEC
diff --git a/arch/arc/boot/dts/skeleton.dtsi b/arch/arc/boot/dts/skeleton.dtsi
index 9b357d802a10..eb8b77367352 100644
--- a/arch/arc/boot/dts/skeleton.dtsi
+++ b/arch/arc/boot/dts/skeleton.dtsi
@@ -13,9 +13,13 @@
 
 / {
         compatible = "snps,arc";
+        clock-frequency = <80000000>;   /* 80 MHZ */
         #address-cells = <1>;
         #size-cells = <1>;
         chosen { };
         aliases { };
-        memory { device_type = "memory"; reg = <0 0>; };
+        memory {
+                device_type = "memory";
+                reg = <0x00000000 0x10000000>;  /* 256M */
+        };
 };
diff --git a/arch/arc/include/asm/clk.h b/arch/arc/include/asm/clk.h
index 61956436c75c..bf9d29f5bd53 100644
--- a/arch/arc/include/asm/clk.h
+++ b/arch/arc/include/asm/clk.h
@@ -17,4 +17,6 @@ static inline unsigned long arc_get_core_freq(void)
         return core_freq;
 }
 
+extern int arc_set_core_freq(unsigned long);
+
 #endif
diff --git a/arch/arc/kernel/clk.c b/arch/arc/kernel/clk.c
index 64925db9eb5e..66ce0dc917fb 100644
--- a/arch/arc/kernel/clk.c
+++ b/arch/arc/kernel/clk.c
@@ -8,4 +8,14 @@
 
 #include <asm/clk.h>
 
-unsigned long core_freq = CONFIG_ARC_PLAT_CLK;
+unsigned long core_freq = 800000000;
+
+/*
+ * As of now we default to device-tree provided clock
+ * In future we can determine this in early boot
+ */
+int arc_set_core_freq(unsigned long freq)
+{
+        core_freq = freq;
+        return 0;
+}
diff --git a/arch/arc/kernel/devtree.c b/arch/arc/kernel/devtree.c
index 48e157efad15..c8166dc02c38 100644
--- a/arch/arc/kernel/devtree.c
+++ b/arch/arc/kernel/devtree.c
@@ -15,6 +15,7 @@
 #include <linux/of.h>
 #include <linux/of_fdt.h>
 #include <asm/prom.h>
+#include <asm/clk.h>
 
 /* called from unflatten_device_tree() to bootstrap devicetree itself */
 void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align)
@@ -34,7 +35,9 @@ int __init setup_machine_fdt(void *dt)
         struct boot_param_header *devtree = dt;
         unsigned long dt_root;
         char *model, *compat;
+        void *clk;
         char manufacturer[16];
+        unsigned long len;
 
         /* check device tree validity */
         if (be32_to_cpu(devtree->magic) != OF_DT_HEADER)
@@ -60,5 +63,15 @@ int __init setup_machine_fdt(void *dt)
         /* Retrieve various information from the /chosen node */
         of_scan_flat_dt(early_init_dt_scan_chosen, boot_command_line);
 
+        /* Initialize {size,address}-cells info */
+        of_scan_flat_dt(early_init_dt_scan_root, NULL);
+
+        /* Setup memory, calling early_init_dt_add_memory_arch */
+        of_scan_flat_dt(early_init_dt_scan_memory, NULL);
+
+        clk = of_get_flat_dt_prop(dt_root, "clock-frequency", &len);
+        if (clk)
+                arc_set_core_freq(of_read_ulong(clk, len/4));
+
         return 0;
 }
diff --git a/arch/arc/mm/init.c b/arch/arc/mm/init.c
index 682cf5740483..caf797de23fc 100644
--- a/arch/arc/mm/init.c
+++ b/arch/arc/mm/init.c
@@ -25,7 +25,7 @@ char empty_zero_page[PAGE_SIZE] __aligned(PAGE_SIZE);
 EXPORT_SYMBOL(empty_zero_page);
 
 /* Default tot mem from .config */
-static unsigned long arc_mem_sz = CONFIG_ARC_PLAT_SDRAM_SIZE;
+static unsigned long arc_mem_sz = 0x20000000;  /* some default */
 
 /* User can over-ride above with "mem=nnn[KkMm]" in cmdline */
 static int __init setup_mem_sz(char *str)
@@ -41,7 +41,8 @@ early_param("mem", setup_mem_sz);
 
 void __init early_init_dt_add_memory_arch(u64 base, u64 size)
 {
-        pr_err("%s(%llx, %llx)\n", __func__, base, size);
+        arc_mem_sz = size & PAGE_MASK;
+        pr_info("Memory size set via devicetree %ldM\n", TO_MB(arc_mem_sz));
 }
 
 /*
@@ -62,7 +63,9 @@ void __init setup_arch_memory(void)
 
         /*
          * We do it here, so that memory is correctly instantiated
-         * even if "mem=xxx" cmline over-ride is not given
+         * even if "mem=xxx" cmline over-ride is given and/or
+         * DT has memory node. Each causes an update to @arc_mem_sz
+         * and we finally add memory one here
          */
         memblock_add(CONFIG_LINUX_LINK_BASE, arc_mem_sz);