openwrtv4/target/linux/ramips/patches-3.8/0207-owrt-MIPS-ralink-add-support-for-runtime-memory-dete.patch

From bcd97dbdcb7bc0300397db481872252e8849307b Mon Sep 17 00:00:00 2001
From: John Crispin <blogic@openwrt.org>
Date: Mon, 25 Mar 2013 10:50:53 +0100
Subject: [PATCH 207/208] owrt: MIPS: ralink: add support for runtime memory
 detection

This allows us to add a device_node called "memorydetect" to the DT with
information about the memory windoe of the SoC. Based on this the memory is
detected ar runtime.

Signed-off-by: John Crispin <blogic@openwrt.org>
---
 arch/mips/include/asm/prom.h |    3 ++
 arch/mips/kernel/prom.c      |    3 ++
 arch/mips/ralink/Makefile    |    2 +-
 arch/mips/ralink/memory.c    |  119 ++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 126 insertions(+), 1 deletion(-)
 create mode 100644 arch/mips/ralink/memory.c

--- a/arch/mips/include/asm/prom.h
+++ b/arch/mips/include/asm/prom.h
@@ -20,6 +20,9 @@
 extern int early_init_dt_scan_memory_arch(unsigned long node,
 	const char *uname, int depth, void *data);
 
+extern int early_init_dt_detect_memory(unsigned long node,
+	const char *uname, int depth, void *data);
+
 extern void device_tree_init(void);
 
 static inline unsigned long pci_address_to_pio(phys_addr_t address)
--- a/arch/mips/kernel/prom.c
+++ b/arch/mips/kernel/prom.c
@@ -88,6 +88,9 @@ void __init early_init_devtree(void *par
 	of_scan_flat_dt(early_init_dt_scan_memory_arch, NULL);
 
 	/* try to load the mips machine name */
+	of_scan_flat_dt(early_init_dt_detect_memory, NULL);
+
+	/* try to load the mips machine name */
 	of_scan_flat_dt(early_init_dt_scan_model, NULL);
 }
 
--- a/arch/mips/ralink/Makefile
+++ b/arch/mips/ralink/Makefile
@@ -6,7 +6,7 @@
 # Copyright (C) 2009-2011 Gabor Juhos <juhosg@openwrt.org>
 # Copyright (C) 2013 John Crispin <blogic@openwrt.org>
 
-obj-y := prom.o of.o reset.o clk.o irq.o pinmux.o timer.o
+obj-y := prom.o of.o reset.o clk.o irq.o pinmux.o timer.o memory.o
 
 obj-$(CONFIG_SOC_RT288X) += rt288x.o
 obj-$(CONFIG_SOC_RT305X) += rt305x.o rt305x-usb.o
--- /dev/null
+++ b/arch/mips/ralink/memory.c
@@ -0,0 +1,119 @@
+/*
+ *  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.
+ *
+ *  Copyright (C) 2009 Gabor Juhos <juhosg@openwrt.org>
+ *  Copyright (C) 2013 John Crispin <blogic@openwrt.org>
+ */
+
+#include <linux/string.h>
+#include <linux/of_fdt.h>
+#include <linux/of_platform.h>
+
+#include <asm/bootinfo.h>
+#include <asm/addrspace.h>
+
+#include "common.h"
+
+#define MB	(1024 * 1024)
+
+unsigned long ramips_mem_base;
+unsigned long ramips_mem_size_min;
+unsigned long ramips_mem_size_max;
+
+#ifdef CONFIG_SOC_RT305X
+
+#include <asm/mach-ralink/rt305x.h>
+
+static unsigned long rt5350_get_mem_size(void)
+{
+	void __iomem *sysc = (void __iomem *) KSEG1ADDR(RT305X_SYSC_BASE);
+	unsigned long ret;
+	u32 t;
+
+	t = __raw_readl(sysc + SYSC_REG_SYSTEM_CONFIG);
+	t = (t >> RT5350_SYSCFG0_DRAM_SIZE_SHIFT) &
+	RT5350_SYSCFG0_DRAM_SIZE_MASK;
+
+	switch (t) {
+	case RT5350_SYSCFG0_DRAM_SIZE_2M:
+		ret = 2 * 1024 * 1024;
+		break;
+	case RT5350_SYSCFG0_DRAM_SIZE_8M:
+		ret = 8 * 1024 * 1024;
+		break;
+	case RT5350_SYSCFG0_DRAM_SIZE_16M:
+		ret = 16 * 1024 * 1024;
+		break;
+	case RT5350_SYSCFG0_DRAM_SIZE_32M:
+		ret = 32 * 1024 * 1024;
+		break;
+	case RT5350_SYSCFG0_DRAM_SIZE_64M:
+		ret = 64 * 1024 * 1024;
+		break;
+	default:
+		panic("rt5350: invalid DRAM size: %u", t);
+		break;
+	}
+
+	return ret;
+}
+
+#endif
+
+static void __init detect_mem_size(void)
+{
+	unsigned long size;
+
+#ifdef CONFIG_SOC_RT305X
+	if (soc_is_rt5350()) {
+		size = rt5350_get_mem_size();
+	} else
+#endif
+	{
+		void *base;
+
+		base = (void *) KSEG1ADDR(detect_mem_size);
+		for (size = ramips_mem_size_min; size < ramips_mem_size_max;
+		     size <<= 1 ) {
+			if (!memcmp(base, base + size, 1024))
+				break;
+		}
+	}
+
+	pr_info("memory detected: %uMB\n", (unsigned int) size / MB);
+
+	add_memory_region(ramips_mem_base, size, BOOT_MEM_RAM);
+}
+
+int __init early_init_dt_detect_memory(unsigned long node, const char *uname,
+				     int depth, void *data)
+{
+	unsigned long l;
+	__be32 *mem;
+
+	/* We are scanning "memorydetect" nodes only */
+	if (depth != 1 || strcmp(uname, "memorydetect") != 0)
+		return 0;
+
+	mem = of_get_flat_dt_prop(node, "ralink,memory", &l);
+	if (mem == NULL)
+		return 0;
+
+	if ((l / sizeof(__be32)) != 3)
+		panic("invalid memorydetect node\n");
+
+	ramips_mem_base = dt_mem_next_cell(dt_root_addr_cells, &mem);
+	ramips_mem_size_min = dt_mem_next_cell(dt_root_size_cells, &mem);
+	ramips_mem_size_max = dt_mem_next_cell(dt_root_size_cells, &mem);
+
+	pr_info("memory window: 0x%llx, min: %uMB, max: %uMB\n",
+		(unsigned long long) ramips_mem_base,
+		(unsigned int) ramips_mem_size_min / MB,
+		(unsigned int) ramips_mem_size_max / MB);
+
+	detect_mem_size();
+
+	return 0;
+}