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authorArnd Bergmann <arnd@arndb.de>2015-05-13 17:56:47 +0200
committerArnd Bergmann <arnd@arndb.de>2015-05-13 17:56:47 +0200
commit92d19e26d67704397b70cf5728fd77bd13b74c43 (patch)
treead1dc28de359a2004275e067158a806d4fe2b11d
parentfe7a5bfe18f06a418705098f6212bda2cbdcadb5 (diff)
parent6ea2609ab386f6bfeebc39e1418b7497a9deb55c (diff)
Merge tag 'tegra-for-4.2-ramcode' of git://git.kernel.org/pub/scm/linux/kernel/git/tegra/linux into next/drivers
Merge "ARM: tegra: RAM code access for v4.2-rc1" from Thierry Reding: The RAM code is used by the memory and external memory controllers to determine which set of timings to use for memory frequency scaling. * tag 'tegra-for-4.2-ramcode' of git://git.kernel.org/pub/scm/linux/kernel/git/tegra/linux: soc/tegra: fuse: Add RAM code reader helper of: Document long-ram-code property in nvidia,tegra20-apbmisc
-rw-r--r--Documentation/devicetree/bindings/misc/nvidia,tegra20-apbmisc.txt2
-rw-r--r--drivers/soc/tegra/fuse/tegra-apbmisc.c21
-rw-r--r--include/soc/tegra/fuse.h1
3 files changed, 24 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/misc/nvidia,tegra20-apbmisc.txt b/Documentation/devicetree/bindings/misc/nvidia,tegra20-apbmisc.txt
index 47b205cc9cc7..4556359c5876 100644
--- a/Documentation/devicetree/bindings/misc/nvidia,tegra20-apbmisc.txt
+++ b/Documentation/devicetree/bindings/misc/nvidia,tegra20-apbmisc.txt
@@ -10,3 +10,5 @@ Required properties:
The second entry gives the physical address and length of the
registers indicating the strapping options.
+Optional properties:
+- nvidia,long-ram-code: If present, the RAM code is long (4 bit). If not, short (2 bit).
diff --git a/drivers/soc/tegra/fuse/tegra-apbmisc.c b/drivers/soc/tegra/fuse/tegra-apbmisc.c
index 3bf5aba4caaa..73fad05d8f2c 100644
--- a/drivers/soc/tegra/fuse/tegra-apbmisc.c
+++ b/drivers/soc/tegra/fuse/tegra-apbmisc.c
@@ -28,8 +28,15 @@
#define APBMISC_SIZE 0x64
#define FUSE_SKU_INFO 0x10
+#define PMC_STRAPPING_OPT_A_RAM_CODE_SHIFT 4
+#define PMC_STRAPPING_OPT_A_RAM_CODE_MASK_LONG \
+ (0xf << PMC_STRAPPING_OPT_A_RAM_CODE_SHIFT)
+#define PMC_STRAPPING_OPT_A_RAM_CODE_MASK_SHORT \
+ (0x3 << PMC_STRAPPING_OPT_A_RAM_CODE_SHIFT)
+
static void __iomem *apbmisc_base;
static void __iomem *strapping_base;
+static bool long_ram_code;
u32 tegra_read_chipid(void)
{
@@ -54,6 +61,18 @@ u32 tegra_read_straps(void)
return 0;
}
+u32 tegra_read_ram_code(void)
+{
+ u32 straps = tegra_read_straps();
+
+ if (long_ram_code)
+ straps &= PMC_STRAPPING_OPT_A_RAM_CODE_MASK_LONG;
+ else
+ straps &= PMC_STRAPPING_OPT_A_RAM_CODE_MASK_SHORT;
+
+ return straps >> PMC_STRAPPING_OPT_A_RAM_CODE_SHIFT;
+}
+
static const struct of_device_id apbmisc_match[] __initconst = {
{ .compatible = "nvidia,tegra20-apbmisc", },
{},
@@ -112,4 +131,6 @@ void __init tegra_init_apbmisc(void)
strapping_base = of_iomap(np, 1);
if (!strapping_base)
pr_err("ioremap tegra strapping_base failed\n");
+
+ long_ram_code = of_property_read_bool(np, "nvidia,long-ram-code");
}
diff --git a/include/soc/tegra/fuse.h b/include/soc/tegra/fuse.h
index b5f7b5f8d008..b019e3465f11 100644
--- a/include/soc/tegra/fuse.h
+++ b/include/soc/tegra/fuse.h
@@ -56,6 +56,7 @@ struct tegra_sku_info {
};
u32 tegra_read_straps(void);
+u32 tegra_read_ram_code(void);
u32 tegra_read_chipid(void);
int tegra_fuse_readl(unsigned long offset, u32 *value);

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