Hi,
On 24-03-15 16:19, Maxime Ripard wrote:
Hi,
On Fri, Mar 20, 2015 at 07:52:45PM +0100, Hans de Goede wrote:
From: Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx>
The Allwinner SoCs have a handful of SRAM that can be either mapped to be
accessible by devices or the CPU.
That mapping is controlled by an SRAM controller, and that mapping might not be
set by the bootloader, for example if the device wasn't used at all, or if
we're using solutions like the U-Boot's Falcon Boot.
We could also imagine changing this at runtime for example to change the
mapping of these SRAMs to use them for suspend/resume or runtime memory rate
change, if that ever happens.
These use cases require some API in the kernel to control that mapping,
exported through a drivers/soc driver.
This driver also implement a debugfs file that shows the SRAM found in the
system, the current mapping and the SRAM that have been claimed by some drivers
in the kernel.
Signed-off-by: Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx>
[hdegoede@xxxxxxxxxx: Changed compat string to sun4i-a10-sram-controller, as
the sram controller is identical on sun4i, sun5i & sun7i, added devicetree
binding documentation, fixed some checkpatch warnings]
Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
---
.../devicetree/bindings/soc/sunxi/sram.txt | 64 ++++++
drivers/soc/Kconfig | 1 +
drivers/soc/Makefile | 1 +
drivers/soc/sunxi/Kconfig | 12 ++
drivers/soc/sunxi/Makefile | 1 +
drivers/soc/sunxi/sunxi_sram.c | 235 +++++++++++++++++++++
include/linux/soc/sunxi/sunxi_sram.h | 24 +++
7 files changed, 338 insertions(+)
create mode 100644 Documentation/devicetree/bindings/soc/sunxi/sram.txt
create mode 100644 drivers/soc/sunxi/Kconfig
create mode 100644 drivers/soc/sunxi/Makefile
create mode 100644 drivers/soc/sunxi/sunxi_sram.c
create mode 100644 include/linux/soc/sunxi/sunxi_sram.h
diff --git a/Documentation/devicetree/bindings/soc/sunxi/sram.txt b/Documentation/devicetree/bindings/soc/sunxi/sram.txt
new file mode 100644
index 0000000..6e1bc80
--- /dev/null
+++ b/Documentation/devicetree/bindings/soc/sunxi/sram.txt
@@ -0,0 +1,64 @@
+Allwinnner sun4i / sun5i / sun7i SoC SRAM controllers
+-----------------------------------------------------
+
+Required properties:
+- compatible : "allwinner,sun4i-a10-sram-controller"
+- reg : sram controller register offset + length
+
+SRAM nodes
+----------
+
+Besides a node for the SRAM controller the devicetree must also contain a
+node for each SRAM block controlled by the controller.
+
+Required sram node properties:
+- compatible : "allwinner,sun4i-a10-sram"
+- allwinner,sram-name : should be one of
+ * "A1"
+ * "A2"
+ * "A3-A4"
+ * "D"
+
+Example
+-------
+
+/*
+ * Note we use the address were mmio register start, not where
^ where
+ * the SRAM blocks starts, this cannot be changed because doing
^ start
+ * doing so would be a devicetree ABI change.
One doing too many ? :)
Both fixed.
+ */
+soc@01c00000 {
+ compatible = "simple-bus";
+ #address-cells = <1>;
+ #size-cells = <1>;
+ ranges;
+
+ sram@00000000 {
+ compatible = "allwinner,sun4i-a10-sram";
+ reg = <0x00000000 0x4000>;
+ allwinner,sram-name = "A1";
+ };
+
+ sram@00004000 {
+ compatible = "allwinner,sun4i-a10-sram";
+ reg = <0x00004000 0x4000>;
+ allwinner,sram-name = "A2";
+ };
+
+ sram@00008000 {
+ compatible = "allwinner,sun4i-a10-sram";
+ reg = <0x00008000 0x4000>;
+ allwinner,sram-name = "A3-A4";
+ };
+
+ sram@00010000 {
+ compatible = "allwinner,sun4i-a10-sram";
+ reg = <0x00010000 0x1000>;
+ allwinner,sram-name = "D";
+ };
+
+ sram-controller@01c00000 {
+ compatible = "allwinner,sun4i-a10-sram-controller";
+ reg = <0x01c00000 0x30>;
+ };
+};
diff --git a/drivers/soc/Kconfig b/drivers/soc/Kconfig
index 76d6bd4..5d0f55d 100644
--- a/drivers/soc/Kconfig
+++ b/drivers/soc/Kconfig
@@ -1,6 +1,7 @@
menu "SOC (System On Chip) specific Drivers"
source "drivers/soc/qcom/Kconfig"
+source "drivers/soc/sunxi/Kconfig"
source "drivers/soc/ti/Kconfig"
source "drivers/soc/versatile/Kconfig"
diff --git a/drivers/soc/Makefile b/drivers/soc/Makefile
index 063113d..170bba3 100644
--- a/drivers/soc/Makefile
+++ b/drivers/soc/Makefile
@@ -3,6 +3,7 @@
#
obj-$(CONFIG_ARCH_QCOM) += qcom/
+obj-$(CONFIG_ARCH_SUNXI) += sunxi/
obj-$(CONFIG_ARCH_TEGRA) += tegra/
obj-$(CONFIG_SOC_TI) += ti/
obj-$(CONFIG_PLAT_VERSATILE) += versatile/
diff --git a/drivers/soc/sunxi/Kconfig b/drivers/soc/sunxi/Kconfig
new file mode 100644
index 0000000..212c634
--- /dev/null
+++ b/drivers/soc/sunxi/Kconfig
@@ -0,0 +1,12 @@
+#
+# Allwinner sunXi SoC drivers
+#
+config SUNXI_SRAM
+ tristate "Allwinner sunXi SRAM Controller"
+ depends on ARCH_SUNXI
+ default y
The indentation is off.
That is because your original patch used 8 spaces instead of tabs,
fixed.
Also, that could probably be turned into an hidden option, with a
default y, so that we are sure that it's always going to be there.
Also done / fixed.
Regards,
Hans
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