[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <1433966978-24422-2-git-send-email-daniel.thompson@linaro.org>
Date: Wed, 10 Jun 2015 21:09:36 +0100
From: Daniel Thompson <daniel.thompson@...aro.org>
To: Mike Turquette <mturquette@...aro.org>,
Stephen Boyd <sboyd@...eaurora.org>
Cc: Daniel Thompson <daniel.thompson@...aro.org>,
Rob Herring <robh+dt@...nel.org>,
Pawel Moll <pawel.moll@....com>,
Mark Rutland <mark.rutland@....com>,
Ian Campbell <ijc+devicetree@...lion.org.uk>,
Kumar Gala <galak@...eaurora.org>,
Russell King <linux@....linux.org.uk>,
Maxime Coquelin <mcoquelin.stm32@...il.com>,
Kamil Lulko <rev13@...pl>, Andreas Farber <afaerber@...e.de>,
linux-clk@...r.kernel.org, devicetree@...r.kernel.org,
linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
patches@...aro.org, linaro-kernel@...ts.linaro.org
Subject: [PATCH v3 1/3] dt-bindings: Document the STM32F4 clock bindings
This adds documentation of device tree bindings for the clock related
portions of the STM32 RCC block.
Signed-off-by: Daniel Thompson <daniel.thompson@...aro.org>
---
.../devicetree/bindings/clock/st,stm32-rcc.txt | 65 ++++++++++++++++++++++
1 file changed, 65 insertions(+)
create mode 100644 Documentation/devicetree/bindings/clock/st,stm32-rcc.txt
diff --git a/Documentation/devicetree/bindings/clock/st,stm32-rcc.txt b/Documentation/devicetree/bindings/clock/st,stm32-rcc.txt
new file mode 100644
index 0000000..fee3205
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/st,stm32-rcc.txt
@@ -0,0 +1,65 @@
+STMicroelectronics STM32 Reset and Clock Controller
+===================================================
+
+The RCC IP is both a reset and a clock controller. This documentation only
+describes the clock part.
+
+Please also refer to clock-bindings.txt in this directory for common clock
+controller binding usage.
+
+Required properties:
+- compatible: Should be "st,stm32f42xx-rcc"
+- reg: should be register base and length as documented in the
+ datasheet
+- #clock-cells: 2, device nodes should specify the clock in their "clocks"
+ property, containing a phandle to the clock device node, an index selecting
+ between gated clocks and other clocks and an index specifying the clock to
+ use.
+
+Example:
+
+ rcc: rcc@...23800 {
+ #clock-cells = <2>
+ compatible = "st,stm32f42xx-rcc", "st,stm32-rcc";
+ reg = <0x40023800 0x400>;
+ };
+
+Specifying gated clocks
+=======================
+
+The primary index must be set to 0.
+
+The secondary index is the bit number within the RCC register bank, starting
+from the first RCC clock enable register (RCC_AHB1ENR, address offset 0x30).
+
+It is calculated as: index = register_offset / 4 * 32 + bit_offset.
+Where bit_offset is the bit offset within the register (LSB is 0, MSB is 31).
+
+Example:
+
+ /* Gated clock, AHB1 bit 0 (GPIOA) */
+ ... {
+ clocks = <&rcc 0 0>
+ };
+
+ /* Gated clock, AHB2 bit 4 (CRYP) */
+ ... {
+ clocks = <&rcc 0 36>
+ };
+
+Specifying other clocks
+=======================
+
+The primary index must be set to 1.
+
+The secondary index is bound with the following magic numbers:
+
+ 0 SYSTICK
+ 1 FCLK
+
+Example:
+
+ /* Misc clock, FCLK */
+ ... {
+ clocks = <&rcc 1 1>
+ };
--
2.4.2
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists