summaryrefslogtreecommitdiff
path: root/Documentation/devicetree
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2012-07-25 03:40:57 +0400
committerLinus Torvalds <torvalds@linux-foundation.org>2012-07-25 03:40:57 +0400
commit9161c3b796a2841a9a7be3d9c9dd121269ce90e8 (patch)
tree4920a191c4a2eecae1a4e055af7e967f1e769714 /Documentation/devicetree
parent97027da6adf2e24a4e8d3d9c0668da3006b29971 (diff)
parent137f8a7213d80c1388ca48280c1ef0856b6fec30 (diff)
downloadlinux-9161c3b796a2841a9a7be3d9c9dd121269ce90e8.tar.xz
Merge tag 'clk-for-linus' of git://git.linaro.org/people/mturquette/linux
Pull common clk framework changes from Michael Turquette: "This includes a small number of core framework improvments, platform ports and new DT bindings." Fix up trivial conflicts in drivers/clk/Makefile * tag 'clk-for-linus' of git://git.linaro.org/people/mturquette/linux: (21 commits) clk: fix compile for OF && !COMMON_CLK clk: fix clk_get on of_clk_get_by_name return check clk: mxs: clk_register_clkdev mx28 usb clocks clk: add highbank clock support dt: add clock binding doc to primecell bindings clk: add DT fixed-clock binding support clk: add DT clock binding support ARM: integrator: convert to common clock clk: add versatile ICST307 driver ARM: integrator: put symbolic bus names on devices ARM: u300: convert to common clock clk: cache parent clocks only for muxes clk: wm831x: Add initial WM831x clock driver clk: Constify struct clk_init_data clk: Add CLK_IS_BASIC flag to identify basic clocks clk: Add support for rate table based dividers clk: Add support for power of two type dividers clk: mxs: imx28: decrease the frequency of ref_io1 for SSP2 and SSP3 clk: mxs: add clkdev lookup for pwm clk: mxs: Fix the GPMI clock name ...
Diffstat (limited to 'Documentation/devicetree')
-rw-r--r--Documentation/devicetree/bindings/arm/primecell.txt6
-rw-r--r--Documentation/devicetree/bindings/clock/calxeda.txt17
-rw-r--r--Documentation/devicetree/bindings/clock/clock-bindings.txt117
-rw-r--r--Documentation/devicetree/bindings/clock/fixed-clock.txt21
4 files changed, 161 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/arm/primecell.txt b/Documentation/devicetree/bindings/arm/primecell.txt
index 951ca46789d4..64fc82bc8928 100644
--- a/Documentation/devicetree/bindings/arm/primecell.txt
+++ b/Documentation/devicetree/bindings/arm/primecell.txt
@@ -13,11 +13,17 @@ Required properties:
Optional properties:
- arm,primecell-periphid : Value to override the h/w value with
+- clocks : From common clock binding. First clock is phandle to clock for apb
+ pclk. Additional clocks are optional and specific to those peripherals.
+- clock-names : From common clock binding. Shall be "apb_pclk" for first clock.
Example:
serial@fff36000 {
compatible = "arm,pl011", "arm,primecell";
arm,primecell-periphid = <0x00341011>;
+ clocks = <&pclk>;
+ clock-names = "apb_pclk";
+
};
diff --git a/Documentation/devicetree/bindings/clock/calxeda.txt b/Documentation/devicetree/bindings/clock/calxeda.txt
new file mode 100644
index 000000000000..0a6ac1bdcda1
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/calxeda.txt
@@ -0,0 +1,17 @@
+Device Tree Clock bindings for Calxeda highbank platform
+
+This binding uses the common clock binding[1].
+
+[1] Documentation/devicetree/bindings/clock/clock-bindings.txt
+
+Required properties:
+- compatible : shall be one of the following:
+ "calxeda,hb-pll-clock" - for a PLL clock
+ "calxeda,hb-a9periph-clock" - The A9 peripheral clock divided from the
+ A9 clock.
+ "calxeda,hb-a9bus-clock" - The A9 bus clock divided from the A9 clock.
+ "calxeda,hb-emmc-clock" - Divided clock for MMC/SD controller.
+- reg : shall be the control register offset from SYSREGs base for the clock.
+- clocks : shall be the input parent clock phandle for the clock. This is
+ either an oscillator or a pll output.
+- #clock-cells : from common clock binding; shall be set to 0.
diff --git a/Documentation/devicetree/bindings/clock/clock-bindings.txt b/Documentation/devicetree/bindings/clock/clock-bindings.txt
new file mode 100644
index 000000000000..eb65d417f8c4
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/clock-bindings.txt
@@ -0,0 +1,117 @@
+This binding is a work-in-progress, and are based on some experimental
+work by benh[1].
+
+Sources of clock signal can be represented by any node in the device
+tree. Those nodes are designated as clock providers. Clock consumer
+nodes use a phandle and clock specifier pair to connect clock provider
+outputs to clock inputs. Similar to the gpio specifiers, a clock
+specifier is an array of one more more cells identifying the clock
+output on a device. The length of a clock specifier is defined by the
+value of a #clock-cells property in the clock provider node.
+
+[1] http://patchwork.ozlabs.org/patch/31551/
+
+==Clock providers==
+
+Required properties:
+#clock-cells: Number of cells in a clock specifier; Typically 0 for nodes
+ with a single clock output and 1 for nodes with multiple
+ clock outputs.
+
+Optional properties:
+clock-output-names: Recommended to be a list of strings of clock output signal
+ names indexed by the first cell in the clock specifier.
+ However, the meaning of clock-output-names is domain
+ specific to the clock provider, and is only provided to
+ encourage using the same meaning for the majority of clock
+ providers. This format may not work for clock providers
+ using a complex clock specifier format. In those cases it
+ is recommended to omit this property and create a binding
+ specific names property.
+
+ Clock consumer nodes must never directly reference
+ the provider's clock-output-names property.
+
+For example:
+
+ oscillator {
+ #clock-cells = <1>;
+ clock-output-names = "ckil", "ckih";
+ };
+
+- this node defines a device with two clock outputs, the first named
+ "ckil" and the second named "ckih". Consumer nodes always reference
+ clocks by index. The names should reflect the clock output signal
+ names for the device.
+
+==Clock consumers==
+
+Required properties:
+clocks: List of phandle and clock specifier pairs, one pair
+ for each clock input to the device. Note: if the
+ clock provider specifies '0' for #clock-cells, then
+ only the phandle portion of the pair will appear.
+
+Optional properties:
+clock-names: List of clock input name strings sorted in the same
+ order as the clocks property. Consumers drivers
+ will use clock-names to match clock input names
+ with clocks specifiers.
+clock-ranges: Empty property indicating that child nodes can inherit named
+ clocks from this node. Useful for bus nodes to provide a
+ clock to their children.
+
+For example:
+
+ device {
+ clocks = <&osc 1>, <&ref 0>;
+ clock-names = "baud", "register";
+ };
+
+
+This represents a device with two clock inputs, named "baud" and "register".
+The baud clock is connected to output 1 of the &osc device, and the register
+clock is connected to output 0 of the &ref.
+
+==Example==
+
+ /* external oscillator */
+ osc: oscillator {
+ compatible = "fixed-clock";
+ #clock-cells = <1>;
+ clock-frequency = <32678>;
+ clock-output-names = "osc";
+ };
+
+ /* phase-locked-loop device, generates a higher frequency clock
+ * from the external oscillator reference */
+ pll: pll@4c000 {
+ compatible = "vendor,some-pll-interface"
+ #clock-cells = <1>;
+ clocks = <&osc 0>;
+ clock-names = "ref";
+ reg = <0x4c000 0x1000>;
+ clock-output-names = "pll", "pll-switched";
+ };
+
+ /* UART, using the low frequency oscillator for the baud clock,
+ * and the high frequency switched PLL output for register
+ * clocking */
+ uart@a000 {
+ compatible = "fsl,imx-uart";
+ reg = <0xa000 0x1000>;
+ interrupts = <33>;
+ clocks = <&osc 0>, <&pll 1>;
+ clock-names = "baud", "register";
+ };
+
+This DT fragment defines three devices: an external oscillator to provide a
+low-frequency reference clock, a PLL device to generate a higher frequency
+clock signal, and a UART.
+
+* The oscillator is fixed-frequency, and provides one clock output, named "osc".
+* The PLL is both a clock provider and a clock consumer. It uses the clock
+ signal generated by the external oscillator, and provides two output signals
+ ("pll" and "pll-switched").
+* The UART has its baud clock connected the external oscillator and its
+ register clock connected to the PLL clock (the "pll-switched" signal)
diff --git a/Documentation/devicetree/bindings/clock/fixed-clock.txt b/Documentation/devicetree/bindings/clock/fixed-clock.txt
new file mode 100644
index 000000000000..0b1fe7824093
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/fixed-clock.txt
@@ -0,0 +1,21 @@
+Binding for simple fixed-rate clock sources.
+
+This binding uses the common clock binding[1].
+
+[1] Documentation/devicetree/bindings/clock/clock-bindings.txt
+
+Required properties:
+- compatible : shall be "fixed-clock".
+- #clock-cells : from common clock binding; shall be set to 0.
+- clock-frequency : frequency of clock in Hz. Should be a single cell.
+
+Optional properties:
+- gpios : From common gpio binding; gpio connection to clock enable pin.
+- clock-output-names : From common clock binding.
+
+Example:
+ clock {
+ compatible = "fixed-clock";
+ #clock-cells = <0>;
+ clock-frequency = <1000000000>;
+ };