From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paul Walmsley Subject: [PATCH v3 2/3] dt-bindings: clk: add documentation for the SiFive PRCI driver Date: Thu, 11 Apr 2019 01:27:34 -0700 Message-ID: <20190411082733.3736-3-paul.walmsley@sifive.com> References: <20190411082733.3736-2-paul.walmsley@sifive.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20190411082733.3736-2-paul.walmsley@sifive.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-riscv" Errors-To: linux-riscv-bounces+glpr-linux-riscv=m.gmane.org@lists.infradead.org To: linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, linux-clk@vger.kernel.org, devicetree@vger.kernel.org Cc: Mark Rutland , Paul Walmsley , Stephen Boyd , Megan Wachs , Michael Turquette , Palmer Dabbelt , Rob Herring , Paul Walmsley List-Id: devicetree@vger.kernel.org Add DT binding documentation for the Linux driver for the SiFive PRCI clock & reset control IP block, as found on the SiFive FU540 chip. This version includes changes requested by Stephen Boyd and Rob Herring , and fixes some errors in the initial version. Signed-off-by: Paul Walmsley Signed-off-by: Paul Walmsley Cc: Michael Turquette Cc: Stephen Boyd Cc: Rob Herring Cc: Mark Rutland Cc: Palmer Dabbelt Cc: Megan Wachs Cc: linux-clk@vger.kernel.org Cc: devicetree@vger.kernel.org Cc: linux-riscv@lists.infradead.org Cc: linux-kernel@vger.kernel.org --- .../bindings/clock/sifive/fu540-prci.txt | 46 +++++++++++++++++++ 1 file changed, 46 insertions(+) create mode 100644 Documentation/devicetree/bindings/clock/sifive/fu540-prci.txt diff --git a/Documentation/devicetree/bindings/clock/sifive/fu540-prci.txt b/Documentation/devicetree/bindings/clock/sifive/fu540-prci.txt new file mode 100644 index 000000000000..349808f4fb8c --- /dev/null +++ b/Documentation/devicetree/bindings/clock/sifive/fu540-prci.txt @@ -0,0 +1,46 @@ +SiFive FU540 PRCI bindings + +On the FU540 family of SoCs, most system-wide clock and reset integration +is via the PRCI IP block. + +Required properties: +- compatible: Should be "sifive,-prci". Only one value is + supported: "sifive,fu540-c000-prci" +- reg: Should describe the PRCI's register target physical address region +- clocks: Should point to the hfclk device tree node and the rtcclk + device tree node. The RTC clock here is not a time-of-day clock, + but is instead a high-stability clock source for system timers + and cycle counters. +- #clock-cells: Should be <1> + +The clock consumer should specify the desired clock via the clock ID +macros defined in include/dt-bindings/clock/sifive-fu540-prci.h. +These macros begin with PRCI_CLK_. + +The hfclk and rtcclk nodes are required, and represent physical +crystals or resonators located on the PCB. These nodes should be present +underneath /, rather than /soc. + +Examples: + +/* under /, in PCB-specific DT data */ +hfclk: hfclk { + #clock-cells = <0>; + compatible = "fixed-clock"; + clock-frequency = <33333333>; + clock-output-names = "hfclk"; +}; +rtcclk: rtcclk { + #clock-cells = <0>; + compatible = "fixed-clock"; + clock-frequency = <1000000>; + clock-output-names = "rtcclk"; +}; + +/* under /soc, in SoC-specific DT data */ +prci: clock-controller@10000000 { + compatible = "sifive,fu540-c000-prci"; + reg = <0x0 0x10000000 0x0 0x1000>; + clocks = <&hfclk>, <&rtcclk>; + #clock-cells = <1>; +}; -- 2.20.1