From patchwork Fri Mar 17 09:09:33 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tero Kristo X-Patchwork-Id: 9630035 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 8ADAB60249 for ; Fri, 17 Mar 2017 09:11:44 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6ABE627FB1 for ; Fri, 17 Mar 2017 09:11:44 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 5EDDE285E3; Fri, 17 Mar 2017 09:11:44 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI,T_DKIM_INVALID autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B5D5627FB1 for ; Fri, 17 Mar 2017 09:11:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751064AbdCQJLn (ORCPT ); Fri, 17 Mar 2017 05:11:43 -0400 Received: from fllnx210.ext.ti.com ([198.47.19.17]:30920 "EHLO fllnx210.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751004AbdCQJLm (ORCPT ); Fri, 17 Mar 2017 05:11:42 -0400 Received: from dlelxv90.itg.ti.com ([172.17.2.17]) by fllnx210.ext.ti.com (8.15.1/8.15.1) with ESMTP id v2H99xBK021237; Fri, 17 Mar 2017 04:10:00 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ti.com; s=ti-com-17Q1; t=1489741800; bh=NrEPRIoKSpDtmXvJIdbRuUvQz8qHVA04nSjFwmlW3C0=; h=From:To:CC:Subject:Date:In-Reply-To:References; b=LbRFOjJ4+FoBk0emaQ3NDk2tkCzaPc8LJd9XwccC5AoHf1xrJeZEk7clmP5Pk/s17 g9mSqfV9QvQLftOHAG9FLOw0zb+rjItjIXXdM4KtrN2r9LWa+JPpNfy1ChuVgfAT/l ZKYh4V+EzalzaHGSrqW/7yLGAWsz+PQWmFq0+01U= Received: from DFLE73.ent.ti.com (dfle73.ent.ti.com [128.247.5.110]) by dlelxv90.itg.ti.com (8.14.3/8.13.8) with ESMTP id v2H99xx3005760; Fri, 17 Mar 2017 04:09:59 -0500 Received: from dflp32.itg.ti.com (10.64.6.15) by DFLE73.ent.ti.com (128.247.5.110) with Microsoft SMTP Server id 14.3.294.0; Fri, 17 Mar 2017 04:09:58 -0500 Received: from gomoku.home (ileax41-snat.itg.ti.com [10.172.224.153]) by dflp32.itg.ti.com (8.14.3/8.13.8) with ESMTP id v2H99p3t016945; Fri, 17 Mar 2017 04:09:54 -0500 From: Tero Kristo To: , , , , CC: , Paul Walmsley Subject: [PATCHv2 1/9] Documentation: dt-bindings: Add binding documentation for TI clkctrl clocks Date: Fri, 17 Mar 2017 11:09:33 +0200 Message-ID: <1489741781-12816-2-git-send-email-t-kristo@ti.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1489741781-12816-1-git-send-email-t-kristo@ti.com> References: <1489741781-12816-1-git-send-email-t-kristo@ti.com> MIME-Version: 1.0 Sender: linux-clk-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-clk@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Tony Lindgren Texas Instruments omap variant SoCs starting with omap4 have a clkctrl clock controller instance for each interconnect target module. The clkctrl controls functional and interface clocks for the module. The clkctrl clocks are currently handled by arch/arm/mach-omap2 hwmod code. With this binding and a related clock device driver we can start moving the clkctrl clock handling to live in drivers/clk/ti. Note that this binding allows keeping the clockdomain related parts out of drivers/clock. The CLKCTCTRL and DYNAMICDEP registers can be handled by a separate driver in drivers/soc/ti and genpd. If the clockdomain driver needs to know it's clocks, we can just set the the clkctrl device instances to be children of the related clockdomain device. Each clkctrl clock can have multiple optional gate clocks, and multiple optional mux clocks. To represent this in device tree, it seems that it is best done using four clock cells #clock-cells = <2> property. The reasons for using #clock-cells = <2> are: 1. We need to specify the clkctrl offset from the instance base. Otherwise we end up with a large number of device tree nodes that need to be patched when new clocks are discovered in a clkctrl clock with minor hardware revision changes for example 2. On omap5 CM_L3INIT_USB_HOST_HS_CLKCTRL has ten OPTFCLKEN bits. So we need to use a separate cell for optional gate clocks to avoid address space conflicts There is probably no need to list input clocks for each clkctrl clock instance in the binding. If we want to add them, the standard clocks binding can be used for that. For hardware reference, see omap4430 TRM "Table 3-1312. L4PER_CM2 Registers Mapping Summary" for example. It shows one instance of a clkctrl clock controller with multiple clkctrl registers. Cc: Paul Walmsley Acked-by: Rob Herring Signed-off-by: Tony Lindgren Signed-off-by: Tero Kristo --- .../devicetree/bindings/clock/ti-clkctrl.txt | 56 ++++++++++++++++++++++ 1 file changed, 56 insertions(+) create mode 100644 Documentation/devicetree/bindings/clock/ti-clkctrl.txt diff --git a/Documentation/devicetree/bindings/clock/ti-clkctrl.txt b/Documentation/devicetree/bindings/clock/ti-clkctrl.txt new file mode 100644 index 0000000..7e5d9f5 --- /dev/null +++ b/Documentation/devicetree/bindings/clock/ti-clkctrl.txt @@ -0,0 +1,56 @@ +Texas Instruments clkctrl clock binding + +Texas Instruments SoCs can have a clkctrl clock controller for each +interconnect target module. The clkctrl clock controller manages functional +and interface clocks for each module. Each clkctrl controller can also +gate one or more optional functional clocks for a module, and can have one +or more clock muxes. There is a clkctrl clock controller typically for each +interconnect target module on omap4 and later variants. + +The clock consumers can specify the index of the clkctrl clock using +the hardware offset from the clkctrl instance register space. The optional +clocks can be specified by clkctrl hardware offset and the index of the +optional clock. + +For more information, please see the Linux clock framework binding at +Documentation/devicetree/bindings/clock/clock-bindings.txt. + +Required properties : +- compatible : shall be "ti,clkctrl" +- #clock-cells : shall contain 2 with the first entry being the instance + offset from the clock domain base and the second being the + clock index + +Example: Clock controller node on omap 4430: + +&cm2 { + l4per: cm@1400 { + cm_l4per@0 { + cm_l4per_clkctrl: clk@20 { + compatible = "ti,clkctrl"; + reg = <0x20 0x1b0>; + #clock-cells = <4>; + }; + }; + }; +}; + +Example: Preprocessor helper macros in dt-bindings/clock/ti-clkctrl.h + +#define OMAP4_CLKCTRL_OFFSET 0x20 +#define OMAP4_CLKCTRL_INDEX(offset) ((offset) - OMAP4_CLKCTRL_OFFSET) +#define MODULEMODE_HWCTRL 1 +#define MODULEMODE_SWCTRL 2 + +#define OMAP4_GPTIMER10_CLKTRL OMAP4_CLKCTRL_INDEX(0x28) +#define OMAP4_GPTIMER11_CLKTRL OMAP4_CLKCTRL_INDEX(0x30) +#define OMAP4_GPTIMER2_CLKTRL OMAP4_CLKCTRL_INDEX(0x38) +... +#define OMAP4_GPIO2_CLKCTRL OMAP_CLKCTRL_INDEX(0x60) + +Example: Clock consumer node for GPIO2: + +&gpio2 { + clocks = <&cm_l4per_clkctrl OMAP4_GPIO2_CLKCTRL 0 + &cm_l4per_clkctrl OMAP4_GPIO2_CLKCTRL 8>; +};