From patchwork Wed May 17 15:50:06 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tero Kristo X-Patchwork-Id: 9731537 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 618A860387 for ; Wed, 17 May 2017 15:51:56 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 53DC126E78 for ; Wed, 17 May 2017 15:51:56 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 48C8A2865C; Wed, 17 May 2017 15:51:56 +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=unavailable 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 8BB1D28655 for ; Wed, 17 May 2017 15:51:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753789AbdEQPvw (ORCPT ); Wed, 17 May 2017 11:51:52 -0400 Received: from lelnx194.ext.ti.com ([198.47.27.80]:52075 "EHLO lelnx194.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753719AbdEQPvu (ORCPT ); Wed, 17 May 2017 11:51:50 -0400 Received: from dflxv15.itg.ti.com ([128.247.5.124]) by lelnx194.ext.ti.com (8.15.1/8.15.1) with ESMTP id v4HFpGC4025270; Wed, 17 May 2017 10:51:16 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ti.com; s=ti-com-17Q1; t=1495036276; bh=hU78KNrMslslXJ/pYToZFrpcgCe69WDaPpsDdPetZgg=; h=From:To:CC:Subject:Date:In-Reply-To:References; b=y1K7PdjESmZOd2SbujxQF2qYTJ3ff35Ri+nKXiweA4Egq53N77e/rWZ6D3xtQUJYB uusG3EZ2c3zHggx0qeO1pRVj5eTEZGTv/jDn884LWwRWayOJe1pSOJxEIW9HkehCIe 1VHSLDEeSvI3ISWzNnObAE17VvaabHFFDfKy7h8Y= Received: from DFLE73.ent.ti.com (dfle73.ent.ti.com [128.247.5.110]) by dflxv15.itg.ti.com (8.14.3/8.13.8) with ESMTP id v4HFpFr5032730; Wed, 17 May 2017 10:51:16 -0500 Received: from dlep32.itg.ti.com (157.170.170.100) by DFLE73.ent.ti.com (128.247.5.110) with Microsoft SMTP Server id 14.3.294.0; Wed, 17 May 2017 10:51:14 -0500 Received: from gomoku.home (ileax41-snat.itg.ti.com [10.172.224.153]) by dlep32.itg.ti.com (8.14.3/8.13.8) with ESMTP id v4HFp8dP008940; Wed, 17 May 2017 10:51:11 -0500 From: Tero Kristo To: , , , CC: , , Paul Walmsley Subject: [PATCHv3 1/4] Documentation: dt-bindings: Add binding documentation for TI clkctrl clocks Date: Wed, 17 May 2017 18:50:06 +0300 Message-ID: <1495036209-11298-2-git-send-email-t-kristo@ti.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1495036209-11298-1-git-send-email-t-kristo@ti.com> References: <1495036209-11298-1-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..48ee699 --- /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 = <2>; + }; + }; + }; +}; + +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>; +};