From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752385AbcD1IEZ (ORCPT ); Thu, 28 Apr 2016 04:04:25 -0400 Received: from devils.ext.ti.com ([198.47.26.153]:53333 "EHLO devils.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752314AbcD1IES (ORCPT ); Thu, 28 Apr 2016 04:04:18 -0400 Subject: Re: [PATCH v2 4/5] ARM: dts: omap5: describe control for ckobuffer To: "H. Nikolaus Schaller" , Peter Ujfalusi References: <20160426172710.GI5995@atomide.com> <70572DA1-BEB4-4681-BA6C-2E1C9002D730@goldelico.com> <5720B107.4000907@ti.com> <5720C85B.9010701@ti.com> <40536322-073F-48BD-9D07-32B9A9F07AF2@goldelico.com> CC: Tony Lindgren , =?UTF-8?Q?Beno=c3=aet_Cousson?= , Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , Russell King , Laxman Dewangan , linux-omap , , LKML , Marek Belisko , , Discussions about the Letux Kernel From: Tero Kristo Message-ID: <5721C3D4.7040401@ti.com> Date: Thu, 28 Apr 2016 11:03:32 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.6.0 MIME-Version: 1.0 In-Reply-To: <40536322-073F-48BD-9D07-32B9A9F07AF2@goldelico.com> Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 27/04/16 17:35, H. Nikolaus Schaller wrote: > HI, > >> Am 27.04.2016 um 16:23 schrieb Peter Ujfalusi : >> >> On 04/27/2016 05:10 PM, Tero Kristo wrote: >>> On 27/04/16 16:10, H. Nikolaus Schaller wrote: >>>> >>>>> Am 27.04.2016 um 14:31 schrieb Tero Kristo : >>>>> >>>>> On 27/04/16 09:04, H. Nikolaus Schaller wrote: >>>>>> >>>>>>> Am 26.04.2016 um 19:27 schrieb Tony Lindgren : >>>>>>> >>>>>>> Tero, >>>>>>> >>>>>>> * H. Nikolaus Schaller [160418 11:23]: >>>>>>>> OMAP5 has a register to control if the ckobuffer is enabled >>>>>>>> and defines the polarity. ckobuffer is required to drive a twl6040 >>>>>>>> with the system clock. Hence, add the pinctrl,single to the >>>>>>>> OMAP5 SoC description so that omap5-board-common can >>>>>>>> set up the ckobuffer as required. >>>>>>> >>>>>>> Is this really a mux or should it be a mux clock? >>>>>> >>>>>> It is a pinmux setting for the clock out buffer to choose what signal >>>>>> (and polarity) is presented on the fref_xtal_clk pad. >>>>>> >>>>>> The register is part of the CTRL_MODULE_WKUP. >>>>>> The clock signal is the xtal master clock of the whole SoC. >>>>>> >>>>>> Although there is a bit to choose an alternate clock, there is no >>>>>> alternate in the OMAP5 silicon. >>>>>> >>>>>> Therefore I would say it is about padconf and not clock or clock mux >>>>>> related. >>>>>> >>>>>> It just happens to be a clock signal which can be routed to this >>>>>> pad. >>>>> >>>>> The two could very well be implemented as clock nodes, a mux and a gate. >>>>> This would describe the hardware functionality better imo, if the >>>>> assumptions made here are correct. Implementing the control as pinctrl >>>>> hacks looks rather weird to me. >>>> >>>> Why do you consider it a "pinctrl hack"? IMHO it is not a hack, but 100% >>>> proper use of pinctrl. >>> >>> It is just the level of abstraction we are talking about here. If it is a >>> clock we are controlling, we should rather control it as a clock (higher level >>> abstraction), not a pin. >> >> I second this. I think it is better to have a simple gate clock and handle >> only CONTROL_CKOBUFFER:CKOBUFFER_CLK_EN (bit 28) only as the other bits does >> not have real use. >> >> Then we can add clk API support for this. On most OMAP4 devices the clock is >> always on, > > this is why I am raising the question if we really want to control it on the omap5 or just > turn it on for all omap5 boards like the omap4 appears to do... I.e. if turning the pin on > as a pinctrl is IMHO sufficient for all practical purposes. > >> so the board DTS file need to provide a dummy clock, or we can make >> the high precision clock also as optional (on panda both OMAP4 and twl6040 >> uses the same reference clock). > > Hm. It looks as if implementing this (and clock gating) is beyond my experiences. > But I am happy to test a proposal on our omap5 board. > > BR and thanks, > Nikolaus See the inline patch, this implements the fref_xtal_ck. I had to add some kernel code also to cope with the new SCM area, but the same area can now be accessed via syscon also if needed. From: Tero Kristo Date: Thu, 28 Apr 2016 11:00:57 +0300 Subject: [PATCH] ARM: omap5: add support for fref_xtal_ck Signed-off-by: Tero Kristo --- arch/arm/boot/dts/omap5.dtsi | 22 ++++++++++++++++++++++ arch/arm/boot/dts/omap54xx-clocks.dtsi | 10 ++++++++++ arch/arm/mach-omap2/control.c | 20 ++++++++++++++++---- include/linux/clk/ti.h | 1 + 4 files changed, 49 insertions(+), 4 deletions(-) diff --git a/arch/arm/boot/dts/omap5.dtsi b/arch/arm/boot/dts/omap5.dtsi index 38805eb..bdc6528 100644 --- a/arch/arm/boot/dts/omap5.dtsi +++ b/arch/arm/boot/dts/omap5.dtsi @@ -277,6 +277,28 @@ pinctrl-single,register-width = <16>; pinctrl-single,function-mask = <0x7fff>; }; + + omap5_scm_wkup_pad_conf: omap5_scm_wkup_pad_conf@cda0 { + compatible = "ti,omap5-scm-wkup-pad-conf", + "simple-bus"; + reg = <0xcda0 0x60>; + #address-cells = <1>; + #size-cells = <1>; + ranges = <0 0xcda0 0x60>; + + scm_wkup_pad_conf: scm_conf@0 { + compatible = "syscon", "simple-bus"; + reg = <0x0 0x60>; + #address-cells = <1>; + #size-cells = <1>; + ranges = <0 0x0 0x60>; + + scm_wkup_pad_conf_clocks: clocks@0 { + #address-cells = <1>; + #size-cells = <0>; + }; + }; + }; }; ocmcram: ocmcram@40300000 { diff --git a/arch/arm/boot/dts/omap54xx-clocks.dtsi b/arch/arm/boot/dts/omap54xx-clocks.dtsi index 83b425f..f970dac 100644 --- a/arch/arm/boot/dts/omap54xx-clocks.dtsi +++ b/arch/arm/boot/dts/omap54xx-clocks.dtsi @@ -1388,3 +1388,13 @@ reg = <0x021c>; }; }; + +&scm_wkup_pad_conf_clocks { + fref_xtal_ck: fref_xtal_ck { + #clocks-cells = <0>; + compatible = "ti,gate-clock"; + clocks = <&sys_clkin>; + ti,bit-shift = <28>; + reg = <0x14>; + }; +}; diff --git a/arch/arm/mach-omap2/control.c b/arch/arm/mach-omap2/control.c index 1662071..5956641 100644 --- a/arch/arm/mach-omap2/control.c +++ b/arch/arm/mach-omap2/control.c @@ -623,6 +623,7 @@ void __init omap3_ctrl_init(void) struct control_init_data { int index; + void __iomem *mem; s16 offset; }; @@ -635,6 +636,10 @@ static const struct control_init_data omap2_ctrl_data = { .offset = -OMAP2_CONTROL_GENERAL, }; +static const struct control_init_data ctrl_aux_data = { + .index = TI_CLKM_CTRL_AUX, +}; + static const struct of_device_id omap_scrm_dt_match_table[] = { { .compatible = "ti,am3-scm", .data = &ctrl_data }, { .compatible = "ti,am4-scm", .data = &ctrl_data }, @@ -644,6 +649,7 @@ static const struct of_device_id omap_scrm_dt_match_table[] = { { .compatible = "ti,dm816-scrm", .data = &ctrl_data }, { .compatible = "ti,omap4-scm-core", .data = &ctrl_data }, { .compatible = "ti,omap5-scm-core", .data = &ctrl_data }, + { .compatible = "ti,omap5-scm-wkup-pad-conf", .data = &ctrl_aux_data }, { .compatible = "ti,dra7-scm-core", .data = &ctrl_data }, { } }; @@ -660,15 +666,21 @@ int __init omap2_control_base_init(void) struct device_node *np; const struct of_device_id *match; struct control_init_data *data; + void __iomem *mem; for_each_matching_node_and_match(np, omap_scrm_dt_match_table, &match) { data = (struct control_init_data *)match->data; - omap2_ctrl_base = of_iomap(np, 0); - if (!omap2_ctrl_base) + mem = of_iomap(np, 0); + if (!mem) return -ENOMEM; - omap2_ctrl_offset = data->offset; + if (data->index == TI_CLKM_CTRL) { + omap2_ctrl_base = mem; + omap2_ctrl_offset = data->offset; + } + + data->mem = mem; } return 0; @@ -713,7 +725,7 @@ int __init omap_control_init(void) } else { /* No scm_conf found, direct access */ ret = omap2_clk_provider_init(np, data->index, NULL, - omap2_ctrl_base); + data->mem); if (ret) return ret; } diff --git a/include/linux/clk/ti.h b/include/linux/clk/ti.h index dc5164a..be25aa8 100644 --- a/include/linux/clk/ti.h +++ b/include/linux/clk/ti.h @@ -195,6 +195,7 @@ enum { TI_CLKM_PRM, TI_CLKM_SCRM, TI_CLKM_CTRL, + TI_CLKM_CTRL_AUX, TI_CLKM_PLLSS, CLK_MAX_MEMMAPS };