From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1756058AbbFBLZK (ORCPT <rfc822;w@1wt.eu>);
	Tue, 2 Jun 2015 07:25:10 -0400
Received: from devils.ext.ti.com ([198.47.26.153]:58113 "EHLO
	devils.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S1751949AbbFBLZB (ORCPT
	<rfc822;linux-kernel@vger.kernel.org>);
	Tue, 2 Jun 2015 07:25:01 -0400
Message-ID: <556D925A.9070708@ti.com>
Date: Tue, 2 Jun 2015 16:54:10 +0530
From: Vignesh R <vigneshr@ti.com>
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0
MIME-Version: 1.0
To: Tero Kristo <t-kristo@ti.com>, Paul Walmsley <paul@pwsan.com>,
        Thierry Reding <thierry.reding@gmail.com>,
        Rob Herring <robh+dt@kernel.org>, Pawel Moll <pawel.moll@arm.com>,
        Mark Rutland <mark.rutland@arm.com>,
        Ian Campbell <ijc+devicetree@hellion.org.uk>,
        Kumar Gala <galak@codeaurora.org>,
        Benoit Cousson <bcousson@baylibre.com>,
        Tony Lindgren <tony@atomide.com>,
        Russell King <linux@arm.linux.org.uk>,
        Mike Turquette <mturquette@linaro.org>,
        Stephen Boyd <sboyd@codeaurora.org>
CC: <linux-pwm@vger.kernel.org>, <devicetree@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>, <linux-omap@vger.kernel.org>,
        <linux-arm-kernel@lists.infradead.org>, <linux-clk@vger.kernel.org>
Subject: Re: [PATCH 2/5] ARM: OMAP2+: DRA7: Add hwmod entries for PWMSS
References: <1433159614-437-1-git-send-email-vigneshr@ti.com> <1433159614-437-3-git-send-email-vigneshr@ti.com> <556D6781.2090405@ti.com>
In-Reply-To: <556D6781.2090405@ti.com>
Content-Type: text/plain; charset="windows-1252"
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

Hi Tero,

On Tuesday 02 June 2015 01:51 PM, Tero Kristo wrote:
> On 06/01/2015 02:53 PM, Vignesh R wrote:
>> Add hwmod entries for the PWMSS on DRA7.
> 
> Can you provide some documentation references for this data?
> 
> I was looking at the TRM and at least the main_clk selection is somewhat
> unclear to me.

As per AM57x TRM SPRUHZ6, October 2014, Section 29.1.3 Table 29-4.
source signal as L4PER2_L3_GICLK but it is actually equal to
L4PER2_L3_GICLK/2. l4_root_clock_div is fixed-factored clock equal to
L4PER2_L3_GICLK/2 (l3_iclk_div/2 in Linux clock dt). The TRM does'nt
show factor of by 2. I will forward you an internal documentation that
talks about this.

I also measured the frequencies of PWM waveforms using oscilloscope and
it matches above observation.

I will update the patch description in v2.

Regards
Vignesh