From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751953AbdAYKho (ORCPT ); Wed, 25 Jan 2017 05:37:44 -0500 Received: from lelnx194.ext.ti.com ([198.47.27.80]:9255 "EHLO lelnx194.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751672AbdAYKhm (ORCPT ); Wed, 25 Jan 2017 05:37:42 -0500 Subject: Re: [PATCH] clk: ti: divider: Add the table parsing to get the best divider value To: References: <1480669543-16197-1-git-send-email-j-keerthy@ti.com> CC: , , , , From: Keerthy Message-ID: <98780c76-0ba8-85ec-ca01-392f36fa91ad@ti.com> Date: Wed, 25 Jan 2017 16:07:35 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.2.0 MIME-Version: 1.0 In-Reply-To: <1480669543-16197-1-git-send-email-j-keerthy@ti.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 Friday 02 December 2016 02:35 PM, Keerthy wrote: > Currently the divider selection logic blindly divides the parent_rate > by the clk rate and gives the divider value for the divider clocks > which do not have the CLK_SET_RATE_PARENT flag set. Add the clk divider > table parsing to get the closest divider available in the table > provided via Device tree. > > The code is pretty much taken from: drivers/clk/clk-divider.c. > and used here to fix up the best divider selection logic. A gentle ping on this patch. This applies cleanly on the next branch as on today. Let me know if this needs to be rebased. - Keerthy > > Signed-off-by: Keerthy > Reported-by: Richard Woodruff > --- > drivers/clk/ti/divider.c | 31 ++++++++++++++++++++++++++++++- > 1 file changed, 30 insertions(+), 1 deletion(-) > > diff --git a/drivers/clk/ti/divider.c b/drivers/clk/ti/divider.c > index b4e5de1..6bb8778 100644 > --- a/drivers/clk/ti/divider.c > +++ b/drivers/clk/ti/divider.c > @@ -140,6 +140,35 @@ static bool _is_valid_div(struct clk_divider *divider, unsigned int div) > return true; > } > > +static int _div_round_up(const struct clk_div_table *table, > + unsigned long parent_rate, unsigned long rate) > +{ > + const struct clk_div_table *clkt; > + int up = INT_MAX; > + int div = DIV_ROUND_UP_ULL((u64)parent_rate, rate); > + > + for (clkt = table; clkt->div; clkt++) { > + if (clkt->div == div) > + return clkt->div; > + else if (clkt->div < div) > + continue; > + > + if ((clkt->div - div) < (up - div)) > + up = clkt->div; > + } > + > + return up; > +} > + > +static int _div_round(const struct clk_div_table *table, > + unsigned long parent_rate, unsigned long rate) > +{ > + if (!table) > + return DIV_ROUND_UP(parent_rate, rate); > + > + return _div_round_up(table, parent_rate, rate); > +} > + > static int ti_clk_divider_bestdiv(struct clk_hw *hw, unsigned long rate, > unsigned long *best_parent_rate) > { > @@ -155,7 +184,7 @@ static int ti_clk_divider_bestdiv(struct clk_hw *hw, unsigned long rate, > > if (!(clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT)) { > parent_rate = *best_parent_rate; > - bestdiv = DIV_ROUND_UP(parent_rate, rate); > + bestdiv = _div_round(divider->table, parent_rate, rate); > bestdiv = bestdiv == 0 ? 1 : bestdiv; > bestdiv = bestdiv > maxdiv ? maxdiv : bestdiv; > return bestdiv; >