linux-kernel - Re: [PATCH 03/27] rtc: ac100: convert from divider_round_rate() to divider_determine

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Message-ID: <aXFz05Tnm8MmQbBD@redhat.com>
Date: Wed, 21 Jan 2026 19:48:19 -0500
From: Brian Masney <bmasney@...hat.com>
To: Alexandre Belloni <alexandre.belloni@...tlin.com>
Cc: Michael Turquette <mturquette@...libre.com>,
	Stephen Boyd <sboyd@...nel.org>, linux-clk@...r.kernel.org,
	linux-kernel@...r.kernel.org, linux-rtc@...r.kernel.org
Subject: Re: [PATCH 03/27] rtc: ac100: convert from divider_round_rate() to
 divider_determine_rate()

Hi Alexandre,

On Thu, Jan 22, 2026 at 01:26:09AM +0100, Alexandre Belloni wrote:
> On 08/01/2026 16:16:21-0500, Brian Masney wrote:
> > The divider_round_rate() function is now deprecated, so let's migrate
> > to divider_determine_rate() instead so that this deprecated API can be
> > removed.
> > 
> > Signed-off-by: Brian Masney <bmasney@...hat.com>
> > 
> > ---
> > To: Alexandre Belloni <alexandre.belloni@...tlin.com>
> > Cc: linux-rtc@...r.kernel.org
> > ---
> >  drivers/rtc/rtc-ac100.c | 75 +++++++++++++++++++++++++------------------------
> >  1 file changed, 38 insertions(+), 37 deletions(-)
> > 
> > diff --git a/drivers/rtc/rtc-ac100.c b/drivers/rtc/rtc-ac100.c
> > index 33626311fa781b5ce90dcc472f948dc933bbc897..16aca4431da8c029e6195d8a3c9fe75fa95d0bc0 100644
> > --- a/drivers/rtc/rtc-ac100.c
> > +++ b/drivers/rtc/rtc-ac100.c
> > @@ -140,42 +140,16 @@ static unsigned long ac100_clkout_recalc_rate(struct clk_hw *hw,
> >  				   AC100_CLKOUT_DIV_WIDTH);
> >  }
> >  
> > -static long ac100_clkout_round_rate(struct clk_hw *hw, unsigned long rate,
> > -				    unsigned long prate)
> > -{
> > -	unsigned long best_rate = 0, tmp_rate, tmp_prate;
> > -	int i;
> > -
> > -	if (prate == AC100_RTC_32K_RATE)
> > -		return divider_round_rate(hw, rate, &prate, NULL,
> > -					  AC100_CLKOUT_DIV_WIDTH,
> > -					  CLK_DIVIDER_POWER_OF_TWO);
> > -
> > -	for (i = 0; ac100_clkout_prediv[i].div; i++) {
> > -		tmp_prate = DIV_ROUND_UP(prate, ac100_clkout_prediv[i].val);
> > -		tmp_rate = divider_round_rate(hw, rate, &tmp_prate, NULL,
> > -					      AC100_CLKOUT_DIV_WIDTH,
> > -					      CLK_DIVIDER_POWER_OF_TWO);
> > -
> > -		if (tmp_rate > rate)
> > -			continue;
> > -		if (rate - tmp_rate < best_rate - tmp_rate)
> > -			best_rate = tmp_rate;
> > -	}
> > -
> > -	return best_rate;
> > -}
> > -
> >  static int ac100_clkout_determine_rate(struct clk_hw *hw,
> >  				       struct clk_rate_request *req)
> >  {
> > -	struct clk_hw *best_parent;
> > +	int i, ret, num_parents = clk_hw_get_num_parents(hw);
> > +	struct clk_hw *best_parent = NULL;
> >  	unsigned long best = 0;
> > -	int i, num_parents = clk_hw_get_num_parents(hw);
> >  
> >  	for (i = 0; i < num_parents; i++) {
> >  		struct clk_hw *parent = clk_hw_get_parent_by_index(hw, i);
> > -		unsigned long tmp, prate;
> > +		unsigned long prate;
> >  
> >  		/*
> >  		 * The clock has two parents, one is a fixed clock which is
> > @@ -199,13 +173,40 @@ static int ac100_clkout_determine_rate(struct clk_hw *hw,
> >  
> >  		prate = clk_hw_get_rate(parent);
> >  
> > -		tmp = ac100_clkout_round_rate(hw, req->rate, prate);
> > -
> > -		if (tmp > req->rate)
> > -			continue;
> > -		if (req->rate - tmp < req->rate - best) {
> > -			best = tmp;
> > -			best_parent = parent;
> > +		if (prate == AC100_RTC_32K_RATE) {
> > +			struct clk_rate_request div_req = *req;
> > +
> > +			div_req.best_parent_rate = prate;
> > +
> > +			ret = divider_determine_rate(hw, &div_req, NULL,
> > +						     AC100_CLKOUT_DIV_WIDTH,
> > +						     CLK_DIVIDER_POWER_OF_TWO);
> > +			if (ret != 0 || div_req.rate > req->rate)
> > +				continue;
> 
> This leaves a braces inbalance

To be clear, you also want the braces around the if like this:

if (ret != 0 || div_req.rate > req->rate) {
	continue;
} else if (req->rate - div_req.rate < req->rate - best) {
	best = div_req.rate;
	best_parent = parent;
}

Brian