linux-kernel - Re: [PATCH V0 2/2] iio: adc: sprd_pmic_adc: Add support for UMP serise pmic adc

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Message-ID: <20230910145706.7cae84aa@jic23-huawei>
Date:   Sun, 10 Sep 2023 14:57:06 +0100
From:   Jonathan Cameron <jic23@...nel.org>
To:     杨明金 <magicyangmingjin@...il.com>
Cc:     Mingjin Yang <mingjin.yang@...soc.com>,
        Lars-Peter Clausen <lars@...afoo.de>,
        Rob Herring <robh+dt@...nel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>,
        Conor Dooley <conor+dt@...nel.org>, Ling_Ling.Xu@...soc.com,
        Jinfeng.Lin1@...soc.com, Yangbin.Li@...soc.com,
        Jiansheng.Wu@...soc.com, Orson Zhai <orsonzhai@...il.com>,
        Baolin Wang <baolin.wang@...ux.alibaba.com>,
        Chunyan Zhang <zhang.lyra@...il.com>,
        linux-iio@...r.kernel.org, devicetree@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH V0 2/2] iio: adc: sprd_pmic_adc: Add support for UMP
 serise pmic adc

On Tue, 5 Sep 2023 10:59:33 +0800
杨明金 <magicyangmingjin@...il.com> wrote:

> > > > > +static int sprd_adc_enable(struct sprd_adc_data *data, int channel)
> > > > > +{
> > > > > +     int ret = 0;
> > > > > +     u32 reg_read = 0;
> > > > > +
> > > > > +     if (data->pm_data.clk_regmap) {
> > > > > +             ret = regmap_update_bits(data->pm_data.clk_regmap, data->pm_data.clk_reg,
> > > > > +                                      data->pm_data.clk_reg_mask,
> > > > > +                                      data->pm_data.clk_reg_mask);
> > > > > +             ret |= regmap_read(data->pm_data.clk_regmap, data->pm_data.clk_reg, &reg_read);
> > > > > +             if (ret) {
> > > > > +                     dev_err(data->dev, "failed to enable clk26m, channel %d\n", channel);
> > > > > +                     return ret;
> > > > > +             }
> > > > > +             dev_dbg(data->dev, "enable clk26m: ch %d, reg_read 0x%x\n", channel, reg_read);  
> > > >
> > > > Directly accessing the regmap of a clock seems unusual. Why not provide generic clock interfaces
> > > > for this?  
> > >
> > > This register is used to vote to enable/disable the pmic 26m clk which
> > > is provided to modules like audio, typec and adc.
> > > Therefore, this clk cannot be disabled or enabled directly.  
> >
> > clk_enable() and friends support reference counted enable and disable
> > so I don't understand why this needs something unusual.  
> 
> Through communication with internal clk colleagues,
> I learned that this register is not a traditional eb register,

eb?

Sorry, I'm not familiar with the term.

> so the current clk driver is not configured to support this.
> 
> Jonathan Cameron <jic23@...nel.org> 于2023年9月3日周日 19:14写道：
> >
> > On Wed, 30 Aug 2023 15:15:12 +0800
> > 杨明金 <magicyangmingjin@...il.com> wrote:
> >