Linux-ARM-MSM Archive on lore.kernel.org
 help / color / Atom feed
From: Taniya Das <tdas@codeaurora.org>
To: Stephen Boyd <sboyd@kernel.org>,
	Michael Turquette <mturquette@baylibre.com>
Cc: David Brown <david.brown@linaro.org>,
	Rajendra Nayak <rnayak@codeaurora.org>,
	linux-arm-msm@vger.kernel.org, linux-soc@vger.kernel.org,
	linux-clk@vger.kernel.org, linux-kernel@vger.kernel.org,
	Andy Gross <agross@kernel.org>,
	devicetree@vger.kernel.org, robh@kernel.org, robh+dt@kernel.org
Subject: Re: [PATCH v2 1/3] clk: qcom: clk-alpha-pll: Add support for controlling Agera PLLs
Date: Sat, 17 Oct 2020 00:08:58 +0530
Message-ID: <1d969460-92c7-ce9a-d727-2c0a31c5d3c5@codeaurora.org> (raw)
In-Reply-To: <160264125446.310579.18150875025884105137@swboyd.mtv.corp.google.com>

Thanks Stephen for the review comments.

On 10/14/2020 7:37 AM, Stephen Boyd wrote:
> Quoting Taniya Das (2020-10-13 10:11:48)
>> diff --git a/drivers/clk/qcom/clk-alpha-pll.c b/drivers/clk/qcom/clk-alpha-pll.c
>> index 26139ef..17e1fc0 100644
>> --- a/drivers/clk/qcom/clk-alpha-pll.c
>> +++ b/drivers/clk/qcom/clk-alpha-pll.c
>> @@ -1561,3 +1571,73 @@ const struct clk_ops clk_alpha_pll_postdiv_lucid_ops = {
>>          .set_rate = clk_alpha_pll_postdiv_fabia_set_rate,
>>   };
>>   EXPORT_SYMBOL_GPL(clk_alpha_pll_postdiv_lucid_ops);
>> +
>> +void clk_agera_pll_configure(struct clk_alpha_pll *pll, struct regmap *regmap,
>> +                       const struct alpha_pll_config *config)
>> +{
>> +       if (config->l)
>> +               regmap_write(regmap, PLL_L_VAL(pll), config->l);
> 
> Maybe make a helper function for this too. That way we can't mix up the
> if condition with the value in the write.
> 

Sure, I will add a helper function.

> 	clk_alpha_pll_write_config(regmap, PLL_L_VAL(pll), config->l);
> 
> static void clk_alpha_pll_write_config(struct regmap *regmap,
> 				       unsigned int reg,
> 				       unsigned int val) {
> 	if (val)
> 		regmap_write(regmap, reg, val);
> }
> 
> and how are we so lucky that zero isn't a value that we may need to
> write?
> 
>> +
>> +       if (config->alpha)
>> +               regmap_write(regmap, PLL_ALPHA_VAL(pll), config->alpha);
>> +
>> +       if (config->user_ctl_val)
>> +               regmap_write(regmap, PLL_USER_CTL(pll), config->user_ctl_val);
>> +
>> +       if (config->config_ctl_val)
>> +               regmap_write(regmap, PLL_CONFIG_CTL(pll),
>> +                                               config->config_ctl_val);
>> +
>> +       if (config->config_ctl_hi_val)
>> +               regmap_write(regmap, PLL_CONFIG_CTL_U(pll),
>> +                                               config->config_ctl_hi_val);
>> +
>> +       if (config->test_ctl_val)
>> +               regmap_write(regmap, PLL_TEST_CTL(pll),
>> +                                               config->test_ctl_val);
>> +
>> +       if (config->test_ctl_hi_val)
>> +               regmap_write(regmap,  PLL_TEST_CTL_U(pll),
>> +                                               config->test_ctl_hi_val);
>> +}
>> +EXPORT_SYMBOL_GPL(clk_agera_pll_configure);
>> +
>> +static int clk_alpha_pll_agera_set_rate(struct clk_hw *hw, unsigned long rate,
>> +                                                       unsigned long prate)
>> +{
>> +       struct clk_alpha_pll *pll = to_clk_alpha_pll(hw);
>> +       u32 l, alpha_width = pll_alpha_width(pll);
>> +       unsigned long rrate, max = rate + PLL_RATE_MARGIN;
>> +       u64 a;
>> +
>> +       rrate = alpha_pll_round_rate(rate, prate, &l, &a, alpha_width);
>> +
>> +       /*
>> +        * Due to limited number of bits for fractional rate programming, the
>> +        * rounded up rate could be marginally higher than the requested rate.
>> +        */
>> +       if (rrate > (rate + PLL_RATE_MARGIN) || rrate < rate) {
>> +               pr_err("%s: Rounded rate %lu not within range [%lu, %lu)\n",
>> +                      clk_hw_get_name(hw), rrate, rate, max);
>> +               return -EINVAL;
>> +       }
> 
> Can this be extracted into a helper function?
> 

Yes, I will add this too.

>> +
>> +       /* change L_VAL without having to go through the power on sequence */
>> +       regmap_write(pll->clkr.regmap, PLL_L_VAL(pll), l);
>> +       regmap_write(pll->clkr.regmap, PLL_ALPHA_VAL(pll), a);
>> +
>> +       if (clk_hw_is_enabled(hw))
>> +               return wait_for_pll_enable_lock(pll);
>> +
>> +       return 0;
>> +}
>> +

-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
of Code Aurora Forum, hosted by The Linux Foundation.

--

  reply index

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-10-13 17:11 [PATCH v2 0/3] Add Camera clock controller driver for SC7180 Taniya Das
2020-10-13 17:11 ` [PATCH v2 1/3] clk: qcom: clk-alpha-pll: Add support for controlling Agera PLLs Taniya Das
2020-10-14  2:07   ` Stephen Boyd
2020-10-16 18:38     ` Taniya Das [this message]
2020-10-13 17:11 ` [PATCH v2 2/3] dt-bindings: clock: Add YAML schemas for the QCOM Camera clock bindings Taniya Das
2020-10-14  2:09   ` Stephen Boyd
2020-10-16 18:39     ` Taniya Das
2020-10-16 17:25   ` Rob Herring
2020-10-13 17:11 ` [PATCH v2 3/3] clk: qcom: camcc: Add camera clock controller driver for SC7180 Taniya Das
2020-10-14  1:59   ` Stephen Boyd
2020-10-16 18:40     ` Taniya Das

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1d969460-92c7-ce9a-d727-2c0a31c5d3c5@codeaurora.org \
    --to=tdas@codeaurora.org \
    --cc=agross@kernel.org \
    --cc=david.brown@linaro.org \
    --cc=devicetree@vger.kernel.org \
    --cc=linux-arm-msm@vger.kernel.org \
    --cc=linux-clk@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-soc@vger.kernel.org \
    --cc=mturquette@baylibre.com \
    --cc=rnayak@codeaurora.org \
    --cc=robh+dt@kernel.org \
    --cc=robh@kernel.org \
    --cc=sboyd@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-ARM-MSM Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-arm-msm/0 linux-arm-msm/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-arm-msm linux-arm-msm/ https://lore.kernel.org/linux-arm-msm \
		linux-arm-msm@vger.kernel.org
	public-inbox-index linux-arm-msm

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-arm-msm


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git