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SubjectRe: [PATCH v2 1/3] clk: qcom: clk-alpha-pll: Add support for controlling Agera PLLs
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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.

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