Re: [PATCH 2/2] cpufreq: qcom-cpufreq-hw: Fix throttle frequency value on EPSS platforms

[Bjorn Andersson <bjorn.andersson@linaro.org>]

On Mon 28 Mar 04:28 PDT 2022, Vladimir Zapolskiy wrote:

> On QCOM platforms with EPSS flavour of cpufreq IP a throttled frequency is
> obtained from another register REG_DOMAIN_STATE, thus the helper function
> qcom_lmh_get_throttle_freq() should be modified accordingly, as for now
> it returns gibberish since .reg_current_vote is unset for EPSS hardware.
> 

Perhaps add a paragraph here to mention that you're replacing
19200 * HZ_PER_KHZ with xo_rate in this patch as well?

> Fixes: 275157b367f4 ("cpufreq: qcom-cpufreq-hw: Add dcvs interrupt support")
> Signed-off-by: Vladimir Zapolskiy <vladimir.zapolskiy@linaro.org>

Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>

Regards,
Bjorn

> ---
>  drivers/cpufreq/qcom-cpufreq-hw.c | 17 +++++++++++------
>  1 file changed, 11 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/cpufreq/qcom-cpufreq-hw.c b/drivers/cpufreq/qcom-cpufreq-hw.c
> index 53954e5086e0..3156d79ef39e 100644
> --- a/drivers/cpufreq/qcom-cpufreq-hw.c
> +++ b/drivers/cpufreq/qcom-cpufreq-hw.c
> @@ -30,6 +30,7 @@
>  
>  struct qcom_cpufreq_soc_data {
>  	u32 reg_enable;
> +	u32 reg_domain_state;
>  	u32 reg_dcvs_ctrl;
>  	u32 reg_freq_lut;
>  	u32 reg_volt_lut;
> @@ -283,11 +284,16 @@ static void qcom_get_related_cpus(int index, struct cpumask *m)
>  	}
>  }
>  
> -static unsigned int qcom_lmh_get_throttle_freq(struct qcom_cpufreq_data *data)
> +static unsigned long qcom_lmh_get_throttle_freq(struct qcom_cpufreq_data *data)
>  {
> -	unsigned int val = readl_relaxed(data->base + data->soc_data->reg_current_vote);
> +	unsigned int lval;
>  
> -	return (val & 0x3FF) * 19200;
> +	if (data->soc_data->reg_current_vote)
> +		lval = readl_relaxed(data->base + data->soc_data->reg_current_vote) & 0x3ff;
> +	else
> +		lval = readl_relaxed(data->base + data->soc_data->reg_domain_state) & 0xff;
> +
> +	return lval * xo_rate;
>  }
>  
>  static void qcom_lmh_dcvs_notify(struct qcom_cpufreq_data *data)
> @@ -297,14 +303,12 @@ static void qcom_lmh_dcvs_notify(struct qcom_cpufreq_data *data)
>  	struct device *dev = get_cpu_device(cpu);
>  	unsigned long freq_hz, throttled_freq;
>  	struct dev_pm_opp *opp;
> -	unsigned int freq;
>  
>  	/*
>  	 * Get the h/w throttled frequency, normalize it using the
>  	 * registered opp table and use it to calculate thermal pressure.
>  	 */
> -	freq = qcom_lmh_get_throttle_freq(data);
> -	freq_hz = freq * HZ_PER_KHZ;
> +	freq_hz = qcom_lmh_get_throttle_freq(data);
>  
>  	opp = dev_pm_opp_find_freq_floor(dev, &freq_hz);
>  	if (IS_ERR(opp) && PTR_ERR(opp) == -ERANGE)
> @@ -371,6 +375,7 @@ static const struct qcom_cpufreq_soc_data qcom_soc_data = {
>  
>  static const struct qcom_cpufreq_soc_data epss_soc_data = {
>  	.reg_enable = 0x0,
> +	.reg_domain_state = 0x20,
>  	.reg_dcvs_ctrl = 0xb0,
>  	.reg_freq_lut = 0x100,
>  	.reg_volt_lut = 0x200,
> -- 
> 2.33.0
>