Re: [RFC PATCH 3/8] cpufreq: qcom-nvmem: provide vmin constraint for early Kraits

Konrad Dybcio
2023-07-03T11:39:01Z

On 2.07.2023 19:50, Dmitry Baryshkov wrote:
> Early Krait CPUs required that core voltage was not below 1.15 V.
> Implement this requirement by adding separate config_regulators
> callback.
>
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> ---
"early krait" as in msm8960, or "early krait" as in "pre-production"?

Konrad
> drivers/cpufreq/qcom-cpufreq-nvmem.c | 67 +++++++++++++++++++++++++++-
> 1 file changed, 66 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/cpufreq/qcom-cpufreq-nvmem.c b/drivers/cpufreq/qcom-cpufreq-nvmem.c
> index 113f35668048..9312c8ab62a8 100644
> --- a/drivers/cpufreq/qcom-cpufreq-nvmem.c
> +++ b/drivers/cpufreq/qcom-cpufreq-nvmem.c
> @@ -30,6 +30,8 @@
> #include <linux/slab.h>
> #include <linux/soc/qcom/smem.h>
>
> +#include <asm/cputype.h>
> +
> #include <dt-bindings/arm/qcom,ids.h>
>
> struct qcom_cpufreq_drv;
> @@ -257,6 +259,66 @@ static const struct qcom_cpufreq_match_data match_data_apq8064 = {
> .regulator_names = apq8064_regulator_names,
> };
>
> +static const int krait_needs_vmin(void)
> +{
> + switch (read_cpuid_id()) {
> + case 0x511F04D0: /* KR28M2A20 */
> + case 0x511F04D1: /* KR28M2A21 */
> + case 0x510F06F0: /* KR28M4A10 */
> + return 1;
> + default:
> + return 0;
> + };
> +}
> +
> +#define KRAIT_VMIN 1150000
> +#define KRAIT_VMIN_MAX (KRAIT_VMIN + 25000)
> +static int krait_config_regulator_vmin(struct device *dev,
> + struct dev_pm_opp *old_opp, struct dev_pm_opp *new_opp,
> + struct regulator **regulators, unsigned int count)
> +{
> + struct regulator *reg = regulators[0];
> + struct dev_pm_opp_supply supply;
> + int ret;
> +
> + /* This function only supports single regulator per device */
> + if (WARN_ON(count > 1)) {
> + dev_err(dev, "multiple regulators are not supported\n");
> + return -EINVAL;
> + }
> +
> + if (IS_ERR(reg)) {
> + dev_dbg(dev, "%s: regulator not available: %ld\n", __func__,
> + PTR_ERR(reg));
> + return 0;
> + }
> +
> + ret = dev_pm_opp_get_supplies(new_opp, &supply);
> + if (WARN_ON(ret))
> + return ret;
> +
> + if (supply.u_volt_min < KRAIT_VMIN) {
> + supply.u_volt_min = KRAIT_VMIN;
> + supply.u_volt = KRAIT_VMIN;
> + supply.u_volt_max = KRAIT_VMIN_MAX;
> + }
> +
> + dev_dbg(dev, "%s: voltages (mV): %lu %lu %lu\n", __func__,
> + supply.u_volt_min, supply.u_volt, supply.u_volt_max);
> +
> + ret = regulator_set_voltage_triplet(reg,
> + supply.u_volt_min,
> + supply.u_volt,
> + supply.u_volt_max);
> + if (ret)
> + dev_err(dev, "%s: failed to set voltage (%lu %lu %lu mV): %d\n",
> + __func__, supply.u_volt_min, supply.u_volt,
> + supply.u_volt_max, ret);
> +
> + return ret;
> +}
> +
> +
> static int qcom_cpufreq_probe(struct platform_device *pdev)
> {
> struct qcom_cpufreq_drv *drv;
> @@ -344,8 +406,11 @@ static int qcom_cpufreq_probe(struct platform_device *pdev)
> config.virt_devs = NULL;
> }
>
> - if (drv->data->regulator_names)
> + if (drv->data->regulator_names) {
> config.regulator_names = drv->data->regulator_names;
> + if (krait_needs_vmin())
> + config.config_regulators = krait_config_regulator_vmin;
> + }
>
> if (config.supported_hw ||
> config.genpd_names ||