Re: [PATCH v5 3/3] PM / AVS: SVS: Introduce SVS engine

From: Pi-Hsun Shih
Date: Thu Nov 14 2019 - 02:41:58 EST


Hi Roger,

On Fri, Sep 6, 2019 at 6:06 PM Roger Lu <roger.lu@xxxxxxxxxxxx> wrote:
>
> The SVS (Smart Voltage Scaling) engine is a piece of hardware which is
> used to calculate optimized voltage values of several power domains, e.g.
> CPU/GPU/CCI, according to chip process corner, temperatures, and other
> factors. Then DVFS driver could apply those optimized voltage values to
> reduce power consumption.
>
> Signed-off-by: Roger Lu <roger.lu@xxxxxxxxxxxx>
> ---
> drivers/power/avs/Kconfig | 10 +
> drivers/power/avs/Makefile | 1 +
> drivers/power/avs/mtk_svs.c | 2075 +++++++++++++++++++++++++++++++++
> include/linux/power/mtk_svs.h | 23 +
> 4 files changed, 2109 insertions(+)
> create mode 100644 drivers/power/avs/mtk_svs.c
> create mode 100644 include/linux/power/mtk_svs.h
>
> [...]
> diff --git a/drivers/power/avs/mtk_svs.c b/drivers/power/avs/mtk_svs.c
> new file mode 100644
> index 000000000000..78ec93c3a4a5
> --- /dev/null
> +++ b/drivers/power/avs/mtk_svs.c
> [...]
> +static int svs_set_volts(struct svs_bank *svsb, bool force_update)
> +{
> + u32 i, svsb_volt, opp_volt, low_temp_offset = 0;
> + int zone_temp, ret;
> +
> + mutex_lock(&svsb->lock);
> +
> + /* If bank is suspended, it means init02 voltage is applied.
> + * Don't need to update opp voltage anymore.
> + */
> + if (svsb->suspended && !force_update) {
> + pr_notice("%s: bank is suspended\n", svsb->name);
> + mutex_unlock(&svsb->lock);
> + return -EPERM;
> + }
> +
> + /* get thermal effect */
> + if (svsb->phase == SVS_PHASE_MON) {
> + if (svsb->svs_temp > svsb->upper_temp_bound &&
> + svsb->svs_temp < svsb->lower_temp_bound) {
> + pr_err("%s: svs_temp is abnormal (0x%x)?\n",
> + svsb->name, svsb->svs_temp);
> + mutex_unlock(&svsb->lock);
> + return -EINVAL;
> + }
> +
> + ret = svs_get_zone_temperature(svsb, &zone_temp);
> + if (ret) {
> + pr_err("%s: cannot get zone \"%s\" temperature\n",
> + svsb->name, svsb->zone_name);
> + pr_err("%s: add low_temp_offset = %u\n",
> + svsb->name, svsb->low_temp_offset);
> + zone_temp = svsb->low_temp_threashold;
> + }
> +
> + if (zone_temp <= svsb->low_temp_threashold)
> + low_temp_offset = svsb->low_temp_offset;
> + }
> +
> + /* vmin <= svsb_volt (opp_volt) <= signed-off voltage */
> + for (i = 0; i < svsb->opp_count; i++) {
> + if (svsb->phase == SVS_PHASE_MON) {
> + svsb_volt = max((svsb->volts[i] + svsb->volt_offset +
> + low_temp_offset), svsb->vmin);
> + opp_volt = svs_volt_to_opp_volt(svsb_volt,
> + svsb->volt_step,
> + svsb->volt_base);
> + } else if (svsb->phase == SVS_PHASE_INIT02) {
> + svsb_volt = max((svsb->init02_volts[i] +
> + svsb->volt_offset), svsb->vmin);
> + opp_volt = svs_volt_to_opp_volt(svsb_volt,
> + svsb->volt_step,
> + svsb->volt_base);
> + } else if (svsb->phase == SVS_PHASE_ERROR) {
> + opp_volt = svsb->opp_volts[i];
> + } else {
> + pr_err("%s: unknown phase: %u?\n",
> + svsb->name, svsb->phase);
> + mutex_unlock(&svsb->lock);
> + return -EINVAL;
> + }
> +
> + opp_volt = min(opp_volt, svsb->opp_volts[i]);
> + ret = dev_pm_opp_adjust_voltage(svsb->dev, svsb->opp_freqs[i],
> + opp_volt);

The version of this function in opp tree
(https://git.kernel.org/pub/scm/linux/kernel/git/vireshk/pm.git/commit/?h=opp/linux-next&id=25cb20a212a1f989385dfe23230817e69c62bee5)
has a different function signature, so this should be changed too.

> + if (ret) {
> + pr_err("%s: set voltage failed: %d\n", svsb->name, ret);
> + mutex_unlock(&svsb->lock);
> + return ret;
> + }
> + }
> +
> + mutex_unlock(&svsb->lock);
> +
> + return 0;
> +}
> +
> [...]
> +static int svs_init01(struct mtk_svs *svs)
> +{
> + const struct svs_platform *svsp = svs->platform;
> + struct svs_bank *svsb;
> + struct pm_qos_request qos_request = { {0} };
> + unsigned long flags, time_left;
> + bool search_done;
> + int ret = -EINVAL;
> + u32 opp_freqs, opp_vboot, buck_volt, idx, i;
> +
> + /* Let CPUs leave idle-off state for initializing svs_init01. */
> + pm_qos_add_request(&qos_request, PM_QOS_CPU_DMA_LATENCY, 0);
> +
> + /* Sometimes two svs_bank use the same buck.
> + * Therefore, we set each svs_bank to vboot voltage first.
> + */
> + for (idx = 0; idx < svsp->bank_num; idx++) {
> + svsb = &svsp->banks[idx];
> + search_done = false;
> +
> + if (!svsb->init01_support)
> + continue;
> +
> + ret = regulator_set_mode(svsb->buck, REGULATOR_MODE_FAST);
> + if (ret)
> + pr_notice("%s: fail to set fast mode: %d\n",
> + svsb->name, ret);
> +
> + if (svsb->mtcmos_request) {
> + ret = regulator_enable(svsb->buck);
> + if (ret) {
> + pr_err("%s: fail to enable %s power: %d\n",
> + svsb->name, svsb->buck_name, ret);
> + goto init01_finish;
> + }
> +
> + ret = dev_pm_domain_attach(svsb->dev, false);
> + if (ret) {
> + pr_err("%s: attach pm domain fail: %d\n",
> + svsb->name, ret);
> + goto init01_finish;
> + }
> +
> + pm_runtime_enable(svsb->dev);
> + ret = pm_runtime_get_sync(svsb->dev);
> + if (ret < 0) {
> + pr_err("%s: turn mtcmos on fail: %d\n",
> + svsb->name, ret);
> + goto init01_finish;
> + }
> + }
> +
> + /* Find the fastest freq that can be run at vboot and
> + * fix to that freq until svs_init01 is done.
> + */
> + opp_vboot = svs_volt_to_opp_volt(svsb->vboot,
> + svsb->volt_step,
> + svsb->volt_base);
> +
> + for (i = 0; i < svsb->opp_count; i++) {
> + opp_freqs = svsb->opp_freqs[i];
> + if (!search_done && svsb->opp_volts[i] <= opp_vboot) {
> + ret = dev_pm_opp_adjust_voltage(svsb->dev,
> + opp_freqs,
> + opp_vboot);

Same here.

> + if (ret) {
> + pr_err("%s: set voltage failed: %d\n",
> + svsb->name, ret);
> + goto init01_finish;
> + }
> +
> + search_done = true;
> + } else {
> + dev_pm_opp_disable(svsb->dev,
> + svsb->opp_freqs[i]);
> + }
> + }
> + }
> +
> + for (idx = 0; idx < svsp->bank_num; idx++) {
> + svsb = &svsp->banks[idx];
> + svs->bank = svsb;
> +
> + if (!svsb->init01_support)
> + continue;
> +
> + opp_vboot = svs_volt_to_opp_volt(svsb->vboot,
> + svsb->volt_step,
> + svsb->volt_base);
> +
> + buck_volt = regulator_get_voltage(svsb->buck);
> + if (buck_volt != opp_vboot) {
> + pr_err("%s: buck voltage: %u, expected vboot: %u\n",
> + svsb->name, buck_volt, opp_vboot);
> + ret = -EPERM;
> + goto init01_finish;
> + }
> +
> + init_completion(&svsb->init_completion);
> + flags = claim_mtk_svs_lock();
> + svs_set_phase(svs, SVS_PHASE_INIT01);
> + release_mtk_svs_lock(flags);
> + time_left =
> + wait_for_completion_timeout(&svsb->init_completion,
> + msecs_to_jiffies(2000));
> + if (time_left == 0) {
> + pr_err("%s: init01 completion timeout\n", svsb->name);
> + ret = -EBUSY;
> + goto init01_finish;
> + }
> + }
> +
> +init01_finish:
> + for (idx = 0; idx < svsp->bank_num; idx++) {
> + svsb = &svsp->banks[idx];
> +
> + if (!svsb->init01_support)
> + continue;
> +
> + for (i = 0; i < svsb->opp_count; i++)
> + dev_pm_opp_enable(svsb->dev, svsb->opp_freqs[i]);
> +
> + if (regulator_set_mode(svsb->buck, REGULATOR_MODE_NORMAL))
> + pr_notice("%s: fail to set normal mode: %d\n",
> + svsb->name, ret);
> +
> + if (svsb->mtcmos_request) {
> + if (pm_runtime_put_sync(svsb->dev))
> + pr_err("%s: turn mtcmos off fail: %d\n",
> + svsb->name, ret);
> + pm_runtime_disable(svsb->dev);
> + dev_pm_domain_detach(svsb->dev, 0);
> + if (regulator_disable(svsb->buck))
> + pr_err("%s: fail to disable %s power: %d\n",
> + svsb->name, svsb->buck_name, ret);
> + }
> + }
> +
> + pm_qos_remove_request(&qos_request);
> +
> + return ret;
> +}
> +
> [...]