[PATCH 8/8] devfreq: mediatek: cci devfreq register opp notification for SVS support

Andrew-sh.Cheng
2019-05-16T09:08:45Z

From: "Andrew-sh.Cheng" <andrew-sh.cheng@mediatek.com>

SVS will change the voltage of opp item.
CCI devfreq need to react to change frequency.

Signed-off-by: Andrew-sh.Cheng <andrew-sh.cheng@mediatek.com>
---
drivers/devfreq/mt8183-cci-devfreq.c | 63 ++++++++++++++++++++++++++++++++++++
1 file changed, 63 insertions(+)

diff --git a/drivers/devfreq/mt8183-cci-devfreq.c b/drivers/devfreq/mt8183-cci-devfreq.c
index 818a167c442f..250c963789f3 100644
--- a/drivers/devfreq/mt8183-cci-devfreq.c
+++ b/drivers/devfreq/mt8183-cci-devfreq.c
@@ -19,7 +19,10 @@ struct cci_devfreq {
struct regulator *proc_reg;
unsigned long proc_reg_uV;
struct clk *cci_clk;
+ unsigned long freq;
struct notifier_block nb;
+ struct notifier_block opp_nb;
+ int cci_min_freq;
};

static int cci_devfreq_regulator_notifier(struct notifier_block *nb,
@@ -65,17 +68,62 @@ static int cci_devfreq_regulator_notifier(struct notifier_block *nb,
return 0;
}

+static int ccidevfreq_opp_notifier(struct notifier_block *nb,
+unsigned long event, void *data)
+{
+ int ret;
+ struct dev_pm_opp *opp = data;
+ struct cci_devfreq *cci_df = container_of(nb, struct cci_devfreq,
+ opp_nb);
+ unsigned long freq, volt, cur_volt;
+
+ if (event == OPP_EVENT_ADJUST_VOLTAGE) {
+ freq = dev_pm_opp_get_freq(opp);
+ /* current opp item is changed */
+ if (freq == cci_df->freq) {
+ volt = dev_pm_opp_get_voltage(opp);
+ cur_volt = regulator_get_voltage(cci_df->proc_reg);
+
+ if (volt > cur_volt) {
+ /* need reduce freq */
+ mutex_lock(&cci_df->devfreq->lock);
+ ret = update_devfreq(cci_df->devfreq);
+ if (ret)
+ pr_err("Fail to reduce cci frequency by opp notification: %d\n",
+ ret);
+ mutex_unlock(&cci_df->devfreq->lock);
+ }
+ }
+
+ if (freq == cci_df->cci_min_freq) {
+ volt = dev_pm_opp_get_voltage(opp);
+ regulator_set_voltage(cci_df->proc_reg, volt, INT_MAX);
+ }
+ } else if (event == OPP_EVENT_DISABLE) {
+ }
+
+ return 0;
+}
+
+
static int mtk_cci_governor_get_target(struct devfreq *devfreq,
unsigned long *freq)
{
struct cci_devfreq *cci_df;
struct dev_pm_opp *opp;
+ int ret;

cci_df = dev_get_drvdata(devfreq->dev.parent);

/* find available frequency */
opp = dev_pm_opp_find_freq_ceil_by_volt(devfreq->dev.parent,
cci_df->proc_reg_uV);
+ ret = PTR_ERR_OR_ZERO(opp);
+ if (ret) {
+ pr_err("%s[%d], cannot find opp with voltage=%d: %d\n",
+ __func__, __LINE__, cci_df->proc_reg_uV, ret);
+ return ret;
+ }
*freq = dev_pm_opp_get_freq(opp);

return 0;
@@ -87,9 +135,11 @@ static int mtk_cci_governor_event_handler(struct devfreq *devfreq,
int ret;
struct cci_devfreq *cci_df;
struct notifier_block *nb;
+ struct notifier_block *opp_nb;

cci_df = dev_get_drvdata(devfreq->dev.parent);
nb = &cci_df->nb;
+ opp_nb = &cci_df->opp_nb;

switch (event) {
case DEVFREQ_GOV_START:
@@ -100,6 +150,8 @@ static int mtk_cci_governor_event_handler(struct devfreq *devfreq,
if (ret)
pr_err("%s: failed to add governor: %d\n", __func__,
ret);
+ opp_nb->notifier_call = ccidevfreq_opp_notifier;
+ dev_pm_opp_register_notifier(devfreq->dev.parent, opp_nb);
break;

case DEVFREQ_GOV_STOP:
@@ -141,6 +193,8 @@ static int mtk_cci_devfreq_target(struct device *dev, unsigned long *freq,
return ret;
}

+ cci_df->freq = *freq;
+
return 0;
}

@@ -152,6 +206,8 @@ static int mtk_cci_devfreq_probe(struct platform_device *pdev)
{
struct device *cci_dev = &pdev->dev;
struct cci_devfreq *cci_df;
+ unsigned long freq, volt;
+ struct dev_pm_opp *opp;
int ret;

cci_df = devm_kzalloc(cci_dev, sizeof(*cci_df), GFP_KERNEL);
@@ -181,6 +237,13 @@ static int mtk_cci_devfreq_probe(struct platform_device *pdev)
return ret;
}

+ /* set voltage lower bound */
+ freq = 1;
+ opp = dev_pm_opp_find_freq_ceil(cci_dev, &freq);
+ cci_df->cci_min_freq = dev_pm_opp_get_freq(opp);
+ volt = dev_pm_opp_get_voltage(opp);
+ dev_pm_opp_put(opp);
+
platform_set_drvdata(pdev, cci_df);

cci_df->devfreq = devm_devfreq_add_device(cci_dev,
--
2.12.5