From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rajendra Nayak Subject: Re: [PATCH RFC 1/4] OPP: Add and export helper to update voltage Date: Fri, 28 Jun 2019 13:50:45 +0530 Message-ID: References: <20190627133424.4980-1-sibis@codeaurora.org> <20190627133424.4980-2-sibis@codeaurora.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20190627133424.4980-2-sibis@codeaurora.org> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Sibi Sankar , viresh.kumar@linaro.org, nm@ti.com, sboyd@kernel.org, georgi.djakov@linaro.org Cc: agross@kernel.org, david.brown@linaro.org, robh+dt@kernel.org, mark.rutland@arm.com, rjw@rjwysocki.net, linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, saravanak@google.com List-Id: devicetree@vger.kernel.org On 6/27/2019 7:04 PM, Sibi Sankar wrote: > Add and export 'dev_pm_opp_update_voltage' to find and update voltage > of an opp for a given frequency. This will be useful to update the opps > with voltages read back from firmware. > > Signed-off-by: Sibi Sankar > --- > drivers/opp/core.c | 52 ++++++++++++++++++++++++++++++++++++++++++ > include/linux/pm_opp.h | 10 ++++++++ > 2 files changed, 62 insertions(+) > > diff --git a/drivers/opp/core.c b/drivers/opp/core.c > index 68551d6366e6b..c85c04dc2c7de 100644 > --- a/drivers/opp/core.c > +++ b/drivers/opp/core.c > @@ -2197,6 +2197,58 @@ int dev_pm_opp_disable(struct device *dev, unsigned long freq) > } > EXPORT_SYMBOL_GPL(dev_pm_opp_disable); > > +/** > + * dev_pm_opp_update_voltage() - Find and update voltage > + * @dev: device for which we do this operation > + * @freq: OPP frequency to update voltage > + * @u_volt: voltage requested for this opp > + * > + * Find and update voltage of a disabled opp corresponding to the given > + * frequency. This is useful only for devices with single power supply. > + * > + * Return: 0 if no modification was done OR modification was > + * successful or a negative error value. > + */ > +int dev_pm_opp_update_voltage(struct device *dev, unsigned long freq, > + unsigned long u_volt) > +{ > + struct dev_pm_opp *opp = ERR_PTR(-ENODEV); > + struct opp_table *opp_table; > + unsigned long tol; > + int ret = 0; > + > + opp = dev_pm_opp_find_freq_exact(dev, freq, false); > + if (IS_ERR(opp)) > + return PTR_ERR(opp); > + > + /* Find the opp_table */ > + opp_table = _find_opp_table(dev); maybe you should look for the opp_table first and then the opp? otherwise this check seems pretty redundant given the above call would have failed if the opp table did not exist. > + if (IS_ERR(opp_table)) { > + ret = PTR_ERR(opp_table); > + dev_err(dev, "%s: OPP table not found (%d)\n", __func__, ret); > + goto put_opp; > + } > + > + mutex_lock(&opp_table->lock); > + > + /* update only if the opp is disabled */ > + if (opp->available) > + goto unlock; should this throw a warning/error to indicate someone tried to update this at a wrong time? and perhaps return an error instead of success. > + > + tol = u_volt * opp_table->voltage_tolerance_v1 / 100; > + opp->supplies[0].u_volt_min = u_volt - tol; > + opp->supplies[0].u_volt = u_volt; > + opp->supplies[0].u_volt_min = u_volt + tol; > + > +unlock: > + mutex_unlock(&opp_table->lock); > + dev_pm_opp_put_opp_table(opp_table); > +put_opp: > + dev_pm_opp_put(opp); > + return ret; > +} > +EXPORT_SYMBOL_GPL(dev_pm_opp_update_voltage); > + > /** > * dev_pm_opp_register_notifier() - Register OPP notifier for the device > * @dev: Device for which notifier needs to be registered > diff --git a/include/linux/pm_opp.h b/include/linux/pm_opp.h > index 87fa09d93d8c2..a17c462974851 100644 > --- a/include/linux/pm_opp.h > +++ b/include/linux/pm_opp.h > @@ -130,6 +130,9 @@ int dev_pm_opp_enable(struct device *dev, unsigned long freq); > > int dev_pm_opp_disable(struct device *dev, unsigned long freq); > > +int dev_pm_opp_update_voltage(struct device *dev, unsigned long freq, > + unsigned long u_volt); > + > int dev_pm_opp_register_notifier(struct device *dev, struct notifier_block *nb); > int dev_pm_opp_unregister_notifier(struct device *dev, struct notifier_block *nb); > > @@ -261,6 +264,13 @@ static inline int dev_pm_opp_disable(struct device *dev, unsigned long freq) > return 0; > } > > +static inline int dev_pm_opp_update_voltage(struct device *dev, > + unsigned long freq, > + unsigned long u_volt) > +{ > + return 0; > +} > + > static inline int dev_pm_opp_register_notifier(struct device *dev, struct notifier_block *nb) > { > return -ENOTSUPP; > -- QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation