Hi Sibi,
On Tue, Jan 28, 2020 at 01:33:44AM +0530, 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 <sibis@xxxxxxxxxxxxxx>
> ---
> drivers/opp/core.c | 55 ++++++++++++++++++++++++++++++++++++++++++
> include/linux/pm_opp.h | 10 ++++++++
> 2 files changed, 65 insertions(+)
>
> diff --git a/drivers/opp/core.c b/drivers/opp/core.c
> index 9aa2a44a5d638..f241e83ec926a 100644
> --- a/drivers/opp/core.c
> +++ b/drivers/opp/core.c
> @@ -2503,6 +2503,61 @@ 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
The comment should mention that this is done for an OPP.
Maybe omit the 'find' part here and just say 'Update the voltage of
an OPP'?
> + * @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 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);
initialization is not needed
> + struct opp_table *opp_table;
> + unsigned long tol;
> + int ret = 0;
> +
> + /* Find the opp_table */
Drop the comment, it's obvious from the code.
> + opp_table = _find_opp_table(dev);
> + if (IS_ERR(opp_table)) {
> + ret = PTR_ERR(opp_table);
> + dev_err(dev, "%s: OPP table not found (%d)\n", __func__, ret);
> + return PTR_ERR(opp_table);
return ret;
> + }
> +
> + opp = dev_pm_opp_find_freq_exact(dev, freq, false);
> + if (IS_ERR(opp)) {
> + ret = PTR_ERR(opp);
> + goto put_table;
> + }
> +
> + mutex_lock(&opp_table->lock);
> +
> + /* update only if the opp is disabled */
> + if (opp->available) {
> + ret = -EBUSY;
> + goto unlock;
> + }
> +
> + 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;
.u_volt_max =
I suppose the assignments need to be done for all possible supplies,
i.e. 0 to (opp_table->regulator_count - 1).
