[PATCH 1/2] PM / OPP: Add support for 'boost' mode OPP
Thomas Abraham
ta.omasab at gmail.com
Tue Feb 4 10:59:26 EST 2014
On Tue, Feb 4, 2014 at 8:45 PM, Nishanth Menon <nm at ti.com> wrote:
> On 02/04/2014 03:41 AM, Thomas Abraham wrote:
>> From: Thomas Abraham <thomas.ab at samsung.com>
>>
>> Commit 6f19efc0 ("cpufreq: Add boost frequency support in core") adds
>> support for CPU boost mode. This patch adds support for finding available
>> boost OPPs from device tree and marking them as usable in boost mode.
>>
>> Cc: Nishanth Menon <nm at ti.com>
>> Cc: Lukasz Majewski <l.majewski at samsung.com>
>> Signed-off-by: Thomas Abraham <thomas.ab at samsung.com>
>> ---
>
> Why is a cpufreq feature being pushed on to OPP library? you can very
> well have a property boot-frequencies = < a b c > and be done with the
> job.
The boost-opp was not limited to be a cpu/cpufreq only feature. Any
device (such as a bus) which has OPPs and if it can support optional
boost OPPs, can utilize this feature. The boost OPPs also require a
voltage to be associated with the frequency and hence the binding
boost-frequencies would not be suffice. The code changes in this patch
also do not have anything that is cpufreq specific.
>
> I agree with Rob's comment that this is something we have to discuss
> in wider "add features to an OPP" discussion[1].
Okay. I have read through the discussion in [1]. Thanks for the link.
Assuming that the current OPP tuple format will not change, I do not
feel the code changes in this patch will be hinder the outcome of the
discussion in [1].
Regards,
Thomas.
>
>
> [1] http://marc.info/?t=139108946400001&r=1&w=2
>
>> drivers/base/power/opp.c | 69 +++++++++++++++++++++++++++++++++++++---------
>> 1 file changed, 56 insertions(+), 13 deletions(-)
>>
>> diff --git a/drivers/base/power/opp.c b/drivers/base/power/opp.c
>> index 2553867..de4d52d 100644
>> --- a/drivers/base/power/opp.c
>> +++ b/drivers/base/power/opp.c
>> @@ -62,6 +62,7 @@ struct dev_pm_opp {
>> struct list_head node;
>>
>> bool available;
>> + bool boost;
>> unsigned long rate;
>> unsigned long u_volt;
>>
>> @@ -380,10 +381,12 @@ struct dev_pm_opp *dev_pm_opp_find_freq_floor(struct device *dev,
>> EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_floor);
>>
>> /**
>> - * dev_pm_opp_add() - Add an OPP table from a table definitions
>> + * dev_pm_opp_add_flags() - Add an OPP to device OPP list with flags
>> * @dev: device for which we do this operation
>> * @freq: Frequency in Hz for this OPP
>> * @u_volt: Voltage in uVolts for this OPP
>> + * @available: initial availability of the OPP with adding it to the list.
>> + * @boost: availability of this opp in controller's boost operating mode.
>> *
>> * This function adds an opp definition to the opp list and returns status.
>> * The opp is made available by default and it can be controlled using
>> @@ -395,7 +398,8 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_floor);
>> * that this function is *NOT* called under RCU protection or in contexts where
>> * mutex cannot be locked.
>> */
>> -int dev_pm_opp_add(struct device *dev, unsigned long freq, unsigned long u_volt)
>> +static int dev_pm_opp_add_flags(struct device *dev, unsigned long freq,
>> + unsigned long u_volt, bool available, bool boost)
>> {
>> struct device_opp *dev_opp = NULL;
>> struct dev_pm_opp *opp, *new_opp;
>> @@ -441,7 +445,8 @@ int dev_pm_opp_add(struct device *dev, unsigned long freq, unsigned long u_volt)
>> new_opp->dev_opp = dev_opp;
>> new_opp->rate = freq;
>> new_opp->u_volt = u_volt;
>> - new_opp->available = true;
>> + new_opp->available = available;
>> + new_opp->boost = boost;
>>
>> /* Insert new OPP in order of increasing frequency */
>> head = &dev_opp->opp_list;
>> @@ -462,6 +467,27 @@ int dev_pm_opp_add(struct device *dev, unsigned long freq, unsigned long u_volt)
>> srcu_notifier_call_chain(&dev_opp->head, OPP_EVENT_ADD, new_opp);
>> return 0;
>> }
>> +
>> +/**
>> + * dev_pm_opp_add() - Add an OPP table from a table definitions
>> + * @dev: device for which we do this operation
>> + * @freq: Frequency in Hz for this OPP
>> + * @u_volt: Voltage in uVolts for this OPP
>> + *
>> + * This function adds an opp definition to the opp list and returns status.
>> + * The opp is made available by default and it can be controlled using
>> + * dev_pm_opp_enable/disable functions.
>> + *
>> + * Locking: The internal device_opp and opp structures are RCU protected.
>> + * Hence this function internally uses RCU updater strategy with mutex locks
>> + * to keep the integrity of the internal data structures. Callers should ensure
>> + * that this function is *NOT* called under RCU protection or in contexts where
>> + * mutex cannot be locked.
>> + */
>> +int dev_pm_opp_add(struct device *dev, unsigned long freq, unsigned long u_volt)
>> +{
>> + return dev_pm_opp_add_flags(dev, freq, u_volt, true, false);
>> +}
>> EXPORT_SYMBOL_GPL(dev_pm_opp_add);
>>
>> /**
>> @@ -651,7 +677,8 @@ int dev_pm_opp_init_cpufreq_table(struct device *dev,
>>
>> list_for_each_entry(opp, &dev_opp->opp_list, node) {
>> if (opp->available) {
>> - freq_table[i].driver_data = i;
>> + freq_table[i].driver_data =
>> + opp->boost ? CPUFREQ_BOOST_FREQ : i;
>> freq_table[i].frequency = opp->rate / 1000;
>> i++;
>> }
>> @@ -701,19 +728,14 @@ struct srcu_notifier_head *dev_pm_opp_get_notifier(struct device *dev)
>> }
>>
>> #ifdef CONFIG_OF
>> -/**
>> - * of_init_opp_table() - Initialize opp table from device tree
>> - * @dev: device pointer used to lookup device OPPs.
>> - *
>> - * Register the initial OPP table with the OPP library for given device.
>> - */
>> -int of_init_opp_table(struct device *dev)
>> +static int of_parse_opp_table(struct device *dev, const char *prop_name,
>> + bool boost)
>> {
>> const struct property *prop;
>> const __be32 *val;
>> int nr;
>>
>> - prop = of_find_property(dev->of_node, "operating-points", NULL);
>> + prop = of_find_property(dev->of_node, prop_name, NULL);
>> if (!prop)
>> return -ENODEV;
>> if (!prop->value)
>> @@ -734,7 +756,7 @@ int of_init_opp_table(struct device *dev)
>> unsigned long freq = be32_to_cpup(val++) * 1000;
>> unsigned long volt = be32_to_cpup(val++);
>>
>> - if (dev_pm_opp_add(dev, freq, volt)) {
>> + if (dev_pm_opp_add_flags(dev, freq, volt, true, boost)) {
>> dev_warn(dev, "%s: Failed to add OPP %ld\n",
>> __func__, freq);
>> continue;
>> @@ -744,5 +766,26 @@ int of_init_opp_table(struct device *dev)
>>
>> return 0;
>> }
>> +
>> +/**
>> + * of_init_opp_table() - Initialize opp table from device tree
>> + * @dev: device pointer used to lookup device OPPs.
>> + *
>> + * Register the initial OPP table with the OPP library for given device.
>> + * Additional "boost" operating points of the controller, if any, are
>> + * specified with "boost-opp" property.
>> + */
>> +int of_init_opp_table(struct device *dev)
>> +{
>> + int ret;
>> +
>> + ret = of_parse_opp_table(dev, "operating-points", false);
>> + if (!ret) {
>> + ret = of_parse_opp_table(dev, "boost-opp", true);
>> + if (ret == -ENODEV)
>> + ret = 0;
>> + }
>> + return ret;
>> +}
>> EXPORT_SYMBOL_GPL(of_init_opp_table);
>> #endif
>>
>
>
> --
> Regards,
> Nishanth Menon
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