Commit c016baf7 authored by Rajendra Nayak's avatar Rajendra Nayak Committed by Rafael J. Wysocki
Browse files

PM: domains: Add support for 'required-opps' to set default perf state 



Some devices within power domains with performance states do not
support DVFS, but still need to vote on a default/static state
while they are active. They can express this using the 'required-opps'
property in device tree, which points to the phandle of the OPP
supported by the corresponding power-domains.

Add support to parse this information from DT and then set the
specified performance state during attach and drop it on detach.
runtime suspend/resume callbacks already have logic to drop/set
the vote as needed and should take care of dropping the default
perf state vote on runtime suspend and restore it back on runtime
resume.

Signed-off-by: default avatarRajendra Nayak <rnayak@codeaurora.org>
Reviewed-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 020d86fc

drivers/base/power/domain.c

+28 −2
Original line number Diff line number Diff line
@@ -2598,6 +2598,12 @@ static void genpd_dev_pm_detach(struct device *dev, bool power_off) 


	dev_dbg(dev, "removing from PM domain %s\n", pd->name);



	/* Drop the default performance state */

	if (dev_gpd_data(dev)->default_pstate) {

		dev_pm_genpd_set_performance_state(dev, 0);

		dev_gpd_data(dev)->default_pstate = 0;

	}



	for (i = 1; i < GENPD_RETRY_MAX_MS; i <<= 1) {

		ret = genpd_remove_device(pd, dev);

		if (ret != -EAGAIN)
@@ -2637,6 +2643,7 @@ static int __genpd_dev_pm_attach(struct device *dev, struct device *base_dev, 
{

	struct of_phandle_args pd_args;

	struct generic_pm_domain *pd;

	int pstate;

	int ret;



	ret = of_parse_phandle_with_args(dev->of_node, "power-domains",
@@ -2675,10 +2682,29 @@ static int __genpd_dev_pm_attach(struct device *dev, struct device *base_dev, 
		genpd_unlock(pd);

	}



	if (ret)

	if (ret) {

		genpd_remove_device(pd, dev);

		return -EPROBE_DEFER;

	}



	return ret ? -EPROBE_DEFER : 1;

	/* Set the default performance state */

	pstate = of_get_required_opp_performance_state(dev->of_node, index);

	if (pstate < 0 && pstate != -ENODEV) {

		ret = pstate;

		goto err;

	} else if (pstate > 0) {

		ret = dev_pm_genpd_set_performance_state(dev, pstate);

		if (ret)

			goto err;

		dev_gpd_data(dev)->default_pstate = pstate;

	}

	return 1;



err:

	dev_err(dev, "failed to set required performance state for power-domain %s: %d\n",

		pd->name, ret);

	genpd_remove_device(pd, dev);

	return ret;

}



/**

include/linux/pm_domain.h

+1 −0
Original line number Diff line number Diff line
@@ -198,6 +198,7 @@ struct generic_pm_domain_data { 
	struct notifier_block *power_nb;

	int cpu;

	unsigned int performance_state;

	unsigned int default_pstate;

	unsigned int rpm_pstate;

	ktime_t	next_wakeup;

	void *data;