| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-Id: <9cae44895bc9d424b10445b959ba91ee60c85867.1441972771.git.viresh.kumar@linaro.org>
Date: Fri, 11 Sep 2015 17:32:11 +0530
From: Viresh Kumar <viresh.kumar@...aro.org>
To: Rafael Wysocki <rjw@...ysocki.net>, nm@...com, sboyd@...eaurora.org
Cc: linaro-kernel@...ts.linaro.org, linux-pm@...r.kernel.org,
rob.herring@...aro.org, lee.jones@...aro.org,
Viresh Kumar <viresh.kumar@...aro.org>,
Bartlomiej Zolnierkiewicz <b.zolnierkie@...sung.com>,
Dmitry Torokhov <dtor@...omium.org>,
Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
Len Brown <len.brown@...el.com>,
linux-kernel@...r.kernel.org (open list),
Pavel Machek <pavel@....cz>
Subject: [PATCH 15/16] PM / OPP: Add dev_pm_opp_set_rate()
This adds a routine, dev_pm_opp_set_rate(), responsible for configuring
power-supplies and clock source for on an OPP.
The OPP is found by matching against the target_freq passed to the
routine. This shall replace similar code present in most of the OPP
users and help simplify them a lot.
Signed-off-by: Viresh Kumar <viresh.kumar@...aro.org>
---
drivers/base/power/opp/core.c | 152 ++++++++++++++++++++++++++++++++++++++++++
include/linux/pm_opp.h | 7 ++
2 files changed, 159 insertions(+)
diff --git a/drivers/base/power/opp/core.c b/drivers/base/power/opp/core.c
index 4ee0911b97ea..9fbc38222ca0 100644
--- a/drivers/base/power/opp/core.c
+++ b/drivers/base/power/opp/core.c
@@ -523,6 +523,158 @@ struct dev_pm_opp *dev_pm_opp_find_freq_floor(struct device *dev,
}
EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_floor);
+/*
+ * _set_opp_voltages() - Configure device supplies for an OPP
+ * @dev: device for which we do this operation
+ * @dev_opp: dev_opp for the device
+ * @opp: opp for getting supply voltage levels
+ *
+ * This is used to configure all the power supplies, used by the device, to the
+ * voltage levels specified by a particular OPP.
+ */
+static int _set_opp_voltages(struct device *dev, struct device_opp *dev_opp,
+ struct dev_pm_opp *opp)
+{
+ struct opp_supply *supply;
+ struct regulator *reg;
+ const char *name;
+ int count, ret;
+
+ /* Sum max latencies for all supplies */
+ for (count = 0; count < dev_opp->supply_count; count++) {
+ supply = &opp->supplies[count];
+ reg = dev_opp->regulators[count];
+ name = dev_opp->supply_names[count];
+
+ /* Regulator may not be available for device */
+ if (IS_ERR(reg)) {
+ dev_dbg(dev, "%s: skipping %s regulator: %ld\n",
+ __func__, name, PTR_ERR(reg));
+ continue;
+ }
+
+ dev_dbg(dev, "%s: Supply: %s, voltages (mV): %lu %lu %lu\n",
+ __func__, name, supply->u_volt_min, supply->u_volt,
+ supply->u_volt_max);
+
+ ret = regulator_set_voltage_triplet(reg, supply->u_volt_min,
+ supply->u_volt,
+ supply->u_volt_max);
+ if (ret) {
+ dev_err(dev, "%s: failed to set voltage for %s regulator (%lu %lu %lu mV): %d\n",
+ __func__, name, supply->u_volt_min,
+ supply->u_volt, supply->u_volt_max, ret);
+ return ret;
+ }
+ }
+
+ return 0;
+}
+
+/**
+ * dev_pm_opp_set_rate() - Configure new OPP based on frequency
+ * @dev: device for which we do this operation
+ * @target_freq: frequency to achieve
+ *
+ * This configures the power-supplies and clock source to the levels specified
+ * by the OPP corresponding to the target_freq. It takes all necessary locks
+ * required for the operation and the caller doesn't need to care about the rcu
+ * locks.
+ */
+int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq)
+{
+ struct device_opp *dev_opp;
+ struct dev_pm_opp *old_opp, *opp;
+ struct clk *clk;
+ unsigned long freq, old_freq;
+ int ret;
+
+ if (unlikely(!dev || !target_freq)) {
+ pr_err("%s: Invalid arguments dev=%p, freq=%lu\n", __func__,
+ dev, target_freq);
+ return -EINVAL;
+ }
+
+ dev_opp = _find_device_opp(dev);
+ if (IS_ERR(dev_opp)) {
+ dev_err(dev, "%s: device opp doesn't exist\n", __func__);
+ return PTR_ERR(dev_opp);
+ }
+
+ clk = dev_opp->clk;
+ if (IS_ERR(clk)) {
+ dev_err(dev, "%s: No clock available for the device\n",
+ __func__);
+ return -EINVAL;
+ }
+
+ freq = clk_round_rate(clk, target_freq);
+ if ((long)freq <= 0)
+ freq = target_freq;
+
+ old_freq = clk_get_rate(clk);
+
+ /* Return early if nothing to do */
+ if (old_freq == freq) {
+ dev_dbg(dev, "%s: old/new frequencies (%lu Hz) are same, nothing to do\n",
+ __func__, freq);
+ return 0;
+ }
+
+ rcu_read_lock();
+
+ old_opp = dev_pm_opp_find_freq_ceil(dev, &old_freq);
+ opp = dev_pm_opp_find_freq_ceil(dev, &freq);
+
+ if (IS_ERR(opp)) {
+ ret = PTR_ERR(opp);
+ dev_err(dev, "%s: failed to find OPP for freq %lu (%d)\n",
+ __func__, freq, ret);
+ goto unlock;
+ }
+
+ /* Scaling up? Scale voltage before frequency */
+ if (freq > old_freq) {
+ ret = _set_opp_voltages(dev, dev_opp, opp);
+ if (ret)
+ goto restore_voltage;
+ }
+
+ /* Change frequency */
+
+ dev_dbg(dev, "%s: switching OPP: %lu Hz --> %lu Hz\n",
+ __func__, old_freq, freq);
+
+ ret = clk_set_rate(clk, freq);
+ if (ret) {
+ dev_err(dev, "%s: failed to set clock rate: %d\n", __func__,
+ ret);
+ goto restore_voltage;
+ }
+
+ /* Scaling down? Scale voltage after frequency */
+ if (freq < old_freq) {
+ ret = _set_opp_voltages(dev, dev_opp, opp);
+ if (ret)
+ goto restore_freq;
+ }
+
+ goto unlock;
+
+restore_freq:
+ if (clk_set_rate(clk, old_freq))
+ dev_err(dev, "%s: failed to restore old-freq (%lu Hz)\n",
+ __func__, old_freq);
+restore_voltage:
+ /* This shouldn't harm if the voltages weren't updated earlier */
+ _set_opp_voltages(dev, dev_opp, old_opp);
+unlock:
+ rcu_read_unlock();
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_set_rate);
+
/* List-dev Helpers */
static void _kfree_list_dev_rcu(struct rcu_head *head)
{
diff --git a/include/linux/pm_opp.h b/include/linux/pm_opp.h
index e8aee03b974a..b0f71c0f333a 100644
--- a/include/linux/pm_opp.h
+++ b/include/linux/pm_opp.h
@@ -58,6 +58,7 @@ int dev_pm_opp_disable(struct device *dev, unsigned long freq);
struct srcu_notifier_head *dev_pm_opp_get_notifier(struct device *dev);
int dev_pm_opp_set_regulator(struct device *dev, const char *id);
+int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq);
#else
static inline unsigned long dev_pm_opp_get_voltage(struct dev_pm_opp *opp)
{
@@ -147,6 +148,12 @@ static inline int dev_pm_opp_set_regulator(struct device *dev, const char *id)
{
return -EINVAL;
}
+
+static inline int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq)
+{
+ return -EINVAL;
+}
+
#endif /* CONFIG_PM_OPP */
#if defined(CONFIG_PM_OPP) && defined(CONFIG_OF)
--
2.4.0
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists