From: Viresh Kumar <viresh.kumar@linaro.org>
To: Rafael Wysocki <rjw@rjwysocki.net>
Cc: linaro-kernel@lists.linaro.org, linux-pm@vger.kernel.org,
Stephen Boyd <sboyd@codeaurora.org>,
nm@ti.com, Viresh Kumar <viresh.kumar@linaro.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Len Brown <len.brown@intel.com>,
linux-kernel@vger.kernel.org (open list),
Pavel Machek <pavel@ucw.cz>, Viresh Kumar <vireshk@kernel.org>
Subject: [PATCH V3 07/16] PM / OPP: Add dev_pm_opp_set_rate()
Date: Tue, 9 Feb 2016 10:30:39 +0530 [thread overview]
Message-ID: <f284be9717a3bd6c52a917c012947071cdb7f3b8.1454992186.git.viresh.kumar@linaro.org> (raw)
In-Reply-To: <cover.1454992186.git.viresh.kumar@linaro.org>
In-Reply-To: <cover.1454992186.git.viresh.kumar@linaro.org>
This adds a routine, dev_pm_opp_set_rate(), responsible for configuring
power-supply and clock source for 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@linaro.org>
---
drivers/base/power/opp/core.c | 176 ++++++++++++++++++++++++++++++++++++++++++
include/linux/pm_opp.h | 6 ++
2 files changed, 182 insertions(+)
diff --git a/drivers/base/power/opp/core.c b/drivers/base/power/opp/core.c
index 7d7749ce1ce4..ab711c2c3e00 100644
--- a/drivers/base/power/opp/core.c
+++ b/drivers/base/power/opp/core.c
@@ -529,6 +529,182 @@ struct dev_pm_opp *dev_pm_opp_find_freq_floor(struct device *dev,
}
EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_floor);
+/*
+ * The caller needs to ensure that device_opp (and hence the clk) isn't freed,
+ * while clk returned here is used.
+ */
+static struct clk *_get_opp_clk(struct device *dev)
+{
+ struct device_opp *dev_opp;
+ struct clk *clk;
+
+ rcu_read_lock();
+
+ dev_opp = _find_device_opp(dev);
+ if (IS_ERR(dev_opp)) {
+ dev_err(dev, "%s: device opp doesn't exist\n", __func__);
+ clk = ERR_CAST(dev_opp);
+ goto unlock;
+ }
+
+ clk = dev_opp->clk;
+ if (IS_ERR(clk))
+ dev_err(dev, "%s: No clock available for the device\n",
+ __func__);
+
+unlock:
+ rcu_read_unlock();
+ return clk;
+}
+
+static int _set_opp_voltage(struct device *dev, struct regulator *reg,
+ unsigned long u_volt, unsigned long u_volt_min,
+ unsigned long u_volt_max)
+{
+ int ret;
+
+ /* Regulator not available for device */
+ if (IS_ERR(reg)) {
+ dev_dbg(dev, "%s: regulator not available: %ld\n", __func__,
+ PTR_ERR(reg));
+ return 0;
+ }
+
+ dev_dbg(dev, "%s: voltages (mV): %lu %lu %lu\n", __func__, u_volt_min,
+ u_volt, u_volt_max);
+
+ ret = regulator_set_voltage_triplet(reg, u_volt_min, u_volt,
+ u_volt_max);
+ if (ret)
+ dev_err(dev, "%s: failed to set voltage (%lu %lu %lu mV): %d\n",
+ __func__, u_volt_min, u_volt, u_volt_max, ret);
+
+ return ret;
+}
+
+/**
+ * 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.
+ *
+ * Locking: This function takes rcu_read_lock().
+ */
+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 regulator *reg;
+ struct clk *clk;
+ unsigned long freq, old_freq;
+ unsigned long u_volt, u_volt_min, u_volt_max;
+ unsigned long ou_volt, ou_volt_min, ou_volt_max;
+ int ret;
+
+ if (unlikely(!target_freq)) {
+ dev_err(dev, "%s: Invalid target frequency %lu\n", __func__,
+ target_freq);
+ return -EINVAL;
+ }
+
+ clk = _get_opp_clk(dev);
+ if (IS_ERR(clk))
+ return PTR_ERR(clk);
+
+ 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();
+
+ dev_opp = _find_device_opp(dev);
+ if (IS_ERR(dev_opp)) {
+ dev_err(dev, "%s: device opp doesn't exist\n", __func__);
+ rcu_read_unlock();
+ return PTR_ERR(dev_opp);
+ }
+
+ old_opp = dev_pm_opp_find_freq_ceil(dev, &old_freq);
+ if (!IS_ERR(old_opp)) {
+ ou_volt = old_opp->u_volt;
+ ou_volt_min = old_opp->u_volt_min;
+ ou_volt_max = old_opp->u_volt_max;
+ } else {
+ dev_err(dev, "%s: failed to find current OPP for freq %lu (%ld)\n",
+ __func__, old_freq, PTR_ERR(old_opp));
+ }
+
+ 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);
+ rcu_read_unlock();
+ return ret;
+ }
+
+ u_volt = opp->u_volt;
+ u_volt_min = opp->u_volt_min;
+ u_volt_max = opp->u_volt_max;
+
+ reg = dev_opp->regulator;
+
+ rcu_read_unlock();
+
+ /* Scaling up? Scale voltage before frequency */
+ if (freq > old_freq) {
+ ret = _set_opp_voltage(dev, reg, u_volt, u_volt_min,
+ u_volt_max);
+ 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_voltage(dev, reg, u_volt, u_volt_min,
+ u_volt_max);
+ if (ret)
+ goto restore_freq;
+ }
+
+ return 0;
+
+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 even if the voltages weren't updated earlier */
+ if (!IS_ERR(old_opp))
+ _set_opp_voltage(dev, reg, ou_volt, ou_volt_min, ou_volt_max);
+
+ 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 59da3d9e11ea..cccaf4a29e9f 100644
--- a/include/linux/pm_opp.h
+++ b/include/linux/pm_opp.h
@@ -64,6 +64,7 @@ int dev_pm_opp_set_prop_name(struct device *dev, const char *name);
void dev_pm_opp_put_prop_name(struct device *dev);
int dev_pm_opp_set_regulator(struct device *dev, const char *name);
void dev_pm_opp_put_regulator(struct device *dev);
+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)
{
@@ -172,6 +173,11 @@ static inline int dev_pm_opp_set_regulator(struct device *dev, const char *name)
static inline void dev_pm_opp_put_regulator(struct device *dev) {}
+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)
--
2.7.1.370.gb2aa7f8
next prev parent reply other threads:[~2016-02-09 5:02 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <cover.1454992186.git.viresh.kumar@linaro.org>
2016-02-09 5:00 ` [PATCH V3 01/16] PM / OPP: get/put regulators from OPP core Viresh Kumar
2016-02-09 19:04 ` Stephen Boyd
2016-02-09 5:00 ` [PATCH V3 02/16] PM / OPP: Disable OPPs that aren't supported by the regulator Viresh Kumar
2016-02-09 5:00 ` [PATCH V3 03/16] PM / OPP: Introduce dev_pm_opp_get_max_volt_latency() Viresh Kumar
2016-02-09 19:04 ` Stephen Boyd
2016-02-09 5:00 ` [PATCH V3 04/16] PM / OPP: Introduce dev_pm_opp_get_max_transition_latency() Viresh Kumar
2016-02-09 5:00 ` [PATCH V3 05/16] PM / OPP: Parse clock-latency and voltage-tolerance for v1 bindings Viresh Kumar
2016-02-09 5:00 ` [PATCH V3 06/16] PM / OPP: Manage device clk Viresh Kumar
2016-02-09 5:00 ` Viresh Kumar [this message]
2016-02-09 19:06 ` [PATCH V3 07/16] PM / OPP: Add dev_pm_opp_set_rate() Stephen Boyd
2016-02-09 5:00 ` [PATCH V3 08/16] cpufreq: dt: Convert few pr_debug/err() calls to dev_dbg/err() Viresh Kumar
2016-02-09 5:00 ` [PATCH V3 09/16] cpufreq: dt: Rename 'need_update' to 'opp_v1' Viresh Kumar
2016-02-09 5:00 ` [PATCH V3 10/16] cpufreq: dt: OPP layers handles clock-latency for V1 bindings as well Viresh Kumar
2016-02-09 5:00 ` [PATCH V3 11/16] cpufreq: dt: Pass regulator name to the OPP core Viresh Kumar
2016-02-09 19:07 ` Stephen Boyd
2018-07-17 7:46 ` Geert Uytterhoeven
2018-07-18 5:50 ` Viresh Kumar
2018-07-18 7:09 ` Geert Uytterhoeven
2018-07-18 7:16 ` Viresh Kumar
2016-02-09 5:00 ` [PATCH V3 12/16] cpufreq: dt: Unsupported OPPs are already disabled Viresh Kumar
2016-02-09 5:00 ` [PATCH V3 13/16] cpufreq: dt: Reuse dev_pm_opp_get_max_transition_latency() Viresh Kumar
2016-02-09 5:00 ` [PATCH V3 14/16] cpufreq: dt: Use dev_pm_opp_set_rate() to switch frequency Viresh Kumar
2016-02-09 5:00 ` [PATCH V3 15/16] cpufreq: dt: No need to fetch voltage-tolerance Viresh Kumar
2016-02-09 5:00 ` [PATCH V3 16/16] cpufreq: dt: No need to allocate resources anymore Viresh Kumar
2016-02-09 19:09 ` Stephen Boyd
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