Commit 6a0712f6 authored by Viresh Kumar's avatar Viresh Kumar Committed by Rafael J. Wysocki

PM / OPP: Add dev_pm_opp_set_rate()

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: default avatarViresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: default avatarStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent d54974c2
......@@ -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)
{
......
......@@ -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)
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment