Re: [PATCH V2 5/8] PM / OPP: Add infrastructure to manage multiple regulators

Viresh Kumar
2016-10-24T03:35:27Z

On 21-10-16, 17:32, Dave Gerlach wrote:
> Hi,
> On 10/20/2016 03:44 AM, Viresh Kumar wrote:
> > This patch adds infrastructure to manage multiple regulators and updates
> > the only user (cpufreq-dt) of dev_pm_opp_set{put}_regulator().
> >
> > This is preparatory work for adding full support for devices with
> > multiple regulators.
> >
> > Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
> > ---
> > drivers/base/power/opp/core.c | 220 ++++++++++++++++++++++++++-------------
> > drivers/base/power/opp/debugfs.c | 48 +++++++--
> > drivers/base/power/opp/of.c | 102 +++++++++++++-----
> > drivers/base/power/opp/opp.h | 10 +-
> > drivers/cpufreq/cpufreq-dt.c | 9 +-
> > include/linux/pm_opp.h | 8 +-
> > 6 files changed, 276 insertions(+), 121 deletions(-)
> >
> > diff --git a/drivers/base/power/opp/core.c b/drivers/base/power/opp/core.c
> > index 37fad2eb0f47..45c70ce07864 100644
> > --- a/drivers/base/power/opp/core.c
> > +++ b/drivers/base/power/opp/core.c
> > @@ -93,6 +93,8 @@ struct opp_table *_find_opp_table(struct device *dev)
> > * Return: voltage in micro volt corresponding to the opp, else
> > * return 0
> > *
> > + * This is useful only for devices with single power supply.
> > + *
> > * Locking: This function must be called under rcu_read_lock(). opp is a rcu
> > * protected pointer. This means that opp which could have been fetched by
> > * opp_find_freq_{exact,ceil,floor} functions is valid as long as we are
> > @@ -112,7 +114,7 @@ unsigned long dev_pm_opp_get_voltage(struct dev_pm_opp *opp)
> > if (IS_ERR_OR_NULL(tmp_opp))
> > pr_err("%s: Invalid parameters\n", __func__);
> > else
> > - v = tmp_opp->supply.u_volt;
> > + v = tmp_opp->supplies[0].u_volt;
> >
> > return v;
> > }
> > @@ -222,10 +224,10 @@ unsigned long dev_pm_opp_get_max_volt_latency(struct device *dev)
> > {
> > struct opp_table *opp_table;
> > struct dev_pm_opp *opp;
> > - struct regulator *reg;
> > + struct regulator *reg, **regulators;
> > unsigned long latency_ns = 0;
> > - unsigned long min_uV = ~0, max_uV = 0;
> > - int ret;
> > + unsigned long *min_uV, *max_uV;
> > + int ret, size, i, count;
> >
> > rcu_read_lock();
> >
> > @@ -235,21 +237,44 @@ unsigned long dev_pm_opp_get_max_volt_latency(struct device *dev)
> > return 0;
> > }
> >
> > - reg = opp_table->regulator;
> > - if (IS_ERR(reg)) {
> > + count = opp_table->regulator_count;
> > +
> > + if (!count) {
> > /* Regulator may not be required for device */
> > rcu_read_unlock();
> > return 0;
> > }
> >
> > - list_for_each_entry_rcu(opp, &opp_table->opp_list, node) {
> > - if (!opp->available)
> > - continue;
> > + size = count * sizeof(*regulators);
> > + regulators = kmemdup(opp_table->regulators, size, GFP_KERNEL);
> > + if (!regulators) {
> > + rcu_read_unlock();
> > + return 0;
> > + }
> > +
> > + min_uV = kmalloc(count * (sizeof(*min_uV) + sizeof(*max_uV)),
> > + GFP_KERNEL);
> > + if (!min_uV) {
> > + kfree(regulators);
> > + rcu_read_unlock();
> > + return 0;
> > + }
> > +
> > + max_uV = min_uV + count;
> > +
> > + for (i = 0; i < count; i++) {
> > + min_uV[i] = ~0;
> > + max_uV[i] = 0;
> > +
> > + list_for_each_entry_rcu(opp, &opp_table->opp_list, node) {
> > + if (!opp->available)
> > + continue;
> >
> > - if (opp->supply.u_volt_min < min_uV)
> > - min_uV = opp->supply.u_volt_min;
> > - if (opp->supply.u_volt_max > max_uV)
> > - max_uV = opp->supply.u_volt_max;
> > + if (opp->supplies[i].u_volt_min < min_uV[i])
> > + min_uV[i] = opp->supplies[i].u_volt_min;
> > + if (opp->supplies[i].u_volt_max > max_uV[i])
> > + max_uV[i] = opp->supplies[i].u_volt_max;
> > + }
> > }
> >
> > rcu_read_unlock();
> > @@ -258,9 +283,14 @@ unsigned long dev_pm_opp_get_max_volt_latency(struct device *dev)
> > * The caller needs to ensure that opp_table (and hence the regulator)
> > * isn't freed, while we are executing this routine.
> > */
> > - ret = regulator_set_voltage_time(reg, min_uV, max_uV);
> > - if (ret > 0)
> > - latency_ns = ret * 1000;
> > + for (i = 0; reg = regulators[i], i < count; i++) {
> > + ret = regulator_set_voltage_time(reg, min_uV[i], max_uV[i]);
> > + if (ret > 0)
> > + latency_ns += ret * 1000;
> > + }
> > +
> > + kfree(min_uV);
> > + kfree(regulators);
> >
> > return latency_ns;
> > }
> > @@ -580,7 +610,7 @@ int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq)
> > {
> > struct opp_table *opp_table;
> > struct dev_pm_opp *old_opp, *opp;
> > - struct regulator *reg;
> > + struct regulator *reg = ERR_PTR(-ENXIO);
> > struct clk *clk;
> > unsigned long freq, old_freq;
> > struct dev_pm_opp_supply old_supply, new_supply;
> > @@ -633,14 +663,23 @@ int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq)
> > return ret;
> > }
> >
> > + if (opp_table->regulators) {
> > + /* This function only supports single regulator per device */
> > + if (WARN_ON(opp_table->regulator_count > 1)) {
> > + dev_err(dev, "multiple regulators not supported\n");
> > + rcu_read_unlock();
> > + return -EINVAL;
> > + }
> > +
> > + reg = opp_table->regulators[0];
> > + }
> > +
> > if (IS_ERR(old_opp))
> > old_supply.u_volt = 0;
> > else
> > - memcpy(&old_supply, &old_opp->supply, sizeof(old_supply));
> > + memcpy(&old_supply, old_opp->supplies, sizeof(old_supply));
> >
> > - memcpy(&new_supply, &opp->supply, sizeof(new_supply));
> > -
> > - reg = opp_table->regulator;
> > + memcpy(&new_supply, opp->supplies, sizeof(new_supply));
> >
> > rcu_read_unlock();
> >
> > @@ -764,9 +803,6 @@ static struct opp_table *_add_opp_table(struct device *dev)
> >
> > _of_init_opp_table(opp_table, dev);
> >
> > - /* Set regulator to a non-NULL error value */
> > - opp_table->regulator = ERR_PTR(-ENXIO);
> > -
> > /* Find clk for the device */
> > opp_table->clk = clk_get(dev, NULL);
> > if (IS_ERR(opp_table->clk)) {
> > @@ -815,7 +851,7 @@ static void _remove_opp_table(struct opp_table *opp_table)
> > if (opp_table->prop_name)
> > return;
> >
> > - if (!IS_ERR(opp_table->regulator))
> > + if (opp_table->regulators)
> > return;
> >
> > /* Release clk */
> > @@ -924,35 +960,49 @@ struct dev_pm_opp *_allocate_opp(struct device *dev,
> > struct opp_table **opp_table)
> > {
> > struct dev_pm_opp *opp;
> > + int count, supply_size;
> > + struct opp_table *table;
> >
> > - /* allocate new OPP node */
> > - opp = kzalloc(sizeof(*opp), GFP_KERNEL);
> > - if (!opp)
> > + table = _add_opp_table(dev);
> > + if (!table)
> > return NULL;
> >
> > - INIT_LIST_HEAD(&opp->node);
> > + /* Allocate space for at least one supply */
> > + count = table->regulator_count ? table->regulator_count : 1;
> > + supply_size = sizeof(*opp->supplies) * count;
> >
> > - *opp_table = _add_opp_table(dev);
> > - if (!*opp_table) {
> > - kfree(opp);
> > + /* allocate new OPP node + and supplies structures */
> > + opp = kzalloc(sizeof(*opp) + supply_size, GFP_KERNEL);
> > + if (!opp) {
> > + kfree(table);
> > return NULL;
> > }
> >
> > + opp->supplies = (struct dev_pm_opp_supply *)(opp + 1);
> > + INIT_LIST_HEAD(&opp->node);
> > +
> > + *opp_table = table;
> > +
> > return opp;
> > }
> >
> > static bool _opp_supported_by_regulators(struct dev_pm_opp *opp,
> > struct opp_table *opp_table)
> > {
> > - struct regulator *reg = opp_table->regulator;
> > -
> > - if (!IS_ERR(reg) &&
> > - !regulator_is_supported_voltage(reg, opp->supply.u_volt_min,
> > - opp->supply.u_volt_max)) {
> > - pr_warn("%s: OPP minuV: %lu maxuV: %lu, not supported by regulator\n",
> > - __func__, opp->supply.u_volt_min,
> > - opp->supply.u_volt_max);
> > - return false;
> > + struct regulator *reg;
> > + int i;
> > +
> > + for (i = 0; i < opp_table->regulator_count; i++) {
> > + reg = opp_table->regulators[i];
> > +
> > + if (!regulator_is_supported_voltage(reg,
> > + opp->supplies[i].u_volt_min,
> > + opp->supplies[i].u_volt_max)) {
> > + pr_warn("%s: OPP minuV: %lu maxuV: %lu, not supported by regulator\n",
> > + __func__, opp->supplies[i].u_volt_min,
> > + opp->supplies[i].u_volt_max);
> > + return false;
> > + }
> > }
> >
> > return true;
> > @@ -984,12 +1034,13 @@ int _opp_add(struct device *dev, struct dev_pm_opp *new_opp,
> >
> > /* Duplicate OPPs */
> > dev_warn(dev, "%s: duplicate OPPs detected. Existing: freq: %lu, volt: %lu, enabled: %d. New: freq: %lu, volt: %lu, enabled: %d\n",
> > - __func__, opp->rate, opp->supply.u_volt,
> > - opp->available, new_opp->rate, new_opp->supply.u_volt,
> > - new_opp->available);
> > + __func__, opp->rate, opp->supplies[0].u_volt,
> > + opp->available, new_opp->rate,
> > + new_opp->supplies[0].u_volt, new_opp->available);
> >
> > + /* Should we compare voltages for all regulators here ? */
> > return opp->available &&
> > - new_opp->supply.u_volt == opp->supply.u_volt ? 0 : -EEXIST;
> > + new_opp->supplies[0].u_volt == opp->supplies[0].u_volt ? 0 : -EEXIST;
> > }
> >
> > new_opp->opp_table = opp_table;
> > @@ -1056,9 +1107,9 @@ int _opp_add_v1(struct device *dev, unsigned long freq, long u_volt,
> > /* populate the opp table */
> > new_opp->rate = freq;
> > tol = u_volt * opp_table->voltage_tolerance_v1 / 100;
> > - new_opp->supply.u_volt = u_volt;
> > - new_opp->supply.u_volt_min = u_volt - tol;
> > - new_opp->supply.u_volt_max = u_volt + tol;
> > + new_opp->supplies[0].u_volt = u_volt;
> > + new_opp->supplies[0].u_volt_min = u_volt - tol;
> > + new_opp->supplies[0].u_volt_max = u_volt + tol;
> > new_opp->available = true;
> > new_opp->dynamic = dynamic;
> >
> > @@ -1303,12 +1354,14 @@ void dev_pm_opp_put_prop_name(struct device *dev)
> > EXPORT_SYMBOL_GPL(dev_pm_opp_put_prop_name);
> >
> > /**
> > - * dev_pm_opp_set_regulator() - Set regulator name for the device
> > + * dev_pm_opp_set_regulators() - Set regulator names for the device
> > * @dev: Device for which regulator name is being set.
> > - * @name: Name of the regulator.
> > + * @names: Array of pointers to the names of the regulator.
> > + * @count: Number of regulators.
> > *
> > * In order to support OPP switching, OPP layer needs to know the name of the
> > - * device's regulator, as the core would be required to switch voltages as well.
> > + * device's regulators, as the core would be required to switch voltages as
> > + * well.
> > *
> > * This must be called before any OPPs are initialized for the device.
> > *
> > @@ -1318,11 +1371,12 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_put_prop_name);
> > * that this function is *NOT* called under RCU protection or in contexts where
> > * mutex cannot be locked.
> > */
> > -int dev_pm_opp_set_regulator(struct device *dev, const char *name)
> > +int dev_pm_opp_set_regulators(struct device *dev, const char *names[],
> > + unsigned int count)
> > {
> > struct opp_table *opp_table;
> > struct regulator *reg;
> > - int ret;
> > + int ret, i;
> >
> > mutex_lock(&opp_table_lock);
> >
> > @@ -1338,26 +1392,43 @@ int dev_pm_opp_set_regulator(struct device *dev, const char *name)
> > goto err;
> > }
> >
> > - /* Already have a regulator set */
> > - if (WARN_ON(!IS_ERR(opp_table->regulator))) {
> > + /* Already have regulators set */
> > + if (WARN_ON(opp_table->regulators)) {
> > ret = -EBUSY;
> > goto err;
> > }
> > - /* Allocate the regulator */
> > - reg = regulator_get_optional(dev, name);
> > - if (IS_ERR(reg)) {
> > - ret = PTR_ERR(reg);
> > - if (ret != -EPROBE_DEFER)
> > - dev_err(dev, "%s: no regulator (%s) found: %d\n",
> > - __func__, name, ret);
> > +
> > + opp_table->regulators = kmalloc_array(count,
> > + sizeof(*opp_table->regulators),
> > + GFP_KERNEL);
> > + if (!opp_table->regulators)
> > goto err;
> > +
> > + for (i = 0; i < count; i++) {
> > + reg = regulator_get_optional(dev, names[i]);
> > + pr_info("%s: %d: %p: %s\n", __func__, __LINE__, reg, names[i]);
>
> Think this is leftover debug msg?

Yes.

> > + if (IS_ERR(reg)) {
> > + ret = PTR_ERR(reg);
> > + if (ret != -EPROBE_DEFER)
> > + dev_err(dev, "%s: regulator (%s) not found: %d\n",
> > + __func__, names[i], ret);
> > + goto free_regulators;
> > + }
> > +
> > + opp_table->regulators[i] = reg;
> > }
> >
> > - opp_table->regulator = reg;
> > + opp_table->regulator_count = count;
> >
> > mutex_unlock(&opp_table_lock);
> > return 0;
> >
> > +free_regulators:
> > + while (i != 0)
> > + regulator_put(opp_table->regulators[--i]);
> > +
> > + kfree(opp_table->regulators);
> > + opp_table->regulators = NULL;
> > err:
> > _remove_opp_table(opp_table);
> > unlock:
> > @@ -1365,11 +1436,11 @@ int dev_pm_opp_set_regulator(struct device *dev, const char *name)
> >
> > return ret;
> > }
> > -EXPORT_SYMBOL_GPL(dev_pm_opp_set_regulator);
> > +EXPORT_SYMBOL_GPL(dev_pm_opp_set_regulators);
> >
> > /**
> > - * dev_pm_opp_put_regulator() - Releases resources blocked for regulator
> > - * @dev: Device for which regulator was set.
> > + * dev_pm_opp_put_regulators() - Releases resources blocked for regulators
> > + * @dev: Device for which regulators were set.
> > *
> > * Locking: The internal opp_table and opp structures are RCU protected.
> > * Hence this function internally uses RCU updater strategy with mutex locks
> > @@ -1377,9 +1448,10 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_set_regulator);
> > * that this function is *NOT* called under RCU protection or in contexts where
> > * mutex cannot be locked.
> > */
> > -void dev_pm_opp_put_regulator(struct device *dev)
> > +void dev_pm_opp_put_regulators(struct device *dev)
> > {
> > struct opp_table *opp_table;
> > + int i;
> >
> > mutex_lock(&opp_table_lock);
> >
> > @@ -1391,16 +1463,20 @@ void dev_pm_opp_put_regulator(struct device *dev)
> > goto unlock;
> > }
> >
> > - if (IS_ERR(opp_table->regulator)) {
> > - dev_err(dev, "%s: Doesn't have regulator set\n", __func__);
> > + if (!opp_table->regulators) {
> > + dev_err(dev, "%s: Doesn't have regulators set\n", __func__);
> > goto unlock;
> > }
> >
> > /* Make sure there are no concurrent readers while updating opp_table */
> > WARN_ON(!list_empty(&opp_table->opp_list));
> >
> > - regulator_put(opp_table->regulator);
> > - opp_table->regulator = ERR_PTR(-ENXIO);
> > + for (i = opp_table->regulator_count - 1; i >= 0; i--)
> > + regulator_put(opp_table->regulators[i]);
> > +
> > + kfree(opp_table->regulators);
> > + opp_table->regulators = NULL;
> > + opp_table->regulator_count = 0;
> >
> > /* Try freeing opp_table if this was the last blocking resource */
> > _remove_opp_table(opp_table);
> > @@ -1408,7 +1484,7 @@ void dev_pm_opp_put_regulator(struct device *dev)
> > unlock:
> > mutex_unlock(&opp_table_lock);
> > }
> > -EXPORT_SYMBOL_GPL(dev_pm_opp_put_regulator);
> > +EXPORT_SYMBOL_GPL(dev_pm_opp_put_regulators);
> >
> > /**
> > * dev_pm_opp_add() - Add an OPP table from a table definitions
> > diff --git a/drivers/base/power/opp/debugfs.c b/drivers/base/power/opp/debugfs.c
> > index c897676ca35f..cb5e5fde3d39 100644
> > --- a/drivers/base/power/opp/debugfs.c
> > +++ b/drivers/base/power/opp/debugfs.c
> > @@ -34,6 +34,43 @@ void opp_debug_remove_one(struct dev_pm_opp *opp)
> > debugfs_remove_recursive(opp->dentry);
> > }
> >
> > +static bool opp_debug_create_supplies(struct dev_pm_opp *opp,
> > + struct opp_table *opp_table,
> > + struct dentry *pdentry)
> > +{
> > + struct dentry *d;
> > + int i = 0;
> > + char name[] = "supply-X"; /* support only 0-9 supplies */
> > +
> > + /* Always create at least supply-0 directory */
> > + do {
> > + name[7] = i + '0';
> > +
> > + /* Create per-opp directory */
> > + d = debugfs_create_dir(name, pdentry);
> > + if (!d)
> > + return false;
> > +
> > + if (!debugfs_create_ulong("u_volt_target", S_IRUGO, d,
> > + &opp->supplies[i].u_volt))
> > + return false;
> > +
> > + if (!debugfs_create_ulong("u_volt_min", S_IRUGO, d,
> > + &opp->supplies[i].u_volt_min))
> > + return false;
> > +
> > + if (!debugfs_create_ulong("u_volt_max", S_IRUGO, d,
> > + &opp->supplies[i].u_volt_max))
> > + return false;
> > +
> > + if (!debugfs_create_ulong("u_amp", S_IRUGO, d,
> > + &opp->supplies[i].u_amp))
> > + return false;
> > + } while (++i < opp_table->regulator_count);
> > +
> > + return true;
> > +}
> > +
> > int opp_debug_create_one(struct dev_pm_opp *opp, struct opp_table *opp_table)
> > {
> > struct dentry *pdentry = opp_table->dentry;
> > @@ -63,16 +100,7 @@ int opp_debug_create_one(struct dev_pm_opp *opp, struct opp_table *opp_table)
> > if (!debugfs_create_ulong("rate_hz", S_IRUGO, d, &opp->rate))
> > return -ENOMEM;
> >
> > - if (!debugfs_create_ulong("u_volt_target", S_IRUGO, d, &opp->supply.u_volt))
> > - return -ENOMEM;
> > -
> > - if (!debugfs_create_ulong("u_volt_min", S_IRUGO, d, &opp->supply.u_volt_min))
> > - return -ENOMEM;
> > -
> > - if (!debugfs_create_ulong("u_volt_max", S_IRUGO, d, &opp->supply.u_volt_max))
> > - return -ENOMEM;
> > -
> > - if (!debugfs_create_ulong("u_amp", S_IRUGO, d, &opp->supply.u_amp))
> > + if (!opp_debug_create_supplies(opp, opp_table, d))
> > return -ENOMEM;
> >
> > if (!debugfs_create_ulong("clock_latency_ns", S_IRUGO, d,
> > diff --git a/drivers/base/power/opp/of.c b/drivers/base/power/opp/of.c
> > index b7fcd0a1b58b..c857fb07a5bc 100644
> > --- a/drivers/base/power/opp/of.c
> > +++ b/drivers/base/power/opp/of.c
> > @@ -17,6 +17,7 @@
> > #include <linux/errno.h>
> > #include <linux/device.h>
> > #include <linux/of.h>
> > +#include <linux/slab.h>
> > #include <linux/export.h>
> >
> > #include "opp.h"
> > @@ -105,12 +106,13 @@ static bool _opp_is_supported(struct device *dev, struct opp_table *opp_table,
>
> Though not in the patch there's a comment to
>
> /* TODO: Support multiple regulators */
>
> in the file right above the below opp_parse_supplies function that can probably
> be removed as part of this patch.

Sure.

--
viresh