#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#include <linux/clk.h>
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/device.h>
#include <linux/of.h>
#include <linux/export.h>
+#include <linux/regulator/consumer.h>
#include "opp.h"
}
EXPORT_SYMBOL_GPL(dev_pm_opp_get_max_clock_latency);
+/**
+ * dev_pm_opp_get_max_volt_latency() - Get max voltage latency in nanoseconds
+ * @dev: device for which we do this operation
+ *
+ * Return: This function returns the max voltage latency in nanoseconds.
+ *
+ * Locking: This function takes rcu_read_lock().
+ */
+unsigned long dev_pm_opp_get_max_volt_latency(struct device *dev)
+{
+ struct device_opp *dev_opp;
+ struct dev_pm_opp *opp;
+ struct regulator *reg;
+ unsigned long latency_ns = 0;
+ unsigned long min_uV = ~0, max_uV = 0;
+ int ret;
+
+ rcu_read_lock();
+
+ dev_opp = _find_device_opp(dev);
+ if (IS_ERR(dev_opp)) {
+ rcu_read_unlock();
+ return 0;
+ }
+
+ reg = dev_opp->regulator;
+ if (IS_ERR_OR_NULL(reg)) {
+ /* Regulator may not be required for device */
+ if (reg)
+ dev_err(dev, "%s: Invalid regulator (%ld)\n", __func__,
+ PTR_ERR(reg));
+ rcu_read_unlock();
+ return 0;
+ }
+
+ list_for_each_entry_rcu(opp, &dev_opp->opp_list, node) {
+ if (!opp->available)
+ continue;
+
+ if (opp->u_volt_min < min_uV)
+ min_uV = opp->u_volt_min;
+ if (opp->u_volt_max > max_uV)
+ max_uV = opp->u_volt_max;
+ }
+
+ rcu_read_unlock();
+
+ /*
+ * The caller needs to ensure that dev_opp (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;
+
+ return latency_ns;
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_get_max_volt_latency);
+
+/**
+ * dev_pm_opp_get_max_transition_latency() - Get max transition latency in
+ * nanoseconds
+ * @dev: device for which we do this operation
+ *
+ * Return: This function returns the max transition latency, in nanoseconds, to
+ * switch from one OPP to other.
+ *
+ * Locking: This function takes rcu_read_lock().
+ */
+unsigned long dev_pm_opp_get_max_transition_latency(struct device *dev)
+{
+ return dev_pm_opp_get_max_volt_latency(dev) +
+ dev_pm_opp_get_max_clock_latency(dev);
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_get_max_transition_latency);
+
/**
* dev_pm_opp_get_suspend_opp() - Get suspend opp
* @dev: device for which we do this operation
}
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)
{
{
struct device_opp *dev_opp;
struct device_list_opp *list_dev;
+ struct device_node *np;
+ int ret;
/* Check for existing list for 'dev' first */
dev_opp = _find_device_opp(dev);
return NULL;
}
+ /*
+ * Only required for backward compatibility with v1 bindings, but isn't
+ * harmful for other cases. And so we do it unconditionally.
+ */
+ np = of_node_get(dev->of_node);
+ if (np) {
+ u32 val;
+
+ if (!of_property_read_u32(np, "clock-latency", &val))
+ dev_opp->clock_latency_ns_max = val;
+ of_property_read_u32(np, "voltage-tolerance",
+ &dev_opp->voltage_tolerance_v1);
+ of_node_put(np);
+ }
+
+ /* Find clk for the device */
+ dev_opp->clk = clk_get(dev, NULL);
+ if (IS_ERR(dev_opp->clk)) {
+ ret = PTR_ERR(dev_opp->clk);
+ if (ret != -EPROBE_DEFER)
+ dev_dbg(dev, "%s: Couldn't find clock: %d\n", __func__,
+ ret);
+ }
+
srcu_init_notifier_head(&dev_opp->srcu_head);
INIT_LIST_HEAD(&dev_opp->opp_list);
if (dev_opp->prop_name)
return;
+ if (!IS_ERR_OR_NULL(dev_opp->regulator))
+ return;
+
+ /* Release clk */
+ if (!IS_ERR(dev_opp->clk))
+ clk_put(dev_opp->clk);
+
list_dev = list_first_entry(&dev_opp->dev_list, struct device_list_opp,
node);
return opp;
}
+static bool _opp_supported_by_regulators(struct dev_pm_opp *opp,
+ struct device_opp *dev_opp)
+{
+ struct regulator *reg = dev_opp->regulator;
+
+ if (!IS_ERR(reg) &&
+ !regulator_is_supported_voltage(reg, opp->u_volt_min,
+ opp->u_volt_max)) {
+ pr_warn("%s: OPP minuV: %lu maxuV: %lu, not supported by regulator\n",
+ __func__, opp->u_volt_min, opp->u_volt_max);
+ return false;
+ }
+
+ return true;
+}
+
static int _opp_add(struct device *dev, struct dev_pm_opp *new_opp,
struct device_opp *dev_opp)
{
dev_err(dev, "%s: Failed to register opp to debugfs (%d)\n",
__func__, ret);
+ if (!_opp_supported_by_regulators(new_opp, dev_opp)) {
+ new_opp->available = false;
+ dev_warn(dev, "%s: OPP not supported by regulators (%lu)\n",
+ __func__, new_opp->rate);
+ }
+
return 0;
}
{
struct device_opp *dev_opp;
struct dev_pm_opp *new_opp;
+ unsigned long tol;
int ret;
/* Hold our list modification lock here */
/* populate the opp table */
new_opp->rate = freq;
+ tol = u_volt * dev_opp->voltage_tolerance_v1 / 100;
new_opp->u_volt = u_volt;
+ new_opp->u_volt_min = u_volt - tol;
+ new_opp->u_volt_max = u_volt + tol;
new_opp->available = true;
new_opp->dynamic = dynamic;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_put_prop_name);
+/**
+ * dev_pm_opp_set_regulator() - Set regulator name for the device
+ * @dev: Device for which regulator name is being set.
+ * @name: Name of the regulator.
+ *
+ * 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.
+ *
+ * This must be called before any OPPs are initialized for the device.
+ *
+ * Locking: The internal device_opp and opp structures are RCU protected.
+ * Hence this function internally uses RCU updater strategy with mutex locks
+ * to keep the integrity of the internal data structures. Callers should ensure
+ * 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)
+{
+ struct device_opp *dev_opp;
+ struct regulator *reg;
+ int ret;
+
+ mutex_lock(&dev_opp_list_lock);
+
+ dev_opp = _add_device_opp(dev);
+ if (!dev_opp) {
+ ret = -ENOMEM;
+ goto unlock;
+ }
+
+ /* This should be called before OPPs are initialized */
+ if (WARN_ON(!list_empty(&dev_opp->opp_list))) {
+ ret = -EBUSY;
+ goto err;
+ }
+
+ /* Already have a regulator set */
+ if (WARN_ON(!IS_ERR_OR_NULL(dev_opp->regulator))) {
+ 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);
+ goto err;
+ }
+
+ dev_opp->regulator = reg;
+
+ mutex_unlock(&dev_opp_list_lock);
+ return 0;
+
+err:
+ _remove_device_opp(dev_opp);
+unlock:
+ mutex_unlock(&dev_opp_list_lock);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_set_regulator);
+
+/**
+ * dev_pm_opp_put_regulator() - Releases resources blocked for regulator
+ * @dev: Device for which regulator was set.
+ *
+ * Locking: The internal device_opp and opp structures are RCU protected.
+ * Hence this function internally uses RCU updater strategy with mutex locks
+ * to keep the integrity of the internal data structures. Callers should ensure
+ * 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)
+{
+ struct device_opp *dev_opp;
+
+ mutex_lock(&dev_opp_list_lock);
+
+ /* Check for existing list for 'dev' first */
+ dev_opp = _find_device_opp(dev);
+ if (IS_ERR(dev_opp)) {
+ dev_err(dev, "Failed to find dev_opp: %ld\n", PTR_ERR(dev_opp));
+ goto unlock;
+ }
+
+ if (IS_ERR_OR_NULL(dev_opp->regulator)) {
+ dev_err(dev, "%s: Doesn't have regulator set\n", __func__);
+ goto unlock;
+ }
+
+ /* Make sure there are no concurrent readers while updating dev_opp */
+ WARN_ON(!list_empty(&dev_opp->opp_list));
+
+ regulator_put(dev_opp->regulator);
+ dev_opp->regulator = ERR_PTR(-EINVAL);
+
+ /* Try freeing device_opp if this was the last blocking resource */
+ _remove_device_opp(dev_opp);
+
+unlock:
+ mutex_unlock(&dev_opp_list_lock);
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_put_regulator);
+
static bool _opp_is_supported(struct device *dev, struct device_opp *dev_opp,
struct device_node *np)
{
projects / karo-tx-linux.git / blobdiff