[PATCH V2 6/6] PM / OPP: Add support to parse domain-performance-state

Viresh Kumar
2017-02-09T03:48:28Z

PLEASE DO NOT APPLY THIS PATCH

It is only sent for completeness. It uses DT bindings which aren't
finalized yet.

Some platforms have the capability to configure the performance state of
their Power Domains. The performance levels are represented by positive
integer values, a lower value represents lower performance state.

This patch introduces code in the OPP core to parse
"domain-performance-state" property from the OPP nodes.

Either none or all OPP nodes in an OPP table shall have the property
set.

NOT-Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
drivers/base/power/opp/core.c | 75 ++++++++++++++++++++++++++++++++++++++++
drivers/base/power/opp/debugfs.c | 4 +++
drivers/base/power/opp/of.c | 44 +++++++++++++++++++++++
drivers/base/power/opp/opp.h | 12 +++++++
4 files changed, 135 insertions(+)

diff --git a/drivers/base/power/opp/core.c b/drivers/base/power/opp/core.c
index 91ec3232d630..b5bb5f8775dc 100644
--- a/drivers/base/power/opp/core.c
+++ b/drivers/base/power/opp/core.c
@@ -542,6 +542,63 @@ _generic_set_opp_clk_only(struct device *dev, struct clk *clk,
return ret;
}

+static int _update_pm_qos_request(struct device *dev,
+ struct dev_pm_qos_request *req,
+ unsigned int perf)
+{
+ int ret;
+
+ if (likely(dev_pm_qos_request_active(req)))
+ ret = dev_pm_qos_update_request(req, perf);
+ else
+ ret = dev_pm_qos_add_request(dev, req, DEV_PM_QOS_PERFORMANCE,
+ perf);
+
+ if (ret < 0)
+ return ret;
+
+ return 0;
+}
+
+static int _generic_set_opp_pd(struct device *dev, struct clk *clk,
+ struct dev_pm_qos_request *req,
+ unsigned long old_freq, unsigned long freq,
+ unsigned int old_perf, unsigned int new_perf)
+{
+ int ret;
+
+ /* Scaling up? Scale voltage before frequency */
+ if (freq > old_freq) {
+ ret = _update_pm_qos_request(dev, req, new_perf);
+ if (ret)
+ return ret;
+ }
+
+ /* Change frequency */
+ ret = _generic_set_opp_clk_only(dev, clk, old_freq, freq);
+ if (ret)
+ goto restore_perf;
+
+ /* Scaling down? Scale voltage after frequency */
+ if (freq < old_freq) {
+ ret = _update_pm_qos_request(dev, req, new_perf);
+ if (ret)
+ goto restore_freq;
+ }
+
+ return 0;
+
+restore_freq:
+ if (_generic_set_opp_clk_only(dev, clk, freq, old_freq))
+ dev_err(dev, "%s: failed to restore old-freq (%lu Hz)\n",
+ __func__, old_freq);
+restore_perf:
+ if (old_perf)
+ _update_pm_qos_request(dev, req, old_perf);
+
+ return ret;
+}
+
static int _generic_set_opp(struct dev_pm_set_opp_data *data)
{
struct dev_pm_opp_supply *old_supply = data->old_opp.supplies;
@@ -662,6 +719,21 @@ int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq)

regulators = opp_table->regulators;

+ /* Has power domains performance states */
+ if (opp_table->has_pd_perf_states) {
+ unsigned int old_perf = 0, new_perf;
+ struct dev_pm_qos_request *req = &opp_table->qos_request;
+
+ new_perf = opp->pd_perf_state;
+ if (!IS_ERR(old_opp))
+ old_perf = old_opp->pd_perf_state;
+
+ rcu_read_unlock();
+
+ return _generic_set_opp_pd(dev, clk, req, old_freq, freq,
+ old_perf, new_perf);
+ }
+
/* Only frequency scaling */
if (!regulators) {
ret = _generic_set_opp_clk_only(dev, clk, old_freq, freq);
@@ -807,6 +879,9 @@ static void _opp_table_kref_release(struct kref *kref)
struct opp_table *opp_table = container_of(kref, struct opp_table, kref);
struct opp_device *opp_dev;

+ if (dev_pm_qos_request_active(&opp_table->qos_request))
+ dev_pm_qos_remove_request(&opp_table->qos_request);
+
/* Release clk */
if (!IS_ERR(opp_table->clk))
clk_put(opp_table->clk);
diff --git a/drivers/base/power/opp/debugfs.c b/drivers/base/power/opp/debugfs.c
index 95f433db4ac7..264958ab3de9 100644
--- a/drivers/base/power/opp/debugfs.c
+++ b/drivers/base/power/opp/debugfs.c
@@ -104,6 +104,10 @@ 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_u32("power_domain_perf_state", S_IRUGO, d,
+ &opp->pd_perf_state))
+ return -ENOMEM;
+
if (!opp_debug_create_supplies(opp, opp_table, d))
return -ENOMEM;

diff --git a/drivers/base/power/opp/of.c b/drivers/base/power/opp/of.c
index 083b79fa0c62..438a6b59baed 100644
--- a/drivers/base/power/opp/of.c
+++ b/drivers/base/power/opp/of.c
@@ -310,6 +310,45 @@ static int _opp_add_static_v2(struct opp_table *opp_table, struct device *dev,
if (!of_property_read_u32(np, "clock-latency-ns", &val))
new_opp->clock_latency_ns = val;

+ /*
+ * Make sure that all information is present around domain power states
+ * and nothing is left out.
+ */
+ if (!of_property_read_u32(np, "domain-performance-state",
+ &new_opp->pd_perf_state)) {
+ if (!opp_table->has_pd) {
+ ret = -EINVAL;
+ dev_err(dev, "%s: OPP node can't have performance state as device doesn't have power-domain\n",
+ __func__);
+ goto free_opp;
+ }
+
+ if (!new_opp->pd_perf_state) {
+ ret = -EINVAL;
+ dev_err(dev, "%s: OPP node can't have performance state as 0\n",
+ __func__);
+ goto free_opp;
+ }
+
+ if (opp_table->has_pd_perf_states == -1) {
+ opp_table->has_pd_perf_states = 1;
+ } else if (!opp_table->has_pd_perf_states) {
+ ret = -EINVAL;
+ dev_err(dev, "%s: Not all OPP nodes have performance state\n",
+ __func__);
+ goto free_opp;
+ }
+ } else {
+ if (opp_table->has_pd_perf_states == -1) {
+ opp_table->has_pd_perf_states = 0;
+ } else if (opp_table->has_pd_perf_states) {
+ ret = -EINVAL;
+ dev_err(dev, "%s: Not all OPP nodes have performance state\n",
+ __func__);
+ goto free_opp;
+ }
+ }
+
ret = opp_parse_supplies(new_opp, dev, opp_table);
if (ret)
goto free_opp;
@@ -374,6 +413,11 @@ static int _of_add_opp_table_v2(struct device *dev, struct device_node *opp_np)
if (!opp_table)
return -ENOMEM;

+ if (of_find_property(dev->of_node, "power-domains", NULL)) {
+ opp_table->has_pd = true;
+ opp_table->has_pd_perf_states = -1;
+ }
+
/* We have opp-table node now, iterate over it and add OPPs */
for_each_available_child_of_node(opp_np, np) {
count++;
diff --git a/drivers/base/power/opp/opp.h b/drivers/base/power/opp/opp.h
index 166eef990599..41a2c0a67031 100644
--- a/drivers/base/power/opp/opp.h
+++ b/drivers/base/power/opp/opp.h
@@ -20,6 +20,7 @@
#include <linux/list.h>
#include <linux/limits.h>
#include <linux/pm_opp.h>
+#include <linux/pm_qos.h>
#include <linux/notifier.h>

struct clk;
@@ -58,6 +59,7 @@ extern struct list_head opp_tables;
* @dynamic: not-created from static DT entries.
* @turbo: true if turbo (boost) OPP
* @suspend: true if suspend OPP
+ * @pd_perf_state: Performance state of power domain
* @rate: Frequency in hertz
* @supplies: Power supplies voltage/current values
* @clock_latency_ns: Latency (in nanoseconds) of switching to this OPP's
@@ -76,6 +78,7 @@ struct dev_pm_opp {
bool dynamic;
bool turbo;
bool suspend;
+ unsigned int pd_perf_state;
unsigned long rate;

struct dev_pm_opp_supply *supplies;
@@ -137,6 +140,11 @@ enum opp_table_access {
* @regulator_count: Number of power supply regulators
* @set_opp: Platform specific set_opp callback
* @set_opp_data: Data to be passed to set_opp callback
+ * @has_pd: True if the device node contains power-domain property
+ * @has_pd_perf_states: Can have value of 0, 1 or -1. -1 means uninitialized
+ * state, 0 means that OPP nodes don't have perf states and 1 means that OPP
+ * nodes have perf states.
+ * @qos_request: Qos request.
* @dentry: debugfs dentry pointer of the real device directory (not links).
* @dentry_name: Name of the real dentry.
*
@@ -174,6 +182,10 @@ struct opp_table {
int (*set_opp)(struct dev_pm_set_opp_data *data);
struct dev_pm_set_opp_data *set_opp_data;

+ bool has_pd;
+ int has_pd_perf_states;
+ struct dev_pm_qos_request qos_request;
+
#ifdef CONFIG_DEBUG_FS
struct dentry *dentry;
char dentry_name[NAME_MAX];
--
2.7.1.410.g6faf27b