diff mbox

[06/17] PM / OPP: Parse clock-latency and voltage-tolerance for v1 bindings

Message ID 25cb4d7e9169815448193bd93305fae31a83792c.1450777582.git.viresh.kumar@linaro.org
State New
Headers show

Commit Message

Viresh Kumar Dec. 22, 2015, 10:16 a.m. UTC
V2 bindings have better support for clock-latency and voltage-tolerance
and doesn't need special care. To use callbacks, like
dev_pm_opp_get_max_{transition|volt}_latency(), irrespective of the
bindings, the core needs to know clock-latency/voltage-tolerance for the
earlier bindings.

This patch reads clock-latency/voltage-tolerance from the device node,
irrespective of the bindings (to keep it simple) and use them only for
V1 bindings.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

---
 drivers/base/power/opp/core.c | 20 ++++++++++++++++++++
 drivers/base/power/opp/opp.h  |  6 ++++++
 2 files changed, 26 insertions(+)

-- 
2.7.0.rc1.186.g94414c4

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Comments

Viresh Kumar Jan. 12, 2016, 5:14 a.m. UTC | #1
On 11-01-16, 17:29, Stephen Boyd wrote:
> On 12/22, Viresh Kumar wrote:

> > @@ -580,6 +581,21 @@ static struct device_opp *_add_device_opp_reg(struct device *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;


This is u64 type variable, but we are reading a 32 bit value from DT
and so wrote it that way.

> > +		of_property_read_u32(np, "voltage-tolerance",

> > +				     &dev_opp->voltage_tolerance_v1);


And this is u32 type.

> Why do we conditionalize the assignment for clock latency but not

> for voltage tolerance?


Nothing more than what I described earlier.

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Viresh Kumar Jan. 13, 2016, 5:35 a.m. UTC | #2
On 12-01-16, 16:36, Stephen Boyd wrote:
> On 01/12, Viresh Kumar wrote:

> > On 11-01-16, 17:29, Stephen Boyd wrote:

> > > On 12/22, Viresh Kumar wrote:

> > > > @@ -580,6 +581,21 @@ static struct device_opp *_add_device_opp_reg(struct device *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;

> > 

> > This is u64 type variable, but we are reading a 32 bit value from DT

> > and so wrote it that way.

> > 

> > > > +		of_property_read_u32(np, "voltage-tolerance",

> > > > +				     &dev_opp->voltage_tolerance_v1);

> > 

> > And this is u32 type.

> > 

> > > Why do we conditionalize the assignment for clock latency but not

> > > for voltage tolerance?

> > 

> > Nothing more than what I described earlier.

> > 

> 

> Ok.


Should I consider that an Reviewed-by ?

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diff mbox

Patch

diff --git a/drivers/base/power/opp/core.c b/drivers/base/power/opp/core.c
index 5746993aa71d..1bb09138cdae 100644
--- a/drivers/base/power/opp/core.c
+++ b/drivers/base/power/opp/core.c
@@ -563,6 +563,7 @@  static struct device_opp *_add_device_opp_reg(struct device *dev,
 {
 	struct device_opp *dev_opp;
 	struct device_list_opp *list_dev;
+	struct device_node *np;
 
 	/*
 	 * Allocate a new device OPP table. In the infrequent case where a new
@@ -580,6 +581,21 @@  static struct device_opp *_add_device_opp_reg(struct device *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);
+	}
+
 	dev_opp->regulator = regulator_get_optional(dev, name);
 	if (IS_ERR(dev_opp->regulator))
 		dev_info(dev, "%s: no regulator (%s) found: %ld\n", __func__,
@@ -865,6 +881,7 @@  static int _opp_add_v1(struct device *dev, unsigned long freq, long u_volt,
 {
 	struct device_opp *dev_opp;
 	struct dev_pm_opp *new_opp;
+	unsigned long tol;
 	int ret;
 
 	/* Hold our list modification lock here */
@@ -878,7 +895,10 @@  static int _opp_add_v1(struct device *dev, unsigned long freq, long u_volt,
 
 	/* 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;
 
diff --git a/drivers/base/power/opp/opp.h b/drivers/base/power/opp/opp.h
index 08aae35ab8e0..a39347d8693f 100644
--- a/drivers/base/power/opp/opp.h
+++ b/drivers/base/power/opp/opp.h
@@ -139,6 +139,8 @@  struct device_list_opp {
  * @dentry:	debugfs dentry pointer of the real device directory (not links).
  * @dentry_name: Name of the real dentry.
  *
+ * @voltage_tolerance_v1: In percentage, for v1 bindings only.
+ *
  * This is an internal data structure maintaining the link to opps attached to
  * a device. This structure is not meant to be shared to users as it is
  * meant for book keeping and private to OPP library.
@@ -157,6 +159,10 @@  struct device_opp {
 
 	struct device_node *np;
 	unsigned long clock_latency_ns_max;
+
+	/* For backward compatibility with v1 bindings */
+	unsigned int voltage_tolerance_v1;
+
 	bool shared_opp;
 	struct dev_pm_opp *suspend_opp;