PM / OPP: Parse clock-latency and voltage-tolerance for v1 bindings

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>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/base/power/opp/core.c b/drivers/base/power/opp/core.c
index b0f5c72..4fafa73 100644 (file)
--- a/drivers/base/power/opp/core.c
+++ b/drivers/base/power/opp/core.c
@@ -582,6 +582,7 @@ static struct device_opp *_add_device_opp(struct device *dev)
 {
        struct device_opp *dev_opp;
        struct device_list_opp *list_dev;
+       struct device_node *np;
 
        /* Check for existing list for 'dev' first */
        dev_opp = _find_device_opp(dev);
@@ -604,6 +605,21 @@ static struct device_opp *_add_device_opp(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);
+       }
+
        srcu_init_notifier_head(&dev_opp->srcu_head);
        INIT_LIST_HEAD(&dev_opp->opp_list);
 
@@ -861,6 +877,7 @@ 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 */
@@ -874,7 +891,10 @@ 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 416293b..fe44beb 100644 (file)
--- a/drivers/base/power/opp/opp.h
+++ b/drivers/base/power/opp/opp.h
@@ -138,6 +138,8 @@ 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.
@@ -156,6 +158,10 @@ 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;