OPP: Make dev_pm_opp_set_opp() independent of frequency

dev_pm_opp_set_opp() can be called for any device, it may or may not
have a frequency value associated with it.

If a frequency value isn't available, we pass 0 to _set_opp(). Make it
optional instead by making _set_opp() accept a pointer instead, as the
frequency value is anyway available in the OPP. This makes
dev_pm_opp_set_opp() and _set_opp() completely independent of any
special key value.

Tested-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

diff --git a/drivers/opp/core.c b/drivers/opp/core.c
index 00d5911b20f8102b4a18c5308035f2c8ddae4abb..daabc810a1f95285a7696dd2b6bcf1b032d5e029 100644 (file)
--- a/drivers/opp/core.c
+++ b/drivers/opp/core.c
@@ -784,19 +784,33 @@ static int _set_opp_voltage(struct device *dev, struct regulator *reg,
        return ret;
 }
 
-static inline int _generic_set_opp_clk_only(struct device *dev, struct clk *clk,
-                                           unsigned long freq)
+static inline int _generic_set_opp_clk_only(struct device *dev,
+               struct opp_table *opp_table, struct dev_pm_opp *opp, void *data)
 {
+       unsigned long *target = data;
+       unsigned long freq;
        int ret;
 
        /* We may reach here for devices which don't change frequency */
-       if (IS_ERR(clk))
+       if (IS_ERR(opp_table->clk))
                return 0;
 
-       ret = clk_set_rate(clk, freq);
+       /* One of target and opp must be available */
+       if (target) {
+               freq = *target;
+       } else if (opp) {
+               freq = opp->rate;
+       } else {
+               WARN_ON(1);
+               return -EINVAL;
+       }
+
+       ret = clk_set_rate(opp_table->clk, freq);
        if (ret) {
                dev_err(dev, "%s: failed to set clock rate: %d\n", __func__,
                        ret);
+       } else {
+               opp_table->rate_clk_single = freq;
        }
 
        return ret;
@@ -990,7 +1004,7 @@ static int _disable_opp_table(struct device *dev, struct opp_table *opp_table)
 }
 
 static int _set_opp(struct device *dev, struct opp_table *opp_table,
-                   struct dev_pm_opp *opp, unsigned long freq)
+                   struct dev_pm_opp *opp, void *clk_data, bool forced)
 {
        struct dev_pm_opp *old_opp;
        int scaling_down, ret;
@@ -1005,15 +1019,14 @@ static int _set_opp(struct device *dev, struct opp_table *opp_table,
        old_opp = opp_table->current_opp;
 
        /* Return early if nothing to do */
-       if (old_opp == opp && opp_table->current_rate == freq &&
-           opp_table->enabled) {
+       if (!forced && old_opp == opp && opp_table->enabled) {
                dev_dbg(dev, "%s: OPPs are same, nothing to do\n", __func__);
                return 0;
        }
 
        dev_dbg(dev, "%s: switching OPP: Freq %lu -> %lu Hz, Level %u -> %u, Bw %u -> %u\n",
-               __func__, opp_table->current_rate, freq, old_opp->level,
-               opp->level, old_opp->bandwidth ? old_opp->bandwidth[0].peak : 0,
+               __func__, old_opp->rate, opp->rate, old_opp->level, opp->level,
+               old_opp->bandwidth ? old_opp->bandwidth[0].peak : 0,
                opp->bandwidth ? opp->bandwidth[0].peak : 0);
 
        scaling_down = _opp_compare_key(old_opp, opp);
@@ -1046,7 +1059,7 @@ static int _set_opp(struct device *dev, struct opp_table *opp_table,
                }
        }
 
-       ret = _generic_set_opp_clk_only(dev, opp_table->clk, freq);
+       ret = _generic_set_opp_clk_only(dev, opp_table, opp, clk_data);
        if (ret)
                return ret;
 
@@ -1082,7 +1095,6 @@ static int _set_opp(struct device *dev, struct opp_table *opp_table,
        /* Make sure current_opp doesn't get freed */
        dev_pm_opp_get(opp);
        opp_table->current_opp = opp;
-       opp_table->current_rate = freq;
 
        return ret;
 }
@@ -1103,6 +1115,7 @@ int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq)
        struct opp_table *opp_table;
        unsigned long freq = 0, temp_freq;
        struct dev_pm_opp *opp = NULL;
+       bool forced = false;
        int ret;
 
        opp_table = _find_opp_table(dev);
@@ -1120,7 +1133,8 @@ int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq)
                 * equivalent to a clk_set_rate()
                 */
                if (!_get_opp_count(opp_table)) {
-                       ret = _generic_set_opp_clk_only(dev, opp_table->clk, target_freq);
+                       ret = _generic_set_opp_clk_only(dev, opp_table, NULL,
+                                                       &target_freq);
                        goto put_opp_table;
                }
 
@@ -1141,12 +1155,22 @@ int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq)
                                __func__, freq, ret);
                        goto put_opp_table;
                }
+
+               /*
+                * An OPP entry specifies the highest frequency at which other
+                * properties of the OPP entry apply. Even if the new OPP is
+                * same as the old one, we may still reach here for a different
+                * value of the frequency. In such a case, do not abort but
+                * configure the hardware to the desired frequency forcefully.
+                */
+               forced = opp_table->rate_clk_single != target_freq;
        }
 
-       ret = _set_opp(dev, opp_table, opp, freq);
+       ret = _set_opp(dev, opp_table, opp, &target_freq, forced);
 
        if (target_freq)
                dev_pm_opp_put(opp);
+
 put_opp_table:
        dev_pm_opp_put_opp_table(opp_table);
        return ret;
@@ -1174,7 +1198,7 @@ int dev_pm_opp_set_opp(struct device *dev, struct dev_pm_opp *opp)
                return PTR_ERR(opp_table);
        }
 
-       ret = _set_opp(dev, opp_table, opp, opp ? opp->rate : 0);
+       ret = _set_opp(dev, opp_table, opp, NULL, false);
        dev_pm_opp_put_opp_table(opp_table);
 
        return ret;

diff --git a/drivers/opp/opp.h b/drivers/opp/opp.h
index e449828ffbf4586882beccd99f90481d1bd78d54..e481bdb594996e79ed960e0c7eb5c2720b58e104 100644 (file)
--- a/drivers/opp/opp.h
+++ b/drivers/opp/opp.h
@@ -159,7 +159,7 @@ enum opp_table_access {
  * @clock_latency_ns_max: Max clock latency in nanoseconds.
  * @parsed_static_opps: Count of devices for which OPPs are initialized from DT.
  * @shared_opp: OPP is shared between multiple devices.
- * @current_rate: Currently configured frequency.
+ * @rate_clk_single: Currently configured frequency for single clk.
  * @current_opp: Currently configured OPP for the table.
  * @suspend_opp: Pointer to OPP to be used during device suspend.
  * @genpd_virt_dev_lock: Mutex protecting the genpd virtual device pointers.
@@ -208,7 +208,7 @@ struct opp_table {
 
        unsigned int parsed_static_opps;
        enum opp_table_access shared_opp;
-       unsigned long current_rate;
+       unsigned long rate_clk_single;
        struct dev_pm_opp *current_opp;
        struct dev_pm_opp *suspend_opp;