OPP: Assert clk_count == 1 for single clk helpers

Many helpers can be safely called only for devices that have a single
clk associated with them. Assert the same for those routines.

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 e732f97..4675a00 100644 (file)
--- a/drivers/opp/core.c
+++ b/drivers/opp/core.c
@@ -97,6 +97,18 @@ struct opp_table *_find_opp_table(struct device *dev)
        return opp_table;
 }
 
+/*
+ * Returns true if multiple clocks aren't there, else returns false with WARN.
+ *
+ * We don't force clk_count == 1 here as there are users who don't have a clock
+ * representation in the OPP table and manage the clock configuration themselves
+ * in an platform specific way.
+ */
+static bool assert_single_clk(struct opp_table *opp_table)
+{
+       return !WARN_ON(opp_table->clk_count > 1);
+}
+
 /**
  * dev_pm_opp_get_voltage() - Gets the voltage corresponding to an opp
  * @opp:       opp for which voltage has to be returned for
@@ -181,6 +193,9 @@ unsigned long dev_pm_opp_get_freq(struct dev_pm_opp *opp)
                return 0;
        }
 
+       if (!assert_single_clk(opp->opp_table))
+               return 0;
+
        return opp->rates[0];
 }
 EXPORT_SYMBOL_GPL(dev_pm_opp_get_freq);
@@ -601,7 +616,8 @@ static struct dev_pm_opp *_find_key_floor(struct device *dev,
 struct dev_pm_opp *dev_pm_opp_find_freq_exact(struct device *dev,
                unsigned long freq, bool available)
 {
-       return _find_key_exact(dev, freq, 0, available, _read_freq, NULL);
+       return _find_key_exact(dev, freq, 0, available, _read_freq,
+                              assert_single_clk);
 }
 EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_exact);
 
@@ -609,7 +625,7 @@ static noinline struct dev_pm_opp *_find_freq_ceil(struct opp_table *opp_table,
                                                   unsigned long *freq)
 {
        return _opp_table_find_key_ceil(opp_table, freq, 0, true, _read_freq,
-                                       NULL);
+                                       assert_single_clk);
 }
 
 /**
@@ -633,7 +649,7 @@ static noinline struct dev_pm_opp *_find_freq_ceil(struct opp_table *opp_table,
 struct dev_pm_opp *dev_pm_opp_find_freq_ceil(struct device *dev,
                                             unsigned long *freq)
 {
-       return _find_key_ceil(dev, freq, 0, true, _read_freq, NULL);
+       return _find_key_ceil(dev, freq, 0, true, _read_freq, assert_single_clk);
 }
 EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_ceil);
 
@@ -658,7 +674,7 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_ceil);
 struct dev_pm_opp *dev_pm_opp_find_freq_floor(struct device *dev,
                                              unsigned long *freq)
 {
-       return _find_key_floor(dev, freq, 0, true, _read_freq, NULL);
+       return _find_key_floor(dev, freq, 0, true, _read_freq, assert_single_clk);
 }
 EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_floor);
 
@@ -1535,6 +1551,9 @@ void dev_pm_opp_remove(struct device *dev, unsigned long freq)
        if (IS_ERR(opp_table))
                return;
 
+       if (!assert_single_clk(opp_table))
+               goto put_table;
+
        mutex_lock(&opp_table->lock);
 
        list_for_each_entry(iter, &opp_table->opp_list, node) {
@@ -1556,6 +1575,7 @@ void dev_pm_opp_remove(struct device *dev, unsigned long freq)
                         __func__, freq);
        }
 
+put_table:
        /* Drop the reference taken by _find_opp_table() */
        dev_pm_opp_put_opp_table(opp_table);
 }
@@ -1882,6 +1902,9 @@ int _opp_add_v1(struct opp_table *opp_table, struct device *dev,
        unsigned long tol;
        int ret;
 
+       if (!assert_single_clk(opp_table))
+               return -EINVAL;
+
        new_opp = _opp_allocate(opp_table);
        if (!new_opp)
                return -ENOMEM;
@@ -2735,6 +2758,11 @@ static int _opp_set_availability(struct device *dev, unsigned long freq,
                return r;
        }
 
+       if (!assert_single_clk(opp_table)) {
+               r = -EINVAL;
+               goto put_table;
+       }
+
        mutex_lock(&opp_table->lock);
 
        /* Do we have the frequency? */
@@ -2806,6 +2834,11 @@ int dev_pm_opp_adjust_voltage(struct device *dev, unsigned long freq,
                return r;
        }
 
+       if (!assert_single_clk(opp_table)) {
+               r = -EINVAL;
+               goto put_table;
+       }
+
        mutex_lock(&opp_table->lock);
 
        /* Do we have the frequency? */
@@ -2837,11 +2870,11 @@ int dev_pm_opp_adjust_voltage(struct device *dev, unsigned long freq,
                                     opp);
 
        dev_pm_opp_put(opp);
-       goto adjust_put_table;
+       goto put_table;
 
 adjust_unlock:
        mutex_unlock(&opp_table->lock);
-adjust_put_table:
+put_table:
        dev_pm_opp_put_opp_table(opp_table);
        return r;
 }