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Diffstat (limited to 'drivers/clk')
-rw-r--r--drivers/clk/clk.c199
1 files changed, 194 insertions, 5 deletions
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index e2ed078abd90..976f59e11f9a 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -67,6 +67,7 @@ struct clk_core {
unsigned long max_rate;
unsigned long accuracy;
int phase;
+ struct clk_duty duty;
struct hlist_head children;
struct hlist_node child_node;
struct hlist_head clks;
@@ -2401,6 +2402,172 @@ int clk_get_phase(struct clk *clk)
}
EXPORT_SYMBOL_GPL(clk_get_phase);
+static void clk_core_reset_duty_cycle_nolock(struct clk_core *core)
+{
+ /* Assume a default value of 50% */
+ core->duty.num = 1;
+ core->duty.den = 2;
+}
+
+static int clk_core_update_duty_cycle_parent_nolock(struct clk_core *core);
+
+static int clk_core_update_duty_cycle_nolock(struct clk_core *core)
+{
+ struct clk_duty *duty = &core->duty;
+ int ret = 0;
+
+ if (!core->ops->get_duty_cycle)
+ return clk_core_update_duty_cycle_parent_nolock(core);
+
+ ret = core->ops->get_duty_cycle(core->hw, duty);
+ if (ret)
+ goto reset;
+
+ /* Don't trust the clock provider too much */
+ if (duty->den == 0 || duty->num > duty->den) {
+ ret = -EINVAL;
+ goto reset;
+ }
+
+ return 0;
+
+reset:
+ clk_core_reset_duty_cycle_nolock(core);
+ return ret;
+}
+
+static int clk_core_update_duty_cycle_parent_nolock(struct clk_core *core)
+{
+ int ret = 0;
+
+ if (core->parent &&
+ core->flags & CLK_DUTY_CYCLE_PARENT) {
+ ret = clk_core_update_duty_cycle_nolock(core->parent);
+ memcpy(&core->duty, &core->parent->duty, sizeof(core->duty));
+ } else {
+ clk_core_reset_duty_cycle_nolock(core);
+ }
+
+ return ret;
+}
+
+static int clk_core_set_duty_cycle_parent_nolock(struct clk_core *core,
+ struct clk_duty *duty);
+
+static int clk_core_set_duty_cycle_nolock(struct clk_core *core,
+ struct clk_duty *duty)
+{
+ int ret;
+
+ lockdep_assert_held(&prepare_lock);
+
+ if (clk_core_rate_is_protected(core))
+ return -EBUSY;
+
+ trace_clk_set_duty_cycle(core, duty);
+
+ if (!core->ops->set_duty_cycle)
+ return clk_core_set_duty_cycle_parent_nolock(core, duty);
+
+ ret = core->ops->set_duty_cycle(core->hw, duty);
+ if (!ret)
+ memcpy(&core->duty, duty, sizeof(*duty));
+
+ trace_clk_set_duty_cycle_complete(core, duty);
+
+ return ret;
+}
+
+static int clk_core_set_duty_cycle_parent_nolock(struct clk_core *core,
+ struct clk_duty *duty)
+{
+ int ret = 0;
+
+ if (core->parent &&
+ core->flags & (CLK_DUTY_CYCLE_PARENT | CLK_SET_RATE_PARENT)) {
+ ret = clk_core_set_duty_cycle_nolock(core->parent, duty);
+ memcpy(&core->duty, &core->parent->duty, sizeof(core->duty));
+ }
+
+ return ret;
+}
+
+/**
+ * clk_set_duty_cycle - adjust the duty cycle ratio of a clock signal
+ * @clk: clock signal source
+ * @num: numerator of the duty cycle ratio to be applied
+ * @den: denominator of the duty cycle ratio to be applied
+ *
+ * Apply the duty cycle ratio if the ratio is valid and the clock can
+ * perform this operation
+ *
+ * Returns (0) on success, a negative errno otherwise.
+ */
+int clk_set_duty_cycle(struct clk *clk, unsigned int num, unsigned int den)
+{
+ int ret;
+ struct clk_duty duty;
+
+ if (!clk)
+ return 0;
+
+ /* sanity check the ratio */
+ if (den == 0 || num > den)
+ return -EINVAL;
+
+ duty.num = num;
+ duty.den = den;
+
+ clk_prepare_lock();
+
+ if (clk->exclusive_count)
+ clk_core_rate_unprotect(clk->core);
+
+ ret = clk_core_set_duty_cycle_nolock(clk->core, &duty);
+
+ if (clk->exclusive_count)
+ clk_core_rate_protect(clk->core);
+
+ clk_prepare_unlock();
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(clk_set_duty_cycle);
+
+static int clk_core_get_scaled_duty_cycle(struct clk_core *core,
+ unsigned int scale)
+{
+ struct clk_duty *duty = &core->duty;
+ int ret;
+
+ clk_prepare_lock();
+
+ ret = clk_core_update_duty_cycle_nolock(core);
+ if (!ret)
+ ret = mult_frac(scale, duty->num, duty->den);
+
+ clk_prepare_unlock();
+
+ return ret;
+}
+
+/**
+ * clk_get_scaled_duty_cycle - return the duty cycle ratio of a clock signal
+ * @clk: clock signal source
+ * @scale: scaling factor to be applied to represent the ratio as an integer
+ *
+ * Returns the duty cycle ratio of a clock node multiplied by the provided
+ * scaling factor, or negative errno on error.
+ */
+int clk_get_scaled_duty_cycle(struct clk *clk, unsigned int scale)
+{
+ if (!clk)
+ return 0;
+
+ return clk_core_get_scaled_duty_cycle(clk->core, scale);
+}
+EXPORT_SYMBOL_GPL(clk_get_scaled_duty_cycle);
+
/**
* clk_is_match - check if two clk's point to the same hardware clock
* @p: clk compared against q
@@ -2454,12 +2621,13 @@ static void clk_summary_show_one(struct seq_file *s, struct clk_core *c,
if (!c)
return;
- seq_printf(s, "%*s%-*s %7d %8d %8d %11lu %10lu %-3d\n",
+ seq_printf(s, "%*s%-*s %7d %8d %8d %11lu %10lu %5d %6d\n",
level * 3 + 1, "",
30 - level * 3, c->name,
c->enable_count, c->prepare_count, c->protect_count,
clk_core_get_rate(c), clk_core_get_accuracy(c),
- clk_core_get_phase(c));
+ clk_core_get_phase(c),
+ clk_core_get_scaled_duty_cycle(c, 100000));
}
static void clk_summary_show_subtree(struct seq_file *s, struct clk_core *c,
@@ -2481,9 +2649,9 @@ static int clk_summary_show(struct seq_file *s, void *data)
struct clk_core *c;
struct hlist_head **lists = (struct hlist_head **)s->private;
- seq_puts(s, " enable prepare protect \n");
- seq_puts(s, " clock count count count rate accuracy phase\n");
- seq_puts(s, "----------------------------------------------------------------------------------------\n");
+ seq_puts(s, " enable prepare protect duty\n");
+ seq_puts(s, " clock count count count rate accuracy phase cycle\n");
+ seq_puts(s, "---------------------------------------------------------------------------------------------\n");
clk_prepare_lock();
@@ -2510,6 +2678,8 @@ static void clk_dump_one(struct seq_file *s, struct clk_core *c, int level)
seq_printf(s, "\"rate\": %lu,", clk_core_get_rate(c));
seq_printf(s, "\"accuracy\": %lu,", clk_core_get_accuracy(c));
seq_printf(s, "\"phase\": %d", clk_core_get_phase(c));
+ seq_printf(s, "\"duty_cycle\": %u",
+ clk_core_get_scaled_duty_cycle(c, 100000));
}
static void clk_dump_subtree(struct seq_file *s, struct clk_core *c, int level)
@@ -2571,6 +2741,7 @@ static const struct {
ENTRY(CLK_SET_RATE_UNGATE),
ENTRY(CLK_IS_CRITICAL),
ENTRY(CLK_OPS_PARENT_ENABLE),
+ ENTRY(CLK_DUTY_CYCLE_PARENT),
#undef ENTRY
};
@@ -2609,6 +2780,17 @@ static int possible_parents_show(struct seq_file *s, void *data)
}
DEFINE_SHOW_ATTRIBUTE(possible_parents);
+static int clk_duty_cycle_show(struct seq_file *s, void *data)
+{
+ struct clk_core *core = s->private;
+ struct clk_duty *duty = &core->duty;
+
+ seq_printf(s, "%u/%u\n", duty->num, duty->den);
+
+ return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(clk_duty_cycle);
+
static void clk_debug_create_one(struct clk_core *core, struct dentry *pdentry)
{
struct dentry *root;
@@ -2627,6 +2809,8 @@ static void clk_debug_create_one(struct clk_core *core, struct dentry *pdentry)
debugfs_create_u32("clk_enable_count", 0444, root, &core->enable_count);
debugfs_create_u32("clk_protect_count", 0444, root, &core->protect_count);
debugfs_create_u32("clk_notifier_count", 0444, root, &core->notifier_count);
+ debugfs_create_file("clk_duty_cycle", 0444, root, core,
+ &clk_duty_cycle_fops);
if (core->num_parents > 1)
debugfs_create_file("clk_possible_parents", 0444, root, core,
@@ -2845,6 +3029,11 @@ static int __clk_core_init(struct clk_core *core)
core->phase = 0;
/*
+ * Set clk's duty cycle.
+ */
+ clk_core_update_duty_cycle_nolock(core);
+
+ /*
* Set clk's rate. The preferred method is to use .recalc_rate. For
* simple clocks and lazy developers the default fallback is to use the
* parent's rate. If a clock doesn't have a parent (or is orphaned)
generated by cgit v1.2.3 (git 2.39.0) at 2024-11-21 17:41:13 +0300