Initial Contribution
msm-2.6.38: tag AU_LINUX_ANDROID_GINGERBREAD.02.03.04.00.142
Signed-off-by: Bryan Huntsman <bryanh@codeaurora.org>
diff --git a/arch/arm/mach-msm/clock-voter.c b/arch/arm/mach-msm/clock-voter.c
new file mode 100644
index 0000000..1c742b1
--- /dev/null
+++ b/arch/arm/mach-msm/clock-voter.c
@@ -0,0 +1,187 @@
+/*
+ * Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/err.h>
+#include <linux/spinlock.h>
+#include <linux/clk.h>
+
+#include "clock.h"
+#include "clock-voter.h"
+
+static DEFINE_SPINLOCK(voter_clk_lock);
+
+/* Aggregate the rate of clocks that are currently on. */
+static unsigned voter_clk_aggregate_rate(const struct clk *parent)
+{
+ struct clk *clk;
+ unsigned rate = 0;
+
+ list_for_each_entry(clk, &parent->children, siblings) {
+ struct clk_voter *v = to_clk_voter(clk);
+ if (v->enabled)
+ rate = max(v->rate, rate);
+ }
+ return rate;
+}
+
+static int voter_clk_set_rate(struct clk *clk, unsigned rate)
+{
+ int ret = 0;
+ unsigned long flags;
+ struct clk *clkp;
+ struct clk_voter *clkh, *v = to_clk_voter(clk);
+ unsigned cur_rate, new_rate, other_rate = 0;
+
+ spin_lock_irqsave(&voter_clk_lock, flags);
+
+ if (v->enabled) {
+ struct clk *parent = v->parent;
+
+ /*
+ * Get the aggregate rate without this clock's vote and update
+ * if the new rate is different than the current rate
+ */
+ list_for_each_entry(clkp, &parent->children, siblings) {
+ clkh = to_clk_voter(clkp);
+ if (clkh->enabled && clkh != v)
+ other_rate = max(clkh->rate, other_rate);
+ }
+
+ cur_rate = max(other_rate, v->rate);
+ new_rate = max(other_rate, rate);
+
+ if (new_rate != cur_rate) {
+ ret = clk_set_min_rate(parent, new_rate);
+ if (ret)
+ goto unlock;
+ }
+ }
+ v->rate = rate;
+unlock:
+ spin_unlock_irqrestore(&voter_clk_lock, flags);
+
+ return ret;
+}
+
+static int voter_clk_enable(struct clk *clk)
+{
+ int ret;
+ unsigned long flags;
+ unsigned cur_rate;
+ struct clk *parent;
+ struct clk_voter *v = to_clk_voter(clk);
+
+ spin_lock_irqsave(&voter_clk_lock, flags);
+ parent = v->parent;
+
+ /*
+ * Increase the rate if this clock is voting for a higher rate
+ * than the current rate.
+ */
+ cur_rate = voter_clk_aggregate_rate(parent);
+ if (v->rate > cur_rate) {
+ ret = clk_set_min_rate(parent, v->rate);
+ if (ret)
+ goto out;
+ }
+ v->enabled = true;
+out:
+ spin_unlock_irqrestore(&voter_clk_lock, flags);
+
+ return ret;
+}
+
+static void voter_clk_disable(struct clk *clk)
+{
+ unsigned long flags;
+ struct clk *parent;
+ struct clk_voter *v = to_clk_voter(clk);
+ unsigned cur_rate, new_rate;
+
+ spin_lock_irqsave(&voter_clk_lock, flags);
+ parent = v->parent;
+
+ /*
+ * Decrease the rate if this clock was the only one voting for
+ * the highest rate.
+ */
+ v->enabled = false;
+ new_rate = voter_clk_aggregate_rate(parent);
+ cur_rate = max(new_rate, v->rate);
+
+ if (new_rate < cur_rate)
+ clk_set_min_rate(parent, new_rate);
+
+ spin_unlock_irqrestore(&voter_clk_lock, flags);
+}
+
+static unsigned voter_clk_get_rate(struct clk *clk)
+{
+ unsigned rate;
+ unsigned long flags;
+ struct clk_voter *v = to_clk_voter(clk);
+
+ spin_lock_irqsave(&voter_clk_lock, flags);
+ rate = v->rate;
+ spin_unlock_irqrestore(&voter_clk_lock, flags);
+
+ return rate;
+}
+
+static int voter_clk_is_enabled(struct clk *clk)
+{
+ struct clk_voter *v = to_clk_voter(clk);
+ return v->enabled;
+}
+
+static long voter_clk_round_rate(struct clk *clk, unsigned rate)
+{
+ struct clk_voter *v = to_clk_voter(clk);
+ return clk_round_rate(v->parent, rate);
+}
+
+static int voter_clk_set_parent(struct clk *clk, struct clk *parent)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&voter_clk_lock, flags);
+ if (list_empty(&clk->siblings))
+ list_add(&clk->siblings, &parent->children);
+ spin_unlock_irqrestore(&voter_clk_lock, flags);
+
+ return 0;
+}
+
+static struct clk *voter_clk_get_parent(struct clk *clk)
+{
+ struct clk_voter *v = to_clk_voter(clk);
+ return v->parent;
+}
+
+static bool voter_clk_is_local(struct clk *clk)
+{
+ return true;
+}
+
+struct clk_ops clk_ops_voter = {
+ .enable = voter_clk_enable,
+ .disable = voter_clk_disable,
+ .set_rate = voter_clk_set_rate,
+ .set_min_rate = voter_clk_set_rate,
+ .get_rate = voter_clk_get_rate,
+ .is_enabled = voter_clk_is_enabled,
+ .round_rate = voter_clk_round_rate,
+ .set_parent = voter_clk_set_parent,
+ .get_parent = voter_clk_get_parent,
+ .is_local = voter_clk_is_local,
+};