1 files changed, 160 insertions, 0 deletions

diff --git a/drivers/clk/imx/clk-gate2.c b/drivers/clk/imx/clk-gate2.c
new file mode 100644
index 0000000..8935bff
--- /dev/null
+++ b/drivers/clk/imx/clk-gate2.c
@@ -0,0 +1,160 @@
+/*
+ * Copyright (C) 2010-2011 Canonical Ltd <jeremy.kerr@canonical.com>
+ * Copyright (C) 2011-2012 Mike Turquette, Linaro Ltd <mturquette@linaro.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Gated clock implementation
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+#include <linux/err.h>
+#include <linux/string.h>
+#include "clk.h"
+
+/**
+ * DOC: basic gatable clock which can gate and ungate it's ouput
+ *
+ * Traits of this clock:
+ * prepare - clk_(un)prepare only ensures parent is (un)prepared
+ * enable - clk_enable and clk_disable are functional & control gating
+ * rate - inherits rate from parent.  No clk_set_rate support
+ * parent - fixed parent.  No clk_set_parent support
+ */
+
+struct clk_gate2 {
+	struct clk_hw hw;
+	void __iomem	*reg;
+	u8		bit_idx;
+	u8		flags;
+	spinlock_t	*lock;
+	unsigned int	*share_count;
+};
+
+#define to_clk_gate2(_hw) container_of(_hw, struct clk_gate2, hw)
+
+static int clk_gate2_enable(struct clk_hw *hw)
+{
+	struct clk_gate2 *gate = to_clk_gate2(hw);
+	u32 reg;
+	unsigned long flags = 0;
+
+	spin_lock_irqsave(gate->lock, flags);
+
+	if (gate->share_count && (*gate->share_count)++ > 0)
+		goto out;
+
+	reg = readl(gate->reg);
+	reg |= 3 << gate->bit_idx;
+	writel(reg, gate->reg);
+
+out:
+	spin_unlock_irqrestore(gate->lock, flags);
+
+	return 0;
+}
+
+static void clk_gate2_disable(struct clk_hw *hw)
+{
+	struct clk_gate2 *gate = to_clk_gate2(hw);
+	u32 reg;
+	unsigned long flags = 0;
+
+	spin_lock_irqsave(gate->lock, flags);
+
+	if (gate->share_count) {
+		if (WARN_ON(*gate->share_count == 0))
+			goto out;
+		else if (--(*gate->share_count) > 0)
+			goto out;
+	}
+
+	reg = readl(gate->reg);
+	reg &= ~(3 << gate->bit_idx);
+	writel(reg, gate->reg);
+
+out:
+	spin_unlock_irqrestore(gate->lock, flags);
+}
+
+static int clk_gate2_reg_is_enabled(void __iomem *reg, u8 bit_idx)
+{
+	u32 val = readl(reg);
+
+	if (((val >> bit_idx) & 1) == 1)
+		return 1;
+
+	return 0;
+}
+
+static int clk_gate2_is_enabled(struct clk_hw *hw)
+{
+	struct clk_gate2 *gate = to_clk_gate2(hw);
+
+	return clk_gate2_reg_is_enabled(gate->reg, gate->bit_idx);
+}
+
+static void clk_gate2_disable_unused(struct clk_hw *hw)
+{
+	struct clk_gate2 *gate = to_clk_gate2(hw);
+	unsigned long flags = 0;
+	u32 reg;
+
+	spin_lock_irqsave(gate->lock, flags);
+
+	if (!gate->share_count || *gate->share_count == 0) {
+		reg = readl(gate->reg);
+		reg &= ~(3 << gate->bit_idx);
+		writel(reg, gate->reg);
+	}
+
+	spin_unlock_irqrestore(gate->lock, flags);
+}
+
+static struct clk_ops clk_gate2_ops = {
+	.enable = clk_gate2_enable,
+	.disable = clk_gate2_disable,
+	.disable_unused = clk_gate2_disable_unused,
+	.is_enabled = clk_gate2_is_enabled,
+};
+
+struct clk *clk_register_gate2(struct device *dev, const char *name,
+		const char *parent_name, unsigned long flags,
+		void __iomem *reg, u8 bit_idx,
+		u8 clk_gate2_flags, spinlock_t *lock,
+		unsigned int *share_count)
+{
+	struct clk_gate2 *gate;
+	struct clk *clk;
+	struct clk_init_data init;
+
+	gate = kzalloc(sizeof(struct clk_gate2), GFP_KERNEL);
+	if (!gate)
+		return ERR_PTR(-ENOMEM);
+
+	/* struct clk_gate2 assignments */
+	gate->reg = reg;
+	gate->bit_idx = bit_idx;
+	gate->flags = clk_gate2_flags;
+	gate->lock = lock;
+	gate->share_count = share_count;
+
+	init.name = name;
+	init.ops = &clk_gate2_ops;
+	init.flags = flags;
+	init.parent_names = parent_name ? &parent_name : NULL;
+	init.num_parents = parent_name ? 1 : 0;
+
+	gate->hw.init = &init;
+
+	clk = clk_register(dev, &gate->hw);
+	if (IS_ERR(clk))
+		kfree(gate);
+
+	return clk;
+}