Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / arch / arm / mach-imx / clk-gate2.c

diff --git a/kernel/arch/arm/mach-imx/clk-gate2.c b/kernel/arch/arm/mach-imx/clk-gate2.c
new file mode 100644 (file)
index 0000000..8935bff
--- /dev/null
+++ b/kernel/arch/arm/mach-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;
+}