diff options
author | Ingo Molnar <mingo@kernel.org> | 2012-04-14 13:18:27 +0200 |
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committer | Ingo Molnar <mingo@kernel.org> | 2012-04-14 13:19:04 +0200 |
commit | 6ac1ef482d7ae0c690f1640bf6eb818ff9a2d91e (patch) | |
tree | 021cc9f6b477146fcebe6f3be4752abfa2ba18a9 /drivers/clk/clk-gate.c | |
parent | 682968e0c425c60f0dde37977e5beb2b12ddc4cc (diff) | |
parent | a385ec4f11bdcf81af094c03e2444ee9b7fad2e5 (diff) |
Merge branch 'perf/core' into perf/uprobes
Merge in latest upstream (and the latest perf development tree),
to prepare for tooling changes, and also to pick up v3.4 MM
changes that the uprobes code needs to take care of.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'drivers/clk/clk-gate.c')
-rw-r--r-- | drivers/clk/clk-gate.c | 150 |
1 files changed, 150 insertions, 0 deletions
diff --git a/drivers/clk/clk-gate.c b/drivers/clk/clk-gate.c new file mode 100644 index 00000000000..b5902e2ef2f --- /dev/null +++ b/drivers/clk/clk-gate.c @@ -0,0 +1,150 @@ +/* + * 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> + +/** + * 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 + */ + +#define to_clk_gate(_hw) container_of(_hw, struct clk_gate, hw) + +static void clk_gate_set_bit(struct clk_gate *gate) +{ + u32 reg; + unsigned long flags = 0; + + if (gate->lock) + spin_lock_irqsave(gate->lock, flags); + + reg = readl(gate->reg); + reg |= BIT(gate->bit_idx); + writel(reg, gate->reg); + + if (gate->lock) + spin_unlock_irqrestore(gate->lock, flags); +} + +static void clk_gate_clear_bit(struct clk_gate *gate) +{ + u32 reg; + unsigned long flags = 0; + + if (gate->lock) + spin_lock_irqsave(gate->lock, flags); + + reg = readl(gate->reg); + reg &= ~BIT(gate->bit_idx); + writel(reg, gate->reg); + + if (gate->lock) + spin_unlock_irqrestore(gate->lock, flags); +} + +static int clk_gate_enable(struct clk_hw *hw) +{ + struct clk_gate *gate = to_clk_gate(hw); + + if (gate->flags & CLK_GATE_SET_TO_DISABLE) + clk_gate_clear_bit(gate); + else + clk_gate_set_bit(gate); + + return 0; +} +EXPORT_SYMBOL_GPL(clk_gate_enable); + +static void clk_gate_disable(struct clk_hw *hw) +{ + struct clk_gate *gate = to_clk_gate(hw); + + if (gate->flags & CLK_GATE_SET_TO_DISABLE) + clk_gate_set_bit(gate); + else + clk_gate_clear_bit(gate); +} +EXPORT_SYMBOL_GPL(clk_gate_disable); + +static int clk_gate_is_enabled(struct clk_hw *hw) +{ + u32 reg; + struct clk_gate *gate = to_clk_gate(hw); + + reg = readl(gate->reg); + + /* if a set bit disables this clk, flip it before masking */ + if (gate->flags & CLK_GATE_SET_TO_DISABLE) + reg ^= BIT(gate->bit_idx); + + reg &= BIT(gate->bit_idx); + + return reg ? 1 : 0; +} +EXPORT_SYMBOL_GPL(clk_gate_is_enabled); + +struct clk_ops clk_gate_ops = { + .enable = clk_gate_enable, + .disable = clk_gate_disable, + .is_enabled = clk_gate_is_enabled, +}; +EXPORT_SYMBOL_GPL(clk_gate_ops); + +struct clk *clk_register_gate(struct device *dev, const char *name, + const char *parent_name, unsigned long flags, + void __iomem *reg, u8 bit_idx, + u8 clk_gate_flags, spinlock_t *lock) +{ + struct clk_gate *gate; + struct clk *clk; + + gate = kzalloc(sizeof(struct clk_gate), GFP_KERNEL); + + if (!gate) { + pr_err("%s: could not allocate gated clk\n", __func__); + return NULL; + } + + /* struct clk_gate assignments */ + gate->reg = reg; + gate->bit_idx = bit_idx; + gate->flags = clk_gate_flags; + gate->lock = lock; + + if (parent_name) { + gate->parent[0] = kstrdup(parent_name, GFP_KERNEL); + if (!gate->parent[0]) + goto out; + } + + clk = clk_register(dev, name, + &clk_gate_ops, &gate->hw, + gate->parent, + (parent_name ? 1 : 0), + flags); + if (clk) + return clk; +out: + kfree(gate->parent[0]); + kfree(gate); + + return NULL; +} |