diff options
Diffstat (limited to 'arch/arm/mach-imx/clk-gate2.c')
-rw-r--r-- | arch/arm/mach-imx/clk-gate2.c | 118 |
1 files changed, 118 insertions, 0 deletions
diff --git a/arch/arm/mach-imx/clk-gate2.c b/arch/arm/mach-imx/clk-gate2.c new file mode 100644 index 00000000000..3c1b8ff9a0a --- /dev/null +++ b/arch/arm/mach-imx/clk-gate2.c @@ -0,0 +1,118 @@ +/* + * 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 int clk_gate2_enable(struct clk_hw *hw) +{ + struct clk_gate *gate = to_clk_gate(hw); + u32 reg; + unsigned long flags = 0; + + if (gate->lock) + spin_lock_irqsave(gate->lock, flags); + + reg = readl(gate->reg); + reg |= 3 << gate->bit_idx; + writel(reg, gate->reg); + + if (gate->lock) + spin_unlock_irqrestore(gate->lock, flags); + + return 0; +} + +static void clk_gate2_disable(struct clk_hw *hw) +{ + struct clk_gate *gate = to_clk_gate(hw); + u32 reg; + unsigned long flags = 0; + + if (gate->lock) + spin_lock_irqsave(gate->lock, flags); + + reg = readl(gate->reg); + reg &= ~(3 << gate->bit_idx); + writel(reg, gate->reg); + + if (gate->lock) + spin_unlock_irqrestore(gate->lock, flags); +} + +static int clk_gate2_is_enabled(struct clk_hw *hw) +{ + u32 reg; + struct clk_gate *gate = to_clk_gate(hw); + + reg = readl(gate->reg); + + if (((reg >> gate->bit_idx) & 3) == 3) + return 1; + + return 0; +} + +static struct clk_ops clk_gate2_ops = { + .enable = clk_gate2_enable, + .disable = clk_gate2_disable, + .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) +{ + struct clk_gate *gate; + struct clk *clk; + struct clk_init_data init; + + gate = kzalloc(sizeof(struct clk_gate), GFP_KERNEL); + if (!gate) + return ERR_PTR(-ENOMEM); + + /* struct clk_gate assignments */ + gate->reg = reg; + gate->bit_idx = bit_idx; + gate->flags = clk_gate2_flags; + gate->lock = lock; + + 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(clk); + + return clk; +} |