From e5fd91f1ef340da553f7a79da9540c3db711c937 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Tue, 8 Sep 2015 01:01:14 -0300 Subject: Linux-libre 4.2-gnu --- drivers/clk/imx/clk-gate2.c | 160 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 160 insertions(+) create mode 100644 drivers/clk/imx/clk-gate2.c (limited to 'drivers/clk/imx/clk-gate2.c') diff --git a/drivers/clk/imx/clk-gate2.c b/drivers/clk/imx/clk-gate2.c new file mode 100644 index 000000000..8935bff99 --- /dev/null +++ b/drivers/clk/imx/clk-gate2.c @@ -0,0 +1,160 @@ +/* + * Copyright (C) 2010-2011 Canonical Ltd + * Copyright (C) 2011-2012 Mike Turquette, Linaro Ltd + * + * 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 +#include +#include +#include +#include +#include +#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; +} -- cgit v1.2.3-54-g00ecf