diff -drupN a/drivers/clk/ingenic/power-gate.c b/drivers/clk/ingenic/power-gate.c --- a/drivers/clk/ingenic/power-gate.c 1970-01-01 03:00:00.000000000 +0300 +++ b/drivers/clk/ingenic/power-gate.c 2022-06-09 05:02:28.000000000 +0300 @@ -0,0 +1,197 @@ +/* + * 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 "power-gate.h" + + +struct power_gate { + struct clk_hw hw; + void __iomem *reg; + u8 ctrl_bit; + u8 wait_bit; + u8 flags; + unsigned long power_flags; + spinlock_t *lock; + +}; + + +/** + * DOC: basic gatable clock which can gate and ungate it's output + * + * 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_power_gate(_hw) container_of(_hw, struct power_gate, hw) + +/* + * It works on following logic: + * + * For enabling clock, enable = 1 + * set2dis = 1 -> clear bit -> set = 0 + * set2dis = 0 -> set bit -> set = 1 + * + * For disabling clock, enable = 0 + * set2dis = 1 -> set bit -> set = 1 + * set2dis = 0 -> clear bit -> set = 0 + * + * So, result is always: enable xor set2dis. + */ +static int power_gate_is_enabled(struct clk_hw *hw) +{ + u32 reg; + struct power_gate *gate = to_power_gate(hw); + + reg = clk_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->wait_bit); + + reg &= BIT(gate->wait_bit); + + return reg ? 1 : 0; +} + +static void power_gate_endisable(struct clk_hw *hw, int enable) +{ + struct power_gate *gate = to_power_gate(hw); + int set = gate->flags & CLK_GATE_SET_TO_DISABLE ? 1 : 0; + unsigned long uninitialized_var(flags); + u32 reg; + + set ^= enable; + + if (gate->lock) + spin_lock_irqsave(gate->lock, flags); + else + __acquire(gate->lock); + + reg = clk_readl(gate->reg); + + if (set) + reg |= BIT(gate->ctrl_bit); + else + reg &= ~BIT(gate->ctrl_bit); + clk_writel(reg, gate->reg); + + if (gate->lock) + spin_unlock_irqrestore(gate->lock, flags); + else + __release(gate->lock); +} + +static int power_gate_enable(struct clk_hw *hw) +{ + struct power_gate *gate = to_power_gate(hw); + + power_gate_endisable(hw, 1); + + if (gate->power_flags & POWER_GATE_WAIT) { + while (!power_gate_is_enabled(hw)); + } + + return 0; +} + +static void power_gate_disable(struct clk_hw *hw) +{ + struct power_gate *gate = to_power_gate(hw); + + power_gate_endisable(hw, 0); + + if (gate->power_flags & POWER_GATE_WAIT) { + while (power_gate_is_enabled(hw)); + } +} + +const struct clk_ops power_gate_ops = { + .enable = power_gate_enable, + .disable = power_gate_disable, + .is_enabled = power_gate_is_enabled, +}; +EXPORT_SYMBOL_GPL(power_gate_ops); + +/** + * clk_register_gate - register a gate clock with the clock framework + * @dev: device that is registering this clock + * @name: name of this clock + * @parent_name: name of this clock's parent + * @flags: framework-specific flags for this clock + * @reg: register address to control gating of this clock + * @bit_idx: which bit in the register controls gating of this clock + * @clk_gate_flags: gate-specific flags for this clock + * @lock: shared register lock for this clock + */ +struct clk *power_register_gate(struct device *dev, const char *name, + const char *parent_name, unsigned long flags, + void __iomem *reg, u8 ctrl_bit, u8 wait_bit, + u8 clk_gate_flags, unsigned long power_flags, spinlock_t *lock) +{ + struct power_gate *gate; + struct clk *clk; + struct clk_init_data init; + + /* allocate the gate */ + gate = kzalloc(sizeof(*gate), GFP_KERNEL); + if (!gate) + return ERR_PTR(-ENOMEM); + + init.name = name; + init.ops = &power_gate_ops; + init.flags = flags | CLK_IS_BASIC; + init.parent_names = (parent_name ? &parent_name: NULL); + init.num_parents = (parent_name ? 1 : 0); + + /* struct power_gate assignments */ + gate->reg = reg; + gate->ctrl_bit = ctrl_bit; + gate->wait_bit = wait_bit; + gate->flags = clk_gate_flags; + gate->power_flags = power_flags; + gate->lock = lock; + gate->hw.init = &init; + + clk = clk_register(dev, &gate->hw); + + if (IS_ERR(clk)) + kfree(gate); + + return clk; +} +EXPORT_SYMBOL_GPL(power_register_gate); + +void power_unregister_gate(struct clk *clk) +{ + struct power_gate *gate; + struct clk_hw *hw; + + hw = __clk_get_hw(clk); + if (!hw) + return; + + gate = to_power_gate(hw); + + clk_unregister(clk); + kfree(gate); +} +EXPORT_SYMBOL_GPL(power_unregister_gate);