/* * linux/include/linux/clk-provider.h * * Copyright (c) 2010-2011 Jeremy Kerr * Copyright (C) 2011-2012 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. */ #ifndef __LINUX_CLK_PROVIDER_H #define __LINUX_CLK_PROVIDER_H #include #ifdef CONFIG_COMMON_CLK /* * flags used across common struct clk. these flags should only affect the * top-level framework. custom flags for dealing with hardware specifics * belong in struct clk_foo */ #define CLK_SET_RATE_GATE BIT(0) /* must be gated across rate change */ #define CLK_SET_PARENT_GATE BIT(1) /* must be gated across re-parent */ #define CLK_SET_RATE_PARENT BIT(2) /* propagate rate change up one level */ #define CLK_IGNORE_UNUSED BIT(3) /* do not gate even if unused */ #define CLK_IS_ROOT BIT(4) /* root clk, has no parent */ #define CLK_IS_BASIC BIT(5) /* Basic clk, can't do a to_clk_foo() */ #define CLK_GET_RATE_NOCACHE BIT(6) /* do not use the cached clk rate */ struct clk_hw; /** * struct clk_ops - Callback operations for hardware clocks; these are to * be provided by the clock implementation, and will be called by drivers * through the clk_* api. * * @prepare: Prepare the clock for enabling. This must not return until * the clock is fully prepared, and it's safe to call clk_enable. * This callback is intended to allow clock implementations to * do any initialisation that may sleep. Called with * prepare_lock held. * * @unprepare: Release the clock from its prepared state. This will typically * undo any work done in the @prepare callback. Called with * prepare_lock held. * * @is_prepared: Queries the hardware to determine if the clock is prepared. * This function is allowed to sleep. Optional, if this op is not * set then the prepare count will be used. * * @unprepare_unused: Unprepare the clock atomically. Only called from * clk_disable_unused for prepare clocks with special needs. * Called with prepare mutex held. This function may sleep. * * @enable: Enable the clock atomically. This must not return until the * clock is generating a valid clock signal, usable by consumer * devices. Called with enable_lock held. This function must not * sleep. * * @disable: Disable the clock atomically. Called with enable_lock held. * This function must not sleep. * * @is_enabled: Queries the hardware to determine if the clock is enabled. * This function must not sleep. Optional, if this op is not * set then the enable count will be used. * * @disable_unused: Disable the clock atomically. Only called from * clk_disable_unused for gate clocks with special needs. * Called with enable_lock held. This function must not * sleep. * * @recalc_rate Recalculate the rate of this clock, by querying hardware. The * parent rate is an input parameter. It is up to the caller to * ensure that the prepare_mutex is held across this call. * Returns the calculated rate. Optional, but recommended - if * this op is not set then clock rate will be initialized to 0. * * @round_rate: Given a target rate as input, returns the closest rate actually * supported by the clock. * * @get_parent: Queries the hardware to determine the parent of a clock. The * return value is a u8 which specifies the index corresponding to * the parent clock. This index can be applied to either the * .parent_names or .parents arrays. In short, this function * translates the parent value read from hardware into an array * index. Currently only called when the clock is initialized by * __clk_init. This callback is mandatory for clocks with * multiple parents. It is optional (and unnecessary) for clocks * with 0 or 1 parents. * * @set_parent: Change the input source of this clock; for clocks with multiple * possible parents specify a new parent by passing in the index * as a u8 corresponding to the parent in either the .parent_names * or .parents arrays. This function in affect translates an * array index into the value programmed into the hardware. * Returns 0 on success, -EERROR otherwise. * * @set_rate: Change the rate of this clock. The requested rate is specified * by the second argument, which should typically be the return * of .round_rate call. The third argument gives the parent rate * which is likely helpful for most .set_rate implementation. * Returns 0 on success, -EERROR otherwise. * * The clk_enable/clk_disable and clk_prepare/clk_unprepare pairs allow * implementations to split any work between atomic (enable) and sleepable * (prepare) contexts. If enabling a clock requires code that might sleep, * this must be done in clk_prepare. Clock enable code that will never be * called in a sleepable context may be implemented in clk_enable. * * Typically, drivers will call clk_prepare when a clock may be needed later * (eg. when a device is opened), and clk_enable when the clock is actually * required (eg. from an interrupt). Note that clk_prepare MUST have been * called before clk_enable. */ struct clk_ops { int (*prepare)(struct clk_hw *hw); void (*unprepare)(struct clk_hw *hw); int (*is_prepared)(struct clk_hw *hw); void (*unprepare_unused)(struct clk_hw *hw); int (*enable)(struct clk_hw *hw); void (*disable)(struct clk_hw *hw); int (*is_enabled)(struct clk_hw *hw); void (*disable_unused)(struct clk_hw *hw); unsigned long (*recalc_rate)(struct clk_hw *hw, unsigned long parent_rate); long (*round_rate)(struct clk_hw *hw, unsigned long, unsigned long *); int (*set_parent)(struct clk_hw *hw, u8 index); u8 (*get_parent)(struct clk_hw *hw); int (*set_rate)(struct clk_hw *hw, unsigned long, unsigned long); void (*init)(struct clk_hw *hw); }; /** * struct clk_init_data - holds init data that's common to all clocks and is * shared between the clock provider and the common clock framework. * * @name: clock name * @ops: operations this clock supports * @parent_names: array of string names for all possible parents * @num_parents: number of possible parents * @flags: framework-level hints and quirks */ struct clk_init_data { const char *name; const struct clk_ops *ops; const char **parent_names; u8 num_parents; unsigned long flags; }; /** * struct clk_hw - handle for traversing from a struct clk to its corresponding * hardware-specific structure. struct clk_hw should be declared within struct * clk_foo and then referenced by the struct clk instance that uses struct * clk_foo's clk_ops * * @clk: pointer to the struct clk instance that points back to this struct * clk_hw instance * * @init: pointer to struct clk_init_data that contains the init data shared * with the common clock framework. */ struct clk_hw { struct clk *clk; const struct clk_init_data *init; }; /* * DOC: Basic clock implementations common to many platforms * * Each basic clock hardware type is comprised of a structure describing the * clock hardware, implementations of the relevant callbacks in struct clk_ops, * unique flags for that hardware type, a registration function and an * alternative macro for static initialization */ /** * struct clk_fixed_rate - fixed-rate clock * @hw: handle between common and hardware-specific interfaces * @fixed_rate: constant frequency of clock */ struct clk_fixed_rate { struct clk_hw hw; unsigned long fixed_rate; u8 flags; }; extern const struct clk_ops clk_fixed_rate_ops; struct clk *clk_register_fixed_rate(struct device *dev, const char *name, const char *parent_name, unsigned long flags, unsigned long fixed_rate); void of_fixed_clk_setup(struct device_node *np); /** * struct clk_gate - gating clock * * @hw: handle between common and hardware-specific interfaces * @reg: register controlling gate * @bit_idx: single bit controlling gate * @flags: hardware-specific flags * @lock: register lock * * Clock which can gate its output. Implements .enable & .disable * * Flags: * CLK_GATE_SET_TO_DISABLE - by default this clock sets the bit at bit_idx to * enable the clock. Setting this flag does the opposite: setting the bit * disable the clock and clearing it enables the clock */ struct clk_gate { struct clk_hw hw; void __iomem *reg; u8 bit_idx; u8 flags; spinlock_t *lock; }; #define CLK_GATE_SET_TO_DISABLE BIT(0) extern const struct clk_ops 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_div_table { unsigned int val; unsigned int div; }; /** * struct clk_divider - adjustable divider clock * * @hw: handle between common and hardware-specific interfaces * @reg: register containing the divider * @shift: shift to the divider bit field * @width: width of the divider bit field * @table: array of value/divider pairs, last entry should have div = 0 * @lock: register lock * * Clock with an adjustable divider affecting its output frequency. Implements * .recalc_rate, .set_rate and .round_rate * * Flags: * CLK_DIVIDER_ONE_BASED - by default the divisor is the value read from the * register plus one. If CLK_DIVIDER_ONE_BASED is set then the divider is * the raw value read from the register, with the value of zero considered * invalid, unless CLK_DIVIDER_ALLOW_ZERO is set. * CLK_DIVIDER_POWER_OF_TWO - clock divisor is 2 raised to the value read from * the hardware register * CLK_DIVIDER_ALLOW_ZERO - Allow zero divisors. For dividers which have * CLK_DIVIDER_ONE_BASED set, it is possible to end up with a zero divisor. * Some hardware implementations gracefully handle this case and allow a * zero divisor by not modifying their input clock * (divide by one / bypass). */ struct clk_divider { struct clk_hw hw; void __iomem *reg; u8 shift; u8 width; u8 flags; const struct clk_div_table *table; spinlock_t *lock; }; #define CLK_DIVIDER_ONE_BASED BIT(0) #define CLK_DIVIDER_POWER_OF_TWO BIT(1) #define CLK_DIVIDER_ALLOW_ZERO BIT(2) extern const struct clk_ops clk_divider_ops; struct clk *clk_register_divider(struct device *dev, const char *name, const char *parent_name, unsigned long flags, void __iomem *reg, u8 shift, u8 width, u8 clk_divider_flags, spinlock_t *lock); struct clk *clk_register_divider_table(struct device *dev, const char *name, const char *parent_name, unsigned long flags, void __iomem *reg, u8 shift, u8 width, u8 clk_divider_flags, const struct clk_div_table *table, spinlock_t *lock); /** * struct clk_mux - multiplexer clock * * @hw: handle between common and hardware-specific interfaces * @reg: register controlling multiplexer * @shift: shift to multiplexer bit field * @width: width of mutliplexer bit field * @flags: hardware-specific flags * @lock: register lock * * Clock with multiple selectable parents. Implements .get_parent, .set_parent * and .recalc_rate * * Flags: * CLK_MUX_INDEX_ONE - register index starts at 1, not 0 * CLK_MUX_INDEX_BIT - register index is a single bit (power of two) */ struct clk_mux { struct clk_hw hw; void __iomem *reg; u32 *table; u32 mask; u8 shift; u8 flags; spinlock_t *lock; }; #define CLK_MUX_INDEX_ONE BIT(0) #define CLK_MUX_INDEX_BIT BIT(1) extern const struct clk_ops clk_mux_ops; struct clk *clk_register_mux(struct device *dev, const char *name, const char **parent_names, u8 num_parents, unsigned long flags, void __iomem *reg, u8 shift, u8 width, u8 clk_mux_flags, spinlock_t *lock); struct clk *clk_register_mux_table(struct device *dev, const char *name, const char **parent_names, u8 num_parents, unsigned long flags, void __iomem *reg, u8 shift, u32 mask, u8 clk_mux_flags, u32 *table, spinlock_t *lock); void of_fixed_factor_clk_setup(struct device_node *node); /** * struct clk_fixed_factor - fixed multiplier and divider clock * * @hw: handle between common and hardware-specific interfaces * @mult: multiplier * @div: divider * * Clock with a fixed multiplier and divider. The output frequency is the * parent clock rate divided by div and multiplied by mult. * Implements .recalc_rate, .set_rate and .round_rate */ struct clk_fixed_factor { struct clk_hw hw; unsigned int mult; unsigned int div; }; extern struct clk_ops clk_fixed_factor_ops; struct clk *clk_register_fixed_factor(struct device *dev, const char *name, const char *parent_name, unsigned long flags, unsigned int mult, unsigned int div); /*** * struct clk_composite - aggregate clock of mux, divider and gate clocks * * @hw: handle between common and hardware-specific interfaces * @mux_hw: handle between composite and hardware-specific mux clock * @rate_hw: handle between composite and hardware-specific rate clock * @gate_hw: handle between composite and hardware-specific gate clock * @mux_ops: clock ops for mux * @rate_ops: clock ops for rate * @gate_ops: clock ops for gate */ struct clk_composite { struct clk_hw hw; struct clk_ops ops; struct clk_hw *mux_hw; struct clk_hw *rate_hw; struct clk_hw *gate_hw; const struct clk_ops *mux_ops; const struct clk_ops *rate_ops; const struct clk_ops *gate_ops; }; struct clk *clk_register_composite(struct device *dev, const char *name, const char **parent_names, int num_parents, struct clk_hw *mux_hw, const struct clk_ops *mux_ops, struct clk_hw *rate_hw, const struct clk_ops *rate_ops, struct clk_hw *gate_hw, const struct clk_ops *gate_ops, unsigned long flags); /** * clk_register - allocate a new clock, register it and return an opaque cookie * @dev: device that is registering this clock * @hw: link to hardware-specific clock data * * clk_register is the primary interface for populating the clock tree with new * clock nodes. It returns a pointer to the newly allocated struct clk which * cannot be dereferenced by driver code but may be used in conjuction with the * rest of the clock API. In the event of an error clk_register will return an * error code; drivers must test for an error code after calling clk_register. */ struct clk *clk_register(struct device *dev, struct clk_hw *hw); struct clk *devm_clk_register(struct device *dev, struct clk_hw *hw); void clk_unregister(struct clk *clk); void devm_clk_unregister(struct device *dev, struct clk *clk); /* helper functions */ const char *__clk_get_name(struct clk *clk); struct clk_hw *__clk_get_hw(struct clk *clk); u8 __clk_get_num_parents(struct clk *clk); struct clk *__clk_get_parent(struct clk *clk); unsigned int __clk_get_enable_count(struct clk *clk); unsigned int __clk_get_prepare_count(struct clk *clk); unsigned long __clk_get_rate(struct clk *clk); unsigned long __clk_get_flags(struct clk *clk); bool __clk_is_prepared(struct clk *clk); bool __clk_is_enabled(struct clk *clk); struct clk *__clk_lookup(const char *name); /* * FIXME clock api without lock protection */ int __clk_prepare(struct clk *clk); void __clk_unprepare(struct clk *clk); void __clk_reparent(struct clk *clk, struct clk *new_parent); unsigned long __clk_round_rate(struct clk *clk, unsigned long rate); struct of_device_id; typedef void (*of_clk_init_cb_t)(struct device_node *); int of_clk_add_provider(struct device_node *np, struct clk *(*clk_src_get)(struct of_phandle_args *args, void *data), void *data); void of_clk_del_provider(struct device_node *np); struct clk *of_clk_src_simple_get(struct of_phandle_args *clkspec, void *data); struct clk_onecell_data { struct clk **clks; unsigned int clk_num; }; struct clk *of_clk_src_onecell_get(struct of_phandle_args *clkspec, void *data); const char *of_clk_get_parent_name(struct device_node *np, int index); void of_clk_init(const struct of_device_id *matches); #define CLK_OF_DECLARE(name, compat, fn) \ static const struct of_device_id __clk_of_table_##name \ __used __section(__clk_of_table) \ = { .compatible = compat, .data = fn }; #endif /* CONFIG_COMMON_CLK */ #endif /* CLK_PROVIDER_H */