[linux-2.6-block.git] / drivers / clk / clk-mux.c

/*
 * Copyright (C) 2011 Sascha Hauer, Pengutronix <s.hauer@pengutronix.de>
 * Copyright (C) 2011 Richard Zhao, Linaro <richard.zhao@linaro.org>
 * 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.
 *
 * Simple multiplexer clock implementation
 */

#include <linux/clk-provider.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/io.h>
#include <linux/err.h>

/*
 * DOC: basic adjustable multiplexer clock that cannot gate
 *
 * Traits of this clock:
 * prepare - clk_prepare only ensures that parents are prepared
 * enable - clk_enable only ensures that parents are enabled
 * rate - rate is only affected by parent switching.  No clk_set_rate support
 * parent - parent is adjustable through clk_set_parent
 */

static u8 clk_mux_get_parent(struct clk_hw *hw)
{
	struct clk_mux *mux = to_clk_mux(hw);
	int num_parents = clk_hw_get_num_parents(hw);
	u32 val;

	/*
	 * FIXME need a mux-specific flag to determine if val is bitwise or numeric
	 * e.g. sys_clkin_ck's clksel field is 3 bits wide, but ranges from 0x1
	 * to 0x7 (index starts at one)
	 * OTOH, pmd_trace_clk_mux_ck uses a separate bit for each clock, so
	 * val = 0x4 really means "bit 2, index starts at bit 0"
	 */
	val = clk_readl(mux->reg) >> mux->shift;
	val &= mux->mask;

	if (mux->table) {
		int i;

		for (i = 0; i < num_parents; i++)
			if (mux->table[i] == val)
				return i;
		return -EINVAL;
	}

	if (val && (mux->flags & CLK_MUX_INDEX_BIT))
		val = ffs(val) - 1;

	if (val && (mux->flags & CLK_MUX_INDEX_ONE))
		val--;

	if (val >= num_parents)
		return -EINVAL;

	return val;
}

static int clk_mux_set_parent(struct clk_hw *hw, u8 index)
{
	struct clk_mux *mux = to_clk_mux(hw);
	u32 val;
	unsigned long flags = 0;

	if (mux->table) {
		index = mux->table[index];
	} else {
		if (mux->flags & CLK_MUX_INDEX_BIT)
			index = 1 << index;

		if (mux->flags & CLK_MUX_INDEX_ONE)
			index++;
	}

	if (mux->lock)
		spin_lock_irqsave(mux->lock, flags);
	else
		__acquire(mux->lock);

	if (mux->flags & CLK_MUX_HIWORD_MASK) {
		val = mux->mask << (mux->shift + 16);
	} else {
		val = clk_readl(mux->reg);
		val &= ~(mux->mask << mux->shift);
	}
	val |= index << mux->shift;
	clk_writel(val, mux->reg);

	if (mux->lock)
		spin_unlock_irqrestore(mux->lock, flags);
	else
		__release(mux->lock);

	return 0;
}

const struct clk_ops clk_mux_ops = {
	.get_parent = clk_mux_get_parent,
	.set_parent = clk_mux_set_parent,
	.determine_rate = __clk_mux_determine_rate,
};
EXPORT_SYMBOL_GPL(clk_mux_ops);

const struct clk_ops clk_mux_ro_ops = {
	.get_parent = clk_mux_get_parent,
};
EXPORT_SYMBOL_GPL(clk_mux_ro_ops);

struct clk *clk_register_mux_table(struct device *dev, const char *name,
		const char * const *parent_names, u8 num_parents,
		unsigned long flags,
		void __iomem *reg, u8 shift, u32 mask,
		u8 clk_mux_flags, u32 *table, spinlock_t *lock)
{
	struct clk_mux *mux;
	struct clk *clk;
	struct clk_init_data init;
	u8 width = 0;

	if (clk_mux_flags & CLK_MUX_HIWORD_MASK) {
		width = fls(mask) - ffs(mask) + 1;
		if (width + shift > 16) {
			pr_err("mux value exceeds LOWORD field\n");
			return ERR_PTR(-EINVAL);
		}
	}

	/* allocate the mux */
	mux = kzalloc(sizeof(struct clk_mux), GFP_KERNEL);
	if (!mux) {
		pr_err("%s: could not allocate mux clk\n", __func__);
		return ERR_PTR(-ENOMEM);
	}

	init.name = name;
	if (clk_mux_flags & CLK_MUX_READ_ONLY)
		init.ops = &clk_mux_ro_ops;
	else
		init.ops = &clk_mux_ops;
	init.flags = flags | CLK_IS_BASIC;
	init.parent_names = parent_names;
	init.num_parents = num_parents;

	/* struct clk_mux assignments */
	mux->reg = reg;
	mux->shift = shift;
	mux->mask = mask;
	mux->flags = clk_mux_flags;
	mux->lock = lock;
	mux->table = table;
	mux->hw.init = &init;

	clk = clk_register(dev, &mux->hw);

	if (IS_ERR(clk))
		kfree(mux);

	return clk;
}
EXPORT_SYMBOL_GPL(clk_register_mux_table);

struct clk *clk_register_mux(struct device *dev, const char *name,
		const char * const *parent_names, u8 num_parents,
		unsigned long flags,
		void __iomem *reg, u8 shift, u8 width,
		u8 clk_mux_flags, spinlock_t *lock)
{
	u32 mask = BIT(width) - 1;

	return clk_register_mux_table(dev, name, parent_names, num_parents,
				      flags, reg, shift, mask, clk_mux_flags,
				      NULL, lock);
}
EXPORT_SYMBOL_GPL(clk_register_mux);

void clk_unregister_mux(struct clk *clk)
{
	struct clk_mux *mux;
	struct clk_hw *hw;

	hw = __clk_get_hw(clk);
	if (!hw)
		return;

	mux = to_clk_mux(hw);

	clk_unregister(clk);
	kfree(mux);
}
EXPORT_SYMBOL_GPL(clk_unregister_mux);
Commit	Line	Data
	1	/*
	2	* Copyright (C) 2011 Sascha Hauer, Pengutronix <s.hauer@pengutronix.de>
	3	* Copyright (C) 2011 Richard Zhao, Linaro <richard.zhao@linaro.org>
	4	* Copyright (C) 2011-2012 Mike Turquette, Linaro Ltd <mturquette@linaro.org>
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License version 2 as
	8	* published by the Free Software Foundation.
	9	*
	10	* Simple multiplexer clock implementation
	11	*/
	12
	13	#include <linux/clk-provider.h>
	14	#include <linux/module.h>
	15	#include <linux/slab.h>
	16	#include <linux/io.h>
	17	#include <linux/err.h>
	18
	19	/*
	20	* DOC: basic adjustable multiplexer clock that cannot gate
	21	*
	22	* Traits of this clock:
	23	* prepare - clk_prepare only ensures that parents are prepared
	24	* enable - clk_enable only ensures that parents are enabled
	25	* rate - rate is only affected by parent switching. No clk_set_rate support
	26	* parent - parent is adjustable through clk_set_parent
	27	*/
	28
	29	static u8 clk_mux_get_parent(struct clk_hw *hw)
	30	{
	31	struct clk_mux *mux = to_clk_mux(hw);
	32	int num_parents = clk_hw_get_num_parents(hw);
	33	u32 val;
	34
	35	/*
	36	* FIXME need a mux-specific flag to determine if val is bitwise or numeric
	37	* e.g. sys_clkin_ck's clksel field is 3 bits wide, but ranges from 0x1
	38	* to 0x7 (index starts at one)
	39	* OTOH, pmd_trace_clk_mux_ck uses a separate bit for each clock, so
	40	* val = 0x4 really means "bit 2, index starts at bit 0"
	41	*/
	42	val = clk_readl(mux->reg) >> mux->shift;
	43	val &= mux->mask;
	44
	45	if (mux->table) {
	46	int i;
	47
	48	for (i = 0; i < num_parents; i++)
	49	if (mux->table[i] == val)
	50	return i;
	51	return -EINVAL;
	52	}
	53
	54	if (val && (mux->flags & CLK_MUX_INDEX_BIT))
	55	val = ffs(val) - 1;
	56
	57	if (val && (mux->flags & CLK_MUX_INDEX_ONE))
	58	val--;
	59
	60	if (val >= num_parents)
	61	return -EINVAL;
	62
	63	return val;
	64	}
	65
	66	static int clk_mux_set_parent(struct clk_hw *hw, u8 index)
	67	{
	68	struct clk_mux *mux = to_clk_mux(hw);
	69	u32 val;
	70	unsigned long flags = 0;
	71
	72	if (mux->table) {
	73	index = mux->table[index];
	74	} else {
	75	if (mux->flags & CLK_MUX_INDEX_BIT)
	76	index = 1 << index;
	77
	78	if (mux->flags & CLK_MUX_INDEX_ONE)
	79	index++;
	80	}
	81
	82	if (mux->lock)
	83	spin_lock_irqsave(mux->lock, flags);
	84	else
	85	__acquire(mux->lock);
	86
	87	if (mux->flags & CLK_MUX_HIWORD_MASK) {
	88	val = mux->mask << (mux->shift + 16);
	89	} else {
	90	val = clk_readl(mux->reg);
	91	val &= ~(mux->mask << mux->shift);
	92	}
	93	val \|= index << mux->shift;
	94	clk_writel(val, mux->reg);
	95
	96	if (mux->lock)
	97	spin_unlock_irqrestore(mux->lock, flags);
	98	else
	99	__release(mux->lock);
	100
	101	return 0;
	102	}
	103
	104	const struct clk_ops clk_mux_ops = {
	105	.get_parent = clk_mux_get_parent,
	106	.set_parent = clk_mux_set_parent,
	107	.determine_rate = __clk_mux_determine_rate,
	108	};
	109	EXPORT_SYMBOL_GPL(clk_mux_ops);
	110
	111	const struct clk_ops clk_mux_ro_ops = {
	112	.get_parent = clk_mux_get_parent,
	113	};
	114	EXPORT_SYMBOL_GPL(clk_mux_ro_ops);
	115
	116	struct clk clk_register_mux_table(struct device dev, const char *name,
	117	const char * const *parent_names, u8 num_parents,
	118	unsigned long flags,
	119	void __iomem *reg, u8 shift, u32 mask,
	120	u8 clk_mux_flags, u32 table, spinlock_t lock)
	121	{
	122	struct clk_mux *mux;
	123	struct clk *clk;
	124	struct clk_init_data init;
	125	u8 width = 0;
	126
	127	if (clk_mux_flags & CLK_MUX_HIWORD_MASK) {
	128	width = fls(mask) - ffs(mask) + 1;
	129	if (width + shift > 16) {
	130	pr_err("mux value exceeds LOWORD field\n");
	131	return ERR_PTR(-EINVAL);
	132	}
	133	}
	134
	135	/* allocate the mux */
	136	mux = kzalloc(sizeof(struct clk_mux), GFP_KERNEL);
	137	if (!mux) {
	138	pr_err("%s: could not allocate mux clk\n", __func__);
	139	return ERR_PTR(-ENOMEM);
	140	}
	141
	142	init.name = name;
	143	if (clk_mux_flags & CLK_MUX_READ_ONLY)
	144	init.ops = &clk_mux_ro_ops;
	145	else
	146	init.ops = &clk_mux_ops;
	147	init.flags = flags \| CLK_IS_BASIC;
	148	init.parent_names = parent_names;
	149	init.num_parents = num_parents;
	150
	151	/* struct clk_mux assignments */
	152	mux->reg = reg;
	153	mux->shift = shift;
	154	mux->mask = mask;
	155	mux->flags = clk_mux_flags;
	156	mux->lock = lock;
	157	mux->table = table;
	158	mux->hw.init = &init;
	159
	160	clk = clk_register(dev, &mux->hw);
	161
	162	if (IS_ERR(clk))
	163	kfree(mux);
	164
	165	return clk;
	166	}
	167	EXPORT_SYMBOL_GPL(clk_register_mux_table);
	168
	169	struct clk clk_register_mux(struct device dev, const char *name,
	170	const char * const *parent_names, u8 num_parents,
	171	unsigned long flags,
	172	void __iomem *reg, u8 shift, u8 width,
	173	u8 clk_mux_flags, spinlock_t *lock)
	174	{
	175	u32 mask = BIT(width) - 1;
	176
	177	return clk_register_mux_table(dev, name, parent_names, num_parents,
	178	flags, reg, shift, mask, clk_mux_flags,
	179	NULL, lock);
	180	}
	181	EXPORT_SYMBOL_GPL(clk_register_mux);
	182
	183	void clk_unregister_mux(struct clk *clk)
	184	{
	185	struct clk_mux *mux;
	186	struct clk_hw *hw;
	187
	188	hw = __clk_get_hw(clk);
	189	if (!hw)
	190	return;
	191
	192	mux = to_clk_mux(hw);
	193
	194	clk_unregister(clk);
	195	kfree(mux);
	196	}
	197	EXPORT_SYMBOL_GPL(clk_unregister_mux);