drivers/clk/ti/mux.c - linux - Git at Google

 /*
  * TI Multiplexer Clock
  *
  * Copyright (C) 2013 Texas Instruments, Inc.
  *
  * Tero Kristo <t-kristo@ti.com>
  *
  * 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.
  *
  * This program is distributed "as is" WITHOUT ANY WARRANTY of any
  * kind, whether express or implied; without even the implied warranty
  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  */

 #include <linux/clk-provider.h>
 #include <linux/slab.h>
 #include <linux/err.h>
 #include <linux/of.h>
 #include <linux/of_address.h>
 #include <linux/clk/ti.h>
 #include "clock.h"

 #undef pr_fmt
 #define pr_fmt(fmt) "%s: " fmt, __func__

 static u8 ti_clk_mux_get_parent(struct clk_hw *hw)
 {
 	struct clk_omap_mux *mux = to_clk_omap_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 = ti_clk_ll_ops->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 ti_clk_mux_set_parent(struct clk_hw *hw, u8 index)
 {
 	struct clk_omap_mux *mux = to_clk_omap_mux(hw);
 	u32 val;

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

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

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

 	return 0;
 }

 /**
  * clk_mux_save_context - Save the parent selcted in the mux
  * @hw: pointer  struct clk_hw
  *
  * Save the parent mux value.
  */
 static int clk_mux_save_context(struct clk_hw *hw)
 {
 	struct clk_omap_mux *mux = to_clk_omap_mux(hw);

 	mux->saved_parent = ti_clk_mux_get_parent(hw);
 	return 0;
 }

 /**
  * clk_mux_restore_context - Restore the parent in the mux
  * @hw: pointer  struct clk_hw
  *
  * Restore the saved parent mux value.
  */
 static void clk_mux_restore_context(struct clk_hw *hw)
 {
 	struct clk_omap_mux *mux = to_clk_omap_mux(hw);

 	ti_clk_mux_set_parent(hw, mux->saved_parent);
 }

 const struct clk_ops ti_clk_mux_ops = {
 	.get_parent = ti_clk_mux_get_parent,
 	.set_parent = ti_clk_mux_set_parent,
 	.determine_rate = __clk_mux_determine_rate,
 	.save_context = clk_mux_save_context,
 	.restore_context = clk_mux_restore_context,
 };

 static struct clk *_register_mux(struct device *dev, const char *name,
 				 const char * const *parent_names,
 				 u8 num_parents, unsigned long flags,
 				 struct clk_omap_reg *reg, u8 shift, u32 mask,
 				 s8 latch, u8 clk_mux_flags, u32 *table)
 {
 	struct clk_omap_mux *mux;
 	struct clk *clk;
 	struct clk_init_data init;

 	/* allocate the mux */
 	mux = kzalloc(sizeof(*mux), GFP_KERNEL);
 	if (!mux)
 		return ERR_PTR(-ENOMEM);

 	init.name = name;
 	init.ops = &ti_clk_mux_ops;
 	init.flags = flags;
 	init.parent_names = parent_names;
 	init.num_parents = num_parents;

 	/* struct clk_mux assignments */
 	memcpy(&mux->reg, reg, sizeof(*reg));
 	mux->shift = shift;
 	mux->mask = mask;
 	mux->latch = latch;
 	mux->flags = clk_mux_flags;
 	mux->table = table;
 	mux->hw.init = &init;

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

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

 	return clk;
 }

 struct clk *ti_clk_register_mux(struct ti_clk *setup)
 {
 	struct ti_clk_mux *mux;
 	u32 flags;
 	u8 mux_flags = 0;
 	struct clk_omap_reg reg;
 	u32 mask;

 	mux = setup->data;
 	flags = CLK_SET_RATE_NO_REPARENT;

 	mask = mux->num_parents;
 	if (!(mux->flags & CLKF_INDEX_STARTS_AT_ONE))
 		mask--;

 	mask = (1 << fls(mask)) - 1;
 	reg.index = mux->module;
 	reg.offset = mux->reg;
 	reg.ptr = NULL;

 	if (mux->flags & CLKF_INDEX_STARTS_AT_ONE)
 		mux_flags |= CLK_MUX_INDEX_ONE;

 	if (mux->flags & CLKF_SET_RATE_PARENT)
 		flags |= CLK_SET_RATE_PARENT;

 	return _register_mux(NULL, setup->name, mux->parents, mux->num_parents,
 			     flags, &reg, mux->bit_shift, mask, -EINVAL,
 			     mux_flags, NULL);
 }

 /**
  * of_mux_clk_setup - Setup function for simple mux rate clock
  * @node: DT node for the clock
  *
  * Sets up a basic clock multiplexer.
  */
 static void of_mux_clk_setup(struct device_node *node)
 {
 	struct clk *clk;
 	struct clk_omap_reg reg;
 	unsigned int num_parents;
 	const char **parent_names;
 	u8 clk_mux_flags = 0;
 	u32 mask = 0;
 	u32 shift = 0;
 	s32 latch = -EINVAL;
 	u32 flags = CLK_SET_RATE_NO_REPARENT;

 	num_parents = of_clk_get_parent_count(node);
 	if (num_parents < 2) {
 		pr_err("mux-clock %pOFn must have parents\n", node);
 		return;
 	}
 	parent_names = kzalloc((sizeof(char *) * num_parents), GFP_KERNEL);
 	if (!parent_names)
 		goto cleanup;

 	of_clk_parent_fill(node, parent_names, num_parents);

 	if (ti_clk_get_reg_addr(node, 0, &reg))
 		goto cleanup;

 	of_property_read_u32(node, "ti,bit-shift", &shift);

 	of_property_read_u32(node, "ti,latch-bit", &latch);

 	if (of_property_read_bool(node, "ti,index-starts-at-one"))
 		clk_mux_flags |= CLK_MUX_INDEX_ONE;

 	if (of_property_read_bool(node, "ti,set-rate-parent"))
 		flags |= CLK_SET_RATE_PARENT;

 	/* Generate bit-mask based on parent info */
 	mask = num_parents;
 	if (!(clk_mux_flags & CLK_MUX_INDEX_ONE))
 		mask--;

 	mask = (1 << fls(mask)) - 1;

 	clk = _register_mux(NULL, node->name, parent_names, num_parents,
 			    flags, &reg, shift, mask, latch, clk_mux_flags,
 			    NULL);

 	if (!IS_ERR(clk))
 		of_clk_add_provider(node, of_clk_src_simple_get, clk);

 cleanup:
 	kfree(parent_names);
 }
 CLK_OF_DECLARE(mux_clk, "ti,mux-clock", of_mux_clk_setup);

 struct clk_hw *ti_clk_build_component_mux(struct ti_clk_mux *setup)
 {
 	struct clk_omap_mux *mux;
 	int num_parents;

 	if (!setup)
 		return NULL;

 	mux = kzalloc(sizeof(*mux), GFP_KERNEL);
 	if (!mux)
 		return ERR_PTR(-ENOMEM);

 	mux->shift = setup->bit_shift;
 	mux->latch = -EINVAL;

 	mux->reg.index = setup->module;
 	mux->reg.offset = setup->reg;

 	if (setup->flags & CLKF_INDEX_STARTS_AT_ONE)
 		mux->flags |= CLK_MUX_INDEX_ONE;

 	num_parents = setup->num_parents;

 	mux->mask = num_parents - 1;
 	mux->mask = (1 << fls(mux->mask)) - 1;

 	return &mux->hw;
 }

 static void __init of_ti_composite_mux_clk_setup(struct device_node *node)
 {
 	struct clk_omap_mux *mux;
 	unsigned int num_parents;
 	u32 val;

 	mux = kzalloc(sizeof(*mux), GFP_KERNEL);
 	if (!mux)
 		return;

 	if (ti_clk_get_reg_addr(node, 0, &mux->reg))
 		goto cleanup;

 	if (!of_property_read_u32(node, "ti,bit-shift", &val))
 		mux->shift = val;

 	if (of_property_read_bool(node, "ti,index-starts-at-one"))
 		mux->flags |= CLK_MUX_INDEX_ONE;

 	num_parents = of_clk_get_parent_count(node);

 	if (num_parents < 2) {
 		pr_err("%pOFn must have parents\n", node);
 		goto cleanup;
 	}

 	mux->mask = num_parents - 1;
 	mux->mask = (1 << fls(mux->mask)) - 1;

 	if (!ti_clk_add_component(node, &mux->hw, CLK_COMPONENT_TYPE_MUX))
 		return;

 cleanup:
 	kfree(mux);
 }
 CLK_OF_DECLARE(ti_composite_mux_clk_setup, "ti,composite-mux-clock",
 	       of_ti_composite_mux_clk_setup);
	/*
	* TI Multiplexer Clock
	*
	* Copyright (C) 2013 Texas Instruments, Inc.
	*
	* Tero Kristo <t-kristo@ti.com>
	*
	* 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.
	*
	* This program is distributed "as is" WITHOUT ANY WARRANTY of any
	* kind, whether express or implied; without even the implied warranty
	* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*/

	#include <linux/clk-provider.h>
	#include <linux/slab.h>
	#include <linux/err.h>
	#include <linux/of.h>
	#include <linux/of_address.h>
	#include <linux/clk/ti.h>
	#include "clock.h"

	#undef pr_fmt
	#define pr_fmt(fmt) "%s: " fmt, __func__

	static u8 ti_clk_mux_get_parent(struct clk_hw *hw)
	{
	struct clk_omap_mux *mux = to_clk_omap_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 = ti_clk_ll_ops->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 ti_clk_mux_set_parent(struct clk_hw *hw, u8 index)
	{
	struct clk_omap_mux *mux = to_clk_omap_mux(hw);
	u32 val;

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

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

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

	return 0;
	}

	/**
	* clk_mux_save_context - Save the parent selcted in the mux
	* @hw: pointer struct clk_hw
	*
	* Save the parent mux value.
	*/
	static int clk_mux_save_context(struct clk_hw *hw)
	{
	struct clk_omap_mux *mux = to_clk_omap_mux(hw);

	mux->saved_parent = ti_clk_mux_get_parent(hw);
	return 0;
	}

	/**
	* clk_mux_restore_context - Restore the parent in the mux
	* @hw: pointer struct clk_hw
	*
	* Restore the saved parent mux value.
	*/
	static void clk_mux_restore_context(struct clk_hw *hw)
	{
	struct clk_omap_mux *mux = to_clk_omap_mux(hw);

	ti_clk_mux_set_parent(hw, mux->saved_parent);
	}

	const struct clk_ops ti_clk_mux_ops = {
	.get_parent = ti_clk_mux_get_parent,
	.set_parent = ti_clk_mux_set_parent,
	.determine_rate = __clk_mux_determine_rate,
	.save_context = clk_mux_save_context,
	.restore_context = clk_mux_restore_context,
	};

	static struct clk _register_mux(struct device dev, const char *name,
	const char * const *parent_names,
	u8 num_parents, unsigned long flags,
	struct clk_omap_reg *reg, u8 shift, u32 mask,
	s8 latch, u8 clk_mux_flags, u32 *table)
	{
	struct clk_omap_mux *mux;
	struct clk *clk;
	struct clk_init_data init;

	/* allocate the mux */
	mux = kzalloc(sizeof(*mux), GFP_KERNEL);
	if (!mux)
	return ERR_PTR(-ENOMEM);

	init.name = name;
	init.ops = &ti_clk_mux_ops;
	init.flags = flags;
	init.parent_names = parent_names;
	init.num_parents = num_parents;

	/* struct clk_mux assignments */
	memcpy(&mux->reg, reg, sizeof(*reg));
	mux->shift = shift;
	mux->mask = mask;
	mux->latch = latch;
	mux->flags = clk_mux_flags;
	mux->table = table;
	mux->hw.init = &init;

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

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

	return clk;
	}

	struct clk ti_clk_register_mux(struct ti_clk setup)
	{
	struct ti_clk_mux *mux;
	u32 flags;
	u8 mux_flags = 0;
	struct clk_omap_reg reg;
	u32 mask;

	mux = setup->data;
	flags = CLK_SET_RATE_NO_REPARENT;

	mask = mux->num_parents;
	if (!(mux->flags & CLKF_INDEX_STARTS_AT_ONE))
	mask--;

	mask = (1 << fls(mask)) - 1;
	reg.index = mux->module;
	reg.offset = mux->reg;
	reg.ptr = NULL;

	if (mux->flags & CLKF_INDEX_STARTS_AT_ONE)
	mux_flags \|= CLK_MUX_INDEX_ONE;

	if (mux->flags & CLKF_SET_RATE_PARENT)
	flags \|= CLK_SET_RATE_PARENT;

	return _register_mux(NULL, setup->name, mux->parents, mux->num_parents,
	flags, &reg, mux->bit_shift, mask, -EINVAL,
	mux_flags, NULL);
	}

	/**
	* of_mux_clk_setup - Setup function for simple mux rate clock
	* @node: DT node for the clock
	*
	* Sets up a basic clock multiplexer.
	*/
	static void of_mux_clk_setup(struct device_node *node)
	{
	struct clk *clk;
	struct clk_omap_reg reg;
	unsigned int num_parents;
	const char **parent_names;
	u8 clk_mux_flags = 0;
	u32 mask = 0;
	u32 shift = 0;
	s32 latch = -EINVAL;
	u32 flags = CLK_SET_RATE_NO_REPARENT;

	num_parents = of_clk_get_parent_count(node);
	if (num_parents < 2) {
	pr_err("mux-clock %pOFn must have parents\n", node);
	return;
	}
	parent_names = kzalloc((sizeof(char ) num_parents), GFP_KERNEL);
	if (!parent_names)
	goto cleanup;

	of_clk_parent_fill(node, parent_names, num_parents);

	if (ti_clk_get_reg_addr(node, 0, &reg))
	goto cleanup;

	of_property_read_u32(node, "ti,bit-shift", &shift);

	of_property_read_u32(node, "ti,latch-bit", &latch);

	if (of_property_read_bool(node, "ti,index-starts-at-one"))
	clk_mux_flags \|= CLK_MUX_INDEX_ONE;

	if (of_property_read_bool(node, "ti,set-rate-parent"))
	flags \|= CLK_SET_RATE_PARENT;

	/* Generate bit-mask based on parent info */
	mask = num_parents;
	if (!(clk_mux_flags & CLK_MUX_INDEX_ONE))
	mask--;

	mask = (1 << fls(mask)) - 1;

	clk = _register_mux(NULL, node->name, parent_names, num_parents,
	flags, &reg, shift, mask, latch, clk_mux_flags,
	NULL);

	if (!IS_ERR(clk))
	of_clk_add_provider(node, of_clk_src_simple_get, clk);

	cleanup:
	kfree(parent_names);
	}
	CLK_OF_DECLARE(mux_clk, "ti,mux-clock", of_mux_clk_setup);

	struct clk_hw ti_clk_build_component_mux(struct ti_clk_mux setup)
	{
	struct clk_omap_mux *mux;
	int num_parents;

	if (!setup)
	return NULL;

	mux = kzalloc(sizeof(*mux), GFP_KERNEL);
	if (!mux)
	return ERR_PTR(-ENOMEM);

	mux->shift = setup->bit_shift;
	mux->latch = -EINVAL;

	mux->reg.index = setup->module;
	mux->reg.offset = setup->reg;

	if (setup->flags & CLKF_INDEX_STARTS_AT_ONE)
	mux->flags \|= CLK_MUX_INDEX_ONE;

	num_parents = setup->num_parents;

	mux->mask = num_parents - 1;
	mux->mask = (1 << fls(mux->mask)) - 1;

	return &mux->hw;
	}

	static void __init of_ti_composite_mux_clk_setup(struct device_node *node)
	{
	struct clk_omap_mux *mux;
	unsigned int num_parents;
	u32 val;

	mux = kzalloc(sizeof(*mux), GFP_KERNEL);
	if (!mux)
	return;

	if (ti_clk_get_reg_addr(node, 0, &mux->reg))
	goto cleanup;

	if (!of_property_read_u32(node, "ti,bit-shift", &val))
	mux->shift = val;

	if (of_property_read_bool(node, "ti,index-starts-at-one"))
	mux->flags \|= CLK_MUX_INDEX_ONE;

	num_parents = of_clk_get_parent_count(node);

	if (num_parents < 2) {
	pr_err("%pOFn must have parents\n", node);
	goto cleanup;
	}

	mux->mask = num_parents - 1;
	mux->mask = (1 << fls(mux->mask)) - 1;

	if (!ti_clk_add_component(node, &mux->hw, CLK_COMPONENT_TYPE_MUX))
	return;

	cleanup:
	kfree(mux);
	}
	CLK_OF_DECLARE(ti_composite_mux_clk_setup, "ti,composite-mux-clock",
	of_ti_composite_mux_clk_setup);