arch/arm/mach-davinci/clock.c - kernel/prism - Git at Google

 /*
  * Clock and PLL control for DaVinci devices
  *
  * Copyright (C) 2006-2007 Texas Instruments.
  * Copyright (C) 2008-2009 Deep Root Systems, LLC
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
  * (at your option) any later version.
  */

 #include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/errno.h>
 #include <linux/clk.h>
 #include <linux/err.h>
 #include <linux/mutex.h>
 #include <linux/platform_device.h>
 #include <linux/io.h>

 #include <mach/hardware.h>

 #include <mach/psc.h>
 #include <mach/cputype.h>
 #include "clock.h"

 static LIST_HEAD(clocks);
 static DEFINE_MUTEX(clocks_mutex);
 static DEFINE_SPINLOCK(clockfw_lock);

 static unsigned psc_domain(struct clk *clk)
 {
 	return (clk->flags & PSC_DSP)
 		? DAVINCI_GPSC_DSPDOMAIN
 		: DAVINCI_GPSC_ARMDOMAIN;
 }

 static void __clk_enable(struct clk *clk)
 {
 	if (clk->parent)
 		__clk_enable(clk->parent);
 	if (clk->usecount++ == 0 && (clk->flags & CLK_PSC))
 		davinci_psc_config(psc_domain(clk), clk->psc_ctlr,
 				clk->lpsc, 1);
 }

 static void __clk_disable(struct clk *clk)
 {
 	if (WARN_ON(clk->usecount == 0))
 		return;
 	if (--clk->usecount == 0 && !(clk->flags & CLK_PLL))
 		davinci_psc_config(psc_domain(clk), clk->psc_ctlr,
 				clk->lpsc, 0);
 	if (clk->parent)
 		__clk_disable(clk->parent);
 }

 int clk_enable(struct clk *clk)
 {
 	unsigned long flags;

 	if (clk == NULL || IS_ERR(clk))
 		return -EINVAL;

 	spin_lock_irqsave(&clockfw_lock, flags);
 	__clk_enable(clk);
 	spin_unlock_irqrestore(&clockfw_lock, flags);

 	return 0;
 }
 EXPORT_SYMBOL(clk_enable);

 void clk_disable(struct clk *clk)
 {
 	unsigned long flags;

 	if (clk == NULL || IS_ERR(clk))
 		return;

 	spin_lock_irqsave(&clockfw_lock, flags);
 	__clk_disable(clk);
 	spin_unlock_irqrestore(&clockfw_lock, flags);
 }
 EXPORT_SYMBOL(clk_disable);

 unsigned long clk_get_rate(struct clk *clk)
 {
 	if (clk == NULL || IS_ERR(clk))
 		return -EINVAL;

 	return clk->rate;
 }
 EXPORT_SYMBOL(clk_get_rate);

 long clk_round_rate(struct clk *clk, unsigned long rate)
 {
 	if (clk == NULL || IS_ERR(clk))
 		return -EINVAL;

 	return clk->rate;
 }
 EXPORT_SYMBOL(clk_round_rate);

 int clk_set_rate(struct clk *clk, unsigned long rate)
 {
 	if (clk == NULL || IS_ERR(clk))
 		return -EINVAL;

 	/* changing the clk rate is not supported */
 	return -EINVAL;
 }
 EXPORT_SYMBOL(clk_set_rate);

 int clk_register(struct clk *clk)
 {
 	if (clk == NULL || IS_ERR(clk))
 		return -EINVAL;

 	if (WARN(clk->parent && !clk->parent->rate,
 			"CLK: %s parent %s has no rate!\n",
 			clk->name, clk->parent->name))
 		return -EINVAL;

 	mutex_lock(&clocks_mutex);
 	list_add_tail(&clk->node, &clocks);
 	mutex_unlock(&clocks_mutex);

 	/* If rate is already set, use it */
 	if (clk->rate)
 		return 0;

 	/* Otherwise, default to parent rate */
 	if (clk->parent)
 		clk->rate = clk->parent->rate;

 	return 0;
 }
 EXPORT_SYMBOL(clk_register);

 void clk_unregister(struct clk *clk)
 {
 	if (clk == NULL || IS_ERR(clk))
 		return;

 	mutex_lock(&clocks_mutex);
 	list_del(&clk->node);
 	mutex_unlock(&clocks_mutex);
 }
 EXPORT_SYMBOL(clk_unregister);

 #ifdef CONFIG_DAVINCI_RESET_CLOCKS
 /*
  * Disable any unused clocks left on by the bootloader
  */
 static int __init clk_disable_unused(void)
 {
 	struct clk *ck;

 	spin_lock_irq(&clockfw_lock);
 	list_for_each_entry(ck, &clocks, node) {
 		if (ck->usecount > 0)
 			continue;
 		if (!(ck->flags & CLK_PSC))
 			continue;

 		/* ignore if in Disabled or SwRstDisable states */
 		if (!davinci_psc_is_clk_active(ck->psc_ctlr, ck->lpsc))
 			continue;

 		pr_info("Clocks: disable unused %s\n", ck->name);
 		davinci_psc_config(psc_domain(ck), ck->psc_ctlr, ck->lpsc, 0);
 	}
 	spin_unlock_irq(&clockfw_lock);

 	return 0;
 }
 late_initcall(clk_disable_unused);
 #endif

 static void clk_sysclk_recalc(struct clk *clk)
 {
 	u32 v, plldiv;
 	struct pll_data *pll;

 	/* If this is the PLL base clock, no more calculations needed */
 	if (clk->pll_data)
 		return;

 	if (WARN_ON(!clk->parent))
 		return;

 	clk->rate = clk->parent->rate;

 	/* Otherwise, the parent must be a PLL */
 	if (WARN_ON(!clk->parent->pll_data))
 		return;

 	pll = clk->parent->pll_data;

 	/* If pre-PLL, source clock is before the multiplier and divider(s) */
 	if (clk->flags & PRE_PLL)
 		clk->rate = pll->input_rate;

 	if (!clk->div_reg)
 		return;

 	v = __raw_readl(pll->base + clk->div_reg);
 	if (v & PLLDIV_EN) {
 		plldiv = (v & PLLDIV_RATIO_MASK) + 1;
 		if (plldiv)
 			clk->rate /= plldiv;
 	}
 }

 static void __init clk_pll_init(struct clk *clk)
 {
 	u32 ctrl, mult = 1, prediv = 1, postdiv = 1;
 	u8 bypass;
 	struct pll_data *pll = clk->pll_data;

 	pll->base = IO_ADDRESS(pll->phys_base);
 	ctrl = __raw_readl(pll->base + PLLCTL);
 	clk->rate = pll->input_rate = clk->parent->rate;

 	if (ctrl & PLLCTL_PLLEN) {
 		bypass = 0;
 		mult = __raw_readl(pll->base + PLLM);
 		if (cpu_is_davinci_dm365())
 			mult = 2 * (mult & PLLM_PLLM_MASK);
 		else
 			mult = (mult & PLLM_PLLM_MASK) + 1;
 	} else
 		bypass = 1;

 	if (pll->flags & PLL_HAS_PREDIV) {
 		prediv = __raw_readl(pll->base + PREDIV);
 		if (prediv & PLLDIV_EN)
 			prediv = (prediv & PLLDIV_RATIO_MASK) + 1;
 		else
 			prediv = 1;
 	}

 	/* pre-divider is fixed, but (some?) chips won't report that */
 	if (cpu_is_davinci_dm355() && pll->num == 1)
 		prediv = 8;

 	if (pll->flags & PLL_HAS_POSTDIV) {
 		postdiv = __raw_readl(pll->base + POSTDIV);
 		if (postdiv & PLLDIV_EN)
 			postdiv = (postdiv & PLLDIV_RATIO_MASK) + 1;
 		else
 			postdiv = 1;
 	}

 	if (!bypass) {
 		clk->rate /= prediv;
 		clk->rate *= mult;
 		clk->rate /= postdiv;
 	}

 	pr_debug("PLL%d: input = %lu MHz [ ",
 		 pll->num, clk->parent->rate / 1000000);
 	if (bypass)
 		pr_debug("bypass ");
 	if (prediv > 1)
 		pr_debug("/ %d ", prediv);
 	if (mult > 1)
 		pr_debug("* %d ", mult);
 	if (postdiv > 1)
 		pr_debug("/ %d ", postdiv);
 	pr_debug("] --> %lu MHz output.\n", clk->rate / 1000000);
 }

 int __init davinci_clk_init(struct davinci_clk *clocks)
   {
 	struct davinci_clk *c;
 	struct clk *clk;

 	for (c = clocks; c->lk.clk; c++) {
 		clk = c->lk.clk;

 		if (clk->pll_data)
 			clk_pll_init(clk);

 		/* Calculate rates for PLL-derived clocks */
 		else if (clk->flags & CLK_PLL)
 			clk_sysclk_recalc(clk);

 		if (clk->lpsc)
 			clk->flags |= CLK_PSC;

 		clkdev_add(&c->lk);
 		clk_register(clk);

 		/* Turn on clocks that Linux doesn't otherwise manage */
 		if (clk->flags & ALWAYS_ENABLED)
 			clk_enable(clk);
 	}

 	return 0;
 }

 #ifdef CONFIG_PROC_FS
 #include <linux/proc_fs.h>
 #include <linux/seq_file.h>

 static void *davinci_ck_start(struct seq_file *m, loff_t *pos)
 {
 	return *pos < 1 ? (void *)1 : NULL;
 }

 static void *davinci_ck_next(struct seq_file *m, void *v, loff_t *pos)
 {
 	++*pos;
 	return NULL;
 }

 static void davinci_ck_stop(struct seq_file *m, void *v)
 {
 }

 #define CLKNAME_MAX	10		/* longest clock name */
 #define NEST_DELTA	2
 #define NEST_MAX	4

 static void
 dump_clock(struct seq_file *s, unsigned nest, struct clk *parent)
 {
 	char		*state;
 	char		buf[CLKNAME_MAX + NEST_DELTA * NEST_MAX];
 	struct clk	*clk;
 	unsigned	i;

 	if (parent->flags & CLK_PLL)
 		state = "pll";
 	else if (parent->flags & CLK_PSC)
 		state = "psc";
 	else
 		state = "";

 	/* <nest spaces> name <pad to end> */
 	memset(buf, ' ', sizeof(buf) - 1);
 	buf[sizeof(buf) - 1] = 0;
 	i = strlen(parent->name);
 	memcpy(buf + nest, parent->name,
 			min(i, (unsigned)(sizeof(buf) - 1 - nest)));

 	seq_printf(s, "%s users=%2d %-3s %9ld Hz\n",
 		   buf, parent->usecount, state, clk_get_rate(parent));
 	/* REVISIT show device associations too */

 	/* cost is now small, but not linear... */
 	list_for_each_entry(clk, &clocks, node) {
 		if (clk->parent == parent)
 			dump_clock(s, nest + NEST_DELTA, clk);
 	}
 }

 static int davinci_ck_show(struct seq_file *m, void *v)
 {
 	/* Show clock tree; we know the main oscillator is first.
 	 * We trust nonzero usecounts equate to PSC enables...
 	 */
 	mutex_lock(&clocks_mutex);
 	if (!list_empty(&clocks))
 		dump_clock(m, 0, list_first_entry(&clocks, struct clk, node));
 	mutex_unlock(&clocks_mutex);

 	return 0;
 }

 static const struct seq_operations davinci_ck_op = {
 	.start	= davinci_ck_start,
 	.next	= davinci_ck_next,
 	.stop	= davinci_ck_stop,
 	.show	= davinci_ck_show
 };

 static int davinci_ck_open(struct inode *inode, struct file *file)
 {
 	return seq_open(file, &davinci_ck_op);
 }

 static const struct file_operations proc_davinci_ck_operations = {
 	.open		= davinci_ck_open,
 	.read		= seq_read,
 	.llseek		= seq_lseek,
 	.release	= seq_release,
 };

 static int __init davinci_ck_proc_init(void)
 {
 	proc_create("davinci_clocks", 0, NULL, &proc_davinci_ck_operations);
 	return 0;

 }
 __initcall(davinci_ck_proc_init);
 #endif /* CONFIG_DEBUG_PROC_FS */
	/*
	* Clock and PLL control for DaVinci devices
	*
	* Copyright (C) 2006-2007 Texas Instruments.
	* Copyright (C) 2008-2009 Deep Root Systems, LLC
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; either version 2 of the License, or
	* (at your option) any later version.
	*/

	#include <linux/module.h>
	#include <linux/kernel.h>
	#include <linux/init.h>
	#include <linux/errno.h>
	#include <linux/clk.h>
	#include <linux/err.h>
	#include <linux/mutex.h>
	#include <linux/platform_device.h>
	#include <linux/io.h>

	#include <mach/hardware.h>

	#include <mach/psc.h>
	#include <mach/cputype.h>
	#include "clock.h"

	static LIST_HEAD(clocks);
	static DEFINE_MUTEX(clocks_mutex);
	static DEFINE_SPINLOCK(clockfw_lock);

	static unsigned psc_domain(struct clk *clk)
	{
	return (clk->flags & PSC_DSP)
	? DAVINCI_GPSC_DSPDOMAIN
	: DAVINCI_GPSC_ARMDOMAIN;
	}

	static void __clk_enable(struct clk *clk)
	{
	if (clk->parent)
	__clk_enable(clk->parent);
	if (clk->usecount++ == 0 && (clk->flags & CLK_PSC))
	davinci_psc_config(psc_domain(clk), clk->psc_ctlr,
	clk->lpsc, 1);
	}

	static void __clk_disable(struct clk *clk)
	{
	if (WARN_ON(clk->usecount == 0))
	return;
	if (--clk->usecount == 0 && !(clk->flags & CLK_PLL))
	davinci_psc_config(psc_domain(clk), clk->psc_ctlr,
	clk->lpsc, 0);
	if (clk->parent)
	__clk_disable(clk->parent);
	}

	int clk_enable(struct clk *clk)
	{
	unsigned long flags;

	if (clk == NULL \|\| IS_ERR(clk))
	return -EINVAL;

	spin_lock_irqsave(&clockfw_lock, flags);
	__clk_enable(clk);
	spin_unlock_irqrestore(&clockfw_lock, flags);

	return 0;
	}
	EXPORT_SYMBOL(clk_enable);

	void clk_disable(struct clk *clk)
	{
	unsigned long flags;

	if (clk == NULL \|\| IS_ERR(clk))
	return;

	spin_lock_irqsave(&clockfw_lock, flags);
	__clk_disable(clk);
	spin_unlock_irqrestore(&clockfw_lock, flags);
	}
	EXPORT_SYMBOL(clk_disable);

	unsigned long clk_get_rate(struct clk *clk)
	{
	if (clk == NULL \|\| IS_ERR(clk))
	return -EINVAL;

	return clk->rate;
	}
	EXPORT_SYMBOL(clk_get_rate);

	long clk_round_rate(struct clk *clk, unsigned long rate)
	{
	if (clk == NULL \|\| IS_ERR(clk))
	return -EINVAL;

	return clk->rate;
	}
	EXPORT_SYMBOL(clk_round_rate);

	int clk_set_rate(struct clk *clk, unsigned long rate)
	{
	if (clk == NULL \|\| IS_ERR(clk))
	return -EINVAL;

	/* changing the clk rate is not supported */
	return -EINVAL;
	}
	EXPORT_SYMBOL(clk_set_rate);

	int clk_register(struct clk *clk)
	{
	if (clk == NULL \|\| IS_ERR(clk))
	return -EINVAL;

	if (WARN(clk->parent && !clk->parent->rate,
	"CLK: %s parent %s has no rate!\n",
	clk->name, clk->parent->name))
	return -EINVAL;

	mutex_lock(&clocks_mutex);
	list_add_tail(&clk->node, &clocks);
	mutex_unlock(&clocks_mutex);

	/* If rate is already set, use it */
	if (clk->rate)
	return 0;

	/* Otherwise, default to parent rate */
	if (clk->parent)
	clk->rate = clk->parent->rate;

	return 0;
	}
	EXPORT_SYMBOL(clk_register);

	void clk_unregister(struct clk *clk)
	{
	if (clk == NULL \|\| IS_ERR(clk))
	return;

	mutex_lock(&clocks_mutex);
	list_del(&clk->node);
	mutex_unlock(&clocks_mutex);
	}
	EXPORT_SYMBOL(clk_unregister);

	#ifdef CONFIG_DAVINCI_RESET_CLOCKS
	/*
	* Disable any unused clocks left on by the bootloader
	*/
	static int __init clk_disable_unused(void)
	{
	struct clk *ck;

	spin_lock_irq(&clockfw_lock);
	list_for_each_entry(ck, &clocks, node) {
	if (ck->usecount > 0)
	continue;
	if (!(ck->flags & CLK_PSC))
	continue;

	/* ignore if in Disabled or SwRstDisable states */
	if (!davinci_psc_is_clk_active(ck->psc_ctlr, ck->lpsc))
	continue;

	pr_info("Clocks: disable unused %s\n", ck->name);
	davinci_psc_config(psc_domain(ck), ck->psc_ctlr, ck->lpsc, 0);
	}
	spin_unlock_irq(&clockfw_lock);

	return 0;
	}
	late_initcall(clk_disable_unused);
	#endif

	static void clk_sysclk_recalc(struct clk *clk)
	{
	u32 v, plldiv;
	struct pll_data *pll;

	/* If this is the PLL base clock, no more calculations needed */
	if (clk->pll_data)
	return;

	if (WARN_ON(!clk->parent))
	return;

	clk->rate = clk->parent->rate;

	/* Otherwise, the parent must be a PLL */
	if (WARN_ON(!clk->parent->pll_data))
	return;

	pll = clk->parent->pll_data;

	/* If pre-PLL, source clock is before the multiplier and divider(s) */
	if (clk->flags & PRE_PLL)
	clk->rate = pll->input_rate;

	if (!clk->div_reg)
	return;

	v = __raw_readl(pll->base + clk->div_reg);
	if (v & PLLDIV_EN) {
	plldiv = (v & PLLDIV_RATIO_MASK) + 1;
	if (plldiv)
	clk->rate /= plldiv;
	}
	}

	static void __init clk_pll_init(struct clk *clk)
	{
	u32 ctrl, mult = 1, prediv = 1, postdiv = 1;
	u8 bypass;
	struct pll_data *pll = clk->pll_data;

	pll->base = IO_ADDRESS(pll->phys_base);
	ctrl = __raw_readl(pll->base + PLLCTL);
	clk->rate = pll->input_rate = clk->parent->rate;

	if (ctrl & PLLCTL_PLLEN) {
	bypass = 0;
	mult = __raw_readl(pll->base + PLLM);
	if (cpu_is_davinci_dm365())
	mult = 2 * (mult & PLLM_PLLM_MASK);
	else
	mult = (mult & PLLM_PLLM_MASK) + 1;
	} else
	bypass = 1;

	if (pll->flags & PLL_HAS_PREDIV) {
	prediv = __raw_readl(pll->base + PREDIV);
	if (prediv & PLLDIV_EN)
	prediv = (prediv & PLLDIV_RATIO_MASK) + 1;
	else
	prediv = 1;
	}

	/* pre-divider is fixed, but (some?) chips won't report that */
	if (cpu_is_davinci_dm355() && pll->num == 1)
	prediv = 8;

	if (pll->flags & PLL_HAS_POSTDIV) {
	postdiv = __raw_readl(pll->base + POSTDIV);
	if (postdiv & PLLDIV_EN)
	postdiv = (postdiv & PLLDIV_RATIO_MASK) + 1;
	else
	postdiv = 1;
	}

	if (!bypass) {
	clk->rate /= prediv;
	clk->rate *= mult;
	clk->rate /= postdiv;
	}

	pr_debug("PLL%d: input = %lu MHz [ ",
	pll->num, clk->parent->rate / 1000000);
	if (bypass)
	pr_debug("bypass ");
	if (prediv > 1)
	pr_debug("/ %d ", prediv);
	if (mult > 1)
	pr_debug("* %d ", mult);
	if (postdiv > 1)
	pr_debug("/ %d ", postdiv);
	pr_debug("] --> %lu MHz output.\n", clk->rate / 1000000);
	}

	int __init davinci_clk_init(struct davinci_clk *clocks)
	{
	struct davinci_clk *c;
	struct clk *clk;

	for (c = clocks; c->lk.clk; c++) {
	clk = c->lk.clk;

	if (clk->pll_data)
	clk_pll_init(clk);

	/* Calculate rates for PLL-derived clocks */
	else if (clk->flags & CLK_PLL)
	clk_sysclk_recalc(clk);

	if (clk->lpsc)
	clk->flags \|= CLK_PSC;

	clkdev_add(&c->lk);
	clk_register(clk);

	/* Turn on clocks that Linux doesn't otherwise manage */
	if (clk->flags & ALWAYS_ENABLED)
	clk_enable(clk);
	}

	return 0;
	}

	#ifdef CONFIG_PROC_FS
	#include <linux/proc_fs.h>
	#include <linux/seq_file.h>

	static void davinci_ck_start(struct seq_file m, loff_t *pos)
	{
	return pos < 1 ? (void )1 : NULL;
	}

	static void davinci_ck_next(struct seq_file m, void v, loff_t pos)
	{
	++*pos;
	return NULL;
	}

	static void davinci_ck_stop(struct seq_file m, void v)
	{
	}

	#define CLKNAME_MAX 10 /* longest clock name */
	#define NEST_DELTA 2
	#define NEST_MAX 4

	static void
	dump_clock(struct seq_file s, unsigned nest, struct clk parent)
	{
	char *state;
	char buf[CLKNAME_MAX + NEST_DELTA * NEST_MAX];
	struct clk *clk;
	unsigned i;

	if (parent->flags & CLK_PLL)
	state = "pll";
	else if (parent->flags & CLK_PSC)
	state = "psc";
	else
	state = "";

	/* <nest spaces> name <pad to end> */
	memset(buf, ' ', sizeof(buf) - 1);
	buf[sizeof(buf) - 1] = 0;
	i = strlen(parent->name);
	memcpy(buf + nest, parent->name,
	min(i, (unsigned)(sizeof(buf) - 1 - nest)));

	seq_printf(s, "%s users=%2d %-3s %9ld Hz\n",
	buf, parent->usecount, state, clk_get_rate(parent));
	/* REVISIT show device associations too */

	/* cost is now small, but not linear... */
	list_for_each_entry(clk, &clocks, node) {
	if (clk->parent == parent)
	dump_clock(s, nest + NEST_DELTA, clk);
	}
	}

	static int davinci_ck_show(struct seq_file m, void v)
	{
	/* Show clock tree; we know the main oscillator is first.
	* We trust nonzero usecounts equate to PSC enables...
	*/
	mutex_lock(&clocks_mutex);
	if (!list_empty(&clocks))
	dump_clock(m, 0, list_first_entry(&clocks, struct clk, node));
	mutex_unlock(&clocks_mutex);

	return 0;
	}

	static const struct seq_operations davinci_ck_op = {
	.start = davinci_ck_start,
	.next = davinci_ck_next,
	.stop = davinci_ck_stop,
	.show = davinci_ck_show
	};

	static int davinci_ck_open(struct inode inode, struct file file)
	{
	return seq_open(file, &davinci_ck_op);
	}

	static const struct file_operations proc_davinci_ck_operations = {
	.open = davinci_ck_open,
	.read = seq_read,
	.llseek = seq_lseek,
	.release = seq_release,
	};

	static int __init davinci_ck_proc_init(void)
	{
	proc_create("davinci_clocks", 0, NULL, &proc_davinci_ck_operations);
	return 0;

	}
	__initcall(davinci_ck_proc_init);
	#endif /* CONFIG_DEBUG_PROC_FS */