/* Copyright (c) 2009-2012, The Linux Foundation. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 and
 * only version 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 */

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

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/err.h>
#include <linux/ctype.h>
#include <linux/bitops.h>
#include <linux/io.h>
#include <linux/spinlock.h>
#include <linux/delay.h>
#include <linux/clk.h>

#include <mach/msm_iomap.h>
#include <mach/clk-provider.h>
#include <mach/clk.h>
#include <mach/scm-io.h>

#include "clock-local.h"


/*
 * When enabling/disabling a clock, check the halt bit up to this number
 * number of times (with a 1 us delay in between) before continuing.
 */
#define HALT_CHECK_MAX_LOOPS	200
/* For clock without halt checking, wait this long after enables/disables. */
#define HALT_CHECK_DELAY_US	10

DEFINE_SPINLOCK(local_clock_reg_lock);
struct clk_freq_tbl rcg_dummy_freq = F_END;

/*
 * Common Set-Rate Functions
 */

/* For clocks with MND dividers. */
void set_rate_mnd(struct rcg_clk *rcg, struct clk_freq_tbl *nf)
{
	uint32_t ns_reg_val, ctl_reg_val;

	/* Assert MND reset. */
	ns_reg_val = readl_relaxed(rcg->ns_reg);
	ns_reg_val |= BIT(7);
	writel_relaxed(ns_reg_val, rcg->ns_reg);

	/* Program M and D values. */
	writel_relaxed(nf->md_val, rcg->md_reg);

	/* If the clock has a separate CC register, program it. */
	if (rcg->ns_reg != rcg->b.ctl_reg) {
		ctl_reg_val = readl_relaxed(rcg->b.ctl_reg);
		ctl_reg_val &= ~(rcg->ctl_mask);
		ctl_reg_val |= nf->ctl_val;
		writel_relaxed(ctl_reg_val, rcg->b.ctl_reg);
	}

	/* Deassert MND reset. */
	ns_reg_val &= ~BIT(7);
	writel_relaxed(ns_reg_val, rcg->ns_reg);
}

void set_rate_nop(struct rcg_clk *rcg, struct clk_freq_tbl *nf)
{
	/*
	 * Nothing to do for fixed-rate or integer-divider clocks. Any settings
	 * in NS registers are applied in the enable path, since power can be
	 * saved by leaving an un-clocked or slowly-clocked source selected
	 * until the clock is enabled.
	 */
}

void set_rate_mnd_8(struct rcg_clk *rcg, struct clk_freq_tbl *nf)
{
	uint32_t ctl_reg_val;

	/* Assert MND reset. */
	ctl_reg_val = readl_relaxed(rcg->b.ctl_reg);
	ctl_reg_val |= BIT(8);
	writel_relaxed(ctl_reg_val, rcg->b.ctl_reg);

	/* Program M and D values. */
	writel_relaxed(nf->md_val, rcg->md_reg);

	/* Program MN counter Enable and Mode. */
	ctl_reg_val &= ~(rcg->ctl_mask);
	ctl_reg_val |= nf->ctl_val;
	writel_relaxed(ctl_reg_val, rcg->b.ctl_reg);

	/* Deassert MND reset. */
	ctl_reg_val &= ~BIT(8);
	writel_relaxed(ctl_reg_val, rcg->b.ctl_reg);
}

void set_rate_mnd_banked(struct rcg_clk *rcg, struct clk_freq_tbl *nf)
{
	struct bank_masks *banks = rcg->bank_info;
	const struct bank_mask_info *new_bank_masks;
	const struct bank_mask_info *old_bank_masks;
	uint32_t ns_reg_val, ctl_reg_val;
	uint32_t bank_sel;

	/*
	 * Determine active bank and program the other one. If the clock is
	 * off, program the active bank since bank switching won't work if
	 * both banks aren't running.
	 */
	ctl_reg_val = readl_relaxed(rcg->b.ctl_reg);
	bank_sel = !!(ctl_reg_val & banks->bank_sel_mask);
	 /* If clock isn't running, don't switch banks. */
	bank_sel ^= (!rcg->enabled || rcg->current_freq->freq_hz == 0);
	if (bank_sel == 0) {
		new_bank_masks = &banks->bank1_mask;
		old_bank_masks = &banks->bank0_mask;
	} else {
		new_bank_masks = &banks->bank0_mask;
		old_bank_masks = &banks->bank1_mask;
	}

	ns_reg_val = readl_relaxed(rcg->ns_reg);

	/* Assert bank MND reset. */
	ns_reg_val |= new_bank_masks->rst_mask;
	writel_relaxed(ns_reg_val, rcg->ns_reg);

	/*
	 * Program NS only if the clock is enabled, since the NS will be set
	 * as part of the enable procedure and should remain with a low-power
	 * MUX input selected until then.
	 */
	if (rcg->enabled) {
		ns_reg_val &= ~(new_bank_masks->ns_mask);
		ns_reg_val |= (nf->ns_val & new_bank_masks->ns_mask);
		writel_relaxed(ns_reg_val, rcg->ns_reg);
	}

	writel_relaxed(nf->md_val, new_bank_masks->md_reg);

	/* Enable counter only if clock is enabled. */
	if (rcg->enabled)
		ctl_reg_val |= new_bank_masks->mnd_en_mask;
	else
		ctl_reg_val &= ~(new_bank_masks->mnd_en_mask);

	ctl_reg_val &= ~(new_bank_masks->mode_mask);
	ctl_reg_val |= (nf->ctl_val & new_bank_masks->mode_mask);
	writel_relaxed(ctl_reg_val, rcg->b.ctl_reg);

	/* Deassert bank MND reset. */
	ns_reg_val &= ~(new_bank_masks->rst_mask);
	writel_relaxed(ns_reg_val, rcg->ns_reg);

	/*
	 * Switch to the new bank if clock is running.  If it isn't, then
	 * no switch is necessary since we programmed the active bank.
	 */
	if (rcg->enabled && rcg->current_freq->freq_hz) {
		ctl_reg_val ^= banks->bank_sel_mask;
		writel_relaxed(ctl_reg_val, rcg->b.ctl_reg);
		/*
		 * Wait at least 6 cycles of slowest bank's clock
		 * for the glitch-free MUX to fully switch sources.
		 */
		mb();
		udelay(1);

		/* Disable old bank's MN counter. */
		ctl_reg_val &= ~(old_bank_masks->mnd_en_mask);
		writel_relaxed(ctl_reg_val, rcg->b.ctl_reg);

		/* Program old bank to a low-power source and divider. */
		ns_reg_val &= ~(old_bank_masks->ns_mask);
		ns_reg_val |= (rcg->freq_tbl->ns_val & old_bank_masks->ns_mask);
		writel_relaxed(ns_reg_val, rcg->ns_reg);
	}

	/* Update the MND_EN and NS masks to match the current bank. */
	rcg->mnd_en_mask = new_bank_masks->mnd_en_mask;
	rcg->ns_mask = new_bank_masks->ns_mask;
}

void set_rate_div_banked(struct rcg_clk *rcg, struct clk_freq_tbl *nf)
{
	struct bank_masks *banks = rcg->bank_info;
	const struct bank_mask_info *new_bank_masks;
	const struct bank_mask_info *old_bank_masks;
	uint32_t ns_reg_val, bank_sel;

	/*
	 * Determine active bank and program the other one. If the clock is
	 * off, program the active bank since bank switching won't work if
	 * both banks aren't running.
	 */
	ns_reg_val = readl_relaxed(rcg->ns_reg);
	bank_sel = !!(ns_reg_val & banks->bank_sel_mask);
	 /* If clock isn't running, don't switch banks. */
	bank_sel ^= (!rcg->enabled || rcg->current_freq->freq_hz == 0);
	if (bank_sel == 0) {
		new_bank_masks = &banks->bank1_mask;
		old_bank_masks = &banks->bank0_mask;
	} else {
		new_bank_masks = &banks->bank0_mask;
		old_bank_masks = &banks->bank1_mask;
	}

	/*
	 * Program NS only if the clock is enabled, since the NS will be set
	 * as part of the enable procedure and should remain with a low-power
	 * MUX input selected until then.
	 */
	if (rcg->enabled) {
		ns_reg_val &= ~(new_bank_masks->ns_mask);
		ns_reg_val |= (nf->ns_val & new_bank_masks->ns_mask);
		writel_relaxed(ns_reg_val, rcg->ns_reg);
	}

	/*
	 * Switch to the new bank if clock is running.  If it isn't, then
	 * no switch is necessary since we programmed the active bank.
	 */
	if (rcg->enabled && rcg->current_freq->freq_hz) {
		ns_reg_val ^= banks->bank_sel_mask;
		writel_relaxed(ns_reg_val, rcg->ns_reg);
		/*
		 * Wait at least 6 cycles of slowest bank's clock
		 * for the glitch-free MUX to fully switch sources.
		 */
		mb();
		udelay(1);

		/* Program old bank to a low-power source and divider. */
		ns_reg_val &= ~(old_bank_masks->ns_mask);
		ns_reg_val |= (rcg->freq_tbl->ns_val & old_bank_masks->ns_mask);
		writel_relaxed(ns_reg_val, rcg->ns_reg);
	}

	/* Update the NS mask to match the current bank. */
	rcg->ns_mask = new_bank_masks->ns_mask;
}

/*
 * Clock enable/disable functions
 */

/* Return non-zero if a clock status registers shows the clock is halted. */
static int branch_clk_is_halted(const struct branch *b)
{
	int invert = (b->halt_check == ENABLE);
	int status_bit = readl_relaxed(b->halt_reg) & BIT(b->halt_bit);
	return invert ? !status_bit : status_bit;
}

static int branch_in_hwcg_mode(const struct branch *b)
{
	if (!b->hwcg_mask)
		return 0;

	return !!(readl_relaxed(b->hwcg_reg) & b->hwcg_mask);
}

void __branch_enable_reg(const struct branch *b, const char *name)
{
	u32 reg_val;

	if (b->en_mask) {
		reg_val = readl_relaxed(b->ctl_reg);
		reg_val |= b->en_mask;
		writel_relaxed(reg_val, b->ctl_reg);
	}

	/*
	 * Use a memory barrier since some halt status registers are
	 * not within the same 1K segment as the branch/root enable
	 * registers.  It's also needed in the udelay() case to ensure
	 * the delay starts after the branch enable.
	 */
	mb();

	/* Skip checking halt bit if the clock is in hardware gated mode */
	if (branch_in_hwcg_mode(b))
		return;

	/* Wait for clock to enable before returning. */
	if (b->halt_check == DELAY) {
		udelay(HALT_CHECK_DELAY_US);
	} else if (b->halt_check == ENABLE || b->halt_check == HALT
			|| b->halt_check == ENABLE_VOTED
			|| b->halt_check == HALT_VOTED) {
		int count;

		/* Wait up to HALT_CHECK_MAX_LOOPS for clock to enable. */
		for (count = HALT_CHECK_MAX_LOOPS; branch_clk_is_halted(b)
					&& count > 0; count--)
			udelay(1);
		WARN(count == 0, "%s status stuck at 'off'", name);
	}
}

/* Perform any register operations required to enable the clock. */
static void __rcg_clk_enable_reg(struct rcg_clk *rcg)
{
	u32 reg_val;
	void __iomem *const reg = rcg->b.ctl_reg;

	/*
	 * Program the NS register, if applicable. NS registers are not
	 * set in the set_rate path because power can be saved by deferring
	 * the selection of a clocked source until the clock is enabled.
	 */
	if (rcg->ns_mask) {
		reg_val = readl_relaxed(rcg->ns_reg);
		reg_val &= ~(rcg->ns_mask);
		reg_val |= (rcg->current_freq->ns_val & rcg->ns_mask);
		writel_relaxed(reg_val, rcg->ns_reg);
	}

	/* Enable MN counter, if applicable. */
	reg_val = readl_relaxed(reg);
	if (rcg->current_freq->md_val) {
		reg_val |= rcg->mnd_en_mask;
		writel_relaxed(reg_val, reg);
	}
	/* Enable root. */
	if (rcg->root_en_mask) {
		reg_val |= rcg->root_en_mask;
		writel_relaxed(reg_val, reg);
	}
	__branch_enable_reg(&rcg->b, rcg->c.dbg_name);
}

/* Perform any register operations required to disable the branch. */
u32 __branch_disable_reg(const struct branch *b, const char *name)
{
	u32 reg_val;

	reg_val = b->ctl_reg ? readl_relaxed(b->ctl_reg) : 0;
	if (b->en_mask) {
		reg_val &= ~(b->en_mask);
		writel_relaxed(reg_val, b->ctl_reg);
	}

	/*
	 * Use a memory barrier since some halt status registers are
	 * not within the same K segment as the branch/root enable
	 * registers.  It's also needed in the udelay() case to ensure
	 * the delay starts after the branch disable.
	 */
	mb();

	/* Skip checking halt bit if the clock is in hardware gated mode */
	if (branch_in_hwcg_mode(b))
		return reg_val;

	/* Wait for clock to disable before continuing. */
	if (b->halt_check == DELAY || b->halt_check == ENABLE_VOTED
				   || b->halt_check == HALT_VOTED) {
		udelay(HALT_CHECK_DELAY_US);
	} else if (b->halt_check == ENABLE || b->halt_check == HALT) {
		int count;

		/* Wait up to HALT_CHECK_MAX_LOOPS for clock to disable. */
		for (count = HALT_CHECK_MAX_LOOPS; !branch_clk_is_halted(b)
					&& count > 0; count--)
			udelay(1);
		WARN(count == 0, "%s status stuck at 'on'", name);
	}

	return reg_val;
}

/* Perform any register operations required to disable the generator. */
static void __rcg_clk_disable_reg(struct rcg_clk *rcg)
{
	void __iomem *const reg = rcg->b.ctl_reg;
	uint32_t reg_val;

	reg_val = __branch_disable_reg(&rcg->b, rcg->c.dbg_name);
	/* Disable root. */
	if (rcg->root_en_mask) {
		reg_val &= ~(rcg->root_en_mask);
		writel_relaxed(reg_val, reg);
	}
	/* Disable MN counter, if applicable. */
	if (rcg->current_freq->md_val) {
		reg_val &= ~(rcg->mnd_en_mask);
		writel_relaxed(reg_val, reg);
	}
	/*
	 * Program NS register to low-power value with an un-clocked or
	 * slowly-clocked source selected.
	 */
	if (rcg->ns_mask) {
		reg_val = readl_relaxed(rcg->ns_reg);
		reg_val &= ~(rcg->ns_mask);
		reg_val |= (rcg->freq_tbl->ns_val & rcg->ns_mask);
		writel_relaxed(reg_val, rcg->ns_reg);
	}
}

static int rcg_clk_prepare(struct clk *c)
{
	struct rcg_clk *rcg = to_rcg_clk(c);

	WARN(rcg->current_freq == &rcg_dummy_freq,
		"Attempting to prepare %s before setting its rate. "
		"Set the rate first!\n", rcg->c.dbg_name);
	rcg->prepared = true;

	return 0;
}

/* Enable a rate-settable clock. */
static int rcg_clk_enable(struct clk *c)
{
	unsigned long flags;
	struct rcg_clk *rcg = to_rcg_clk(c);

	spin_lock_irqsave(&local_clock_reg_lock, flags);
	__rcg_clk_enable_reg(rcg);
	rcg->enabled = true;
	spin_unlock_irqrestore(&local_clock_reg_lock, flags);

	return 0;
}

/* Disable a rate-settable clock. */
static void rcg_clk_disable(struct clk *c)
{
	unsigned long flags;
	struct rcg_clk *rcg = to_rcg_clk(c);

	spin_lock_irqsave(&local_clock_reg_lock, flags);
	__rcg_clk_disable_reg(rcg);
	rcg->enabled = false;
	spin_unlock_irqrestore(&local_clock_reg_lock, flags);
}

static void rcg_clk_unprepare(struct clk *c)
{
	struct rcg_clk *rcg = to_rcg_clk(c);
	rcg->prepared = false;
}

/*
 * Frequency-related functions
 */

/* Set a clock to an exact rate. */
static int rcg_clk_set_rate(struct clk *c, unsigned long rate)
{
	struct rcg_clk *rcg = to_rcg_clk(c);
	struct clk_freq_tbl *nf, *cf;
	struct clk *chld;
	int rc = 0;
	unsigned long flags;

	for (nf = rcg->freq_tbl; nf->freq_hz != FREQ_END
			&& nf->freq_hz != rate; nf++)
		;

	if (nf->freq_hz == FREQ_END)
		return -EINVAL;

	cf = rcg->current_freq;

	/* Enable source clock dependency for the new frequency */
	if (rcg->prepared) {
		rc = clk_prepare(nf->src_clk);
		if (rc)
			return rc;

	}

	spin_lock_irqsave(&c->lock, flags);
	if (rcg->enabled) {
		rc = clk_enable(nf->src_clk);
		if (rc) {
			spin_unlock_irqrestore(&c->lock, flags);
			clk_unprepare(nf->src_clk);
			return rc;
		}
	}

	spin_lock(&local_clock_reg_lock);

	/* Disable branch if clock isn't dual-banked with a glitch-free MUX. */
	if (!rcg->bank_info) {
		/* Disable all branches to prevent glitches. */
		list_for_each_entry(chld, &rcg->c.children, siblings) {
			struct branch_clk *x = to_branch_clk(chld);
			/*
			 * We don't need to grab the child's lock because
			 * we hold the local_clock_reg_lock and 'enabled' is
			 * only modified within lock.
			 */
			if (x->enabled)
				__branch_disable_reg(&x->b, x->c.dbg_name);
		}
		if (rcg->enabled)
			__rcg_clk_disable_reg(rcg);
	}

	/* Perform clock-specific frequency switch operations. */
	BUG_ON(!rcg->set_rate);
	rcg->set_rate(rcg, nf);

	/*
	 * Current freq must be updated before __rcg_clk_enable_reg()
	 * is called to make sure the MNCNTR_EN bit is set correctly.
	 */
	rcg->current_freq = nf;

	/* Enable any clocks that were disabled. */
	if (!rcg->bank_info) {
		if (rcg->enabled)
			__rcg_clk_enable_reg(rcg);
		/* Enable only branches that were ON before. */
		list_for_each_entry(chld, &rcg->c.children, siblings) {
			struct branch_clk *x = to_branch_clk(chld);
			if (x->enabled)
				__branch_enable_reg(&x->b, x->c.dbg_name);
		}
	}

	spin_unlock(&local_clock_reg_lock);

	/* Release source requirements of the old freq. */
	if (rcg->enabled)
		clk_disable(cf->src_clk);
	spin_unlock_irqrestore(&c->lock, flags);

	if (rcg->prepared)
		clk_unprepare(cf->src_clk);

	return rc;
}

/* Check if a clock is currently enabled. */
static int rcg_clk_is_enabled(struct clk *c)
{
	return to_rcg_clk(c)->enabled;
}

/* Return a supported rate that's at least the specified rate. */
static long rcg_clk_round_rate(struct clk *c, unsigned long rate)
{
	struct rcg_clk *rcg = to_rcg_clk(c);
	struct clk_freq_tbl *f;

	for (f = rcg->freq_tbl; f->freq_hz != FREQ_END; f++)
		if (f->freq_hz >= rate)
			return f->freq_hz;

	return -EPERM;
}

/* Return the nth supported frequency for a given clock. */
static int rcg_clk_list_rate(struct clk *c, unsigned n)
{
	struct rcg_clk *rcg = to_rcg_clk(c);

	if (!rcg->freq_tbl || rcg->freq_tbl->freq_hz == FREQ_END)
		return -ENXIO;

	return (rcg->freq_tbl + n)->freq_hz;
}

static struct clk *rcg_clk_get_parent(struct clk *c)
{
	return to_rcg_clk(c)->current_freq->src_clk;
}

/* Disable hw clock gating if not set at boot */
enum handoff branch_handoff(struct branch *b, struct clk *c)
{
	if (!branch_in_hwcg_mode(b)) {
		b->hwcg_mask = 0;
		if (b->ctl_reg && readl_relaxed(b->ctl_reg) & b->en_mask)
			return HANDOFF_ENABLED_CLK;
	}
	return HANDOFF_DISABLED_CLK;
}

static enum handoff branch_clk_handoff(struct clk *c)
{
	struct branch_clk *br = to_branch_clk(c);
	return branch_handoff(&br->b, &br->c);
}

static enum handoff rcg_clk_handoff(struct clk *c)
{
	struct rcg_clk *rcg = to_rcg_clk(c);
	uint32_t ctl_val, ns_val, md_val, ns_mask;
	struct clk_freq_tbl *freq;
	enum handoff ret;

	ctl_val = readl_relaxed(rcg->b.ctl_reg);
	ret = branch_handoff(&rcg->b, &rcg->c);
	if (ret == HANDOFF_DISABLED_CLK)
		return HANDOFF_DISABLED_CLK;

	if (rcg->bank_info) {
		const struct bank_masks *bank_masks = rcg->bank_info;
		const struct bank_mask_info *bank_info;
		if (!(ctl_val & bank_masks->bank_sel_mask))
			bank_info = &bank_masks->bank0_mask;
		else
			bank_info = &bank_masks->bank1_mask;

		ns_mask = bank_info->ns_mask;
		md_val = bank_info->md_reg ?
				readl_relaxed(bank_info->md_reg) : 0;
	} else {
		ns_mask = rcg->ns_mask;
		md_val = rcg->md_reg ? readl_relaxed(rcg->md_reg) : 0;
	}
	if (!ns_mask)
		return HANDOFF_UNKNOWN_RATE;
	ns_val = readl_relaxed(rcg->ns_reg) & ns_mask;
	for (freq = rcg->freq_tbl; freq->freq_hz != FREQ_END; freq++) {
		if ((freq->ns_val & ns_mask) == ns_val &&
		    (!freq->md_val || freq->md_val == md_val))
			break;
	}
	if (freq->freq_hz == FREQ_END)
		return HANDOFF_UNKNOWN_RATE;

	rcg->current_freq = freq;
	c->rate = freq->freq_hz;

	return HANDOFF_ENABLED_CLK;
}

struct clk_ops clk_ops_empty;

struct fixed_clk gnd_clk = {
	.c = {
		.dbg_name = "ground_clk",
		.ops = &clk_ops_empty,
		CLK_INIT(gnd_clk.c),
	},
};

static int branch_clk_enable(struct clk *c)
{
	unsigned long flags;
	struct branch_clk *br = to_branch_clk(c);

	spin_lock_irqsave(&local_clock_reg_lock, flags);
	__branch_enable_reg(&br->b, br->c.dbg_name);
	br->enabled = true;
	spin_unlock_irqrestore(&local_clock_reg_lock, flags);

	return 0;
}

static void branch_clk_disable(struct clk *c)
{
	unsigned long flags;
	struct branch_clk *br = to_branch_clk(c);

	spin_lock_irqsave(&local_clock_reg_lock, flags);
	__branch_disable_reg(&br->b, br->c.dbg_name);
	br->enabled = false;
	spin_unlock_irqrestore(&local_clock_reg_lock, flags);
}

static struct clk *branch_clk_get_parent(struct clk *c)
{
	return to_branch_clk(c)->parent;
}

static int branch_clk_is_enabled(struct clk *c)
{
	return to_branch_clk(c)->enabled;
}

static void branch_enable_hwcg(struct branch *b)
{
	unsigned long flags;
	u32 reg_val;

	spin_lock_irqsave(&local_clock_reg_lock, flags);
	reg_val = readl_relaxed(b->hwcg_reg);
	reg_val |= b->hwcg_mask;
	writel_relaxed(reg_val, b->hwcg_reg);
	spin_unlock_irqrestore(&local_clock_reg_lock, flags);
}

static void branch_disable_hwcg(struct branch *b)
{
	unsigned long flags;
	u32 reg_val;

	spin_lock_irqsave(&local_clock_reg_lock, flags);
	reg_val = readl_relaxed(b->hwcg_reg);
	reg_val &= ~b->hwcg_mask;
	writel_relaxed(reg_val, b->hwcg_reg);
	spin_unlock_irqrestore(&local_clock_reg_lock, flags);
}

static void branch_clk_enable_hwcg(struct clk *c)
{
	branch_enable_hwcg(&to_branch_clk(c)->b);
}

static void branch_clk_disable_hwcg(struct clk *c)
{
	branch_disable_hwcg(&to_branch_clk(c)->b);
}

static int branch_set_flags(struct branch *b, unsigned flags)
{
	unsigned long irq_flags;
	u32 reg_val;
	int ret = 0;

	if (!b->retain_reg)
		return -EPERM;

	spin_lock_irqsave(&local_clock_reg_lock, irq_flags);
	reg_val = readl_relaxed(b->retain_reg);
	switch (flags) {
	case CLKFLAG_RETAIN:
		reg_val |= b->retain_mask;
		break;
	case CLKFLAG_NORETAIN:
		reg_val &= ~b->retain_mask;
		break;
	default:
		ret = -EINVAL;
	}
	writel_relaxed(reg_val, b->retain_reg);
	spin_unlock_irqrestore(&local_clock_reg_lock, irq_flags);

	return ret;
}

static int branch_clk_set_flags(struct clk *clk, unsigned flags)
{
	return branch_set_flags(&to_branch_clk(clk)->b, flags);
}

static int branch_clk_in_hwcg_mode(struct clk *c)
{
	return branch_in_hwcg_mode(&to_branch_clk(c)->b);
}

static void rcg_clk_enable_hwcg(struct clk *c)
{
	branch_enable_hwcg(&to_rcg_clk(c)->b);
}

static void rcg_clk_disable_hwcg(struct clk *c)
{
	branch_disable_hwcg(&to_rcg_clk(c)->b);
}

static int rcg_clk_in_hwcg_mode(struct clk *c)
{
	return branch_in_hwcg_mode(&to_rcg_clk(c)->b);
}

static int rcg_clk_set_flags(struct clk *clk, unsigned flags)
{
	return branch_set_flags(&to_rcg_clk(clk)->b, flags);
}

int branch_reset(struct branch *b, enum clk_reset_action action)
{
	int ret = 0;
	u32 reg_val;
	unsigned long flags;

	if (!b->reset_reg)
		return -EPERM;

	/* Disable hw gating when asserting a reset */
	if (b->hwcg_mask && action == CLK_RESET_ASSERT)
		branch_disable_hwcg(b);

	spin_lock_irqsave(&local_clock_reg_lock, flags);
	/* Assert/Deassert reset */
	reg_val = readl_relaxed(b->reset_reg);
	switch (action) {
	case CLK_RESET_ASSERT:
		reg_val |= b->reset_mask;
		break;
	case CLK_RESET_DEASSERT:
		reg_val &= ~b->reset_mask;
		break;
	default:
		ret = -EINVAL;
	}
	writel_relaxed(reg_val, b->reset_reg);
	spin_unlock_irqrestore(&local_clock_reg_lock, flags);

	/* Enable hw gating when deasserting a reset */
	if (b->hwcg_mask && action == CLK_RESET_DEASSERT)
		branch_enable_hwcg(b);
	/* Make sure write is issued before returning. */
	mb();
	return ret;
}

static int branch_clk_reset(struct clk *c, enum clk_reset_action action)
{
	return branch_reset(&to_branch_clk(c)->b, action);
}

struct clk_ops clk_ops_branch = {
	.enable = branch_clk_enable,
	.disable = branch_clk_disable,
	.enable_hwcg = branch_clk_enable_hwcg,
	.disable_hwcg = branch_clk_disable_hwcg,
	.in_hwcg_mode = branch_clk_in_hwcg_mode,
	.is_enabled = branch_clk_is_enabled,
	.reset = branch_clk_reset,
	.get_parent = branch_clk_get_parent,
	.handoff = branch_clk_handoff,
	.set_flags = branch_clk_set_flags,
};

struct clk_ops clk_ops_reset = {
	.reset = branch_clk_reset,
};

static int rcg_clk_reset(struct clk *c, enum clk_reset_action action)
{
	return branch_reset(&to_rcg_clk(c)->b, action);
}

struct clk_ops clk_ops_rcg = {
	.prepare = rcg_clk_prepare,
	.enable = rcg_clk_enable,
	.disable = rcg_clk_disable,
	.unprepare = rcg_clk_unprepare,
	.enable_hwcg = rcg_clk_enable_hwcg,
	.disable_hwcg = rcg_clk_disable_hwcg,
	.in_hwcg_mode = rcg_clk_in_hwcg_mode,
	.handoff = rcg_clk_handoff,
	.set_rate = rcg_clk_set_rate,
	.list_rate = rcg_clk_list_rate,
	.is_enabled = rcg_clk_is_enabled,
	.round_rate = rcg_clk_round_rate,
	.reset = rcg_clk_reset,
	.get_parent = rcg_clk_get_parent,
	.set_flags = rcg_clk_set_flags,
};

static int cdiv_clk_enable(struct clk *c)
{
	unsigned long flags;
	struct cdiv_clk *cdiv = to_cdiv_clk(c);

	spin_lock_irqsave(&local_clock_reg_lock, flags);
	__branch_enable_reg(&cdiv->b, cdiv->c.dbg_name);
	spin_unlock_irqrestore(&local_clock_reg_lock, flags);

	return 0;
}

static void cdiv_clk_disable(struct clk *c)
{
	unsigned long flags;
	struct cdiv_clk *cdiv = to_cdiv_clk(c);

	spin_lock_irqsave(&local_clock_reg_lock, flags);
	__branch_disable_reg(&cdiv->b, cdiv->c.dbg_name);
	spin_unlock_irqrestore(&local_clock_reg_lock, flags);
}

static int cdiv_clk_set_rate(struct clk *c, unsigned long rate)
{
	struct cdiv_clk *cdiv = to_cdiv_clk(c);
	u32 reg_val;

	if (rate > cdiv->max_div)
		return -EINVAL;

	spin_lock(&local_clock_reg_lock);
	reg_val = readl_relaxed(cdiv->ns_reg);
	reg_val &= ~(cdiv->ext_mask | (cdiv->max_div - 1) << cdiv->div_offset);
	/* Non-zero rates mean set a divider, zero means use external input */
	if (rate)
		reg_val |= (rate - 1) << cdiv->div_offset;
	else
		reg_val |= cdiv->ext_mask;
	writel_relaxed(reg_val, cdiv->ns_reg);
	spin_unlock(&local_clock_reg_lock);

	cdiv->cur_div = rate;
	return 0;
}

static unsigned long cdiv_clk_get_rate(struct clk *c)
{
	return to_cdiv_clk(c)->cur_div;
}

static long cdiv_clk_round_rate(struct clk *c, unsigned long rate)
{
	return rate > to_cdiv_clk(c)->max_div ? -EPERM : rate;
}

static int cdiv_clk_list_rate(struct clk *c, unsigned n)
{
	return n > to_cdiv_clk(c)->max_div ? -ENXIO : n;
}

static enum handoff cdiv_clk_handoff(struct clk *c)
{
	struct cdiv_clk *cdiv = to_cdiv_clk(c);
	enum handoff ret;
	u32 reg_val;

	ret = branch_handoff(&cdiv->b, &cdiv->c);
	if (ret == HANDOFF_DISABLED_CLK)
		return ret;

	reg_val = readl_relaxed(cdiv->ns_reg);
	if (reg_val & cdiv->ext_mask) {
		cdiv->cur_div = 0;
	} else {
		reg_val >>= cdiv->div_offset;
		cdiv->cur_div = (reg_val & (cdiv->max_div - 1)) + 1;
	}

	return HANDOFF_ENABLED_CLK;
}

static void cdiv_clk_enable_hwcg(struct clk *c)
{
	branch_enable_hwcg(&to_cdiv_clk(c)->b);
}

static void cdiv_clk_disable_hwcg(struct clk *c)
{
	branch_disable_hwcg(&to_cdiv_clk(c)->b);
}

static int cdiv_clk_in_hwcg_mode(struct clk *c)
{
	return branch_in_hwcg_mode(&to_cdiv_clk(c)->b);
}

struct clk_ops clk_ops_cdiv = {
	.enable = cdiv_clk_enable,
	.disable = cdiv_clk_disable,
	.in_hwcg_mode = cdiv_clk_in_hwcg_mode,
	.enable_hwcg = cdiv_clk_enable_hwcg,
	.disable_hwcg = cdiv_clk_disable_hwcg,
	.handoff = cdiv_clk_handoff,
	.set_rate = cdiv_clk_set_rate,
	.get_rate = cdiv_clk_get_rate,
	.list_rate = cdiv_clk_list_rate,
	.round_rate = cdiv_clk_round_rate,
};