/*
 * linux/arch/arm/mach-omap2/mux.c
 *
 * OMAP2, OMAP3 and OMAP4 pin multiplexing configurations
 *
 * Copyright (C) 2004 - 2010 Texas Instruments Inc.
 * Copyright (C) 2003 - 2008 Nokia Corporation
 *
 * Written by Tony Lindgren
 *
 * 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.
 *
 * 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.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 */
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/list.h>
#include <linux/slab.h>
#include <linux/ctype.h>
#include <linux/debugfs.h>
#include <linux/seq_file.h>
#include <linux/uaccess.h>
#include <linux/irq.h>
#include <linux/interrupt.h>


#include "omap_hwmod.h"

#include "soc.h"
#include "control.h"
#include "mux.h"
#include "prm.h"
#include "common.h"

#define OMAP_MUX_BASE_OFFSET		0x30	/* Offset from CTRL_BASE */
#define OMAP_MUX_BASE_SZ		0x5ca

struct omap_mux_entry {
	struct omap_mux		mux;
	struct list_head	node;
};

static LIST_HEAD(mux_partitions);
static DEFINE_MUTEX(muxmode_mutex);

struct omap_mux_partition *omap_mux_get(const char *name)
{
	struct omap_mux_partition *partition;

	list_for_each_entry(partition, &mux_partitions, node) {
		if (!strcmp(name, partition->name))
			return partition;
	}

	return NULL;
}

u16 omap_mux_read(struct omap_mux_partition *partition, u16 reg)
{
	if (partition->flags & OMAP_MUX_REG_8BIT)
		return __raw_readb(partition->base + reg);
	else
		return __raw_readw(partition->base + reg);
}

void omap_mux_write(struct omap_mux_partition *partition, u16 val,
			   u16 reg)
{
	if (partition->flags & OMAP_MUX_REG_8BIT)
		__raw_writeb(val, partition->base + reg);
	else
		__raw_writew(val, partition->base + reg);
}

void omap_mux_write_array(struct omap_mux_partition *partition,
				 struct omap_board_mux *board_mux)
{
	if (!board_mux)
		return;

	while (board_mux->reg_offset != OMAP_MUX_TERMINATOR) {
		omap_mux_write(partition, board_mux->value,
			       board_mux->reg_offset);
		board_mux++;
	}
}

#ifdef CONFIG_OMAP_MUX

static char *omap_mux_options;

static int __init _omap_mux_init_gpio(struct omap_mux_partition *partition,
				      int gpio, int val)
{
	struct omap_mux_entry *e;
	struct omap_mux *gpio_mux = NULL;
	u16 old_mode;
	u16 mux_mode;
	int found = 0;
	struct list_head *muxmodes = &partition->muxmodes;

	if (!gpio)
		return -EINVAL;

	list_for_each_entry(e, muxmodes, node) {
		struct omap_mux *m = &e->mux;
		if (gpio == m->gpio) {
			gpio_mux = m;
			found++;
		}
	}

	if (found == 0) {
		pr_err("%s: Could not set gpio%i\n", __func__, gpio);
		return -ENODEV;
	}

	if (found > 1) {
		pr_info("%s: Multiple gpio paths (%d) for gpio%i\n", __func__,
			found, gpio);
		return -EINVAL;
	}

	old_mode = omap_mux_read(partition, gpio_mux->reg_offset);
	mux_mode = val & ~(OMAP_MUX_NR_MODES - 1);
	mux_mode |= partition->gpio;
	pr_debug("%s: Setting signal %s.gpio%i 0x%04x -> 0x%04x\n", __func__,
		 gpio_mux->muxnames[0], gpio, old_mode, mux_mode);
	omap_mux_write(partition, mux_mode, gpio_mux->reg_offset);

	return 0;
}

int __init omap_mux_init_gpio(int gpio, int val)
{
	struct omap_mux_partition *partition;
	int ret;

	list_for_each_entry(partition, &mux_partitions, node) {
		ret = _omap_mux_init_gpio(partition, gpio, val);
		if (!ret)
			return ret;
	}

	return -ENODEV;
}

static int __init _omap_mux_get_by_name(struct omap_mux_partition *partition,
					const char *muxname,
					struct omap_mux **found_mux)
{
	struct omap_mux *mux = NULL;
	struct omap_mux_entry *e;
	const char *mode_name;
	int found = 0, found_mode = 0, mode0_len = 0;
	struct list_head *muxmodes = &partition->muxmodes;

	mode_name = strchr(muxname, '.');
	if (mode_name) {
		mode0_len = strlen(muxname) - strlen(mode_name);
		mode_name++;
	} else {
		mode_name = muxname;
	}

	list_for_each_entry(e, muxmodes, node) {
		char *m0_entry;
		int i;

		mux = &e->mux;
		m0_entry = mux->muxnames[0];

		/* First check for full name in mode0.muxmode format */
		if (mode0_len && strncmp(muxname, m0_entry, mode0_len))
			continue;

		/* Then check for muxmode only */
		for (i = 0; i < OMAP_MUX_NR_MODES; i++) {
			char *mode_cur = mux->muxnames[i];

			if (!mode_cur)
				continue;

			if (!strcmp(mode_name, mode_cur)) {
				*found_mux = mux;
				found++;
				found_mode = i;
			}
		}
	}

	if (found == 1) {
		return found_mode;
	}

	if (found > 1) {
		pr_err("%s: Multiple signal paths (%i) for %s\n", __func__,
		       found, muxname);
		return -EINVAL;
	}

	pr_err("%s: Could not find signal %s\n", __func__, muxname);

	return -ENODEV;
}

int __init omap_mux_get_by_name(const char *muxname,
			struct omap_mux_partition **found_partition,
			struct omap_mux **found_mux)
{
	struct omap_mux_partition *partition;

	list_for_each_entry(partition, &mux_partitions, node) {
		struct omap_mux *mux = NULL;
		int mux_mode = _omap_mux_get_by_name(partition, muxname, &mux);
		if (mux_mode < 0)
			continue;

		*found_partition = partition;
		*found_mux = mux;

		return mux_mode;
	}

	return -ENODEV;
}

int __init omap_mux_init_signal(const char *muxname, int val)
{
	struct omap_mux_partition *partition = NULL;
	struct omap_mux *mux = NULL;
	u16 old_mode;
	int mux_mode;

	mux_mode = omap_mux_get_by_name(muxname, &partition, &mux);
	if (mux_mode < 0 || !mux)
		return mux_mode;

	old_mode = omap_mux_read(partition, mux->reg_offset);
	mux_mode |= val;
	pr_debug("%s: Setting signal %s 0x%04x -> 0x%04x\n",
			 __func__, muxname, old_mode, mux_mode);
	omap_mux_write(partition, mux_mode, mux->reg_offset);

	return 0;
}

struct omap_hwmod_mux_info * __init
omap_hwmod_mux_init(struct omap_device_pad *bpads, int nr_pads)
{
	struct omap_hwmod_mux_info *hmux;
	int i, nr_pads_dynamic = 0;

	if (!bpads || nr_pads < 1)
		return NULL;

	hmux = kzalloc(sizeof(struct omap_hwmod_mux_info), GFP_KERNEL);
	if (!hmux)
		goto err1;

	hmux->nr_pads = nr_pads;

	hmux->pads = kzalloc(sizeof(struct omap_device_pad) *
				nr_pads, GFP_KERNEL);
	if (!hmux->pads)
		goto err2;

	for (i = 0; i < hmux->nr_pads; i++) {
		struct omap_mux_partition *partition;
		struct omap_device_pad *bpad = &bpads[i], *pad = &hmux->pads[i];
		struct omap_mux *mux;
		int mux_mode;

		mux_mode = omap_mux_get_by_name(bpad->name, &partition, &mux);
		if (mux_mode < 0)
			goto err3;
		if (!pad->partition)
			pad->partition = partition;
		if (!pad->mux)
			pad->mux = mux;

		pad->name = kzalloc(strlen(bpad->name) + 1, GFP_KERNEL);
		if (!pad->name) {
			int j;

			for (j = i - 1; j >= 0; j--)
				kfree(hmux->pads[j].name);
			goto err3;
		}
		strcpy(pad->name, bpad->name);

		pad->flags = bpad->flags;
		pad->enable = bpad->enable;
		pad->idle = bpad->idle;
		pad->off = bpad->off;

		if (pad->flags &
		    (OMAP_DEVICE_PAD_REMUX | OMAP_DEVICE_PAD_WAKEUP))
			nr_pads_dynamic++;

		pr_debug("%s: Initialized %s\n", __func__, pad->name);
	}

	if (!nr_pads_dynamic)
		return hmux;

	/*
	 * Add pads that need dynamic muxing into a separate list
	 */

	hmux->nr_pads_dynamic = nr_pads_dynamic;
	hmux->pads_dynamic = kzalloc(sizeof(struct omap_device_pad *) *
					nr_pads_dynamic, GFP_KERNEL);
	if (!hmux->pads_dynamic) {
		pr_err("%s: Could not allocate dynamic pads\n", __func__);
		return hmux;
	}

	nr_pads_dynamic = 0;
	for (i = 0; i < hmux->nr_pads; i++) {
		struct omap_device_pad *pad = &hmux->pads[i];

		if (pad->flags &
		    (OMAP_DEVICE_PAD_REMUX | OMAP_DEVICE_PAD_WAKEUP)) {
			pr_debug("%s: pad %s tagged dynamic\n",
					__func__, pad->name);
			hmux->pads_dynamic[nr_pads_dynamic] = pad;
			nr_pads_dynamic++;
		}
	}

	return hmux;

err3:
	kfree(hmux->pads);
err2:
	kfree(hmux);
err1:
	pr_err("%s: Could not allocate device mux entry\n", __func__);

	return NULL;
}

/**
 * omap_hwmod_mux_scan_wakeups - omap hwmod scan wakeup pads
 * @hmux: Pads for a hwmod
 * @mpu_irqs: MPU irq array for a hwmod
 *
 * Scans the wakeup status of pads for a single hwmod.  If an irq
 * array is defined for this mux, the parser will call the registered
 * ISRs for corresponding pads, otherwise the parser will stop at the
 * first wakeup active pad and return.  Returns true if there is a
 * pending and non-served wakeup event for the mux, otherwise false.
 */
static bool omap_hwmod_mux_scan_wakeups(struct omap_hwmod_mux_info *hmux,
		struct omap_hwmod_irq_info *mpu_irqs)
{
	int i, irq;
	unsigned int val;
	u32 handled_irqs = 0;

	for (i = 0; i < hmux->nr_pads_dynamic; i++) {
		struct omap_device_pad *pad = hmux->pads_dynamic[i];

		if (!(pad->flags & OMAP_DEVICE_PAD_WAKEUP) ||
		    !(pad->idle & OMAP_WAKEUP_EN))
			continue;

		val = omap_mux_read(pad->partition, pad->mux->reg_offset);
		if (!(val & OMAP_WAKEUP_EVENT))
			continue;

		if (!hmux->irqs)
			return true;

		irq = hmux->irqs[i];
		/* make sure we only handle each irq once */
		if (handled_irqs & 1 << irq)
			continue;

		handled_irqs |= 1 << irq;

		generic_handle_irq(mpu_irqs[irq].irq);
	}

	return false;
}

/**
 * _omap_hwmod_mux_handle_irq - Process wakeup events for a single hwmod
 *
 * Checks a single hwmod for every wakeup capable pad to see if there is an
 * active wakeup event. If this is the case, call the corresponding ISR.
 */
static int _omap_hwmod_mux_handle_irq(struct omap_hwmod *oh, void *data)
{
	if (!oh->mux || !oh->mux->enabled)
		return 0;
	if (omap_hwmod_mux_scan_wakeups(oh->mux, oh->mpu_irqs))
		generic_handle_irq(oh->mpu_irqs[0].irq);
	return 0;
}

/**
 * omap_hwmod_mux_handle_irq - Process pad wakeup irqs.
 *
 * Calls a function for each registered omap_hwmod to check
 * pad wakeup statuses.
 */
static irqreturn_t omap_hwmod_mux_handle_irq(int irq, void *unused)
{
	omap_hwmod_for_each(_omap_hwmod_mux_handle_irq, NULL);
	return IRQ_HANDLED;
}

/* Assumes the calling function takes care of locking */
void omap_hwmod_mux(struct omap_hwmod_mux_info *hmux, u8 state)
{
	int i;

	/* Runtime idling of dynamic pads */
	if (state == _HWMOD_STATE_IDLE && hmux->enabled) {
		for (i = 0; i < hmux->nr_pads_dynamic; i++) {
			struct omap_device_pad *pad = hmux->pads_dynamic[i];
			int val = -EINVAL;

			val = pad->idle;
			omap_mux_write(pad->partition, val,
					pad->mux->reg_offset);
		}

		return;
	}

	/* Runtime enabling of dynamic pads */
	if ((state == _HWMOD_STATE_ENABLED) && hmux->pads_dynamic
					&& hmux->enabled) {
		for (i = 0; i < hmux->nr_pads_dynamic; i++) {
			struct omap_device_pad *pad = hmux->pads_dynamic[i];
			int val = -EINVAL;

			val = pad->enable;
			omap_mux_write(pad->partition, val,
					pad->mux->reg_offset);
		}

		return;
	}

	/* Enabling or disabling of all pads */
	for (i = 0; i < hmux->nr_pads; i++) {
		struct omap_device_pad *pad = &hmux->pads[i];
		int flags, val = -EINVAL;

		flags = pad->flags;

		switch (state) {
		case _HWMOD_STATE_ENABLED:
			val = pad->enable;
			pr_debug("%s: Enabling %s %x\n", __func__,
					pad->name, val);
			break;
		case _HWMOD_STATE_DISABLED:
			/* Use safe mode unless OMAP_DEVICE_PAD_REMUX */
			if (flags & OMAP_DEVICE_PAD_REMUX)