100/*
 * OF helpers for the GPIO API
 *
 * Copyright (c) 2007-2008  MontaVista Software, Inc.
 *
 * Author: Anton Vorontsov <avorontsov@ru.mvista.com>
 *
 * 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/device.h>
#include <linux/errno.h>
#include <linux/module.h>
#include <linux/io.h>
#include <linux/gpio.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_gpio.h>
#include <linux/pinctrl/pinctrl.h>
#include <linux/slab.h>

/* Private data structure for of_gpiochip_find_and_xlate */
struct gg_data {
	enum of_gpio_flags *flags;
	struct of_phandle_args gpiospec;

	int out_gpio;
};

/* Private function for resolving node pointer to gpio_chip */
static int of_gpiochip_find_and_xlate(struct gpio_chip *gc, void *data)
{
	struct gg_data *gg_data = data;
	int ret;

	if ((gc->of_node != gg_data->gpiospec.np) ||
	    (gc->of_gpio_n_cells != gg_data->gpiospec.args_count) ||
	    (!gc->of_xlate))
		return false;

	ret = gc->of_xlate(gc, &gg_data->gpiospec, gg_data->flags);
	if (ret < 0)
		return false;

	gg_data->out_gpio = ret + gc->base;
	return true;
}

/**
 * of_get_named_gpio_flags() - Get a GPIO number and flags to use with GPIO API
 * @np:		device node to get GPIO from
 * @propname:	property name containing gpio specifier(s)
 * @index:	index of the GPIO
 * @flags:	a flags pointer to fill in
 *
 * Returns GPIO number to use with Linux generic GPIO API, or one of the errno
 * value on the error condition. If @flags is not NULL the function also fills
 * in flags for the GPIO.
 */
int of_get_named_gpio_flags(struct device_node *np, const char *propname,
                           int index, enum of_gpio_flags *flags)
{
	/* Return -EPROBE_DEFER to support probe() functions to be called
	 * later when the GPIO actually becomes available
	 */
	struct gg_data gg_data = { .flags = flags, .out_gpio = -EPROBE_DEFER };
	int ret;

	/* .of_xlate might decide to not fill in the flags, so clear it. */
	if (flags)
		*flags = 0;

	ret = of_parse_phandle_with_args(np, propname, "#gpio-cells", index,
					 &gg_data.gpiospec);
	if (ret) {
		pr_debug("%s: can't parse gpios property\n", __func__);
		return ret;
	}

	gpiochip_find(&gg_data, of_gpiochip_find_and_xlate);

	of_node_put(gg_data.gpiospec.np);
	pr_debug("%s exited with status %d\n", __func__, gg_data.out_gpio);
	return gg_data.out_gpio;
}
EXPORT_SYMBOL(of_get_named_gpio_flags);

/**
 * of_gpio_simple_xlate - translate gpio_spec to the GPIO number and flags
 * @gc:		pointer to the gpio_chip structure
 * @np:		device node of the GPIO chip
 * @gpio_spec:	gpio specifier as found in the device tree
 * @flags:	a flags pointer to fill in
 *
 * This is simple translation function, suitable for the most 1:1 mapped
 * gpio chips. This function performs only one sanity check: whether gpio
 * is less than ngpios (that is specified in the gpio_chip).
 */
int of_gpio_simple_xlate(struct gpio_chip *gc,
			 const struct of_phandle_args *gpiospec, u32 *flags)
{
	/*
	 * We're discouraging gpio_cells < 2, since that way you'll have to
	 * write your own xlate function (that will have to retrive the GPIO
	 * number and the flags from a single gpio cell -- this is possible,
	 * but not recommended).
	 */
	if (gc->of_gpio_n_cells < 2) {
		WARN_ON(1);
		return -EINVAL;
	}

	if (WARN_ON(gpiospec->args_count < gc->of_gpio_n_cells))
		return -EINVAL;

	if (gpiospec->args[0] >= gc->ngpio)
		return -EINVAL;

	if (flags)
		*flags = gpiospec->args[1];

	return gpiospec->args[0];
}
EXPORT_SYMBOL(of_gpio_simple_xlate);

/**
 * of_mm_gpiochip_add - Add memory mapped GPIO chip (bank)
 * @np:		device node of the GPIO chip
 * /*
 * RT-Mutex-tester: scriptable tester for rt mutexes
 *
 * started by Thomas Gleixner:
 *
 *  Copyright (C) 2006, Timesys Corp., Thomas Gleixner <tglx@timesys.com>
 *
 */
#include <linux/kthread.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/smp_lock.h>
#include <linux/spinlock.h>
#include <linux/sysdev.h>
#include <linux/timer.h>
#include <linux/freezer.h>

#include "rtmutex.h"

#define MAX_RT_TEST_THREADS	8
#define MAX_RT_TEST_MUTEXES	8

static spinlock_t rttest_lock;
static atomic_t rttest_event;

struct test_thread_data {
	int			opcode;
	int			opdata;
	int			mutexes[MAX_RT_TEST_MUTEXES];
	int			bkl;
	int			event;
	struct sys_device	sysdev;
};

static struct test_thread_data thread_data[MAX_RT_TEST_THREADS];
static struct task_struct *threads[MAX_RT_TEST_THREADS];
static struct rt_mutex mutexes[MAX_RT_TEST_MUTEXES];

enum test_opcodes {
	RTTEST_NOP = 0,
	RTTEST_SCHEDOT,		/* 1 Sched other, data = nice */
	RTTEST_SCHEDRT,		/* 2 Sched fifo, data = prio */
	RTTEST_LOCK,		/* 3 Lock uninterruptible, data = lockindex */
	RTTEST_LOCKNOWAIT,	/* 4 Lock uninterruptible no wait in wakeup, data = lockindex */
	RTTEST_LOCKINT,		/* 5 Lock interruptible, data = lockindex */
	RTTEST_LOCKINTNOWAIT,	/* 6 Lock interruptible no wait in wakeup, data = lockindex */
	RTTEST_LOCKCONT,	/* 7 Continue locking after the wakeup delay */
	RTTEST_UNLOCK,		/* 8 Unlock, data = lockindex */
	RTTEST_LOCKBKL,		/* 9 Lock BKL */
	RTTEST_UNLOCKBKL,	/* 10 Unlock BKL */
	RTTEST_SIGNAL,		/* 11 Signal other test thread, data = thread id */
	RTTEST_RESETEVENT = 98,	/* 98 Reset event counter */
	RTTEST_RESET = 99,	/* 99 Reset all pending operations */
};

static int handle_op(struct test_thread_data *td, int lockwakeup)
{
	int i, id, ret = -EINVAL;

	switch(td->opcode) {

	case RTTEST_NOP:
		return 0;

	case RTTEST_LOCKCONT:
		td->mutexes[td->opdata] = 1;
		td->event = atomic_add_return(1, &rttest_event);
		return 0;

	case RTTEST_RESET:
		for (i = 0; i < MAX_RT_TEST_MUTEXES; i++) {
			if (td->mutexes[i] == 4) {
				rt_mutex_unlock(&mutexes[i]);
				td->mutexes[i] = 0;
			}
		}

		if (!lockwakeup && td->bkl == 4) {
			unlock_kernel();
			td->bkl = 0;
		}
		return 0;

	case RTTEST_RESETEVENT:
		atomic_set(&rttest_event, 0);
		return 0;

	default:
		if (lockwakeup)
			return ret;
	}

	switch(td->opcode) {

	case RTTEST_LOCK:
	case RTTEST_LOCKNOWAIT:
		id = td->opdata;
		if (id < 0 || id >= MAX_RT_TEST_MUTEXES)
			return ret;

		td->mutexes[id] = 1;
		td->event = atomic_add_return(1, &rttest_event);
		rt_mutex_lock(&mutexes[id]);
		td->event = atomic_add_return(1, &rttest_event);
		td->mutexes[id] = 4;
		return 0;

	case RTTEST_LOCKINT:
	case RTTEST_LOCKINTNOWAIT:
		id = td->opdata;
		if (id < 0 || id >= MAX_RT_TEST_MUTEXES)
			return ret;

		td->mutexes[id] = 1;
		td->event = atomic_add_return(1, &rttest_event);
		ret = rt_mutex_lock_interruptible(&mutexes[id], 0);
		td->event = atomic_add_return(1, &rttest_event);
		td->mutexes[id] = ret ? 0 : 4;
		return ret ? -EINTR : 0;

	case RTTEST_UNLOCK:
		id = td->opdata;
		if (id < 0 || id >= MAX_RT_TEST_MUTEXES || td->mutexes[id] != 4)
			return ret;

		td->event = atomic_add_return(1, &rttest_event);
		rt_mutex_unlock(&mutexes[id]);
		td->event = atomic_add_return(1, &rttest_event);
		td->mutexes[id] = 0;
		return 0;

	case RTTEST_LOCKBKL:
		if (td->bkl)
			return 0;
		td->bkl = 1;
		lock_kernel();
		td->bkl = 4;
		return 0;

	case RTTEST_UNLOCKBKL:
		if (td->bkl != 4)
			break;
		unlock_kernel();
		td->bkl = 0;
		return 0;

	default:
		break;
	}
	return ret;
}

/*
 * Schedule replacement for rtsem_down(). Only called for threads with
 * PF_MUTEX_TESTER set.
 *
 * This allows us to have finegrained control over the event flow.
 *
 */
void schedule_rt_mutex_test(struct rt_mutex *mutex)
{
	int tid, op, dat;
	struct test_thread_data *td;

	/* We have to lookup the task */
	for (tid = 0; tid < MAX_RT_TEST_THREADS; tid++) {
		if (threads[tid] == current)
			break;
	}

	BUG_ON(tid == MAX_RT_TEST_THREADS);

	td = &thread_data[tid];

	op = td->opcode;
	dat = td->opdata;

	switch (op) {
	case RTTEST_LOCK:
	case RTTEST_LOCKINT:
	case RTTEST_LOCKNOWAIT:
	case RTTEST_LOCKINTNOWAIT:
		if (mutex != &mutexes[dat])
			break;

		if (td->mutexes[dat] != 1)
			break;

		td->mutexes[dat] = 2;
		td->event = atomic_add_return(1, &rttest_event);
		break;

	case RTTEST_LOCKBKL:
	default:
		break;
	}

	schedule();


	switch (op) {
	case RTTEST_LOCK:
	case RTTEST_LOCKINT:
		if (mutex != &mutexes[dat])
			return;

		if (td->mutexes[dat] != 2)
			return;

		td->mutexes[dat] = 3;
		td->event = atomic_add_return(1, &rttest_event);
		break;

	case RTTEST_LOCKNOWAIT:
	case RTTEST_LOCKINTNOWAIT:
		if (mutex != &mutexes[dat])
			return;

		if (td->mutexes[dat] != 2)
			return;

		td->mutexes[dat] = 1;
		td->event = atomic_add_return(1, &rttest_event);
		return;

	case RTTEST_LOCKBKL:
		return;
	default:
		return;
	}

	td->opcode = 0;

	for (;;) {
		set_current_state(TASK_INTERRUPTIBLE);

		if (td->opcode > 0) {
			int ret;

			set_current_state(TASK_RUNNING);
			ret = handle_op(td, 1);
			set_current_state(TASK_INTERRUPTIBLE);
			if (td->opcode == RTTEST_LOCKCONT)
				break;
			td->opcode = ret;
		}

		/* Wait for the next command to be executed */
		schedule();
	}

	/* Restore previous command and data */
	td->opcode = op;
	td->opdata = dat;
}

static int test_func(void *data)
{
	struct test_thread_data *td = data;
	int ret;

	current->flags |= PF_MUTEX_TESTER;
	set_freezable();
	allow_signal(SIGHUP);

	for(;;) {

		set_current_state(TASK_INTERRUPTIBLE);

		if (td->opcode > 0) {
			set_current_state(TASK_RUNNING);
			ret = handle_op(td, 0);
			set_current_state(TASK_INTERRUPTIBLE);
			td->opcode = ret;
		}

		/* Wait for the next command to be executed */
		schedule();
		try_to_freeze();

		if (signal_pending(current))
			flush_signals(current);

		if(kthread_should_stop())
			break;
	}
	return 0;
}

/**
 * sysfs_test_command - interface for test commands
 * @dev:	thread reference
 * @buf:	command for actual step
 * @count:	length of buffer
 *
 * command syntax:
 *
 * opcode:data
 */
static ssize_t sysfs_test_command(struct sys_device *dev, struct sysdev_attribute *attr,
				  const char *buf, size_t count)
{
	struct sched_param schedpar;
	struct test_thread_data *td;
	char cmdbuf[32];
	int op, dat, tid, ret;

	td = container_of(dev, struct test_thread_data, sysdev);
	tid = td->sysdev.id;

	/* strings from sysfs write are not 0 terminated! */
	if (count >= sizeof(cmdbuf))
		return -EINVAL;

	/* strip of \n: */
	if (buf[count-1] == '\n')
		count--;
	if (count < 1)
		return -EINVAL;

	memcpy(cmdbuf, buf, count);
	cmdbuf[count] = 0;

	if (sscanf(cmdbuf, "%d:%d", &op, &dat) != 2)
		return -EINVAL;

	switch (op) {
	case RTTEST_SCHEDOT:
		schedpar.sched_priority = 0;
		ret = sched_setscheduler(threads[tid], SCHED_NORMAL, &schedpar);
		if (ret)
			return ret;
		set_user_nice(current, 0);
		break;

	case RTTEST_SCHEDRT:
		schedpar.sched_priority = dat;
		ret = sched_setscheduler(threads[tid], SCHED_FIFO, &schedpar);
		if (ret)
			return ret;
		break;

	case RTTEST_SIGNAL:
		send_sig(SIGHUP, threads[tid], 0);
		break;

	default:
		if (td->opcode > 0)
			return -EBUSY;
		td->opdata = dat;
		td->opcode = op;
		wake_up_process(threads[tid]);
	}

	return count;
}

/**
 * sysfs_test_status - sysfs interface for rt tester
 * @dev:	thread to query
 * @buf:	char buffer to be filled with thread status info
 */
static ssize_t sysfs_test_status(struct sys_device *dev, struct sysdev_attribute *attr,
				 char *buf)
{
	struct test_thread_data *td;
	struct task_struct *tsk;
	char *curr = buf;
	int i;

	td = container_of(dev, struct test_thread_data, sysdev);
	tsk = threads[td->sysdev.id];

	spin_lock(&rttest_lock);

	curr += sprintf(curr,
		"O: %4d, E:%8d, S: 0x%08lx, P: %4d, N: %4d, B: %p, K: %d, M:",
		td->opcode, td->event, tsk->state,
			(MAX_RT_PRIO - 1) - tsk->prio,
			(MAX_RT_PRIO - 1) - tsk->normal_prio,
		tsk->pi_blocked_on, td->bkl);

	for (i = MAX_RT_TEST_MUTEXES - 1; i >=0 ; i--)
		curr += sprintf(curr, "%d", td->mutexes[i]);

	spin_unlock(&rttest_lock);

	curr += sprintf(curr, ", T: %p, R: %p\n", tsk,
			mutexes[td->sysdev.id].owner);

	return curr - buf;
}

static SYSDEV_ATTR(status, 0600, sysfs_test_status, NULL);
static SYSDEV_ATTR(command, 0600, NULL, sysfs_test_command);

static struct sysdev_class rttest_sysclass = {
	.name = "rttest",
};

static int init_test_thread(int id)
{
	thread_data[id].sysdev.cls = &rttest_sysclass;
	thread_data[id].sysdev.id = id;

	threads[id] = kthread_run(test_func, &thread_data[id], "rt-test-%d", id);
	if (IS_ERR(threads[id]))
		return PTR_ERR(threads[id]);

	return sysdev_register(&thread_data[id].sysdev);
}

static int init_rttest(void)
{
	int ret, i;

	spin_lock_init(&rttest_lock);

	for (i = 0; i < MAX_RT_TEST_MUTEXES; i++)
		rt_mutex_init(&mutexes[i]);

	ret = sysdev_class_register(&rttest_sysclass);
	if (ret)
		return ret;

	for (i = 0; i < MAX_RT_TEST_THREADS; i++) {
		ret = init_test_thread(i);
		if (ret)
			break;
		ret = sysdev_create_file(&thread_data[i].sysdev, &attr_status);
		if (ret)
			break;
		ret = sysdev_create_file(&thread_data[i].sysdev, &attr_command);
		if (ret)
			break;
	}

	printk("Initializing RT-Tester: %s\n", ret ? "Failed" : "OK" );

	return ret;
}

device_initcall(init_rttest);