Revision 8bb9b9a006e8b092be3a14530d8f12cb4cb9428b authored by Greg Kroah-Hartman on 26 November 2014, 19:06:36 UTC, committed by Greg Kroah-Hartman on 26 November 2014, 19:06:36 UTC
Jonathan writes:

Third set of IIO fixes for the 3.18 cycle.

Most of these are fairly standard little fixes, a bmc150 and bmg160 patch
is to make an ABI change to indicated a specific axis in an event rather
than the generic option in the original drivers.  As both of these drivers
are new in this cycle it would be ideal to push this minor change through
even though it isn't strictly a fix.  A couple of other 'fixes' change
defaults for some settings on these new drivers to more intuitive calues.
Looks like some useful feedback has been coming in for this driver
since it was applied.

* IIO_EVENT_CODE_EXTRACT_DIR bit mask was wrong and has been for a while
  0xCF clearly doesn't give a contiguous bitmask.
* kxcjk-1013 range setting was failing to mask out the previous value
  in the register and hence was 'enable only'.
* men_z188 device id table wasn't null terminated.
* bmg160 and bmc150 both failed to correctly handling an error in mode
  setting.
* bmg160 and bmc150 both had a bug in setting the event direction in the
  event spec (leads to an attribute name being incorrect)
* bmg160 defaulted to an open drain output for the interrupt - as a default
  this obviously only works with some interrupt chips - hence change the
  default to push-pull (note this is a new driver so we aren't going to
  cause any regressions with this change).
* bmc150 had an unintuitive default for the rate of change (motion detector)
  so change it to 0 (new driver so change of default won't cause any
  regressions).
2 parent s 206c5f6 + 9e8e228
Raw File
omap_hwspinlock.c
/*
 * OMAP hardware spinlock driver
 *
 * Copyright (C) 2010 Texas Instruments Incorporated - http://www.ti.com
 *
 * Contact: Simon Que <sque@ti.com>
 *          Hari Kanigeri <h-kanigeri2@ti.com>
 *          Ohad Ben-Cohen <ohad@wizery.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 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.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/bitops.h>
#include <linux/pm_runtime.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/hwspinlock.h>
#include <linux/platform_device.h>

#include "hwspinlock_internal.h"

/* Spinlock register offsets */
#define SYSSTATUS_OFFSET		0x0014
#define LOCK_BASE_OFFSET		0x0800

#define SPINLOCK_NUMLOCKS_BIT_OFFSET	(24)

/* Possible values of SPINLOCK_LOCK_REG */
#define SPINLOCK_NOTTAKEN		(0)	/* free */
#define SPINLOCK_TAKEN			(1)	/* locked */

static int omap_hwspinlock_trylock(struct hwspinlock *lock)
{
	void __iomem *lock_addr = lock->priv;

	/* attempt to acquire the lock by reading its value */
	return (SPINLOCK_NOTTAKEN == readl(lock_addr));
}

static void omap_hwspinlock_unlock(struct hwspinlock *lock)
{
	void __iomem *lock_addr = lock->priv;

	/* release the lock by writing 0 to it */
	writel(SPINLOCK_NOTTAKEN, lock_addr);
}

/*
 * relax the OMAP interconnect while spinning on it.
 *
 * The specs recommended that the retry delay time will be
 * just over half of the time that a requester would be
 * expected to hold the lock.
 *
 * The number below is taken from an hardware specs example,
 * obviously it is somewhat arbitrary.
 */
static void omap_hwspinlock_relax(struct hwspinlock *lock)
{
	ndelay(50);
}

static const struct hwspinlock_ops omap_hwspinlock_ops = {
	.trylock = omap_hwspinlock_trylock,
	.unlock = omap_hwspinlock_unlock,
	.relax = omap_hwspinlock_relax,
};

static int omap_hwspinlock_probe(struct platform_device *pdev)
{
	struct hwspinlock_pdata *pdata = pdev->dev.platform_data;
	struct hwspinlock_device *bank;
	struct hwspinlock *hwlock;
	struct resource *res;
	void __iomem *io_base;
	int num_locks, i, ret;

	if (!pdata)
		return -ENODEV;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!res)
		return -ENODEV;

	io_base = ioremap(res->start, resource_size(res));
	if (!io_base)
		return -ENOMEM;

	/*
	 * make sure the module is enabled and clocked before reading
	 * the module SYSSTATUS register
	 */
	pm_runtime_enable(&pdev->dev);
	ret = pm_runtime_get_sync(&pdev->dev);
	if (ret < 0) {
		pm_runtime_put_noidle(&pdev->dev);
		goto iounmap_base;
	}

	/* Determine number of locks */
	i = readl(io_base + SYSSTATUS_OFFSET);
	i >>= SPINLOCK_NUMLOCKS_BIT_OFFSET;

	/*
	 * runtime PM will make sure the clock of this module is
	 * enabled again iff at least one lock is requested
	 */
	ret = pm_runtime_put(&pdev->dev);
	if (ret < 0)
		goto iounmap_base;

	/* one of the four lsb's must be set, and nothing else */
	if (hweight_long(i & 0xf) != 1 || i > 8) {
		ret = -EINVAL;
		goto iounmap_base;
	}

	num_locks = i * 32; /* actual number of locks in this device */

	bank = kzalloc(sizeof(*bank) + num_locks * sizeof(*hwlock), GFP_KERNEL);
	if (!bank) {
		ret = -ENOMEM;
		goto iounmap_base;
	}

	platform_set_drvdata(pdev, bank);

	for (i = 0, hwlock = &bank->lock[0]; i < num_locks; i++, hwlock++)
		hwlock->priv = io_base + LOCK_BASE_OFFSET + sizeof(u32) * i;

	ret = hwspin_lock_register(bank, &pdev->dev, &omap_hwspinlock_ops,
						pdata->base_id, num_locks);
	if (ret)
		goto reg_fail;

	return 0;

reg_fail:
	kfree(bank);
iounmap_base:
	pm_runtime_disable(&pdev->dev);
	iounmap(io_base);
	return ret;
}

static int omap_hwspinlock_remove(struct platform_device *pdev)
{
	struct hwspinlock_device *bank = platform_get_drvdata(pdev);
	void __iomem *io_base = bank->lock[0].priv - LOCK_BASE_OFFSET;
	int ret;

	ret = hwspin_lock_unregister(bank);
	if (ret) {
		dev_err(&pdev->dev, "%s failed: %d\n", __func__, ret);
		return ret;
	}

	pm_runtime_disable(&pdev->dev);
	iounmap(io_base);
	kfree(bank);

	return 0;
}

static struct platform_driver omap_hwspinlock_driver = {
	.probe		= omap_hwspinlock_probe,
	.remove		= omap_hwspinlock_remove,
	.driver		= {
		.name	= "omap_hwspinlock",
		.owner	= THIS_MODULE,
	},
};

static int __init omap_hwspinlock_init(void)
{
	return platform_driver_register(&omap_hwspinlock_driver);
}
/* board init code might need to reserve hwspinlocks for predefined purposes */
postcore_initcall(omap_hwspinlock_init);

static void __exit omap_hwspinlock_exit(void)
{
	platform_driver_unregister(&omap_hwspinlock_driver);
}
module_exit(omap_hwspinlock_exit);

MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("Hardware spinlock driver for OMAP");
MODULE_AUTHOR("Simon Que <sque@ti.com>");
MODULE_AUTHOR("Hari Kanigeri <h-kanigeri2@ti.com>");
MODULE_AUTHOR("Ohad Ben-Cohen <ohad@wizery.com>");
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