Revision dc280d93623927570da279e99393879dbbab39e7 authored by Thomas Gleixner on 21 December 2016, 19:19:49 UTC, committed by Thomas Gleixner on 25 December 2016, 09:47:42 UTC
Developers manage to overwrite states blindly without thought. That's fatal
and hard to debug. Add sanity checks to make it fail.

This requries to restructure the code so that the dynamic state allocation
happens in the same lock protected section as the actual store. Otherwise
the previous assignment of 'Reserved' to the name field would trigger the
overwrite check.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Link: http://lkml.kernel.org/r/20161221192111.675234535@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 parent 59fefd0
Raw File
intel_soc_pmic_core.c
/*
 * intel_soc_pmic_core.c - Intel SoC PMIC MFD Driver
 *
 * Copyright (C) 2013, 2014 Intel Corporation. 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 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.
 *
 * Author: Yang, Bin <bin.yang@intel.com>
 * Author: Zhu, Lejun <lejun.zhu@linux.intel.com>
 */

#include <linux/module.h>
#include <linux/mfd/core.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/gpio/consumer.h>
#include <linux/acpi.h>
#include <linux/regmap.h>
#include <linux/mfd/intel_soc_pmic.h>
#include <linux/gpio/machine.h>
#include <linux/pwm.h>
#include "intel_soc_pmic_core.h"

/* Lookup table for the Panel Enable/Disable line as GPIO signals */
static struct gpiod_lookup_table panel_gpio_table = {
	/* Intel GFX is consumer */
	.dev_id = "0000:00:02.0",
	.table = {
		/* Panel EN/DISABLE */
		GPIO_LOOKUP("gpio_crystalcove", 94, "panel", GPIO_ACTIVE_HIGH),
		{ },
	},
};

/* PWM consumed by the Intel GFX */
static struct pwm_lookup crc_pwm_lookup[] = {
	PWM_LOOKUP("crystal_cove_pwm", 0, "0000:00:02.0", "pwm_backlight", 0, PWM_POLARITY_NORMAL),
};

static int intel_soc_pmic_find_gpio_irq(struct device *dev)
{
	struct gpio_desc *desc;
	int irq;

	desc = devm_gpiod_get_index(dev, "intel_soc_pmic", 0, GPIOD_IN);
	if (IS_ERR(desc))
		return PTR_ERR(desc);

	irq = gpiod_to_irq(desc);
	if (irq < 0)
		dev_warn(dev, "Can't get irq: %d\n", irq);

	return irq;
}

static int intel_soc_pmic_i2c_probe(struct i2c_client *i2c,
				    const struct i2c_device_id *i2c_id)
{
	struct device *dev = &i2c->dev;
	const struct acpi_device_id *id;
	struct intel_soc_pmic_config *config;
	struct intel_soc_pmic *pmic;
	int ret;
	int irq;

	id = acpi_match_device(dev->driver->acpi_match_table, dev);
	if (!id || !id->driver_data)
		return -ENODEV;

	config = (struct intel_soc_pmic_config *)id->driver_data;

	pmic = devm_kzalloc(dev, sizeof(*pmic), GFP_KERNEL);
	if (!pmic)
		return -ENOMEM;

	dev_set_drvdata(dev, pmic);

	pmic->regmap = devm_regmap_init_i2c(i2c, config->regmap_config);

	/*
	 * On some boards the PMIC interrupt may come from a GPIO line. Try to
	 * lookup the ACPI table for a such connection and setup a GPIO
	 * interrupt if it exists. Otherwise use the IRQ provided by I2C
	 */
	irq = intel_soc_pmic_find_gpio_irq(dev);
	pmic->irq = (irq < 0) ? i2c->irq : irq;

	ret = regmap_add_irq_chip(pmic->regmap, pmic->irq,
				  config->irq_flags | IRQF_ONESHOT,
				  0, config->irq_chip,
				  &pmic->irq_chip_data);
	if (ret)
		return ret;

	ret = enable_irq_wake(pmic->irq);
	if (ret)
		dev_warn(dev, "Can't enable IRQ as wake source: %d\n", ret);

	/* Add lookup table binding for Panel Control to the GPIO Chip */
	gpiod_add_lookup_table(&panel_gpio_table);

	/* Add lookup table for crc-pwm */
	pwm_add_table(crc_pwm_lookup, ARRAY_SIZE(crc_pwm_lookup));

	ret = mfd_add_devices(dev, -1, config->cell_dev,
			      config->n_cell_devs, NULL, 0,
			      regmap_irq_get_domain(pmic->irq_chip_data));
	if (ret)
		goto err_del_irq_chip;

	return 0;

err_del_irq_chip:
	regmap_del_irq_chip(pmic->irq, pmic->irq_chip_data);
	return ret;
}

static int intel_soc_pmic_i2c_remove(struct i2c_client *i2c)
{
	struct intel_soc_pmic *pmic = dev_get_drvdata(&i2c->dev);

	regmap_del_irq_chip(pmic->irq, pmic->irq_chip_data);

	/* Remove lookup table for Panel Control from the GPIO Chip */
	gpiod_remove_lookup_table(&panel_gpio_table);

	/* remove crc-pwm lookup table */
	pwm_remove_table(crc_pwm_lookup, ARRAY_SIZE(crc_pwm_lookup));

	mfd_remove_devices(&i2c->dev);

	return 0;
}

static void intel_soc_pmic_shutdown(struct i2c_client *i2c)
{
	struct intel_soc_pmic *pmic = dev_get_drvdata(&i2c->dev);

	disable_irq(pmic->irq);

	return;
}

#if defined(CONFIG_PM_SLEEP)
static int intel_soc_pmic_suspend(struct device *dev)
{
	struct intel_soc_pmic *pmic = dev_get_drvdata(dev);

	disable_irq(pmic->irq);

	return 0;
}

static int intel_soc_pmic_resume(struct device *dev)
{
	struct intel_soc_pmic *pmic = dev_get_drvdata(dev);

	enable_irq(pmic->irq);

	return 0;
}
#endif

static SIMPLE_DEV_PM_OPS(intel_soc_pmic_pm_ops, intel_soc_pmic_suspend,
			 intel_soc_pmic_resume);

static const struct i2c_device_id intel_soc_pmic_i2c_id[] = {
	{ }
};
MODULE_DEVICE_TABLE(i2c, intel_soc_pmic_i2c_id);

#if defined(CONFIG_ACPI)
static const struct acpi_device_id intel_soc_pmic_acpi_match[] = {
	{"INT33FD", (kernel_ulong_t)&intel_soc_pmic_config_crc},
	{ },
};
MODULE_DEVICE_TABLE(acpi, intel_soc_pmic_acpi_match);
#endif

static struct i2c_driver intel_soc_pmic_i2c_driver = {
	.driver = {
		.name = "intel_soc_pmic_i2c",
		.pm = &intel_soc_pmic_pm_ops,
		.acpi_match_table = ACPI_PTR(intel_soc_pmic_acpi_match),
	},
	.probe = intel_soc_pmic_i2c_probe,
	.remove = intel_soc_pmic_i2c_remove,
	.id_table = intel_soc_pmic_i2c_id,
	.shutdown = intel_soc_pmic_shutdown,
};

module_i2c_driver(intel_soc_pmic_i2c_driver);

MODULE_DESCRIPTION("I2C driver for Intel SoC PMIC");
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Yang, Bin <bin.yang@intel.com>");
MODULE_AUTHOR("Zhu, Lejun <lejun.zhu@linux.intel.com>");
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