1. 根目录:
2. drivers
3. misc
4. lis3lv02d
5. lis3lv02d_i2c.c

/*
 * drivers/hwmon/lis3lv02d_i2c.c
 *
 * Implements I2C interface for lis3lv02d (STMicroelectronics) accelerometer.
 * Driver is based on corresponding SPI driver written by Daniel Mack
 * (lis3lv02d_spi.c (C) 2009 Daniel Mack <daniel@caiaq.de> ).
 *
 * Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
 *
 * Contact: Samu Onkalo <samu.p.onkalo@nokia.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.
 *
 * 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., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/pm_runtime.h>
#include <linux/delay.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/of_device.h>

#include "lis3lv02d.h"

#define DRV_NAME	"lis3lv02d_i2c"

static const char reg_vdd[]    = "Vdd";
static const char reg_vdd_io[] = "Vdd_IO";

static int lis3_reg_ctrl(struct lis3lv02d *lis3, bool state)
{
	int ret;
	if (state == LIS3_REG_OFF) {
		ret = regulator_bulk_disable(ARRAY_SIZE(lis3->regulators),
					lis3->regulators);
	} else {
		ret = regulator_bulk_enable(ARRAY_SIZE(lis3->regulators),
					lis3->regulators);
		/* Chip needs time to wakeup. Not mentioned in datasheet */
		usleep_range(10000, 20000);
	}
	return ret;
}

static inline s32 lis3_i2c_write(struct lis3lv02d *lis3, int reg, u8 value)
{
	struct i2c_client *c = lis3->bus_priv;
	return i2c_smbus_write_byte_data(c, reg, value);
}

static inline s32 lis3_i2c_read(struct lis3lv02d *lis3, int reg, u8 *v)
{
	struct i2c_client *c = lis3->bus_priv;
	*v = i2c_smbus_read_byte_data(c, reg);
	return 0;
}

static inline s32 lis3_i2c_blockread(struct lis3lv02d *lis3, int reg, int len,
				u8 *v)
{
	struct i2c_client *c = lis3->bus_priv;
	reg |= (1 << 7); /* 7th bit enables address auto incrementation */
	return i2c_smbus_read_i2c_block_data(c, reg, len, v);
}

static int lis3_i2c_init(struct lis3lv02d *lis3)
{
	u8 reg;
	int ret;

	lis3_reg_ctrl(lis3, LIS3_REG_ON);

	lis3->read(lis3, WHO_AM_I, &reg);
	if (reg != lis3->whoami)
		printk(KERN_ERR "lis3: power on failure\n");

	/* power up the device */
	ret = lis3->read(lis3, CTRL_REG1, &reg);
	if (ret < 0)
		return ret;

	if (lis3->whoami == WAI_3DLH)
		reg |= CTRL1_PM0 | CTRL1_Xen | CTRL1_Yen | CTRL1_Zen;
	else
		reg |= CTRL1_PD0 | CTRL1_Xen | CTRL1_Yen | CTRL1_Zen;

	return lis3->write(lis3, CTRL_REG1, reg);
}

/* Default axis mapping but it can be overwritten by platform data */
static union axis_conversion lis3lv02d_axis_map =
	{ .as_array = { LIS3_DEV_X, LIS3_DEV_Y, LIS3_DEV_Z } };

#ifdef CONFIG_OF
static struct of_device_id lis3lv02d_i2c_dt_ids[] = {
	{ .compatible = "st,lis3lv02d" },
	{}
};
MODULE_DEVICE_TABLE(of, lis3lv02d_i2c_dt_ids);
#endif

static int lis3lv02d_i2c_probe(struct i2c_client *client,
					const struct i2c_device_id *id)
{
	int ret = 0;
	struct lis3lv02d_platform_data *pdata = client->dev.platform_data;

#ifdef CONFIG_OF
	if (of_match_device(lis3lv02d_i2c_dt_ids, &client->dev)) {
		lis3_dev.of_node = client->dev.of_node;
		ret = lis3lv02d_init_dt(&lis3_dev);
		if (ret)
			return ret;
		pdata = lis3_dev.pdata;
	}
#endif

	if (pdata) {
		if ((pdata->driver_features & LIS3_USE_BLOCK_READ) &&
			(i2c_check_functionality(client->adapter,
						I2C_FUNC_SMBUS_I2C_BLOCK)))
			lis3_dev.blkread  = lis3_i2c_blockread;

		if (pdata->axis_x)
			lis3lv02d_axis_map.x = pdata->axis_x;

		if (pdata->axis_y)
			lis3lv02d_axis_map.y = pdata->axis_y;

		if (pdata->axis_z)
			lis3lv02d_axis_map.z = pdata->axis_z;

		if (pdata->setup_resources)
			ret = pdata->setup_resources();

		if (ret)
			goto fail;
	}

	lis3_dev.regulators[0].supply = reg_vdd;
	lis3_dev.regulators[1].supply = reg_vdd_io;
	ret = regulator_bulk_get(&client->dev,
				 ARRAY_SIZE(lis3_dev.regulators),
				 lis3_dev.regulators);
	if (ret < 0)
		goto fail;

	lis3_dev.pdata	  = pdata;
	lis3_dev.bus_priv = client;
	lis3_dev.init	  = lis3_i2c_init;
	lis3_dev.read	  = lis3_i2c_read;
	lis3_dev.write	  = lis3_i2c_write;
	lis3_dev.irq	  = client->irq;
	lis3_dev.ac	  = lis3lv02d_axis_map;
	lis3_dev.pm_dev	  = &client->dev;

	i2c_set_clientdata(client, &lis3_dev);

	/* Provide power over the init call */
	lis3_reg_ctrl(&lis3_dev, LIS3_REG_ON);

	ret = lis3lv02d_init_device(&lis3_dev);

	lis3_reg_ctrl(&lis3_dev, LIS3_REG_OFF);

	if (ret)
		goto fail2;
	return 0;

fail2:
	regulator_bulk_free(ARRAY_SIZE(lis3_dev.regulators),
				lis3_dev.regulators);
fail:
	if (pdata && pdata->release_resources)
		pdata->release_resources();
	return ret;
}

static int lis3lv02d_i2c_remove(struct i2c_client *client)
{
	struct lis3lv02d *lis3 = i2c_get_clientdata(client);
	struct lis3lv02d_platform_data *pdata = client->dev.platform_data;

	if (pdata && pdata->release_resources)
		pdata->release_resources();

	lis3lv02d_joystick_disable(lis3);
	lis3lv02d_remove_fs(&lis3_dev);

	regulator_bulk_free(ARRAY_SIZE(lis3->regulators),
			    lis3_dev.regulators);
	return 0;
}

#ifdef CONFIG_PM_SLEEP
static int lis3lv02d_i2c_suspend(struct device *dev)
{
	struct i2c_client *client = container_of(dev, struct i2c_client, dev);
	struct lis3lv02d *lis3 = i2c_get_clientdata(client);

	if (!lis3->pdata || !lis3->pdata->wakeup_flags)
		lis3lv02d_poweroff(lis3);
	return 0;
}

static int lis3lv02d_i2c_resume(struct device *dev)
{
	struct i2c_client *client = container_of(dev, struct i2c_client, dev);
	struct lis3lv02d *lis3 = i2c_get_clientdata(client);

	/*
	 * pm_runtime documentation says that devices should always
	 * be powered on at resume. Pm_runtime turns them off after system
	 * wide resume is complete.
	 */
	if (!lis3->pdata || !lis3->pdata->wakeup_flags ||
		pm_runtime_suspended(dev))
		lis3lv02d_poweron(lis3);

	return 0;
}
#endif /* CONFIG_PM_SLEEP */

#ifdef CONFIG_PM_RUNTIME
static int lis3_i2c_runtime_suspend(struct device *dev)
{
	struct i2c_client *client = container_of(dev, struct i2c_client, dev);
	struct lis3lv02d *lis3 = i2c_get_clientdata(client);

	lis3lv02d_poweroff(lis3);
	return 0;
}

static int lis3_i2c_runtime_resume(struct device *dev)
{
	struct i2c_client *client = container_of(dev, struct i2c_client, dev);
	struct lis3lv02d *lis3 = i2c_get_clientdata(client);

	lis3lv02d_poweron(lis3);
	return 0;
}
#endif /* CONFIG_PM_RUNTIME */

static const struct i2c_device_id lis3lv02d_id[] = {
	{"lis3lv02d", LIS3LV02D},
	{"lis331dlh", LIS331DLH},
	{}
};

MODULE_DEVICE_TABLE(i2c, lis3lv02d_id);

static const struct dev_pm_ops lis3_pm_ops = {
	SET_SYSTEM_SLEEP_PM_OPS(lis3lv02d_i2c_suspend,
				lis3lv02d_i2c_resume)
	SET_RUNTIME_PM_OPS(lis3_i2c_runtime_suspend,
			   lis3_i2c_runtime_resume,
			   NULL)
};

static struct i2c_driver lis3lv02d_i2c_driver = {
	.driver	 = {
		.name   = DRV_NAME,
		.owner  = THIS_MODULE,
		.pm     = &lis3_pm_ops,
		.of_match_table = of_match_ptr(lis3lv02d_i2c_dt_ids),
	},
	.probe	= lis3lv02d_i2c_probe,
	.remove	= lis3lv02d_i2c_remove,
	.id_table = lis3lv02d_id,
};

module_i2c_driver(lis3lv02d_i2c_driver);

MODULE_AUTHOR("Nokia Corporation");
MODULE_DESCRIPTION("lis3lv02d I2C interface");
MODULE_LICENSE("GPL");