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分类: LINUX

2011-05-20 07:13:31


mma845x.c:

#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/i2c.h>
#include <linux/pm.h>
#include <linux/mutex.h>
#include <linux/delay.h>
#include <linux/hwmon-sysfs.h>
#include <linux/hwmon.h>
#include <linux/input-polldev.h>

#define MMA8450_ID        0xc6
#define MMA8451_ID        0x1a
#define MMA8452_ID        0x2a
#define MMA8453_ID        0x3a

#define POLL_INTERVAL_MIN    1
#define POLL_INTERVAL_MAX    500
#define POLL_INTERVAL        100 /* msecs */
#define INPUT_FUZZ        32
#define INPUT_FLAT        32
#define MODE_CHANGE_DELAY_MS    100

#define MMA845X_STATUS_ZYXDR    0x08
#define MMA845X_BUF_SIZE    6

/* mma8451 registers */
enum mma8451_registers {
    MMA8451_STATUS = 0x00,
    MMA8451_OUT_X_MSB,
    MMA8451_OUT_X_LSB,
    MMA8451_OUT_Y_MSB,
    MMA8451_OUT_Y_LSB,
    MMA8451_OUT_Z_MSB,
    MMA8451_OUT_Z_LSB,
    MMA8451_F_SETUP = 0x09,
    MMA8451_TRIG_CFG,
    MMA8451_SYSMOD,
    MMA8451_INT_SOURCE,
    MMA8451_WHO_AM_I,
    MMA8451_XYZ_DATA_CFG,
    MMA8451_HP_FILTER_CUTOFF,
    MMA8451_PL_STATUS,
    MMA8451_PL_CFG,
    MMA8451_PL_COUNT,
    MMA8451_PL_BF_ZCOMP,
    MMA8451_P_L_THS_REG,
    MMA8451_FF_MT_CFG,
    MMA8451_FF_MT_SRC,
    MMA8451_FF_MT_THS,
    MMA8451_FF_MT_COUNT,
    MMA8451_TRANSIENT_CFG = 0x1D,
    MMA8451_TRANSIENT_SRC,
    MMA8451_TRANSIENT_THS,
    MMA8451_TRANSIENT_COUNT,
    MMA8451_PULSE_CFG,
    MMA8451_PULSE_SRC,
    MMA8451_PULSE_THSX,
    MMA8451_PULSE_THSY,
    MMA8451_PULSE_THSZ,
    MMA8451_PULSE_TMLT,
    MMA8451_PULSE_LTCY,
    MMA8451_PULSE_WIND,
    MMA8451_ASLP_COUNT,
    MMA8451_CTRL_REG1,
    MMA8451_CTRL_REG2,
    MMA8451_CTRL_REG3,
    MMA8451_CTRL_REG4,
    MMA8451_CTRL_REG5,
    MMA8451_OFF_X,
    MMA8451_OFF_Y,
    MMA8451_OFF_Z,
    MMA8451_REG_END,
};

/* mma8450 registers */
enum mma8450_registers {
    MMA8450_STATUS1 = 0x00,
    MMA8450_OUT_X8,
    MMA8450_OUT_Y8,
    MMA8450_OUT_Z8,
    MMA8450_STATUS2,
    MMA8450_OUT_X_LSB,
    MMA8450_OUT_X_MSB,
    MMA8450_OUT_Y_LSB,
    MMA8450_OUT_Y_MSB,
    MMA8450_OUT_Z_LSB,
    MMA8450_OUT_Z_MSB,
    MMA8450_STATUS3,
    MMA8450_OUT_X_DELTA,
    MMA8450_OUT_Y_DELTA,
    MMA8450_OUT_Z_DELTA,
    MMA8450_WHO_AM_I,
    MMA8450_F_STATUS,
    MMA8450_F_8DATA,
    MMA8450_F_12DATA,
    MMA8450_F_SETUP,
    MMA8450_SYSMOD,
    MMA8450_INT_SOURCE,
    MMA8450_XYZ_DATA_CFG,
    MMA8450_HP_FILTER_CUTOFF,
    MMA8450_PL_STATUS,
    MMA8450_PL_PRE_STATUS,
    MMA8450_PL_CFG,
    MMA8450_PL_COUNT,
    MMA8450_PL_BF_ZCOMP,
    MMA8450_PL_P_L_THS_REG1,
    MMA8450_PL_P_L_THS_REG2,
    MMA8450_PL_P_L_THS_REG3,
    MMA8450_PL_L_P_THS_REG1,
    MMA8450_PL_L_P_THS_REG2,
    MMA8450_PL_L_P_THS_REG3,
    MMA8450_FF_MT_CFG_1,
    MMA8450_FF_MT_SRC_1,
    MMA8450_FF_MT_THS_1,
    MMA8450_FF_MT_COUNT_1,
    MMA8450_FF_MT_CFG_2,
    MMA8450_FF_MT_SRC_2,
    MMA8450_FF_MT_THS_2,
    MMA8450_FF_MT_COUNT_2,
    MMA8450_TRANSIENT_CFG,
    MMA8450_TRANSIENT_SRC,
    MMA8450_TRANSIENT_THS,
    MMA8450_TRANSIENT_COUNT,
    MMA8450_PULSE_CFG,
    MMA8450_PULSE_SRC,
    MMA8450_PULSE_THSX,
    MMA8450_PULSE_THSY,
    MMA8450_PULSE_THSZ,
    MMA8450_PULSE_TMLT,
    MMA8450_PULSE_LTCY,
    MMA8450_PULSE_WIND,
    MMA8450_ASLP_COUNT,
    MMA8450_CTRL_REG1,
    MMA8450_CTRL_REG2,
    MMA8450_CTRL_REG3,
    MMA8450_CTRL_REG4,
    MMA8450_CTRL_REG5,
    MMA8450_OFF_X,
    MMA8450_OFF_Y,
    MMA8450_OFF_Z,
    MMA8450_REG_END,
};


/* MMA845x have 3 different mode, each mode have different sensitivity
 * as below */

/* MODE_2G: sensitivity is 1024 counts/g
 * MODE_4G: sensitivity is 512 counts/g
 * MODE_8G: sensitivity is 256 counts/g
 */

enum mma845x_mode {
    MODE_2G = 0,
    MODE_4G,
    MODE_8G,
};

enum mma845x_type {
    MMA8450,
    MMA8451,
    MMA8452,
    MMA8453,
};

struct mma845x_info {
    int type;
    u8 mode;
    u8 ctl_reg;
    struct i2c_client *client;
    struct input_polled_dev *idev;
    struct device *hwmon_dev;
};

static DEFINE_MUTEX(mma845x_lock);

/* Default use 2G mode */
#define DEFAULT_SENSTIVE_MODE MODE_2G

static const char *get_mma845x_name(int type)
{
    switch (type) {
    case MMA8450:
        return "mma8450";
    case MMA8451:
        return "mma8451";
    case MMA8452:
        return "mma8452";
    case MMA8453:
        return "mma8453";
    default:
        return "unknown";
    }
}

static int get_ctrl_register(int type)
{
    switch (type) {
    case MMA8450:
        return MMA8450_STATUS3;
    case MMA8451:
        return MMA8451_STATUS;
    }
    return -EINVAL;
}

static int mma8450_change_mode(struct mma845x_info *priv)
{
    int ret;
    ret = i2c_smbus_write_byte_data(priv->client,
                    MMA8450_XYZ_DATA_CFG, 0x07);
    ret |= i2c_smbus_write_byte_data(priv->client,
                     MMA8450_CTRL_REG1, priv->mode + 1);
    if (ret < 0) {
        dev_err(&priv->client->dev, "mma8450 init error");
        goto out;
    }
    mdelay(MODE_CHANGE_DELAY_MS);
    return 0;
out:
    return ret;
}

static int mma8451_change_mode(struct mma845x_info *priv)
{
    int ret;
    priv->ctl_reg |= 0x01;
    ret = i2c_smbus_write_byte_data(priv->client, MMA8451_CTRL_REG1, 0);
    if (ret < 0)
        goto out;
    ret = i2c_smbus_write_byte_data(priv->client,
                    MMA8451_XYZ_DATA_CFG, priv->mode);
    ret |= i2c_smbus_write_byte_data(priv->client,
                     MMA8451_CTRL_REG1, priv->ctl_reg);
    if (ret < 0) {
        dev_err(&priv->client->dev, "mma8451 init error");
        goto out;
    }

    mdelay(MODE_CHANGE_DELAY_MS);
    return 0;
out:
    return ret;
}

static int init_mma845x_chip(struct mma845x_info *priv)
{
    int ret;

    switch (priv->type) {
    case MMA8450:
        ret = mma8450_change_mode(priv);
        break;
    case MMA8451:
        ret = mma8451_change_mode(priv);
        break;
    default:
        dev_err(&priv->client->dev, "sensor %s"
            "is not supported by mma845x driver",
            get_mma845x_name(priv->type));
        ret = -EINVAL;
    }
    return ret;
}

static int mma845x_read_data(struct mma845x_info *priv, short *x,
             short *y, short *z)
{
    u8 buf[MMA845X_BUF_SIZE];
    int reg_addr = -1;
    int ret;

    switch (priv->type) {
    case MMA8450:
        reg_addr = MMA8450_OUT_X_LSB;
        break;
    case MMA8451:
        reg_addr = MMA8451_OUT_X_MSB;
        break;
    default:
        break;
    }

    ret = i2c_smbus_read_i2c_block_data(priv->client, reg_addr,
                     MMA845X_BUF_SIZE, buf);
    if (ret < MMA845X_BUF_SIZE) {
        dev_err(&priv->client->dev, "i2c block read failed\n");
        return -EIO;
    }

    switch (priv->type) {
    case MMA8450:
        *x = (buf[1] << 8) | ((buf[0] << 4) & 0xf0);
        *y = (buf[3] << 8) | ((buf[2] << 4) & 0xf0);
        *z = (buf[5] << 8) | ((buf[4] << 4) & 0xf0);
        *x >>= 4;
        *y >>= 4;
        *z >>= 4;
        break;
    case MMA8451:
        *x = (buf[0] << 8) | buf[1];
        *y = (buf[2] << 8) | buf[3];
        *z = (buf[4] << 8) | buf[5];
        *x >>= 2;
        *y >>= 2;
        *z >>= 2;
        break;
    }

    if (priv->mode == MODE_4G) {
        *x <<= 1;
        *y <<= 1;
        *z <<= 1;
    } else if (priv->mode == MODE_8G) {
        *x <<= 2;
        *y <<= 2;
        *z <<= 2;
    }

    return 0;
}

static void mma845x_dev_poll(struct input_polled_dev *dev)
{
    struct mma845x_info *priv = dev->private;

    short x = -1, y = -1, z = -1;
    int ret;
    int reg_addr;

    mutex_lock(&mma845x_lock);

    reg_addr = get_ctrl_register(priv->type);

    do
        ret = i2c_smbus_read_byte_data(priv->client, reg_addr);
    while (!(ret & MMA845X_STATUS_ZYXDR));

    ret = mma845x_read_data(priv, &x, &y, &z);
    if (!ret) {
        input_report_abs(priv->idev->input, ABS_X, x);
        input_report_abs(priv->idev->input, ABS_Y, y);
        input_report_abs(priv->idev->input, ABS_Z, z);
        input_sync(priv->idev->input);
    }

    mutex_unlock(&mma845x_lock);
}

/*
 * detecting which chip is on board. mma845x are have same i2c address,
 * it's impossible exists multiple instance on same board.
 */

static int get_device_type(struct i2c_client *client)
{
    int ret;
    /* high 2-bits of MMA8450_WHO_AM_I(0x0f) register on
     * mma8451[2,3] will always zero, but MMA8450 Chip-ID's high
     * 2-bits not zero */

    ret = i2c_smbus_read_byte_data(client, MMA8450_WHO_AM_I);
    if (ret == MMA8450_ID)
        return MMA8450;
    ret = i2c_smbus_read_byte_data(client, MMA8451_WHO_AM_I);
    switch (ret) {
    case MMA8451_ID:
        return MMA8451;
    case MMA8452_ID:
        return MMA8452;
    case MMA8453_ID:
        return MMA8453;
    default:
        return -EINVAL;
    }
}

static int __devinit mma845x_probe(struct i2c_client *client,
                 const struct i2c_device_id *id)
{
    int ret;
    struct input_dev *input_idev;
    struct i2c_adapter *adapter;
    struct mma845x_info *priv;

    adapter = to_i2c_adapter(client->dev.parent);
    ret = i2c_check_functionality(adapter,
                     I2C_FUNC_SMBUS_BYTE |
                     I2C_FUNC_SMBUS_BYTE_DATA);
    if (!ret)
        goto err_out;

    priv = kzalloc(sizeof(struct mma845x_info), GFP_KERNEL);
    if (!priv) {
        dev_err(&client->dev, "failed to alloc driver info\n");
        goto err_out;
    }

    ret = get_device_type(client);
    if (ret < 0)
        goto err_out;

    priv->type = ret;
    priv->client = client;
    priv->mode = DEFAULT_SENSTIVE_MODE;

    dev_dbg(&client->dev, "found %s model accelerator\n",
         get_mma845x_name(priv->type));

    ret = init_mma845x_chip(priv);

    if (ret) {
        dev_err(&client->dev,
            "error when init %s chip:(%d)\n",
            get_mma845x_name(priv->type), ret);
        goto err_alloc_priv;
    }

    priv->hwmon_dev = hwmon_device_register(&client->dev);
    if (!priv->hwmon_dev) {
        ret = -ENOMEM;
        dev_err(&client->dev,
            "error register hwmon device\n");
        goto err_alloc_priv;
    }

    priv->idev = input_allocate_polled_device();
    if (!priv->idev) {
        ret = -ENOMEM;
        dev_err(&client->dev, "alloc poll device failed!\n");
        goto err_alloc_poll_device;
    }
    priv->idev->private = priv;
    priv->idev->poll = mma845x_dev_poll;
    priv->idev->poll_interval = POLL_INTERVAL;
    priv->idev->poll_interval_min = POLL_INTERVAL_MIN;
    priv->idev->poll_interval_max = POLL_INTERVAL_MAX;

    input_idev = priv->idev->input;
    input_idev->name = get_mma845x_name(priv->type);
    input_idev->id.bustype = BUS_I2C;
    input_idev->evbit[0] = BIT_MASK(EV_ABS);

    input_set_abs_params(input_idev, ABS_X, -8192, 8191,
             INPUT_FUZZ, INPUT_FLAT);
    input_set_abs_params(input_idev, ABS_Y, -8192, 8191,
             INPUT_FUZZ, INPUT_FLAT);
    input_set_abs_params(input_idev, ABS_Z, -8192, 8191,
             INPUT_FUZZ, INPUT_FLAT);

    ret = input_register_polled_device(priv->idev);
    if (ret) {
        dev_err(&client->dev, "register poll device failed!\n");
        goto err_register_polled_device;
    }

    i2c_set_clientdata(client, priv);
    dev_dbg(&client->dev, "%s accelerator init success\n",
        get_mma845x_name(priv->type));

    return 0;
err_register_polled_device:
    input_free_polled_device(priv->idev);
err_alloc_poll_device:
    hwmon_device_unregister(&client->dev);
err_alloc_priv:
    kfree(priv);
err_out:
    return ret;
}

static int mma845x_stop_chip(struct i2c_client *client)
{
    struct mma845x_info *priv = i2c_get_clientdata(client);
    int ret;
    switch (priv->type) {
    case MMA8450:
        priv->ctl_reg = i2c_smbus_read_byte_data(client,
                             MMA8450_CTRL_REG1);
        ret = i2c_smbus_write_byte_data(client, MMA8450_CTRL_REG1,
                        priv->ctl_reg & 0xFC);
        break;
    case MMA8451:
        priv->ctl_reg = i2c_smbus_read_byte_data(client,
                             MMA8451_CTRL_REG1);
        ret = i2c_smbus_write_byte_data(client, MMA8451_CTRL_REG1,
                        priv->ctl_reg & 0xFE);
        break;
    default:
        ret = -EINVAL;
    }
    return ret;
}

static int __devexit mma845x_remove(struct i2c_client *client)
{
    int ret;
    struct mma845x_info *priv = i2c_get_clientdata(client);
    ret = mma845x_stop_chip(client);
    input_free_polled_device(priv->idev);
    hwmon_device_unregister(priv->hwmon_dev);

    return ret;
}

#ifdef CONFIG_PM_SLEEP
static int mma845x_suspend(struct device *dev)
{
    struct i2c_client *client = to_i2c_client(dev);

    return mma845x_stop_chip(client);
}

static int mma845x_resume(struct device *dev)
{
    struct i2c_client *client = to_i2c_client(dev);
    struct mma845x_info *priv = i2c_get_clientdata(client);

    return init_mma845x_chip(priv);
}
#endif

static const struct i2c_device_id mma845x_id[] = {
    {"mma8451", 0},
    {"mma8450", 0},
    {},
};
MODULE_DEVICE_TABLE(i2c, mma845x_id);

static SIMPLE_DEV_PM_OPS(mma845x_pm_ops, mma845x_suspend, mma845x_resume);
static struct i2c_driver mma845x_driver = {
    .driver = {
         .name = "mma845x",
         .owner = THIS_MODULE,
         .pm = &mma845x_pm_ops,
         },
    .probe = mma845x_probe,
    .remove = __devexit_p(mma845x_remove),
    .id_table = mma845x_id,
};

static int __init mma845x_init(void)
{
    return i2c_add_driver(&mma845x_driver);
}

static void __exit mma845x_exit(void)
{
    i2c_del_driver(&mma845x_driver);
}

module_init(mma845x_init);
module_exit(mma845x_exit);

MODULE_AUTHOR("Zhang Jiejing ");
MODULE_DESCRIPTION("Freescale MMA845x 3-axis gravity accelerator sensors");
MODULE_LICENSE("GPL");


Makefile:

obj-$(CONFIG_SENSORS_MMA845X) += mma845x.o


Kconfig:

config SENSORS_MMA845X 

 tristate "Freescale MMA845X sensor chips" 

 depends on I2C 

 help If you say yes here you get support for the Freescale MMA8450/MMA8451 gravity accelerator sensors chips. This driver can also be build as a module. If so, the module will be called mma845x.


shell:

CONFIG_SENSORS_MMA845X=m make -C /lib/modules/`uname -r`/build/ M=`pwd` modules

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