sysfs方式实现马达驱动
由于对sysfs的概念不是太清楚，只是知道sysfs是一种类似于/proc的虚拟文件系统，可以在用户空间读写sysfs中的相应文件访问或控制内核空间数据，后拜读各类文章后终于对sysfs及平台设备有了更深层次的理解，但读的再多不如亲手一试。恰巧公司需要为android系统提供一个马达驱动，并且android又恰巧很多驱动的读写方式都是通过sysfs操作的，于是开始行动……
#define VIBRA_MINOR 88
#define STARTUP_VIBRA_DELAY 150
static unsigned int onkey_stat;
static struct timer_list vibra_timer;
static void vibra_stop_vibration(unsigned long data)
{
struct micco_vibra *vibra = (void *)data;
struct vibra_control *control = vibra->vibra_ctl;
control->level = 0x0;
micco_write(MICCO_VIBRA_CONTROL, control->level);
}
static int raw_vibrate(int level) //驱动马达，level控制转速
{
u8 val;
val = level & 0x00fe;
DMSG("+/-vibra_ioctl/n");
micco_write(MICCO_VIBRA_CONTROL, val);
return 0;
}
static int adv_vibrate(struct vibra_control *ctl) //驱动马达，level控制转速
{
u8 val;
val = ctl->level & 0x00fe;
micco_write(MICCO_VIBRA_CONTROL, val);
mod_timer(&vibra_timer, jiffies + msecs_to_jiffies(ctl->m_time));
return 0;
}
static int vibra_ioctl(struct inode *inode, struct file *file,
unsigned int cmd, unsigned long arg) //用户空间通过ioctl操作马达
{
int ret;
unsigned int level;
u8 val;
unsigned int onkey_val;
struct vibra_control ctl;
switch(cmd) {
case VIBRA_RAW_VIBTATION:
ret = copy_from_user(&level, (void *)arg, sizeof(unsigned int));
ret = raw_vibrate(level);
break;
case VIBRA_ADV_VIBTATION:
ret = copy_from_user(&ctl, (void *)arg, sizeof(struct vibra_control));
ret = adv_vibrate(&ctl);
break;
case VIBRA_POWERON_STAT_GET:
ret = copy_to_user((void *)arg, &onkey_stat, sizeof(unsigned int));
break;
case VIBRA_ONKEY_STAT_GET:
ret = micco_read(MICCO_STATUS_A, &val);
if (ret < 0) {
printk("read MICCO_STATUS_A failed/n");
onkey_val = 0;
}
onkey_val = !(val & MICCO_STATUS_A_ONKEY);
ret = copy_to_user((void *)arg, &onkey_val, sizeof(unsigned int));
break;
default:
if (cmd < 0xFF)
ret = raw_vibrate(cmd);
else
ret = -ENOIOCTLCMD;
}
return ret;
}
/*用户空间读取马达运转时间*/
static ssize_t vibrator_mtime_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct micco_vibra *vibra = dev_get_drvdata(dev);
struct vibra_control *control = vibra->vibra_ctl;
return sprintf(buf, "%u/n", control->m_time);
}
/*用户空间修改马达运转时间*/
static ssize_t vibrator_mtime_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct micco_vibra *vibra = dev_get_drvdata(dev);
struct vibra_control *control = vibra->vibra_ctl;
char *endp;
control->m_time = simple_strtoul(buf, &endp, 10);
DMSG("vibrator_mtime_store: m_tme = %d/n",control->m_time );
adv_vibrate(control);
return count;
}
/*属性设置及读写属性注册*/
static DEVICE_ATTR(mtime, 0664, vibrator_mtime_show,
vibrator_mtime_store);
/*用户空间读马达转速*/
static ssize_t vibrator_level_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct micco_vibra *vibra = dev_get_drvdata(dev);
struct vibra_control *control = vibra->vibra_ctl;
return sprintf(buf, "%u/n", control->level);
}
/*用户空间调整马达转速*/
static ssize_t vibrator_level_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct micco_vibra *vibra = dev_get_drvdata(dev);
struct vibra_control *control = vibra->vibra_ctl;
char *endp;
control->level = simple_strtoul(buf, &endp, 10);
DMSG("vibrator_level_store:raw_vibrate(%x)", control->level);
adv_vibrate(control);
return count;
}
/*属性设置及读写属性注册*/
static DEVICE_ATTR(level, 0664, vibrator_level_show,
vibrator_level_store);
static struct file_operations vibra_fops = {
.owner = THIS_MODULE,
.ioctl = vibra_ioctl,
};
static struct miscdevice vibra_miscdev = {
.minor = VIBRA_MINOR,
.name = "micco_vibra",
.fops = &vibra_fops,
};
static int __devinit vibra_init(struct micco_vibra *vibra)
{
struct vibra_control *ctl;
int ret;
u8 val;
ctl = kzalloc(sizeof(*ctl), GFP_KERNEL);
if (ctl == NULL)
return -ENOMEM;
vibra->vibra_ctl = ctl;
ctl->level=0;
ctl->m_time=0;
vibra_timer.function = vibra_stop_vibration;
vibra_timer.data = (unsigned long) vibra;
init_timer(&vibra_timer);
/*注册vibra_miscdev设备*/
ret = misc_register(&vibra_miscdev);
if (ret < 0) {
dev_err(&vibra->pdev->dev, "can't register vibra device/n");
goto err2;
}
printk("/nVIBRA Probe vibra_miscdev->minor=%d/n",vibra_miscdev.minor);
ret = micco_read(MICCO_FAULT_LOG, &val);
printk("Fault Log value is 0x%x---------->/n", val);
ret = micco_read(MICCO_STATUS_A, &val);
if (ret < 0) {
printk("read MICCO_STATUS_A failed/n");
onkey_stat = 0;
return 0;
}
onkey_stat = !(val & MICCO_STATUS_A_ONKEY);
if (onkey_stat) {
raw_vibrate(0x7e);
mdelay(100);
raw_vibrate(0x0);
}
/*创建sysfs文件系统节点*/
if (device_create_file(&vibra->pdev->dev, &dev_attr_level) < 0)
goto err3;
if (device_create_file(&vibra->pdev->dev, &dev_attr_mtime) < 0)
goto err4;
return 0;
/*
err5:
device_remove_file(&vibra->pdev->dev, &dev_attr_vibrator_mtime);
*/
err4:
device_remove_file(&vibra->pdev->dev, &dev_attr_level);
err3:
misc_deregister(&vibra_miscdev);
err2:
kfree(ctl);
return ret;
}
static void __devexit vibra_exit(struct micco_vibra *vibra)
{
device_remove_file(&vibra->pdev->dev, &dev_attr_mtime);
device_remove_file(&vibra->pdev->dev, &dev_attr_level);
misc_deregister(&vibra_miscdev);
}
/****************************************************************************
* Initialization / Registeration / Removal
***************************************************************************/
static int vibra_probe(struct platform_device *pdev)
{
struct micco_vibra *vibra;
int r = -ENODEV;
vibra = kzalloc(sizeof(*vibra), GFP_KERNEL);
if (vibra == NULL)
return -ENOMEM;
/*注册驱动数据 */
dev_set_drvdata(&pdev->dev, vibra);
vibra->pdev = pdev;
r = vibra_init(vibra);
if (r)
goto err1;
return 0;
err1:
kfree(vibra);
return r;
}
static int vibra_remove(struct platform_device *pdev)
{
struct micco_vibra *vibra = dev_get_drvdata(&pdev->dev);
dev_dbg(&vibra->pdev->dev, "%s/n", __FUNCTION__);
vibra_exit(vibra);
kfree(vibra);
return 0;
}
static struct platform_device vibra_plat_device = {
.name = "micco-vibra", //sysfs设备目录“/sys/devices/platform/micco-vibra.0”
.id = 0,
};
static struct platform_driver vibra_plat_driver = {
.driver = {
.name = "micco-vibra", //和vibra_plat_device 的name名字相同
.owner = THIS_MODULE,
},
.probe = vibra_probe,
.remove = vibra_remove,
};
static int __init plat_vibra_init(void)
{
int rc;
printk("vibra driver initializing/n");
rc = platform_device_register(&vibra_plat_device);
if (rc < 0)
return rc;
rc = platform_driver_register(&vibra_plat_driver);
if (rc < 0)
goto err_register_vibra_dev;
return rc;
err_register_vibra_dev:
platform_device_unregister (&vibra_plat_device);
return rc;
}
static void __exit plat_vibra_exit(void)
{
platform_driver_unregister(&vibra_plat_driver);
platform_device_unregister (&vibra_plat_device);
}
module_init(plat_vibra_init);
module_exit(plat_vibra_exit);
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