linux驱动(四):platform
2024-01-10 06:10:43
? ? ? ? 本文主要探讨x210驱动的平台设备类型(platform)以及misc设备。
驱动模型
????????设备驱动模型：总线(bus type)、设备(device)和驱动(driver)
????????总线：虚拟总线用于挂接驱动驱动和设备
????????总线、设备、驱动关系：/sys/bus下的子目录对应不同总线,总线目录有设备、驱动目录和、总线属性文件
总线
struct bus_type {
?? ?const char?? ??? ?*name;
?? ?struct bus_attribute?? ?*bus_attrs;
?? ?struct device_attribute?? ?*dev_attrs;
?? ?struct driver_attribute?? ?*drv_attrs;
?? ?int (*match)(struct device *dev, struct device_driver *drv);
?? ?int (*uevent)(struct device *dev, struct kobj_uevent_env *env);
?? ?int (*probe)(struct device *dev);
?? ?int (*remove)(struct device *dev);
?? ?void (*shutdown)(struct device *dev);
?? ?int (*suspend)(struct device *dev, pm_message_t state);
?? ?int (*resume)(struct device *dev);
?? ?const struct dev_pm_ops *pm;
?? ?struct bus_type_private *p;
};? ? ? ? 总线属性?
struct bus_attribute {
?? ?struct attribute?? ?attr;
?? ?ssize_t (*show)(struct bus_type *bus, char *buf);
?? ?ssize_t (*store)(struct bus_type *bus, const char *buf, size_t count);
};? ? ? ? 设备属性?
struct device_attribute {
?? ?struct attribute?? ?attr;
?? ?ssize_t (*show)(struct device *dev, struct device_attribute *attr,
?? ??? ??? ?char *buf);
?? ?ssize_t (*store)(struct device *dev, struct device_attribute *attr,
?? ??? ??? ? const char *buf, size_t count);
};? ? ? ? ?驱动属性? ??
struct driver_attribute {
struct attribute attr;
ssize_t (*show)(struct device_driver *driver, char *buf);
ssize_t (*store)(struct device_driver *driver, const char *buf,
size_t count);
};? ? ? ? ?公共属性结构体(show(read)和store(write)方法)
struct attribute {
?? ?const char?? ??? ?*name;
?? ?struct module?? ??? ?*owner;
?? ?mode_t?? ??? ??? ?mode;
#ifdef CONFIG_DEBUG_LOCK_ALLOC
?? ?struct lock_class_key?? ?*key;
?? ?struct lock_class_key?? ?skey;
#endif
};? ? ? ? 总线示例
struct bus_type i2c_bus_type = {
? ? ? ? .name ? ? ? ? ? = "i2c",
? ? ? ? .match ? ? ? ? ?= i2c_device_match,
? ? ? ? .probe ? ? ? ? ?= i2c_device_probe,
? ? ? ? .remove ? ? ? ? = i2c_device_remove,
? ? ? ? .shutdown ? ? ? = i2c_device_shutdown,
? ? ? ? .pm ? ? ? ? ? ? = &i2c_device_pm_ops,
};????????name总线名称,struct bus_attribute,struct device_attribute,struct driver_attribut为总线,设备,驱动属性和方法
????????match为设备和驱动匹配函数,uevent内核向用户通知事件,probe探测函数,remove移除函数,shutdown关闭函数,suspend挂起,resume唤醒,struct dev_pm_ops *pm;电源管理,struct bus_type_private *p;私有数据
struct bus_type_private {
?? ?struct kset subsys;
?? ?struct kset *drivers_kset;
?? ?struct kset *devices_kset;
?? ?struct klist klist_devices;
?? ?struct klist klist_drivers;
?? ?struct blocking_notifier_head bus_notifier;
?? ?unsigned int drivers_autoprobe:1;
?? ?struct bus_type *bus;
};????????struct kset subsys;总线子系统,kobj为子系统顶层目录
????????struct kset *drivers_kset;struct kset *devices_kset;挂载到该总线上的驱动和设备集合
????????struct klist klist_devices;struct klist klist_drivers;设备和驱动链表
????????unsigned int drivers_autoprobe:1;注册时自动探测设备
????????struct bus_type *bus;回指针
设备
struct device
{
?? ?struct device?? ??? ?*parent;
?? ?struct device_private?? ?*p;
?? ?struct kobject kobj;
?? ?const char?? ??? ?*init_name; /* initial name of the device */
?? ?struct device_type?? ?*type;
?? ?struct mutex?? ??? ?mutex;?? ?/* mutex to synchronize calls to
?? ??? ??? ??? ??? ? * its driver.
?? ??? ??? ??? ??? ? */
?? ?struct bus_type?? ?*bus;?? ??? ?/* type of bus device is on */
?? ?struct device_driver *driver;?? ?/* which driver has allocated this
?? ??? ??? ??? ??? ? ? device */
?? ?void?? ??? ?*platform_data;?? ?/* Platform specific data, device
?? ??? ??? ??? ??? ? ? core doesn't touch it */
?? ?struct dev_pm_info?? ?power;
#ifdef CONFIG_NUMA
?? ?int?? ??? ?numa_node;?? ?/* NUMA node this device is close to */
#endif
?? ?u64?? ??? ?*dma_mask;?? ?/* dma mask (if dma'able device) */
?? ?u64?? ??? ?coherent_dma_mask;/* Like dma_mask, but for
?? ??? ??? ??? ??? ? ? ? alloc_coherent mappings as
?? ??? ??? ??? ??? ? ? ? not all hardware supports
?? ??? ??? ??? ??? ? ? ? 64 bit addresses for consistent
?? ??? ??? ??? ??? ? ? ? allocations such descriptors. */
?? ?struct device_dma_parameters *dma_parms;
?? ?struct list_head?? ?dma_pools;?? ?/* dma pools (if dma'ble) */
?? ?struct dma_coherent_mem?? ?*dma_mem; /* internal for coherent mem
?? ??? ??? ??? ??? ? ? ? override */
?? ?/* arch specific additions */
?? ?struct dev_archdata?? ?archdata;
#ifdef CONFIG_OF
?? ?struct device_node?? ?*of_node;
#endif
?? ?dev_t?? ??? ??? ?devt;?? ?/* dev_t, creates the sysfs "dev" */
?? ?spinlock_t?? ??? ?devres_lock;
?? ?struct list_head?? ?devres_head;
?? ?struct klist_node?? ?knode_class;
?? ?struct class?? ??? ?*class;
?? ?const struct attribute_group **groups;?? ?/* optional groups */
?? ?void?? ?(*release)(struct device *dev);
}????????device结构体用于描述设备
????????struct device?? ??? ?*parent;父设备
????????struct device_private?? ?*p;私有数据
struct device_private {
?? ?struct klist klist_children;
?? ?struct klist_node knode_parent;
?? ?struct klist_node knode_driver;
?? ?struct klist_node knode_bus;
?? ?void *driver_data;
?? ?struct device *device;
};????????const char?? ??? ?*init_name;设备名
????????struct bus_type?? ?*bus;指向总线
????????struct device_type?? ?*type;设备处理函数
??struct device_type {
?? ?const char *name;
?? ?const struct attribute_group **groups;
?? ?int (*uevent)(struct device *dev, struct kobj_uevent_env *env);
?? ?char *(*devnode)(struct device *dev, mode_t *mode);
?? ?void (*release)(struct device *dev);
?? ?const struct dev_pm_ops *pm;
};????????struct device_driver *driver;设备驱动
????????struct kobject kobj;内嵌kobject
struct kobject {
?? ?const char?? ??? ?*name;
?? ?struct list_head?? ?entry;
?? ?struct kobject?? ??? ?*parent;
?? ?struct kset?? ??? ?*kset;
?? ?struct kobj_type?? ?*ktype;
?? ?struct sysfs_dirent?? ?*sd;
?? ?struct kref?? ??? ?kref;
?? ?unsigned int state_initialized:1;
?? ?unsigned int state_in_sysfs:1;
?? ?unsigned int state_add_uevent_sent:1;
?? ?unsigned int state_remove_uevent_sent:1;
?? ?unsigned int uevent_suppress:1;
};?????????void?? ?(*release)(struct device *dev);释放设备回调函数
????????dev_t?? ??? ??? ?devt;设备号
????????struct class?? ??? ?*class;设备类类指针
????????void?? ??? ?*platform_data;平台设备数据(gpio、中断号、设备名称等)
设备注册和注销
int device_register(struct device *dev);
void device_unregister(struct device *dev);宏DEVICE_ATTR定义attribute结构
#define DEVICE_ATTR(_name, _mode, _show, _store) \
struct device_attribute dev_attr_##_name = __ATTR(_name, _mode, _show, _store)创建和删除device目录下的属性文件
int device_create_file(struct device *dev,const struct device_attribute *attr);
void device_remove_file(struct device *dev,const struct device_attribute *attr);驱动
struct device_driver {
?? ?const char?? ??? ?*name;
?? ?struct bus_type?? ??? ?*bus;
?? ?struct module?? ??? ?*owner;
?? ?const char?? ??? ?*mod_name;?? ?/* used for built-in modules */
?? ?bool suppress_bind_attrs;?? ?/* disables bind/unbind via sysfs */
#if defined(CONFIG_OF)
?? ?const struct of_device_id?? ?*of_match_table;
#endif
?? ?int (*probe) (struct device *dev);
?? ?int (*remove) (struct device *dev);
?? ?void (*shutdown) (struct device *dev);
?? ?int (*suspend) (struct device *dev, pm_message_t state);
?? ?int (*resume) (struct device *dev);
?? ?const struct attribute_group **groups;
?? ?const struct dev_pm_ops *pm;
?? ?struct driver_private *p;
}????????const char?? ??? ?*name;驱动名字与设备名字相同总线match匹配函数才可对应找到
????????struct bus_type?? ??? ?*bus;指向驱动总线
????????const char?? ??? ?*mod_name;驱动模块名字
????????probe驱动探测方法(装载使用),remove删除驱动,shutdown关闭驱动方法,suspend挂起方法,resume唤醒方法
????????struct driver_private *p;设备驱动私有数据
struct driver_private {
?? ?struct kobject kobj;
?? ?struct klist klist_devices;
?? ?struct klist_node knode_bus;
?? ?struct module_kobject *mkobj;
?? ?struct device_driver *driver;
};????????const struct attribute_group **groups;驱动属性组
struct attribute_group {
?? ?const char?? ??? ?*name;
?? ?mode_t?? ??? ??? ?(*is_visible)(struct kobject *,
?? ??? ??? ??? ??? ? ? ? ?struct attribute *, int);
?? ?struct attribute?? ?**attrs;
};驱动程序注册和注销
int driver_register(struct device_driver *drv);
void driver_unregister(struct device_driver *drv);驱动属性文件删除和创建
int driver_create_file(struct device_driver *drv,?const struct driver_attribute *attr);
void driver_remove_file(struct device_driver *drv,const struct driver_attribute *attr);platform(drivers/base/platform.c)
????????平台设备:wdt、i2c、i2s、rtc,adc等
????????CPU与外部通信：地址总线、专用接口
????????平台总线为地址总线式连接设备(soc内部外设)
平台设备(struct platform_device)
struct platform_device {
?? ?const char?? ?* name;
?? ?int?? ??? ?id;
?? ?struct device?? ?dev;
?? ?u32?? ??? ?num_resources;
?? ?struct resource?? ?* resource;
?? ?const struct platform_device_id?? ?*id_entry;
?? ?/* arch specific additions */
?? ?struct pdev_archdata?? ?archdata;
};????????name设备名,struct device?? ?dev;设备结构体
????????const struct platform_device_id?? ?*id_entry;设备ID表
????????struct pdev_archdata?? ?archdata;预留
????????struct resource?? ?* resource;资源数组
????????u32 num_resources;设备使用资源数量
struct resource {
?? ?resource_size_t start;
?? ?resource_size_t end;
?? ?const char *name;
?? ?unsigned long flags;
?? ?struct resource *parent, *sibling, *child;
};static struct resource s3c_wdt_resource[] = {
? ? ? ? [0] = {
? ? ? ? ? ? ? ? .start ?= S3C_PA_WDT,
? ? ? ? ? ? ? ? .end ? ?= S3C_PA_WDT + SZ_1M - 1,
? ? ? ? ? ? ? ? .flags ?= IORESOURCE_MEM,
? ? ? ? },
? ? ? ? [1] = {
? ? ? ? ? ? ? ? .start ?= IRQ_WDT,
? ? ? ? ? ? ? ? .end ? ?= IRQ_WDT,
? ? ? ? ? ? ? ? .flags ?= IORESOURCE_IRQ,
? ? ? ? }
};????????start资源起始地址(WTCON),资源结束地址,name资源名,flags资源类型(IORESOURCE_MEM内存资源)
????????start资源起始地址(IRQ_WDT中断开始信号),资源结束地址(IRQ_WDT中断结束信号),flags资源类型(IORESOURCE_IRQ中断资源)
????????flags标志：I/O端口(IORESOURCE_IO)、内存资源(IORESOURCE_MEM)、中断号(IORESOURCE_IRQ)、DMA资源(IORESOURCE_DMA)?
????????struct resource *parent, *sibling, *child;构建资源设备树
平台设备函数
int platform_device_add(struct platform_device *pdev);
void platform_device_del(struct platform_device *pdev);
int platform_device_register(struct platform_device *pdev);
void platform_device_unregister(struct platform_device *pdev);
struct resource *platform_get_resource(struct platform_device *dev,unsigned int type, unsigned int num);平台设备驱动
struct platform_driver {
?? ?int (*probe)(struct platform_device *);
?? ?int (*remove)(struct platform_device *);
?? ?void (*shutdown)(struct platform_device *);
?? ?int (*suspend)(struct platform_device *, pm_message_t state);
?? ?int (*resume)(struct platform_device *);
?? ?struct device_driver driver;
?? ?const struct platform_device_id *id_table;
};????????struct device_driver driver;设备驱动结构体
????????const struct platform_device_id *id_table;设备ID表
????????probe驱动探测方法(装载使用),remove删除驱动,shutdown关闭驱动方法,suspend挂起方法,resume唤醒方法
平台驱动注册(probe)和注销(remove)
int platform_driver_register(struct platform_driver *drv);
void platform_driver_unregister(struct platform_driver *drv);misc
????????杂项主设备号通常为10
????????设备类文件:/sys/class/misc
混杂设备
struct miscdevice ?{
?? ?int minor;
?? ?const char *name;
?? ?const struct file_operations *fops;
?? ?struct list_head list;
?? ?struct device *parent;
?? ?struct device *this_device;
?? ?const char *nodename;
?? ?mode_t mode;
};????????minor次设备号,name设备名,fops设备操作函数,this_device当前设备指针
混杂设备的注册和注销
int misc_register(struct miscdevice * misc);
int misc_deregister(struct miscdevice *misc);210蜂鸣器(x210-buzzer.c)
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/poll.h>
#include <asm/irq.h>
#include <asm/io.h>
#include <linux/interrupt.h>
#include <asm/uaccess.h>
#include <mach/hardware.h>
#include <plat/regs-timer.h>
#include <mach/regs-irq.h>
#include <asm/mach/time.h>
#include <linux/clk.h>
#include <linux/cdev.h>
#include <linux/device.h>
#include <linux/miscdevice.h>
#include <linux/gpio.h>
#include <plat/gpio-cfg.h>
//定义设备名
#define DEVICE_NAME ? ? "buzzer"
//定义cmd
#define PWM_IOCTL_SET_FREQ?? ??? ?1
#define PWM_IOCTL_STOP?? ??? ??? ?0
//定义信号量
static struct semaphore lock;
//初始化buzzer,设置频率
// TCFG0在Uboot中设置，这里不再重复设置
// Timer0输入频率Finput=pclk/(prescaler1+1)/MUX1=66M/16/16
// TCFG0 = tcnt = (pclk/16/16)/freq;
// PWM0输出频率Foutput =Finput/TCFG0= freq
static void PWM_Set_Freq( unsigned long freq )
{
?? ?unsigned long tcon;
?? ?unsigned long tcnt;
?? ?unsigned long tcfg1;
?? ?struct clk *clk_p;
?? ?unsigned long pclk;
?? ?//unsigned tmp;
?? ?
?? ?//设置GPD0_2为PWM输出
?? ?s3c_gpio_cfgpin(S5PV210_GPD0(2), S3C_GPIO_SFN(2));
?? ?tcon = __raw_readl(S3C2410_TCON);
?? ?tcfg1 = __raw_readl(S3C2410_TCFG1);
?? ?//mux = 1/16
?? ?tcfg1 &= ~(0xf<<8);
?? ?tcfg1 |= (0x4<<8);
?? ?__raw_writel(tcfg1, S3C2410_TCFG1);
?? ?
?? ?clk_p = clk_get(NULL, "pclk");
?? ?pclk ?= clk_get_rate(clk_p);
?? ?tcnt ?= (pclk/16/16)/freq;
?? ?
?? ?__raw_writel(tcnt, S3C2410_TCNTB(2));
?? ?__raw_writel(tcnt/2, S3C2410_TCMPB(2));//占空比为50%
?? ?tcon &= ~(0xf<<12);
?? ?tcon |= (0xb<<12);?? ??? ?//disable deadzone, auto-reload, inv-off, update TCNTB0&TCMPB0, start timer 0
?? ?__raw_writel(tcon, S3C2410_TCON);
?? ?
?? ?tcon &= ~(2<<12);?? ??? ??? ?//clear manual update bit
?? ?__raw_writel(tcon, S3C2410_TCON);
}
//停止buzzer(改为输入模式)
void PWM_Stop( void )
{
?? ?//将GPD0_2设置为input
?? ?s3c_gpio_cfgpin(S5PV210_GPD0(2), S3C_GPIO_SFN(0));?? ?
}
//对应open,开锁
static int x210_pwm_open(struct inode *inode, struct file *file)
{
?? ?if (!down_trylock(&lock))
?? ??? ?return 0;
?? ?else
?? ??? ?return -EBUSY;
?? ?
}
//对应close,上锁
static int x210_pwm_close(struct inode *inode, struct file *file)
{
?? ?up(&lock);
?? ?return 0;
}
// PWM:GPF14->PWM0(接收cmd,设置频率,关闭buzzer)
static int x210_pwm_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
{
?? ?switch (cmd)?
?? ?{
?? ??? ?case PWM_IOCTL_SET_FREQ:
?? ??? ??? ?printk("PWM_IOCTL_SET_FREQ:\r\n");
?? ??? ??? ?if (arg == 0)
?? ??? ??? ??? ?return -EINVAL;
?? ??? ??? ?PWM_Set_Freq(arg);
?? ??? ??? ?break;
?? ??? ?case PWM_IOCTL_STOP:
?? ??? ?default:
?? ??? ??? ?printk("PWM_IOCTL_STOP:\r\n");
?? ??? ??? ?PWM_Stop();
?? ??? ??? ?break;
?? ?}
?? ?return 0;
}
static struct file_operations dev_fops = {
? ? .owner ? = ? THIS_MODULE,
? ? .open ? ?= ? x210_pwm_open,
? ? .release = ? x210_pwm_close,?
? ? .ioctl ? = ? x210_pwm_ioctl,
};
//定义msic设备
static struct miscdevice misc = {
?? ?.minor = MISC_DYNAMIC_MINOR,
?? ?.name = DEVICE_NAME,
?? ?.fops = &dev_fops,
};
//驱动装载
static int __init dev_init(void)
{
?? ?int ret;
?? ?init_MUTEX(&lock);
?? ?ret = misc_register(&misc);
?? ?
?? ?/* GPD0_2 (PWMTOUT2) */
?? ?ret = gpio_request(S5PV210_GPD0(2), "GPD0");
?? ?if(ret)
?? ??? ?printk("buzzer-x210: request gpio GPD0(2) fail");
?? ??? ?
?? ?s3c_gpio_setpull(S5PV210_GPD0(2), S3C_GPIO_PULL_UP);
?? ?s3c_gpio_cfgpin(S5PV210_GPD0(2), S3C_GPIO_SFN(1));
?? ?gpio_set_value(S5PV210_GPD0(2), 0);
?? ?printk ("x210 "DEVICE_NAME" initialized\n");
? ? ?? ?return ret;
}
//驱动卸载
static void __exit dev_exit(void)
{
?? ?misc_deregister(&misc);
}
module_init(dev_init);
module_exit(dev_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("www.9tripod.com");
MODULE_DESCRIPTION("x210 PWM Driver");buzzer.c
?
#include <stdio.h>
#include <sys/stat.h>
#include <fcntl.h>
#define DEVNAME "/dev/buzzer"
#define PWM_IOCTL_SET_FREQ 1
#define PWM_IOCTL_STOP 0
int main(void)
{
int fd = -1;
fd = open(DEVNAME, O_RDWR);
if (fd < 0)
{
perror("open");
return -1;
}
ioctl(fd, PWM_IOCTL_SET_FREQ, 10000);
sleep(3);
ioctl(fd, PWM_IOCTL_STOP);
close(fd);
}demo:
? ? ? ? 使用平台总线方式驱动led(模仿leds-s3c24xx.c)
Makefile
KERN_DIR = /root/kernel
obj-m += x210-led.o
all:
make -C $(KERN_DIR) M=`pwd` modules
cp:
cp *.ko /root/rootfs/driver
.PHONY: clean
clean:
make -C $(KERN_DIR) M=`pwd` modules clean?x210-led.c
#include <linux/module.h>
#include <linux/init.h>
#include <linux/fs.h>
#include <linux/leds.h>
#include <mach/regs-gpio.h>
#include <mach/gpio-bank.h>
#include <linux/io.h>
#include <linux/ioport.h>
#include <mach/gpio.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <mach/leds_x210-gpio.h>
#define LED_OFF 1
#define LED_ON 0
struct s5pv210_gpio_led
{
struct led_classdev cdev;
struct s5pv210_led_platdata *pdata;
};
static inline struct s5pv210_gpio_led *pdev_to_gpio(struct platform_device *dev)
{
return platform_get_drvdata(dev);
}
static inline struct s5pv210_gpio_led *to_gpio(struct led_classdev *led_cdev)
{
return container_of(led_cdev, struct s5pv210_gpio_led, cdev);
}
static void s5pv210_led_set(struct led_classdev *led_cdev,enum led_brightness value)
{
struct s5pv210_gpio_led *p = to_gpio(led_cdev);
if(value == LED_OFF)
{
gpio_set_value(p->pdata->gpio,LED_OFF);
}
else
{
gpio_set_value(p->pdata->gpio,LED_ON);
}
}
int s5pv210_led_probe(struct platform_device *dev)
{
int ret = -1;
struct s5pv210_led_platdata *pdata = dev->dev.platform_data;
struct s5pv210_gpio_led *led;
led = kzalloc(sizeof(struct s5pv210_gpio_led), GFP_KERNEL);
if (led == NULL) {
dev_err(&dev->dev, "No memory for device\n");
return -ENOMEM;
}
platform_set_drvdata(dev, led);
ret = gpio_request(pdata->gpio, pdata->name);
if (ret != 0)
{
printk(KERN_ERR "gpio_request failed %d\n",ret);
return ret;
}
else
{
gpio_direction_output(pdata->gpio,GPIOF_OUT_INIT_HIGH);
}
led->cdev.name = pdata->name;
led->cdev.brightness = 0;
led->cdev.brightness_set = s5pv210_led_set;
led->pdata = pdata;
ret = led_classdev_register(&dev->dev, &led->cdev);
if (ret < 0)
{
printk(KERN_ERR "led classdev register failed\n");
kfree(led);
return ret;
}
return 0;
}
static int s5pv210_led_remove(struct platform_device *dev)
{
struct s5pv210_gpio_led *p = pdev_to_gpio(dev);
led_classdev_unregister(&p->cdev);
gpio_free(p->pdata->gpio);
kfree(p);
return 0;
}
struct platform_driver s5pv210_led_driver[] ={
[0] = {
.probe = s5pv210_led_probe,
.remove = s5pv210_led_remove,
.driver = {
.name = "led1",
.owner = THIS_MODULE,
}},
[1] = {
.probe = s5pv210_led_probe,
.remove = s5pv210_led_remove,
.driver = {
.name = "led2",
.owner = THIS_MODULE,
}},
[2] = {
.probe = s5pv210_led_probe,
.remove = s5pv210_led_remove,
.driver = {
.name = "led3",
.owner = THIS_MODULE,
}},
};
static int __init led_dev_init(void)
{
platform_driver_register(&s5pv210_led_driver[0]);
platform_driver_register(&s5pv210_led_driver[1]);
platform_driver_register(&s5pv210_led_driver[2]);
return 0;
}
static void __exit led_dev_exit(void)
{
platform_driver_unregister(&s5pv210_led_driver[0]);
platform_driver_unregister(&s5pv210_led_driver[1]);
platform_driver_unregister(&s5pv210_led_driver[2]);
}
module_init(led_dev_init);
module_exit(led_dev_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("cxb");
MODULE_DESCRIPTION("led gpio module");
MODULE_ALIAS("led");操作流程?
vim arch/arm/mach-s5cpv210/include/mach/leds_x210-gpio.h
添加设备特殊数据结构体(gpio、中断号、设备名称等)
#ifndef __ASM_ARCH_LEDSGPIO_H
#define __ASM_ARCH_LEDSGPIO_H "leds-gpio.h"
#define S5PV210_LEDF_ACTLOW (1<<0) /* LED is on when GPIO low */
#define S5PV210_LEDF_TRISTATE (1<<1) /* tristate to turn off */
struct s5pv210_led_platdata {
unsigned int gpio;
unsigned int flags;
char *name;
char *def_trigger;
};
#endif /* __ASM_ARCH_LEDSGPIO_H */
vim arch/arm/mach-s5pv210/mach-x210.c
添加设备特殊数据结构体
#include <mach/leds_x210-gpio.h>
定义如下平台总线设备到smdkc110_devices[]前
static struct s5pv210_led_platdata x210_led1_pdata = {
.name = "led1",
.gpio = S5PV210_GPJ0(3),
.flags = S5PV210_LEDF_ACTLOW | S5PV210_LEDF_TRISTATE,
.def_trigger = "",
};
static struct platform_device x210_led1 = {
.name = "led1",
.id = 0,
.dev = {
.platform_data = &x210_led1_pdata,
},
};
static struct s5pv210_led_platdata x210_led2_pdata = {
.name = "led2",
.gpio = S5PV210_GPJ0(4),
.flags = S5PV210_LEDF_ACTLOW | S5PV210_LEDF_TRISTATE,
.def_trigger = "",
};
static struct platform_device x210_led2 = {
.name = "led2",
.id = 1,
.dev = {
.platform_data = &x210_led2_pdata,
},
};
static struct s5pv210_led_platdata x210_led3_pdata = {
.name = "led3",
.gpio = S5PV210_GPJ0(5),
.flags = S5PV210_LEDF_ACTLOW | S5PV210_LEDF_TRISTATE,
.def_trigger = "",
};
static struct platform_device x210_led3 = {
.name = "led3",
.id = 2,
.dev = {
.platform_data = &x210_led3_pdata,
},
};
添加如下平台总线设备到smdkc110_devices[]
&x210_led1
&x210_led2
&x210_led3
make -j8 && cp arch/arm/boot/zImage ~/tftp -f
make cp结果示例：
文章来源:https://blog.csdn.net/tyro_wzp/article/details/135492153
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本文来自互联网用户投稿，该文观点仅代表作者本人，不代表本站立场。本站仅提供信息存储空间服务，不拥有所有权，不承担相关法律责任。 如若内容造成侵权/违法违规/事实不符，请联系我的编程经验分享网邮箱：veading@qq.com进行投诉反馈，一经查实，立即删除！