网站建设要注意些什么,wordpress分类目录seo标题,WordPress动态二维码插件,北京科技公司名称以下内容源于朱有鹏嵌入式课程的学习整理#xff0c;如有侵权请告知删除。 一、前言 在实际情况中#xff0c;很多硬件都要用到GPIO#xff0c;因此GPIO会复用#xff1b;如果同一个GPIO被2个驱动同时控制就会出现bug#xff1b;因此内核提供了gpiolib来统一管理系统中所有…以下内容源于朱有鹏嵌入式课程的学习整理如有侵权请告知删除。 一、前言 在实际情况中很多硬件都要用到GPIO因此GPIO会复用如果同一个GPIO被2个驱动同时控制就会出现bug因此内核提供了gpiolib来统一管理系统中所有GPIO。某个驱动需要用到GPIO时需要申请被许可后才可以使用使用完后释放其他驱动才能使用该GPIO。 在LED驱动框架的分析文章开头写到“系统资源的管控属于驱动框架的一部分”。gpiolib体系也属于驱动框架的一部分。 二、gpiolib体系的3条主线 第1条主线gpiolib的建立过程。 第2条主线gpiolib的使用方法即申请、使用、释放。 第3条主线gpiolib的架构即涉及哪些目录的哪些文件。 三、第一条主线gpiolib的建立过程 s5pv210_gpiolib_init()函数是gpiolib初始化的函数。 其定义在x210_kernel\arch\arm\mach-s5pv210\gpiolib.c文件中。 static void __init smdkc110_map_io(void)
{s5p_init_io(NULL, 0, S5P_VA_CHIPID);s3c24xx_init_clocks(24000000);s5pv210_gpiolib_init();//这里s3c24xx_init_uarts(smdkc110_uartcfgs, ARRAY_SIZE(smdkc110_uartcfgs));s5p_reserve_bootmem(smdkc110_media_devs, ARRAY_SIZE(smdkc110_media_devs));
#ifdef CONFIG_MTD_ONENANDs5pc110_device_onenand.name s5pc110-onenand;
#endif
#ifdef CONFIG_MTD_NANDs3c_device_nand.name s5pv210-nand;
#endifs5p_device_rtc.name smdkc110-rtc;
}__init int s5pv210_gpiolib_init(void)
{struct s3c_gpio_chip *chip s5pv210_gpio_4bit;//结构体数组int nr_chips ARRAY_SIZE(s5pv210_gpio_4bit);//GPIO端口数目int i 0;for (i 0; i nr_chips; i, chip) {if (chip-config NULL)chip-config gpio_cfg;if (chip-base NULL)chip-base S5PV210_BANK_BASE(i);}samsung_gpiolib_add_4bit_chips(s5pv210_gpio_4bit, nr_chips);return 0;
}1、结构体struct s3c_gpio_chip的分析 该结构体定义在\x210_kernel\arch\arm\plat-samsung\include\plat\gpio-core.h文件中。它是一个GPIO端口的抽象。 端口和IO口是两个概念。S5PV210的IO口约有160个这些IO口被分成N个端口每个端口中又包含了M个IO口。比如GPA0就是一个端口里面包含8个IO口一般记作GPA0_0或GPA0.0GPA0_1或GPA0.1…GPA0_7或GPA0.7。 内核中为每个GPIO都分配了一个编号编号是一个数字比如有160个IO时编号就可以从1到160连续分布编号可以让程序很方便的去识别每一个GPIO。 struct s3c_gpio_chip {struct gpio_chip chip;struct s3c_gpio_cfg *config;struct s3c_gpio_pm *pm;void __iomem *base;//端口的基地址int eint_offset;spinlock_t lock;
#ifdef CONFIG_PMu32 pm_save[7];
#endif
}; 该结构体包括着结构体struct gpio_chip其内容如下 struct gpio_chip {const char *label;//端口的名字struct device *dev;struct module *owner;int (*request)(struct gpio_chip *chip,unsigned offset);void (*free)(struct gpio_chip *chip,unsigned offset);int (*direction_input)(struct gpio_chip *chip,unsigned offset);int (*get)(struct gpio_chip *chip,unsigned offset);int (*direction_output)(struct gpio_chip *chip,unsigned offset, int value);int (*set_debounce)(struct gpio_chip *chip,unsigned offset, unsigned debounce);void (*set)(struct gpio_chip *chip,unsigned offset, int value);int (*to_irq)(struct gpio_chip *chip,unsigned offset);void (*dbg_show)(struct seq_file *s,struct gpio_chip *chip);int base;///u16 ngpio;const char *const *names;unsigned can_sleep:1;unsigned exported:1;
}; 2、结构体数组s5pv210_gpio_4bit 该数组定义在x210_kernel\arch\arm\mach-s5pv210\gpiolib.c文件中。 该数组的成员都是struct s3c_gpio_chip结构体类型的变量在定义数组的同时都填充了每个成员的chip这个元素。 结构体数组s5pv210_gpio_4bit包含了当前系统中所有的IO端口的信息比如端口的名字、端口中所有GPIO的编号、端口操作寄存器组的虚拟地址基地址、端口中IO口的数量、端口上下拉等模式的配置函数、端口中的IO口换算其对应的中断号的函数。 static struct s3c_gpio_chip s5pv210_gpio_4bit[] {{.chip {.base S5PV210_GPA0(0), //当前端口的基础编号.ngpio S5PV210_GPIO_A0_NR,//当前端口拥有的IO口数量.label GPA0, //当前端口的名字.to_irq s5p_gpiolib_gpioint_to_irq,//当前端口中IO口换成对应中断号的方法},}, {.chip {.base S5PV210_GPA1(0),.ngpio S5PV210_GPIO_A1_NR,.label GPA1,.to_irq s5p_gpiolib_gpioint_to_irq,},}, {.chip {.base S5PV210_GPB(0),.ngpio S5PV210_GPIO_B_NR,.label GPB,.to_irq s5p_gpiolib_gpioint_to_irq,},},
//……省略部分代码
} [rootxjh class]# ls
backlight i2c-adapter misc regulator scsi_host //忽略部分
bdi i2c-dev mmc_host rfkill sound
block ieee80211 mtd rtc spi_master
firmware input net s3c_bc switch
gpio lcd power_supply scsi_device timed_output
graphics leds ppp scsi_disk tty
hidraw mem pvr scsi_generic vc
[rootxjh class]# cd gpio/
[rootxjh gpio]# ls
export gpiochip164 gpiochip235 gpiochip316 gpiochip396 gpiochip56
gpiochip0 gpiochip172 gpiochip244 gpiochip325 gpiochip40 gpiochip62
gpiochip104 gpiochip181 gpiochip253 gpiochip334 gpiochip405 gpiochip71
gpiochip112 gpiochip188 gpiochip262 gpiochip343 gpiochip414 gpiochip80
gpiochip120 gpiochip197 gpiochip271 gpiochip35 gpiochip423 gpiochip89
gpiochip128 gpiochip206 gpiochip280 gpiochip351 gpiochip431 gpiochip9
gpiochip137 gpiochip212 gpiochip289 gpiochip360 gpiochip438 gpiochip96
gpiochip14 gpiochip221 gpiochip29 gpiochip369 gpiochip447 unexport
gpiochip146 gpiochip226 gpiochip298 gpiochip378 gpiochip456
gpiochip155 gpiochip23 gpiochip307 gpiochip387 gpiochip47
[rootxjh gpio]# cd gpiochip0
[rootxjh gpiochip0]# ls
base label ngpio power subsystem uevent
[rootxjh gpiochip0]# cat base
0
[rootxjh gpiochip0]# cat label
GPA0
[rootxjh gpiochip0]# cat ngpio
8
[rootxjh gpiochip0]# cd ../gpiochip14
[rootxjh gpiochip14]# ls
base label ngpio power subsystem uevent
[rootxjh gpiochip14]# cat base
14
[rootxjh gpiochip14]# cat label
GPB
[rootxjh gpiochip14]# cat ngpio
8
[rootxjh gpiochip14]# cd ../gpiochip35
[rootxjh gpiochip35]# ls
base label ngpio power subsystem uevent
[rootxjh gpiochip35]# cat base
35
[rootxjh gpiochip35]# cat label
GPD0
[rootxjh gpiochip35]# cat ngpio
4
[rootxjh gpiochip35]# 另外注意一下诸如S5PV210_GPA0()这样的宏。这个宏的返回值是GPA0端口的某一个IO口的基础编号值传参是这个IO口在GPA0端口中的局部编号。 /* S5PV210 GPIO number definitions */
#define S5PV210_GPA0(_nr) (S5PV210_GPIO_A0_START (_nr))
#define S5PV210_GPA1(_nr) (S5PV210_GPIO_A1_START (_nr))
#define S5PV210_GPB(_nr) (S5PV210_GPIO_B_START (_nr))
#define S5PV210_GPC0(_nr) (S5PV210_GPIO_C0_START (_nr))
#define S5PV210_GPC1(_nr) (S5PV210_GPIO_C1_START (_nr))
…… #define S5PV210_GPIO_NEXT(__gpio) \((__gpio##_START) (__gpio##_NR) CONFIG_S3C_GPIO_SPACE 1)enum s5p_gpio_number {S5PV210_GPIO_A0_START 0,S5PV210_GPIO_A1_START S5PV210_GPIO_NEXT(S5PV210_GPIO_A0),S5PV210_GPIO_B_START S5PV210_GPIO_NEXT(S5PV210_GPIO_A1),S5PV210_GPIO_C0_START S5PV210_GPIO_NEXT(S5PV210_GPIO_B),S5PV210_GPIO_C1_START S5PV210_GPIO_NEXT(S5PV210_GPIO_C0),S5PV210_GPIO_D0_START S5PV210_GPIO_NEXT(S5PV210_GPIO_C1),S5PV210_GPIO_D1_START S5PV210_GPIO_NEXT(S5PV210_GPIO_D0),
……
} 3、samsung_gpiolib_add_4bit_chips()函数 该函数的函数名中为什么有个“4bit”查询原理图得知如下。三星的CPU中2440的CON寄存器是2bit对应一个IO口而6410和210以及之后的系列中CON寄存器是4bit对应1个IO口。所以gpiolib在操作2440和210的CON寄存器时是不同的。 此函数用来注册gpiolib接收的参数是结构体数组s5pv210_gpio_4bit、该数组元素的个数。 samsung_gpiolib_add_4bit_chips(s5pv210_gpio_4bit, nr_chips); 函数调用关系如下 |…………samsung_gpiolib_add_4bit_chips()函数 |………………samsung_gpiolib_add_4bit()函数 |……………………samsung_gpiolib_4bit_input函数 |……………………samsung_gpiolib_4bit_output函数 |………………s3c_gpiolib_add()函数 void __init samsung_gpiolib_add_4bit_chips(struct s3c_gpio_chip *chip,int nr_chips)
{for (; nr_chips 0; nr_chips--, chip) {samsung_gpiolib_add_4bit(chip);s3c_gpiolib_add(chip);}
} 查阅代码可知samsung_gpiolib_add_4bit()函数内部没有做gpiolib的注册工作而是在做填充填充的是每一个GPIO被设置成输入模式/输出模式的操作方法。 static int samsung_gpiolib_4bit_input(struct gpio_chip *chip,unsigned int offset)
{struct s3c_gpio_chip *ourchip to_s3c_gpio(chip);void __iomem *base ourchip-base;unsigned long con;con __raw_readl(base GPIOCON_OFF);//读写三部曲con ~(0xf con_4bit_shift(offset));__raw_writel(con, base GPIOCON_OFF);gpio_dbg(%s: %p: CON now %08lx\n, __func__, base, con);return 0;
} 查阅代码可知s3c_gpiolib_add()首先完善chip的direction_input/direction_ouput/set/get这4个方法然后调用gpiochip_add方法进行真正的注册操作。 __init void s3c_gpiolib_add(struct s3c_gpio_chip *chip)
{struct gpio_chip *gc chip-chip;int ret;BUG_ON(!chip-base);BUG_ON(!gc-label);BUG_ON(!gc-ngpio);spin_lock_init(chip-lock);if (!gc-direction_input)gc-direction_input s3c_gpiolib_input;if (!gc-direction_output)gc-direction_output s3c_gpiolib_output;if (!gc-set)gc-set s3c_gpiolib_set;//设置data寄存器的值if (!gc-get)gc-get s3c_gpiolib_get;//获取data寄存器的值#ifdef CONFIG_PMif (chip-pm ! NULL) {if (!chip-pm-save || !chip-pm-resume)printk(KERN_ERR gpio: %s has missing PM functions\n,gc-label);} elseprintk(KERN_ERR gpio: %s has no PM function\n, gc-label);
#endif/* gpiochip_add() prints own failure message on error. */ret gpiochip_add(gc);if (ret 0)s3c_gpiolib_track(chip);
}static void s3c_gpiolib_set(struct gpio_chip *chip,unsigned offset, int value)
{struct s3c_gpio_chip *ourchip to_s3c_gpio(chip);void __iomem *base ourchip-base;unsigned long flags;unsigned long dat;s3c_gpio_lock(ourchip, flags);dat __raw_readl(base 0x04);dat ~(1 offset);if (value)dat | 1 offset;__raw_writel(dat, base 0x04);s3c_gpio_unlock(ourchip, flags);
}static int s3c_gpiolib_get(struct gpio_chip *chip, unsigned offset)
{struct s3c_gpio_chip *ourchip to_s3c_gpio(chip);unsigned long val;val __raw_readl(ourchip-base 0x04);val offset;val 1;return val;
} /*
*这个注册就是将我们的封装了一个GPIO端口的所有信息的chip结构体变量
*挂接到内核gpiolib模块定义的一个gpio_desc数组中的某一个格子中。
*/
int gpiochip_add(struct gpio_chip *chip)
{unsigned long flags;int status 0;unsigned id;int base chip-base;if ((!gpio_is_valid(base) || !gpio_is_valid(base chip-ngpio - 1)) base 0) {status -EINVAL;goto fail;}spin_lock_irqsave(gpio_lock, flags);if (base 0) {base gpiochip_find_base(chip-ngpio);if (base 0) {status base;goto unlock;}chip-base base;}/* these GPIO numbers must not be managed by another gpio_chip */for (id base; id base chip-ngpio; id) {if (gpio_desc[id].chip ! NULL) {status -EBUSY;break;}}if (status 0) {for (id base; id base chip-ngpio; id) {gpio_desc[id].chip chip;/* REVISIT: most hardware initializes GPIOs as* inputs (often with pullups enabled) so power* usage is minimized. Linux code should set the* gpio direction first thing; but until it does,* we may expose the wrong direction in sysfs.*/gpio_desc[id].flags !chip-direction_input? (1 FLAG_IS_OUT): 0;}}unlock:spin_unlock_irqrestore(gpio_lock, flags);if (status 0)status gpiochip_export(chip);
fail:/* failures here can mean systems wont boot... */if (status)pr_err(gpiochip_add: gpios %d..%d (%s) failed to register\n,chip-base, chip-base chip-ngpio - 1,chip-label ? : generic);return status;
}四、第2条主线gpiolib的使用方法 1、从驱动框架角度分析gpiolib 目前已经清楚第1条主线即gpiolib的建立过程但这只是厂商驱动工程师负责的那一部分还有另一部分是内核开发者提供的驱动框架的那一部分即第2条主线。 drivers/gpio/gpiolib.c文件中的函数构成第2部分即内核开发者写的gpiolib框架部分。 1gpiochip_add 它是框架提供的接口给厂商驱动工程师用针对某个开发板GPIO的情况对内核进行一定的修改注册用于向内核注册gpiolib标记有多少组端口属性细节等让内核知道具体的GPIO信息。 2gpio_request 它是框架提供的接口给使用gpiolib来编写自己的驱动的驱动工程师用的驱动中要想使用某一个gpio就必须先调用gpio_request接口来向内核的gpiolib部分申请得到允许后才可以去使用这个gpio。 3gpio_free 对应于gpio_request用来释放gpio。 4gpio_request_one、gpio_request_array 这两个是gpio_request的变种。 5gpiochip_is_requested 接口用来判断某一个gpio是否已经被申请。 6gpio_direction_input、gpio_direction_output 接口用来设置GPIO为输入/输出模式注意该函数内部实际并没有对硬件进行操作只是通过chip结构体变量的函数指针调用了将来SoC厂商的驱动工程师写的真正地操作硬件、实现gpio设置成输出模式的那个函数。 7其他接口 以上的接口是给写其他驱动并且用到了gpiolib的人使用的。剩下的函数是gpiolib内部自己的一些功能实现的代码。 2、gpiolib的attribute部分 1CONFIG_GPIO_SYSFS 在内核中很多实现方式都是通过宏来配置的在.config文件有则必然在menuconfig中有。 2GPIO的attribute演示 static ssize_t chip_label_show(struct device *dev,struct device_attribute *attr, char *buf)
{const struct gpio_chip *chip dev_get_drvdata(dev);return sprintf(buf, %s\n, chip-label ? : );
}
static DEVICE_ATTR(label, 0444, chip_label_show, NULL); [rootxjh class]# ls
backlight i2c-adapter misc regulator scsi_host //忽略部分
bdi i2c-dev mmc_host rfkill sound
block ieee80211 mtd rtc spi_master
firmware input net s3c_bc switch
gpio lcd power_supply scsi_device timed_output
graphics leds ppp scsi_disk tty
hidraw mem pvr scsi_generic vc
[rootxjh class]# cd gpio/
[rootxjh gpio]# ls
export gpiochip164 gpiochip235 gpiochip316 gpiochip396 gpiochip56
gpiochip0 gpiochip172 gpiochip244 gpiochip325 gpiochip40 gpiochip62
gpiochip104 gpiochip181 gpiochip253 gpiochip334 gpiochip405 gpiochip71
gpiochip112 gpiochip188 gpiochip262 gpiochip343 gpiochip414 gpiochip80
gpiochip120 gpiochip197 gpiochip271 gpiochip35 gpiochip423 gpiochip89
gpiochip128 gpiochip206 gpiochip280 gpiochip351 gpiochip431 gpiochip9
gpiochip137 gpiochip212 gpiochip289 gpiochip360 gpiochip438 gpiochip96
gpiochip14 gpiochip221 gpiochip29 gpiochip369 gpiochip447 unexport
gpiochip146 gpiochip226 gpiochip298 gpiochip378 gpiochip456
gpiochip155 gpiochip23 gpiochip307 gpiochip387 gpiochip47
[rootxjh gpio]# cd gpiochip0
[rootxjh gpiochip0]# ls
base label ngpio power subsystem uevent
[rootxjh gpiochip0]# cat base
0
[rootxjh gpiochip0]# cat label
GPA0
[rootxjh gpiochip0]# cat ngpio
8
[rootxjh gpiochip0]# 3能够cat的相关代码分析 static int __init gpiolib_sysfs_init(void)
{int status;unsigned long flags;unsigned gpio;idr_init(pdesc_idr);status class_register(gpio_class);在/sys/class里定义了gpio这个类if (status 0)return status;/* Scan and register the gpio_chips which registered very* early (e.g. before the class_register above was called).** We run before arch_initcall() so chip-dev nodes can have* registered, and so arch_initcall() can always gpio_export().*/spin_lock_irqsave(gpio_lock, flags);for (gpio 0; gpio ARCH_NR_GPIOS; gpio) {struct gpio_chip *chip;chip gpio_desc[gpio].chip;if (!chip || chip-exported)continue;spin_unlock_irqrestore(gpio_lock, flags);status gpiochip_export(chip);//spin_lock_irqsave(gpio_lock, flags);}spin_unlock_irqrestore(gpio_lock, flags);return status;
}
postcore_initcall(gpiolib_sysfs_init); static int gpiochip_export(struct gpio_chip *chip)
{int status;struct device *dev;/* Many systems register gpio chips for SOC support very early,* before driver model support is available. In those cases we* export this later, in gpiolib_sysfs_init() ... here we just* verify that _some_ field of gpio_class got initialized.*/if (!gpio_class.p)return 0;/* use chip-base for the ID; its already known to be unique */mutex_lock(sysfs_lock);dev device_create(gpio_class, chip-dev, MKDEV(0, 0), chip,gpiochip%d, chip-base);if (!IS_ERR(dev)) {status sysfs_create_group(dev-kobj,//用来创建许多attributegpiochip_attr_group);} elsestatus PTR_ERR(dev);chip-exported (status 0);mutex_unlock(sysfs_lock);if (status) {unsigned long flags;unsigned gpio;spin_lock_irqsave(gpio_lock, flags);gpio chip-base;while (gpio_desc[gpio].chip chip)gpio_desc[gpio].chip NULL;spin_unlock_irqrestore(gpio_lock, flags);pr_debug(%s: chip %s status %d\n, __func__,chip-label, status);}return status;
} [rootxjh ~]# cd /sys/class
[rootxjh class]# cd gpio/
[rootxjh gpio]# ls
export gpiochip164 gpiochip235 gpiochip316 gpiochip396 gpiochip56
gpiochip0 gpiochip172 gpiochip244 gpiochip325 gpiochip40 gpiochip62
gpiochip104 gpiochip181 gpiochip253 gpiochip334 gpiochip405 gpiochip71
gpiochip112 gpiochip188 gpiochip262 gpiochip343 gpiochip414 gpiochip80
gpiochip120 gpiochip197 gpiochip271 gpiochip35 gpiochip423 gpiochip89
gpiochip128 gpiochip206 gpiochip280 gpiochip351 gpiochip431 gpiochip9
gpiochip137 gpiochip212 gpiochip289 gpiochip360 gpiochip438 gpiochip96
gpiochip14 gpiochip221 gpiochip29 gpiochip369 gpiochip447 unexport
gpiochip146 gpiochip226 gpiochip298 gpiochip378 gpiochip456
gpiochip155 gpiochip23 gpiochip307 gpiochip387 gpiochip47
[rootxjh gpio]# echo 23 export
[rootxjh gpio]# ls
export gpiochip155 gpiochip23 gpiochip307 gpiochip387 gpiochip47
gpio23//多出 gpiochip164 gpiochip235 gpiochip316 gpiochip396 gpiochip56
gpiochip0 gpiochip172 gpiochip244 gpiochip325 gpiochip40 gpiochip62
gpiochip104 gpiochip181 gpiochip253 gpiochip334 gpiochip405 gpiochip71
gpiochip112 gpiochip188 gpiochip262 gpiochip343 gpiochip414 gpiochip80
gpiochip120 gpiochip197 gpiochip271 gpiochip35 gpiochip423 gpiochip89
gpiochip128 gpiochip206 gpiochip280 gpiochip351 gpiochip431 gpiochip9
gpiochip137 gpiochip212 gpiochip289 gpiochip360 gpiochip438 gpiochip96
gpiochip14 gpiochip221 gpiochip29 gpiochip369 gpiochip447 unexport
gpiochip146 gpiochip226 gpiochip298 gpiochip378 gpiochip456
[rootxjh gpio]# cd gpio23
[rootxjh gpio23]# ls
active_low direction edge power subsystem uevent value
[rootxjh gpio23]# cat value
0
[rootxjh gpio23]# cat edge
none
[rootxjh gpio23]# cat direction
in
[rootxjh gpio23]# 五、使用gpiolib完成led驱动 1、流程分析 第1步使用gpio_request申请要使用的一个GPIO。 第2步使用gpio_direction_input、gpio_direction_output 来设置输入、输出模式。 第3步使用gpio_set_value设置输出值或者使用gpio_get_value获取IO口值。 2、代码实践 Linux中查看gpio使用情况的方法 内核中提供了虚拟文件系统debugfs里面有一个gpio文件提供了gpio的使用信息比如谁被使用了谁没有被使用。 使用方法 1使用命令“mount -t debugfs debugfs /tmp”进行挂载 2之后使用“cat /tmp/gpio”即可得到gpio的所有信息 3使用完后“umount /tmp”卸载掉debugfs。 [rootxjh ]# cd tmp/
[rootxjh tmp]# ls
[rootxjh tmp]# mount -t debugfs debugfs /tmp
[rootxjh tmp]# ls
[rootxjh tmp]# cd ..
[rootxjh ]# ls
bin etc lib mnt root sys usr
dev home linuxrc proc sbin tmp var
[rootxjh ]# cd tmp/
[rootxjh tmp]# ls
apanic binder ieee80211 mmc2 pmstats
asoc gpio mmc0 mmc3 sched_features
bdi hid mmc1 pmem_gpu1 usb
[rootxjh tmp]# cat gpio
GPIOs 0-7, GPA0:GPIOs 9-12, GPA1:GPIOs 14-21, GPB:GPIOs 23-27, GPC0:gpio-23 (sysfs ) in loGPIOs 29-33, GPC1:GPIOs 35-38, GPD0:GPIOs 40-45, GPD1:GPIOs 47-54, GPE0:GPIOs 56-60, GPE1:GPIOs 62-69, GPF0:GPIOs 71-78, GPF1:GPIOs 80-87, GPF2:GPIOs 89-94, GPF3:GPIOs 96-102, GPG0:GPIOs 104-110, GPG1:GPIOs 112-118, GPG2:GPIOs 120-126, GPG3:GPIOs 128-135, GPH0:gpio-129 (GPH0 ) in higpio-130 (GPH0 ) in higpio-131 (GPH0 ) in hiGPIOs 137-144, GPH1:gpio-139 (GPH1 ) in lo irq-42 level-highGPIOs 146-153, GPH2:gpio-146 (GPH2 ) in higpio-147 (GPH1 ) in higpio-148 (GPH2 ) in higpio-149 (GPH2 ) in higpio-152 (GPH2 ) in logpio-153 (GPH3 ) in hiGPIOs 155-162, GPH3:GPIOs 164-170, GPI:GPIOs 172-179, GPJ0:GPIOs 181-186, GPJ1:GPIOs 188-195, GPJ2:GPIOs 197-204, GPJ3:GPIOs 206-210, GPJ4:GPIOs 212-219, MP01:GPIOs 221-224, MP02:GPIOs 226-233, MP03:GPIOs 235-242, MP04:GPIOs 244-251, MP05:GPIOs 253-260, MP06:GPIOs 262-269, MP07:GPIOs 271-278, MP10:GPIOs 280-287, MP11:GPIOs 289-296, MP12:GPIOs 298-305, MP13:GPIOs 307-314, MP14:GPIOs 316-323, MP15:GPIOs 325-332, MP16:GPIOs 334-341, MP17:GPIOs 343-349, MP18:GPIOs 351-358, MP20:GPIOs 360-367, MP21:GPIOs 369-376, MP22:GPIOs 378-385, MP23:GPIOs 387-394, MP24:GPIOs 396-403, MP25:GPIOs 405-412, MP26:GPIOs 414-421, MP27:GPIOs 423-429, MP28:GPIOs 431-436, ETC0:GPIOs 438-445, ETC1:GPIOs 447-454, ETC2:GPIOs 456-461, ETC4:
[rootxjh tmp]# 代码该驱动只申请了LED1资源 #include linux/module.h // module_init module_exit
#include linux/init.h // __init __exit
#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#define GPIO_LED1 S5PV210_GPJ0(3)
#define GPIO_LED2 S5PV210_GPJ0(4)
#define GPIO_LED3 S5PV210_GPJ0(5)#define X210_LED_OFF 1 // X210中LED是正极接电源负极节GPIO
#define X210_LED_ON 0 // 所以1是灭0是亮static struct led_classdev mydev1; // 定义结构体变量
static struct led_classdev mydev2; // 定义结构体变量
static struct led_classdev mydev3; // 定义结构体变量// 这个函数就是要去完成具体的硬件读写任务的
static void s5pv210_led1_set(struct led_classdev *led_cdev,enum led_brightness value)
{printk(KERN_INFO s5pv210_led1_set\n);//writel(0x11111111, GPJ0CON);// 在这里根据用户设置的值来操作硬件// 用户设置的值就是valueif (value LED_OFF){// 用户给了个0希望LED灭//writel(0x11111111, GPJ0CON);// 读改写三部曲//writel((readl(GPJ0DAT) | (13)), GPJ0DAT);gpio_set_value(GPIO_LED1, X210_LED_OFF);}else{// 用户给的是非0希望LED亮//writel(0x11111111, GPJ0CON);//writel((readl(GPJ0DAT) ~(13)), GPJ0DAT);gpio_set_value(GPIO_LED1, X210_LED_ON);}
}static void s5pv210_led2_set(struct led_classdev *led_cdev,enum led_brightness value)
{printk(KERN_INFO s5pv2102_led_set\n);//writel(0x11111111, GPJ0CON);// 在这里根据用户设置的值来操作硬件// 用户设置的值就是valueif (value LED_OFF){// 用户给了个0希望LED灭//writel(0x11111111, GPJ0CON);// 读改写三部曲//writel((readl(GPJ0DAT) | (14)), GPJ0DAT);}else{// 用户给的是非0希望LED亮//writel(0x11111111, GPJ0CON);//writel((readl(GPJ0DAT) ~(14)), GPJ0DAT);}
}static void s5pv210_led3_set(struct led_classdev *led_cdev,enum led_brightness value)
{printk(KERN_INFO s5pv210_led3_set\n);//writel(0x11111111, GPJ0CON);// 在这里根据用户设置的值来操作硬件// 用户设置的值就是valueif (value LED_OFF){// 用户给了个0希望LED灭//writel(0x11111111, GPJ0CON);// 读改写三部曲//writel((readl(GPJ0DAT) | (15)), GPJ0DAT);}else{// 用户给的是非0希望LED亮//writel(0x11111111, GPJ0CON);//writel((readl(GPJ0DAT) ~(15)), GPJ0DAT);}
}static int __init s5pv210_led_init(void)
{// 用户insmod安装驱动模块时会调用该函数// 该函数的主要任务就是去使用led驱动框架提供的设备注册函数来注册一个设备int ret -1;// 在这里去申请驱动用到的各种资源当前驱动中就是GPIO资源if (gpio_request(GPIO_LED1, led1_gpj0.3)) //这里是申请失败{printk(KERN_ERR gpio_request failed\n);} else //申请成功后{// 设置为输出模式并且默认输出1让LED灯灭gpio_direction_output(GPIO_LED1, 1);}// led1mydev1.name led1;mydev1.brightness 0; mydev1.brightness_set s5pv210_led1_set;ret led_classdev_register(NULL, mydev1);if (ret 0) {printk(KERN_ERR led_classdev_register failed\n);return ret;}// led2mydev2.name led2;mydev2.brightness 0; mydev2.brightness_set s5pv210_led2_set;ret led_classdev_register(NULL, mydev2);if (ret 0) {printk(KERN_ERR led_classdev_register failed\n);return ret;}// led3mydev3.name led3;mydev3.brightness 0; mydev3.brightness_set s5pv210_led3_set;ret led_classdev_register(NULL, mydev3);if (ret 0) {printk(KERN_ERR led_classdev_register failed\n);return ret;}return 0;
}static void __exit s5pv210_led_exit(void)
{led_classdev_unregister(mydev1);led_classdev_unregister(mydev2);led_classdev_unregister(mydev3);gpio_free(GPIO_LED1);
}module_init(s5pv210_led_init);
module_exit(s5pv210_led_exit);// MODULE_xxx这种宏作用是用来添加模块描述信息
MODULE_LICENSE(GPL); // 描述模块的许可证
MODULE_AUTHOR(aston 1264671872qq.com); // 描述模块的作者
MODULE_DESCRIPTION(s5pv210 led driver); // 描述模块的介绍信息
MODULE_ALIAS(s5pv210_led); // 描述模块的别名信息
