【嵌入式Linux】Jetson nano GPIO应用 | 驱动开发 | 官方gpiolib、设备树与chip_driver

GPIO子系统

0.暴露给应用层

应用

$ echo 79 > /sys/class/gpio/export   //导出79号gpio 引脚，使得可在应用层访问
$ echo out > /sys/class/gpio/gpio79/direction  //设置 为输出
$ echo 1 > /sys/class/gpio/gpio79/value //输出高电平 开灯
$ echo 0 > /sys/class/gpio/gpio79/value  //输出低电平， 关灯	
$ cat /sys/kernel/debug/gpio  //查询gpio状态(问题：发现找不到gpio文件)
$ echo 79 > unexport //取消导出（发现gpio79消失了)

解决调试目录为空的问题

原因 //debug需要的文件系统 debugfs没有挂载
在 /etc/fstab	 的后面添加一行
debugfs     /sys/kernel/debug   debugfs  defaults         0       0

调试信息

$ cat /sys/kernel/debug/gpio  //查看gpio 当前配置情况（驱动暴露的调试信息）
$ cat  /sys/kernel/debug/tegra_gpio  //查看GPIO 寄存器内容(和芯片手册进行对应)
$ cat  /sys/kernel/debug/tegra_pinctrl_reg   //查看 pinctrl 寄存器内容	

1.最简读写文件(在/SYS下)

设备树

   sys_rw_led{  //对应生成 /sys/devices/sys_rw_led/led_gpiocompatible = "sys_rw_led";led_gpio  = <&gpio TEGRA_GPIO(J,7) GPIO_ACTIVE_HIGH>;};

验证测试

$ cd sys_rw_led
$ make
$ cp led.ko /nfs/rootfs$ cd ~/kernel-4.9
$ make dtbs
$ cp arch/arm64/boot/dts/tegra210-p3448-0000-p3449-0000-b00.dtb   /tftpboot/	重启板子
$ insmod led.ko
$ cd /sys/devices/sys_rw_led
$ echo 0 > led_gpio  //关灯
$ echo 1 > led_gpio  //亮灯

编译文件

//Makefile
ifeq ($(KERNELRELEASE),)
KERNELDIR ?= ~/kernel-4.9 
PWD := $(shell pwd)all:$(MAKE) -C $(KERNELDIR) M=$(PWD) modulesclean:rm -rf *.o *~ core .depend .*.cmd *.ko *.mod.c .tmp_versions Module* modules* a.out *.bakelseobj-m := led.o
endif	

驱动

• of_get_named_gpio_flags//获取设备树节点的属性gpio_is_valid//判断是否合法devm_gpio_request//申请使用gpio，并调用设置pinctrl

• device_create_file //根据设备树节点属性，创建相应的属性文件 /sys/devices/sys_rw_led/led_gpio

  • static struct device_attribute dev_attr_file //属性文件的描述

//led.c
#include <linux/init.h>                        
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/err.h>#include <linux/of_gpio.h>
#include <linux/gpio.h>#include <linux/platform_device.h>
#include <asm/io.h>#include <dt-bindings/gpio/gpio.h>#ifdef CONFIG_OF
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_gpio.h>
#endifint  led_gpio;
static ssize_t led_store(struct device *dev, struct device_attribute *attr,const char *buf, size_t count) {//写文件,控制 gpio 输出 （ echo 1 >   led_gpio)                if (buf[0] == '0') {gpio_direction_output(led_gpio, 0);}else if (buf[0] == '1') {gpio_direction_output(led_gpio, 1);}    printk(KERN_ERR "led_gpio_store %c \\n",buf[0]);   return count;
}ssize_t led_show(struct device *dev, struct device_attribute *attr,char *buf){  printk("led_show go \\n");	return 0;
}
//属性文件的描述
static struct device_attribute dev_attr_file = {    .attr = {        .name = "led_gpio",        .mode = (S_IRUGO | S_IWUSR)  },   .store = led_store, //echo 1> 就调用到这里了.show = led_show,  //cat led_gpio时调用，如果无需读的功能，可设为NULL,  且删除前面的S_IRUGO
};int leds_probe(struct platform_device *pdev)
{int  ret = 0;enum of_gpio_flags flags;//获取设备树节点的属性 "led_gpio"led_gpio = of_get_named_gpio_flags(pdev->dev.of_node, "led_gpio", 0, &flags);if (gpio_is_valid(led_gpio)) //判断是否合法{ret = devm_gpio_request(&pdev->dev,led_gpio, "led_gpio"); //申请使用gpio(如果被占用，将申请失败)if (ret) {printk("Failed to get led_gpio gpio.\\n");return -1;} }//根据设备树节点属性，创建相应的属性文件 /sys/devices/sys_rw_led/led_gpiodevice_create_file(&pdev->dev, &dev_attr_file);  // /device_create_file 里面是调用了 sysfs_create_fileprintk("leds_probe 1 ok\\n");return 0;
}int leds_remove(struct platform_device *pdev)
{   device_remove_file(&pdev->dev, &dev_attr_file);printk("leds_remove  ok\\n");    return 0;
}static const struct of_device_id of_led_match[] = {{ .compatible = "sys_rw_led", },{},
};MODULE_DEVICE_TABLE(of, of_led_match);struct platform_driver leds_drv = {.driver = {.owner = THIS_MODULE,.name = "sys_rw_led driver" ,.of_match_table = of_led_match,},.probe = leds_probe,.remove = leds_remove,    
};
module_platform_driver(leds_drv);
MODULE_LICENSE("GPL");

2.读写多个属性文件（在SYS下）

设备树

sys_rw_gpio{compatible = "bbcen,sys_rw_gpio";led_gpio  = <&gpio TEGRA_GPIO(J,7) GPIO_ACTIVE_HIGH>;     //40pin 丝印 12smoke_sensor_gpio = <&gpio TEGRA_GPIO(S,5) GPIO_ACTIVE_HIGH>; //40pin 丝印 29
};

验证测试

$ cd sys_read_write
$ make
$ cp gpio.ko /nfs/rootfs$ cd ~/kernel-4.9
$ make dtbs
$ cp arch/arm64/boot/dts/tegra210-p3448-0000-p3449-0000-b00.dtb   /tftpboot/	重启板子
$ insmod gpio.ko
$ cd /sys/devices/sys_rw_gpio
$ echo 0 > led_gpio  //关灯
$ echo 1 > led_gpio  //亮灯	
$ cat smoke_sensor_gpio  //读管脚输入电平，默认读到0，用杜邦线，把它接到前面亮灯的管脚时，能成功读到1

编译文件

ifeq ($(KERNELRELEASE),)
KERNELDIR ?= ~/kernel-4.9 
PWD := $(shell pwd)all:$(MAKE) -C $(KERNELDIR) M=$(PWD) modulesclean:rm -rf *.o *~ core .depend .*.cmd *.ko *.mod.c .tmp_versions Module* modules* a.out *.bakelseobj-m := gpio.o
endif	

驱动

• 定义一个结构体指针，分配空间，指定内容

• device_attribute gpio_attr[]

• sysfs_create_file //for循环读取，和上面的数组配合实现读多个属性

#include <linux/init.h>                        
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/slab.h>#include <linux/delay.h>
#include <linux/err.h>#include <linux/of_gpio.h>
#include <linux/gpio.h>#include <linux/platform_device.h>
#include <asm/irq.h>
#include <asm/io.h>#include <linux/delay.h>#include <dt-bindings/gpio/gpio.h>#ifdef CONFIG_OF
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_gpio.h>
#endifstruct gpio_dev{struct platform_device *pdev;int led_gpio;        int led_gpio_direction;	 int smoke_sensor_gpio;
};static struct gpio_dev *gpio_dev = NULL;static ssize_t led_gpio_store(struct device *dev, struct device_attribute *attr,const char *buf, size_t count) {//写文件,控制 gpio 输出 （ echo 1 >   led_gpio)        struct gpio_dev *pdata = gpio_dev;            if (buf[0] == '0') {pdata->led_gpio_direction = 0;gpio_direction_output(pdata->led_gpio, pdata->led_gpio_direction);}else if (buf[0] == '1') {pdata->led_gpio_direction = 1;gpio_direction_output(pdata->led_gpio, pdata->led_gpio_direction);}    printk(KERN_ERR "led_gpio_store %d \\n",pdata->led_gpio_direction);   return count;
}static ssize_t smoke_sensor_gpio_show(struct device *dev, struct device_attribute *attr, char *buf) {struct gpio_dev *pdata = gpio_dev; int gpio_value = 0;gpio_value = gpio_get_value(pdata->smoke_sensor_gpio); //获取 gpio的输入值（cat  smoke_sensor_gpio 时会触发）return snprintf(buf, PAGE_SIZE, "%d\\n",gpio_value);
}static struct device_attribute gpio_attr[] = {  __ATTR(led_gpio, 0664, NULL, led_gpio_store), //写：关联属性文件的写回调函数(*store)  echo时触发__ATTR(smoke_sensor_gpio, 0664, smoke_sensor_gpio_show,NULL), //读：关联属性文件的读回调函数(*show) cat 时触发
};static int  gpio_init_sysfs(struct device *dev)
{int i, ret;for (i = 0; i < ARRAY_SIZE(gpio_attr); i++) {ret = sysfs_create_file(&dev->kobj,  //创建设备的属性文件&gpio_attr[i].attr);if (ret){dev_err(dev, "create charger node(%s) error\\n",gpio_attr[i].attr.name);return -1;}}return 0;
}static int gpio_dt(struct gpio_dev *pdata) {int gpio;int ret;enum of_gpio_flags flags;struct device *dev = &pdata->pdev->dev;struct device_node *node = dev->of_node;gpio = of_get_named_gpio_flags(node, "led_gpio", 0, &flags);if (gpio_is_valid(gpio)){pdata->led_gpio           = gpio;pdata->led_gpio_direction = (flags == GPIO_ACTIVE_HIGH)? 1:0;	    printk(KERN_ERR"led_gpio: %d\\n", pdata->led_gpio);ret = devm_gpio_request(dev,gpio, "led_gpio");if (ret) {printk("Failed to get led_gpio gpio.\\n");return -1;}}gpio = of_get_named_gpio_flags(node, "smoke_sensor_gpio", 0, &flags);if (gpio_is_valid(gpio)){pdata->smoke_sensor_gpio        = gpio;printk(KERN_ERR"smoke_sensor_gpio: %d\\n", pdata->smoke_sensor_gpio);ret = devm_gpio_request(dev,gpio, "smoke_sensor_gpio");if (ret) {printk("Failed to get smoke_sensor_gpio gpio.\\n");return -1;}ret = gpio_direction_input(gpio);if (ret) {printk("Failed to set flame_sensor_gpio gpio.\\n");return -1;}}return 0;
}static void gpio_set_default(struct gpio_dev *pdata) {if (pdata->led_gpio) {gpio_direction_output(pdata->led_gpio, pdata->led_gpio_direction);}
}static int gpio_probe(struct platform_device *pdev) {int ret=0;	printk(KERN_ALERT "%s \\n",__func__);      gpio_dev = kmalloc(sizeof(struct gpio_dev), GFP_KERNEL);if (gpio_dev == NULL) {printk(KERN_ERR"kmalloc struct gpio_dev err \\n");return -ENOMEM;}memset(gpio_dev, 0, sizeof(struct gpio_dev));gpio_dev->pdev = pdev;ret = gpio_dt(gpio_dev);if(ret<0){printk(KERN_ERR"gpio_dt err \\n");	return -1;}gpio_set_default(gpio_dev);ret = gpio_init_sysfs(&gpio_dev->pdev->dev);if(ret<0){printk(KERN_ERR"gpio_init_sysfs  err \\n");	return -1;}	     printk(KERN_ALERT "%s  ok !!\\n",__func__);return 0;
}static int  gpio_remove(struct platform_device *pdev){kfree(gpio_dev);return 0;
}static struct of_device_id gpio_of_match[] = {{ .compatible = "bbcen,sys_rw_gpio" },{ }
};static struct platform_driver gpio_driver = {.driver		= {.name		= "sys_rw_gpio driver ",.of_match_table	= of_match_ptr(gpio_of_match),},.probe		= gpio_probe,.remove         = gpio_remove,
};

3.点多个灯(官方示例)

帮助文档

官方有驱动文件了，只需要参考帮助文档改设备树，make menuconfig对应选配，就能用了

//Documentation/devicetree/bindings/leds/leds-gpio.txt

设备树

//tegra210-p3448-0000-p3449-0000-b00.dts
yhai-gpio-led { compatible = "gpio-leds"; led1 {label = "led1"; gpios = <&gpio TEGRA_GPIO(J,7) GPIO_ACTIVE_HIGH>;  //对应40pin 丝印 12脚  接第一个灯default-state = "off"; }; led2 { label = "led2"; gpios = <&gpio TEGRA_GPIO(Z,0) GPIO_ACTIVE_HIGH>;  //对应40pin 丝印 31脚  接第二个灯default-state = "off"; }; led3 { label = "led3"; gpios = <&gpio TEGRA_GPIO(S,5) GPIO_ACTIVE_HIGH>;  //对应40pin 丝印 29脚  接第三个灯default-state = "off"; }; 
};

官方驱动

//见drivers/leds/leds-gpio.c   static const struct of_device_id of_gpio_leds_match[] = { { .compatible = "gpio-leds", },{}, 
};static struct platform_driver gpio_led_driver = {.probe      = gpio_led_probe,.driver     = {.name   = "leds-gpio",.of_match_table = of_gpio_leds_match,},
};
module_platform_driver(gpio_led_driver);

内核配置

$ cd ~/kernel-4.9
$ make menuconfig Device Drivers ---> [*] LED Support ---> <*> LED Class Support <*> LED Support for GPIO connected LEDs

验证测试

$ make dtbs
$ cp arch/arm64/boot/dts/tegra210-p3448-0000-p3449-0000-b00.dtb   /tftpboot/	
重启板子
# cd /sys/class/leds/
# echo 1 > led1/brightness //点亮第一个灯
# echo 0 > led1/brightness //灭第一个灯
# echo 1 > led2/brightness //点亮第二个灯
# echo 0 > led2/brightness //灭第二个灯
# echo 1 > led3/brightness //点亮第三个灯
# echo 0 > led3/brightness //灭第三个灯	

4.GPIO库gpiolib（对上统一操作接口）

//源码 drivers/gpio/gpiolib.c:  gpio子系统的核心实现，对外提供驱动API接口
EXPORT_SYMBOL_GPL(gpiod_get);
EXPORT_SYMBOL_GPL(gpiod_direction_output);
EXPORT_SYMBOL_GPL(gpiod_set_value);

//源码 drivers/gpio/gpiolib-sysfs.c
int gpiod_export(struct gpio_desc *desc, bool direction_may_change)
{ device_create_with_groups(&gpio_class, &gdev->dev,MKDEV(0, 0), data, gpio_groups,ioname ? ioname : "gpio%u",  //创建 /sys/class/gpio/gpio79 文件夹desc_to_gpio(desc));
}static ssize_t export_store(struct class *class,struct class_attribute *attr,const char *buf, size_t len)
{gpio_to_desc(gpio);gpiod_request(desc, "sysfs");  //先申请（检测是否被占用)gpiod_export(desc, true); //导出 生成 /sys/class/gpio/gpio79 文件夹（包括direction  value等）
}static struct class_attribute gpio_class_attrs[] = {__ATTR(export, 0200, NULL, export_store), //写：关联属性文件的写回调函数(*store)   echo 79 > /sys/class/gpio/export 时触发__ATTR(unexport, 0200, NULL, unexport_store),__ATTR_NULL,
};static struct class gpio_class = {.name =     "gpio",.owner =    THIS_MODULE,.class_attrs =  gpio_class_attrs,
};int gpiochip_sysfs_register(struct gpio_device *gdev)
{//创建 /sys/class/gpio/gpiochip0 文件夹device_create_with_groups(&gpio_class, parent,MKDEV(0, 0),chip, gpiochip_groups,"gpiochip%d", chip->base);	
}static int __init gpiolib_sysfs_init(void)
{struct gpio_device *gdev;class_register(&gpio_class); //注册 生成 /sys/class/gpio 文件夹gpiochip_sysfs_register(gdev);
}postcore_initcall(gpiolib_sysfs_init); //声明 在内核启动时自动加载 

5.GPIO设备树

//帮助文档  Documentation/devicetree/bindings/gpio/nvidia,tegra186-gpio.txt//tegra210-soc-base.dtsi   cpu的基本配置
//位置: public_sources\\hardware\\nvidia\\soc\\t210\\kernel-dts\\tegra210-soc\\
gpio: gpio@6000d000 {//gpio子节点compatible = "nvidia,tegra210-gpio", "nvidia,tegra124-gpio", "nvidia,tegra30-gpio";reg = <0x0 0x6000d000 0x0 0x1000>; //前2个数表示起始地址(由父节点的#address-cells = <2> 决定)//后2个数表示长度范围(由父节点的#size-cells = <2> 决定)//域名(0:spi 1:ppi) + 中断索引(36) + 触发方式(高电平触发） Documentation/devicetree/bindings/interrupt-controller/arm,gic.txtinterrupts = <  0 32 0x04    //32: gpio编号  0x04:高电平触发中断 0 33 0x04  0 34 0x040 35 0x040 55 0x040 87 0x040 89 0x040 125 0x04>;status = "disabled";  //声明 本节点是禁用状态#gpio-cells = <2>;  //声明 引用本节点，用 gpios 属性传参时 参数占2个单位gpio-controller;  //声明本节点 是 GPIO 控制器 #interrupt-cells = <2>;interrupt-controller;  //声明本节点 是 中断 控制器 gpio-ranges = <&pinmux 0 0 246>;  //设置gpio number 与 pinctrl number的 映射，详见PinCtrl子系统};

6.GPIO芯片驱动gpio_chip_driver

( 由原厂开发)

//查看驱动信息
$ cat  /proc/devices  //查看内核加载的驱动设备254 gpiochip    
$ cat   /sys/class/gpio/gpiochip0/label //查看驱动设备的标签名tegra-gpio  //对应 gpio-tegra.c    的  tgi->gc.label   = "tegra-gpio";//源码 gpio-tegra.c  英伟达原厂开发的芯片驱动

定义类

//gpio-tegra.c	
struct tegra_gpio_info { //定义gpio类struct device               *dev;void __iomem                *regs;struct irq_domain           *irq_domain;struct tegra_gpio_bank          *bank_info;const struct tegra_gpio_soc_config  *soc;struct gpio_chip            gc; //gpio控制器 struct irq_chip             ic; //irq控制器u32                 bank_count;
};
static struct tegra_gpio_info *gpio_info; //定义 gpio对象static const struct of_device_id tegra_gpio_of_match[] = {               { .compatible = "nvidia,tegra210-gpio", .data = &tegra210_gpio_config },                                                           
};  static struct platform_driver tegra_gpio_driver = {                      .driver     = {                                                      .name   = "tegra-gpio",                                          .of_match_table = tegra_gpio_of_match,},.probe      = tegra_gpio_probe,                                      
};      static int __init tegra_gpio_init(void)                                  
{return platform_driver_register(&tegra_gpio_driver);                 
}
subsys_initcall(tegra_gpio_init);  //添加到内核启动列表中

构建对象（注册制）

• devm_kzalloc会自动释放资源，常用

static int tegra_gpio_probe(struct platform_device *pdev)
{struct tegra_gpio_info *tgi;  //定义对象//为对象分配空间tgi = devm_kzalloc(&pdev->dev, sizeof(*tgi), GFP_KERNEL);if (!tgi)return -ENODEV;gpio_info = tgi;//获取所有bank的中断资源for (;;) {res = platform_get_resource(pdev, IORESOURCE_IRQ,   //见设备树 interrupts =<  0 32 0x04 ...>tgi->bank_count);if (!res)break;tgi->bank_count++;}//初始化对象：里面的变量都赋值，指针都指向实体，tgi->gc.label           = "tegra-gpio";  //对应  /sys/class/gpio/gpiochip0/labeltgi->gc.request         = tegra_gpio_request; //申请gpio(如果被占用，将申请失败)tgi->gc.free            = tegra_gpio_free; //释放gpio(释放后，别的驱动才能申请)tgi->gc.direction_input     = tegra_gpio_direction_input; //tgi->gc.get         = tegra_gpio_get;tgi->gc.direction_output    = tegra_gpio_direction_output;//gpio 方向设为输出tgi->gc.set         = tegra_gpio_set;//获取MEM资源res = platform_get_resource(pdev, IORESOURCE_MEM, 0);  //见设备树 reg = <0x0 0x6000d000 0x0 0x1000>;tgi->regs = devm_ioremap_resource(&pdev->dev, res);if (IS_ERR(tgi->regs))return PTR_ERR(tgi->regs);	tegra_gpio_debuginit(tgi); //添加 调试功能
}	static inline void tegra_gpio_writel(struct tegra_gpio_info *tgi,u32 val, u32 reg)
{__raw_writel(val, tgi->regs + reg); /* 实现见  arch/arm64/include/asm/io.h用C语言中嵌入汇编方式   ,用str  汇编指令 实现写数据static inline void __raw_writel(u32 val, volatile void __iomem *addr){asm volatile("str %w0, [%1]" : : "rZ" (val), "r" (addr));}*/
}static void tegra_gpio_mask_write(struct tegra_gpio_info *tgi, u32 reg,int gpio, int value)
{tegra_gpio_writel(tgi, val, reg);
}static void tegra_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
{//通过 GPIO_MSK_OUT 宏 实现各gpio 地址间转换关系(如不同端口 偏移量)tegra_gpio_mask_write(tgi, GPIO_MSK_OUT(tgi, offset), offset, value);
}static int tegra_gpio_direction_output(struct gpio_chip *chip, unsigned offset,int value)
{struct tegra_gpio_info *tgi = gpiochip_get_data(chip);int ret;tegra_gpio_set(chip, offset, value);tegra_gpio_mask_write(tgi, GPIO_MSK_OE(tgi, offset), offset, 1);tegra_gpio_enable(tgi, offset);ret = pinctrl_gpio_direction_output(chip->base + offset); //向pinctrl子系统 申请管脚 设为gpio输出模式return ret;
}

支持SYS控制

#ifdef	CONFIG_DEBUG_FS  //当打开 内核调试关，才把调试源码编译进来#include <linux/debugfs.h>
#include <linux/seq_file.h>static int dbg_gpio_open(struct inode *inode, struct file *file)
{return single_open(file, dbg_gpio_show, inode->i_private);
}static const struct file_operations debug_fops = {.open		= dbg_gpio_open,.read		= seq_read,.llseek		= seq_lseek,.release	= single_release,
};static void tegra_gpio_debuginit(struct tegra_gpio_info *tgi)
{(void) debugfs_create_file("tegra_gpio", S_IRUGO,  //创建调试文件 NULL, tgi, &debug_fops);
}#elsestatic inline void tegra_gpio_debuginit(struct tegra_gpio_info *tgi)
{
}#endif

寄存器自适应(管脚变了，不用再该代码，只需该改备树)

#include <linux/gpio.h>  //for gpio_chip#define GPIO_BANK(x)        ((x) >> 5)
#define GPIO_PORT(x)        (((x) >> 3) & 0x3)
#define GPIO_BIT(x)     ((x) & 0x7)#define GPIO_REG(tgi, x)    (GPIO_BANK(x) * tgi->soc->bank_stride + \\GPIO_PORT(x) * 4)#define GPIO_CNF(t, x)      (GPIO_REG(t, x) + 0x00)
#define GPIO_OE(t, x)       (GPIO_REG(t, x) + 0x10)
#define GPIO_OUT(t, x)      (GPIO_REG(t, x) + 0X20)
#define GPIO_IN(t, x)       (GPIO_REG(t, x) + 0x30)
#define GPIO_INT_STA(t, x)  (GPIO_REG(t, x) + 0x40)
#define GPIO_INT_ENB(t, x)  (GPIO_REG(t, x) + 0x50)
#define GPIO_INT_LVL(t, x)  (GPIO_REG(t, x) + 0x60)
#define GPIO_INT_CLR(t, x)  (GPIO_REG(t, x) + 0x70)
#define GPIO_DBC_CNT(t, x)  (GPIO_REG(t, x) + 0xF0)#define GPIO_MSK_CNF(t, x)  (GPIO_REG(t, x) + t->soc->upper_offset + 0x00)
#define GPIO_MSK_OE(t, x)   (GPIO_REG(t, x) + t->soc->upper_offset + 0x10)
#define GPIO_MSK_OUT(t, x)  (GPIO_REG(t, x) + t->soc->upper_offset + 0X20)
#define GPIO_MSK_DBC_EN(t, x)   (GPIO_REG(t, x) + t->soc->upper_offset + 0x30)
#define GPIO_MSK_INT_STA(t, x)  (GPIO_REG(t, x) + t->soc->upper_offset + 0x40)
#define GPIO_MSK_INT_ENB(t, x)  (GPIO_REG(t, x) + t->soc->upper_offset + 0x50)
#define GPIO_MSK_INT_LVL(t, x)  (GPIO_REG(t, x) + t->soc->upper_offset + 0x60)#define GPIO_INT_LVL_MASK           0x010101
#define GPIO_INT_LVL_EDGE_RISING    0x000101
#define GPIO_INT_LVL_EDGE_FALLING   0x000100
#define GPIO_INT_LVL_EDGE_BOTH      0x010100
#define GPIO_INT_LVL_LEVEL_HIGH     0x000001
#define GPIO_INT_LVL_LEVEL_LOW      0x000000	struct tegra_gpio_soc_config {bool debounce_supported;u32 bank_stride;u32 upper_offset;
};static const struct tegra_gpio_soc_config tegra210_gpio_config = {.debounce_supported = true,.bank_stride = 0x100,.upper_offset = 0x80,
};static const struct of_device_id tegra_gpio_of_match[] = {{ .compatible = "nvidia,tegra210-gpio", .data = &tegra210_gpio_config },
}/*打印 各bank gpio 寄存器列表的值 -> 对应芯片手册里 #define GPIO3  	0x6000D200 // 第3个Bank GPIO 的基地址//---偏移量#define CNF		0x04  //配置寄存器 (0:GPIO  1:SFIO)#define OE   	0x14  //输出使能寄存器 (1:使能 0:关闭)#define OUT  	0x24  //输出寄存器（1：高电平 0：低电平）#define MSK_CNF 0x84  //配置屏蔽寄存器(高位1:屏蔽 高位0:不屏蔽   低位1:GPIO模式 低位0:SFIO模式)#define MSK_OE  0x94  //输出使能屏蔽寄存器(高位1:禁止写   低位1:使能)#define MSK_OUT 0xA4  //输出屏蔽寄存器(高位1:禁止写   低位1:高电平)
*/
static int dbg_gpio_show(struct seq_file *s, void *unused)
{struct tegra_gpio_info *tgi = s->private;int i;int j;char x, y;x = ' ';y = 'A';seq_printf(s, "Name:Bank:Port CNF OE OUT IN INT_STA INT_ENB INT_LVL\\n");for (i = 0; i < tgi->bank_count; i++) {for (j = 0; j < 4; j++) {int gpio = tegra_gpio_compose(i, j, 0);seq_printf(s,"%c%c: %d:%d %02x %02x %02x %02x %02x %02x %06x\\n",x, y, i, j,tegra_gpio_readl(tgi, GPIO_CNF(tgi, gpio)), //用GPIO_CNF 宏，实现各gpio 地址间转换关系(如不同端口 偏移量)tegra_gpio_readl(tgi, GPIO_OE(tgi, gpio)),tegra_gpio_readl(tgi, GPIO_OUT(tgi, gpio)),tegra_gpio_readl(tgi, GPIO_IN(tgi, gpio)),tegra_gpio_readl(tgi, GPIO_INT_STA(tgi, gpio)),tegra_gpio_readl(tgi, GPIO_INT_ENB(tgi, gpio)),tegra_gpio_readl(tgi, GPIO_INT_LVL(tgi, gpio)));if (x != ' ')x++;if (y == 'Z') {y = 'A';x = 'A';} else {y++;};}}return 0;
}