儿童影楼网站设计,四川省工程信息造价网,购买淘宝店铺在哪个平台,道路建设网站专题因为项目需要控制的GPIO口比较多#xff0c;如果每个GPIO口都写一个驱动就显得比骄麻烦#xff0c;所以就写了一个通用的GPIO口驱动。只要dts里面配置好设备GPIO相关信息就可以自动加载了。可以很充分的体现多个设备一个驱动的优良性。dts文件gpio_rs485: gpio_rs485 {status… 因为项目需要控制的GPIO口比较多如果每个GPIO口都写一个驱动就显得比骄麻烦所以就写了一个通用的GPIO口驱动。只要dts里面配置好设备GPIO相关信息就可以自动加载了。可以很充分的体现多个设备一个驱动的优良性。dts文件 gpio_rs485: gpio_rs485 {status okay;compatible gpio,px30-gpio;cname rs485;en-gpio gpio3 12 GPIO_ACTIVE_HIGH;};
驱动源代码#include dt-bindings/gpio/gpio.h
#include linux/gpio.h
#include linux/of_gpio.h
#include linux/module.h
#include linux/kernel.h
#include linux/init.h
#include linux/platform_device.h
#include linux/err.h
#include linux/slab.hstruct gpio_dev_data {int en_pin;int en_val;int gpio_val;
};static struct of_device_id gpio_of_match[] {{ .compatible gpio,px30-gpio },{ }
};MODULE_DEVICE_TABLE(of, gpio_of_match);static ssize_t gpio_store_en(struct device *dev,struct device_attribute *attr,const char *buf, size_t count)
{struct gpio_dev_data *dev_data dev_get_drvdata(dev);unsigned long value 0;int ret;/*将echo进来的buf转换成整型*/ret kstrtoul(buf, 16, value);if (ret 0) {printk( %s:kstrtoul failed, ret%d\n, __func__, ret);return ret;}printk(%s: en value : %d\n, __func__, (int)value);if (value) {gpio_direction_output(dev_data-en_pin, dev_data-en_val);dev_data-gpio_val 1;} else {gpio_direction_output(dev_data-en_pin, !dev_data-en_val);dev_data-gpio_val 0;}return count;
}static char mybuf[10]123;/*cat命令时,将会调用该函数*/
static ssize_t gpio_show_en(struct device *dev,struct device_attribute *attr, char *buf)
{struct gpio_dev_data *dev_data dev_get_drvdata(dev);snprintf(mybuf,sizeof(mybuf),%d,dev_data-gpio_val);return sprintf(buf, %s\n, mybuf);
}static DEVICE_ATTR(gpio_en, S_IWUSR, gpio_show_en, gpio_store_en);static int gpio_probe(struct platform_device *pdev)
{struct device_node *node pdev-dev.of_node;enum of_gpio_flags flags;int gpio;int ret;int en_value;struct class *dev_class;struct device *ctl_dev;struct gpio_dev_data *dev_data;int err;const char *class_name;printk(%s enter: %d\n, __func__, __LINE__);if (!node)return -ENODEV;/*获取gpio口*/gpio of_get_named_gpio_flags(node, en-gpio, 0, flags);en_value (flags GPIO_ACTIVE_HIGH) ? 1 : 0;if (!gpio_is_valid(gpio)) {dev_err(pdev-dev, invalid en gpio%d\n, gpio);}ret devm_gpio_request(pdev-dev, gpio, onoff);if (ret) {dev_err(pdev-dev,failed to request GPIO%d for \n,gpio);return -EINVAL;}/*设置probe的默认电平*/gpio_direction_output(gpio, !en_value);dev_data kzalloc(sizeof(struct gpio_dev_data), GFP_KERNEL);if (dev_data NULL) {printk(Failed to malloc gpio_dev_data\n);return -ENOMEM;}if(en_value 0)dev_data-gpio_val 0;elsedev_data-gpio_val 1;/*创建class节点*/err of_property_read_string(node, cname, class_name);if(err){printk(%s get class name error %d\n,__FUNCTION__,__LINE__);return -EINVAL;}dev_class class_create(THIS_MODULE, class_name);ctl_dev device_create(dev_class, NULL, 0, NULL, onoff);if (IS_ERR(ctl_dev)) {dev_err(ctl_dev, Failed to create device\n);ret PTR_ERR(ctl_dev);goto err_create_dev;}err device_create_file(ctl_dev, dev_attr_gpio_en);if (err)printk(driver_create_file %d\n, err);/*获取的gpio赋值全局变量*/dev_data-en_pin gpio;dev_data-en_val en_value;dev_info(ctl_dev, %s: %d\n, __func__, __LINE__);dev_info(pdev-dev, %s: %d\n, __func__, __LINE__);dev_set_drvdata(ctl_dev, dev_data);dev_set_drvdata(pdev-dev, dev_data);return 0;err_create_dev:kfree(dev_data);return ret;
}static int gpio_remove(struct platform_device *pdev)
{printk(%s: %d\n, __func__, __LINE__);return 0;
}#ifdef CONFIG_PM_SLEEP
static int gpio_suspend(struct device *dev)
{struct gpio_dev_data *dev_data dev_get_drvdata(dev);dev_info(dev, %s: %d\n, __func__, __LINE__);gpio_direction_output(dev_data-en_pin, !dev_data-en_val);return 0;
}static int gpio_resume(struct device *dev)
{printk(%s: %d\n, __func__, __LINE__);return 0;
}
#endifstatic const struct dev_pm_ops gpio_pm_ops {
#ifdef CONFIG_PM_SLEEP.suspend gpio_suspend,.resume gpio_resume,.poweroff gpio_suspend,.restore gpio_resume,
#endif
};static struct platform_driver gpio_driver {.driver {.name gpio-en,.owner THIS_MODULE,.pm gpio_pm_ops,.of_match_table of_match_ptr(gpio_of_match),},.probe gpio_probe,.remove gpio_remove,
};module_platform_driver(gpio_driver);MODULE_AUTHOR(Weiqifa 329410527qq.com);
MODULE_DESCRIPTION(simple gpio driver);
MODULE_LICENSE(GPL);Makefile文件obj-$(CONFIG_GPIO_CONTROL) gpio_control.o
Kconfigconfig GPIO_CONTROLtristate GPIO control driverdefault nhelpGPIO control driver. 回复「 篮球的大肚子」进入技术群聊回复「1024」获取1000G学习资料
