嵌入式

使用class_attribute 生sys文件系统下生成调试文件，方便使用adb调试

2019-07-12 23:35发布

站内文章 / 嵌入式Linux
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/* * och177.c - Linux kernel modules for ambient light sensor * * Copyright (C) 2011 * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ #include #include #include #include #include #include #include #include #include #include #include #include #include static struct class *dunk_1_gpio_test_class=NULL; static ssize_t dunk_1_gnss_set_high(struct class *cls, struct class_attribute *attr, const char *_buf, size_t _count) { int gpio=0; sscanf(_buf, "%d", &gpio); printk("%s: gpio: %d ", __FUNCTION__, gpio); gpio_direction_output(gpio, 1); return _count; } static ssize_t dunk_1_gnss_set_low(struct class *cls, struct class_attribute *attr, const char *_buf, size_t _count) { int gpio=0; sscanf(_buf, "%d", &gpio); printk("%s: gpio: %d ", __FUNCTION__, gpio); gpio_direction_output(gpio, 0); return _count; } //这里可以去看一下class_attribute这个结构体，这个结构体对理解这个声明有用 static struct class_attribute dunk_1_gpio_test_attr[] = { __ATTR(output_high,0666, NULL, dunk_1_gnss_set_high), __ATTR(output_low,0666, NULL, dunk_1_gnss_set_low), __ATTR_NULL, }; static int __init dunk_1_gpio_test_init(void) { int ret; int i = 0; printk("%s start ", __FUNCTION__); //用class_create在sys/class/下面生成sys文件系统 dunk_1_gpio_test_class=class_create(THIS_MODULE,"dunk_1_gpioex_test"); if(IS_ERR(dunk_1_gpio_test_class)) { printk("create dunk_1_gnss fail "); return PTR_ERR(dunk_1_gpio_test_class);; } for (i = 0 ; NULL != attr_name(dunk_1_test_attr[i]);i++) { ret = class_create_file(dunk_1_gpio_test_class, &dunk_1_gpio_test_attr[i]); if (0 != ret) { printk("creat %s class file fail ",attr_name(dunk_1_gpio_test_attr[i])); break; } } printk("%s end ", __FUNCTION__); return 0; } static void __exit dunk_1_gpio_test_exit(void) { int i = 0; printk("dunk_1 gnss module cleanup start. "); for (i = 0 ; NULL != attr_name(dunk_1_gpio_test_attr[i]);i++) { class_remove_file(dunk_1_gpio_test_class, &dunk_1_gpio_test_attr[i]); } class_destroy(dunk_1_gpio_test_class); printk("dunk_1 gnss module cleanup OK! "); } MODULE_AUTHOR("dunk_1 "); MODULE_DESCRIPTION("dunk_1gpio test MODULE"); MODULE_LICENSE("GPL"); MODULE_VERSION("ver0.1"); module_init(dunk_1_gpio_test_init); module_exit(gota_gpio_test_exit);

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