/***********************************************************************************

 *                      Linux driver 板级文件跟踪一般方法

 *  声明：

 *      1. 这是本人使用vim+ctags最常用的跟踪方法，也是唯一的方法；  :)

 *      2. 本人已经在跟踪线上标注了跟踪序号，也就是先后循序；

 *      3. 就目前而言，这种方法貌似是通用的；

 *      4. 这个例子仅仅是简单的演示，并没有全部展开，如果想要进一步跟踪，

 *          继续跟就行了。

 *      5. 源代码来自：myzr_android4_2_2_1_1_0.tar.bz2

 *

 *                                    2015-6-12 晴 深圳 南山平山村 曾剑锋

 **********************************************************************************/

cat arch/arm/mach-mx6/board-mx6q_sabresd.c

......

#define SABRESD_POWER_OFF   IMX_GPIO_NR(3, 29)          <--------------------------+

......                                                                             |

                                                                                   |

#if defined(CONFIG_KEYBOARD_GPIO) || defined(CONFIG_KEYBOARD_GPIO_MODULE)          |

#define GPIO_BUTTON(gpio_num, ev_code, act_low, descr, wake, debounce)  \ <------+ |

{                               \                                                | |

    .gpio       = gpio_num,             \                                        | |

    .type       = EV_KEY,               \                                        | |

    .code       = ev_code,              \                                        | |

    .active_low = act_low,              \                                        | |

    .desc       = "btn " descr,             \                                    | |

    .wakeup     = wake,                 \                                        ^ |

    .debounce_interval = debounce,              \                                | |

}                                                                                | |

                                                                                 | |

static struct gpio_keys_button new_sabresd_buttons[] = {        <-----<-------+  | |

    //GPIO_BUTTON(SABRESD_VOLUME_UP, KEY_VOLUMEUP, 1, "volume-up", 0, 1),     |  | |

    //GPIO_BUTTON(SABRESD_VOLUME_DN, KEY_VOLUMEDOWN, 1, "volume-down", 0, 1), |  | |

    GPIO_BUTTON(SABRESD_POWER_OFF, KEY_POWER, , "power-key", , ), --->----*--+ |

};                    ^------------------------------------------------------*----+

                                                                              |

static struct gpio_keys_platform_data new_sabresd_button_data = {  <-------+  |

    .buttons    = new_sabresd_buttons,       >------------>---------------*--+

    .nbuttons   = ARRAY_SIZE(new_sabresd_buttons),                         |

};                                                                         |

                                                                           |

static struct platform_device sabresd_button_device = { <--+               |

    .name           = "gpio-keys",                         |               |

    .id             = -,                                  |               ^

    .num_resources  = ,                                   |               |

};                                                         |               |

                                                           |               |

static void __init imx6q_add_device_buttons(void)    <-----*-------+       |

{                                                          |       |       |

    platform_device_add_data(&sabresd_button_device,  >---+       |       |

                &new_sabresd_button_data,                          |       |

                sizeof(new_sabresd_button_data));   >-------------*-------+

                                                                   |

    platform_device_register(&sabresd_button_device);              |

}                                                                  |

                                                                   |

                                                                   |

......                                                             ^

/*!                                                                |

 * Board specific initialization.                                  |

 */                                                                |

static void __init mx6_sabresd_board_init(void)   <------------<---*--------<-----+

{                                                                  |              |

    ......                                                         |              |

    imx6q_add_device_buttons(); ------>------------->-------------+              |

    ......                                                                        |

}                                                                                 |

                                                                                  |

......                                                                            |

/*                                                                                ^

 * initialize __mach_desc_MX6Q_SABRESD data structure.                            |

 */                                                                               |

MACHINE_START(MX6Q_SABRESD, "Freescale i.MX 6Quad/DualLite/Solo Sabre-SD Board")  |

    /* Maintainer: Freescale Semiconductor, Inc. */                               |

    .boot_params = MX6_PHYS_OFFSET + 0x100,                                       |

    .fixup = fixup_mxc_board,                                                     |

    .map_io = mx6_map_io,                                                         |

    .init_irq = mx6_init_irq,                                                     |

    .init_machine = mx6_sabresd_board_init,  ----->------------->------->--------+

    .timer = &mx6_sabresd_timer,

    .reserve = mx6q_sabresd_reserve,

MACHINE_END