Linux内核中ideapad-laptop.c文件全解析2

接前一篇文章《Linux内核中ideapad-laptop.c文件全解析1》，地址为：

Linux内核中ideapad-laptop.c文件全解析1_蓝天居士的博客-CSDN博客

上一回讲到了ideapad_acpi_driver。本文对于其成员进行详细解析。再列一下其源码：

static const struct acpi_device_id ideapad_device_ids[] = {
	{"VPC2004", 0},
	{"", 0},
};
MODULE_DEVICE_TABLE(acpi, ideapad_device_ids);
 
static struct platform_driver ideapad_acpi_driver = {
	.probe = ideapad_acpi_add,
	.remove = ideapad_acpi_remove,
	.driver = {
		.name   = "ideapad_acpi",
		.pm     = &ideapad_pm,
		.acpi_match_table = ACPI_PTR(ideapad_device_ids),
	},
};
 
module_platform_driver(ideapad_acpi_driver);

ideapad_device_ids数组也可以说是表的定义和初始化就在上边，它是用来匹配平台驱动和平台设备的。

probe探测函数对应的ideapad_acpi_add函数在同文件（drivers/platform/x86/ideapad-laptop.c）中实现，源码如下：

static int ideapad_acpi_add(struct platform_device *pdev)
{
	struct acpi_device *adev = ACPI_COMPANION(&pdev->dev);
	struct ideapad_private *priv;
	acpi_status status;
	unsigned long cfg;
	int err, i;
 
	if (!adev || eval_int(adev->handle, "_CFG", &cfg))
		return -ENODEV;
 
	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
	if (!priv)
		return -ENOMEM;
 
	dev_set_drvdata(&pdev->dev, priv);
 
	priv->cfg = cfg;
	priv->adev = adev;
	priv->platform_device = pdev;
 
	ideapad_check_features(priv);
 
	err = ideapad_sysfs_init(priv);
	if (err)
		return err;
 
	ideapad_debugfs_init(priv);
 
	err = ideapad_input_init(priv);
	if (err)
		goto input_failed;
 
	err = ideapad_kbd_bl_init(priv);
	if (err) {
		if (err != -ENODEV)
			dev_warn(&pdev->dev, "Could not set up keyboard backlight LED: %d\n", err);
		else
			dev_info(&pdev->dev, "Keyboard backlight control not available\n");
	}
 
	/*
	 * On some models without a hw-switch (the yoga 2 13 at least)
	 * VPCCMD_W_RF must be explicitly set to 1 for the wifi to work.
	 */
	if (!priv->features.hw_rfkill_switch)
		write_ec_cmd(priv->adev->handle, VPCCMD_W_RF, 1);
 
	/* The same for Touchpad */
	if (!priv->features.touchpad_ctrl_via_ec)
		write_ec_cmd(priv->adev->handle, VPCCMD_W_TOUCHPAD, 1);
 
	for (i = 0; i < IDEAPAD_RFKILL_DEV_NUM; i++)
		if (test_bit(ideapad_rfk_data[i].cfgbit, &priv->cfg))
			ideapad_register_rfkill(priv, i);
 
	ideapad_sync_rfk_state(priv);
	ideapad_sync_touchpad_state(priv);
 
	err = ideapad_dytc_profile_init(priv);
	if (err) {
		if (err != -ENODEV)
			dev_warn(&pdev->dev, "Could not set up DYTC interface: %d\n", err);
		else
			dev_info(&pdev->dev, "DYTC interface is not available\n");
	}
 
	if (acpi_video_get_backlight_type() == acpi_backlight_vendor) {
		err = ideapad_backlight_init(priv);
		if (err && err != -ENODEV)
			goto backlight_failed;
	}
 
	status = acpi_install_notify_handler(adev->handle,
					     ACPI_DEVICE_NOTIFY,
					     ideapad_acpi_notify, priv);
	if (ACPI_FAILURE(status)) {
		err = -EIO;
		goto notification_failed;
	}
 
#if IS_ENABLED(CONFIG_ACPI_WMI)
	for (i = 0; i < ARRAY_SIZE(ideapad_wmi_fnesc_events); i++) {
		status = wmi_install_notify_handler(ideapad_wmi_fnesc_events[i],
						    ideapad_wmi_notify, priv);
		if (ACPI_SUCCESS(status)) {
			priv->fnesc_guid = ideapad_wmi_fnesc_events[i];
			break;
		}
	}
 
	if (ACPI_FAILURE(status) && status != AE_NOT_EXIST) {
		err = -EIO;
		goto notification_failed_wmi;
	}
#endif
 
	return 0;
 
#if IS_ENABLED(CONFIG_ACPI_WMI)
notification_failed_wmi:
	acpi_remove_notify_handler(priv->adev->handle,
				   ACPI_DEVICE_NOTIFY,
				   ideapad_acpi_notify);
#endif
 
notification_failed:
	ideapad_backlight_exit(priv);
 
backlight_failed:
	ideapad_dytc_profile_exit(priv);
 
	for (i = 0; i < IDEAPAD_RFKILL_DEV_NUM; i++)
		ideapad_unregister_rfkill(priv, i);
 
	ideapad_kbd_bl_exit(priv);
	ideapad_input_exit(priv);
 
input_failed:
	ideapad_debugfs_exit(priv);
	ideapad_sysfs_exit(priv);
 
	return err;
}

remove移除函数对应的ideapad_acpi_remove函数也在同文件（drivers/platform/x86/ideapad-laptop.c）中实现，源码如下：

static int ideapad_acpi_remove(struct platform_device *pdev)
{
	struct ideapad_private *priv = dev_get_drvdata(&pdev->dev);
	int i;
 
#if IS_ENABLED(CONFIG_ACPI_WMI)
	if (priv->fnesc_guid)
		wmi_remove_notify_handler(priv->fnesc_guid);
#endif
 
	acpi_remove_notify_handler(priv->adev->handle,
				   ACPI_DEVICE_NOTIFY,
				   ideapad_acpi_notify);
 
	ideapad_backlight_exit(priv);
	ideapad_dytc_profile_exit(priv);
 
	for (i = 0; i < IDEAPAD_RFKILL_DEV_NUM; i++)
		ideapad_unregister_rfkill(priv, i);
 
	ideapad_kbd_bl_exit(priv);
	ideapad_input_exit(priv);
	ideapad_debugfs_exit(priv);
	ideapad_sysfs_exit(priv);
 
	return 0;
}

实际上通过ideapad_acpi_remove函数更容易看出ideapad_acpi_add函数完成的工作，包括了：

• sysfs初始化：ideapad_sysfs_init
• debugfs初始化：ideapad_debugfs_init
• 输入初始化：idea_input_init_init
• 键盘（按键）背光初始化：ideapad_kbd_bl_init
• 配置初始化：idea_dytc_profile_init
• 背光初始化：ideapad_backlight_init
• acpi通知处理：acpi_install_notify_handler
• wmi通知处理：wmi_install_notify_handler
• ……

欲知各个函数的具体实现细节，且听下回分解。