【百度大脑AI计算盒FZ5C】firmware power 驱动代码分析

robe.zhang

【百度大脑AI计算盒FZ5C】firmware power 驱动代码分析

# 设备树

1. zynqmp_power: zynqmp-power {
   
2.     u-boot,dm-pre-reloc;
   
3.     compatible = "xlnx,zynqmp-power";
   
4.     interrupt-parent = <&gic>;
   
5.     interrupts = <0 35 4>;
   
6.     mboxes = <&ipi_mailbox_pmu1 0>,
   
7.          <&ipi_mailbox_pmu1 1>;
   
8.     mbox-names = "tx", "rx";
   
9. };

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# match table

1. static const struct of_device_id pm_of_match[] = {
   
2.     { .compatible = "xlnx,zynqmp-power", },
   
3.     { /* end of table */ },
   
4. };
   
5. MODULE_DEVICE_TABLE(of, pm_of_match);
   

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# driver

1. static struct platform_driver zynqmp_pm_platform_driver = {
   
2.     .probe = zynqmp_pm_probe,
   
3.     .remove = zynqmp_pm_remove,
   
4.     .driver = {
   
5.         .name = "zynqmp_power",
   
6.         .of_match_table = pm_of_match,
   
7.     },
   
8. };
   
9. module_platform_driver(zynqmp_pm_platform_driver);
   

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# probe：调用了 eemi_ops 的两个方法，创建工作堆列，用到了 mailbox，收到 mailbox 消息添加工作队列，回复消息

1. static int zynqmp_pm_probe(struct platform_device *pdev)
   
2. {
   
3.     int ret, irq;
   
4.     u32 pm_api_version;
   
5.     struct mbox_client *client;
   
6. 
   
7.     eemi_ops = zynqmp_pm_get_eemi_ops();
   
8.     if (IS_ERR(eemi_ops))
   
9.         return PTR_ERR(eemi_ops);
   
10. 
    
11.     if (!eemi_ops->get_api_version || !eemi_ops->init_finalize)
    
12.         return -ENXIO;
    
13. 
    
14.     eemi_ops->init_finalize();
    
15.     eemi_ops->get_api_version(&pm_api_version);
    
16. 
    
17.     /* Check PM API version number */
    
18.     if (pm_api_version < ZYNQMP_PM_VERSION)
    
19.         return -ENODEV;
    
20. 
    
21.     if (of_find_property(pdev->dev.of_node, "mboxes", NULL)) {
    
22.         zynqmp_pm_init_suspend_work =
    
23.             devm_kzalloc(&pdev->dev,
    
24.                      sizeof(struct zynqmp_pm_work_struct),
    
25.                      GFP_KERNEL);
    
26.         if (!zynqmp_pm_init_suspend_work)
    
27.             return -ENOMEM;
    
28. 
    
29.         INIT_WORK(&zynqmp_pm_init_suspend_work->callback_work,
    
30.               zynqmp_pm_init_suspend_work_fn);
    
31.         client = devm_kzalloc(&pdev->dev, sizeof(*client), GFP_KERNEL);
    
32.         if (!client)
    
33.             return -ENOMEM;
    
34. 
    
35.         client->dev = &pdev->dev;
    
36.         client->rx_callback = ipi_receive_callback;
    
37. 
    
38.         rx_chan = mbox_request_channel_byname(client, "rx");
    
39.         if (IS_ERR(rx_chan)) {
    
40.             dev_err(&pdev->dev, "Failed to request rx channel\n");
    
41.             return IS_ERR(rx_chan);
    
42.         }
    
43.     } else if (of_find_property(pdev->dev.of_node, "interrupts", NULL)) {
    
44.         irq = platform_get_irq(pdev, 0);
    
45.         if (irq <= 0)
    
46.             return -ENXIO;
    
47. 
    
48.         ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
    
49.                         zynqmp_pm_isr,
    
50.                         IRQF_NO_SUSPEND | IRQF_ONESHOT,
    
51.                         dev_name(&pdev->dev),
    
52.                         &pdev->dev);
    
53.         if (ret) {
    
54.             dev_err(&pdev->dev, "devm_request_threaded_irq '%d' "
    
55.                         "failed with %d\n", irq, ret);
    
56.             return ret;
    
57.         }
    
58.     } else {
    
59.         dev_err(&pdev->dev, "Required property not found in DT node\n");
    
60.         return -ENOENT;
    
61.     }
    
62. 
    
63.     ret = sysfs_create_file(&pdev->dev.kobj, &dev_attr_suspend_mode.attr);
    
64.     if (ret) {
    
65.         dev_err(&pdev->dev, "unable to create sysfs interface\n");
    
66.         return ret;
    
67.     }
    
68. 
    
69.     return 0;
    
70. }

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# 总结：仅初始化，确认版本，调用了 firmware 驱动
# power 是自己实现的功能，通过 mailbox 传递消息，通过工作队列调整电源状态。更深层面是不是继续调用 firmware 方法，暂时未知