Re: [PATCH v3 7/7] rtc: Add Nuvoton NCT6694 RTC support

Alexandre Belloni
2024-12-16T10:42:07Z

On 10/12/2024 18:45:24+0800, Ming Yu wrote:
> +static int nct6694_rtc_probe(struct platform_device *pdev)
> +{
> + struct nct6694_rtc_data *data;
> + struct nct6694 *nct6694 = dev_get_drvdata(pdev->dev.parent);
> + int ret, irq;
> +
> + irq = irq_create_mapping(nct6694->domain, NCT6694_IRQ_RTC);
> + if (!irq)
> + return -EINVAL;
> +
> + data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
> + if (!data)
> + return -ENOMEM;
> +
> + data->xmit_buf = devm_kcalloc(&pdev->dev, NCT6694_MAX_PACKET_SZ,
> + sizeof(unsigned char), GFP_KERNEL);
> + if (!data->xmit_buf)
> + return -ENOMEM;
> +
> + data->rtc = devm_rtc_allocate_device(&pdev->dev);
> + if (IS_ERR(data->rtc))
> + return PTR_ERR(data->rtc);
> +
> + data->nct6694 = nct6694;
> + data->rtc->ops = &nct6694_rtc_ops;
> + data->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
> + data->rtc->range_max = RTC_TIMESTAMP_END_2099;
> +
> + mutex_init(&data->lock);

You should use rtc_lock/rtc_unlock instead of having your own lock. The
core will take and release the lock appropriately before calling the
rtc_ops so you only have to do it in the irq handler.

> +
> + device_set_wakeup_capable(&pdev->dev, 1);

This will cause a memory leak later on, see the discussion here:

https://lore.kernel.org/linux-rtc/a88475b6-08bf-4c7c-ad63-efd1f29307e3@pf.is.s.u-tokyo.ac.jp/T/#mf51fdce6036efa3ea12fe75bd5126d4ac0c6813e

> +
> + platform_set_drvdata(pdev, data);
> +
> + ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
> + nct6694_irq, IRQF_ONESHOT,
> + "nct6694-rtc", data);
> + if (ret < 0)
> + return dev_err_probe(&pdev->dev, ret, "Failed to request irq\n");
> +
> + /* Register rtc device to RTC framework */
> + return devm_rtc_register_device(data->rtc);
> +}
> +
> +static struct platform_driver nct6694_rtc_driver = {
> + .driver = {
> + .name = "nct6694-rtc",
> + },
> + .probe = nct6694_rtc_probe,
> +};
> +
> +module_platform_driver(nct6694_rtc_driver);
> +
> +MODULE_DESCRIPTION("USB-RTC driver for NCT6694");
> +MODULE_AUTHOR("Ming Yu <tmyu0@nuvoton.com>");
> +MODULE_LICENSE("GPL");
> +MODULE_ALIAS("platform:nct6694-rtc");
> --
> 2.34.1
>

--
Alexandre Belloni, co-owner and COO, Bootlin
Embedded Linux and Kernel engineering