Hello,
On 01/08/2021 18:09:20+0200, Romain Perier wrote:
> +static int msc313_rtc_probe(struct platform_device *pdev)
> +{
> + struct device *dev = &pdev->dev;
> + struct msc313_rtc *priv;
> + int ret;
> + int irq;
> + unsigned long rate;
> + u16 reg;
> +
> + priv = devm_kzalloc(&pdev->dev, sizeof(struct msc313_rtc), GFP_KERNEL);
> + if (!priv)
> + return -ENOMEM;
> +
> + priv->rtc_base = devm_platform_ioremap_resource(pdev, 0);
> + if (IS_ERR(priv->rtc_base))
> + return PTR_ERR(priv->rtc_base);
> +
> + irq = platform_get_irq(pdev, 0);
> + if (irq < 0)
> + return -EINVAL;
> +
> + priv->rtc_dev = devm_rtc_allocate_device(dev);
> + if (IS_ERR(priv->rtc_dev))
> + return PTR_ERR(priv->rtc_dev);
> +
> + priv->rtc_dev->ops = &msc313_rtc_ops;
> + priv->rtc_dev->range_min = RTC_TIMESTAMP_BEGIN_0000;
I'm pretty sure this doesn't fit in this RTC registers, you should
probably leave range_min to 0 (i.e. not set it at all).
> + priv->rtc_dev->range_max = U32_MAX - 1; /* 2106-02-07 06:28:14 */
I guess this one should be U32_MAX
> +
> + ret = devm_request_irq(dev, irq, msc313_rtc_interrupt, IRQF_SHARED,
> + dev_name(&pdev->dev), &pdev->dev);
> + if (ret) {
> + dev_err(dev, "Could not request IRQ\n");
> + return ret;
> + }
> +
> + priv->clk = devm_clk_get(dev, NULL);
> + if (IS_ERR(priv->clk)) {
> + dev_err(dev, "No input reference clock\n");
> + return PTR_ERR(priv->clk);
> + }
> +
> + ret = clk_prepare_enable(priv->clk);
> + if (ret) {
> + dev_err(dev, "Failed to enable the reference clock, %d\n", ret);
> + return ret;
> + }
> +
> + ret = devm_add_action_or_reset(dev, (void (*) (void *))clk_disable_unprepare, priv->clk);
> + if (ret)
> + return ret;
> +
> + rate = clk_get_rate(priv->clk);
> + writew(rate & 0xFFFF, priv->rtc_base + REG_RTC_FREQ_CW_L);
> + writew((rate >> 16) & 0xFFFF, priv->rtc_base + REG_RTC_FREQ_CW_H);
> +
> + reg = readw(priv->rtc_base + REG_RTC_CTRL);
> + reg |= CNT_EN_BIT;
> + writew(reg, priv->rtc_base + REG_RTC_CTRL);
> +
If on POR, CNT_EN_BIT is not set, then it would be nice to use that to
know whether the RTC is properly set. You can then check CNT_EN_BIT in
.read_time and return -EINVAL if it is not set. Then you can set the bit
in .set_time. It is anyway useless to let the RTC running if it is not
set.
> + platform_set_drvdata(pdev, priv);
> +
> + return devm_rtc_register_device(priv->rtc_dev);
> +}
> +
> +static const struct of_device_id msc313_rtc_of_match_table[] = {
> + { .compatible = "mstar,msc313-rtc" },
> + { }
> +};
> +MODULE_DEVICE_TABLE(of, ms_rtc_of_match_table);
> +
> +static struct platform_driver msc313_rtc_driver = {
> + .probe = msc313_rtc_probe,
> + .driver = {
> + .name = "msc313-rtc",
> + .of_match_table = msc313_rtc_of_match_table,
> + },
> +};
> +
> +module_platform_driver(msc313_rtc_driver);
> +
> +MODULE_AUTHOR("Daniel Palmer <daniel@xxxxxxxxx>");
> +MODULE_AUTHOR("Romain Perier <romain.perier@xxxxxxxxx>");
> +MODULE_DESCRIPTION("MStar RTC Driver");
> +MODULE_LICENSE("GPL v2");
> --
> 2.30.2
>
--
Alexandre Belloni, co-owner and COO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
