From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EC7D4C432BE for ; Fri, 6 Aug 2021 19:38:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D208261179 for ; Fri, 6 Aug 2021 19:38:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230090AbhHFTiW (ORCPT ); Fri, 6 Aug 2021 15:38:22 -0400 Received: from relay10.mail.gandi.net ([217.70.178.230]:41229 "EHLO relay10.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229748AbhHFTiW (ORCPT ); Fri, 6 Aug 2021 15:38:22 -0400 Received: (Authenticated sender: alexandre.belloni@bootlin.com) by relay10.mail.gandi.net (Postfix) with ESMTPSA id 9F8D4240006; Fri, 6 Aug 2021 19:38:03 +0000 (UTC) Date: Fri, 6 Aug 2021 21:38:03 +0200 From: Alexandre Belloni To: Romain Perier Cc: Alessandro Zummo , Daniel Palmer , Rob Herring , linux-rtc@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v2 2/3] rtc: Add support for the MSTAR MSC313 RTC Message-ID: References: <20210801160921.233081-1-romain.perier@gmail.com> <20210801160921.233081-3-romain.perier@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210801160921.233081-3-romain.perier@gmail.com> Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org 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 "); > +MODULE_AUTHOR("Romain Perier "); > +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