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smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com; spf=pass smtp.mailfrom=bootlin.com; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b=b67JlGuC; arc=none smtp.client-ip=217.70.183.199 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=bootlin.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b="b67JlGuC" Received: by mail.gandi.net (Postfix) with ESMTPSA id 26DE544300; Thu, 13 Feb 2025 20:58:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1739480301; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=LWJiM1NFkSJ0D7UA78bKmM5hHyORgZQGH37a4foanvg=; b=b67JlGuCv3yJdSsndGs/nZkpiGYuhphZ7pGjGTTiU7QbULpqySbNoRzg6g/b9mZ1plFOF9 iiSZCrQdbFnpB39cmPO+F25DJft8U343DgI8Rp5buSMRtiJDyv+2Cxd/XgYqn2cWjJPgFJ cbbmdxOCqfxm5uFQGc0r3of/Jxg+b7/k7I4Ow5NUa+dwlGGHRRsAyC22uq4bYsXrPeoPk7 GLv4a9o2UjkuisxIFWbePEjQt90HCmYnc3Ov9dMhxNc7QrgjvzUcIJx5DdO4N4xq6ixznu mMacCfwcvgU1jVo/6m5aRFthKxWbyrTIFO4XJxPXHv6rOrPYV65LnXxpLlMbzQ== Date: Thu, 13 Feb 2025 21:58:18 +0100 From: Alexandre Belloni To: Alexander Sverdlin Cc: linux-riscv@lists.infradead.org, linux-rtc@vger.kernel.org, Jingbao Qiu , Inochi Amaoto , robh@kernel.org, krzysztof.kozlowski+dt@linaro.org, conor+dt@kernel.org, unicorn_wang@outlook.com, inochiama@outlook.com, paul.walmsley@sifive.com, palmer@dabbelt.com, aou@eecs.berkeley.edu, dlan@gentoo.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v10 2/2] rtc: sophgo: add rtc support for Sophgo CV1800 SoC Message-ID: <20250213205818f14edd30@mail.local> References: <20250213184622.2099324-1-alexander.sverdlin@gmail.com> <20250213184622.2099324-3-alexander.sverdlin@gmail.com> Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250213184622.2099324-3-alexander.sverdlin@gmail.com> X-GND-State: clean X-GND-Score: -100 X-GND-Cause: gggruggvucftvghtrhhoucdtuddrgeefvddrtddtgdegjeejlecutefuodetggdotefrodftvfcurfhrohhfihhlvgemucfitefpfffkpdcuggftfghnshhusghstghrihgsvgenuceurghilhhouhhtmecufedtudenucesvcftvggtihhpihgvnhhtshculddquddttddmnecujfgurhepfffhvfevuffkfhggtggujgesthdtredttddtvdenucfhrhhomheptehlvgigrghnughrvgcuuegvlhhlohhnihcuoegrlhgvgigrnhgurhgvrdgsvghllhhonhhisegsohhothhlihhnrdgtohhmqeenucggtffrrghtthgvrhhnpeegieduueethefhkeegjeevfefhiedujeeuhffgleejgfejgeekueejuefgheeggfenucffohhmrghinhepsghoohhtlhhinhdrtghomhenucfkphepvdgrtddumegvtdgrmedvugemieefjedtmeejkegvtdemtgdtvgekmedvkedtieemkegrtgeinecuvehluhhsthgvrhfuihiivgeptdenucfrrghrrghmpehinhgvthepvdgrtddumegvtdgrmedvugemieefjedtmeejkegvtdemtgdtvgekmedvkedtieemkegrtgeipdhhvghloheplhhotggrlhhhohhsthdpmhgrihhlfhhrohhmpegrlhgvgigrnhgurhgvrdgsvghllhhonhhisegsohhothhlihhnrdgtohhmpdhnsggprhgtphhtthhopeduiedprhgtphhtthhopegrlhgvgigrnhguvghrrdhsvhgvrhgulhhinhesghhmrghilhdrtghomhdprhgtphhtthhopehlihhnuhigqdhrihhstghvsehlihhsthhsrdhinhhfrhgruggvrggurdhor hhgpdhrtghpthhtoheplhhinhhugidqrhhttgesvhhgvghrrdhkvghrnhgvlhdrohhrghdprhgtphhtthhopehqihhujhhinhhgsggrohdrughlmhhusehgmhgrihhlrdgtohhmpdhrtghpthhtohepihhnohgthhhirghmrgesghhmrghilhdrtghomhdprhgtphhtthhopehrohgshheskhgvrhhnvghlrdhorhhgpdhrtghpthhtohepkhhriiihshiithhofhdrkhhoiihlohifshhkihdoughtsehlihhnrghrohdrohhrghdprhgtphhtthhopegtohhnohhrodgutheskhgvrhhnvghlrdhorhhg X-GND-Sasl: alexandre.belloni@bootlin.com On 13/02/2025 19:46:15+0100, Alexander Sverdlin wrote: > +static int cv1800_rtc_probe(struct platform_device *pdev) > +{ > + struct cv1800_rtc_priv *rtc; > + u32 ctrl_val; > + void __iomem *base; > + int ret; > + > + rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL); > + if (!rtc) > + return -ENOMEM; > + > + base = devm_platform_ioremap_resource(pdev, 0); > + if (IS_ERR(base)) > + return PTR_ERR(base); > + > + rtc->rtc_map = devm_regmap_init_mmio(&pdev->dev, base, > + &cv1800_rtc_regmap_config); > + if (IS_ERR(rtc->rtc_map)) > + return PTR_ERR(rtc->rtc_map); > + > + rtc->irq = platform_get_irq(pdev, 0); > + if (rtc->irq < 0) > + return rtc->irq; > + > + rtc->clk = devm_clk_get_enabled(&pdev->dev, NULL); > + if (IS_ERR(rtc->clk)) > + return dev_err_probe(&pdev->dev, PTR_ERR(rtc->clk), > + "clk not found\n"); > + > + platform_set_drvdata(pdev, rtc); > + > + device_init_wakeup(&pdev->dev, 1); > + > + rtc->rtc_dev = devm_rtc_allocate_device(&pdev->dev); > + if (IS_ERR(rtc->rtc_dev)) > + return PTR_ERR(rtc->rtc_dev); > + > + rtc->rtc_dev->ops = &cv1800_rtc_ops; > + rtc->rtc_dev->range_max = U32_MAX; > + > + ret = devm_request_irq(&pdev->dev, rtc->irq, cv1800_rtc_irq_handler, > + IRQF_TRIGGER_HIGH, "rtc alarm", rtc); > + if (ret) > + return dev_err_probe(&pdev->dev, ret, > + "cannot register interrupt handler\n"); > + > + rtc_enable_sec_counter(rtc); Really, this must be avoided, this loses precious information and changing it later will break users. What must be done is to check whether the RTC is started in .read_time if this is not the case, return -EINVAL instead of an invalid date/time. The RTC must be started once the time is set for the first time. This ensures we can detect when the time is invalid. > + > + return devm_rtc_register_device(rtc->rtc_dev); > +} > + > +static const struct of_device_id cv1800_dt_ids[] = { > + { .compatible = "sophgo,cv1800-rtc" }, > + { /* sentinel */ }, > +}; > +MODULE_DEVICE_TABLE(of, cv1800_dt_ids); > + > +static struct platform_driver cv1800_rtc_driver = { > + .driver = { > + .name = "sophgo-cv1800-rtc", > + .of_match_table = cv1800_dt_ids, > + }, > + .probe = cv1800_rtc_probe, > +}; > + > +module_platform_driver(cv1800_rtc_driver); > +MODULE_AUTHOR("Jingbao Qiu"); > +MODULE_DESCRIPTION("Sophgo cv1800 RTC Driver"); > +MODULE_LICENSE("GPL"); > -- > 2.48.1 > -- Alexandre Belloni, co-owner and COO, Bootlin Embedded Linux and Kernel engineering https://bootlin.com