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smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=p9CRFwTF; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="p9CRFwTF" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 39038C4CEE3; Fri, 13 Jun 2025 13:11:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1749820300; bh=RbLt8//FrHv3yzSlHkAnJ39jGaCI5d6TuBafqw1Iais=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=p9CRFwTFQB6b2MRLIiu64qe3eBQOQuybf4O9R2ndSQD5+AQW0G9ttxIY4zPnD8CIR PEgjQ6UJ9A02nWnYEZ4hdjuxmmKz6W9EADdVr1GVQ9lQW4/UCuMqUoNBuQ/te93Ads cupoMj4pmBj6bu8exL7TUN4N6fe3dwCeRUtCkKcrAaTyCPyrwDvvZGOM/cWMKITupY WkCpdeJQcDK/SPlMYkK5Q+JsHKtoHx/lUn4cW8iI9i1NkACjO9b4KBYGoCGY0bLYUd /EVAoP7PxxLSUHNVxHonbuFweNJhlAClNBBdHHSNUjgrkmZ3M5/m9a2Kqx1y+Katy8 TgWiR9/xkyNpg== Date: Fri, 13 Jun 2025 14:11:33 +0100 From: Lee Jones To: Ming Yu Cc: linus.walleij@linaro.org, brgl@bgdev.pl, andi.shyti@kernel.org, mkl@pengutronix.de, mailhol.vincent@wanadoo.fr, andrew+netdev@lunn.ch, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, wim@linux-watchdog.org, linux@roeck-us.net, jdelvare@suse.com, alexandre.belloni@bootlin.com, linux-kernel@vger.kernel.org, linux-gpio@vger.kernel.org, linux-i2c@vger.kernel.org, linux-can@vger.kernel.org, netdev@vger.kernel.org, linux-watchdog@vger.kernel.org, linux-hwmon@vger.kernel.org, linux-rtc@vger.kernel.org, linux-usb@vger.kernel.org, Ming Yu Subject: Re: [PATCH v12 1/7] mfd: Add core driver for Nuvoton NCT6694 Message-ID: <20250613131133.GR381401@google.com> References: <20250604041418.1188792-1-tmyu0@nuvoton.com> <20250604041418.1188792-2-tmyu0@nuvoton.com> <20250612140041.GF381401@google.com> <20250612152313.GP381401@google.com> Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: On Fri, 13 Jun 2025, Ming Yu wrote: > Lee Jones 於 2025年6月12日 週四 下午11:23寫道： > > > > On Thu, 12 Jun 2025, Ming Yu wrote: > > > > > Dear Lee, > > > > > > Thank you for reviewing, > > > > > > Lee Jones 於 2025年6月12日 週四 下午10:00寫道： > > > > > > > ... > > > > > +static const struct mfd_cell nct6694_devs[] = { > > > > > + MFD_CELL_BASIC("nct6694-gpio", NULL, NULL, 0, 0), > > > > > + MFD_CELL_BASIC("nct6694-gpio", NULL, NULL, 0, 1), > > > > > + MFD_CELL_BASIC("nct6694-gpio", NULL, NULL, 0, 2), > > > > > + MFD_CELL_BASIC("nct6694-gpio", NULL, NULL, 0, 3), > > > > > + MFD_CELL_BASIC("nct6694-gpio", NULL, NULL, 0, 4), > > > > > + MFD_CELL_BASIC("nct6694-gpio", NULL, NULL, 0, 5), > > > > > + MFD_CELL_BASIC("nct6694-gpio", NULL, NULL, 0, 6), > > > > > + MFD_CELL_BASIC("nct6694-gpio", NULL, NULL, 0, 7), > > > > > + MFD_CELL_BASIC("nct6694-gpio", NULL, NULL, 0, 8), > > > > > + MFD_CELL_BASIC("nct6694-gpio", NULL, NULL, 0, 9), > > > > > + MFD_CELL_BASIC("nct6694-gpio", NULL, NULL, 0, 10), > > > > > + MFD_CELL_BASIC("nct6694-gpio", NULL, NULL, 0, 11), > > > > > + MFD_CELL_BASIC("nct6694-gpio", NULL, NULL, 0, 12), > > > > > + MFD_CELL_BASIC("nct6694-gpio", NULL, NULL, 0, 13), > > > > > + MFD_CELL_BASIC("nct6694-gpio", NULL, NULL, 0, 14), > > > > > + MFD_CELL_BASIC("nct6694-gpio", NULL, NULL, 0, 15), > > > > > + > > > > > + MFD_CELL_BASIC("nct6694-i2c", NULL, NULL, 0, 0), > > > > > + MFD_CELL_BASIC("nct6694-i2c", NULL, NULL, 0, 1), > > > > > + MFD_CELL_BASIC("nct6694-i2c", NULL, NULL, 0, 2), > > > > > + MFD_CELL_BASIC("nct6694-i2c", NULL, NULL, 0, 3), > > > > > + MFD_CELL_BASIC("nct6694-i2c", NULL, NULL, 0, 4), > > > > > + MFD_CELL_BASIC("nct6694-i2c", NULL, NULL, 0, 5), > > > > > > > > Why have we gone back to this silly numbering scheme? > > > > > > > > What happened to using IDA in the child driver? > > > > > > > > > > In a previous version, I tried to maintain a static IDA in each > > > sub-driver. However, I didn’t consider the case where multiple NCT6694 > > > devices are bound to the same driver — in that case, the IDs are not > > > fixed and become unusable for my purpose. > > > > Not sure I understand. > > > > As far as I know, if I maintain the IDA in the sub-drivers and use > multiple MFD_CELL_NAME("nct6694-gpio") entries in the MFD, the first > NCT6694 device bound to the GPIO driver will receive IDs 0~15. > However, when a second NCT6694 device is connected to the system, it > will receive IDs 16~31. > Because of this behavior, I switched back to using platform_device->id. Each of the devices will probe once. The first one will be given 0, the second will be given 1, etc. Why would you give multiple IDs to a single device bound to a driver? -- Lee Jones [李琼斯]