From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DB196348C4A; Thu, 30 Jul 2026 09:09:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785402561; cv=none; b=l8/s6IcK62aff6x7GGItpOrzDPzjW58XG2t0trtdnE1mEa4evgMun8GJMmV637k86vqQs5WSnf6Z2d/CG0L8EVBXhwweAXZzLZHYV0HCIch02Dxnk9PJEZALwpjAV305ruCjYUlBhpSBdTBVOJYGkQ0uKMzBsSzhGaV5YbC1eqE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785402561; c=relaxed/simple; bh=8aI96xTt1FQlltGppSKP7p1b+xTt/C81QT+pshUKJfE=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=CiYE4iNFni0Jn28Ecq1zLL4vDJTGDDkFjJQIN3xGSV7UzgAzTWm65+0DLv9K4hlxGH4TeXGanK8BOPxJGLpS67yJ7fpoBcnoZjui/W/lw16VAQgyLqf3DOvk5hIIEQjciV3KQqKDd1ymDY1UGBRqdcYO8f2G9HKpSAkyH6fUsgM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=MMpnSSzR; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="MMpnSSzR" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 999561F000E9; Thu, 30 Jul 2026 09:09:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1785402560; bh=5JB5xncxO/PaAUBUbRddlHPk/+gwtswZ1zFbQ3Aty4g=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=MMpnSSzRGJR8UaoMkNvFaybhg0040nwK47TWpjW3KGL6SU6YgE+p1UBZ85Gj75De7 xADR2OLvsWObN8lq8G2GxiJQjfn3W5FX3fdOr/epkrRNaaklOYKWiR4fpO+5ObjvdW EB7+17emtW72RMn0FkkEowV/8kw9hGWpjcb6J4DAA4wyuOKAYRr0X8oM7sAgbMrSoU EcHgtrSxduhIW3WBWkw5XCuXUh+PhW7DiwSllwQ3ezBxxww0PJ49eVyvaIoauiZRpb ytdzCUChUnf9G46NvW7coLPn31baAQyVlO28nqLQLbh6crTyQ0HrhmzCvCjTXGQf8f TZkv5TAQfhR2Q== Date: Thu, 30 Jul 2026 11:09:16 +0200 From: Krzysztof Kozlowski To: Lachlan Michael Cc: mchehab@kernel.org, sakari.ailus@linux.intel.com, hverkuil+cisco@kernel.org, laurent.pinchart@ideasonboard.com, linux-media@vger.kernel.org, devicetree@vger.kernel.org, robh@kernel.org, krzk+dt@kernel.org, conor+dt@kernel.org, kieran.bingham@ideasonboard.com, jai.luthra@ideasonboard.com, Ryuichi.Tadano@sony.com, Kengo.Hayasaka@sony.com, Tim.Bird@sony.com, Kazumi.A.Sato@sony.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/2] media: i2c: Add Sony IMX908 image sensor driver Message-ID: <20260730-ruddy-tricky-wildebeest-ec9e46@quoll> References: <20260730021525.166811-1-lachlan.michael@sony.com> <20260730021525.166811-3-lachlan.michael@sony.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=utf-8 Content-Disposition: inline In-Reply-To: <20260730021525.166811-3-lachlan.michael@sony.com> On Thu, Jul 30, 2026 at 11:15:25AM +0900, Lachlan Michael wrote: > + msleep(24); /* Regulator stabilization after standby cancel. */ > + > + ret = cci_read(imx->cci, IMX908_REG_TYPE_ID, &val, &err); > + if (ret || err) > + return ret ? ret : err; > + > + chip_id = val; > + dev_info(imx->dev, "IMX908 chip ID: 0x%04x\n", chip_id); Drivers should be silent on success. Drop or dev_dbg. > + > + if (chip_id != IMX908_CHIP_ID) { > + dev_err(imx->dev, "Unexpected chip ID 0x%04x (expected 0x%04x)\n", > + chip_id, IMX908_CHIP_ID); > + return -ENXIO; > + } > + > + /* Set to standby mode */ > + ret = cci_write(imx->cci, IMX908_REG_STANDBY, IMX908_STANDBY_EN, NULL); > + if (ret) > + dev_err(imx->dev, "failed to enter standby state: %d\n", ret); > + > + return 0; > +} > + > +static int imx908_probe(struct i2c_client *client) > +{ > + struct imx908 *imx; > + int ret; > + > + /* Allocate Memory */ Really? > + imx = devm_kzalloc(&client->dev, sizeof(*imx), GFP_KERNEL); > + if (!imx) > + return dev_err_probe(&client->dev, -ENOMEM, > + "failed to allocate IMX908 device structure\n"); > + imx->dev = &client->dev; > + > + /* Initialize V4L2 subdevice */ Obvious. > + v4l2_i2c_subdev_init(&imx->sd, client, &imx908_subdev_ops); > + imx->sd.internal_ops = &imx908_internal_ops; > + > + /* Register access initialization. Set 2-byte (16-bit) addresses */ > + imx->cci = devm_cci_regmap_init_i2c(client, 16); > + if (IS_ERR(imx->cci)) > + return dev_err_probe(&client->dev, PTR_ERR(imx->cci), > + "CCI regmap init failed\n"); > + > + /* Get mandatory input clock from DT (INCK) */ Obvious. > + imx->xclk = devm_clk_get(imx->dev, "xclk"); > + if (IS_ERR(imx->xclk)) > + return dev_err_probe(imx->dev, PTR_ERR(imx->xclk), "xclk\n"); > + > + /* Get clock frequency and check against acceptable HW values */ > + imx->xclk_freq = clk_get_rate(imx->xclk); > + ret = imx908_get_inck_sel(imx); > + if (ret) > + return ret; > + > + /* GPIO reset acquisition */ Please drop obvious comments. Can devm_gpiod_get_optional() be anything else than GPIO reset acquisition? No. Redundant comments bloat the code and make it more difficult to actually spot important things. > + imx->reset_gpio = devm_gpiod_get_optional(imx->dev, "reset", > + GPIOD_OUT_HIGH); > + > + if (IS_ERR(imx->reset_gpio)) > + return dev_err_probe(imx->dev, PTR_ERR(imx->reset_gpio), > + "reset gpio\n"); > + > + /* Link to power supplies */ > + ret = imx908_get_regulators(imx); > + if (ret) > + return dev_err_probe(&client->dev, ret, > + "regulator get failed\n"); > + > + /* Parse Device Tree endpoint */ Obvious > + ret = imx908_parse_fwnode(imx); > + if (ret) > + return dev_err_probe(&client->dev, ret, > + "device tree parse failed\n"); > + > + /* Power on IMX908 image sensor */ What if imx908_power_on() does power off of the sensor? > + ret = imx908_power_on(imx); > + if (ret) > + return dev_err_probe(&client->dev, ret, "power-on failed\n"); > + > + /* Read IMX908 device ID */ Best regards, Krzysztof