From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.15]) (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 A88EE36BCF2 for ; Tue, 2 Jun 2026 09:39:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.15 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780393164; cv=none; b=ahPNqj9Tj/fL4FtXyB95vrj8IKqDZpibDykN2vV5M0SoWTAno/JnCCFUKApVN+UEyq3l0vziT19SsRIcnU197DQM1HNRcZoK7TV3W2rKrykyDJaXhTPI+jpp1U2Sva1hTDzTlI0a1sql0vI0x+/+hj99S9Nyeqtn9CwQxRsz/c8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780393164; c=relaxed/simple; bh=5oC8ksAHTf+xBVKyW06yVS5MRSz5ZtAoCm0qkxSJeZQ=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=ghN/4VrvVDS3RL3MnbsjQAI2tlL6VjRojj3lFhEYqstS/tUHFnMIe3uAsoLDRk2DPc8M4L5j2dVnSn6DXBT1YRsmys16tu5euZe917mywmxlCvWwrKQ4hBRo1vN8Osjggt4mUBV0GgIH6x/2O1ujPJ5dFA2t1eewXhw/Lbpqz4o= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=anAfl9sZ; arc=none smtp.client-ip=198.175.65.15 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="anAfl9sZ" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1780393163; x=1811929163; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=5oC8ksAHTf+xBVKyW06yVS5MRSz5ZtAoCm0qkxSJeZQ=; b=anAfl9sZRTXk9XITFCRcEdKloCnlhxXPxO2Fx6I1TAyb/tp1rPb89mra wKCxvlBUOTK+qgxyJk8V18nLIBwE2ga8nNKnwkc+mj+t4RvHmp7XS0cts vCArkpS9BtA7Phk8wuwMqGjHmGphH2dOdSPyw0AKXM2pmKYxzDDKtanoa 8ZoxX+4A+jqXoi/ws5iggzagsGQB3AuvUuU0XeVT2kcNlvfCh/Xdzfd07 fGiRqGAGvj8w/LUMn1JR53hTC4s79lUnP7xFCMClRHSnonlyivLdfXWcG 4xYrtU5mJ80wrO2xIrWLNLlms0xE4EIaL9gvrVCDlIWbgOn62OooN6Qjz A==; X-CSE-ConnectionGUID: tz7oAOGxRwaEUupmVyodiQ== X-CSE-MsgGUID: rfHM0koURKybtyKFTswmTw== X-IronPort-AV: E=McAfee;i="6800,10657,11804"; a="84797711" X-IronPort-AV: E=Sophos;i="6.24,183,1774335600"; d="scan'208";a="84797711" Received: from fmviesa001.fm.intel.com ([10.60.135.141]) by orvoesa107.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 Jun 2026 02:39:22 -0700 X-CSE-ConnectionGUID: gSzDEjBvT1axWlMMHfCJ4A== X-CSE-MsgGUID: N47fI6AOTuSPh76YjMJXmw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.24,183,1774335600"; d="scan'208";a="267722861" Received: from mkosciow-mobl1.ger.corp.intel.com (HELO localhost) ([10.245.245.229]) by smtpauth.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 Jun 2026 02:39:18 -0700 Date: Tue, 2 Jun 2026 12:39:15 +0300 From: Andy Shevchenko To: Angelo Dureghello Cc: Greg Ungerer , Geert Uytterhoeven , Steven King , Arnd Bergmann , Maxime Coquelin , Alexandre Torgue , Jonathan Cameron , David Lechner , Nuno =?iso-8859-1?Q?S=E1?= , Andy Shevchenko , Greg Ungerer , linux-m68k@lists.linux-m68k.org, linux-kernel@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, linux-arm-kernel@lists.infradead.org, linux-iio@vger.kernel.org Subject: Re: [PATCH v4 11/11] iio: dac: add mcf54415 DAC Message-ID: References: <20260531-wip-stmark2-dac-v4-0-7e65ab4215dd@baylibre.com> <20260531-wip-stmark2-dac-v4-11-7e65ab4215dd@baylibre.com> Precedence: bulk X-Mailing-List: linux-m68k@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: <20260531-wip-stmark2-dac-v4-11-7e65ab4215dd@baylibre.com> Organization: Intel Finland Oy - BIC 0357606-4 - c/o Alberga Business Park, 6 krs, Bertel Jungin Aukio 5, 02600 Espoo On Sun, May 31, 2026 at 05:26:04PM +0200, Angelo Dureghello wrote: > Add basic version of mcf54415 DAC driver. DAC is embedded in the cpu and CPU (or maybe you wanted use 'SoC' acronym) > DAC configuration registers are mapped in the internal IO address space. > > The DAC accepts a 12-bit digital signal and creates a monotonic 12-bit > analog output varying from DAC_VREFL to DAC_VREFH. The DAC module > consists of a conversion unit, an output amplifier, and the associated > digital control blocks. Default register values for DAC_VREFL and DAC_VREFH > are respectively 0 and 0xfff, left untouched in this initial version. > > This initial version of the driver is minimalistic, "output raw" only, to > be extended in the future. DMA and external sync are disabled, default mode > is high speed, default format is right-justified 12bit on 16bit word. Be consistent: 12-bit on 16-bit ... > Changes in v4: > - remove unused includes > - sashiko: return "ret" as regmap_read ret value in case of error > - sashiko: using u32 as regmap_read value Why? regmap API uses 'unsigned int'. Then you can take out any bits, fields, et cetera from it into fixed-width type of variables. > - use local variable in mcf54415_dac_init() for better readability > - sashiko: check mcf54415_dac_init return value also in resume() ... > +#include > +#include > +#include > +#include Drop this (see below). > +#include > +#include > +#include > +#include > +#include > +#include + types.h (it also guarantees compile_types.h). ... > +static int mcf54415_dac_init(struct mcf54415_dac *info) > +{ > + int ret; > + u16 val = MCF54415_DAC_CR_FILT | FIELD_PREP(MCF54415_DAC_CR_WMLVL, 1); Can we move towards reversed xmas tree order? u16 val = MCF54415_DAC_CR_FILT | FIELD_PREP(MCF54415_DAC_CR_WMLVL, 1); int ret; > + /* Fixed defaults and enable DAC (bit 0 set to 0) */ > + ret = regmap_write(info->map, MCF54415_DAC_CR, val); > + if (ret) > + return ret; > + > + /* DAC is ready after 12us, from RM table 40-3 */ > + fsleep(12); > + > + return 0; > +} ... > +static int mcf54415_write_raw(struct iio_dev *indio_dev, > + struct iio_chan_spec const *chan, > + int val, int val2, long mask) > +{ > + struct mcf54415_dac *info = iio_priv(indio_dev); > + > + switch (mask) { > + case IIO_CHAN_INFO_RAW: > + /* Check based on RM 30.3.2 (DACn_DATA) reg. resolution */ > + if (val < 0 || val > 4095) > + return -EINVAL; > + return regmap_write(info->map, MCF54415_DAC_DATA, val); So, for example, -1 will be written as 0xffffffff (with the respective bits taken into account). Is it a problem? > + default: > + return -EINVAL; > + } > +} ... > +static int mcf54415_dac_probe(struct platform_device *pdev) > +{ > + struct device *dev = &pdev->dev; > + struct iio_dev *indio_dev; > + struct mcf54415_dac *info; > + void __iomem *regs; > + int ret; > + > + indio_dev = devm_iio_device_alloc(dev, sizeof(*info)); > + if (!indio_dev) > + return -ENOMEM; > + > + info = iio_priv(indio_dev); > + > + regs = devm_platform_ioremap_resource(pdev, 0); > + if (IS_ERR(regs)) > + return dev_err_probe(dev, PTR_ERR(regs), > + "failed to get io regs\n"); One line. It's more than decade that checkpatch stopped complaining on the trailing string literals. > + info->map = devm_regmap_init_mmio(dev, regs, > + &mcf54415_dac_regmap_config); One line (yes, 82 characters). > + if (IS_ERR(info->map)) > + return PTR_ERR(info->map); > + > + info->clk = devm_clk_get_enabled(dev, "dac"); > + if (IS_ERR(info->clk)) > + return dev_err_probe(dev, PTR_ERR(info->clk), > + "failed getting clock\n"); Also one line. > + platform_set_drvdata(pdev, indio_dev); > + > + indio_dev->name = "mcf54415"; > + indio_dev->info = &mcf54415_dac_iio_info; > + indio_dev->modes = INDIO_DIRECT_MODE; > + indio_dev->channels = &mcf54415_dac_iio_channel; > + indio_dev->num_channels = 1; > + > + ret = mcf54415_dac_init(info); > + if (ret) > + return ret; > + > + ret = devm_add_action_or_reset(dev, mcf54415_dac_exit, info); > + if (ret) > + return ret; > + > + return devm_iio_device_register(dev, indio_dev); > +} ... > +static int mcf54415_dac_resume(struct device *dev) > +{ > + struct mcf54415_dac *info = iio_priv(dev_get_drvdata(dev)); > + int ret; > + > + ret = clk_prepare_enable(info->clk); > + if (ret) > + return ret; > + > + ret = mcf54415_dac_init(info); > + if (ret) { > + dev_err(dev, "could not resume device\n"); > + return ret; > + } > + > + return 0; > + Besides stray blank line the above can be ret = mcf54415_dac_init(info); if (ret) dev_err(dev, "could not resume device\n"); return ret; > +} -- With Best Regards, Andy Shevchenko