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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 2D3EDC433E0 for ; Fri, 5 Jun 2020 12:46:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 13D062065C for ; Fri, 5 Jun 2020 12:46:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726557AbgFEMqq (ORCPT ); Fri, 5 Jun 2020 08:46:46 -0400 Received: from mga04.intel.com ([192.55.52.120]:39855 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726499AbgFEMqq (ORCPT ); Fri, 5 Jun 2020 08:46:46 -0400 IronPort-SDR: +rPeI5uZh0OMljZuxl/TdFc7ZIRmLmLmX911sCr55Hb+7EG2AS8LdwoqghjBWlzW4T55Rd3gnc UXbgTnpooerQ== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Jun 2020 05:46:45 -0700 IronPort-SDR: r/oJX8fhNmc8e/bISoUrjyeoU9guHWxK+HVaeG11SzZWS7YbfeGTMiJ95UKT4qtI63FTHd0jO8 yFEOq6VRqCWQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.73,476,1583222400"; d="scan'208";a="269755373" Received: from smile.fi.intel.com (HELO smile) ([10.237.68.40]) by orsmga003.jf.intel.com with ESMTP; 05 Jun 2020 05:46:41 -0700 Received: from andy by smile with local (Exim 4.93) (envelope-from ) id 1jhBkB-00B1rI-FV; Fri, 05 Jun 2020 15:46:43 +0300 Date: Fri, 5 Jun 2020 15:46:43 +0300 From: Andy Shevchenko To: Dongchun Zhu Cc: linus.walleij@linaro.org, bgolaszewski@baylibre.com, mchehab@kernel.org, robh+dt@kernel.org, mark.rutland@arm.com, sakari.ailus@linux.intel.com, drinkcat@chromium.org, tfiga@chromium.org, matthias.bgg@gmail.com, bingbu.cao@intel.com, srv_heupstream@mediatek.com, linux-mediatek@lists.infradead.org, linux-arm-kernel@lists.infradead.org, sj.huang@mediatek.com, linux-media@vger.kernel.org, devicetree@vger.kernel.org, louis.kuo@mediatek.com, shengnan.wang@mediatek.com Subject: Re: [V7, 2/2] media: i2c: dw9768: Add DW9768 VCM driver Message-ID: <20200605124643.GG2428291@smile.fi.intel.com> References: <20200605105412.18813-1-dongchun.zhu@mediatek.com> <20200605105412.18813-3-dongchun.zhu@mediatek.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200605105412.18813-3-dongchun.zhu@mediatek.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo Sender: devicetree-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On Fri, Jun 05, 2020 at 06:54:12PM +0800, Dongchun Zhu wrote: > Add a V4L2 sub-device driver for DW9768 voice coil motor, providing > control to set the desired focus via IIC serial interface. ... > +config VIDEO_DW9768 > + tristate "DW9768 lens voice coil support" > + depends on I2C && VIDEO_V4L2 No compile test? > + depends on PM This is very strange dependency for ordinary driver. > + select MEDIA_CONTROLLER > + select VIDEO_V4L2_SUBDEV_API > + select V4L2_FWNODE ... > +/* > + * DW9768 requires waiting time (delay time) of t_OPR after power-up, > + * or in the case of PD reset taking place. > + */ > +#define DW9768_T_OPR_US 1000 > +#define DW9768_Tvib_MS_BASE10 (64 - 1) > +#define DW9768_AAC_MODE_DEFAULT 2 > +#define DW9768_AAC_TIME_DEFAULT 0x20 Hex? Why not decimal? > +#define DW9768_CLOCK_PRE_SCALE_DEFAULT 1 ... > +static int dw9768_mod_reg(struct dw9768 *dw9768, u8 reg, u8 mask, u8 val) > +{ > + struct i2c_client *client = v4l2_get_subdevdata(&dw9768->sd); > + int ret; > + > + ret = i2c_smbus_read_byte_data(client, reg); > + if (ret < 0) > + return ret; > + > + val = ((unsigned char)ret & ~mask) | (val & mask); This cast is weird. > + > + return i2c_smbus_write_byte_data(client, reg, val); > +} ... > + dev_err(&client->dev, "%s I2C failure: %d", > + __func__, ret); One line? ... > +static int dw9768_release(struct dw9768 *dw9768) > +{ > + struct i2c_client *client = v4l2_get_subdevdata(&dw9768->sd); > + u32 move_delay_us = dw9768_cal_move_delay(dw9768->aac_mode, > + dw9768->clock_presc, > + dw9768->aac_timing) / 100; > + int ret, val; > + > + val = round_down(dw9768->focus->val, DW9768_MOVE_STEPS); > + for ( ; val >= 0; val -= DW9768_MOVE_STEPS) { > + ret = dw9768_set_dac(dw9768, val); > + if (ret) { > + dev_err(&client->dev, "I2C write fail: %d", ret); > + return ret; > + } > + usleep_range(move_delay_us, move_delay_us + 1000); > + } It will look more naturally in the multiplier kind of value. unsigned int steps = DIV_ROUND_UP(...); while (steps--) { ...(..., steps * ..._MOVE_STEPS); ... } but double check arithmetics. > + return 0; > +} Also it seems we need to have writex_poll_timeout() implementation (see iopoll.h). -- With Best Regards, Andy Shevchenko