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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 50EE7ECAAD1 for ; Thu, 1 Sep 2022 08:40:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233384AbiIAIkV (ORCPT ); Thu, 1 Sep 2022 04:40:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37486 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233358AbiIAIkU (ORCPT ); Thu, 1 Sep 2022 04:40:20 -0400 Received: from smtp-fw-6001.amazon.com (smtp-fw-6001.amazon.com [52.95.48.154]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6755C3D5A3; Thu, 1 Sep 2022 01:40:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1662021619; x=1693557619; h=message-id:date:mime-version:to:cc:references:from: in-reply-to:content-transfer-encoding:subject; 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Thu, 1 Sep 2022 08:40:04 +0000 Received: from [192.168.93.228] (10.85.143.172) by mail-relay.amazon.com (10.43.62.224) with Microsoft SMTP Server id 15.0.1497.38 via Frontend Transport; Thu, 1 Sep 2022 08:39:59 +0000 Message-ID: <2f5c5828-87b9-f3d2-e3d3-0200adbe830c@amazon.com> Date: Thu, 1 Sep 2022 11:39:58 +0300 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.2.0 Content-Language: en-US To: Guenter Roeck , , , , , , , CC: , , , , , , , , , , , , "Farber, Eliav" References: <20220830192212.28570-1-farbere@amazon.com> <20220830192212.28570-3-farbere@amazon.com> <84a68eff-be64-71ce-1533-1e228d3da2a4@amazon.com> <71d6d57c-2165-5fe3-515d-9395022921e2@roeck-us.net> From: "Farber, Eliav" In-Reply-To: <71d6d57c-2165-5fe3-515d-9395022921e2@roeck-us.net> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On 8/31/2022 2:48 PM, Guenter Roeck wrote: > On 8/30/22 22:49, Farber, Eliav wrote: >> On 8/31/2022 8:36 AM, Guenter Roeck wrote: >>> On 8/30/22 12:21, Eliav Farber wrote: >>>> Bug fix - in case "intel,vm-map" is missing in device-tree ,'num' >>>> is set >>>> to 0, and no voltage channel infos are allocated. >>>> >>>> Signed-off-by: Eliav Farber >>>> --- >>>>   drivers/hwmon/mr75203.c | 28 ++++++++++++---------------- >>>>   1 file changed, 12 insertions(+), 16 deletions(-) >>>> >>>> diff --git a/drivers/hwmon/mr75203.c b/drivers/hwmon/mr75203.c >>>> index 046523d47c29..0e29877a1a9c 100644 >>>> --- a/drivers/hwmon/mr75203.c >>>> +++ b/drivers/hwmon/mr75203.c >>>> @@ -580,8 +580,6 @@ static int mr75203_probe(struct platform_device >>>> *pdev) >>>>       } >>>> >>>>       if (vm_num) { >>>> -             u32 num = vm_num; >>>> - >>>>               ret = pvt_get_regmap(pdev, "vm", pvt); >>>>               if (ret) >>>>                       return ret; >>>> @@ -594,30 +592,28 @@ static int mr75203_probe(struct >>>> platform_device *pdev) >>>>               ret = device_property_read_u8_array(dev, "intel,vm-map", >>>> pvt->vm_idx, vm_num); >>>>               if (ret) { >>>> -                     num = 0; >>>> +                     /* >>>> +                      * Incase intel,vm-map property is not >>>> defined, we >>>> +                      * assume incremental channel numbers. >>>> +                      */ >>>> +                     for (i = 0; i < vm_num; i++) >>>> +                             pvt->vm_idx[i] = i; >>>>               } else { >>>>                       for (i = 0; i < vm_num; i++) >>>>                               if (pvt->vm_idx[i] >= vm_num || >>>> -                                 pvt->vm_idx[i] == 0xff) { >>>> -                                     num = i; >>>> +                                 pvt->vm_idx[i] == 0xff) >>>>                                       break; >>> >>> So all vm_idx values from 0x00 to 0xfe would be acceptable ? >>> Does the chip really have that many registers (0x200 + 0x40 + 0x200 >>> * 0xfe) ? >>> Is that documented somewhere ? >> According to the code vm_num is limited to 32 because the mask is >> only 5 bits: >> >> #define VM_NUM_MSK    GENMASK(20, 16) >> #define VM_NUM_SFT    16 >> vm_num = (val & VM_NUM_MSK) >> VM_NUM_SFT; >> >> In practice according to the data sheet I have: >> 0 <= VM instances <= 8 >> > Sorry, my bad. I misread the patch and thought the first part of > the if statement was removed. > > Anyway, what is the difference between specifying an vm_idx value of > 0xff and not specifying anything ? Or, in other words, taking the dt > example, the difference between >        intel,vm-map = [03 01 04 ff ff]; > and >        intel,vm-map = [03 01 04]; The actual number of VMs is read from a HW register:     ret = regmap_read(pvt->c_map, PVT_IP_CONFIG, &val);     ...     vm_num = (val & VM_NUM_MSK) >> VM_NUM_SFT; Also, using:     ret = device_property_read_u8_array(dev, "intel,vm-map", vm_idx,                         vm_num); in the driver will fail if vm_num > sizeof array in device-tree. So, if for example vm_num = 5, but you will want to map only 3 of them you most set property to be:     intel,vm-map = [03 01 04 ff ff]; otherwise if you set:     intel,vm-map = [03 01 04]; it will assume the property doesn't, and will continue the flow in code as if it doesn’t exist (which is not what the user wanted, and before my fix also has a bug). -- Regards, Eliav