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Message-ID: <d5341357-e0f4-afb1-20db-7c2d926662fe@quicinc.com>
Date:   Thu, 11 May 2023 11:12:37 +0530
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Subject: Re: [PATCH V6 2/3] soc: qcom: boot_stat: Add Driver Support for Boot
 Stats
To:     Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
CC:     Andy Gross <agross@kernel.org>,
        Konrad Dybcio <konrad.dybcio@somainline.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Bjorn Andersson <andersson@kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        <linux-arm-kernel@lists.infradead.org>,
        <linux-kernel@vger.kernel.org>, <linux-arm-msm@vger.kernel.org>,
        <devicetree@vger.kernel.org>, Sibi Sankar <quic_sibis@quicinc.com>,
        "Rajendra Nayak" <quic_rjendra@quicinc.com>
References: <cover.1683628357.git.quic_schowdhu@quicinc.com>
 <35863b47c04c2edd7ae49c57d23682aba6111d4f.1683628357.git.quic_schowdhu@quicinc.com>
 <CAA8EJppkqN6cuYUCC-THb8wb=deRv-01pbS0JgSGf-VXnm8qEg@mail.gmail.com>
 <82fcfc55-2879-2af0-5a91-4e9481d41976@quicinc.com>
 <CAA8EJprKumrq=Zy0gBqSZ9Dga5mZuauCC4U0GpTs0T4YADrSoA@mail.gmail.com>
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From:   Souradeep Chowdhury <quic_schowdhu@quicinc.com>
In-Reply-To: <CAA8EJprKumrq=Zy0gBqSZ9Dga5mZuauCC4U0GpTs0T4YADrSoA@mail.gmail.com>
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On 5/9/2023 6:31 PM, Dmitry Baryshkov wrote:
> On Tue, 9 May 2023 at 15:27, Souradeep Chowdhury
> <quic_schowdhu@quicinc.com> wrote:
>>
>>
>>
>> On 5/9/2023 5:09 PM, Dmitry Baryshkov wrote:
>>> On Tue, 9 May 2023 at 13:53, Souradeep Chowdhury
>>> <quic_schowdhu@quicinc.com> wrote:
> 
> 
>>>> diff --git a/drivers/soc/qcom/boot_stats.c b/drivers/soc/qcom/boot_stats.c
>>>> new file mode 100644
>>>> index 000000000000..ca67b6b5d8eb
>>>> --- /dev/null
>>>> +++ b/drivers/soc/qcom/boot_stats.c
>>>> @@ -0,0 +1,100 @@
>>>> +// SPDX-License-Identifier: GPL-2.0-only
>>>> +/*
>>>> + * Copyright (c) 2013-2019, 2021 The Linux Foundation. All rights reserved.
>>>> + * Copyright (c) 2023 Qualcomm Innovation Center, Inc. All rights reserved.
>>>> + */
>>>> +
>>>> +#include <linux/debugfs.h>
>>>> +#include <linux/err.h>
>>>> +#include <linux/io.h>
>>>> +#include <linux/init.h>
>>>> +#include <linux/kernel.h>
>>>> +#include <linux/module.h>
>>>> +#include <linux/of.h>
>>>> +#include <linux/of_address.h>
>>>> +#include <linux/platform_device.h>
>>>> +
>>>> +#define TO_MS(timestamp) ((timestamp * 1000) / 32768)
>>>
>>> Quoting v4 question, which got no answer:
>>>
>>> Some of the platforms DTs define 32KHz clock instead of 32.768 KHz
>>> What should be the divisor in this case?
>>
>> This is the standard divisor used to calculate the pre_abl and abl times
>> across most QCOM SoCs. Can you give an example where the sleep_stat
>> counter has a different frequency?
> 
> Following SoCs declare 37000 as sleep_clk frequency:
> ipq6018, qdu1000, qru1000, sc7280, sm6125, sm6375, sm8350, sm8450, sm8550.
> 
> This might be an error in the dtsi, or might be not.

This sleep_clk is different from the sleep_stats counter of the module 
power manager(MPM) which is used to log the timestamps. This driver is 
tested and verified with sm8450(waipio) which uses the same
frequency(32768).


> 
>>
>>>
>>>> +
>>>> +/**
>>>> + *  struct boot_stats - timestamp information related to boot stats
>>>> + *  @abl_start: Time for the starting point of the abl
>>>> + *  @abl_end: Time when the kernel starts loading from abl
>>>> + */
>>>> +struct boot_stats {
>>>> +       u32 abl_start;
>>>> +       u32 abl_end;
>>>> +} __packed;
>>>> +
>>>> +struct bs_data {
>>>> +       struct boot_stats __iomem *b_stats;
>>>> +       struct dentry *dbg_dir;
>>>> +};
>>>> +
>>>> +static void populate_boot_stats(char *abl_str, char *pre_abl_str, struct bs_data *drvdata)
>>>> +{
>>>> +        u32 abl_time, pre_abl_time;
>>>> +
>>>> +        abl_time = TO_MS(drvdata->b_stats->abl_end) - TO_MS(drvdata->b_stats->abl_start);
>>>> +        sprintf(abl_str, "%u ms", abl_time);
>>>> +
>>>> +        pre_abl_time =  TO_MS(drvdata->b_stats->abl_start);
>>>> +        sprintf(pre_abl_str, "%u ms", pre_abl_time);
>>>
>>> Another point from v4:
>>>
>>> It would be better to move the unit to the file name and include just
>>> the number.
>>
>> Clarified from your first comment
>>
>>>
>>>> +}
>>>> +
>>>> +static int boot_stats_probe(struct platform_device *pdev)
>>>> +{
>>>> +       char abl_str[20], pre_abl_str[20], *abl, *pre_abl;
>>>> +       struct device *bootstat_dev = &pdev->dev;
>>>> +       struct bs_data *drvdata;
>>>> +
>>>> +       drvdata = devm_kzalloc(bootstat_dev, sizeof(*drvdata), GFP_KERNEL);
>>>> +       if (!drvdata)
>>>> +               return dev_err_probe(bootstat_dev, -ENOMEM, "failed to allocate memory");
>>>> +       platform_set_drvdata(pdev, drvdata);
>>>> +
>>>> +       drvdata->b_stats = devm_of_iomap(bootstat_dev, bootstat_dev->of_node, 0, NULL);
>>>> +       if (IS_ERR(drvdata->b_stats))
>>>> +               return dev_err_probe(bootstat_dev, PTR_ERR(drvdata->b_stats),
>>>> +                                    "failed to map imem region");
>>>> +
>>>> +       drvdata->dbg_dir = debugfs_create_dir("qcom_boot_stats", NULL);
>>>> +       if (IS_ERR(drvdata->dbg_dir))
>>>> +               return dev_err_probe(bootstat_dev, PTR_ERR(drvdata->dbg_dir),
>>>> +                                    "failed to create debugfs directory");
>>>> +
>>>> +       populate_boot_stats(abl_str, pre_abl_str, drvdata);
>>>> +       abl = abl_str;
>>>> +       pre_abl = pre_abl_str;
>>>> +
>>>> +       debugfs_create_str("pre_abl_time", 0400, drvdata->dbg_dir, (char **)&pre_abl);
>>>> +       debugfs_create_str("abl_time", 0400, drvdata->dbg_dir, (char **)&abl);
>>>> +
>>>> +       return 0;
>>>> +}
>>>> +
>>>> +void boot_stats_remove(struct platform_device *pdev)
>>>> +{
>>>> +       struct bs_data *drvdata = platform_get_drvdata(pdev);
>>>> +
>>>> +       debugfs_remove_recursive(drvdata->dbg_dir);
>>>> +}
>>>> +
>>>> +static const struct of_device_id boot_stats_dt_match[] = {
>>>> +       { .compatible = "qcom,imem-bootstats" },
>>>> +       { }
>>>> +};
>>>> +MODULE_DEVICE_TABLE(of, boot_stats_dt_match);
>>>> +
>>>> +static struct platform_driver boot_stat_driver = {
>>>> +       .probe  = boot_stats_probe,
>>>> +       .remove_new = boot_stats_remove,
>>>> +       .driver = {
>>>> +               .name = "qcom-boot-stats",
>>>> +               .of_match_table = boot_stats_dt_match,
>>>> +       },
>>>> +};
>>>> +module_platform_driver(boot_stat_driver);
>>>> +
>>>> +MODULE_DESCRIPTION("Qualcomm Technologies Inc. Boot Stat driver");
>>>> +MODULE_LICENSE("GPL");
>>>> --
>>>> 2.17.1
>>>>
>>>
>>>
> 
> 
>