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Message-ID: <195c7961-92cc-b41d-52ba-383b10dd9c75@quicinc.com>
Date:   Tue, 1 Aug 2023 11:41:43 +0530
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Subject: Re: [PATCH v5 2/2] nvmem: sec-qfprom: Add Qualcomm secure QFPROM
 support
Content-Language: en-US
To:     Mukesh Ojha <quic_mojha@quicinc.com>,
        Srinivas Kandagatla <srinivas.kandagatla@linaro.org>,
        <agross@kernel.org>, <andersson@kernel.org>,
        <konrad.dybcio@linaro.org>, <robh+dt@kernel.org>,
        <krzysztof.kozlowski+dt@linaro.org>, <conor+dt@kernel.org>
CC:     <linux-arm-msm@vger.kernel.org>, <devicetree@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>
References: <20230724083849.8277-1-quic_kbajaj@quicinc.com>
 <20230724083849.8277-3-quic_kbajaj@quicinc.com>
 <f6fab6b7-0cfb-6aa5-2043-6c789709d04a@linaro.org>
 <f38f3a60-28c1-7566-3772-21edb70d4c9c@quicinc.com>
From:   Komal Bajaj <quic_kbajaj@quicinc.com>
In-Reply-To: <f38f3a60-28c1-7566-3772-21edb70d4c9c@quicinc.com>
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On 7/28/2023 1:55 PM, Mukesh Ojha wrote:
>
>
> On 7/27/2023 4:14 PM, Srinivas Kandagatla wrote:
>>
>>
>> On 24/07/2023 09:38, Komal Bajaj wrote:
>>> For some of the Qualcomm SoC's, it is possible that
>>> some of the fuse regions or entire qfprom region is
>>> protected from non-secure access. In such situations,
>>> Linux will have to use secure calls to read the region.
>>> With that motivation, add secure qfprom driver.
>>>
>>> Signed-off-by: Komal Bajaj <quic_kbajaj@quicinc.com>
>>> ---
>>>   drivers/nvmem/Kconfig      |  13 +++++
>>>   drivers/nvmem/Makefile     |   2 +
>>>   drivers/nvmem/sec-qfprom.c | 101 
>>> +++++++++++++++++++++++++++++++++++++
>>>   3 files changed, 116 insertions(+)
>>>   create mode 100644 drivers/nvmem/sec-qfprom.c
>>>
>>
>>> diff --git a/drivers/nvmem/sec-qfprom.c b/drivers/nvmem/sec-qfprom.c
>>> new file mode 100644
>>> index 000000000000..bc68053b7d94
>>> --- /dev/null
>>> +++ b/drivers/nvmem/sec-qfprom.c
>>> @@ -0,0 +1,101 @@
>>> +// SPDX-License-Identifier: GPL-2.0-only
>>> +/*
>>> + * Copyright (c) 2023, Qualcomm Innovation Center, Inc. All rights 
>>> reserved.
>>> + */
>>> +
>>> +#include <linux/firmware/qcom/qcom_scm.h>
>>> +#include <linux/mod_devicetable.h>
>>> +#include <linux/nvmem-provider.h>
>>> +#include <linux/platform_device.h>
>>> +#include <linux/pm_runtime.h>
>>
>>> +
>>> +static int sec_qfprom_probe(struct platform_device *pdev)
>>> +{
>>> +    struct nvmem_config econfig = {
>>> +        .name = "sec-qfprom",
>>> +        .stride = 1,
>>> +        .word_size = 1,
>>> +        .id = NVMEM_DEVID_AUTO,
>>> +        .reg_read = sec_qfprom_reg_read,
>>> +    };
>>> +    struct device *dev = &pdev->dev;
>>> +    struct nvmem_device *nvmem;
>>> +    struct sec_qfprom *priv;
>>> +    struct resource *res;
>>> +    int ret;
>>> +
>>> +    priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
>>> +    if (!priv)
>>> +        return -ENOMEM;
>>> +
>>> +    res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>>> +    if (!res)
>>> +        return -EINVAL;
>>> +
>>> +    priv->base = res->start;
>>> +
>>> +    econfig.size = resource_size(res);
>>> +    econfig.dev = dev;
>>> +    econfig.priv = priv;
>>> +
>>> +    priv->dev = dev;
>>> +
>>> +    ret = devm_pm_runtime_enable(dev);
>>> +    if (ret)
>>> +        return ret;
>>
>> Any reason why we need to enable pm runtime for this driver? As Am 
>> not seeing any pm runtime handlers or users in this driver.
>
> Thanks..
> Yes, it is not needed as of now..
> looks like, it got inherited from qfprom.c by mistake.
>
> Same need to be corrected in Device tree, if any
> unnecessary reference is there related to this..

Thanks for pointing it out.
Will drop it in the next patch series.

Thanks
Komal

>
> -Mukesh
>>
>>
>> --srini
>>> +
>>> +    nvmem = devm_nvmem_register(dev, &econfig);
>>> +
>>> +    return PTR_ERR_OR_ZERO(nvmem);
>>> +}
>>> +
>>> +static const struct of_device_id sec_qfprom_of_match[] = {
>>> +    { .compatible = "qcom,sec-qfprom" },
>>> +    {/* sentinel */},
>>> +};
>>> +MODULE_DEVICE_TABLE(of, sec_qfprom_of_match);
>>> +
>>> +static struct platform_driver qfprom_driver = {
>>> +    .probe = sec_qfprom_probe,
>>> +    .driver = {
>>> +        .name = "qcom_sec_qfprom",
>>> +        .of_match_table = sec_qfprom_of_match,
>>> +    },
>>> +};
>>> +module_platform_driver(qfprom_driver);
>>> +MODULE_DESCRIPTION("Qualcomm Secure QFPROM driver");
>>> +MODULE_LICENSE("GPL");
>>> -- 
>>> 2.40.1
>>>