Re: [PATCH v5 2/2] nvmem: sec-qfprom: Add Qualcomm secure QFPROM support

[Mukesh Ojha]

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@xxxxxxxxxxx>
> > ---
> >   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..

-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