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

[Srinivas Kandagatla]

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.


--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