From: Ciprian Costea <ciprianmarian.costea@nxp.com>

Provide access to the On Chip One-Time Programmable Controller (OCOTP)
pages on the NXP S32G platform.

Signed-off-by: Ciprian Costea <ciprianmarian.costea@nxp.com>
Co-developed-by: Ghennadi Procopciuc <ghennadi.procopciuc@nxp.com>
Signed-off-by: Ghennadi Procopciuc <ghennadi.procopciuc@nxp.com>
Co-developed-by: Larisa Grigore <larisa.grigore@nxp.com>
Signed-off-by: Larisa Grigore <larisa.grigore@nxp.com>
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
---
v2: Add S-o-b tags for Ghennadi and Larisa.

    Use keepouts instead of the s32g_map[] table.  This allows a bunch
    of code to be deleted.

    Version 1 only let one word (S32G_OCOTP_WORD_SIZE or 4) to be read
    at a time, but now the driver allows larger reads.  Set the
    .word_size in s32g_ocotp_nvmem_config to be 4 instead.

    Krzysztof asked for some changes in the probe() function but that
    code was deleted instead.

 drivers/nvmem/Kconfig            |  10 +++
 drivers/nvmem/Makefile           |   2 +
 drivers/nvmem/s32g-ocotp-nvmem.c | 101 +++++++++++++++++++++++++++++++
 3 files changed, 113 insertions(+)
 create mode 100644 drivers/nvmem/s32g-ocotp-nvmem.c

diff --git a/drivers/nvmem/Kconfig b/drivers/nvmem/Kconfig
index 0bdd86d74f62..55016f803492 100644
--- a/drivers/nvmem/Kconfig
+++ b/drivers/nvmem/Kconfig
@@ -240,6 +240,16 @@ config NVMEM_NINTENDO_OTP
 	  This driver can also be built as a module. If so, the module
 	  will be called nvmem-nintendo-otp.
 
+config NVMEM_S32G_OCOTP
+	tristate "S32G SoC OCOTP support"
+	depends on ARCH_S32
+	help
+	  This is a driver for the 'OCOTP' peripheral available on S32G
+	  platforms.
+
+	  If you say Y here, you will get support for the One Time
+	  Programmable memory pages.
+
 config NVMEM_QCOM_QFPROM
 	tristate "QCOM QFPROM Support"
 	depends on ARCH_QCOM || COMPILE_TEST
diff --git a/drivers/nvmem/Makefile b/drivers/nvmem/Makefile
index 84fef48b7ff6..e01bb4ad612a 100644
--- a/drivers/nvmem/Makefile
+++ b/drivers/nvmem/Makefile
@@ -79,6 +79,8 @@ obj-$(CONFIG_NVMEM_SUNPLUS_OCOTP)	+= nvmem_sunplus_ocotp.o
 nvmem_sunplus_ocotp-y			:= sunplus-ocotp.o
 obj-$(CONFIG_NVMEM_SUNXI_SID)		+= nvmem_sunxi_sid.o
 nvmem_sunxi_sid-y			:= sunxi_sid.o
+obj-$(CONFIG_NVMEM_S32G_OCOTP)		+= nvmem-s32g-ocotp-nvmem.o
+nvmem-s32g-ocotp-nvmem-y		:= s32g-ocotp-nvmem.o
 obj-$(CONFIG_NVMEM_U_BOOT_ENV)		+= nvmem_u-boot-env.o
 nvmem_u-boot-env-y			:= u-boot-env.o
 obj-$(CONFIG_NVMEM_UNIPHIER_EFUSE)	+= nvmem-uniphier-efuse.o
diff --git a/drivers/nvmem/s32g-ocotp-nvmem.c b/drivers/nvmem/s32g-ocotp-nvmem.c
new file mode 100644
index 000000000000..dce092c0fc52
--- /dev/null
+++ b/drivers/nvmem/s32g-ocotp-nvmem.c
@@ -0,0 +1,101 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright 2023-2025 NXP
+ */
+
+#include <linux/device.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/nvmem-provider.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+
+struct s32g_ocotp_priv {
+	struct device *dev;
+	void __iomem *base;
+};
+
+static int s32g_ocotp_read(void *context, unsigned int offset,
+			    void *val, size_t bytes)
+{
+	struct s32g_ocotp_priv *s32g_data = context;
+	u32 *dst = val;
+
+	while (bytes >= sizeof(u32)) {
+		*dst++ = ioread32(s32g_data->base + offset);
+
+		bytes -= sizeof(u32);
+		offset += sizeof(u32);
+	}
+
+	return 0;
+}
+
+static struct nvmem_keepout s32g_keepouts[] = {
+	{ .start = 0,   .end = 520 },
+	{ .start = 540, .end = 564 },
+	{ .start = 596, .end = 664 },
+	{ .start = 668, .end = 676 },
+	{ .start = 684, .end = 732 },
+	{ .start = 744, .end = 864 },
+	{ .start = 908, .end = 924 },
+	{ .start = 928, .end = 936 },
+	{ .start = 948, .end = 964 },
+	{ .start = 968, .end = 976 },
+	{ .start = 984, .end = 1012 },
+};
+
+static struct nvmem_config s32g_ocotp_nvmem_config = {
+	.name = "s32g-ocotp",
+	.add_legacy_fixed_of_cells = true,
+	.read_only = true,
+	.word_size = 4,
+	.reg_read = s32g_ocotp_read,
+	.keepout = s32g_keepouts,
+	.nkeepout = ARRAY_SIZE(s32g_keepouts),
+};
+
+static const struct of_device_id ocotp_of_match[] = {
+	{ .compatible = "nxp,s32g2-ocotp" },
+	{ /* sentinel */ }
+};
+
+static int s32g_ocotp_probe(struct platform_device *pdev)
+{
+	struct s32g_ocotp_priv *s32g_data;
+	struct device *dev = &pdev->dev;
+	struct nvmem_device *nvmem;
+	struct resource *res;
+
+	s32g_data = devm_kzalloc(dev, sizeof(*s32g_data), GFP_KERNEL);
+	if (!s32g_data)
+		return -ENOMEM;
+
+	s32g_data->base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
+	if (IS_ERR(s32g_data->base)) {
+		dev_err(dev, "Cannot map OCOTP device.\n");
+		return PTR_ERR(s32g_data->base);
+	}
+
+	s32g_data->dev = dev;
+	s32g_ocotp_nvmem_config.dev = dev;
+	s32g_ocotp_nvmem_config.priv = s32g_data;
+	s32g_ocotp_nvmem_config.size = resource_size(res);
+
+	nvmem = devm_nvmem_register(dev, &s32g_ocotp_nvmem_config);
+
+	return PTR_ERR_OR_ZERO(nvmem);
+}
+
+static struct platform_driver s32g_ocotp_driver = {
+	.probe = s32g_ocotp_probe,
+	.driver = {
+		.name = "s32g-ocotp",
+		.of_match_table = ocotp_of_match,
+	},
+};
+module_platform_driver(s32g_ocotp_driver);
+MODULE_AUTHOR("NXP");
+MODULE_DESCRIPTION("S32G OCOTP driver");
+MODULE_LICENSE("GPL");
-- 
2.47.2

On Tue, Aug 26, 2025 at 07:38:10PM +0300, Dan Carpenter wrote:
> From: Ciprian Costea <ciprianmarian.costea@nxp.com>
>
> Provide access to the On Chip One-Time Programmable Controller (OCOTP)
> pages on the NXP S32G platform.
>
> Signed-off-by: Ciprian Costea <ciprianmarian.costea@nxp.com>
> Co-developed-by: Ghennadi Procopciuc <ghennadi.procopciuc@nxp.com>
> Signed-off-by: Ghennadi Procopciuc <ghennadi.procopciuc@nxp.com>
> Co-developed-by: Larisa Grigore <larisa.grigore@nxp.com>
> Signed-off-by: Larisa Grigore <larisa.grigore@nxp.com>
> Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
> ---
> v2: Add S-o-b tags for Ghennadi and Larisa.
>
>     Use keepouts instead of the s32g_map[] table.  This allows a bunch
>     of code to be deleted.
>
>     Version 1 only let one word (S32G_OCOTP_WORD_SIZE or 4) to be read
>     at a time, but now the driver allows larger reads.  Set the
>     .word_size in s32g_ocotp_nvmem_config to be 4 instead.
>
>     Krzysztof asked for some changes in the probe() function but that
>     code was deleted instead.
>
>  drivers/nvmem/Kconfig            |  10 +++
>  drivers/nvmem/Makefile           |   2 +
>  drivers/nvmem/s32g-ocotp-nvmem.c | 101 +++++++++++++++++++++++++++++++
>  3 files changed, 113 insertions(+)
>  create mode 100644 drivers/nvmem/s32g-ocotp-nvmem.c
>
> diff --git a/drivers/nvmem/Kconfig b/drivers/nvmem/Kconfig
> index 0bdd86d74f62..55016f803492 100644
> --- a/drivers/nvmem/Kconfig
> +++ b/drivers/nvmem/Kconfig
> @@ -240,6 +240,16 @@ config NVMEM_NINTENDO_OTP
>  	  This driver can also be built as a module. If so, the module
>  	  will be called nvmem-nintendo-otp.
>
...

> +
> +static int s32g_ocotp_read(void *context, unsigned int offset,
> +			    void *val, size_t bytes)
> +{
> +	struct s32g_ocotp_priv *s32g_data = context;
> +	u32 *dst = val;
> +
> +	while (bytes >= sizeof(u32)) {
> +		*dst++ = ioread32(s32g_data->base + offset);
> +
> +		bytes -= sizeof(u32);
> +		offset += sizeof(u32);
> +	}

readsw() ?

> +
> +	return 0;
> +}
> +
> +static struct nvmem_keepout s32g_keepouts[] = {
> +	{ .start = 0,   .end = 520 },
> +	{ .start = 540, .end = 564 },
> +	{ .start = 596, .end = 664 },
> +	{ .start = 668, .end = 676 },
> +	{ .start = 684, .end = 732 },
> +	{ .start = 744, .end = 864 },
> +	{ .start = 908, .end = 924 },
> +	{ .start = 928, .end = 936 },
> +	{ .start = 948, .end = 964 },
> +	{ .start = 968, .end = 976 },
> +	{ .start = 984, .end = 1012 },
> +};
> +
> +static struct nvmem_config s32g_ocotp_nvmem_config = {
> +	.name = "s32g-ocotp",
> +	.add_legacy_fixed_of_cells = true,
> +	.read_only = true,
> +	.word_size = 4,
> +	.reg_read = s32g_ocotp_read,
> +	.keepout = s32g_keepouts,
> +	.nkeepout = ARRAY_SIZE(s32g_keepouts),
> +};
> +
> +static const struct of_device_id ocotp_of_match[] = {
> +	{ .compatible = "nxp,s32g2-ocotp" },
> +	{ /* sentinel */ }
> +};
> +
> +static int s32g_ocotp_probe(struct platform_device *pdev)
> +{
> +	struct s32g_ocotp_priv *s32g_data;
> +	struct device *dev = &pdev->dev;
> +	struct nvmem_device *nvmem;
> +	struct resource *res;
> +
> +	s32g_data = devm_kzalloc(dev, sizeof(*s32g_data), GFP_KERNEL);
> +	if (!s32g_data)
> +		return -ENOMEM;
> +
> +	s32g_data->base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
> +	if (IS_ERR(s32g_data->base)) {
> +		dev_err(dev, "Cannot map OCOTP device.\n");
> +		return PTR_ERR(s32g_data->base);

return dev_err_probe(dev, PTR_ERR(s32g_data->base), ...)

Frank

> +	}
> +
> +	s32g_data->dev = dev;
> +	s32g_ocotp_nvmem_config.dev = dev;
> +	s32g_ocotp_nvmem_config.priv = s32g_data;
> +	s32g_ocotp_nvmem_config.size = resource_size(res);
> +
> +	nvmem = devm_nvmem_register(dev, &s32g_ocotp_nvmem_config);
> +
> +	return PTR_ERR_OR_ZERO(nvmem);
> +}
> +
> +static struct platform_driver s32g_ocotp_driver = {
> +	.probe = s32g_ocotp_probe,
> +	.driver = {
> +		.name = "s32g-ocotp",
> +		.of_match_table = ocotp_of_match,
> +	},
> +};
> +module_platform_driver(s32g_ocotp_driver);
> +MODULE_AUTHOR("NXP");
> +MODULE_DESCRIPTION("S32G OCOTP driver");
> +MODULE_LICENSE("GPL");
> --
> 2.47.2
>

On Wed, Aug 27, 2025 at 12:34:11PM -0400, Frank Li wrote:
> > +static int s32g_ocotp_read(void *context, unsigned int offset,
> > +			    void *val, size_t bytes)
> > +{
> > +	struct s32g_ocotp_priv *s32g_data = context;
> > +	u32 *dst = val;
> > +
> > +	while (bytes >= sizeof(u32)) {
> > +		*dst++ = ioread32(s32g_data->base + offset);
> > +
> > +		bytes -= sizeof(u32);
> > +		offset += sizeof(u32);
> > +	}
> 
> readsw() ?
> 

Hi Frank,

I've learned a lot from your reviews.  Thanks.  :)  It would be readsl()
since it's a u32.  But readsl() doesn't increment the offset, it just
reads from the same memory address over and over.

I've made all the other changes.

regards,
dan carpenter