nvmem: s32g-ocotp: Add driver for S32G OCOTP

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

Signed-off-by: Ciprian Costea <[e-mail]>
Co-developed-by: Ghennadi Procopciuc <[e-mail]>
Signed-off-by: Ghennadi Procopciuc <[e-mail]>
Co-developed-by: Larisa Grigore <[e-mail]>
Signed-off-by: Larisa Grigore <[e-mail]>
Signed-off-by: Dan Carpenter <[e-mail]>
Signed-off-by: Srinivas Kandagatla <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/nvmem/Kconfig

···
 	  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

drivers/nvmem/Makefile

···
 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

drivers/nvmem/s32g-ocotp-nvmem.c

···
+// 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))
+		return dev_err_probe(dev, PTR_ERR(s32g_data->base),
+				     "Cannot map OCOTP device.\n");
+
+	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");