// SPDX-License-Identifier: GPL-2.0-only /* * NXP LPC18xx/43xx OTP memory NVMEM driver * * Copyright (c) 2016 Joachim Eastwood <manabian@gmail.com> * * Based on the imx ocotp driver, * Copyright (c) 2015 Pengutronix, Philipp Zabel <p.zabel@pengutronix.de> * * TODO: add support for writing OTP register via API in boot ROM. */ #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> #include <linux/slab.h> /* * LPC18xx OTP memory contains 4 banks with 4 32-bit words. Bank 0 starts * at offset 0 from the base. * * Bank 0 contains the part ID for Flashless devices and is reseverd for * devices with Flash. * Bank 1/2 is generale purpose or AES key storage for secure devices. * Bank 3 contains control data, USB ID and generale purpose words. */ #define LPC18XX_OTP_NUM_BANKS 4 #define LPC18XX_OTP_WORDS_PER_BANK 4 #define LPC18XX_OTP_WORD_SIZE sizeof(u32) #define LPC18XX_OTP_SIZE (LPC18XX_OTP_NUM_BANKS * \ LPC18XX_OTP_WORDS_PER_BANK * \ LPC18XX_OTP_WORD_SIZE) struct lpc18xx_otp { void __iomem *base; }; static int lpc18xx_otp_read(void *context, unsigned int offset, void *val, size_t bytes) { struct lpc18xx_otp *otp = context; unsigned int count = bytes >> 2; u32 index = offset >> 2; u32 *buf = val; int i; if (count > (LPC18XX_OTP_SIZE - index)) count = LPC18XX_OTP_SIZE - index; for (i = index; i < (index + count); i++) *buf++ = readl(otp->base + i * LPC18XX_OTP_WORD_SIZE); return 0; } static struct nvmem_config lpc18xx_otp_nvmem_config = { .name = "lpc18xx-otp", .read_only = true, .word_size = LPC18XX_OTP_WORD_SIZE, .stride = LPC18XX_OTP_WORD_SIZE, .reg_read = lpc18xx_otp_read, }; static int lpc18xx_otp_probe(struct platform_device *pdev) { struct nvmem_device *nvmem; struct lpc18xx_otp *otp; struct resource *res; otp = devm_kzalloc(&pdev->dev, sizeof(*otp), GFP_KERNEL); if (!otp) return -ENOMEM; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); otp->base = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(otp->base)) return PTR_ERR(otp->base); lpc18xx_otp_nvmem_config.size = LPC18XX_OTP_SIZE; lpc18xx_otp_nvmem_config.dev = &pdev->dev; lpc18xx_otp_nvmem_config.priv = otp; nvmem = devm_nvmem_register(&pdev->dev, &lpc18xx_otp_nvmem_config); return PTR_ERR_OR_ZERO(nvmem); } static const struct of_device_id lpc18xx_otp_dt_ids[] = { { .compatible = "nxp,lpc1850-otp" }, { }, }; MODULE_DEVICE_TABLE(of, lpc18xx_otp_dt_ids); static struct platform_driver lpc18xx_otp_driver = { .probe = lpc18xx_otp_probe, .driver = { .name = "lpc18xx_otp", .of_match_table = lpc18xx_otp_dt_ids, }, }; module_platform_driver(lpc18xx_otp_driver); MODULE_AUTHOR("Joachim Eastwoood <manabian@gmail.com>"); MODULE_DESCRIPTION("NXP LPC18xx OTP NVMEM driver"); MODULE_LICENSE("GPL v2");