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| Commit | Line | Data |
|---|---|---|
| 88806daf JE |
1 | /* |
| 2 | * NXP LPC18xx/43xx OTP memory NVMEM driver | |
| 3 | * | |
| 4 | * Copyright (c) 2016 Joachim Eastwood <manabian@gmail.com> | |
| 5 | * | |
| 6 | * Based on the imx ocotp driver, | |
| 7 | * Copyright (c) 2015 Pengutronix, Philipp Zabel <p.zabel@pengutronix.de> | |
| 8 | * | |
| 9 | * This program is free software; you can redistribute it and/or modify | |
| 10 | * it under the terms of the GNU General Public License version 2 | |
| 11 | * as published by the Free Software Foundation. | |
| 12 | * | |
| 13 | * TODO: add support for writing OTP register via API in boot ROM. | |
| 14 | */ | |
| 15 | ||
| 16 | #include <linux/io.h> | |
| 17 | #include <linux/module.h> | |
| 18 | #include <linux/nvmem-provider.h> | |
| 19 | #include <linux/of.h> | |
| 20 | #include <linux/of_device.h> | |
| 21 | #include <linux/platform_device.h> | |
| 22 | #include <linux/slab.h> | |
| 23 | ||
| 24 | /* | |
| 25 | * LPC18xx OTP memory contains 4 banks with 4 32-bit words. Bank 0 starts | |
| 26 | * at offset 0 from the base. | |
| 27 | * | |
| 28 | * Bank 0 contains the part ID for Flashless devices and is reseverd for | |
| 29 | * devices with Flash. | |
| 30 | * Bank 1/2 is generale purpose or AES key storage for secure devices. | |
| 31 | * Bank 3 contains control data, USB ID and generale purpose words. | |
| 32 | */ | |
| 33 | #define LPC18XX_OTP_NUM_BANKS 4 | |
| 34 | #define LPC18XX_OTP_WORDS_PER_BANK 4 | |
| 35 | #define LPC18XX_OTP_WORD_SIZE sizeof(u32) | |
| 36 | #define LPC18XX_OTP_SIZE (LPC18XX_OTP_NUM_BANKS * \ | |
| 37 | LPC18XX_OTP_WORDS_PER_BANK * \ | |
| 38 | LPC18XX_OTP_WORD_SIZE) | |
| 39 | ||
| 40 | struct lpc18xx_otp { | |
| 41 | void __iomem *base; | |
| 42 | }; | |
| 43 | ||
| 44 | static int lpc18xx_otp_read(void *context, unsigned int offset, | |
| 45 | void *val, size_t bytes) | |
| 46 | { | |
| 47 | struct lpc18xx_otp *otp = context; | |
| 48 | unsigned int count = bytes >> 2; | |
| 49 | u32 index = offset >> 2; | |
| 50 | u32 *buf = val; | |
| 51 | int i; | |
| 52 | ||
| 53 | if (count > (LPC18XX_OTP_SIZE - index)) | |
| 54 | count = LPC18XX_OTP_SIZE - index; | |
| 55 | ||
| 56 | for (i = index; i < (index + count); i++) | |
| 57 | *buf++ = readl(otp->base + i * LPC18XX_OTP_WORD_SIZE); | |
| 58 | ||
| 59 | return 0; | |
| 60 | } | |
| 61 | ||
| 62 | static struct nvmem_config lpc18xx_otp_nvmem_config = { | |
| 63 | .name = "lpc18xx-otp", | |
| 64 | .read_only = true, | |
| 65 | .word_size = LPC18XX_OTP_WORD_SIZE, | |
| 66 | .stride = LPC18XX_OTP_WORD_SIZE, | |
| 88806daf JE |
67 | .reg_read = lpc18xx_otp_read, |
| 68 | }; | |
| 69 | ||
| 70 | static int lpc18xx_otp_probe(struct platform_device *pdev) | |
| 71 | { | |
| 72 | struct nvmem_device *nvmem; | |
| 73 | struct lpc18xx_otp *otp; | |
| 74 | struct resource *res; | |
| 75 | ||
| 76 | otp = devm_kzalloc(&pdev->dev, sizeof(*otp), GFP_KERNEL); | |
| 77 | if (!otp) | |
| 78 | return -ENOMEM; | |
| 79 | ||
| 80 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
| 81 | otp->base = devm_ioremap_resource(&pdev->dev, res); | |
| 82 | if (IS_ERR(otp->base)) | |
| 83 | return PTR_ERR(otp->base); | |
| 84 | ||
| 85 | lpc18xx_otp_nvmem_config.size = LPC18XX_OTP_SIZE; | |
| 86 | lpc18xx_otp_nvmem_config.dev = &pdev->dev; | |
| 87 | lpc18xx_otp_nvmem_config.priv = otp; | |
| 88 | ||
| b005b2f5 | 89 | nvmem = devm_nvmem_register(&pdev->dev, &lpc18xx_otp_nvmem_config); |
| 88806daf | 90 | |
| b005b2f5 | 91 | return PTR_ERR_OR_ZERO(nvmem); |
| 88806daf JE |
92 | } |
| 93 | ||
| 94 | static const struct of_device_id lpc18xx_otp_dt_ids[] = { | |
| 95 | { .compatible = "nxp,lpc1850-otp" }, | |
| 96 | { }, | |
| 97 | }; | |
| 98 | MODULE_DEVICE_TABLE(of, lpc18xx_otp_dt_ids); | |
| 99 | ||
| 100 | static struct platform_driver lpc18xx_otp_driver = { | |
| 101 | .probe = lpc18xx_otp_probe, | |
| 88806daf JE |
102 | .driver = { |
| 103 | .name = "lpc18xx_otp", | |
| 104 | .of_match_table = lpc18xx_otp_dt_ids, | |
| 105 | }, | |
| 106 | }; | |
| 107 | module_platform_driver(lpc18xx_otp_driver); | |
| 108 | ||
| 109 | MODULE_AUTHOR("Joachim Eastwoood <manabian@gmail.com>"); | |
| 110 | MODULE_DESCRIPTION("NXP LPC18xx OTP NVMEM driver"); | |
| 111 | MODULE_LICENSE("GPL v2"); |