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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Copyright (C) 2015 Toradex AG.4 *5 * Author: Sanchayan Maity <sanchayan.maity@toradex.com>6 *7 * Based on the barebox ocotp driver,8 * Copyright (c) 2010 Baruch Siach <baruch@tkos.co.il>9 * Orex Computed Radiography10 */11 12#include <linux/clk.h>13#include <linux/delay.h>14#include <linux/device.h>15#include <linux/io.h>16#include <linux/module.h>17#include <linux/nvmem-provider.h>18#include <linux/of.h>19#include <linux/platform_device.h>20#include <linux/slab.h>21 22/* OCOTP Register Offsets */23#define OCOTP_CTRL_REG 0x0024#define OCOTP_CTRL_SET 0x0425#define OCOTP_CTRL_CLR 0x0826#define OCOTP_TIMING 0x1027#define OCOTP_DATA 0x2028#define OCOTP_READ_CTRL_REG 0x3029#define OCOTP_READ_FUSE_DATA 0x4030 31/* OCOTP Register bits and masks */32#define OCOTP_CTRL_WR_UNLOCK 1633#define OCOTP_CTRL_WR_UNLOCK_KEY 0x3E7734#define OCOTP_CTRL_WR_UNLOCK_MASK GENMASK(31, 16)35#define OCOTP_CTRL_ADDR 036#define OCOTP_CTRL_ADDR_MASK GENMASK(6, 0)37#define OCOTP_CTRL_RELOAD_SHADOWS BIT(10)38#define OCOTP_CTRL_ERR BIT(9)39#define OCOTP_CTRL_BUSY BIT(8)40 41#define OCOTP_TIMING_STROBE_READ 1642#define OCOTP_TIMING_STROBE_READ_MASK GENMASK(21, 16)43#define OCOTP_TIMING_RELAX 1244#define OCOTP_TIMING_RELAX_MASK GENMASK(15, 12)45#define OCOTP_TIMING_STROBE_PROG 046#define OCOTP_TIMING_STROBE_PROG_MASK GENMASK(11, 0)47 48#define OCOTP_READ_CTRL_READ_FUSE 0x149 50#define VF610_OCOTP_TIMEOUT 10000051 52#define BF(value, field) (((value) << field) & field##_MASK)53 54#define DEF_RELAX 2055 56static const int base_to_fuse_addr_mappings[][2] = {57 {0x400, 0x00},58 {0x410, 0x01},59 {0x420, 0x02},60 {0x450, 0x05},61 {0x4F0, 0x0F},62 {0x600, 0x20},63 {0x610, 0x21},64 {0x620, 0x22},65 {0x630, 0x23},66 {0x640, 0x24},67 {0x650, 0x25},68 {0x660, 0x26},69 {0x670, 0x27},70 {0x6F0, 0x2F},71 {0x880, 0x38},72 {0x890, 0x39},73 {0x8A0, 0x3A},74 {0x8B0, 0x3B},75 {0x8C0, 0x3C},76 {0x8D0, 0x3D},77 {0x8E0, 0x3E},78 {0x8F0, 0x3F},79 {0xC80, 0x78},80 {0xC90, 0x79},81 {0xCA0, 0x7A},82 {0xCB0, 0x7B},83 {0xCC0, 0x7C},84 {0xCD0, 0x7D},85 {0xCE0, 0x7E},86 {0xCF0, 0x7F},87};88 89struct vf610_ocotp {90 void __iomem *base;91 struct clk *clk;92 struct device *dev;93 struct nvmem_device *nvmem;94 int timing;95};96 97static int vf610_ocotp_wait_busy(void __iomem *base)98{99 int timeout = VF610_OCOTP_TIMEOUT;100 101 while ((readl(base) & OCOTP_CTRL_BUSY) && --timeout)102 udelay(10);103 104 if (!timeout) {105 writel(OCOTP_CTRL_ERR, base + OCOTP_CTRL_CLR);106 return -ETIMEDOUT;107 }108 109 udelay(10);110 111 return 0;112}113 114static int vf610_ocotp_calculate_timing(struct vf610_ocotp *ocotp_dev)115{116 u32 clk_rate;117 u32 relax, strobe_read, strobe_prog;118 u32 timing;119 120 clk_rate = clk_get_rate(ocotp_dev->clk);121 122 /* Refer section OTP read/write timing parameters in TRM */123 relax = clk_rate / (1000000000 / DEF_RELAX) - 1;124 strobe_prog = clk_rate / (1000000000 / 10000) + 2 * (DEF_RELAX + 1) - 1;125 strobe_read = clk_rate / (1000000000 / 40) + 2 * (DEF_RELAX + 1) - 1;126 127 timing = BF(relax, OCOTP_TIMING_RELAX);128 timing |= BF(strobe_read, OCOTP_TIMING_STROBE_READ);129 timing |= BF(strobe_prog, OCOTP_TIMING_STROBE_PROG);130 131 return timing;132}133 134static int vf610_get_fuse_address(int base_addr_offset)135{136 int i;137 138 for (i = 0; i < ARRAY_SIZE(base_to_fuse_addr_mappings); i++) {139 if (base_to_fuse_addr_mappings[i][0] == base_addr_offset)140 return base_to_fuse_addr_mappings[i][1];141 }142 143 return -EINVAL;144}145 146static int vf610_ocotp_read(void *context, unsigned int offset,147 void *val, size_t bytes)148{149 struct vf610_ocotp *ocotp = context;150 void __iomem *base = ocotp->base;151 u32 reg, *buf = val;152 int fuse_addr;153 int ret;154 155 while (bytes > 0) {156 fuse_addr = vf610_get_fuse_address(offset);157 if (fuse_addr > 0) {158 writel(ocotp->timing, base + OCOTP_TIMING);159 ret = vf610_ocotp_wait_busy(base + OCOTP_CTRL_REG);160 if (ret)161 return ret;162 163 reg = readl(base + OCOTP_CTRL_REG);164 reg &= ~OCOTP_CTRL_ADDR_MASK;165 reg &= ~OCOTP_CTRL_WR_UNLOCK_MASK;166 reg |= BF(fuse_addr, OCOTP_CTRL_ADDR);167 writel(reg, base + OCOTP_CTRL_REG);168 169 writel(OCOTP_READ_CTRL_READ_FUSE,170 base + OCOTP_READ_CTRL_REG);171 ret = vf610_ocotp_wait_busy(base + OCOTP_CTRL_REG);172 if (ret)173 return ret;174 175 if (readl(base) & OCOTP_CTRL_ERR) {176 dev_dbg(ocotp->dev, "Error reading from fuse address %x\n",177 fuse_addr);178 writel(OCOTP_CTRL_ERR, base + OCOTP_CTRL_CLR);179 }180 181 /*182 * In case of error, we do not abort and expect to read183 * 0xBADABADA as mentioned by the TRM. We just read this184 * value and return.185 */186 *buf = readl(base + OCOTP_READ_FUSE_DATA);187 } else {188 *buf = 0;189 }190 191 buf++;192 bytes -= 4;193 offset += 4;194 }195 196 return 0;197}198 199static struct nvmem_config ocotp_config = {200 .name = "ocotp",201 .stride = 4,202 .word_size = 4,203 .reg_read = vf610_ocotp_read,204};205 206static const struct of_device_id ocotp_of_match[] = {207 { .compatible = "fsl,vf610-ocotp", },208 {/* sentinel */},209};210MODULE_DEVICE_TABLE(of, ocotp_of_match);211 212static int vf610_ocotp_probe(struct platform_device *pdev)213{214 struct device *dev = &pdev->dev;215 struct resource *res;216 struct vf610_ocotp *ocotp_dev;217 218 ocotp_dev = devm_kzalloc(dev, sizeof(struct vf610_ocotp), GFP_KERNEL);219 if (!ocotp_dev)220 return -ENOMEM;221 222 ocotp_dev->base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);223 if (IS_ERR(ocotp_dev->base))224 return PTR_ERR(ocotp_dev->base);225 226 ocotp_dev->clk = devm_clk_get(dev, NULL);227 if (IS_ERR(ocotp_dev->clk)) {228 dev_err(dev, "failed getting clock, err = %ld\n",229 PTR_ERR(ocotp_dev->clk));230 return PTR_ERR(ocotp_dev->clk);231 }232 ocotp_dev->dev = dev;233 ocotp_dev->timing = vf610_ocotp_calculate_timing(ocotp_dev);234 235 ocotp_config.size = resource_size(res);236 ocotp_config.priv = ocotp_dev;237 ocotp_config.dev = dev;238 239 ocotp_dev->nvmem = devm_nvmem_register(dev, &ocotp_config);240 241 return PTR_ERR_OR_ZERO(ocotp_dev->nvmem);242}243 244static struct platform_driver vf610_ocotp_driver = {245 .probe = vf610_ocotp_probe,246 .driver = {247 .name = "vf610-ocotp",248 .of_match_table = ocotp_of_match,249 },250};251module_platform_driver(vf610_ocotp_driver);252MODULE_AUTHOR("Sanchayan Maity <sanchayan.maity@toradex.com>");253MODULE_DESCRIPTION("Vybrid OCOTP driver");254MODULE_LICENSE("GPL v2");255