/* * Copyright (C) 2015 Toradex AG. * * Author: Sanchayan Maity <sanchayan.maity@toradex.com> * * Based on the barebox ocotp driver, * Copyright (c) 2010 Baruch Siach <baruch@tkos.co.il> * Orex Computed Radiography * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 and * only version 2 as published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. */ #include <linux/clk.h> #include <linux/delay.h> #include <linux/device.h> #include <linux/io.h> #include <linux/module.h> #include <linux/nvmem-provider.h> #include <linux/of.h> #include <linux/platform_device.h> #include <linux/slab.h> /* OCOTP Register Offsets */ #define OCOTP_CTRL_REG 0x00 #define OCOTP_CTRL_SET 0x04 #define OCOTP_CTRL_CLR 0x08 #define OCOTP_TIMING 0x10 #define OCOTP_DATA 0x20 #define OCOTP_READ_CTRL_REG 0x30 #define OCOTP_READ_FUSE_DATA 0x40 /* OCOTP Register bits and masks */ #define OCOTP_CTRL_WR_UNLOCK 16 #define OCOTP_CTRL_WR_UNLOCK_KEY 0x3E77 #define OCOTP_CTRL_WR_UNLOCK_MASK GENMASK(31, 16) #define OCOTP_CTRL_ADDR 0 #define OCOTP_CTRL_ADDR_MASK GENMASK(6, 0) #define OCOTP_CTRL_RELOAD_SHADOWS BIT(10) #define OCOTP_CTRL_ERR BIT(9) #define OCOTP_CTRL_BUSY BIT(8) #define OCOTP_TIMING_STROBE_READ 16 #define OCOTP_TIMING_STROBE_READ_MASK GENMASK(21, 16) #define OCOTP_TIMING_RELAX 12 #define OCOTP_TIMING_RELAX_MASK GENMASK(15, 12) #define OCOTP_TIMING_STROBE_PROG 0 #define OCOTP_TIMING_STROBE_PROG_MASK GENMASK(11, 0) #define OCOTP_READ_CTRL_READ_FUSE 0x1 #define VF610_OCOTP_TIMEOUT 100000 #define BF(value, field) (((value) << field) & field##_MASK) #define DEF_RELAX 20 static const int base_to_fuse_addr_mappings[][2] = { {0x400, 0x00}, {0x410, 0x01}, {0x420, 0x02}, {0x450, 0x05}, {0x4F0, 0x0F}, {0x600, 0x20}, {0x610, 0x21}, {0x620, 0x22}, {0x630, 0x23}, {0x640, 0x24}, {0x650, 0x25}, {0x660, 0x26}, {0x670, 0x27}, {0x6F0, 0x2F}, {0x880, 0x38}, {0x890, 0x39}, {0x8A0, 0x3A}, {0x8B0, 0x3B}, {0x8C0, 0x3C}, {0x8D0, 0x3D}, {0x8E0, 0x3E}, {0x8F0, 0x3F}, {0xC80, 0x78}, {0xC90, 0x79}, {0xCA0, 0x7A}, {0xCB0, 0x7B}, {0xCC0, 0x7C}, {0xCD0, 0x7D}, {0xCE0, 0x7E}, {0xCF0, 0x7F}, }; struct vf610_ocotp { void __iomem *base; struct clk *clk; struct device *dev; struct nvmem_device *nvmem; int timing; }; static int vf610_ocotp_wait_busy(void __iomem *base) { int timeout = VF610_OCOTP_TIMEOUT; while ((readl(base) & OCOTP_CTRL_BUSY) && --timeout) udelay(10); if (!timeout) { writel(OCOTP_CTRL_ERR, base + OCOTP_CTRL_CLR); return -ETIMEDOUT; } udelay(10); return 0; } static int vf610_ocotp_calculate_timing(struct vf610_ocotp *ocotp_dev) { u32 clk_rate; u32 relax, strobe_read, strobe_prog; u32 timing; clk_rate = clk_get_rate(ocotp_dev->clk); /* Refer section OTP read/write timing parameters in TRM */ relax = clk_rate / (1000000000 / DEF_RELAX) - 1; strobe_prog = clk_rate / (1000000000 / 10000) + 2 * (DEF_RELAX + 1) - 1; strobe_read = clk_rate / (1000000000 / 40) + 2 * (DEF_RELAX + 1) - 1; timing = BF(relax, OCOTP_TIMING_RELAX); timing |= BF(strobe_read, OCOTP_TIMING_STROBE_READ); timing |= BF(strobe_prog, OCOTP_TIMING_STROBE_PROG); return timing; } static int vf610_get_fuse_address(int base_addr_offset) { int i; for (i = 0; i < ARRAY_SIZE(base_to_fuse_addr_mappings); i++) { if (base_to_fuse_addr_mappings[i][0] == base_addr_offset) return base_to_fuse_addr_mappings[i][1]; } return -EINVAL; } static int vf610_ocotp_read(void *context, unsigned int offset, void *val, size_t bytes) { struct vf610_ocotp *ocotp = context; void __iomem *base = ocotp->base; u32 reg, *buf = val; int fuse_addr; int ret; while (bytes > 0) { fuse_addr = vf610_get_fuse_address(offset); if (fuse_addr > 0) { writel(ocotp->timing, base + OCOTP_TIMING); ret = vf610_ocotp_wait_busy(base + OCOTP_CTRL_REG); if (ret) return ret; reg = readl(base + OCOTP_CTRL_REG); reg &= ~OCOTP_CTRL_ADDR_MASK; reg &= ~OCOTP_CTRL_WR_UNLOCK_MASK; reg |= BF(fuse_addr, OCOTP_CTRL_ADDR); writel(reg, base + OCOTP_CTRL_REG); writel(OCOTP_READ_CTRL_READ_FUSE, base + OCOTP_READ_CTRL_REG); ret = vf610_ocotp_wait_busy(base + OCOTP_CTRL_REG); if (ret) return ret; if (readl(base) & OCOTP_CTRL_ERR) { dev_dbg(ocotp->dev, "Error reading from fuse address %x\n", fuse_addr); writel(OCOTP_CTRL_ERR, base + OCOTP_CTRL_CLR); } /* * In case of error, we do not abort and expect to read * 0xBADABADA as mentioned by the TRM. We just read this * value and return. */ *buf = readl(base + OCOTP_READ_FUSE_DATA); } else { *buf = 0; } buf++; bytes -= 4; offset += 4; } return 0; } static struct nvmem_config ocotp_config = { .name = "ocotp", .owner = THIS_MODULE, .stride = 4, .word_size = 4, .reg_read = vf610_ocotp_read, }; static const struct of_device_id ocotp_of_match[] = { { .compatible = "fsl,vf610-ocotp", }, {/* sentinel */}, }; MODULE_DEVICE_TABLE(of, ocotp_of_match); static int vf610_ocotp_remove(struct platform_device *pdev) { struct vf610_ocotp *ocotp_dev = platform_get_drvdata(pdev); return nvmem_unregister(ocotp_dev->nvmem); } static int vf610_ocotp_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; struct resource *res; struct vf610_ocotp *ocotp_dev; ocotp_dev = devm_kzalloc(&pdev->dev, sizeof(struct vf610_ocotp), GFP_KERNEL); if (!ocotp_dev) return -ENOMEM; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); ocotp_dev->base = devm_ioremap_resource(dev, res); if (IS_ERR(ocotp_dev->base)) return PTR_ERR(ocotp_dev->base); ocotp_dev->clk = devm_clk_get(dev, NULL); if (IS_ERR(ocotp_dev->clk)) { dev_err(dev, "failed getting clock, err = %ld\n", PTR_ERR(ocotp_dev->clk)); return PTR_ERR(ocotp_dev->clk); } ocotp_config.size = resource_size(res); ocotp_config.priv = ocotp_dev; ocotp_config.dev = dev; ocotp_dev->nvmem = nvmem_register(&ocotp_config); if (IS_ERR(ocotp_dev->nvmem)) return PTR_ERR(ocotp_dev->nvmem); ocotp_dev->dev = dev; platform_set_drvdata(pdev, ocotp_dev); ocotp_dev->timing = vf610_ocotp_calculate_timing(ocotp_dev); return 0; } static struct platform_driver vf610_ocotp_driver = { .probe = vf610_ocotp_probe, .remove = vf610_ocotp_remove, .driver = { .name = "vf610-ocotp", .of_match_table = ocotp_of_match, }, }; module_platform_driver(vf610_ocotp_driver); MODULE_AUTHOR("Sanchayan Maity <sanchayan.maity@toradex.com>"); MODULE_DESCRIPTION("Vybrid OCOTP driver"); MODULE_LICENSE("GPL v2");