drivers/nvmem/rockchip-efuse.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Rockchip eFuse Driver
   4  *
   5  * Copyright (c) 2015 Rockchip Electronics Co. Ltd.
   6  * Author: Caesar Wang <wxt@rock-chips.com>
   7  */
   8
   9 #include <linux/clk.h>
  10 #include <linux/delay.h>
  11 #include <linux/device.h>
  12 #include <linux/io.h>
  13 #include <linux/module.h>
  14 #include <linux/nvmem-provider.h>
  15 #include <linux/slab.h>
  16 #include <linux/of.h>
  17 #include <linux/of_platform.h>
  18 #include <linux/platform_device.h>
  19
  20 #define RK3288_A_SHIFT          6
  21 #define RK3288_A_MASK           0x3ff
  22 #define RK3288_PGENB            BIT(3)
  23 #define RK3288_LOAD             BIT(2)
  24 #define RK3288_STROBE           BIT(1)
  25 #define RK3288_CSB              BIT(0)
  26
  27 #define RK3328_SECURE_SIZES     96
  28 #define RK3328_INT_STATUS       0x0018
  29 #define RK3328_DOUT             0x0020
  30 #define RK3328_AUTO_CTRL        0x0024
  31 #define RK3328_INT_FINISH       BIT(0)
  32 #define RK3328_AUTO_ENB         BIT(0)
  33 #define RK3328_AUTO_RD          BIT(1)
  34
  35 #define RK3399_A_SHIFT          16
  36 #define RK3399_A_MASK           0x3ff
  37 #define RK3399_NBYTES           4
  38 #define RK3399_STROBSFTSEL      BIT(9)
  39 #define RK3399_RSB              BIT(7)
  40 #define RK3399_PD               BIT(5)
  41 #define RK3399_PGENB            BIT(3)
  42 #define RK3399_LOAD             BIT(2)
  43 #define RK3399_STROBE           BIT(1)
  44 #define RK3399_CSB              BIT(0)
  45
  46 #define REG_EFUSE_CTRL          0x0000
  47 #define REG_EFUSE_DOUT          0x0004
  48
  49 struct rockchip_efuse_chip {
  50         struct device *dev;
  51         void __iomem *base;
  52         struct clk *clk;
  53 };
  54
  55 static int rockchip_rk3288_efuse_read(void *context, unsigned int offset,
  56                                       void *val, size_t bytes)
  57 {
  58         struct rockchip_efuse_chip *efuse = context;
  59         u8 *buf = val;
  60         int ret;
  61
  62         ret = clk_prepare_enable(efuse->clk);
  63         if (ret < 0) {
  64                 dev_err(efuse->dev, "failed to prepare/enable efuse clk\n");
  65                 return ret;
  66         }
  67
  68         writel(RK3288_LOAD | RK3288_PGENB, efuse->base + REG_EFUSE_CTRL);
  69         udelay(1);
  70         while (bytes--) {
  71                 writel(readl(efuse->base + REG_EFUSE_CTRL) &
  72                              (~(RK3288_A_MASK << RK3288_A_SHIFT)),
  73                              efuse->base + REG_EFUSE_CTRL);
  74                 writel(readl(efuse->base + REG_EFUSE_CTRL) |
  75                              ((offset++ & RK3288_A_MASK) << RK3288_A_SHIFT),
  76                              efuse->base + REG_EFUSE_CTRL);
  77                 udelay(1);
  78                 writel(readl(efuse->base + REG_EFUSE_CTRL) |
  79                              RK3288_STROBE, efuse->base + REG_EFUSE_CTRL);
  80                 udelay(1);
  81                 *buf++ = readb(efuse->base + REG_EFUSE_DOUT);
  82                 writel(readl(efuse->base + REG_EFUSE_CTRL) &
  83                        (~RK3288_STROBE), efuse->base + REG_EFUSE_CTRL);
  84                 udelay(1);
  85         }
  86
  87         /* Switch to standby mode */
  88         writel(RK3288_PGENB | RK3288_CSB, efuse->base + REG_EFUSE_CTRL);
  89
  90         clk_disable_unprepare(efuse->clk);
  91
  92         return 0;
  93 }
  94
  95 static int rockchip_rk3328_efuse_read(void *context, unsigned int offset,
  96                                       void *val, size_t bytes)
  97 {
  98         struct rockchip_efuse_chip *efuse = context;
  99         unsigned int addr_start, addr_end, addr_offset, addr_len;
 100         u32 out_value, status;
 101         u8 *buf;
 102         int ret, i = 0;
 103
 104         ret = clk_prepare_enable(efuse->clk);
 105         if (ret < 0) {
 106                 dev_err(efuse->dev, "failed to prepare/enable efuse clk\n");
 107                 return ret;
 108         }
 109
 110         /* 128 Byte efuse, 96 Byte for secure, 32 Byte for non-secure */
 111         offset += RK3328_SECURE_SIZES;
 112         addr_start = rounddown(offset, RK3399_NBYTES) / RK3399_NBYTES;
 113         addr_end = roundup(offset + bytes, RK3399_NBYTES) / RK3399_NBYTES;
 114         addr_offset = offset % RK3399_NBYTES;
 115         addr_len = addr_end - addr_start;
 116
 117         buf = kzalloc(array3_size(addr_len, RK3399_NBYTES, sizeof(*buf)),
 118                       GFP_KERNEL);
 119         if (!buf) {
 120                 ret = -ENOMEM;
 121                 goto nomem;
 122         }
 123
 124         while (addr_len--) {
 125                 writel(RK3328_AUTO_RD | RK3328_AUTO_ENB |
 126                        ((addr_start++ & RK3399_A_MASK) << RK3399_A_SHIFT),
 127                        efuse->base + RK3328_AUTO_CTRL);
 128                 udelay(4);
 129                 status = readl(efuse->base + RK3328_INT_STATUS);
 130                 if (!(status & RK3328_INT_FINISH)) {
 131                         ret = -EIO;
 132                         goto err;
 133                 }
 134                 out_value = readl(efuse->base + RK3328_DOUT);
 135                 writel(RK3328_INT_FINISH, efuse->base + RK3328_INT_STATUS);
 136
 137                 memcpy(&buf[i], &out_value, RK3399_NBYTES);
 138                 i += RK3399_NBYTES;
 139         }
 140
 141         memcpy(val, buf + addr_offset, bytes);
 142 err:
 143         kfree(buf);
 144 nomem:
 145         clk_disable_unprepare(efuse->clk);
 146
 147         return ret;
 148 }
 149
 150 static int rockchip_rk3399_efuse_read(void *context, unsigned int offset,
 151                                       void *val, size_t bytes)
 152 {
 153         struct rockchip_efuse_chip *efuse = context;
 154         unsigned int addr_start, addr_end, addr_offset, addr_len;
 155         u32 out_value;
 156         u8 *buf;
 157         int ret, i = 0;
 158
 159         ret = clk_prepare_enable(efuse->clk);
 160         if (ret < 0) {
 161                 dev_err(efuse->dev, "failed to prepare/enable efuse clk\n");
 162                 return ret;
 163         }
 164
 165         addr_start = rounddown(offset, RK3399_NBYTES) / RK3399_NBYTES;
 166         addr_end = roundup(offset + bytes, RK3399_NBYTES) / RK3399_NBYTES;
 167         addr_offset = offset % RK3399_NBYTES;
 168         addr_len = addr_end - addr_start;
 169
 170         buf = kzalloc(array3_size(addr_len, RK3399_NBYTES, sizeof(*buf)),
 171                       GFP_KERNEL);
 172         if (!buf) {
 173                 clk_disable_unprepare(efuse->clk);
 174                 return -ENOMEM;
 175         }
 176
 177         writel(RK3399_LOAD | RK3399_PGENB | RK3399_STROBSFTSEL | RK3399_RSB,
 178                efuse->base + REG_EFUSE_CTRL);
 179         udelay(1);
 180         while (addr_len--) {
 181                 writel(readl(efuse->base + REG_EFUSE_CTRL) | RK3399_STROBE |
 182                        ((addr_start++ & RK3399_A_MASK) << RK3399_A_SHIFT),
 183                        efuse->base + REG_EFUSE_CTRL);
 184                 udelay(1);
 185                 out_value = readl(efuse->base + REG_EFUSE_DOUT);
 186                 writel(readl(efuse->base + REG_EFUSE_CTRL) & (~RK3399_STROBE),
 187                        efuse->base + REG_EFUSE_CTRL);
 188                 udelay(1);
 189
 190                 memcpy(&buf[i], &out_value, RK3399_NBYTES);
 191                 i += RK3399_NBYTES;
 192         }
 193
 194         /* Switch to standby mode */
 195         writel(RK3399_PD | RK3399_CSB, efuse->base + REG_EFUSE_CTRL);
 196
 197         memcpy(val, buf + addr_offset, bytes);
 198
 199         kfree(buf);
 200
 201         clk_disable_unprepare(efuse->clk);
 202
 203         return 0;
 204 }
 205
 206 static struct nvmem_config econfig = {
 207         .name = "rockchip-efuse",
 208         .stride = 1,
 209         .word_size = 1,
 210         .read_only = true,
 211 };
 212
 213 static const struct of_device_id rockchip_efuse_match[] = {
 214         /* deprecated but kept around for dts binding compatibility */
 215         {
 216                 .compatible = "rockchip,rockchip-efuse",
 217                 .data = (void *)&rockchip_rk3288_efuse_read,
 218         },
 219         {
 220                 .compatible = "rockchip,rk3066a-efuse",
 221                 .data = (void *)&rockchip_rk3288_efuse_read,
 222         },
 223         {
 224                 .compatible = "rockchip,rk3188-efuse",
 225                 .data = (void *)&rockchip_rk3288_efuse_read,
 226         },
 227         {
 228                 .compatible = "rockchip,rk3228-efuse",
 229                 .data = (void *)&rockchip_rk3288_efuse_read,
 230         },
 231         {
 232                 .compatible = "rockchip,rk3288-efuse",
 233                 .data = (void *)&rockchip_rk3288_efuse_read,
 234         },
 235         {
 236                 .compatible = "rockchip,rk3368-efuse",
 237                 .data = (void *)&rockchip_rk3288_efuse_read,
 238         },
 239         {
 240                 .compatible = "rockchip,rk3328-efuse",
 241                 .data = (void *)&rockchip_rk3328_efuse_read,
 242         },
 243         {
 244                 .compatible = "rockchip,rk3399-efuse",
 245                 .data = (void *)&rockchip_rk3399_efuse_read,
 246         },
 247         { /* sentinel */},
 248 };
 249 MODULE_DEVICE_TABLE(of, rockchip_efuse_match);
 250
 251 static int rockchip_efuse_probe(struct platform_device *pdev)
 252 {
 253         struct resource *res;
 254         struct nvmem_device *nvmem;
 255         struct rockchip_efuse_chip *efuse;
 256         const void *data;
 257         struct device *dev = &pdev->dev;
 258
 259         data = of_device_get_match_data(dev);
 260         if (!data) {
 261                 dev_err(dev, "failed to get match data\n");
 262                 return -EINVAL;
 263         }
 264
 265         efuse = devm_kzalloc(dev, sizeof(struct rockchip_efuse_chip),
 266                              GFP_KERNEL);
 267         if (!efuse)
 268                 return -ENOMEM;
 269
 270         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 271         efuse->base = devm_ioremap_resource(dev, res);
 272         if (IS_ERR(efuse->base))
 273                 return PTR_ERR(efuse->base);
 274
 275         efuse->clk = devm_clk_get(dev, "pclk_efuse");
 276         if (IS_ERR(efuse->clk))
 277                 return PTR_ERR(efuse->clk);
 278
 279         efuse->dev = dev;
 280         if (of_property_read_u32(dev->of_node, "rockchip,efuse-size",
 281                                  &econfig.size))
 282                 econfig.size = resource_size(res);
 283         econfig.reg_read = data;
 284         econfig.priv = efuse;
 285         econfig.dev = efuse->dev;
 286         nvmem = devm_nvmem_register(dev, &econfig);
 287
 288         return PTR_ERR_OR_ZERO(nvmem);
 289 }
 290
 291 static struct platform_driver rockchip_efuse_driver = {
 292         .probe = rockchip_efuse_probe,
 293         .driver = {
 294                 .name = "rockchip-efuse",
 295                 .of_match_table = rockchip_efuse_match,
 296         },
 297 };
 298
 299 module_platform_driver(rockchip_efuse_driver);
 300 MODULE_DESCRIPTION("rockchip_efuse driver");
 301 MODULE_LICENSE("GPL v2");