drivers/nvmem/rockchip-otp.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Rockchip OTP Driver
   4  *
   5  * Copyright (c) 2018 Rockchip Electronics Co. Ltd.
   6  * Author: Finley Xiao <finley.xiao@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/iopoll.h>
  14 #include <linux/module.h>
  15 #include <linux/nvmem-provider.h>
  16 #include <linux/reset.h>
  17 #include <linux/slab.h>
  18 #include <linux/of.h>
  19 #include <linux/of_platform.h>
  20 #include <linux/platform_device.h>
  21
  22 /* OTP Register Offsets */
  23 #define OTPC_SBPI_CTRL                  0x0020
  24 #define OTPC_SBPI_CMD_VALID_PRE         0x0024
  25 #define OTPC_SBPI_CS_VALID_PRE          0x0028
  26 #define OTPC_SBPI_STATUS                0x002C
  27 #define OTPC_USER_CTRL                  0x0100
  28 #define OTPC_USER_ADDR                  0x0104
  29 #define OTPC_USER_ENABLE                0x0108
  30 #define OTPC_USER_Q                     0x0124
  31 #define OTPC_INT_STATUS                 0x0304
  32 #define OTPC_SBPI_CMD0_OFFSET           0x1000
  33 #define OTPC_SBPI_CMD1_OFFSET           0x1004
  34
  35 /* OTP Register bits and masks */
  36 #define OTPC_USER_ADDR_MASK             GENMASK(31, 16)
  37 #define OTPC_USE_USER                   BIT(0)
  38 #define OTPC_USE_USER_MASK              GENMASK(16, 16)
  39 #define OTPC_USER_FSM_ENABLE            BIT(0)
  40 #define OTPC_USER_FSM_ENABLE_MASK       GENMASK(16, 16)
  41 #define OTPC_SBPI_DONE                  BIT(1)
  42 #define OTPC_USER_DONE                  BIT(2)
  43
  44 #define SBPI_DAP_ADDR                   0x02
  45 #define SBPI_DAP_ADDR_SHIFT             8
  46 #define SBPI_DAP_ADDR_MASK              GENMASK(31, 24)
  47 #define SBPI_CMD_VALID_MASK             GENMASK(31, 16)
  48 #define SBPI_DAP_CMD_WRF                0xC0
  49 #define SBPI_DAP_REG_ECC                0x3A
  50 #define SBPI_ECC_ENABLE                 0x00
  51 #define SBPI_ECC_DISABLE                0x09
  52 #define SBPI_ENABLE                     BIT(0)
  53 #define SBPI_ENABLE_MASK                GENMASK(16, 16)
  54
  55 #define OTPC_TIMEOUT                    10000
  56
  57 /* RK3588 Register */
  58 #define RK3588_OTPC_AUTO_CTRL           0x04
  59 #define RK3588_OTPC_AUTO_EN             0x08
  60 #define RK3588_OTPC_INT_ST              0x84
  61 #define RK3588_OTPC_DOUT0               0x20
  62 #define RK3588_NO_SECURE_OFFSET         0x300
  63 #define RK3588_NBYTES                   4
  64 #define RK3588_BURST_NUM                1
  65 #define RK3588_BURST_SHIFT              8
  66 #define RK3588_ADDR_SHIFT               16
  67 #define RK3588_AUTO_EN                  BIT(0)
  68 #define RK3588_RD_DONE                  BIT(1)
  69
  70 struct rockchip_data {
  71         int size;
  72         const char * const *clks;
  73         int num_clks;
  74         nvmem_reg_read_t reg_read;
  75 };
  76
  77 struct rockchip_otp {
  78         struct device *dev;
  79         void __iomem *base;
  80         struct clk_bulk_data *clks;
  81         struct reset_control *rst;
  82         const struct rockchip_data *data;
  83 };
  84
  85 static int rockchip_otp_reset(struct rockchip_otp *otp)
  86 {
  87         int ret;
  88
  89         ret = reset_control_assert(otp->rst);
  90         if (ret) {
  91                 dev_err(otp->dev, "failed to assert otp phy %d\n", ret);
  92                 return ret;
  93         }
  94
  95         udelay(2);
  96
  97         ret = reset_control_deassert(otp->rst);
  98         if (ret) {
  99                 dev_err(otp->dev, "failed to deassert otp phy %d\n", ret);
 100                 return ret;
 101         }
 102
 103         return 0;
 104 }
 105
 106 static int rockchip_otp_wait_status(struct rockchip_otp *otp,
 107                                     unsigned int reg, u32 flag)
 108 {
 109         u32 status = 0;
 110         int ret;
 111
 112         ret = readl_poll_timeout_atomic(otp->base + reg, status,
 113                                         (status & flag), 1, OTPC_TIMEOUT);
 114         if (ret)
 115                 return ret;
 116
 117         /* clean int status */
 118         writel(flag, otp->base + reg);
 119
 120         return 0;
 121 }
 122
 123 static int rockchip_otp_ecc_enable(struct rockchip_otp *otp, bool enable)
 124 {
 125         int ret = 0;
 126
 127         writel(SBPI_DAP_ADDR_MASK | (SBPI_DAP_ADDR << SBPI_DAP_ADDR_SHIFT),
 128                otp->base + OTPC_SBPI_CTRL);
 129
 130         writel(SBPI_CMD_VALID_MASK | 0x1, otp->base + OTPC_SBPI_CMD_VALID_PRE);
 131         writel(SBPI_DAP_CMD_WRF | SBPI_DAP_REG_ECC,
 132                otp->base + OTPC_SBPI_CMD0_OFFSET);
 133         if (enable)
 134                 writel(SBPI_ECC_ENABLE, otp->base + OTPC_SBPI_CMD1_OFFSET);
 135         else
 136                 writel(SBPI_ECC_DISABLE, otp->base + OTPC_SBPI_CMD1_OFFSET);
 137
 138         writel(SBPI_ENABLE_MASK | SBPI_ENABLE, otp->base + OTPC_SBPI_CTRL);
 139
 140         ret = rockchip_otp_wait_status(otp, OTPC_INT_STATUS, OTPC_SBPI_DONE);
 141         if (ret < 0)
 142                 dev_err(otp->dev, "timeout during ecc_enable\n");
 143
 144         return ret;
 145 }
 146
 147 static int px30_otp_read(void *context, unsigned int offset,
 148                          void *val, size_t bytes)
 149 {
 150         struct rockchip_otp *otp = context;
 151         u8 *buf = val;
 152         int ret;
 153
 154         ret = rockchip_otp_reset(otp);
 155         if (ret) {
 156                 dev_err(otp->dev, "failed to reset otp phy\n");
 157                 return ret;
 158         }
 159
 160         ret = rockchip_otp_ecc_enable(otp, false);
 161         if (ret < 0) {
 162                 dev_err(otp->dev, "rockchip_otp_ecc_enable err\n");
 163                 return ret;
 164         }
 165
 166         writel(OTPC_USE_USER | OTPC_USE_USER_MASK, otp->base + OTPC_USER_CTRL);
 167         udelay(5);
 168         while (bytes--) {
 169                 writel(offset++ | OTPC_USER_ADDR_MASK,
 170                        otp->base + OTPC_USER_ADDR);
 171                 writel(OTPC_USER_FSM_ENABLE | OTPC_USER_FSM_ENABLE_MASK,
 172                        otp->base + OTPC_USER_ENABLE);
 173                 ret = rockchip_otp_wait_status(otp, OTPC_INT_STATUS, OTPC_USER_DONE);
 174                 if (ret < 0) {
 175                         dev_err(otp->dev, "timeout during read setup\n");
 176                         goto read_end;
 177                 }
 178                 *buf++ = readb(otp->base + OTPC_USER_Q);
 179         }
 180
 181 read_end:
 182         writel(0x0 | OTPC_USE_USER_MASK, otp->base + OTPC_USER_CTRL);
 183
 184         return ret;
 185 }
 186
 187 static int rk3588_otp_read(void *context, unsigned int offset,
 188                            void *val, size_t bytes)
 189 {
 190         struct rockchip_otp *otp = context;
 191         unsigned int addr_start, addr_end, addr_len;
 192         int ret, i = 0;
 193         u32 data;
 194         u8 *buf;
 195
 196         addr_start = round_down(offset, RK3588_NBYTES) / RK3588_NBYTES;
 197         addr_end = round_up(offset + bytes, RK3588_NBYTES) / RK3588_NBYTES;
 198         addr_len = addr_end - addr_start;
 199         addr_start += RK3588_NO_SECURE_OFFSET;
 200
 201         buf = kzalloc(array_size(addr_len, RK3588_NBYTES), GFP_KERNEL);
 202         if (!buf)
 203                 return -ENOMEM;
 204
 205         while (addr_len--) {
 206                 writel((addr_start << RK3588_ADDR_SHIFT) |
 207                        (RK3588_BURST_NUM << RK3588_BURST_SHIFT),
 208                        otp->base + RK3588_OTPC_AUTO_CTRL);
 209                 writel(RK3588_AUTO_EN, otp->base + RK3588_OTPC_AUTO_EN);
 210
 211                 ret = rockchip_otp_wait_status(otp, RK3588_OTPC_INT_ST,
 212                                                RK3588_RD_DONE);
 213                 if (ret < 0) {
 214                         dev_err(otp->dev, "timeout during read setup\n");
 215                         goto read_end;
 216                 }
 217
 218                 data = readl(otp->base + RK3588_OTPC_DOUT0);
 219                 memcpy(&buf[i], &data, RK3588_NBYTES);
 220
 221                 i += RK3588_NBYTES;
 222                 addr_start++;
 223         }
 224
 225         memcpy(val, buf + offset % RK3588_NBYTES, bytes);
 226
 227 read_end:
 228         kfree(buf);
 229
 230         return ret;
 231 }
 232
 233 static int rockchip_otp_read(void *context, unsigned int offset,
 234                              void *val, size_t bytes)
 235 {
 236         struct rockchip_otp *otp = context;
 237         int ret;
 238
 239         if (!otp->data || !otp->data->reg_read)
 240                 return -EINVAL;
 241
 242         ret = clk_bulk_prepare_enable(otp->data->num_clks, otp->clks);
 243         if (ret < 0) {
 244                 dev_err(otp->dev, "failed to prepare/enable clks\n");
 245                 return ret;
 246         }
 247
 248         ret = otp->data->reg_read(context, offset, val, bytes);
 249
 250         clk_bulk_disable_unprepare(otp->data->num_clks, otp->clks);
 251
 252         return ret;
 253 }
 254
 255 static struct nvmem_config otp_config = {
 256         .name = "rockchip-otp",
 257         .owner = THIS_MODULE,
 258         .read_only = true,
 259         .stride = 1,
 260         .word_size = 1,
 261         .reg_read = rockchip_otp_read,
 262 };
 263
 264 static const char * const px30_otp_clocks[] = {
 265         "otp", "apb_pclk", "phy",
 266 };
 267
 268 static const struct rockchip_data px30_data = {
 269         .size = 0x40,
 270         .clks = px30_otp_clocks,
 271         .num_clks = ARRAY_SIZE(px30_otp_clocks),
 272         .reg_read = px30_otp_read,
 273 };
 274
 275 static const char * const rk3588_otp_clocks[] = {
 276         "otp", "apb_pclk", "phy", "arb",
 277 };
 278
 279 static const struct rockchip_data rk3588_data = {
 280         .size = 0x400,
 281         .clks = rk3588_otp_clocks,
 282         .num_clks = ARRAY_SIZE(rk3588_otp_clocks),
 283         .reg_read = rk3588_otp_read,
 284 };
 285
 286 static const struct of_device_id rockchip_otp_match[] = {
 287         {
 288                 .compatible = "rockchip,px30-otp",
 289                 .data = &px30_data,
 290         },
 291         {
 292                 .compatible = "rockchip,rk3308-otp",
 293                 .data = &px30_data,
 294         },
 295         {
 296                 .compatible = "rockchip,rk3588-otp",
 297                 .data = &rk3588_data,
 298         },
 299         { /* sentinel */ },
 300 };
 301 MODULE_DEVICE_TABLE(of, rockchip_otp_match);
 302
 303 static int rockchip_otp_probe(struct platform_device *pdev)
 304 {
 305         struct device *dev = &pdev->dev;
 306         struct rockchip_otp *otp;
 307         const struct rockchip_data *data;
 308         struct nvmem_device *nvmem;
 309         int ret, i;
 310
 311         data = of_device_get_match_data(dev);
 312         if (!data)
 313                 return dev_err_probe(dev, -EINVAL, "failed to get match data\n");
 314
 315         otp = devm_kzalloc(&pdev->dev, sizeof(struct rockchip_otp),
 316                            GFP_KERNEL);
 317         if (!otp)
 318                 return -ENOMEM;
 319
 320         otp->data = data;
 321         otp->dev = dev;
 322         otp->base = devm_platform_ioremap_resource(pdev, 0);
 323         if (IS_ERR(otp->base))
 324                 return dev_err_probe(dev, PTR_ERR(otp->base),
 325                                      "failed to ioremap resource\n");
 326
 327         otp->clks = devm_kcalloc(dev, data->num_clks, sizeof(*otp->clks),
 328                                  GFP_KERNEL);
 329         if (!otp->clks)
 330                 return -ENOMEM;
 331
 332         for (i = 0; i < data->num_clks; ++i)
 333                 otp->clks[i].id = data->clks[i];
 334
 335         ret = devm_clk_bulk_get(dev, data->num_clks, otp->clks);
 336         if (ret)
 337                 return dev_err_probe(dev, ret, "failed to get clocks\n");
 338
 339         otp->rst = devm_reset_control_array_get_exclusive(dev);
 340         if (IS_ERR(otp->rst))
 341                 return dev_err_probe(dev, PTR_ERR(otp->rst),
 342                                      "failed to get resets\n");
 343
 344         otp_config.size = data->size;
 345         otp_config.priv = otp;
 346         otp_config.dev = dev;
 347
 348         nvmem = devm_nvmem_register(dev, &otp_config);
 349         if (IS_ERR(nvmem))
 350                 return dev_err_probe(dev, PTR_ERR(nvmem),
 351                                      "failed to register nvmem device\n");
 352         return 0;
 353 }
 354
 355 static struct platform_driver rockchip_otp_driver = {
 356         .probe = rockchip_otp_probe,
 357         .driver = {
 358                 .name = "rockchip-otp",
 359                 .of_match_table = rockchip_otp_match,
 360         },
 361 };
 362
 363 module_platform_driver(rockchip_otp_driver);
 364 MODULE_DESCRIPTION("Rockchip OTP driver");
 365 MODULE_LICENSE("GPL v2");