1 // SPDX-License-Identifier: GPL-2.0 2 // Copyright (C) 2018 Spreadtrum Communications Inc. 3 4 #include <linux/hwspinlock.h> 5 #include <linux/module.h> 6 #include <linux/of.h> 7 #include <linux/platform_device.h> 8 #include <linux/regmap.h> 9 #include <linux/nvmem-provider.h> 10 11 /* PMIC global registers definition */ 12 #define SC27XX_MODULE_EN 0xc08 13 #define SC2730_MODULE_EN 0x1808 14 #define SC27XX_EFUSE_EN BIT(6) 15 16 /* Efuse controller registers definition */ 17 #define SC27XX_EFUSE_GLB_CTRL 0x0 18 #define SC27XX_EFUSE_DATA_RD 0x4 19 #define SC27XX_EFUSE_DATA_WR 0x8 20 #define SC27XX_EFUSE_BLOCK_INDEX 0xc 21 #define SC27XX_EFUSE_MODE_CTRL 0x10 22 #define SC27XX_EFUSE_STATUS 0x14 23 #define SC27XX_EFUSE_WR_TIMING_CTRL 0x20 24 #define SC27XX_EFUSE_RD_TIMING_CTRL 0x24 25 #define SC27XX_EFUSE_EFUSE_DEB_CTRL 0x28 26 27 /* Mask definition for SC27XX_EFUSE_BLOCK_INDEX register */ 28 #define SC27XX_EFUSE_BLOCK_MASK GENMASK(4, 0) 29 30 /* Bits definitions for SC27XX_EFUSE_MODE_CTRL register */ 31 #define SC27XX_EFUSE_PG_START BIT(0) 32 #define SC27XX_EFUSE_RD_START BIT(1) 33 #define SC27XX_EFUSE_CLR_RDDONE BIT(2) 34 35 /* Bits definitions for SC27XX_EFUSE_STATUS register */ 36 #define SC27XX_EFUSE_PGM_BUSY BIT(0) 37 #define SC27XX_EFUSE_READ_BUSY BIT(1) 38 #define SC27XX_EFUSE_STANDBY BIT(2) 39 #define SC27XX_EFUSE_GLOBAL_PROT BIT(3) 40 #define SC27XX_EFUSE_RD_DONE BIT(4) 41 42 /* Block number and block width (bytes) definitions */ 43 #define SC27XX_EFUSE_BLOCK_MAX 32 44 #define SC27XX_EFUSE_BLOCK_WIDTH 2 45 46 /* Timeout (ms) for the trylock of hardware spinlocks */ 47 #define SC27XX_EFUSE_HWLOCK_TIMEOUT 5000 48 49 /* Timeout (us) of polling the status */ 50 #define SC27XX_EFUSE_POLL_TIMEOUT 3000000 51 #define SC27XX_EFUSE_POLL_DELAY_US 10000 52 53 /* 54 * Since different PMICs of SC27xx series can have different 55 * address , we should save address in the device data structure. 56 */ 57 struct sc27xx_efuse_variant_data { 58 u32 module_en; 59 }; 60 61 struct sc27xx_efuse { 62 struct device *dev; 63 struct regmap *regmap; 64 struct hwspinlock *hwlock; 65 struct mutex mutex; 66 u32 base; 67 const struct sc27xx_efuse_variant_data *var_data; 68 }; 69 70 static const struct sc27xx_efuse_variant_data sc2731_edata = { 71 .module_en = SC27XX_MODULE_EN, 72 }; 73 74 static const struct sc27xx_efuse_variant_data sc2730_edata = { 75 .module_en = SC2730_MODULE_EN, 76 }; 77 78 /* 79 * On Spreadtrum platform, we have multi-subsystems will access the unique 80 * efuse controller, so we need one hardware spinlock to synchronize between 81 * the multiple subsystems. 82 */ 83 static int sc27xx_efuse_lock(struct sc27xx_efuse *efuse) 84 { 85 int ret; 86 87 mutex_lock(&efuse->mutex); 88 89 ret = hwspin_lock_timeout_raw(efuse->hwlock, 90 SC27XX_EFUSE_HWLOCK_TIMEOUT); 91 if (ret) { 92 dev_err(efuse->dev, "timeout to get the hwspinlock\n"); 93 mutex_unlock(&efuse->mutex); 94 return ret; 95 } 96 97 return 0; 98 } 99 100 static void sc27xx_efuse_unlock(struct sc27xx_efuse *efuse) 101 { 102 hwspin_unlock_raw(efuse->hwlock); 103 mutex_unlock(&efuse->mutex); 104 } 105 106 static int sc27xx_efuse_poll_status(struct sc27xx_efuse *efuse, u32 bits) 107 { 108 int ret; 109 u32 val; 110 111 ret = regmap_read_poll_timeout(efuse->regmap, 112 efuse->base + SC27XX_EFUSE_STATUS, 113 val, (val & bits), 114 SC27XX_EFUSE_POLL_DELAY_US, 115 SC27XX_EFUSE_POLL_TIMEOUT); 116 if (ret) { 117 dev_err(efuse->dev, "timeout to update the efuse status\n"); 118 return ret; 119 } 120 121 return 0; 122 } 123 124 static int sc27xx_efuse_read(void *context, u32 offset, void *val, size_t bytes) 125 { 126 struct sc27xx_efuse *efuse = context; 127 u32 buf, blk_index = offset / SC27XX_EFUSE_BLOCK_WIDTH; 128 u32 blk_offset = (offset % SC27XX_EFUSE_BLOCK_WIDTH) * BITS_PER_BYTE; 129 int ret; 130 131 if (blk_index > SC27XX_EFUSE_BLOCK_MAX || 132 bytes > SC27XX_EFUSE_BLOCK_WIDTH) 133 return -EINVAL; 134 135 ret = sc27xx_efuse_lock(efuse); 136 if (ret) 137 return ret; 138 139 /* Enable the efuse controller. */ 140 ret = regmap_update_bits(efuse->regmap, efuse->var_data->module_en, 141 SC27XX_EFUSE_EN, SC27XX_EFUSE_EN); 142 if (ret) 143 goto unlock_efuse; 144 145 /* 146 * Before reading, we should ensure the efuse controller is in 147 * standby state. 148 */ 149 ret = sc27xx_efuse_poll_status(efuse, SC27XX_EFUSE_STANDBY); 150 if (ret) 151 goto disable_efuse; 152 153 /* Set the block address to be read. */ 154 ret = regmap_write(efuse->regmap, 155 efuse->base + SC27XX_EFUSE_BLOCK_INDEX, 156 blk_index & SC27XX_EFUSE_BLOCK_MASK); 157 if (ret) 158 goto disable_efuse; 159 160 /* Start reading process from efuse memory. */ 161 ret = regmap_update_bits(efuse->regmap, 162 efuse->base + SC27XX_EFUSE_MODE_CTRL, 163 SC27XX_EFUSE_RD_START, 164 SC27XX_EFUSE_RD_START); 165 if (ret) 166 goto disable_efuse; 167 168 /* 169 * Polling the read done status to make sure the reading process 170 * is completed, that means the data can be read out now. 171 */ 172 ret = sc27xx_efuse_poll_status(efuse, SC27XX_EFUSE_RD_DONE); 173 if (ret) 174 goto disable_efuse; 175 176 /* Read data from efuse memory. */ 177 ret = regmap_read(efuse->regmap, efuse->base + SC27XX_EFUSE_DATA_RD, 178 &buf); 179 if (ret) 180 goto disable_efuse; 181 182 /* Clear the read done flag. */ 183 ret = regmap_update_bits(efuse->regmap, 184 efuse->base + SC27XX_EFUSE_MODE_CTRL, 185 SC27XX_EFUSE_CLR_RDDONE, 186 SC27XX_EFUSE_CLR_RDDONE); 187 188 disable_efuse: 189 /* Disable the efuse controller after reading. */ 190 regmap_update_bits(efuse->regmap, efuse->var_data->module_en, SC27XX_EFUSE_EN, 0); 191 unlock_efuse: 192 sc27xx_efuse_unlock(efuse); 193 194 if (!ret) { 195 buf >>= blk_offset; 196 memcpy(val, &buf, bytes); 197 } 198 199 return ret; 200 } 201 202 static int sc27xx_efuse_probe(struct platform_device *pdev) 203 { 204 struct device_node *np = pdev->dev.of_node; 205 struct nvmem_config econfig = { }; 206 struct nvmem_device *nvmem; 207 struct sc27xx_efuse *efuse; 208 int ret; 209 210 efuse = devm_kzalloc(&pdev->dev, sizeof(*efuse), GFP_KERNEL); 211 if (!efuse) 212 return -ENOMEM; 213 214 efuse->regmap = dev_get_regmap(pdev->dev.parent, NULL); 215 if (!efuse->regmap) { 216 dev_err(&pdev->dev, "failed to get efuse regmap\n"); 217 return -ENODEV; 218 } 219 220 ret = of_property_read_u32(np, "reg", &efuse->base); 221 if (ret) { 222 dev_err(&pdev->dev, "failed to get efuse base address\n"); 223 return ret; 224 } 225 226 ret = of_hwspin_lock_get_id(np, 0); 227 if (ret < 0) { 228 dev_err(&pdev->dev, "failed to get hwspinlock id\n"); 229 return ret; 230 } 231 232 efuse->hwlock = devm_hwspin_lock_request_specific(&pdev->dev, ret); 233 if (!efuse->hwlock) { 234 dev_err(&pdev->dev, "failed to request hwspinlock\n"); 235 return -ENXIO; 236 } 237 238 mutex_init(&efuse->mutex); 239 efuse->dev = &pdev->dev; 240 efuse->var_data = of_device_get_match_data(&pdev->dev); 241 242 econfig.stride = 1; 243 econfig.word_size = 1; 244 econfig.read_only = true; 245 econfig.name = "sc27xx-efuse"; 246 econfig.size = SC27XX_EFUSE_BLOCK_MAX * SC27XX_EFUSE_BLOCK_WIDTH; 247 econfig.reg_read = sc27xx_efuse_read; 248 econfig.priv = efuse; 249 econfig.dev = &pdev->dev; 250 nvmem = devm_nvmem_register(&pdev->dev, &econfig); 251 if (IS_ERR(nvmem)) { 252 dev_err(&pdev->dev, "failed to register nvmem config\n"); 253 return PTR_ERR(nvmem); 254 } 255 256 return 0; 257 } 258 259 static const struct of_device_id sc27xx_efuse_of_match[] = { 260 { .compatible = "sprd,sc2731-efuse", .data = &sc2731_edata}, 261 { .compatible = "sprd,sc2730-efuse", .data = &sc2730_edata}, 262 { } 263 }; 264 265 static struct platform_driver sc27xx_efuse_driver = { 266 .probe = sc27xx_efuse_probe, 267 .driver = { 268 .name = "sc27xx-efuse", 269 .of_match_table = sc27xx_efuse_of_match, 270 }, 271 }; 272 273 module_platform_driver(sc27xx_efuse_driver); 274 275 MODULE_AUTHOR("Freeman Liu <freeman.liu@spreadtrum.com>"); 276 MODULE_DESCRIPTION("Spreadtrum SC27xx efuse driver"); 277 MODULE_LICENSE("GPL v2"); 278