// SPDX-License-Identifier: GPL-2.0 // Copyright (C) 2018 Spreadtrum Communications Inc. #include #include #include #include #include #include #include /* PMIC global registers definition */ #define SC27XX_MODULE_EN 0xc08 #define SC2730_MODULE_EN 0x1808 #define SC27XX_EFUSE_EN BIT(6) /* Efuse controller registers definition */ #define SC27XX_EFUSE_GLB_CTRL 0x0 #define SC27XX_EFUSE_DATA_RD 0x4 #define SC27XX_EFUSE_DATA_WR 0x8 #define SC27XX_EFUSE_BLOCK_INDEX 0xc #define SC27XX_EFUSE_MODE_CTRL 0x10 #define SC27XX_EFUSE_STATUS 0x14 #define SC27XX_EFUSE_WR_TIMING_CTRL 0x20 #define SC27XX_EFUSE_RD_TIMING_CTRL 0x24 #define SC27XX_EFUSE_EFUSE_DEB_CTRL 0x28 /* Mask definition for SC27XX_EFUSE_BLOCK_INDEX register */ #define SC27XX_EFUSE_BLOCK_MASK GENMASK(4, 0) /* Bits definitions for SC27XX_EFUSE_MODE_CTRL register */ #define SC27XX_EFUSE_PG_START BIT(0) #define SC27XX_EFUSE_RD_START BIT(1) #define SC27XX_EFUSE_CLR_RDDONE BIT(2) /* Bits definitions for SC27XX_EFUSE_STATUS register */ #define SC27XX_EFUSE_PGM_BUSY BIT(0) #define SC27XX_EFUSE_READ_BUSY BIT(1) #define SC27XX_EFUSE_STANDBY BIT(2) #define SC27XX_EFUSE_GLOBAL_PROT BIT(3) #define SC27XX_EFUSE_RD_DONE BIT(4) /* Block number and block width (bytes) definitions */ #define SC27XX_EFUSE_BLOCK_MAX 32 #define SC27XX_EFUSE_BLOCK_WIDTH 2 /* Timeout (ms) for the trylock of hardware spinlocks */ #define SC27XX_EFUSE_HWLOCK_TIMEOUT 5000 /* Timeout (us) of polling the status */ #define SC27XX_EFUSE_POLL_TIMEOUT 3000000 #define SC27XX_EFUSE_POLL_DELAY_US 10000 /* * Since different PMICs of SC27xx series can have different * address , we should save address in the device data structure. */ struct sc27xx_efuse_variant_data { u32 module_en; }; struct sc27xx_efuse { struct device *dev; struct regmap *regmap; struct hwspinlock *hwlock; struct mutex mutex; u32 base; const struct sc27xx_efuse_variant_data *var_data; }; static const struct sc27xx_efuse_variant_data sc2731_edata = { .module_en = SC27XX_MODULE_EN, }; static const struct sc27xx_efuse_variant_data sc2730_edata = { .module_en = SC2730_MODULE_EN, }; /* * On Spreadtrum platform, we have multi-subsystems will access the unique * efuse controller, so we need one hardware spinlock to synchronize between * the multiple subsystems. */ static int sc27xx_efuse_lock(struct sc27xx_efuse *efuse) { int ret; mutex_lock(&efuse->mutex); ret = hwspin_lock_timeout_raw(efuse->hwlock, SC27XX_EFUSE_HWLOCK_TIMEOUT); if (ret) { dev_err(efuse->dev, "timeout to get the hwspinlock\n"); mutex_unlock(&efuse->mutex); return ret; } return 0; } static void sc27xx_efuse_unlock(struct sc27xx_efuse *efuse) { hwspin_unlock_raw(efuse->hwlock); mutex_unlock(&efuse->mutex); } static int sc27xx_efuse_poll_status(struct sc27xx_efuse *efuse, u32 bits) { int ret; u32 val; ret = regmap_read_poll_timeout(efuse->regmap, efuse->base + SC27XX_EFUSE_STATUS, val, (val & bits), SC27XX_EFUSE_POLL_DELAY_US, SC27XX_EFUSE_POLL_TIMEOUT); if (ret) { dev_err(efuse->dev, "timeout to update the efuse status\n"); return ret; } return 0; } static int sc27xx_efuse_read(void *context, u32 offset, void *val, size_t bytes) { struct sc27xx_efuse *efuse = context; u32 buf, blk_index = offset / SC27XX_EFUSE_BLOCK_WIDTH; u32 blk_offset = (offset % SC27XX_EFUSE_BLOCK_WIDTH) * BITS_PER_BYTE; int ret; if (blk_index > SC27XX_EFUSE_BLOCK_MAX || bytes > SC27XX_EFUSE_BLOCK_WIDTH) return -EINVAL; ret = sc27xx_efuse_lock(efuse); if (ret) return ret; /* Enable the efuse controller. */ ret = regmap_update_bits(efuse->regmap, efuse->var_data->module_en, SC27XX_EFUSE_EN, SC27XX_EFUSE_EN); if (ret) goto unlock_efuse; /* * Before reading, we should ensure the efuse controller is in * standby state. */ ret = sc27xx_efuse_poll_status(efuse, SC27XX_EFUSE_STANDBY); if (ret) goto disable_efuse; /* Set the block address to be read. */ ret = regmap_write(efuse->regmap, efuse->base + SC27XX_EFUSE_BLOCK_INDEX, blk_index & SC27XX_EFUSE_BLOCK_MASK); if (ret) goto disable_efuse; /* Start reading process from efuse memory. */ ret = regmap_update_bits(efuse->regmap, efuse->base + SC27XX_EFUSE_MODE_CTRL, SC27XX_EFUSE_RD_START, SC27XX_EFUSE_RD_START); if (ret) goto disable_efuse; /* * Polling the read done status to make sure the reading process * is completed, that means the data can be read out now. */ ret = sc27xx_efuse_poll_status(efuse, SC27XX_EFUSE_RD_DONE); if (ret) goto disable_efuse; /* Read data from efuse memory. */ ret = regmap_read(efuse->regmap, efuse->base + SC27XX_EFUSE_DATA_RD, &buf); if (ret) goto disable_efuse; /* Clear the read done flag. */ ret = regmap_update_bits(efuse->regmap, efuse->base + SC27XX_EFUSE_MODE_CTRL, SC27XX_EFUSE_CLR_RDDONE, SC27XX_EFUSE_CLR_RDDONE); disable_efuse: /* Disable the efuse controller after reading. */ regmap_update_bits(efuse->regmap, efuse->var_data->module_en, SC27XX_EFUSE_EN, 0); unlock_efuse: sc27xx_efuse_unlock(efuse); if (!ret) { buf >>= blk_offset; memcpy(val, &buf, bytes); } return ret; } static int sc27xx_efuse_probe(struct platform_device *pdev) { struct device_node *np = pdev->dev.of_node; struct nvmem_config econfig = { }; struct nvmem_device *nvmem; struct sc27xx_efuse *efuse; int ret; efuse = devm_kzalloc(&pdev->dev, sizeof(*efuse), GFP_KERNEL); if (!efuse) return -ENOMEM; efuse->regmap = dev_get_regmap(pdev->dev.parent, NULL); if (!efuse->regmap) { dev_err(&pdev->dev, "failed to get efuse regmap\n"); return -ENODEV; } ret = of_property_read_u32(np, "reg", &efuse->base); if (ret) { dev_err(&pdev->dev, "failed to get efuse base address\n"); return ret; } ret = of_hwspin_lock_get_id(np, 0); if (ret < 0) { dev_err(&pdev->dev, "failed to get hwspinlock id\n"); return ret; } efuse->hwlock = devm_hwspin_lock_request_specific(&pdev->dev, ret); if (!efuse->hwlock) { dev_err(&pdev->dev, "failed to request hwspinlock\n"); return -ENXIO; } mutex_init(&efuse->mutex); efuse->dev = &pdev->dev; efuse->var_data = of_device_get_match_data(&pdev->dev); econfig.stride = 1; econfig.word_size = 1; econfig.read_only = true; econfig.name = "sc27xx-efuse"; econfig.size = SC27XX_EFUSE_BLOCK_MAX * SC27XX_EFUSE_BLOCK_WIDTH; econfig.reg_read = sc27xx_efuse_read; econfig.priv = efuse; econfig.dev = &pdev->dev; econfig.add_legacy_fixed_of_cells = true; nvmem = devm_nvmem_register(&pdev->dev, &econfig); if (IS_ERR(nvmem)) { dev_err(&pdev->dev, "failed to register nvmem config\n"); return PTR_ERR(nvmem); } return 0; } static const struct of_device_id sc27xx_efuse_of_match[] = { { .compatible = "sprd,sc2731-efuse", .data = &sc2731_edata}, { .compatible = "sprd,sc2730-efuse", .data = &sc2730_edata}, { } }; static struct platform_driver sc27xx_efuse_driver = { .probe = sc27xx_efuse_probe, .driver = { .name = "sc27xx-efuse", .of_match_table = sc27xx_efuse_of_match, }, }; module_platform_driver(sc27xx_efuse_driver); MODULE_AUTHOR("Freeman Liu "); MODULE_DESCRIPTION("Spreadtrum SC27xx efuse driver"); MODULE_LICENSE("GPL v2");