diff options
Diffstat (limited to 'drivers/nvmem/sprd-efuse.c')
| -rw-r--r-- | drivers/nvmem/sprd-efuse.c | 424 |
1 files changed, 424 insertions, 0 deletions
diff --git a/drivers/nvmem/sprd-efuse.c b/drivers/nvmem/sprd-efuse.c new file mode 100644 index 000000000000..2f1e0fbd1901 --- /dev/null +++ b/drivers/nvmem/sprd-efuse.c @@ -0,0 +1,424 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (C) 2019 Spreadtrum Communications Inc. + +#include <linux/clk.h> +#include <linux/delay.h> +#include <linux/hwspinlock.h> +#include <linux/io.h> +#include <linux/module.h> +#include <linux/nvmem-provider.h> +#include <linux/of_device.h> +#include <linux/platform_device.h> + +#define SPRD_EFUSE_ENABLE 0x20 +#define SPRD_EFUSE_ERR_FLAG 0x24 +#define SPRD_EFUSE_ERR_CLR 0x28 +#define SPRD_EFUSE_MAGIC_NUM 0x2c +#define SPRD_EFUSE_FW_CFG 0x50 +#define SPRD_EFUSE_PW_SWT 0x54 +#define SPRD_EFUSE_MEM(val) (0x1000 + ((val) << 2)) + +#define SPRD_EFUSE_VDD_EN BIT(0) +#define SPRD_EFUSE_AUTO_CHECK_EN BIT(1) +#define SPRD_EFUSE_DOUBLE_EN BIT(2) +#define SPRD_EFUSE_MARGIN_RD_EN BIT(3) +#define SPRD_EFUSE_LOCK_WR_EN BIT(4) + +#define SPRD_EFUSE_ERR_CLR_MASK GENMASK(13, 0) + +#define SPRD_EFUSE_ENK1_ON BIT(0) +#define SPRD_EFUSE_ENK2_ON BIT(1) +#define SPRD_EFUSE_PROG_EN BIT(2) + +#define SPRD_EFUSE_MAGIC_NUMBER 0x8810 + +/* Block width (bytes) definitions */ +#define SPRD_EFUSE_BLOCK_WIDTH 4 + +/* + * The Spreadtrum AP efuse contains 2 parts: normal efuse and secure efuse, + * and we can only access the normal efuse in kernel. So define the normal + * block offset index and normal block numbers. + */ +#define SPRD_EFUSE_NORMAL_BLOCK_NUMS 24 +#define SPRD_EFUSE_NORMAL_BLOCK_OFFSET 72 + +/* Timeout (ms) for the trylock of hardware spinlocks */ +#define SPRD_EFUSE_HWLOCK_TIMEOUT 5000 + +/* + * Since different Spreadtrum SoC chip can have different normal block numbers + * and offset. And some SoC can support block double feature, which means + * when reading or writing data to efuse memory, the controller can save double + * data in case one data become incorrect after a long period. + * + * Thus we should save them in the device data structure. + */ +struct sprd_efuse_variant_data { + u32 blk_nums; + u32 blk_offset; + bool blk_double; +}; + +struct sprd_efuse { + struct device *dev; + struct clk *clk; + struct hwspinlock *hwlock; + struct mutex mutex; + void __iomem *base; + const struct sprd_efuse_variant_data *data; +}; + +static const struct sprd_efuse_variant_data ums312_data = { + .blk_nums = SPRD_EFUSE_NORMAL_BLOCK_NUMS, + .blk_offset = SPRD_EFUSE_NORMAL_BLOCK_OFFSET, + .blk_double = false, +}; + +/* + * 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 sprd_efuse_lock(struct sprd_efuse *efuse) +{ + int ret; + + mutex_lock(&efuse->mutex); + + ret = hwspin_lock_timeout_raw(efuse->hwlock, + SPRD_EFUSE_HWLOCK_TIMEOUT); + if (ret) { + dev_err(efuse->dev, "timeout get the hwspinlock\n"); + mutex_unlock(&efuse->mutex); + return ret; + } + + return 0; +} + +static void sprd_efuse_unlock(struct sprd_efuse *efuse) +{ + hwspin_unlock_raw(efuse->hwlock); + mutex_unlock(&efuse->mutex); +} + +static void sprd_efuse_set_prog_power(struct sprd_efuse *efuse, bool en) +{ + u32 val = readl(efuse->base + SPRD_EFUSE_PW_SWT); + + if (en) + val &= ~SPRD_EFUSE_ENK2_ON; + else + val &= ~SPRD_EFUSE_ENK1_ON; + + writel(val, efuse->base + SPRD_EFUSE_PW_SWT); + + /* Open or close efuse power need wait 1000us to make power stable. */ + usleep_range(1000, 1200); + + if (en) + val |= SPRD_EFUSE_ENK1_ON; + else + val |= SPRD_EFUSE_ENK2_ON; + + writel(val, efuse->base + SPRD_EFUSE_PW_SWT); + + /* Open or close efuse power need wait 1000us to make power stable. */ + usleep_range(1000, 1200); +} + +static void sprd_efuse_set_read_power(struct sprd_efuse *efuse, bool en) +{ + u32 val = readl(efuse->base + SPRD_EFUSE_ENABLE); + + if (en) + val |= SPRD_EFUSE_VDD_EN; + else + val &= ~SPRD_EFUSE_VDD_EN; + + writel(val, efuse->base + SPRD_EFUSE_ENABLE); + + /* Open or close efuse power need wait 1000us to make power stable. */ + usleep_range(1000, 1200); +} + +static void sprd_efuse_set_prog_lock(struct sprd_efuse *efuse, bool en) +{ + u32 val = readl(efuse->base + SPRD_EFUSE_ENABLE); + + if (en) + val |= SPRD_EFUSE_LOCK_WR_EN; + else + val &= ~SPRD_EFUSE_LOCK_WR_EN; + + writel(val, efuse->base + SPRD_EFUSE_ENABLE); +} + +static void sprd_efuse_set_auto_check(struct sprd_efuse *efuse, bool en) +{ + u32 val = readl(efuse->base + SPRD_EFUSE_ENABLE); + + if (en) + val |= SPRD_EFUSE_AUTO_CHECK_EN; + else + val &= ~SPRD_EFUSE_AUTO_CHECK_EN; + + writel(val, efuse->base + SPRD_EFUSE_ENABLE); +} + +static void sprd_efuse_set_data_double(struct sprd_efuse *efuse, bool en) +{ + u32 val = readl(efuse->base + SPRD_EFUSE_ENABLE); + + if (en) + val |= SPRD_EFUSE_DOUBLE_EN; + else + val &= ~SPRD_EFUSE_DOUBLE_EN; + + writel(val, efuse->base + SPRD_EFUSE_ENABLE); +} + +static void sprd_efuse_set_prog_en(struct sprd_efuse *efuse, bool en) +{ + u32 val = readl(efuse->base + SPRD_EFUSE_PW_SWT); + + if (en) + val |= SPRD_EFUSE_PROG_EN; + else + val &= ~SPRD_EFUSE_PROG_EN; + + writel(val, efuse->base + SPRD_EFUSE_PW_SWT); +} + +static int sprd_efuse_raw_prog(struct sprd_efuse *efuse, u32 blk, bool doub, + bool lock, u32 *data) +{ + u32 status; + int ret = 0; + + /* + * We need set the correct magic number before writing the efuse to + * allow programming, and block other programming until we clear the + * magic number. + */ + writel(SPRD_EFUSE_MAGIC_NUMBER, + efuse->base + SPRD_EFUSE_MAGIC_NUM); + + /* + * Power on the efuse, enable programme and enable double data + * if asked. + */ + sprd_efuse_set_prog_power(efuse, true); + sprd_efuse_set_prog_en(efuse, true); + sprd_efuse_set_data_double(efuse, doub); + + /* + * Enable the auto-check function to validate if the programming is + * successful. + */ + sprd_efuse_set_auto_check(efuse, true); + + writel(*data, efuse->base + SPRD_EFUSE_MEM(blk)); + + /* Disable auto-check and data double after programming */ + sprd_efuse_set_auto_check(efuse, false); + sprd_efuse_set_data_double(efuse, false); + + /* + * Check the efuse error status, if the programming is successful, + * we should lock this efuse block to avoid programming again. + */ + status = readl(efuse->base + SPRD_EFUSE_ERR_FLAG); + if (status) { + dev_err(efuse->dev, + "write error status %d of block %d\n", ret, blk); + + writel(SPRD_EFUSE_ERR_CLR_MASK, + efuse->base + SPRD_EFUSE_ERR_CLR); + ret = -EBUSY; + } else { + sprd_efuse_set_prog_lock(efuse, lock); + writel(*data, efuse->base + SPRD_EFUSE_MEM(blk)); + sprd_efuse_set_prog_lock(efuse, false); + } + + sprd_efuse_set_prog_power(efuse, false); + writel(0, efuse->base + SPRD_EFUSE_MAGIC_NUM); + + return ret; +} + +static int sprd_efuse_raw_read(struct sprd_efuse *efuse, int blk, u32 *val, + bool doub) +{ + u32 status; + + /* + * Need power on the efuse before reading data from efuse, and will + * power off the efuse after reading process. + */ + sprd_efuse_set_read_power(efuse, true); + + /* Enable double data if asked */ + sprd_efuse_set_data_double(efuse, doub); + + /* Start to read data from efuse block */ + *val = readl(efuse->base + SPRD_EFUSE_MEM(blk)); + + /* Disable double data */ + sprd_efuse_set_data_double(efuse, false); + + /* Power off the efuse */ + sprd_efuse_set_read_power(efuse, false); + + /* + * Check the efuse error status and clear them if there are some + * errors occurred. + */ + status = readl(efuse->base + SPRD_EFUSE_ERR_FLAG); + if (status) { + dev_err(efuse->dev, + "read error status %d of block %d\n", status, blk); + + writel(SPRD_EFUSE_ERR_CLR_MASK, + efuse->base + SPRD_EFUSE_ERR_CLR); + return -EBUSY; + } + + return 0; +} + +static int sprd_efuse_read(void *context, u32 offset, void *val, size_t bytes) +{ + struct sprd_efuse *efuse = context; + bool blk_double = efuse->data->blk_double; + u32 index = offset / SPRD_EFUSE_BLOCK_WIDTH + efuse->data->blk_offset; + u32 blk_offset = (offset % SPRD_EFUSE_BLOCK_WIDTH) * BITS_PER_BYTE; + u32 data; + int ret; + + ret = sprd_efuse_lock(efuse); + if (ret) + return ret; + + ret = clk_prepare_enable(efuse->clk); + if (ret) + goto unlock; + + ret = sprd_efuse_raw_read(efuse, index, &data, blk_double); + if (!ret) { + data >>= blk_offset; + memcpy(val, &data, bytes); + } + + clk_disable_unprepare(efuse->clk); + +unlock: + sprd_efuse_unlock(efuse); + return ret; +} + +static int sprd_efuse_write(void *context, u32 offset, void *val, size_t bytes) +{ + struct sprd_efuse *efuse = context; + int ret; + + ret = sprd_efuse_lock(efuse); + if (ret) + return ret; + + ret = clk_prepare_enable(efuse->clk); + if (ret) + goto unlock; + + ret = sprd_efuse_raw_prog(efuse, offset, false, false, val); + + clk_disable_unprepare(efuse->clk); + +unlock: + sprd_efuse_unlock(efuse); + return ret; +} + +static int sprd_efuse_probe(struct platform_device *pdev) +{ + struct device_node *np = pdev->dev.of_node; + struct nvmem_device *nvmem; + struct nvmem_config econfig = { }; + struct sprd_efuse *efuse; + const struct sprd_efuse_variant_data *pdata; + int ret; + + pdata = of_device_get_match_data(&pdev->dev); + if (!pdata) { + dev_err(&pdev->dev, "No matching driver data found\n"); + return -EINVAL; + } + + efuse = devm_kzalloc(&pdev->dev, sizeof(*efuse), GFP_KERNEL); + if (!efuse) + return -ENOMEM; + + efuse->base = devm_platform_ioremap_resource(pdev, 0); + if (!efuse->base) + return -ENOMEM; + + ret = of_hwspin_lock_get_id(np, 0); + if (ret < 0) { + dev_err(&pdev->dev, "failed to get hwlock id\n"); + return ret; + } + + efuse->hwlock = devm_hwspin_lock_request_specific(&pdev->dev, ret); + if (!efuse->hwlock) { + dev_err(&pdev->dev, "failed to request hwlock\n"); + return -ENXIO; + } + + efuse->clk = devm_clk_get(&pdev->dev, "enable"); + if (IS_ERR(efuse->clk)) { + dev_err(&pdev->dev, "failed to get enable clock\n"); + return PTR_ERR(efuse->clk); + } + + mutex_init(&efuse->mutex); + efuse->dev = &pdev->dev; + efuse->data = pdata; + + econfig.stride = 1; + econfig.word_size = 1; + econfig.read_only = false; + econfig.name = "sprd-efuse"; + econfig.size = efuse->data->blk_nums * SPRD_EFUSE_BLOCK_WIDTH; + econfig.reg_read = sprd_efuse_read; + econfig.reg_write = sprd_efuse_write; + econfig.priv = efuse; + econfig.dev = &pdev->dev; + nvmem = devm_nvmem_register(&pdev->dev, &econfig); + if (IS_ERR(nvmem)) { + dev_err(&pdev->dev, "failed to register nvmem\n"); + return PTR_ERR(nvmem); + } + + return 0; +} + +static const struct of_device_id sprd_efuse_of_match[] = { + { .compatible = "sprd,ums312-efuse", .data = &ums312_data }, + { } +}; + +static struct platform_driver sprd_efuse_driver = { + .probe = sprd_efuse_probe, + .driver = { + .name = "sprd-efuse", + .of_match_table = sprd_efuse_of_match, + }, +}; + +module_platform_driver(sprd_efuse_driver); + +MODULE_AUTHOR("Freeman Liu <freeman.liu@spreadtrum.com>"); +MODULE_DESCRIPTION("Spreadtrum AP efuse driver"); +MODULE_LICENSE("GPL v2"); |