diff options
Diffstat (limited to 'drivers/crypto/stm32/stm32-crc32.c')
-rw-r--r-- | drivers/crypto/stm32/stm32-crc32.c | 387 |
1 files changed, 387 insertions, 0 deletions
diff --git a/drivers/crypto/stm32/stm32-crc32.c b/drivers/crypto/stm32/stm32-crc32.c new file mode 100644 index 000000000000..29d2095d9dfd --- /dev/null +++ b/drivers/crypto/stm32/stm32-crc32.c @@ -0,0 +1,387 @@ +/* + * Copyright (C) STMicroelectronics SA 2017 + * Author: Fabien Dessenne <fabien.dessenne@st.com> + * License terms: GNU General Public License (GPL), version 2 + */ + +#include <linux/bitrev.h> +#include <linux/clk.h> +#include <linux/crc32poly.h> +#include <linux/module.h> +#include <linux/mod_devicetable.h> +#include <linux/platform_device.h> +#include <linux/pm_runtime.h> + +#include <crypto/internal/hash.h> + +#include <asm/unaligned.h> + +#define DRIVER_NAME "stm32-crc32" +#define CHKSUM_DIGEST_SIZE 4 +#define CHKSUM_BLOCK_SIZE 1 + +/* Registers */ +#define CRC_DR 0x00000000 +#define CRC_CR 0x00000008 +#define CRC_INIT 0x00000010 +#define CRC_POL 0x00000014 + +/* Registers values */ +#define CRC_CR_RESET BIT(0) +#define CRC_CR_REVERSE (BIT(7) | BIT(6) | BIT(5)) +#define CRC_INIT_DEFAULT 0xFFFFFFFF + +#define CRC_AUTOSUSPEND_DELAY 50 + +struct stm32_crc { + struct list_head list; + struct device *dev; + void __iomem *regs; + struct clk *clk; + u8 pending_data[sizeof(u32)]; + size_t nb_pending_bytes; +}; + +struct stm32_crc_list { + struct list_head dev_list; + spinlock_t lock; /* protect dev_list */ +}; + +static struct stm32_crc_list crc_list = { + .dev_list = LIST_HEAD_INIT(crc_list.dev_list), + .lock = __SPIN_LOCK_UNLOCKED(crc_list.lock), +}; + +struct stm32_crc_ctx { + u32 key; + u32 poly; +}; + +struct stm32_crc_desc_ctx { + u32 partial; /* crc32c: partial in first 4 bytes of that struct */ + struct stm32_crc *crc; +}; + +static int stm32_crc32_cra_init(struct crypto_tfm *tfm) +{ + struct stm32_crc_ctx *mctx = crypto_tfm_ctx(tfm); + + mctx->key = CRC_INIT_DEFAULT; + mctx->poly = CRC32_POLY_LE; + return 0; +} + +static int stm32_crc32c_cra_init(struct crypto_tfm *tfm) +{ + struct stm32_crc_ctx *mctx = crypto_tfm_ctx(tfm); + + mctx->key = CRC_INIT_DEFAULT; + mctx->poly = CRC32C_POLY_LE; + return 0; +} + +static int stm32_crc_setkey(struct crypto_shash *tfm, const u8 *key, + unsigned int keylen) +{ + struct stm32_crc_ctx *mctx = crypto_shash_ctx(tfm); + + if (keylen != sizeof(u32)) { + crypto_shash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN); + return -EINVAL; + } + + mctx->key = get_unaligned_le32(key); + return 0; +} + +static int stm32_crc_init(struct shash_desc *desc) +{ + struct stm32_crc_desc_ctx *ctx = shash_desc_ctx(desc); + struct stm32_crc_ctx *mctx = crypto_shash_ctx(desc->tfm); + struct stm32_crc *crc; + + spin_lock_bh(&crc_list.lock); + list_for_each_entry(crc, &crc_list.dev_list, list) { + ctx->crc = crc; + break; + } + spin_unlock_bh(&crc_list.lock); + + pm_runtime_get_sync(ctx->crc->dev); + + /* Reset, set key, poly and configure in bit reverse mode */ + writel_relaxed(bitrev32(mctx->key), ctx->crc->regs + CRC_INIT); + writel_relaxed(bitrev32(mctx->poly), ctx->crc->regs + CRC_POL); + writel_relaxed(CRC_CR_RESET | CRC_CR_REVERSE, ctx->crc->regs + CRC_CR); + + /* Store partial result */ + ctx->partial = readl_relaxed(ctx->crc->regs + CRC_DR); + ctx->crc->nb_pending_bytes = 0; + + pm_runtime_mark_last_busy(ctx->crc->dev); + pm_runtime_put_autosuspend(ctx->crc->dev); + + return 0; +} + +static int stm32_crc_update(struct shash_desc *desc, const u8 *d8, + unsigned int length) +{ + struct stm32_crc_desc_ctx *ctx = shash_desc_ctx(desc); + struct stm32_crc *crc = ctx->crc; + u32 *d32; + unsigned int i; + + pm_runtime_get_sync(crc->dev); + + if (unlikely(crc->nb_pending_bytes)) { + while (crc->nb_pending_bytes != sizeof(u32) && length) { + /* Fill in pending data */ + crc->pending_data[crc->nb_pending_bytes++] = *(d8++); + length--; + } + + if (crc->nb_pending_bytes == sizeof(u32)) { + /* Process completed pending data */ + writel_relaxed(*(u32 *)crc->pending_data, + crc->regs + CRC_DR); + crc->nb_pending_bytes = 0; + } + } + + d32 = (u32 *)d8; + for (i = 0; i < length >> 2; i++) + /* Process 32 bits data */ + writel_relaxed(*(d32++), crc->regs + CRC_DR); + + /* Store partial result */ + ctx->partial = readl_relaxed(crc->regs + CRC_DR); + + pm_runtime_mark_last_busy(crc->dev); + pm_runtime_put_autosuspend(crc->dev); + + /* Check for pending data (non 32 bits) */ + length &= 3; + if (likely(!length)) + return 0; + + if ((crc->nb_pending_bytes + length) >= sizeof(u32)) { + /* Shall not happen */ + dev_err(crc->dev, "Pending data overflow\n"); + return -EINVAL; + } + + d8 = (const u8 *)d32; + for (i = 0; i < length; i++) + /* Store pending data */ + crc->pending_data[crc->nb_pending_bytes++] = *(d8++); + + return 0; +} + +static int stm32_crc_final(struct shash_desc *desc, u8 *out) +{ + struct stm32_crc_desc_ctx *ctx = shash_desc_ctx(desc); + struct stm32_crc_ctx *mctx = crypto_shash_ctx(desc->tfm); + + /* Send computed CRC */ + put_unaligned_le32(mctx->poly == CRC32C_POLY_LE ? + ~ctx->partial : ctx->partial, out); + + return 0; +} + +static int stm32_crc_finup(struct shash_desc *desc, const u8 *data, + unsigned int length, u8 *out) +{ + return stm32_crc_update(desc, data, length) ?: + stm32_crc_final(desc, out); +} + +static int stm32_crc_digest(struct shash_desc *desc, const u8 *data, + unsigned int length, u8 *out) +{ + return stm32_crc_init(desc) ?: stm32_crc_finup(desc, data, length, out); +} + +static struct shash_alg algs[] = { + /* CRC-32 */ + { + .setkey = stm32_crc_setkey, + .init = stm32_crc_init, + .update = stm32_crc_update, + .final = stm32_crc_final, + .finup = stm32_crc_finup, + .digest = stm32_crc_digest, + .descsize = sizeof(struct stm32_crc_desc_ctx), + .digestsize = CHKSUM_DIGEST_SIZE, + .base = { + .cra_name = "crc32", + .cra_driver_name = DRIVER_NAME, + .cra_priority = 200, + .cra_flags = CRYPTO_ALG_OPTIONAL_KEY, + .cra_blocksize = CHKSUM_BLOCK_SIZE, + .cra_alignmask = 3, + .cra_ctxsize = sizeof(struct stm32_crc_ctx), + .cra_module = THIS_MODULE, + .cra_init = stm32_crc32_cra_init, + } + }, + /* CRC-32Castagnoli */ + { + .setkey = stm32_crc_setkey, + .init = stm32_crc_init, + .update = stm32_crc_update, + .final = stm32_crc_final, + .finup = stm32_crc_finup, + .digest = stm32_crc_digest, + .descsize = sizeof(struct stm32_crc_desc_ctx), + .digestsize = CHKSUM_DIGEST_SIZE, + .base = { + .cra_name = "crc32c", + .cra_driver_name = DRIVER_NAME, + .cra_priority = 200, + .cra_flags = CRYPTO_ALG_OPTIONAL_KEY, + .cra_blocksize = CHKSUM_BLOCK_SIZE, + .cra_alignmask = 3, + .cra_ctxsize = sizeof(struct stm32_crc_ctx), + .cra_module = THIS_MODULE, + .cra_init = stm32_crc32c_cra_init, + } + } +}; + +static int stm32_crc_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct stm32_crc *crc; + struct resource *res; + int ret; + + crc = devm_kzalloc(dev, sizeof(*crc), GFP_KERNEL); + if (!crc) + return -ENOMEM; + + crc->dev = dev; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + crc->regs = devm_ioremap_resource(dev, res); + if (IS_ERR(crc->regs)) { + dev_err(dev, "Cannot map CRC IO\n"); + return PTR_ERR(crc->regs); + } + + crc->clk = devm_clk_get(dev, NULL); + if (IS_ERR(crc->clk)) { + dev_err(dev, "Could not get clock\n"); + return PTR_ERR(crc->clk); + } + + ret = clk_prepare_enable(crc->clk); + if (ret) { + dev_err(crc->dev, "Failed to enable clock\n"); + return ret; + } + + pm_runtime_set_autosuspend_delay(dev, CRC_AUTOSUSPEND_DELAY); + pm_runtime_use_autosuspend(dev); + + pm_runtime_get_noresume(dev); + pm_runtime_set_active(dev); + pm_runtime_enable(dev); + + platform_set_drvdata(pdev, crc); + + spin_lock(&crc_list.lock); + list_add(&crc->list, &crc_list.dev_list); + spin_unlock(&crc_list.lock); + + ret = crypto_register_shashes(algs, ARRAY_SIZE(algs)); + if (ret) { + dev_err(dev, "Failed to register\n"); + clk_disable_unprepare(crc->clk); + return ret; + } + + dev_info(dev, "Initialized\n"); + + pm_runtime_put_sync(dev); + + return 0; +} + +static int stm32_crc_remove(struct platform_device *pdev) +{ + struct stm32_crc *crc = platform_get_drvdata(pdev); + int ret = pm_runtime_get_sync(crc->dev); + + if (ret < 0) + return ret; + + spin_lock(&crc_list.lock); + list_del(&crc->list); + spin_unlock(&crc_list.lock); + + crypto_unregister_shashes(algs, ARRAY_SIZE(algs)); + + pm_runtime_disable(crc->dev); + pm_runtime_put_noidle(crc->dev); + + clk_disable_unprepare(crc->clk); + + return 0; +} + +#ifdef CONFIG_PM +static int stm32_crc_runtime_suspend(struct device *dev) +{ + struct stm32_crc *crc = dev_get_drvdata(dev); + + clk_disable_unprepare(crc->clk); + + return 0; +} + +static int stm32_crc_runtime_resume(struct device *dev) +{ + struct stm32_crc *crc = dev_get_drvdata(dev); + int ret; + + ret = clk_prepare_enable(crc->clk); + if (ret) { + dev_err(crc->dev, "Failed to prepare_enable clock\n"); + return ret; + } + + return 0; +} +#endif + +static const struct dev_pm_ops stm32_crc_pm_ops = { + SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, + pm_runtime_force_resume) + SET_RUNTIME_PM_OPS(stm32_crc_runtime_suspend, + stm32_crc_runtime_resume, NULL) +}; + +static const struct of_device_id stm32_dt_ids[] = { + { .compatible = "st,stm32f7-crc", }, + {}, +}; +MODULE_DEVICE_TABLE(of, stm32_dt_ids); + +static struct platform_driver stm32_crc_driver = { + .probe = stm32_crc_probe, + .remove = stm32_crc_remove, + .driver = { + .name = DRIVER_NAME, + .pm = &stm32_crc_pm_ops, + .of_match_table = stm32_dt_ids, + }, +}; + +module_platform_driver(stm32_crc_driver); + +MODULE_AUTHOR("Fabien Dessenne <fabien.dessenne@st.com>"); +MODULE_DESCRIPTION("STMicrolectronics STM32 CRC32 hardware driver"); +MODULE_LICENSE("GPL"); |