--- /dev/null
+/*
+ * 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/module.h>
+#include <linux/platform_device.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
+
+/* Polynomial reversed */
+#define POLY_CRC32 0xEDB88320
+#define POLY_CRC32C 0x82F63B78
+
+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 = POLY_CRC32;
+ 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 = POLY_CRC32C;
+ 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);
+
+ /* Reset, set key, poly and configure in bit reverse mode */
+ writel(bitrev32(mctx->key), ctx->crc->regs + CRC_INIT);
+ writel(bitrev32(mctx->poly), ctx->crc->regs + CRC_POL);
+ writel(CRC_CR_RESET | CRC_CR_REVERSE, ctx->crc->regs + CRC_CR);
+
+ /* Store partial result */
+ ctx->partial = readl(ctx->crc->regs + CRC_DR);
+ ctx->crc->nb_pending_bytes = 0;
+
+ 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;
+
+ 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(*(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(*(d32++), crc->regs + CRC_DR);
+
+ /* Store partial result */
+ ctx->partial = readl(crc->regs + CRC_DR);
+
+ /* 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 == POLY_CRC32C ?
+ ~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_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_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;
+ }
+
+ 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");
+
+ return 0;
+}
+
+static int stm32_crc_remove(struct platform_device *pdev)
+{
+ struct stm32_crc *crc = platform_get_drvdata(pdev);
+
+ spin_lock(&crc_list.lock);
+ list_del(&crc->list);
+ spin_unlock(&crc_list.lock);
+
+ crypto_unregister_shash(algs);
+
+ clk_disable_unprepare(crc->clk);
+
+ return 0;
+}
+
+static const struct of_device_id stm32_dt_ids[] = {
+ { .compatible = "st,stm32f7-crc", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, sti_dt_ids);
+
+static struct platform_driver stm32_crc_driver = {
+ .probe = stm32_crc_probe,
+ .remove = stm32_crc_remove,
+ .driver = {
+ .name = DRIVER_NAME,
+ .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");
projects / GitHub / moto-9609 / android_kernel_motorola_exynos9610.git / commitdiff