// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) STMicroelectronics SA 2017
* Author: Fabien Dessenne <fabien.dessenne@st.com>
*/
#include <linux/bitrev.h>
#include <linux/clk.h>
#include <linux/crc32.h>
#include <linux/crc32poly.h>
#include <linux/io.h>
#include <linux/kernel.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_REV_IN_WORD (BIT(6) | BIT(5))
#define CRC_CR_REV_IN_BYTE BIT(5)
#define CRC_CR_REV_OUT BIT(7)
#define CRC32C_INIT_DEFAULT 0xFFFFFFFF
#define CRC_AUTOSUSPEND_DELAY 50
static unsigned int burst_size;
module_param(burst_size, uint, 0644);
MODULE_PARM_DESC(burst_size, "Select burst byte size (0 unlimited)");
struct stm32_crc {
struct list_head list;
struct device *dev;
void __iomem *regs;
struct clk *clk;
spinlock_t lock;
};
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 */
};
static int stm32_crc32_cra_init(struct crypto_tfm *tfm)
{
struct stm32_crc_ctx *mctx = crypto_tfm_ctx(tfm);
mctx->key = 0;
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 = CRC32C_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))
return -EINVAL;
mctx->key = get_unaligned_le32(key);
return 0;
}
static struct stm32_crc *stm32_crc_get_next_crc(void)
{
struct stm32_crc *crc;
spin_lock_bh(&crc_list.lock);
crc = list_first_entry(&crc_list.dev_list, struct stm32_crc, list);
if (crc)
list_move_tail(&crc->list, &crc_list.dev_list);
spin_unlock_bh(&crc_list.lock);
return crc;
}
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;
unsigned long flags;
crc = stm32_crc_get_next_crc();
if (!crc)
return -ENODEV;
pm_runtime_get_sync(crc->dev);
spin_lock_irqsave(&crc->lock, flags);
/* Reset, set key, poly and configure in bit reverse mode */
writel_relaxed(bitrev32(mctx->key), crc->regs + CRC_INIT);
writel_relaxed(bitrev32(mctx->poly), crc->regs + CRC_POL);
writel_relaxed(CRC_CR_RESET | CRC_CR_REV_IN_WORD | CRC_CR_REV_OUT,
crc->regs + CRC_CR);
/* Store partial result */
ctx->partial = readl_relaxed(crc->regs + CRC_DR);
spin_unlock_irqrestore(&crc->lock, flags);
pm_runtime_mark_last_busy(crc->dev);
pm_runtime_put_autosuspend(crc->dev);
return 0;
}
static int burst_update(struct shash_desc *desc, const u8 *d8,
size_t length)
{
struct stm32_crc_desc_ctx *ctx = shash_desc_ctx(desc);
struct stm32_crc_ctx *mctx = crypto_shash_ctx(desc->tfm);
struct stm32_crc *crc;
crc = stm32_crc_get_next_crc();
if (!crc)
return -ENODEV;
pm_runtime_get_sync(crc->dev);
if (!spin_trylock(&crc->lock)) {
/* Hardware is busy, calculate crc32 by software */
if (mctx->poly == CRC32_POLY_LE)
ctx->partial = crc32_le(ctx->partial, d8, length);
else
ctx->partial = __crc32c_le(ctx->partial, d8, length);
goto pm_out;
}
/*
* Restore previously calculated CRC for this context as init value
* Restore polynomial configuration
* Configure in register for word input data,
* Configure out register in reversed bit mode data.
*/
writel_relaxed(bitrev32(ctx->partial), crc->regs + CRC_INIT);
writel_relaxed(bitrev32(mctx->poly), crc->regs + CRC_POL);
writel_relaxed(CRC_CR_RESET | CRC_CR_REV_IN_WORD | CRC_CR_REV_OUT,
crc->regs + CRC_CR);
if (d8 != PTR_ALIGN(d8, sizeof(u32))) {
/* Configure for byte data */
writel_relaxed(CRC_CR_REV_IN_BYTE | CRC_CR_REV_OUT,
crc->regs + CRC_CR);
while (d8 != PTR_ALIGN(d8, sizeof(u32)) && length) {
writeb_relaxed(*d8++, crc->regs + CRC_DR);
length--;
}
/* Configure for word data */
writel_relaxed(CRC_CR_REV_IN_WORD | CRC_CR_REV_OUT,
crc->regs + CRC_CR);
}
for (; length >= sizeof(u32); d8 += sizeof(u32), length -= sizeof(u32))
writel_relaxed(*((u32 *)d8), crc->regs + CRC_DR);
if (length) {
/* Configure for byte data */
writel_relaxed(CRC_CR_REV_IN_BYTE | CRC_CR_REV_OUT,
crc->regs + CRC_CR);
while (length--)
writeb_relaxed(*d8++, crc->regs + CRC_DR);
}
/* Store partial result */
ctx->partial = readl_relaxed(crc->regs + CRC_DR);
spin_unlock(&crc->lock);
pm_out:
pm_runtime_mark_last_busy(crc->dev);
pm_runtime_put_autosuspend(crc->dev);
return 0;
}
static int stm32_crc_update(struct shash_desc *desc, const u8 *d8,
unsigned int length)
{
const unsigned int burst_sz = burst_size;
unsigned int rem_sz;
const u8 *cur;
size_t size;
int ret;
if (!burst_sz)
return burst_update(desc, d8, length);
/* Digest first bytes not 32bit aligned at first pass in the loop */
size = min_t(size_t, length, burst_sz + (size_t)d8 -
ALIGN_DOWN((size_t)d8, sizeof(u32)));
for (rem_sz = length, cur = d8; rem_sz;
rem_sz -= size, cur += size, size = min(rem_sz, burst_sz)) {
ret = burst_update(desc, cur, size);
if (ret)
return ret;
}
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 unsigned int refcnt;
static DEFINE_MUTEX(refcnt_lock);
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 = "stm32-crc32-crc32",
.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 = "stm32-crc32-crc32c",
.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;
int ret;
crc = devm_kzalloc(dev, sizeof(*crc), GFP_KERNEL);
if (!crc)
return -ENOMEM;
crc->dev = dev;
crc->regs = devm_platform_ioremap_resource(pdev, 0);
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_irq_safe(dev);
pm_runtime_enable(dev);
spin_lock_init(&crc->lock);
platform_set_drvdata(pdev, crc);
spin_lock(&crc_list.lock);
list_add(&crc->list, &crc_list.dev_list);
spin_unlock(&crc_list.lock);
mutex_lock(&refcnt_lock);
if (!refcnt) {
ret = crypto_register_shashes(algs, ARRAY_SIZE(algs));
if (ret) {
mutex_unlock(&refcnt_lock);
dev_err(dev, "Failed to register\n");
clk_disable_unprepare(crc->clk);
return ret;
}
}
refcnt++;
mutex_unlock(&refcnt_lock);
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) {
pm_runtime_put_noidle(crc->dev);
return ret;
}
spin_lock(&crc_list.lock);
list_del(&crc->list);
spin_unlock(&crc_list.lock);
mutex_lock(&refcnt_lock);
if (!--refcnt)
crypto_unregister_shashes(algs, ARRAY_SIZE(algs));
mutex_unlock(&refcnt_lock);
pm_runtime_disable(crc->dev);
pm_runtime_put_noidle(crc->dev);
clk_disable_unprepare(crc->clk);
return 0;
}
static int __maybe_unused stm32_crc_suspend(struct device *dev)
{
struct stm32_crc *crc = dev_get_drvdata(dev);
int ret;
ret = pm_runtime_force_suspend(dev);
if (ret)
return ret;
clk_unprepare(crc->clk);
return 0;
}
static int __maybe_unused stm32_crc_resume(struct device *dev)
{
struct stm32_crc *crc = dev_get_drvdata(dev);
int ret;
ret = clk_prepare(crc->clk);
if (ret) {
dev_err(crc->dev, "Failed to prepare clock\n");
return ret;
}
return pm_runtime_force_resume(dev);
}
static int __maybe_unused stm32_crc_runtime_suspend(struct device *dev)
{
struct stm32_crc *crc = dev_get_drvdata(dev);
clk_disable(crc->clk);
return 0;
}
static int __maybe_unused stm32_crc_runtime_resume(struct device *dev)
{
struct stm32_crc *crc = dev_get_drvdata(dev);
int ret;
ret = clk_enable(crc->clk);
if (ret) {
dev_err(crc->dev, "Failed to enable clock\n");
return ret;
}
return 0;
}
static const struct dev_pm_ops stm32_crc_pm_ops = {
SET_SYSTEM_SLEEP_PM_OPS(stm32_crc_suspend,
stm32_crc_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");