crypto: stm32_hash: Add HASH driver

The driver manages the HASH processor IP on STM32MP1
Signed-off-by: Lionel Debieve <lionel.debieve@st.com>
Change-Id: I3b67c80c16d819f86b951dae29a6c465e51ad585

drivers/st/crypto/stm32_hash.c

+/*
+ * Copyright (c) 2019, STMicroelectronics - All Rights Reserved
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <assert.h>
+#include <errno.h>
+#include <stdint.h>
+
+#include <libfdt.h>
+
+#include <platform_def.h>
+
+#include <arch_helpers.h>
+#include <common/debug.h>
+#include <drivers/delay_timer.h>
+#include <drivers/st/stm32_hash.h>
+#include <drivers/st/stm32mp_reset.h>
+#include <lib/mmio.h>
+#include <lib/utils.h>
+#include <plat/common/platform.h>
+
+#define DT_HASH_COMPAT			"st,stm32f756-hash"
+
+#define HASH_CR				0x00U
+#define HASH_DIN			0x04U
+#define HASH_STR			0x08U
+#define HASH_SR				0x24U
+#define HASH_HREG(x)			(0x310U + ((x) * 0x04U))
+
+/* Control Register */
+#define HASH_CR_INIT			BIT(2)
+#define HASH_CR_DATATYPE_SHIFT		U(4)
+
+#define HASH_CR_ALGO_SHA1		0x0U
+#define HASH_CR_ALGO_MD5		BIT(7)
+#define HASH_CR_ALGO_SHA224		BIT(18)
+#define HASH_CR_ALGO_SHA256		(BIT(18) | BIT(7))
+
+/* Status Flags */
+#define HASH_SR_DCIS			BIT(1)
+#define HASH_SR_BUSY			BIT(3)
+
+/* STR Register */
+#define HASH_STR_NBLW_MASK		GENMASK(4, 0)
+#define HASH_STR_DCAL			BIT(8)
+
+#define MD5_DIGEST_SIZE			16U
+#define SHA1_DIGEST_SIZE		20U
+#define SHA224_DIGEST_SIZE		28U
+#define SHA256_DIGEST_SIZE		32U
+
+#define HASH_TIMEOUT_US			10000U
+
+enum stm32_hash_data_format {
+	HASH_DATA_32_BITS,
+	HASH_DATA_16_BITS,
+	HASH_DATA_8_BITS,
+	HASH_DATA_1_BIT
+};
+
+struct stm32_hash_instance {
+	uintptr_t base;
+	unsigned int clock;
+	size_t digest_size;
+};
+
+struct stm32_hash_remain {
+	uint32_t buffer;
+	size_t length;
+};
+
+/* Expect a single HASH peripheral */
+static struct stm32_hash_instance stm32_hash;
+static struct stm32_hash_remain stm32_remain;
+
+static uintptr_t hash_base(void)
+{
+	return stm32_hash.base;
+}
+
+static int hash_wait_busy(void)
+{
+	uint64_t timeout = timeout_init_us(HASH_TIMEOUT_US);
+
+	while ((mmio_read_32(hash_base() + HASH_SR) & HASH_SR_BUSY) != 0U) {
+		if (timeout_elapsed(timeout)) {
+			ERROR("%s: busy timeout\n", __func__);
+			return -ETIMEDOUT;
+		}
+	}
+
+	return 0;
+}
+
+static int hash_wait_computation(void)
+{
+	uint64_t timeout = timeout_init_us(HASH_TIMEOUT_US);
+
+	while ((mmio_read_32(hash_base() + HASH_SR) & HASH_SR_DCIS) == 0U) {
+		if (timeout_elapsed(timeout)) {
+			ERROR("%s: busy timeout\n", __func__);
+			return -ETIMEDOUT;
+		}
+	}
+
+	return 0;
+}
+
+static int hash_write_data(uint32_t data)
+{
+	int ret;
+
+	ret = hash_wait_busy();
+	if (ret != 0) {
+		return ret;
+	}
+
+	mmio_write_32(hash_base() + HASH_DIN, data);
+
+	return 0;
+}
+
+static void hash_hw_init(enum stm32_hash_algo_mode mode)
+{
+	uint32_t reg;
+
+	reg = HASH_CR_INIT | (HASH_DATA_8_BITS << HASH_CR_DATATYPE_SHIFT);
+
+	switch (mode) {
+	case HASH_MD5SUM:
+		reg |= HASH_CR_ALGO_MD5;
+		stm32_hash.digest_size = MD5_DIGEST_SIZE;
+		break;
+	case HASH_SHA1:
+		reg |= HASH_CR_ALGO_SHA1;
+		stm32_hash.digest_size = SHA1_DIGEST_SIZE;
+		break;
+	case HASH_SHA224:
+		reg |= HASH_CR_ALGO_SHA224;
+		stm32_hash.digest_size = SHA224_DIGEST_SIZE;
+		break;
+	/* Default selected algo is SHA256 */
+	case HASH_SHA256:
+	default:
+		reg |= HASH_CR_ALGO_SHA256;
+		stm32_hash.digest_size = SHA256_DIGEST_SIZE;
+		break;
+	}
+
+	mmio_write_32(hash_base() + HASH_CR, reg);
+}
+
+static int hash_get_digest(uint8_t *digest)
+{
+	int ret;
+	uint32_t i;
+	uint32_t dsg;
+
+	ret = hash_wait_computation();
+	if (ret != 0) {
+		return ret;
+	}
+
+	for (i = 0U; i < (stm32_hash.digest_size / sizeof(uint32_t)); i++) {
+		dsg = __builtin_bswap32(mmio_read_32(hash_base() +
+						     HASH_HREG(i)));
+		memcpy(digest + (i * sizeof(uint32_t)), &dsg, sizeof(uint32_t));
+	}
+
+#if defined(IMAGE_BL2)
+	/*
+	 * Clean hardware context as HASH could be used later
+	 * by non-secure software
+	 */
+	hash_hw_init(HASH_SHA256);
+#endif
+	return 0;
+}
+
+int stm32_hash_update(const uint8_t *buffer, size_t length)
+{
+	size_t remain_length = length;
+	int ret = 0;
+
+	if ((length == 0U) || (buffer == NULL)) {
+		return 0;
+	}
+
+	stm32mp_clk_enable(stm32_hash.clock);
+
+	if (stm32_remain.length != 0U) {
+		uint32_t copysize;
+
+		copysize = MIN((sizeof(uint32_t) - stm32_remain.length),
+			       length);
+		memcpy(((uint8_t *)&stm32_remain.buffer) + stm32_remain.length,
+		       buffer, copysize);
+		remain_length -= copysize;
+		buffer += copysize;
+		if (stm32_remain.length == sizeof(uint32_t)) {
+			ret = hash_write_data(stm32_remain.buffer);
+			if (ret != 0) {
+				goto exit;
+			}
+
+			zeromem(&stm32_remain, sizeof(stm32_remain));
+		}
+	}
+
+	while (remain_length / sizeof(uint32_t) != 0U) {
+		uint32_t tmp_buf;
+
+		memcpy(&tmp_buf, buffer, sizeof(uint32_t));
+		ret = hash_write_data(tmp_buf);
+		if (ret != 0) {
+			goto exit;
+		}
+
+		buffer += sizeof(uint32_t);
+		remain_length -= sizeof(uint32_t);
+	}
+
+	if (remain_length != 0U) {
+		assert(stm32_remain.length == 0U);
+
+		memcpy((uint8_t *)&stm32_remain.buffer, buffer, remain_length);
+		stm32_remain.length = remain_length;
+	}
+
+exit:
+	stm32mp_clk_disable(stm32_hash.clock);
+
+	return ret;
+}
+
+int stm32_hash_final(uint8_t *digest)
+{
+	int ret;
+
+	stm32mp_clk_enable(stm32_hash.clock);
+
+	if (stm32_remain.length != 0U) {
+		ret = hash_write_data(stm32_remain.buffer);
+		if (ret != 0) {
+			stm32mp_clk_disable(stm32_hash.clock);
+			return ret;
+		}
+
+		mmio_clrsetbits_32(hash_base() + HASH_STR, HASH_STR_NBLW_MASK,
+				   8U * stm32_remain.length);
+		zeromem(&stm32_remain, sizeof(stm32_remain));
+	}
+
+	mmio_setbits_32(hash_base() + HASH_STR, HASH_STR_DCAL);
+
+	ret = hash_get_digest(digest);
+
+	stm32mp_clk_disable(stm32_hash.clock);
+
+	return ret;
+}
+
+int stm32_hash_final_update(const uint8_t *buffer, uint32_t length,
+			    uint8_t *digest)
+{
+	int ret;
+
+	ret = stm32_hash_update(buffer, length);
+	if (ret != 0) {
+		return ret;
+	}
+
+	return stm32_hash_final(digest);
+}
+
+void stm32_hash_init(enum stm32_hash_algo_mode mode)
+{
+	stm32mp_clk_enable(stm32_hash.clock);
+
+	hash_hw_init(mode);
+
+	stm32mp_clk_disable(stm32_hash.clock);
+
+	zeromem(&stm32_remain, sizeof(stm32_remain));
+}
+
+int stm32_hash_register(void)
+{
+	struct dt_node_info hash_info;
+	int node;
+
+	for (node = dt_get_node(&hash_info, -1, DT_HASH_COMPAT);
+	     node != -FDT_ERR_NOTFOUND;
+	     node = dt_get_node(&hash_info, node, DT_HASH_COMPAT)) {
+#if defined(IMAGE_BL2)
+		if (hash_info.status != DT_DISABLED) {
+			break;
+		}
+#else
+		if (hash_info.status == DT_SECURE) {
+			break;
+		}
+#endif
+	}
+
+	if (node == -FDT_ERR_NOTFOUND) {
+		return -ENODEV;
+	}
+
+	if (hash_info.clock < 0) {
+		return -EINVAL;
+	}
+
+	stm32_hash.base = hash_info.base;
+	stm32_hash.clock = hash_info.clock;
+
+	stm32mp_clk_enable(stm32_hash.clock);
+
+	if (hash_info.reset >= 0) {
+		stm32mp_reset_assert((unsigned long)hash_info.reset);
+		udelay(20);
+		stm32mp_reset_deassert((unsigned long)hash_info.reset);
+	}
+
+	stm32mp_clk_disable(stm32_hash.clock);
+
+	return 0;
+}

include/drivers/st/stm32_hash.h

+/*
+ * Copyright (c) 2019, STMicroelectronics - All Rights Reserved
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef STM32_HASH_H
+#define STM32_HASH_H
+
+enum stm32_hash_algo_mode {
+	HASH_MD5SUM,
+	HASH_SHA1,
+	HASH_SHA224,
+	HASH_SHA256
+};
+
+int stm32_hash_update(const uint8_t *buffer, uint32_t length);
+int stm32_hash_final(uint8_t *digest);
+int stm32_hash_final_update(const uint8_t *buffer, uint32_t buf_length,
+			    uint8_t *digest);
+void stm32_hash_init(enum stm32_hash_algo_mode mode);
+int stm32_hash_register(void);
+
+#endif /* STM32_HASH_H */