feat(mt8188): add MT8188 TRNG driver
Add MTK TRNG driver for MT8188.
Change-Id: I604edd42ffce9a153e209a015ba454b51da454e1
diff --git a/plat/mediatek/drivers/rng/mt8188/rng_plat.c b/plat/mediatek/drivers/rng/mt8188/rng_plat.c
new file mode 100644
index 0000000..361be22
--- /dev/null
+++ b/plat/mediatek/drivers/rng/mt8188/rng_plat.c
@@ -0,0 +1,96 @@
+/*
+ * Copyright (c) 2024, MediaTek Inc. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <assert.h>
+#include <stdbool.h>
+#include <stdint.h>
+
+#include <common/debug.h>
+#include <drivers/delay_timer.h>
+#include <lib/mmio.h>
+#include <lib/smccc.h>
+#include <plat/common/platform.h>
+#include <platform_def.h>
+#include <services/trng_svc.h>
+#include <smccc_helpers.h>
+
+#include "rng_plat.h"
+
+static void trng_external_swrst(void)
+{
+ /* External swrst to reset whole rng module */
+ mmio_setbits_32(TRNG_SWRST_SET_REG, RNG_SWRST_B);
+ mmio_setbits_32(TRNG_SWRST_CLR_REG, RNG_SWRST_B);
+
+ /* Disable irq */
+ mmio_clrbits_32(RNG_IRQ_CFG, IRQ_EN);
+ /* Set default cutoff value */
+ mmio_write_32(RNG_HTEST, RNG_DEFAULT_CUTOFF);
+ /* Enable rng */
+ mmio_setbits_32(RNG_EN, DRBG_EN | NRBG_EN);
+}
+
+static bool get_entropy_32(uint32_t *out)
+{
+ uint64_t time = timeout_init_us(MTK_TIMEOUT_POLL);
+ int retry_times = 0;
+
+ while (!(mmio_read_32(RNG_STATUS) & DRBG_VALID)) {
+ if (mmio_read_32(RNG_STATUS) & (RNG_ERROR | APB_ERROR)) {
+ mmio_clrbits_32(RNG_EN, DRBG_EN | NRBG_EN);
+
+ mmio_clrbits_32(RNG_SWRST, SWRST_B);
+ mmio_setbits_32(RNG_SWRST, SWRST_B);
+
+ mmio_setbits_32(RNG_EN, DRBG_EN | NRBG_EN);
+ }
+
+ if (timeout_elapsed(time)) {
+ trng_external_swrst();
+ time = timeout_init_us(MTK_TIMEOUT_POLL);
+ retry_times++;
+ }
+
+ if (retry_times > MTK_RETRY_CNT) {
+ ERROR("%s: trng NOT ready\n", __func__);
+ return false;
+ }
+ }
+
+ *out = mmio_read_32(RNG_OUT);
+
+ return true;
+}
+
+/* Get random number from HWRNG and return 8 bytes of entropy.
+ * Return 'true' when random value generated successfully, otherwise return
+ * 'false'.
+ */
+bool plat_get_entropy(uint64_t *out)
+{
+ uint32_t seed[2] = { 0 };
+ int i = 0;
+
+ assert(out);
+ assert(!check_uptr_overflow((uintptr_t)out, sizeof(*out)));
+
+ /* Disable interrupt mode */
+ mmio_clrbits_32(RNG_IRQ_CFG, IRQ_EN);
+ /* Set rng health test cutoff value */
+ mmio_write_32(RNG_HTEST, RNG_DEFAULT_CUTOFF);
+ /* Enable rng module */
+ mmio_setbits_32(RNG_EN, DRBG_EN | NRBG_EN);
+
+ for (i = 0; i < ARRAY_SIZE(seed); i++) {
+ if (!get_entropy_32(&seed[i]))
+ return false;
+ }
+
+ /* Output 8 bytes entropy by combining 2 32-bit random numbers. */
+ *out = ((uint64_t)seed[0] << 32) | seed[1];
+
+ return true;
+}
diff --git a/plat/mediatek/drivers/rng/mt8188/rng_plat.h b/plat/mediatek/drivers/rng/mt8188/rng_plat.h
new file mode 100644
index 0000000..37ef271
--- /dev/null
+++ b/plat/mediatek/drivers/rng/mt8188/rng_plat.h
@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2024, MediaTek Inc. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef RNG_PLAT_H
+#define RNG_PLAT_H
+
+#include <lib/utils_def.h>
+
+#define MTK_TIMEOUT_POLL 1000
+
+#define MTK_RETRY_CNT 10
+
+#define RNG_DEFAULT_CUTOFF 0x04871C0B
+
+/*******************************************************************************
+ * TRNG related constants
+ ******************************************************************************/
+#define RNG_STATUS (TRNG_BASE + 0x0004)
+#define RNG_SWRST (TRNG_BASE + 0x0010)
+#define RNG_IRQ_CFG (TRNG_BASE + 0x0014)
+#define RNG_EN (TRNG_BASE + 0x0020)
+#define RNG_HTEST (TRNG_BASE + 0x0028)
+#define RNG_OUT (TRNG_BASE + 0x0030)
+#define RNG_RAW (TRNG_BASE + 0x0038)
+#define RNG_SRC (TRNG_BASE + 0x0050)
+
+#define RAW_VALID BIT(12)
+#define DRBG_VALID BIT(4)
+#define RAW_EN BIT(8)
+#define NRBG_EN BIT(4)
+#define DRBG_EN BIT(0)
+#define IRQ_EN BIT(0)
+#define SWRST_B BIT(0)
+/* Error conditions */
+#define RNG_ERROR GENMASK_32(28, 24)
+#define APB_ERROR BIT(16)
+
+/* External swrst */
+#define TRNG_SWRST_SET_REG (INFRACFG_AO_BASE + 0x150)
+#define TRNG_SWRST_CLR_REG (INFRACFG_AO_BASE + 0x154)
+#define RNG_SWRST_B BIT(13)
+
+#endif /* RNG_PLAT_H */