rngb: add the support for TRNG for imx6ull

The driver starts by creating basic structures for a phonix driver.
Then it sets flags for tests of rngb and seeding, sequentially.
The last things is waiting for system messaga.

JIRA: RTOS-317

Author: bswiercz

_targets/Makefile.armv7a7-imx6ull

@@ -6,7 +6,7 @@
 # Copyright 2019 Phoenix Systems
 #
 
-DEFAULT_COMPONENTS := imx6ull-sdma imx6ull-gpio libimx6ull-ecspi libimx6ull-qspi
+DEFAULT_COMPONENTS := imx6ull-sdma imx6ull-gpio imx6ull-rngb libimx6ull-ecspi libimx6ull-qspi
 DEFAULT_COMPONENTS += imx6ull-flash
 DEFAULT_COMPONENTS += imx6ull-flashnor
 DEFAULT_COMPONENTS += libusbclient cdc-demo

random/Makefile

@@ -0,0 +1,10 @@
+#
+# Makefile for Phoenix-RTOS rngb
+#
+# Copyright 2023 Phoenix Systems
+#
+
+NAME := imx6ull-rngb
+LOCAL_SRCS := imx6ull-rngb.c
+
+include $(binary.mk)

random/imx6ull-rngb.c

@@ -0,0 +1,305 @@
+/*
+ * Phoenix-RTOS
+ *
+ * i.MX 6ULL RNGB driver
+ *
+ * Copyright 2023 Phoenix Systems
+ * Author: Dawid Szpejna
+ *
+ * This file is part of Phoenix-RTOS.
+ *
+ * %LICENSE%
+ */
+
+#include <string.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <posix/utils.h>
+#include <sys/debug.h>
+#include <sys/platform.h>
+#include <sys/interrupt.h>
+#include <sys/threads.h>
+#include <sys/mman.h>
+#include <sys/msg.h>
+
+
+enum { rng_ver = 0,
+	rng_cmd,
+	rng_cr,
+	rng_sr,
+	rng_esr,
+	rng_out };
+
+
+#define RNGB_START_ADDRESS 0x02284000
+#define RNGB_IRQ           (6 + 32)
+
+
+#define SELF_TEST_DONE 1U
+#define SEED_DONE      2U
+#define ERROR_OCCURRED 4U
+#define MMAP_SIZE      4096
+
+
+/* intr_st indicates status of interrupts */
+static struct {
+	volatile uint32_t *base;
+	volatile uint32_t intr_st;
+	uint32_t port;
+
+	handle_t lock;
+	handle_t cond;
+} common_rngb;
+
+
+static int rngb_intr(unsigned int n, void *arg)
+{
+	uint32_t status = *(common_rngb.base + rng_sr);
+
+	/* Self tests are done */
+	if ((status & 0x10) != 0) {
+		common_rngb.intr_st |= SELF_TEST_DONE;
+	}
+
+	/* Seeding is done*/
+	if ((status & 0x20) != 0) {
+		common_rngb.intr_st |= SEED_DONE;
+	}
+
+	/* An error occurred*/
+	if ((status & (1 << 16)) != 0) {
+		common_rngb.intr_st |= ERROR_OCCURRED;
+	}
+
+	/* Clear interrupt */
+	*(common_rngb.base + rng_cmd) = 0x20;
+	return 1;
+}
+
+
+static void systemCleanup(int level)
+{
+	if (level > 3) {
+		resourceDestroy(common_rngb.cond);
+	}
+
+	if (level > 2) {
+		resourceDestroy(common_rngb.lock);
+	}
+
+	if (level > 1) {
+		portDestroy(common_rngb.port);
+	}
+
+	if (level > 0) {
+		munmap((void *)common_rngb.base, MMAP_SIZE);
+	}
+}
+
+
+static int systemInit(void)
+{
+	const char devpath[] = "random";
+	int err;
+	oid_t dev;
+
+	common_rngb.base = mmap(NULL, MMAP_SIZE, PROT_READ | PROT_WRITE, MAP_DEVICE, OID_PHYSMEM, RNGB_START_ADDRESS);
+	if (common_rngb.base == MAP_FAILED) {
+		printf("rngb: could not map addr\n");
+		return -1;
+	}
+
+	err = portCreate(&common_rngb.port);
+	if (err != EOK) {
+		printf("rngb: could not create port\n");
+		systemCleanup(1);
+		return -1;
+	}
+
+	dev.port = common_rngb.port;
+	dev.id = 0;
+
+	err = mutexCreate(&common_rngb.lock);
+	if (err != EOK) {
+		printf("rngb: could not create mutex for rngb\n");
+		systemCleanup(2);
+		return -1;
+	}
+
+	err = condCreate(&common_rngb.cond);
+	if (err != EOK) {
+		printf("rngb: could not create cond for rngb\n");
+		systemCleanup(3);
+		return -1;
+	}
+
+	err = create_dev(&dev, devpath);
+	if (err != EOK) {
+		printf("rngb: could not create port file %s (err %d)\n", devpath, err);
+		systemCleanup(4);
+		return -1;
+	}
+
+	return 0;
+}
+
+
+static int hardwareInit(void)
+{
+	int err;
+
+	/* Reset and wait until rngb is sleeping */
+	*(common_rngb.base + rng_cmd) = 0x40;
+	do {
+		err = *(common_rngb.base + rng_sr) & 0x4;
+	} while (err == 0);
+
+	interrupt(RNGB_IRQ, rngb_intr, NULL, common_rngb.cond, NULL);
+
+	/* Run self test */
+	*(common_rngb.base + rng_cmd) = 0x1;
+	mutexLock(common_rngb.lock);
+	while (common_rngb.intr_st == 0) {
+		condWait(common_rngb.cond, common_rngb.lock, 3000);
+	}
+	mutexUnlock(common_rngb.lock);
+
+	if ((common_rngb.intr_st & ERROR_OCCURRED) != 0) {
+		printf("rngb: self-test failed\n");
+
+		systemCleanup(4);
+		return -1;
+	}
+
+	common_rngb.intr_st = 0;
+
+	/* Run seeding */
+	*(common_rngb.base + rng_cmd) = 0x2;
+	mutexLock(common_rngb.lock);
+	while (common_rngb.intr_st == 0) {
+		condWait(common_rngb.cond, common_rngb.lock, 3000);
+	}
+	mutexUnlock(common_rngb.lock);
+
+	if ((common_rngb.intr_st & ERROR_OCCURRED) != 0) {
+		printf("rngb: error after generating seed\n");
+
+		systemCleanup(4);
+		return -1;
+	}
+
+	common_rngb.intr_st = 0;
+
+	/* Enable automatic seeding */
+	*(common_rngb.base + rng_cr) = 0x10;
+
+	printf("imx6ull-rngb: initialized\n");
+
+	return 0;
+}
+
+
+static int readRandoms(char *buff, size_t size, unsigned mode)
+{
+	union {
+		uint32_t val32;
+		char val8[sizeof(uint32_t)];
+	} reg;
+	unsigned int i;
+	int status;
+
+	if (size == 0) {
+		return 0;
+	}
+
+	mutexLock(common_rngb.lock);
+	i = 0;
+	while (i < size) {
+		if ((i % sizeof(uint32_t)) == 0) {
+			status = *(common_rngb.base + rng_sr);
+			if (((status >> 16) & 1U) == 1) {
+				mutexUnlock(common_rngb.lock);
+				return -EIO;
+			}
+			if (((status >> 8) & 0xf) == 0) {
+				if ((mode & O_NONBLOCK) != 0) {
+					break;
+				}
+				/* wait for new values in FIFO */
+				continue;
+			}
+			reg.val32 = *(common_rngb.base + rng_out);
+		}
+		buff[i] = reg.val8[i % sizeof(uint32_t)];
+		i++;
+	}
+	mutexUnlock(common_rngb.lock);
+
+	return i == 0 ? -EAGAIN : i;
+}
+
+
+static void handleMsg(void *arg)
+{
+	msg_t msg;
+	unsigned long int rid;
+	int err;
+
+	while (1) {
+		err = msgRecv(common_rngb.port, &msg, &rid);
+		if (err < 0) {
+			if (err == -EINTR) {
+				continue;
+			}
+			else {
+				printf("rngb: msgRecv returned error: %s\n", strerror(-err));
+				break;
+			}
+		}
+
+		switch (msg.type) {
+			case mtClose:
+			case mtOpen:
+				msg.o.io.err = msg.i.openclose.oid.id != 0 ? -ENOENT : EOK;
+				break;
+
+			case mtRead:
+				if (msg.o.data != NULL) {
+					msg.o.io.err = readRandoms(msg.o.data, msg.o.size > 512 ? 512 : msg.o.size, msg.i.io.mode);
+				}
+				else {
+					msg.o.io.err = -EINVAL;
+				}
+				break;
+
+			default:
+				msg.o.io.err = -EINVAL;
+				break;
+		}
+
+		msgRespond(common_rngb.port, &msg, rid);
+	}
+}
+
+
+int main(int argc, char **argv)
+{
+	oid_t root;
+	(void)argc;
+	(void)argv;
+
+	while (lookup("/", NULL, &root) < 0) {
+		usleep(10000);
+	}
+
+	if (systemInit() || hardwareInit()) {
+		return EIO;
+	}
+
+	handleMsg(NULL);
+
+	return 0;
+}