Merge branch 'for-next/hwrng'

4 files changed, 80 insertions, 0 deletions

diff --git a/commands/Kconfig b/commands/Kconfig
index bc0885c69d..ab8e09aa45 100644
--- a/commands/Kconfig
+++ b/commands/Kconfig
@@ -2115,6 +2115,12 @@ config CMD_SPD_DECODE
 	help
 	  decode spd eeprom
 
+config CMD_SEED
+	tristate
+	prompt "seed"
+	help
+	  Seed the pseudo random number generator (PRNG)
+
 # end Miscellaneous commands
 endmenu
 
diff --git a/commands/Makefile b/commands/Makefile
index 601f15fc38..ab59021562 100644
--- a/commands/Makefile
+++ b/commands/Makefile
@@ -120,3 +120,4 @@ obj-$(CONFIG_CMD_DHRYSTONE)	+= dhrystone.o
 obj-$(CONFIG_CMD_SPD_DECODE)	+= spd_decode.o
 obj-$(CONFIG_CMD_MMC_EXTCSD)	+= mmc_extcsd.o
 obj-$(CONFIG_CMD_NAND_BITFLIP)	+= nand-bitflip.o
+obj-$(CONFIG_CMD_SEED)		+= seed.o
diff --git a/commands/seed.c b/commands/seed.c
new file mode 100644
index 0000000000..e378cd7635
--- /dev/null
+++ b/commands/seed.c
@@ -0,0 +1,44 @@
+/*
+ * (c) 2017 Oleksij Rempel <kernel@pengutronix.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <common.h>
+#include <command.h>
+#include <stdlib.h>
+#include <linux/ctype.h>
+
+static int do_seed(int argc, char *argv[])
+{
+	if (argc < 2)
+		return COMMAND_ERROR_USAGE;
+
+	if (isdigit(*argv[1])) {
+		srand(simple_strtoul(argv[1], NULL, 0));
+		return 0;
+	}
+
+	printf("numerical parameter expected\n");
+	return 1;
+}
+
+BAREBOX_CMD_HELP_START(seed)
+BAREBOX_CMD_HELP_TEXT("Seed the pseudo random number generator")
+BAREBOX_CMD_HELP_END
+
+BAREBOX_CMD_START(seed)
+	.cmd = do_seed,
+	BAREBOX_CMD_DESC("seed the PRNG")
+	BAREBOX_CMD_OPTS("VALUE")
+	BAREBOX_CMD_GROUP(CMD_GRP_MISC)
+	BAREBOX_CMD_HELP(cmd_seed_help)
+BAREBOX_CMD_END
diff --git a/commands/stddev.c b/commands/stddev.c
index 318d057417..93da2c7398 100644
--- a/commands/stddev.c
+++ b/commands/stddev.c
@@ -17,6 +17,7 @@
 
 #include <common.h>
 #include <init.h>
+#include <stdlib.h>
 
 static ssize_t zero_read(struct cdev *cdev, void *buf, size_t count, loff_t offset, ulong flags)
 {
@@ -100,3 +101,31 @@ static int null_init(void)
 }
 
 device_initcall(null_init);
+
+static ssize_t prng_read(struct cdev *cdev, void *buf, size_t count, loff_t offset, ulong flags)
+{
+	get_random_bytes(buf, count);
+	return count;
+}
+
+static struct file_operations prngops = {
+	.read  = prng_read,
+	.lseek = dev_lseek_default,
+};
+
+static int prng_init(void)
+{
+	struct cdev *cdev;
+
+	cdev = xzalloc(sizeof (*cdev));
+
+	cdev->name = "prng";
+	cdev->flags = DEVFS_IS_CHARACTER_DEV;
+	cdev->ops = &prngops;
+
+	devfs_create(cdev);
+
+	return 0;
+}
+
+device_initcall(prng_init);