hwrng: timeriomem - New driver
Some hardware platforms, the TS-7800[1] is one for example, can
supply the kernel with an entropy source, albeit a slow one for
TS-7800 users, by just reading a particular IO address. This
source must not be read above a certain rate otherwise the quality
suffers.
The driver is then hooked into by calling
platform_device_(register|add|del) passing a structure similar to:
------
static struct timeriomem_rng_data ts78xx_ts_rng_data = {
.address = (u32 *__iomem) TS_RNG,
.period = 1000000, /* one second */
};
static struct platform_device ts78xx_ts_rng_device = {
.name = "timeriomem_rng",
.id = -1,
.dev = {
.platform_data = &ts78xx_ts_rng_data,
},
.num_resources = 0,
};
------
[1] http://www.embeddedarm.com/products/board-detail.php?product=TS-7800
Signed-off-by: Alexander Clouter <[email protected]>
Signed-off-by: Herbert Xu <[email protected]>
diff --git a/include/linux/timeriomem-rng.h b/include/linux/timeriomem-rng.h
new file mode 100644
index 0000000..dd25317
--- /dev/null
+++ b/include/linux/timeriomem-rng.h
@@ -0,0 +1,21 @@
+/*
+ * linux/include/linux/timeriomem-rng.h
+ *
+ * Copyright (c) 2009 Alexander Clouter <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/completion.h>
+
+struct timeriomem_rng_data {
+ struct completion completion;
+ unsigned int present:1;
+
+ u32 __iomem *address;
+
+ /* measures in usecs */
+ unsigned int period;
+};
