[PATCH] crypto: caam: rng: convert to hwrng framework

[Steffen Trumtrar]

Convert the i.MX6 CAAM RNG to the HWRNG "framework".

Signed-off-by: Steffen Trumtrar <s.trumtrar at pengutronix.de>
---

 - this patch depends on next and the series
   "HWRNG: add support for HW Random Number Generators"

 drivers/crypto/caam/Kconfig   |  1 +
 drivers/crypto/caam/caamrng.c | 39 ++++++++++++++-------------------------
 2 files changed, 15 insertions(+), 25 deletions(-)

diff --git a/drivers/crypto/caam/Kconfig b/drivers/crypto/caam/Kconfig
index cf05d1c077bb..0a3cb59be4d2 100644
--- a/drivers/crypto/caam/Kconfig
+++ b/drivers/crypto/caam/Kconfig
@@ -29,6 +29,7 @@ config CRYPTO_DEV_FSL_CAAM_RINGSIZE
 config CRYPTO_DEV_FSL_CAAM_RNG
 	bool "Register caam RNG device"
 	depends on CRYPTO_DEV_FSL_CAAM
+	select HWRNG
 	default y
 	help
 	  Selecting this will register the SEC4 hardware rng.
diff --git a/drivers/crypto/caam/caamrng.c b/drivers/crypto/caam/caamrng.c
index 0fef171a2ba9..3358cd0459a4 100644
--- a/drivers/crypto/caam/caamrng.c
+++ b/drivers/crypto/caam/caamrng.c
@@ -35,6 +35,7 @@
 #include <driver.h>
 #include <init.h>
 #include <linux/spinlock.h>
+#include <linux/hw_random.h>
 
 #include "regs.h"
 #include "intern.h"
@@ -116,8 +117,9 @@ static inline int submit_job(struct caam_rng_ctx *ctx, int to_current)
 	return err;
 }
 
-static int caam_read(struct caam_rng_ctx *ctx, void *data, size_t max, bool wait)
+static int caam_read(struct hwrng *rng, void *data, size_t max, bool wait)
 {
+	struct caam_rng_ctx *ctx = (struct caam_rng_ctx *)rng->priv;
 	struct buf_data *bd = &ctx->bufs[ctx->current_buf];
 	int next_buf_idx, copied_idx;
 	int err;
@@ -162,7 +164,7 @@ static int caam_read(struct caam_rng_ctx *ctx, void *data, size_t max, bool wait
 	dev_dbg(ctx->jrdev, "switched to buffer %d\n", ctx->current_buf);
 
 	/* since there already is some data read, don't wait */
-	return copied_idx + caam_read(ctx, data + copied_idx,
+	return copied_idx + caam_read(rng, data + copied_idx,
 				      max - copied_idx, false);
 }
 
@@ -248,29 +250,10 @@ static int caam_init_rng(struct caam_rng_ctx *ctx, struct device_d *jrdev)
 	return 0;
 }
 
-static ssize_t random_read(struct cdev *cdev, void *buf, size_t count,
-			   loff_t offset, ulong flags)
-{
-	struct caam_rng_ctx *ctx = container_of(cdev, struct caam_rng_ctx, cdev);
-
-	return caam_read(ctx, buf, count, true);
-}
-
-static struct file_operations randomops = {
-	.read  = random_read,
-	.lseek = dev_lseek_default,
+static struct hwrng caam_rng_ops = {
+	.read  = caam_read,
 };
 
-static int caam_init_devrandom(struct caam_rng_ctx *ctx, struct device_d *dev)
-{
-	ctx->cdev.name = "hwrng";
-	ctx->cdev.flags = DEVFS_IS_CHARACTER_DEV;
-	ctx->cdev.ops = &randomops;
-	ctx->cdev.dev = dev;
-
-	return devfs_create(&ctx->cdev);
-}
-
 int caam_rng_probe(struct device_d *dev, struct device_d *jrdev)
 {
 	int err;
@@ -281,9 +264,15 @@ int caam_rng_probe(struct device_d *dev, struct device_d *jrdev)
 	if (err)
 		return err;
 
-	err = caam_init_devrandom(rng_ctx, dev);
-	if (err)
+	caam_rng_ops.name = dev->name;
+	caam_rng_ops.priv = (unsigned long)rng_ctx;
+
+	err = hwrng_register(dev, &caam_rng_ops);
+	if (err) {
+		dev_err(dev, "rng-caam registering failed (%d)\n", err);
+
 		return err;
+	}
 
 	dev_info(dev, "registering rng-caam\n");
 
-- 
2.7.0