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authorRomain Perier <romain.perier@free-electrons.com>2016-09-16 12:08:51 +0200
committerHerbert Xu <herbert@gondor.apana.org.au>2016-10-21 10:26:21 +0800
commit69eb4d0190eab9e32fccbe1ec64dec1cfa7fb01a (patch)
treef7f686a3a292d1d43ab92421d98f31cd3f6961ed
parent52060836f79080849dd90e3ae1aeb288411f3def (diff)
hwrng: omap - Switch to non-obsolete read API implementation
The ".data_present" and ".data_read" operations are marked as OBSOLETE in the hwrng API. We have to use the ".read" operation instead. It makes the driver simpler and moves the busy loop, that waits until enough data is generated, to the read function. We simplify this step by only checking the status of the engine, if there is data, we copy the data to the output buffer and the amout of copied data is returned to the caller, otherwise zero is returned. The hwrng core will re-call the read operation as many times as required until enough data has been copied. Signed-off-by: Romain Perier <romain.perier@free-electrons.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
-rw-r--r--drivers/char/hw_random/omap-rng.c41
1 files changed, 17 insertions, 24 deletions
diff --git a/drivers/char/hw_random/omap-rng.c b/drivers/char/hw_random/omap-rng.c
index f5c26a5..6ba0794 100644
--- a/drivers/char/hw_random/omap-rng.c
+++ b/drivers/char/hw_random/omap-rng.c
@@ -140,41 +140,35 @@ static inline void omap_rng_write(struct omap_rng_dev *priv, u16 reg,
__raw_writel(val, priv->base + priv->pdata->regs[reg]);
}
-static int omap_rng_data_present(struct hwrng *rng, int wait)
+
+static int omap_rng_do_read(struct hwrng *rng, void *data, size_t max,
+ bool wait)
{
struct omap_rng_dev *priv;
- int data, i;
+ int i, present;
priv = (struct omap_rng_dev *)rng->priv;
+ if (max < priv->pdata->data_size)
+ return 0;
+
for (i = 0; i < 20; i++) {
- data = priv->pdata->data_present(priv);
- if (data || !wait)
+ present = priv->pdata->data_present(priv);
+ if (present || !wait)
break;
- /* RNG produces data fast enough (2+ MBit/sec, even
- * during "rngtest" loads, that these delays don't
- * seem to trigger. We *could* use the RNG IRQ, but
- * that'd be higher overhead ... so why bother?
- */
+
udelay(10);
}
- return data;
-}
-
-static int omap_rng_data_read(struct hwrng *rng, u32 *data)
-{
- struct omap_rng_dev *priv;
- u32 data_size, i;
-
- priv = (struct omap_rng_dev *)rng->priv;
- data_size = priv->pdata->data_size;
+ if (!present)
+ return 0;
- for (i = 0; i < data_size / sizeof(u32); i++)
- data[i] = omap_rng_read(priv, RNG_OUTPUT_L_REG + i);
+ memcpy_fromio(data, priv->base + priv->pdata->regs[RNG_OUTPUT_L_REG],
+ priv->pdata->data_size);
if (priv->pdata->regs[RNG_INTACK_REG])
omap_rng_write(priv, RNG_INTACK_REG, RNG_REG_INTACK_RDY_MASK);
- return data_size;
+
+ return priv->pdata->data_size;
}
static int omap_rng_init(struct hwrng *rng)
@@ -195,8 +189,7 @@ static void omap_rng_cleanup(struct hwrng *rng)
static struct hwrng omap_rng_ops = {
.name = "omap",
- .data_present = omap_rng_data_present,
- .data_read = omap_rng_data_read,
+ .read = omap_rng_do_read,
.init = omap_rng_init,
.cleanup = omap_rng_cleanup,
};