From c49a7f182c44c31ea460093eb263110824f6c98e Mon Sep 17 00:00:00 2001
From: David Brownell <dbrownell@users.sourceforge.net>
Date: Wed, 16 Apr 2008 19:24:42 +0800
Subject: [PATCH] [HWRNG] omap: Minor updates
Minor cleanups to the OMAP RNG:
- Comment update re RNG status:
* yes, it works on 16xx; "rngtest" is quite happy
* it's fast enough that polling vs IRQ is a non-issue
- Get rid of BUG_ON
- Help GCC not be stupid about inlining (object code shrink)
- Remove "sparse" warning
- Cope with new hotplug rule requiring "platform:" modalias
And make the file header match kernel conventions.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
---
drivers/char/hw_random/omap-rng.c | 26 +++++++++++++-------------
1 file changed, 13 insertions(+), 13 deletions(-)
diff --git a/drivers/char/hw_random/omap-rng.c b/drivers/char/hw_random/omap-rng.c
index 7e319951fa4111..51738bdd834ecc 100644
--- a/drivers/char/hw_random/omap-rng.c
+++ b/drivers/char/hw_random/omap-rng.c
@@ -1,7 +1,5 @@
/*
- * drivers/char/hw_random/omap-rng.c
- *
- * RNG driver for TI OMAP CPU family
+ * omap-rng.c - RNG driver for TI OMAP CPU family
*
* Author: Deepak Saxena <dsaxena@plexity.net>
*
@@ -15,11 +13,6 @@
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
- *
- * TODO:
- *
- * - Make status updated be interrupt driven so we don't poll
- *
*/
#include <linux/module.h>
@@ -55,17 +48,16 @@ static void __iomem *rng_base;
static struct clk *rng_ick;
static struct platform_device *rng_dev;
-static u32 omap_rng_read_reg(int reg)
+static inline u32 omap_rng_read_reg(int reg)
{
return __raw_readl(rng_base + reg);
}
-static void omap_rng_write_reg(int reg, u32 val)
+static inline void omap_rng_write_reg(int reg, u32 val)
{
__raw_writel(val, rng_base + reg);
}
-/* REVISIT: Does the status bit really work on 16xx? */
static int omap_rng_data_present(struct hwrng *rng, int wait)
{
int data, i;
@@ -74,6 +66,11 @@ static int omap_rng_data_present(struct hwrng *rng, int wait)
data = omap_rng_read_reg(RNG_STAT_REG) ? 0 : 1;
if (data || !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;
@@ -101,7 +98,8 @@ static int __init omap_rng_probe(struct platform_device *pdev)
* A bit ugly, and it will never actually happen but there can
* be only one RNG and this catches any bork
*/
- BUG_ON(rng_dev);
+ if (rng_dev)
+ return -EBUSY;
if (cpu_is_omap24xx()) {
rng_ick = clk_get(NULL, "rng_ick");
@@ -124,7 +122,7 @@ static int __init omap_rng_probe(struct platform_device *pdev)
return -EBUSY;
dev_set_drvdata(&pdev->dev, mem);
- rng_base = (u32 __iomem *)io_p2v(res->start);
+ rng_base = (u32 __force __iomem *)io_p2v(res->start);
ret = hwrng_register(&omap_rng_ops);
if (ret) {
@@ -182,6 +180,8 @@ static int omap_rng_resume(struct platform_device *pdev)
#endif
+/* work with hotplug and coldplug */
+MODULE_ALIAS("platform:omap_rng");
static struct platform_driver omap_rng_driver = {
.driver = {
--
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