diff options
Diffstat (limited to 'drivers/char/hw_random/omap-rng.c')
| -rw-r--r-- | drivers/char/hw_random/omap-rng.c | 26 |
1 files changed, 13 insertions, 13 deletions
diff --git a/drivers/char/hw_random/omap-rng.c b/drivers/char/hw_random/omap-rng.c index 7e319951fa4..51738bdd834 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 = { |