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path: root/drivers/char/hw_random/exynos-rng.c
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Diffstat (limited to 'drivers/char/hw_random/exynos-rng.c')
-rw-r--r--drivers/char/hw_random/exynos-rng.c58
1 files changed, 49 insertions, 9 deletions
diff --git a/drivers/char/hw_random/exynos-rng.c b/drivers/char/hw_random/exynos-rng.c
index dc4701fd814f..30cf4623184f 100644
--- a/drivers/char/hw_random/exynos-rng.c
+++ b/drivers/char/hw_random/exynos-rng.c
@@ -53,15 +53,11 @@ static void exynos_rng_writel(struct exynos_rng *rng, u32 val, u32 offset)
__raw_writel(val, rng->mem + offset);
}
-static int exynos_init(struct hwrng *rng)
+static int exynos_rng_configure(struct exynos_rng *exynos_rng)
{
- struct exynos_rng *exynos_rng = container_of(rng,
- struct exynos_rng, rng);
int i;
int ret = 0;
- pm_runtime_get_sync(exynos_rng->dev);
-
for (i = 0 ; i < 5 ; i++)
exynos_rng_writel(exynos_rng, jiffies,
EXYNOS_PRNG_SEED_OFFSET + 4*i);
@@ -70,6 +66,17 @@ static int exynos_init(struct hwrng *rng)
& SEED_SETTING_DONE))
ret = -EIO;
+ return ret;
+}
+
+static int exynos_init(struct hwrng *rng)
+{
+ struct exynos_rng *exynos_rng = container_of(rng,
+ struct exynos_rng, rng);
+ int ret = 0;
+
+ pm_runtime_get_sync(exynos_rng->dev);
+ ret = exynos_rng_configure(exynos_rng);
pm_runtime_put_noidle(exynos_rng->dev);
return ret;
@@ -81,21 +88,24 @@ static int exynos_read(struct hwrng *rng, void *buf,
struct exynos_rng *exynos_rng = container_of(rng,
struct exynos_rng, rng);
u32 *data = buf;
+ int retry = 100;
pm_runtime_get_sync(exynos_rng->dev);
exynos_rng_writel(exynos_rng, PRNG_START, 0);
while (!(exynos_rng_readl(exynos_rng,
- EXYNOS_PRNG_STATUS_OFFSET) & PRNG_DONE))
+ EXYNOS_PRNG_STATUS_OFFSET) & PRNG_DONE) && --retry)
cpu_relax();
+ if (!retry)
+ return -ETIMEDOUT;
exynos_rng_writel(exynos_rng, PRNG_DONE, EXYNOS_PRNG_STATUS_OFFSET);
*data = exynos_rng_readl(exynos_rng, EXYNOS_PRNG_OUT1_OFFSET);
pm_runtime_mark_last_busy(exynos_rng->dev);
- pm_runtime_autosuspend(exynos_rng->dev);
+ pm_runtime_put_sync_autosuspend(exynos_rng->dev);
return 4;
}
@@ -152,15 +162,45 @@ static int exynos_rng_runtime_resume(struct device *dev)
return clk_prepare_enable(exynos_rng->clk);
}
+
+static int exynos_rng_suspend(struct device *dev)
+{
+ return pm_runtime_force_suspend(dev);
+}
+
+static int exynos_rng_resume(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct exynos_rng *exynos_rng = platform_get_drvdata(pdev);
+ int ret;
+
+ ret = pm_runtime_force_resume(dev);
+ if (ret)
+ return ret;
+
+ return exynos_rng_configure(exynos_rng);
+}
#endif
-static UNIVERSAL_DEV_PM_OPS(exynos_rng_pm_ops, exynos_rng_runtime_suspend,
- exynos_rng_runtime_resume, NULL);
+static const struct dev_pm_ops exynos_rng_pm_ops = {
+ SET_SYSTEM_SLEEP_PM_OPS(exynos_rng_suspend, exynos_rng_resume)
+ SET_RUNTIME_PM_OPS(exynos_rng_runtime_suspend,
+ exynos_rng_runtime_resume, NULL)
+};
+
+static const struct of_device_id exynos_rng_dt_match[] = {
+ {
+ .compatible = "samsung,exynos4-rng",
+ },
+ { },
+};
+MODULE_DEVICE_TABLE(of, exynos_rng_dt_match);
static struct platform_driver exynos_rng_driver = {
.driver = {
.name = "exynos-rng",
.pm = &exynos_rng_pm_ops,
+ .of_match_table = exynos_rng_dt_match,
},
.probe = exynos_rng_probe,
};