hwrng: exynos - Fix missing configuration after suspend to RAM

[karo-tx-linux.git] / drivers / char / hw_random / exynos-rng.c

diff --git a/drivers/char/hw_random/exynos-rng.c b/drivers/char/hw_random/exynos-rng.c
index dc4701fd814f10aae76bfd852429f89bfe229c46..dc06c78bc1d702cafebb6393b11f7023313c3a38 100644 (file)
--- 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;
 }
@@ -152,10 +162,31 @@ 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 struct platform_driver exynos_rng_driver = {
        .driver         = {