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path: root/drivers/char/hw_random/bcm63xx-rng.c
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Diffstat (limited to 'drivers/char/hw_random/bcm63xx-rng.c')
-rw-r--r--drivers/char/hw_random/bcm63xx-rng.c146
1 files changed, 146 insertions, 0 deletions
diff --git a/drivers/char/hw_random/bcm63xx-rng.c b/drivers/char/hw_random/bcm63xx-rng.c
new file mode 100644
index 000000000..4b31f1387
--- /dev/null
+++ b/drivers/char/hw_random/bcm63xx-rng.c
@@ -0,0 +1,146 @@
+/*
+ * Broadcom BCM63xx Random Number Generator support
+ *
+ * Copyright (C) 2011, Florian Fainelli <florian@openwrt.org>
+ * Copyright (C) 2009, Broadcom Corporation
+ *
+ */
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+#include <linux/err.h>
+#include <linux/clk.h>
+#include <linux/platform_device.h>
+#include <linux/hw_random.h>
+
+#define RNG_CTRL 0x00
+#define RNG_EN (1 << 0)
+
+#define RNG_STAT 0x04
+#define RNG_AVAIL_MASK (0xff000000)
+
+#define RNG_DATA 0x08
+#define RNG_THRES 0x0c
+#define RNG_MASK 0x10
+
+struct bcm63xx_rng_priv {
+ struct hwrng rng;
+ struct clk *clk;
+ void __iomem *regs;
+};
+
+#define to_rng_priv(rng) container_of(rng, struct bcm63xx_rng_priv, rng)
+
+static int bcm63xx_rng_init(struct hwrng *rng)
+{
+ struct bcm63xx_rng_priv *priv = to_rng_priv(rng);
+ u32 val;
+ int error;
+
+ error = clk_prepare_enable(priv->clk);
+ if (error)
+ return error;
+
+ val = __raw_readl(priv->regs + RNG_CTRL);
+ val |= RNG_EN;
+ __raw_writel(val, priv->regs + RNG_CTRL);
+
+ return 0;
+}
+
+static void bcm63xx_rng_cleanup(struct hwrng *rng)
+{
+ struct bcm63xx_rng_priv *priv = to_rng_priv(rng);
+ u32 val;
+
+ val = __raw_readl(priv->regs + RNG_CTRL);
+ val &= ~RNG_EN;
+ __raw_writel(val, priv->regs + RNG_CTRL);
+
+ clk_disable_unprepare(priv->clk);
+}
+
+static int bcm63xx_rng_data_present(struct hwrng *rng, int wait)
+{
+ struct bcm63xx_rng_priv *priv = to_rng_priv(rng);
+
+ return __raw_readl(priv->regs + RNG_STAT) & RNG_AVAIL_MASK;
+}
+
+static int bcm63xx_rng_data_read(struct hwrng *rng, u32 *data)
+{
+ struct bcm63xx_rng_priv *priv = to_rng_priv(rng);
+
+ *data = __raw_readl(priv->regs + RNG_DATA);
+
+ return 4;
+}
+
+static int bcm63xx_rng_probe(struct platform_device *pdev)
+{
+ struct resource *r;
+ struct clk *clk;
+ int ret;
+ struct bcm63xx_rng_priv *priv;
+ struct hwrng *rng;
+
+ r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!r) {
+ dev_err(&pdev->dev, "no iomem resource\n");
+ return -ENXIO;
+ }
+
+ priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->rng.name = pdev->name;
+ priv->rng.init = bcm63xx_rng_init;
+ priv->rng.cleanup = bcm63xx_rng_cleanup;
+ priv->rng.data_present = bcm63xx_rng_data_present;
+ priv->rng.data_read = bcm63xx_rng_data_read;
+
+ priv->clk = devm_clk_get(&pdev->dev, "ipsec");
+ if (IS_ERR(priv->clk)) {
+ ret = PTR_ERR(priv->clk);
+ dev_err(&pdev->dev, "no clock for device: %d\n", ret);
+ return ret;
+ }
+
+ if (!devm_request_mem_region(&pdev->dev, r->start,
+ resource_size(r), pdev->name)) {
+ dev_err(&pdev->dev, "request mem failed");
+ return -EBUSY;
+ }
+
+ priv->regs = devm_ioremap_nocache(&pdev->dev, r->start,
+ resource_size(r));
+ if (!priv->regs) {
+ dev_err(&pdev->dev, "ioremap failed");
+ return -ENOMEM;
+ }
+
+ ret = devm_hwrng_register(&pdev->dev, &priv->rng);
+ if (ret) {
+ dev_err(&pdev->dev, "failed to register rng device: %d\n",
+ ret);
+ return ret;
+ }
+
+ dev_info(&pdev->dev, "registered RNG driver\n");
+
+ return 0;
+}
+
+static struct platform_driver bcm63xx_rng_driver = {
+ .probe = bcm63xx_rng_probe,
+ .driver = {
+ .name = "bcm63xx-rng",
+ },
+};
+
+module_platform_driver(bcm63xx_rng_driver);
+
+MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
+MODULE_DESCRIPTION("Broadcom BCM63xx RNG driver");
+MODULE_LICENSE("GPL");