1 files changed, 141 insertions, 0 deletions

diff --git a/drivers/char/hw_random/omap3-rom-rng.c b/drivers/char/hw_random/omap3-rom-rng.c
new file mode 100644
index 000000000000..c853e9e68573
--- /dev/null
+++ b/drivers/char/hw_random/omap3-rom-rng.c
@@ -0,0 +1,141 @@
+/*
+ * omap3-rom-rng.c - RNG driver for TI OMAP3 CPU family
+ *
+ * Copyright (C) 2009 Nokia Corporation
+ * Author: Juha Yrjola <juha.yrjola@solidboot.com>
+ *
+ * Copyright (C) 2013 Pali Rohár <pali.rohar@gmail.com>
+ *
+ * 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.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/random.h>
+#include <linux/hw_random.h>
+#include <linux/timer.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/platform_device.h>
+
+#define RNG_RESET                       0x01
+#define RNG_GEN_PRNG_HW_INIT            0x02
+#define RNG_GEN_HW                      0x08
+
+/* param1: ptr, param2: count, param3: flag */
+static u32 (*omap3_rom_rng_call)(u32, u32, u32);
+
+static struct timer_list idle_timer;
+static int rng_idle;
+static struct clk *rng_clk;
+
+static void omap3_rom_rng_idle(unsigned long data)
+{
+        int r;
+
+        r = omap3_rom_rng_call(0, 0, RNG_RESET);
+        if (r != 0) {
+                pr_err("reset failed: %d\n", r);
+                return;
+        }
+        clk_disable_unprepare(rng_clk);
+        rng_idle = 1;
+}
+
+static int omap3_rom_rng_get_random(void *buf, unsigned int count)
+{
+        u32 r;
+        u32 ptr;
+
+        del_timer_sync(&idle_timer);
+        if (rng_idle) {
+                clk_prepare_enable(rng_clk);
+                r = omap3_rom_rng_call(0, 0, RNG_GEN_PRNG_HW_INIT);
+                if (r != 0) {
+                        clk_disable_unprepare(rng_clk);
+                        pr_err("HW init failed: %d\n", r);
+                        return -EIO;
+                }
+                rng_idle = 0;
+        }
+
+        ptr = virt_to_phys(buf);
+        r = omap3_rom_rng_call(ptr, count, RNG_GEN_HW);
+        mod_timer(&idle_timer, jiffies + msecs_to_jiffies(500));
+        if (r != 0)
+                return -EINVAL;
+        return 0;
+}
+
+static int omap3_rom_rng_data_present(struct hwrng *rng, int wait)
+{
+        return 1;
+}
+
+static int omap3_rom_rng_data_read(struct hwrng *rng, u32 *data)
+{
+        int r;
+
+        r = omap3_rom_rng_get_random(data, 4);
+        if (r < 0)
+                return r;
+        return 4;
+}
+
+static struct hwrng omap3_rom_rng_ops = {
+        .name           = "omap3-rom",
+        .data_present   = omap3_rom_rng_data_present,
+        .data_read      = omap3_rom_rng_data_read,
+};
+
+static int omap3_rom_rng_probe(struct platform_device *pdev)
+{
+        pr_info("initializing\n");
+
+        omap3_rom_rng_call = pdev->dev.platform_data;
+        if (!omap3_rom_rng_call) {
+                pr_err("omap3_rom_rng_call is NULL\n");
+                return -EINVAL;
+        }
+
+        setup_timer(&idle_timer, omap3_rom_rng_idle, 0);
+        rng_clk = clk_get(&pdev->dev, "ick");
+        if (IS_ERR(rng_clk)) {
+                pr_err("unable to get RNG clock\n");
+                return PTR_ERR(rng_clk);
+        }
+
+        /* Leave the RNG in reset state. */
+        clk_prepare_enable(rng_clk);
+        omap3_rom_rng_idle(0);
+
+        return hwrng_register(&omap3_rom_rng_ops);
+}
+
+static int omap3_rom_rng_remove(struct platform_device *pdev)
+{
+        hwrng_unregister(&omap3_rom_rng_ops);
+        clk_disable_unprepare(rng_clk);
+        clk_put(rng_clk);
+        return 0;
+}
+
+static struct platform_driver omap3_rom_rng_driver = {
+        .driver = {
+                .name           = "omap3-rom-rng",
+                .owner          = THIS_MODULE,
+        },
+        .probe          = omap3_rom_rng_probe,
+        .remove         = omap3_rom_rng_remove,
+};
+
+module_platform_driver(omap3_rom_rng_driver);
+
+MODULE_ALIAS("platform:omap3-rom-rng");
+MODULE_AUTHOR("Juha Yrjola");
+MODULE_AUTHOR("Pali Rohár <pali.rohar@gmail.com>");
+MODULE_LICENSE("GPL");