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@@ -0,0 +1,131 @@
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+/*
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+ * Generic PowerPC 44x RNG driver
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+ *
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+ * Copyright 2011 IBM Corporation
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+ *
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+ * This program is free software; you can redistribute it and/or modify it
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+ * under the terms of the GNU General Public License as published by the
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+ * Free Software Foundation; version 2 of the License.
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+ */
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+
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+#include <linux/module.h>
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+#include <linux/kernel.h>
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+#include <linux/interrupt.h>
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+#include <linux/platform_device.h>
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+#include <linux/hw_random.h>
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+#include <linux/delay.h>
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+#include <linux/of_address.h>
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+#include <linux/of_platform.h>
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+#include <linux/io.h>
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+
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+#include "crypto4xx_core.h"
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+#include "crypto4xx_trng.h"
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+#include "crypto4xx_reg_def.h"
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+
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+#define PPC4XX_TRNG_CTRL 0x0008
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+#define PPC4XX_TRNG_CTRL_DALM 0x20
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+#define PPC4XX_TRNG_STAT 0x0004
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+#define PPC4XX_TRNG_STAT_B 0x1
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+#define PPC4XX_TRNG_DATA 0x0000
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+
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+static int ppc4xx_trng_data_present(struct hwrng *rng, int wait)
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+{
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+ struct crypto4xx_device *dev = (void *)rng->priv;
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+ int busy, i, present = 0;
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+
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+ for (i = 0; i < 20; i++) {
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+ busy = (in_le32(dev->trng_base + PPC4XX_TRNG_STAT) &
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+ PPC4XX_TRNG_STAT_B);
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+ if (!busy || !wait) {
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+ present = 1;
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+ break;
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+ }
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+ udelay(10);
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+ }
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+ return present;
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+}
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+
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+static int ppc4xx_trng_data_read(struct hwrng *rng, u32 *data)
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+{
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+ struct crypto4xx_device *dev = (void *)rng->priv;
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+ *data = in_le32(dev->trng_base + PPC4XX_TRNG_DATA);
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+ return 4;
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+}
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+
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+static void ppc4xx_trng_enable(struct crypto4xx_device *dev, bool enable)
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+{
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+ u32 device_ctrl;
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+
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+ device_ctrl = readl(dev->ce_base + CRYPTO4XX_DEVICE_CTRL);
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+ if (enable)
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+ device_ctrl |= PPC4XX_TRNG_EN;
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+ else
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+ device_ctrl &= ~PPC4XX_TRNG_EN;
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+ writel(device_ctrl, dev->ce_base + CRYPTO4XX_DEVICE_CTRL);
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+}
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+
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+static const struct of_device_id ppc4xx_trng_match[] = {
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+ { .compatible = "ppc4xx-rng", },
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+ { .compatible = "amcc,ppc460ex-rng", },
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+ { .compatible = "amcc,ppc440epx-rng", },
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+ {},
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+};
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+
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+void ppc4xx_trng_probe(struct crypto4xx_core_device *core_dev)
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+{
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+ struct crypto4xx_device *dev = core_dev->dev;
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+ struct device_node *trng = NULL;
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+ struct hwrng *rng = NULL;
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+ int err;
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+
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+ /* Find the TRNG device node and map it */
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+ trng = of_find_matching_node(NULL, ppc4xx_trng_match);
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+ if (!trng || !of_device_is_available(trng))
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+ return;
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+
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+ dev->trng_base = of_iomap(trng, 0);
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+ of_node_put(trng);
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+ if (!dev->trng_base)
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+ goto err_out;
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+
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+ rng = kzalloc(sizeof(*rng), GFP_KERNEL);
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+ if (!rng)
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+ goto err_out;
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+
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+ rng->name = MODULE_NAME;
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+ rng->data_present = ppc4xx_trng_data_present;
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+ rng->data_read = ppc4xx_trng_data_read;
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+ rng->priv = (unsigned long) dev;
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+ core_dev->trng = rng;
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+ ppc4xx_trng_enable(dev, true);
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+ out_le32(dev->trng_base + PPC4XX_TRNG_CTRL, PPC4XX_TRNG_CTRL_DALM);
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+ err = devm_hwrng_register(core_dev->device, core_dev->trng);
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+ if (err) {
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+ ppc4xx_trng_enable(dev, false);
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+ dev_err(core_dev->device, "failed to register hwrng (%d).\n",
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+ err);
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+ goto err_out;
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+ }
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+ return;
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+
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+err_out:
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+ of_node_put(trng);
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+ iounmap(dev->trng_base);
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+ kfree(rng);
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+ dev->trng_base = NULL;
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+ core_dev->trng = NULL;
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+}
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+
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+void ppc4xx_trng_remove(struct crypto4xx_core_device *core_dev)
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+{
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+ if (core_dev && core_dev->trng) {
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+ struct crypto4xx_device *dev = core_dev->dev;
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+
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+ devm_hwrng_unregister(core_dev->device, core_dev->trng);
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+ ppc4xx_trng_enable(dev, false);
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+ iounmap(dev->trng_base);
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+ kfree(core_dev->trng);
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+ }
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+}
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+
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+MODULE_ALIAS("ppc4xx_rng");
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