1 files changed, 336 insertions, 0 deletions
diff --git a/drivers/char/hw_random/trng4xx.c b/drivers/char/hw_random/trng4xx.c
new file mode 100644
index 00000000000..ece45e74aa1
--- /dev/null
+++ b/drivers/char/hw_random/trng4xx.c
@@ -0,0 +1,336 @@
+/**
+ *
+ * Copyright (c) 2008 Loc Ho <spulijala@amcc.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * Detail Description:
+ * This file AMCC TRNG offload Linux device driver
+ *
+ * @file trng4xx.c
+ *
+ *
+ */
+#include <linux/version.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/of_platform.h>
+#include <linux/hw_random.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <crypto/trng4xx.h>
+
+#define TRNG4XX_VER_STR	"0.1"
+#define TRNG4XX_HDR	"TRNG4XX: "
+
+/* #define TRNG4XX_DEBUG */
+
+#if !defined(TRNG4XX_DEBUG)
+#	define TRNG4XX_LOG(fmt, ...)
+#else
+#	define TRNG4XX_LOG(fmt, ...)		\
+		do { \
+			printk(KERN_INFO TRNG4XX_HDR fmt "\n", ##__VA_ARGS__); \
+} while(0);
+#endif
+
+struct trng4xx_dev {
+	struct resource 	res;
+	u32			irq;
+	volatile char __iomem   *csr;
+	struct semaphore        access_prot;
+	u32	datum;
+};
+
+struct hal_config {
+	struct of_device 	*ofdev;
+};
+
+static struct trng4xx_dev	trng4xx_dev;
+
+static irqreturn_t trng4xx_irq_handler(int irq, void *id);
+static void trng4xx_chk_overflow(void);
+
+int trng4xx_config_set(struct hal_config *cfg)
+{
+	struct device_node *rng_np = cfg->ofdev->node;
+	int rc = 0;
+
+	rc = of_address_to_resource(rng_np, 0, &trng4xx_dev.res);
+	if (rc)
+		return -ENODEV;
+
+	trng4xx_dev.csr    = ioremap(trng4xx_dev.res.start,
+				     trng4xx_dev.res.end -
+				trng4xx_dev.res.start + 1);
+	if (trng4xx_dev.csr == NULL) {
+		printk(KERN_ERR "unable to ioremap 0x%02X_%08X size %d\n",
+			(u32) (trng4xx_dev.res.start >> 32),
+			(u32) trng4xx_dev.res.start,
+			(u32) (trng4xx_dev.res.end -
+					trng4xx_dev.res.start + 1));
+		return -ENOMEM;
+	}
+
+	TRNG4XX_LOG("TRNG1 0x%02X_%08X size %d\n",
+			(u32) (trng4xx_dev.res.start >> 32),
+			(u32) trng4xx_dev.res.start,
+			(u32) (trng4xx_dev.res.end -
+					trng4xx_dev.res.start + 1));
+
+	trng4xx_dev.irq = of_irq_to_resource(rng_np, 0, NULL);
+
+        if (trng4xx_dev.irq == NO_IRQ) {
+		/* Un-map CSR */
+		iounmap(trng4xx_dev.csr);
+		trng4xx_dev.csr = NULL;
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+int trng4xx_pka_config_clear(void)
+{
+	iounmap(trng4xx_dev.csr);
+	return 0;
+}
+
+inline int trng4xx_hw_read32(u32 reg_addr, u32 *data_val)
+{
+	*data_val = in_be32((unsigned __iomem *)
+				(trng4xx_dev.csr + reg_addr));
+	return 0;
+}
+
+inline int trng4xx_hw_write32(u32 reg_addr, u32 data_val)
+{
+	out_be32((unsigned __iomem *) (trng4xx_dev.csr + reg_addr),
+		 data_val);
+        return 0;
+}
+
+int trng4xx_hw_init(void)
+{
+	int rc;
+
+	rc = request_irq(trng4xx_dev.irq, trng4xx_irq_handler,
+			 0, "TRNG", NULL);
+	if (rc != 0) {
+		printk(KERN_ERR "failed to register interrupt IRQ %d\n",
+			trng4xx_dev.irq);
+		return rc;
+	}
+	return 0;
+}
+
+int trng4xx_hw_deinit(void)
+{
+	free_irq(trng4xx_dev.irq, NULL);
+	return 0;
+}
+
+static irqreturn_t trng4xx_irq_handler(int irq, void *id)
+{
+	/* TRNG Alarm Counter overflow */
+	trng4xx_chk_overflow();
+	return IRQ_HANDLED;
+}
+
+/**
+ * TRNG Functions
+ *
+ */
+static void trng4xx_chk_overflow(void)
+{
+	/* TRNG Alarm Counter overflow */
+	int     rc;
+	u32    val;
+	struct trng4xx_cfg {
+		u32    ring1_delay_sel :3;
+		u32    ring2_delay_sel :3;
+		u32    reset_cnt       :6;
+	} __attribute__((packed));
+
+
+	rc = trng4xx_hw_write32(TRNG4XX_ALARMCNT_ADDR, val);
+	if (rc != 0)
+		return;
+
+	if (val > 128) {
+		struct trng4xx_cfg *trng4xx_cfg;
+
+		/* Alarm count is half, reset it */
+		rc = trng4xx_hw_read32(TRNG4XX_CFG_ADDR, &val);
+		if (rc != 0)
+			return;
+		trng4xx_cfg = (struct trng4xx_cfg *) &val;
+		++trng4xx_cfg->ring1_delay_sel;
+		trng4xx_cfg->ring2_delay_sel =
+				(~trng4xx_cfg->ring1_delay_sel) & 0x07;
+
+		rc = trng4xx_hw_write32(TRNG4XX_CFG_ADDR, val);
+		if (rc != 0)
+			return;
+		trng4xx_hw_write32(TRNG4XX_ALARMCNT_ADDR, 0x00000000);
+		if (rc != 0)
+			return;
+	}
+}
+
+#define MAX_TRY     3
+int	trng4xx_random(u32 *rand_val)
+{
+	u32	val = 0;
+	int	rc;
+	u16     try_cnt = 0;
+	
+	down(&trng4xx_dev.access_prot);
+	do {
+		rc = trng4xx_hw_read32(TRNG4XX_STATUS_ADDR, &val);
+		if (rc != 0)
+			goto err;
+	} while ((val & TRNG4XX_STATUS_BUSY) && ++try_cnt <= MAX_TRY);
+	if (val & TRNG4XX_STATUS_BUSY) {
+		rc = -EINPROGRESS;
+		goto err;
+	}
+	rc = trng4xx_hw_read32(TRNG4XX_OUTPUT_ADDR, rand_val);
+
+err:
+	up(&trng4xx_dev.access_prot);
+	return rc;
+}
+EXPORT_SYMBOL_GPL(trng4xx_random);
+
+static int trng4xx_data_present(struct hwrng *rng, int wait)
+{
+	struct trng4xx_dev *dev = (struct trng4xx_dev *) rng->priv;
+	int     i;
+	u32 	val;
+
+	down(&trng4xx_dev.access_prot);
+	for (i = 0; i < 20; i++) {
+		udelay(10);
+		trng4xx_hw_read32(TRNG4XX_STATUS_ADDR, &val);
+		if (!(val & TRNG4XX_STATUS_BUSY)) {
+			trng4xx_hw_read32(TRNG4XX_OUTPUT_ADDR, &dev->datum);
+			break;
+		}
+		if (!wait)
+			break;
+	}
+	up(&trng4xx_dev.access_prot);
+	return (val & TRNG4XX_STATUS_BUSY) ? 0 : 1;
+}
+
+static int trng4xx_data_read(struct hwrng *rng, u32 *data)
+{
+	struct trng4xx_dev *dev = (struct trng4xx_dev *) rng->priv;
+
+	*data = dev->datum;
+	//printk("*data = 0x%08x\n", *data);
+	return 4;
+}
+
+static int trng4xx_init(struct hwrng *rng)
+{
+	return trng4xx_hw_init();
+}
+
+static void trng4xx_cleanup(struct hwrng *rng)
+{
+	trng4xx_hw_deinit();
+}
+
+static struct hwrng trng4xx_func = {
+	.name		= "ppc4xx-trng",
+	.init		= trng4xx_init,
+	.cleanup	= trng4xx_cleanup,
+	.data_present	= trng4xx_data_present,
+	.data_read	= trng4xx_data_read,
+	.priv		= (unsigned long) &trng4xx_dev,
+};
+
+/**
+ * Setup Driver with platform registration
+ *
+ */
+static int __devinit trng4xx_probe(struct of_device *ofdev,
+				     const struct of_device_id *match)
+{
+	struct hal_config hw_cfg;
+	int 	rc;
+
+	hw_cfg.ofdev = ofdev;
+	rc = trng4xx_config_set(&hw_cfg);
+	if (rc != 0)
+		return rc;
+
+	TRNG4XX_LOG("AMCC 4xx TRNG v%s @0x%02X_%08X size %d IRQ %d\n",
+		TRNG4XX_VER_STR,
+		(u32) (trng4xx_dev.res.start >> 32),
+		(u32) trng4xx_dev.res.start,
+		(u32) (trng4xx_dev.res.end - trng4xx_dev.res.start + 1),
+		trng4xx_dev.irq);
+
+	init_MUTEX(&trng4xx_dev.access_prot);
+
+	rc = hwrng_register(&trng4xx_func);
+	if (rc) {
+		printk(KERN_ERR
+			"AMCC 4xx TRNG registering failed error %d\n", rc);
+		goto err;
+	}
+
+	return rc;
+
+err:
+	trng4xx_pka_config_clear();
+	return rc;
+}
+
+static int __devexit trng4xx_remove(struct of_device *dev)
+{
+	hwrng_unregister(&trng4xx_func);
+	trng4xx_pka_config_clear();
+	return 0;
+}
+
+static struct of_device_id trng4xx_match[] = {
+	{ .compatible      = "ppc4xx-trng", },
+	{ .compatible      = "amcc,ppc4xx-trng", },
+	{ },
+};
+
+static struct of_platform_driver trng4xx_driver = {
+	.name		= "ppc4xx-trng",
+	.match_table	= trng4xx_match,
+	.probe		= trng4xx_probe,
+	.remove		= trng4xx_remove,
+};
+
+static int __init mod_init(void)
+{
+  return of_register_platform_driver(&trng4xx_driver);
+}
+
+static void __exit mod_exit(void)
+{
+	of_unregister_platform_driver(&trng4xx_driver);
+}
+
+module_init(mod_init);
+module_exit(mod_exit);
+
+MODULE_DESCRIPTION("AMCC 4xx True Random Number Generator");
+MODULE_LICENSE("GPL");