crypto4xx: integrate ppc4xx-rng into crypto4xx

This patch integrates the ppc4xx-rng driver into the existing
crypto4xx. This is because the true random number generator
is controlled and part of the security core.

Signed-off-by: Christian Lamparter <chunkeey@googlemail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/char/hw_random/Kconfig

@@ -268,19 +268,6 @@ config HW_RANDOM_NOMADIK
 
 	  If unsure, say Y.
 
-config HW_RANDOM_PPC4XX
-	tristate "PowerPC 4xx generic true random number generator support"
-	depends on PPC && 4xx
-	default HW_RANDOM
-	---help---
-	 This driver provides the kernel-side support for the TRNG hardware
-	 found in the security function of some PowerPC 4xx SoCs.
-
-	 To compile this driver as a module, choose M here: the
-	 module will be called ppc4xx-rng.
-
-	 If unsure, say N.
-
 config HW_RANDOM_PSERIES
 	tristate "pSeries HW Random Number Generator support"
 	depends on PPC64 && IBMVIO

drivers/char/hw_random/Makefile

@@ -22,7 +22,6 @@ obj-$(CONFIG_HW_RANDOM_TX4939) += tx4939-rng.o
 obj-$(CONFIG_HW_RANDOM_MXC_RNGA) += mxc-rnga.o
 obj-$(CONFIG_HW_RANDOM_OCTEON) += octeon-rng.o
 obj-$(CONFIG_HW_RANDOM_NOMADIK) += nomadik-rng.o
-obj-$(CONFIG_HW_RANDOM_PPC4XX) += ppc4xx-rng.o
 obj-$(CONFIG_HW_RANDOM_PSERIES) += pseries-rng.o
 obj-$(CONFIG_HW_RANDOM_POWERNV) += powernv-rng.o
 obj-$(CONFIG_HW_RANDOM_EXYNOS)	+= exynos-rng.o

drivers/crypto/Kconfig

@@ -279,6 +279,14 @@ config CRYPTO_DEV_PPC4XX
 	help
 	  This option allows you to have support for AMCC crypto acceleration.
 
+config HW_RANDOM_PPC4XX
+	bool "PowerPC 4xx generic true random number generator support"
+	depends on CRYPTO_DEV_PPC4XX && HW_RANDOM
+	default y
+	---help---
+	 This option provides the kernel-side support for the TRNG hardware
+	 found in the security function of some PowerPC 4xx SoCs.
+
 config CRYPTO_DEV_OMAP_SHAM
 	tristate "Support for OMAP MD5/SHA1/SHA2 hw accelerator"
 	depends on ARCH_OMAP2PLUS

drivers/crypto/amcc/Makefile

@@ -1,2 +1,3 @@
 obj-$(CONFIG_CRYPTO_DEV_PPC4XX) += crypto4xx.o
 crypto4xx-y :=  crypto4xx_core.o crypto4xx_alg.o crypto4xx_sa.o
+crypto4xx-$(CONFIG_HW_RANDOM_PPC4XX) += crypto4xx_trng.o

drivers/crypto/amcc/crypto4xx_core.c

@@ -40,6 +40,7 @@
 #include "crypto4xx_reg_def.h"
 #include "crypto4xx_core.h"
 #include "crypto4xx_sa.h"
+#include "crypto4xx_trng.h"
 
 #define PPC4XX_SEC_VERSION_STR			"0.5"
 
@@ -1225,6 +1226,7 @@ static int crypto4xx_probe(struct platform_device *ofdev)
 	if (rc)
 		goto err_start_dev;
 
+	ppc4xx_trng_probe(core_dev);
 	return 0;
 
 err_start_dev:
@@ -1252,6 +1254,8 @@ static int crypto4xx_remove(struct platform_device *ofdev)
 	struct device *dev = &ofdev->dev;
 	struct crypto4xx_core_device *core_dev = dev_get_drvdata(dev);
 
+	ppc4xx_trng_remove(core_dev);
+
 	free_irq(core_dev->irq, dev);
 	irq_dispose_mapping(core_dev->irq);
 
@@ -1272,7 +1276,7 @@ MODULE_DEVICE_TABLE(of, crypto4xx_match);
 
 static struct platform_driver crypto4xx_driver = {
 	.driver = {
-		.name = "crypto4xx",
+		.name = MODULE_NAME,
 		.of_match_table = crypto4xx_match,
 	},
 	.probe		= crypto4xx_probe,
@@ -1284,4 +1288,3 @@ module_platform_driver(crypto4xx_driver);
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("James Hsiao <jhsiao@amcc.com>");
 MODULE_DESCRIPTION("Driver for AMCC PPC4xx crypto accelerator");
-

drivers/crypto/amcc/crypto4xx_core.h

@@ -24,6 +24,8 @@
 
 #include <crypto/internal/hash.h>
 
+#define MODULE_NAME "crypto4xx"
+
 #define PPC460SX_SDR0_SRST                      0x201
 #define PPC405EX_SDR0_SRST                      0x200
 #define PPC460EX_SDR0_SRST                      0x201
@@ -72,6 +74,7 @@ struct crypto4xx_device {
 	char *name;
 	u64  ce_phy_address;
 	void __iomem *ce_base;
+	void __iomem *trng_base;
 
 	void *pdr;			/* base address of packet
 					descriptor ring */
@@ -106,6 +109,7 @@ struct crypto4xx_core_device {
 	struct device *device;
 	struct platform_device *ofdev;
 	struct crypto4xx_device *dev;
+	struct hwrng *trng;
 	u32 int_status;
 	u32 irq;
 	struct tasklet_struct tasklet;

drivers/crypto/amcc/crypto4xx_reg_def.h

@@ -125,6 +125,7 @@
 #define PPC4XX_INTERRUPT_CLR			0x3ffff
 #define PPC4XX_PRNG_CTRL_AUTO_EN		0x3
 #define PPC4XX_DC_3DES_EN			1
+#define PPC4XX_TRNG_EN				0x00020000
 #define PPC4XX_INT_DESCR_CNT			4
 #define PPC4XX_INT_TIMEOUT_CNT			0
 #define PPC4XX_INT_CFG				1

drivers/crypto/amcc/crypto4xx_trng.c

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