pasemi: hardware rng driver
Driver for the on-chip hardware random number generator on PA Semi
PA6T-1682M.
Signed-off-by: Egor Martovetsky <egor@pasemi.com>
Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Michael Buesch <mb@bu3sch.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Kumar Gala <galak@gate.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig
index 5f3acd8..7cda04b 100644
--- a/drivers/char/hw_random/Kconfig
+++ b/drivers/char/hw_random/Kconfig
@@ -91,3 +91,17 @@
module will be called omap-rng.
If unsure, say Y.
+
+config HW_RANDOM_PASEMI
+ tristate "PA Semi HW Random Number Generator support"
+ depends on HW_RANDOM && PPC_PASEMI
+ default HW_RANDOM
+ ---help---
+ This driver provides kernel-side support for the Random Number
+ Generator hardware found on PA6T-1682M processor.
+
+ To compile this driver as a module, choose M here: the
+ module will be called pasemi-rng.
+
+ If unsure, say Y.
+
diff --git a/drivers/char/hw_random/Makefile b/drivers/char/hw_random/Makefile
index c41fa19..c8b7300 100644
--- a/drivers/char/hw_random/Makefile
+++ b/drivers/char/hw_random/Makefile
@@ -10,3 +10,4 @@
obj-$(CONFIG_HW_RANDOM_VIA) += via-rng.o
obj-$(CONFIG_HW_RANDOM_IXP4XX) += ixp4xx-rng.o
obj-$(CONFIG_HW_RANDOM_OMAP) += omap-rng.o
+obj-$(CONFIG_HW_RANDOM_PASEMI) += pasemi-rng.o
diff --git a/drivers/char/hw_random/pasemi-rng.c b/drivers/char/hw_random/pasemi-rng.c
new file mode 100644
index 0000000..fa6040b
--- /dev/null
+++ b/drivers/char/hw_random/pasemi-rng.c
@@ -0,0 +1,156 @@
+/*
+ * Copyright (C) 2006-2007 PA Semi, Inc
+ *
+ * Maintained by: Olof Johansson <olof@lixom.net>
+ *
+ * Driver for the PWRficient onchip rng
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/hw_random.h>
+#include <asm/of_platform.h>
+#include <asm/io.h>
+
+#define SDCRNG_CTL_REG 0x00
+#define SDCRNG_CTL_FVLD_M 0x0000f000
+#define SDCRNG_CTL_FVLD_S 12
+#define SDCRNG_CTL_KSZ 0x00000800
+#define SDCRNG_CTL_RSRC_CRG 0x00000010
+#define SDCRNG_CTL_RSRC_RRG 0x00000000
+#define SDCRNG_CTL_CE 0x00000004
+#define SDCRNG_CTL_RE 0x00000002
+#define SDCRNG_CTL_DR 0x00000001
+#define SDCRNG_CTL_SELECT_RRG_RNG (SDCRNG_CTL_RE | SDCRNG_CTL_RSRC_RRG)
+#define SDCRNG_CTL_SELECT_CRG_RNG (SDCRNG_CTL_CE | SDCRNG_CTL_RSRC_CRG)
+#define SDCRNG_VAL_REG 0x20
+
+#define MODULE_NAME "pasemi_rng"
+
+static int pasemi_rng_data_present(struct hwrng *rng)
+{
+ void __iomem *rng_regs = (void __iomem *)rng->priv;
+
+ return (in_le32(rng_regs + SDCRNG_CTL_REG)
+ & SDCRNG_CTL_FVLD_M) ? 1 : 0;
+}
+
+static int pasemi_rng_data_read(struct hwrng *rng, u32 *data)
+{
+ void __iomem *rng_regs = (void __iomem *)rng->priv;
+ *data = in_le32(rng_regs + SDCRNG_VAL_REG);
+ return 4;
+}
+
+static int pasemi_rng_init(struct hwrng *rng)
+{
+ void __iomem *rng_regs = (void __iomem *)rng->priv;
+ u32 ctl;
+
+ ctl = SDCRNG_CTL_DR | SDCRNG_CTL_SELECT_RRG_RNG | SDCRNG_CTL_KSZ;
+ out_le32(rng_regs + SDCRNG_CTL_REG, ctl);
+ out_le32(rng_regs + SDCRNG_CTL_REG, ctl & ~SDCRNG_CTL_DR);
+
+ return 0;
+}
+
+static void pasemi_rng_cleanup(struct hwrng *rng)
+{
+ void __iomem *rng_regs = (void __iomem *)rng->priv;
+ u32 ctl;
+
+ ctl = SDCRNG_CTL_RE | SDCRNG_CTL_CE;
+ out_le32(rng_regs + SDCRNG_CTL_REG,
+ in_le32(rng_regs + SDCRNG_CTL_REG) & ~ctl);
+}
+
+static struct hwrng pasemi_rng = {
+ .name = MODULE_NAME,
+ .init = pasemi_rng_init,
+ .cleanup = pasemi_rng_cleanup,
+ .data_present = pasemi_rng_data_present,
+ .data_read = pasemi_rng_data_read,
+};
+
+static int __devinit rng_probe(struct of_device *ofdev,
+ const struct of_device_id *match)
+{
+ void __iomem *rng_regs;
+ struct device_node *rng_np = ofdev->node;
+ struct resource res;
+ int err = 0;
+
+ err = of_address_to_resource(rng_np, 0, &res);
+ if (err)
+ return -ENODEV;
+
+ rng_regs = ioremap(res.start, 0x100);
+
+ if (!rng_regs)
+ return -ENOMEM;
+
+ pasemi_rng.priv = (unsigned long)rng_regs;
+
+ printk(KERN_INFO "Registering PA Semi RNG\n");
+
+ err = hwrng_register(&pasemi_rng);
+
+ if (err)
+ iounmap(rng_regs);
+
+ return err;
+}
+
+static int __devexit rng_remove(struct of_device *dev)
+{
+ void __iomem *rng_regs = (void __iomem *)pasemi_rng.priv;
+
+ hwrng_unregister(&pasemi_rng);
+ iounmap(rng_regs);
+
+ return 0;
+}
+
+static struct of_device_id rng_match[] = {
+ {
+ .compatible = "1682m-rng",
+ },
+ {},
+};
+
+static struct of_platform_driver rng_driver = {
+ .name = "pasemi-rng",
+ .match_table = rng_match,
+ .probe = rng_probe,
+ .remove = rng_remove,
+};
+
+static int __init rng_init(void)
+{
+ return of_register_platform_driver(&rng_driver);
+}
+module_init(rng_init);
+
+static void __exit rng_exit(void)
+{
+ of_unregister_platform_driver(&rng_driver);
+}
+module_exit(rng_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Egor Martovetsky <egor@pasemi.com>");
+MODULE_DESCRIPTION("H/W RNG driver for PA Semi processor");