[PATCH] [2.6.22] pasemi: hardware rng driver

[PATCH] [2.6.22] pasemi: hardware rng driver

[Olof Johansson]

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>


Index: powerpc/drivers/char/hw_random/Kconfig
===================================================================
--- powerpc.orig/drivers/char/hw_random/Kconfig
+++ powerpc/drivers/char/hw_random/Kconfig
@@ -91,3 +91,17 @@ config HW_RANDOM_OMAP
 	  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.
+
Index: powerpc/drivers/char/hw_random/Makefile
===================================================================
--- powerpc.orig/drivers/char/hw_random/Makefile
+++ powerpc/drivers/char/hw_random/Makefile
@@ -10,3 +10,4 @@ obj-$(CONFIG_HW_RANDOM_GEODE) += geode-r
 obj-$(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
Index: powerpc/drivers/char/hw_random/pasemi-rng.c
===================================================================
--- /dev/null
+++ powerpc/drivers/char/hw_random/pasemi-rng.c
@@ -0,0 +1,152 @@
+/*
+ * 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 void __iomem *rng_regs;
+
+static int pasemi_rng_data_present(struct hwrng *rng)
+{
+	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)
+{
+	*data = in_le32(rng_regs + SDCRNG_VAL_REG);
+	return 4;
+}
+
+static int pasemi_rng_init(struct hwrng *rng)
+{
+	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)
+{
+	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)
+{
+	struct device_node *rng_np;
+	struct resource res;
+	int err = 0;
+
+	rng_np = of_find_compatible_node(NULL, "rng", "1682m-rng");
+	if (!rng_np)
+		return -ENODEV;
+
+	err = of_address_to_resource(rng_np, 0, &res);
+	of_node_put(rng_np);
+
+	if (err)
+		return -EINVAL;
+
+	if (!rng_regs)
+		rng_regs = ioremap(res.start, 0x100);
+
+	if (!rng_regs)
+		return -EPERM;
+
+	printk(KERN_INFO "Registering PA Semi RNG\n");
+
+	return hwrng_register(&pasemi_rng);
+}
+
+static int rng_remove(struct of_device *dev)
+{
+	iounmap(rng_regs);
+	hwrng_unregister(&pasemi_rng);
+
+	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,
+};
+
+int rng_init(void)
+{
+	return of_register_platform_driver(&rng_driver);
+}
+
+void rng_exit(void)
+{
+	of_unregister_platform_driver(&rng_driver);
+}
+
+device_initcall(rng_init);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Egor Martovetsky <egor@pasemi.com>");
+MODULE_DESCRIPTION("H/W RNG driver for PA Semi processor");

Re: [PATCH] [2.6.22] pasemi: hardware rng driver

[Arnd Bergmann]

On Wednesday 25 April 2007, Olof Johansson wrote:

> +static void __iomem *rng_regs;
> +
> +static int pasemi_rng_data_present(struct hwrng *rng)
> +{
> +	return (in_le32(rng_regs + SDCRNG_CTL_REG)
> +		& SDCRNG_CTL_FVLD_M) ? 1 : 0;
> +}

It would be nicer to get rid of the global rng_regs variable by sticking
it into rng->priv.

> +static int __devinit rng_probe(struct of_device *ofdev,
> +				     const struct of_device_id *match)
> +{
> +	struct device_node *rng_np;
> +	struct resource res;
> +	int err = 0;
> +
> +	rng_np = of_find_compatible_node(NULL, "rng", "1682m-rng");
> +	if (!rng_np)
> +		return -ENODEV;

I would guess that the call to of_find_compatible_node is entirely bogus
here, because the device is already passed in as ofdev in to the probe
function.

> +int rng_init(void)
> +{
> +       return of_register_platform_driver(&rng_driver);
> +}
> +
> +void rng_exit(void)
> +{
> +       of_unregister_platform_driver(&rng_driver);
> +}
> +
> +device_initcall(rng_init);

rng_init and rng_exit should be static
rng_init should be __init
rng_exit should be __exit
Since the driver is tristate in Kconfig, it would be more conventional to
use module_init() instead of device_initcall().
rng_exit needs to be marked as module_exit() to allow unloading the driver.

	Arnd <><

Re: [PATCH] [2.6.22] pasemi: hardware rng driver

[Olof Johansson]

On Thu, Apr 26, 2007 at 01:38:31AM +0200, Arnd Bergmann wrote:
> On Wednesday 25 April 2007, Olof Johansson wrote:
> 
> > +static void __iomem *rng_regs;
> > +
> > +static int pasemi_rng_data_present(struct hwrng *rng)
> > +{
> > +	return (in_le32(rng_regs + SDCRNG_CTL_REG)
> > +		& SDCRNG_CTL_FVLD_M) ? 1 : 0;
> > +}
> 
> It would be nicer to get rid of the global rng_regs variable by sticking
> it into rng->priv.

Good point.

> > +static int __devinit rng_probe(struct of_device *ofdev,
> > +				     const struct of_device_id *match)
> > +{
> > +	struct device_node *rng_np;
> > +	struct resource res;
> > +	int err = 0;
> > +
> > +	rng_np = of_find_compatible_node(NULL, "rng", "1682m-rng");
> > +	if (!rng_np)
> > +		return -ENODEV;
> 
> I would guess that the call to of_find_compatible_node is entirely bogus
> here, because the device is already passed in as ofdev in to the probe
> function.

Yup. Leftover from pre-of_platform

> > +int rng_init(void)
> > +{
> > +       return of_register_platform_driver(&rng_driver);
> > +}
> > +
> > +void rng_exit(void)
> > +{
> > +       of_unregister_platform_driver(&rng_driver);
> > +}
> > +
> > +device_initcall(rng_init);
> 
> rng_init and rng_exit should be static
> rng_init should be __init
> rng_exit should be __exit
> Since the driver is tristate in Kconfig, it would be more conventional to
> use module_init() instead of device_initcall().
> rng_exit needs to be marked as module_exit() to allow unloading the driver.

Yup, will fix.


Thanks.


-Olof

[PATCH v2] [2.6.22] pasemi: hardware rng driver

[Olof Johansson]

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>

---

Changes since last version:
* Moved register pointer to hwrng->priv
* Cleanups (__init/__exit, module_init/exit)

Index: powerpc/drivers/char/hw_random/Kconfig
===================================================================
--- powerpc.orig/drivers/char/hw_random/Kconfig
+++ powerpc/drivers/char/hw_random/Kconfig
@@ -91,3 +91,17 @@ config HW_RANDOM_OMAP
 	  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.
+
Index: powerpc/drivers/char/hw_random/Makefile
===================================================================
--- powerpc.orig/drivers/char/hw_random/Makefile
+++ powerpc/drivers/char/hw_random/Makefile
@@ -10,3 +10,4 @@ obj-$(CONFIG_HW_RANDOM_GEODE) += geode-r
 obj-$(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
Index: powerpc/drivers/char/hw_random/pasemi-rng.c
===================================================================
--- /dev/null
+++ powerpc/drivers/char/hw_random/pasemi-rng.c
@@ -0,0 +1,150 @@
+/*
+ * 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)
+{
+	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 -EINVAL;
+
+	pasemi_rng.priv = (unsigned long)ioremap(res.start, 0x100);
+
+	if (pasemi_rng.priv == 0)
+		return -EPERM;
+
+	printk(KERN_INFO "Registering PA Semi RNG\n");
+
+	return hwrng_register(&pasemi_rng);
+}
+
+static int __devexit rng_remove(struct of_device *dev)
+{
+	void __iomem *rng_regs = (void __iomem *)pasemi_rng.priv;
+
+	iounmap(rng_regs);
+	hwrng_unregister(&pasemi_rng);
+
+	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");

Re: [PATCH v2] [2.6.22] pasemi: hardware rng driver

[Arnd Bergmann]

On Thursday 26 April 2007, Olof Johansson wrote:
> 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>

Acked-by: Arnd Bergmann <arnd@arndb.de>

Re: [PATCH] [2.6.22] pasemi: hardware rng driver

[Michael Buesch]

On Wednesday 25 April 2007 22:45:12 Olof Johansson wrote:
> +static int __devinit rng_probe(struct of_device *ofdev,
> +				     const struct of_device_id *match)
> +{
> +	struct device_node *rng_np;
> +	struct resource res;
> +	int err = 0;
> +
> +	rng_np = of_find_compatible_node(NULL, "rng", "1682m-rng");
> +	if (!rng_np)
> +		return -ENODEV;
> +
> +	err = of_address_to_resource(rng_np, 0, &res);
> +	of_node_put(rng_np);
> +
> +	if (err)
> +		return -EINVAL;

I think EINVAL is not the correct error code. I'd suggest ENODEV.

> +	if (!rng_regs)
> +		rng_regs = ioremap(res.start, 0x100);
> +
> +	if (!rng_regs)
> +		return -EPERM;

I think EPERM is not the correct error code. I'd suggest ENOMEM.

> +	printk(KERN_INFO "Registering PA Semi RNG\n");
> +
> +	return hwrng_register(&pasemi_rng);

Resource leak.
Please do something like

	err = hwrng_register(&pasemi_rng);
	if (err)
		iounmap(rng_regs);
	return err;

> +}
> +
> +static int rng_remove(struct of_device *dev)
> +{
> +	iounmap(rng_regs);
> +	hwrng_unregister(&pasemi_rng);

Swap these to prevent race conditions.

> +
> +	return 0;
> +}



-- 
Greetings Michael.

Re: [PATCH] [2.6.22] pasemi: hardware rng driver

[Michael Buesch]

On Thursday 26 April 2007 01:38:31 Arnd Bergmann wrote:
> On Wednesday 25 April 2007, Olof Johansson wrote:
> 
> > +static void __iomem *rng_regs;
> > +
> > +static int pasemi_rng_data_present(struct hwrng *rng)
> > +{
> > +	return (in_le32(rng_regs + SDCRNG_CTL_REG)
> > +		& SDCRNG_CTL_FVLD_M) ? 1 : 0;
> > +}
> 
> It would be nicer to get rid of the global rng_regs variable by sticking
> it into rng->priv.

Yeah, I think that would be better. Saves one global variable.


-- 
Greetings Michael.

Re: [PATCH] [2.6.22] pasemi: hardware rng driver

[Olof Johansson]

Hi Michael,

All good points, fixed in v3 (posted shortly).


Thanks,

-Olof

On Thu, Apr 26, 2007 at 11:22:03AM +0200, Michael Buesch wrote:
> On Wednesday 25 April 2007 22:45:12 Olof Johansson wrote:
> > +static int __devinit rng_probe(struct of_device *ofdev,
> > +				     const struct of_device_id *match)
> > +{
> > +	struct device_node *rng_np;
> > +	struct resource res;
> > +	int err = 0;
> > +
> > +	rng_np = of_find_compatible_node(NULL, "rng", "1682m-rng");
> > +	if (!rng_np)
> > +		return -ENODEV;
> > +
> > +	err = of_address_to_resource(rng_np, 0, &res);
> > +	of_node_put(rng_np);
> > +
> > +	if (err)
> > +		return -EINVAL;
> 
> I think EINVAL is not the correct error code. I'd suggest ENODEV.
> 
> > +	if (!rng_regs)
> > +		rng_regs = ioremap(res.start, 0x100);
> > +
> > +	if (!rng_regs)
> > +		return -EPERM;
> 
> I think EPERM is not the correct error code. I'd suggest ENOMEM.
> 
> > +	printk(KERN_INFO "Registering PA Semi RNG\n");
> > +
> > +	return hwrng_register(&pasemi_rng);
> 
> Resource leak.
> Please do something like
> 
> 	err = hwrng_register(&pasemi_rng);
> 	if (err)
> 		iounmap(rng_regs);
> 	return err;
> 
> > +}
> > +
> > +static int rng_remove(struct of_device *dev)
> > +{
> > +	iounmap(rng_regs);
> > +	hwrng_unregister(&pasemi_rng);
> 
> Swap these to prevent race conditions.
> 
> > +
> > +	return 0;
> > +}
> 
> 
> 
> -- 
> Greetings Michael.

[PATCH v3] [2.6.22] pasemi: hardware rng driver

[Olof Johansson]

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>


---

v3:
* error return codes
* iounmap on register fail
* fix iounmap race on remove

v2:
* Moved register pointer to hwrng->priv
* Cleanups (__init/__exit, module_init/exit)

Index: powerpc/drivers/char/hw_random/Kconfig
===================================================================
--- powerpc.orig/drivers/char/hw_random/Kconfig
+++ powerpc/drivers/char/hw_random/Kconfig
@@ -91,3 +91,17 @@ config HW_RANDOM_OMAP
 	  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.
+
Index: powerpc/drivers/char/hw_random/Makefile
===================================================================
--- powerpc.orig/drivers/char/hw_random/Makefile
+++ powerpc/drivers/char/hw_random/Makefile
@@ -10,3 +10,4 @@ obj-$(CONFIG_HW_RANDOM_GEODE) += geode-r
 obj-$(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
Index: powerpc/drivers/char/hw_random/pasemi-rng.c
===================================================================
--- /dev/null
+++ powerpc/drivers/char/hw_random/pasemi-rng.c
@@ -0,0 +1,158 @@
+/*
+ * 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");

[PATCH 2.6.22] pasemi: hardware rng driver

[Michael Buesch]

From: Olof Johansson <olof@lixom.net>

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>


---

This is patch version 3.

v3:
* error return codes
* iounmap on register fail
* fix iounmap race on remove

v2:
* Moved register pointer to hwrng->priv
* Cleanups (__init/__exit, module_init/exit)

Index: powerpc/drivers/char/hw_random/Kconfig
===================================================================
--- powerpc.orig/drivers/char/hw_random/Kconfig
+++ powerpc/drivers/char/hw_random/Kconfig
@@ -91,3 +91,17 @@ config HW_RANDOM_OMAP
 	  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.
+
Index: powerpc/drivers/char/hw_random/Makefile
===================================================================
--- powerpc.orig/drivers/char/hw_random/Makefile
+++ powerpc/drivers/char/hw_random/Makefile
@@ -10,3 +10,4 @@ obj-$(CONFIG_HW_RANDOM_GEODE) += geode-r
 obj-$(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
Index: powerpc/drivers/char/hw_random/pasemi-rng.c
===================================================================
--- /dev/null
+++ powerpc/drivers/char/hw_random/pasemi-rng.c
@@ -0,0 +1,158 @@
+/*
+ * 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");


-- 
Greetings Michael.