[PATCH 1/5] hw_random: ixp4xx: enable compile-testing

[PATCH 1/5] hw_random: ixp4xx: enable compile-testing

[Linus Walleij]

From: Arnd Bergmann <arnd@arndb.de>

The driver is almost portable already, it just needs to
include the new header for the cpu definition.

Cc: Deepak Saxena <dsaxena@plexity.net>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
The idea is to apply this through the ARM SoC tree along
with other IXP4xx refactorings.
Please tell me if you prefer another solution.
---
 drivers/char/hw_random/Kconfig      | 2 +-
 drivers/char/hw_random/ixp4xx-rng.c | 3 +--
 2 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig
index 1fe006f3f12f..f033a11cc90d 100644
--- a/drivers/char/hw_random/Kconfig
+++ b/drivers/char/hw_random/Kconfig
@@ -152,7 +152,7 @@ config HW_RANDOM_VIA
 
 config HW_RANDOM_IXP4XX
 	tristate "Intel IXP4xx NPU HW Pseudo-Random Number Generator support"
-	depends on ARCH_IXP4XX
+	depends on ARCH_IXP4XX || COMPILE_TEST
 	default HW_RANDOM
 	help
 	  This driver provides kernel-side support for the Pseudo-Random
diff --git a/drivers/char/hw_random/ixp4xx-rng.c b/drivers/char/hw_random/ixp4xx-rng.c
index beec1627db3c..34781028caec 100644
--- a/drivers/char/hw_random/ixp4xx-rng.c
+++ b/drivers/char/hw_random/ixp4xx-rng.c
@@ -21,10 +21,9 @@
 #include <linux/init.h>
 #include <linux/bitops.h>
 #include <linux/hw_random.h>
+#include <linux/soc/ixp4xx/cpu.h>
 
 #include <asm/io.h>
-#include <mach/hardware.h>
-
 
 static int ixp4xx_rng_data_read(struct hwrng *rng, u32 *buffer)
 {
-- 
2.30.2

[PATCH 2/5] hw_random: ixp4xx: Use SPDX license tag

[Linus Walleij]

This switches the IXP4xx hardware random driver to use
the SPDX type license tag.

Cc: Deepak Saxena <dsaxena@plexity.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
The idea is to apply this through the ARM SoC tree along
with other IXP4xx refactorings.
Please tell me if you prefer another solution.
---
 drivers/char/hw_random/ixp4xx-rng.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/drivers/char/hw_random/ixp4xx-rng.c b/drivers/char/hw_random/ixp4xx-rng.c
index 34781028caec..defd8176cb68 100644
--- a/drivers/char/hw_random/ixp4xx-rng.c
+++ b/drivers/char/hw_random/ixp4xx-rng.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * drivers/char/hw_random/ixp4xx-rng.c
  *
@@ -8,10 +9,6 @@
  * Copyright 2005 (c) MontaVista Software, Inc.
  *
  * Fixes by Michael Buesch
- *
- * This file is licensed under  the terms of the GNU General Public
- * License version 2. This program is licensed "as is" without any
- * warranty of any kind, whether express or implied.
  */
 
 #include <linux/kernel.h>
-- 
2.30.2

Re: [PATCH 2/5] hw_random: ixp4xx: Use SPDX license tag

[Herbert Xu]

On Tue, May 11, 2021 at 03:29:25PM +0200, Linus Walleij wrote:
> This switches the IXP4xx hardware random driver to use
> the SPDX type license tag.
> 
> Cc: Deepak Saxena <dsaxena@plexity.net>
> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
> ---
> The idea is to apply this through the ARM SoC tree along
> with other IXP4xx refactorings.
> Please tell me if you prefer another solution.
> ---
>  drivers/char/hw_random/ixp4xx-rng.c | 5 +----
>  1 file changed, 1 insertion(+), 4 deletions(-)

Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt

[PATCH 3/5] hw_random: ixp4xx: Turn into a module

[Linus Walleij]

Instead of just initializing always, which will invariably
create problems on multiplatform builds, turn this driver into
a module and pass a resource with the memory location.
The device only exist on the IXP46x so we only register
the device for the IXP46x SoC.

Cc: Deepak Saxena <dsaxena@plexity.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
The idea is to apply this through the ARM SoC tree along
with other IXP4xx refactorings.
Please tell me if you prefer another solution.
---
 arch/arm/mach-ixp4xx/common.c       | 24 ++++++++++++++++++-
 drivers/char/hw_random/ixp4xx-rng.c | 37 +++++++++++++----------------
 2 files changed, 40 insertions(+), 21 deletions(-)

diff --git a/arch/arm/mach-ixp4xx/common.c b/arch/arm/mach-ixp4xx/common.c
index f86c1bf34eea..a10aa14d09b1 100644
--- a/arch/arm/mach-ixp4xx/common.c
+++ b/arch/arm/mach-ixp4xx/common.c
@@ -237,6 +237,27 @@ static struct resource ixp46x_i2c_resources[] = {
 	}
 };
 
+/* A single 32-bit register on IXP46x */
+#define IXP4XX_HWRANDOM_BASE_PHYS	0x70002100
+
+static struct resource ixp46x_hwrandom_resource[] = {
+	{
+		.start = IXP4XX_HWRANDOM_BASE_PHYS,
+		.end = IXP4XX_HWRANDOM_BASE_PHYS + 0x3,
+		.flags = IORESOURCE_MEM,
+	},
+};
+
+static struct platform_device ixp46x_hwrandom_device = {
+	.name           = "ixp4xx-hwrandom",
+	.id             = -1,
+	.dev = {
+		.coherent_dma_mask      = DMA_BIT_MASK(32),
+	},
+	.resource = ixp46x_hwrandom_resource,
+	.num_resources  = ARRAY_SIZE(ixp46x_hwrandom_resource),
+};
+
 /*
  * I2C controller. The IXP46x uses the same block as the IOP3xx, so
  * we just use the same device name.
@@ -249,7 +270,8 @@ static struct platform_device ixp46x_i2c_controller = {
 };
 
 static struct platform_device *ixp46x_devices[] __initdata = {
-	&ixp46x_i2c_controller
+	&ixp46x_hwrandom_device,
+	&ixp46x_i2c_controller,
 };
 
 unsigned long ixp4xx_exp_bus_size;
diff --git a/drivers/char/hw_random/ixp4xx-rng.c b/drivers/char/hw_random/ixp4xx-rng.c
index defd8176cb68..8b59aeefd4a4 100644
--- a/drivers/char/hw_random/ixp4xx-rng.c
+++ b/drivers/char/hw_random/ixp4xx-rng.c
@@ -15,6 +15,7 @@
 #include <linux/types.h>
 #include <linux/module.h>
 #include <linux/moduleparam.h>
+#include <linux/platform_device.h>
 #include <linux/init.h>
 #include <linux/bitops.h>
 #include <linux/hw_random.h>
@@ -36,35 +37,31 @@ static struct hwrng ixp4xx_rng_ops = {
 	.data_read	= ixp4xx_rng_data_read,
 };
 
-static int __init ixp4xx_rng_init(void)
+static int ixp4xx_rng_probe(struct platform_device *pdev)
 {
 	void __iomem * rng_base;
-	int err;
+	struct device *dev = &pdev->dev;
+	struct resource *res;
 
 	if (!cpu_is_ixp46x()) /* includes IXP455 */
 		return -ENOSYS;
 
-	rng_base = ioremap(0x70002100, 4);
-	if (!rng_base)
-		return -ENOMEM;
-	ixp4xx_rng_ops.priv = (unsigned long)rng_base;
-	err = hwrng_register(&ixp4xx_rng_ops);
-	if (err)
-		iounmap(rng_base);
-
-	return err;
-}
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	rng_base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(rng_base))
+		return PTR_ERR(rng_base);
 
-static void __exit ixp4xx_rng_exit(void)
-{
-	void __iomem * rng_base = (void __iomem *)ixp4xx_rng_ops.priv;
-
-	hwrng_unregister(&ixp4xx_rng_ops);
-	iounmap(rng_base);
+	ixp4xx_rng_ops.priv = (unsigned long)rng_base;
+	return devm_hwrng_register(dev, &ixp4xx_rng_ops);
 }
 
-module_init(ixp4xx_rng_init);
-module_exit(ixp4xx_rng_exit);
+static struct platform_driver ixp4xx_rng_driver = {
+	.driver = {
+		.name = "ixp4xx-hwrandom",
+	},
+	.probe = ixp4xx_rng_probe,
+};
+module_platform_driver(ixp4xx_rng_driver);
 
 MODULE_AUTHOR("Deepak Saxena <dsaxena@plexity.net>");
 MODULE_DESCRIPTION("H/W Pseudo-Random Number Generator (RNG) driver for IXP45x/46x");
-- 
2.30.2

Re: [PATCH 3/5] hw_random: ixp4xx: Turn into a module

[Herbert Xu]

On Tue, May 11, 2021 at 03:29:26PM +0200, Linus Walleij wrote:
> Instead of just initializing always, which will invariably
> create problems on multiplatform builds, turn this driver into
> a module and pass a resource with the memory location.
> The device only exist on the IXP46x so we only register
> the device for the IXP46x SoC.
> 
> Cc: Deepak Saxena <dsaxena@plexity.net>
> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
> ---
> The idea is to apply this through the ARM SoC tree along
> with other IXP4xx refactorings.
> Please tell me if you prefer another solution.
> ---
>  arch/arm/mach-ixp4xx/common.c       | 24 ++++++++++++++++++-
>  drivers/char/hw_random/ixp4xx-rng.c | 37 +++++++++++++----------------
>  2 files changed, 40 insertions(+), 21 deletions(-)

Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt

[PATCH 4/5] hw_random: ixp4xx: Add DT bindings

[Linus Walleij]

This adds device tree bindings for the simple random number
generator found in the IXP46x SoCs.

Cc: Deepak Saxena <dsaxena@plexity.net>
Cc: devicetree@vger.kernel.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
The idea is to apply this through the ARM SoC tree along
with other IXP4xx refactorings.
Please tell me if you prefer another solution.
---
 .../bindings/rng/intel,ixp46x-rng.yaml        | 36 +++++++++++++++++++
 MAINTAINERS                                   |  1 +
 2 files changed, 37 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/rng/intel,ixp46x-rng.yaml

diff --git a/Documentation/devicetree/bindings/rng/intel,ixp46x-rng.yaml b/Documentation/devicetree/bindings/rng/intel,ixp46x-rng.yaml
new file mode 100644
index 000000000000..61963fa9347e
--- /dev/null
+++ b/Documentation/devicetree/bindings/rng/intel,ixp46x-rng.yaml
@@ -0,0 +1,36 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/rng/intel,ixp46x-rng.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Intel IXP46x RNG bindings
+
+description: |
+  The Intel IXP46x has a random number generator at a fixed physical
+  location in memory. Each read is guaranteed to provide a unique
+  32 bit random number.
+
+maintainers:
+  - Linus Walleij <linus.walleij@linaro.org>
+
+properties:
+  compatible:
+    const: intel,ixp46x-rng
+
+  reg:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    rng@70002100 {
+      compatible = "intel,ixp46x-rng";
+      reg = <0x70002100 4>;
+    };
+
diff --git a/MAINTAINERS b/MAINTAINERS
index bd7aff0c120f..cc4bb4e75f04 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -9248,6 +9248,7 @@ F:	include/linux/soc/ixp4xx/qmgr.h
 INTEL IXP4XX RANDOM NUMBER GENERATOR SUPPORT
 M:	Deepak Saxena <dsaxena@plexity.net>
 S:	Maintained
+F:	Documentation/devicetree/bindings/display/intel,ixp46x-rng.yaml
 F:	drivers/char/hw_random/ixp4xx-rng.c
 
 INTEL KEEM BAY DRM DRIVER
-- 
2.30.2

Re: [PATCH 4/5] hw_random: ixp4xx: Add DT bindings

[Rob Herring]

On Tue, 11 May 2021 15:29:27 +0200, Linus Walleij wrote:
> This adds device tree bindings for the simple random number
> generator found in the IXP46x SoCs.
> 
> Cc: Deepak Saxena <dsaxena@plexity.net>
> Cc: devicetree@vger.kernel.org
> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
> ---
> The idea is to apply this through the ARM SoC tree along
> with other IXP4xx refactorings.
> Please tell me if you prefer another solution.
> ---
>  .../bindings/rng/intel,ixp46x-rng.yaml        | 36 +++++++++++++++++++
>  MAINTAINERS                                   |  1 +
>  2 files changed, 37 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/rng/intel,ixp46x-rng.yaml
> 

Reviewed-by: Rob Herring <robh@kernel.org>

[PATCH 5/5] hw_random: ixp4xx: Add OF support

[Linus Walleij]

This makes the hardware random number generator found in
the IXP46x SoCs probe from the device tree.

Cc: Deepak Saxena <dsaxena@plexity.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
The idea is to apply this through the ARM SoC tree along
with other IXP4xx refactorings.
Please tell me if you prefer another solution.
---
 drivers/char/hw_random/ixp4xx-rng.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/char/hw_random/ixp4xx-rng.c b/drivers/char/hw_random/ixp4xx-rng.c
index 8b59aeefd4a4..188854dd16a9 100644
--- a/drivers/char/hw_random/ixp4xx-rng.c
+++ b/drivers/char/hw_random/ixp4xx-rng.c
@@ -19,6 +19,7 @@
 #include <linux/init.h>
 #include <linux/bitops.h>
 #include <linux/hw_random.h>
+#include <linux/of.h>
 #include <linux/soc/ixp4xx/cpu.h>
 
 #include <asm/io.h>
@@ -55,9 +56,18 @@ static int ixp4xx_rng_probe(struct platform_device *pdev)
 	return devm_hwrng_register(dev, &ixp4xx_rng_ops);
 }
 
+static const struct of_device_id ixp4xx_rng_of_match[] = {
+	{
+		.compatible = "intel,ixp46x-rng",
+	},
+	{},
+};
+MODULE_DEVICE_TABLE(of, ixp4xx_rng_of_match);
+
 static struct platform_driver ixp4xx_rng_driver = {
 	.driver = {
 		.name = "ixp4xx-hwrandom",
+		.of_match_table = ixp4xx_rng_of_match,
 	},
 	.probe = ixp4xx_rng_probe,
 };
-- 
2.30.2

Re: [PATCH 5/5] hw_random: ixp4xx: Add OF support

[Herbert Xu]

On Tue, May 11, 2021 at 03:29:28PM +0200, Linus Walleij wrote:
> This makes the hardware random number generator found in
> the IXP46x SoCs probe from the device tree.
> 
> Cc: Deepak Saxena <dsaxena@plexity.net>
> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
> ---
> The idea is to apply this through the ARM SoC tree along
> with other IXP4xx refactorings.
> Please tell me if you prefer another solution.
> ---
>  drivers/char/hw_random/ixp4xx-rng.c | 10 ++++++++++
>  1 file changed, 10 insertions(+)

Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt

Re: [PATCH 1/5] hw_random: ixp4xx: enable compile-testing

[Herbert Xu]

On Tue, May 11, 2021 at 03:29:24PM +0200, Linus Walleij wrote:
> From: Arnd Bergmann <arnd@arndb.de>
> 
> The driver is almost portable already, it just needs to
> include the new header for the cpu definition.
> 
> Cc: Deepak Saxena <dsaxena@plexity.net>
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
> ---
> The idea is to apply this through the ARM SoC tree along
> with other IXP4xx refactorings.
> Please tell me if you prefer another solution.
> ---
>  drivers/char/hw_random/Kconfig      | 2 +-
>  drivers/char/hw_random/ixp4xx-rng.c | 3 +--
>  2 files changed, 2 insertions(+), 3 deletions(-)

Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt