Re: [PATCH v2 2/3] hwrng: exynos - add Samsung Exynos True RNG driver

2017-12-05 Thread PrasannaKumar Muralidharan
Hi Lukasz,

On 27 November 2017 at 15:28, Łukasz Stelmach  wrote:
> Add support for True Random Number Generator found in Samsung Exynos
> 5250+ SoCs.
>
> Signed-off-by: Łukasz Stelmach 
> ---
>  MAINTAINERS  |   7 +
>  drivers/char/hw_random/Kconfig   |  12 ++
>  drivers/char/hw_random/Makefile  |   1 +
>  drivers/char/hw_random/exynos-trng.c | 245 
> +++
>  4 files changed, 265 insertions(+)
>  create mode 100644 drivers/char/hw_random/exynos-trng.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 2811a211632c..992074cca612 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -11780,6 +11780,13 @@ S: Maintained
>  F: drivers/crypto/exynos-rng.c
>  F: Documentation/devicetree/bindings/rng/samsung,exynos-rng4.txt
>
> +SAMSUNG EXYNOS TRUE RANDOM NUMBER GENERATOR (TRNG) DRIVER
> +M: Łukasz Stelmach 
> +L: linux-samsung-...@vger.kernel.org
> +S: Maintained
> +F: drivers/char/hw_random/exynos-trng.c
> +F: Documentation/devicetree/bindings/rng/samsung,exynos5250-trng.txt
> +
>  SAMSUNG FRAMEBUFFER DRIVER
>  M: Jingoo Han 
>  L: linux-fb...@vger.kernel.org
> diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig
> index 95a031e9eced..292e6b36d493 100644
> --- a/drivers/char/hw_random/Kconfig
> +++ b/drivers/char/hw_random/Kconfig
> @@ -449,6 +449,18 @@ config HW_RANDOM_S390
>
>   If unsure, say Y.
>
> +config HW_RANDOM_EXYNOS
> +   tristate "Samsung Exynos True Random Number Generator support"
> +   depends on ARCH_EXYNOS || COMPILE_TEST
> +   default HW_RANDOM
> +   ---help---
> + This driver provides support for the True Random Number
> + Generator available in Exynos SoCs.
> +
> + To compile this driver as a module, choose M here: the module
> + will be called exynos-trng.
> +
> + If unsure, say Y.
>  endif # HW_RANDOM
>
>  config UML_RANDOM
> diff --git a/drivers/char/hw_random/Makefile b/drivers/char/hw_random/Makefile
> index f3728d008fff..5595df97da7a 100644
> --- a/drivers/char/hw_random/Makefile
> +++ b/drivers/char/hw_random/Makefile
> @@ -14,6 +14,7 @@ obj-$(CONFIG_HW_RANDOM_GEODE) += geode-rng.o
>  obj-$(CONFIG_HW_RANDOM_N2RNG) += n2-rng.o
>  n2-rng-y := n2-drv.o n2-asm.o
>  obj-$(CONFIG_HW_RANDOM_VIA) += via-rng.o
> +obj-$(CONFIG_HW_RANDOM_EXYNOS) += exynos-trng.o
>  obj-$(CONFIG_HW_RANDOM_IXP4XX) += ixp4xx-rng.o
>  obj-$(CONFIG_HW_RANDOM_OMAP) += omap-rng.o
>  obj-$(CONFIG_HW_RANDOM_OMAP3_ROM) += omap3-rom-rng.o
> diff --git a/drivers/char/hw_random/exynos-trng.c 
> b/drivers/char/hw_random/exynos-trng.c
> new file mode 100644
> index ..91b2ddb249fa
> --- /dev/null
> +++ b/drivers/char/hw_random/exynos-trng.c
> @@ -0,0 +1,245 @@
> +/*
> + * RNG driver for Exynos TRNGs
> + *
> + * Author: Łukasz Stelmach 
> + *
> + * Copyright 2017 (c) Samsung Electronics Software, Inc.
> + *
> + * Based on the Exynos PRNG driver drivers/crypto/exynos-rng by
> + * Krzysztof Kozłowski 
> + *
> + * 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;
> + *
> + * 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.
> + */
> +
> +#include 
> +#include 
> +#include 
> +#include 
> +#include 
> +#include 
> +#include 
> +#include 
> +#include 
> +#include 
> +#include 
> +
> +#define EXYNOS_TRNG_CLKDIV (0x0)
> +#define EXYNOS_TRNG_CTRL   (0x20)
> +#define EXYNOS_TRNG_POST_CTRL  (0x30)
> +#define EXYNOS_TRNG_ONLINE_CTRL(0x40)
> +#define EXYNOS_TRNG_ONLINE_STAT(0x44)
> +#define EXYNOS_TRNG_ONLINE_MAXCHI2 (0x48)
> +#define EXYNOS_TRNG_FIFO_CTRL  (0x50)
> +#define EXYNOS_TRNG_FIFO_0 (0x80)
> +#define EXYNOS_TRNG_FIFO_1 (0x84)
> +#define EXYNOS_TRNG_FIFO_2 (0x88)
> +#define EXYNOS_TRNG_FIFO_3 (0x8c)
> +#define EXYNOS_TRNG_FIFO_4 (0x90)
> +#define EXYNOS_TRNG_FIFO_5 (0x94)
> +#define EXYNOS_TRNG_FIFO_6 (0x98)
> +#define EXYNOS_TRNG_FIFO_7 (0x9c)
> +#define EXYNOS_TRNG_FIFO_LEN   (8)
> +#define EXYNOS_TRNG_CLOCK_RATE (50)
> +
> +#define TRNG_CTRL_RGNENBIT(31)
> +
> +struct exynos_trng_dev {
> +   struct device*dev;
> +   void __iomem *mem;
> +   struct clk   *clk;
> +   struct hwrng rng;
> +};
> +
> +static int exynos_trng_do_read(struct hwrng *rng, void *data, size_t max,
> +  bool wait)
> +{
> +   struct exynos_trng_dev *trng;
> +   u32 val;
> +
> +   max = min_t(size_t, max, 

Re: [PATCH v2 2/3] hwrng: exynos - add Samsung Exynos True RNG driver

2017-11-27 Thread Krzysztof Kozlowski
On Mon, Nov 27, 2017 at 10:58 AM, Łukasz Stelmach
 wrote:
> Add support for True Random Number Generator found in Samsung Exynos
> 5250+ SoCs.
>
> Signed-off-by: Łukasz Stelmach 
> ---
>  MAINTAINERS  |   7 +
>  drivers/char/hw_random/Kconfig   |  12 ++
>  drivers/char/hw_random/Makefile  |   1 +
>  drivers/char/hw_random/exynos-trng.c | 245 
> +++
>  4 files changed, 265 insertions(+)
>  create mode 100644 drivers/char/hw_random/exynos-trng.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 2811a211632c..992074cca612 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -11780,6 +11780,13 @@ S: Maintained
>  F: drivers/crypto/exynos-rng.c
>  F: Documentation/devicetree/bindings/rng/samsung,exynos-rng4.txt
>
> +SAMSUNG EXYNOS TRUE RANDOM NUMBER GENERATOR (TRNG) DRIVER
> +M: Łukasz Stelmach 
> +L: linux-samsung-...@vger.kernel.org
> +S: Maintained
> +F: drivers/char/hw_random/exynos-trng.c
> +F: Documentation/devicetree/bindings/rng/samsung,exynos5250-trng.txt
> +
>  SAMSUNG FRAMEBUFFER DRIVER
>  M: Jingoo Han 
>  L: linux-fb...@vger.kernel.org
> diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig
> index 95a031e9eced..292e6b36d493 100644
> --- a/drivers/char/hw_random/Kconfig
> +++ b/drivers/char/hw_random/Kconfig
> @@ -449,6 +449,18 @@ config HW_RANDOM_S390
>
>   If unsure, say Y.
>
> +config HW_RANDOM_EXYNOS
> +   tristate "Samsung Exynos True Random Number Generator support"
> +   depends on ARCH_EXYNOS || COMPILE_TEST
> +   default HW_RANDOM
> +   ---help---
> + This driver provides support for the True Random Number
> + Generator available in Exynos SoCs.
> +
> + To compile this driver as a module, choose M here: the module
> + will be called exynos-trng.
> +
> + If unsure, say Y.
>  endif # HW_RANDOM
>
>  config UML_RANDOM
> diff --git a/drivers/char/hw_random/Makefile b/drivers/char/hw_random/Makefile
> index f3728d008fff..5595df97da7a 100644
> --- a/drivers/char/hw_random/Makefile
> +++ b/drivers/char/hw_random/Makefile
> @@ -14,6 +14,7 @@ obj-$(CONFIG_HW_RANDOM_GEODE) += geode-rng.o
>  obj-$(CONFIG_HW_RANDOM_N2RNG) += n2-rng.o
>  n2-rng-y := n2-drv.o n2-asm.o
>  obj-$(CONFIG_HW_RANDOM_VIA) += via-rng.o
> +obj-$(CONFIG_HW_RANDOM_EXYNOS) += exynos-trng.o
>  obj-$(CONFIG_HW_RANDOM_IXP4XX) += ixp4xx-rng.o
>  obj-$(CONFIG_HW_RANDOM_OMAP) += omap-rng.o
>  obj-$(CONFIG_HW_RANDOM_OMAP3_ROM) += omap3-rom-rng.o
> diff --git a/drivers/char/hw_random/exynos-trng.c 
> b/drivers/char/hw_random/exynos-trng.c
> new file mode 100644
> index ..91b2ddb249fa
> --- /dev/null
> +++ b/drivers/char/hw_random/exynos-trng.c
> @@ -0,0 +1,245 @@
> +/*
> + * RNG driver for Exynos TRNGs
> + *
> + * Author: Łukasz Stelmach 
> + *
> + * Copyright 2017 (c) Samsung Electronics Software, Inc.
> + *
> + * Based on the Exynos PRNG driver drivers/crypto/exynos-rng by
> + * Krzysztof Kozłowski 
> + *
> + * 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;
> + *
> + * 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.
> + */
> +
> +#include 
> +#include 
> +#include 
> +#include 
> +#include 
> +#include 
> +#include 
> +#include 
> +#include 
> +#include 
> +#include 
> +
> +#define EXYNOS_TRNG_CLKDIV (0x0)
> +#define EXYNOS_TRNG_CTRL   (0x20)
> +#define EXYNOS_TRNG_POST_CTRL  (0x30)
> +#define EXYNOS_TRNG_ONLINE_CTRL(0x40)
> +#define EXYNOS_TRNG_ONLINE_STAT(0x44)
> +#define EXYNOS_TRNG_ONLINE_MAXCHI2 (0x48)
> +#define EXYNOS_TRNG_FIFO_CTRL  (0x50)
> +#define EXYNOS_TRNG_FIFO_0 (0x80)
> +#define EXYNOS_TRNG_FIFO_1 (0x84)
> +#define EXYNOS_TRNG_FIFO_2 (0x88)
> +#define EXYNOS_TRNG_FIFO_3 (0x8c)
> +#define EXYNOS_TRNG_FIFO_4 (0x90)
> +#define EXYNOS_TRNG_FIFO_5 (0x94)
> +#define EXYNOS_TRNG_FIFO_6 (0x98)
> +#define EXYNOS_TRNG_FIFO_7 (0x9c)
> +#define EXYNOS_TRNG_FIFO_LEN   (8)
> +#define EXYNOS_TRNG_CLOCK_RATE (50)
> +
> +#define TRNG_CTRL_RGNENBIT(31)

Add a EXYNOS prefix and please put it after the register where it is
used (CTRL).

> +
> +struct exynos_trng_dev {
> +   struct device*dev;
> +   void __iomem *mem;
> +   struct clk   *clk;
> +   struct hwrng rng;
> +};
> +
> +static int exynos_trng_do_read(struct hwrng *rng, void *data, size_t max,
> +  bool wait)
> +{
> +   struct exynos_trng_dev 

[PATCH v2 2/3] hwrng: exynos - add Samsung Exynos True RNG driver

2017-11-27 Thread Łukasz Stelmach
Add support for True Random Number Generator found in Samsung Exynos
5250+ SoCs.

Signed-off-by: Łukasz Stelmach 
---
 MAINTAINERS  |   7 +
 drivers/char/hw_random/Kconfig   |  12 ++
 drivers/char/hw_random/Makefile  |   1 +
 drivers/char/hw_random/exynos-trng.c | 245 +++
 4 files changed, 265 insertions(+)
 create mode 100644 drivers/char/hw_random/exynos-trng.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 2811a211632c..992074cca612 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -11780,6 +11780,13 @@ S: Maintained
 F: drivers/crypto/exynos-rng.c
 F: Documentation/devicetree/bindings/rng/samsung,exynos-rng4.txt
 
+SAMSUNG EXYNOS TRUE RANDOM NUMBER GENERATOR (TRNG) DRIVER
+M: Łukasz Stelmach 
+L: linux-samsung-...@vger.kernel.org
+S: Maintained
+F: drivers/char/hw_random/exynos-trng.c
+F: Documentation/devicetree/bindings/rng/samsung,exynos5250-trng.txt
+
 SAMSUNG FRAMEBUFFER DRIVER
 M: Jingoo Han 
 L: linux-fb...@vger.kernel.org
diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig
index 95a031e9eced..292e6b36d493 100644
--- a/drivers/char/hw_random/Kconfig
+++ b/drivers/char/hw_random/Kconfig
@@ -449,6 +449,18 @@ config HW_RANDOM_S390
 
  If unsure, say Y.
 
+config HW_RANDOM_EXYNOS
+   tristate "Samsung Exynos True Random Number Generator support"
+   depends on ARCH_EXYNOS || COMPILE_TEST
+   default HW_RANDOM
+   ---help---
+ This driver provides support for the True Random Number
+ Generator available in Exynos SoCs.
+
+ To compile this driver as a module, choose M here: the module
+ will be called exynos-trng.
+
+ If unsure, say Y.
 endif # HW_RANDOM
 
 config UML_RANDOM
diff --git a/drivers/char/hw_random/Makefile b/drivers/char/hw_random/Makefile
index f3728d008fff..5595df97da7a 100644
--- a/drivers/char/hw_random/Makefile
+++ b/drivers/char/hw_random/Makefile
@@ -14,6 +14,7 @@ obj-$(CONFIG_HW_RANDOM_GEODE) += geode-rng.o
 obj-$(CONFIG_HW_RANDOM_N2RNG) += n2-rng.o
 n2-rng-y := n2-drv.o n2-asm.o
 obj-$(CONFIG_HW_RANDOM_VIA) += via-rng.o
+obj-$(CONFIG_HW_RANDOM_EXYNOS) += exynos-trng.o
 obj-$(CONFIG_HW_RANDOM_IXP4XX) += ixp4xx-rng.o
 obj-$(CONFIG_HW_RANDOM_OMAP) += omap-rng.o
 obj-$(CONFIG_HW_RANDOM_OMAP3_ROM) += omap3-rom-rng.o
diff --git a/drivers/char/hw_random/exynos-trng.c 
b/drivers/char/hw_random/exynos-trng.c
new file mode 100644
index ..91b2ddb249fa
--- /dev/null
+++ b/drivers/char/hw_random/exynos-trng.c
@@ -0,0 +1,245 @@
+/*
+ * RNG driver for Exynos TRNGs
+ *
+ * Author: Łukasz Stelmach 
+ *
+ * Copyright 2017 (c) Samsung Electronics Software, Inc.
+ *
+ * Based on the Exynos PRNG driver drivers/crypto/exynos-rng by
+ * Krzysztof Kozłowski 
+ *
+ * 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;
+ *
+ * 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.
+ */
+
+#include 
+#include 
+#include 
+#include 
+#include 
+#include 
+#include 
+#include 
+#include 
+#include 
+#include 
+
+#define EXYNOS_TRNG_CLKDIV (0x0)
+#define EXYNOS_TRNG_CTRL   (0x20)
+#define EXYNOS_TRNG_POST_CTRL  (0x30)
+#define EXYNOS_TRNG_ONLINE_CTRL(0x40)
+#define EXYNOS_TRNG_ONLINE_STAT(0x44)
+#define EXYNOS_TRNG_ONLINE_MAXCHI2 (0x48)
+#define EXYNOS_TRNG_FIFO_CTRL  (0x50)
+#define EXYNOS_TRNG_FIFO_0 (0x80)
+#define EXYNOS_TRNG_FIFO_1 (0x84)
+#define EXYNOS_TRNG_FIFO_2 (0x88)
+#define EXYNOS_TRNG_FIFO_3 (0x8c)
+#define EXYNOS_TRNG_FIFO_4 (0x90)
+#define EXYNOS_TRNG_FIFO_5 (0x94)
+#define EXYNOS_TRNG_FIFO_6 (0x98)
+#define EXYNOS_TRNG_FIFO_7 (0x9c)
+#define EXYNOS_TRNG_FIFO_LEN   (8)
+#define EXYNOS_TRNG_CLOCK_RATE (50)
+
+#define TRNG_CTRL_RGNENBIT(31)
+
+struct exynos_trng_dev {
+   struct device*dev;
+   void __iomem *mem;
+   struct clk   *clk;
+   struct hwrng rng;
+};
+
+static int exynos_trng_do_read(struct hwrng *rng, void *data, size_t max,
+  bool wait)
+{
+   struct exynos_trng_dev *trng;
+   u32 val;
+
+   max = min_t(size_t, max, (EXYNOS_TRNG_FIFO_LEN * 4));
+
+   trng = (struct exynos_trng_dev *)rng->priv;
+
+   __raw_writel(max * 8, trng->mem + EXYNOS_TRNG_FIFO_CTRL);
+   val = readl_poll_timeout(trng->mem + EXYNOS_TRNG_FIFO_CTRL, val,
+val == 0, 200, 100);
+   if (val < 0)
+   return val;
+
+   memcpy_fromio(data, trng->mem +