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[PATCH v2 0/4] hw rng support for NSP SoC

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  [PATCH v2 0/4] hw rng support for NSP SoC Yendapally Reddy Dhananjaya Reddy <yendapally.reddy@broadcom.com> - 2016-05-27 12:20 +0200
    [PATCH v2 3/4] ARM: dts: nsp: Add rng device tree entry Yendapally Reddy Dhananjaya Reddy <yendapally.reddy@broadcom.com> - 2016-05-27 12:20 +0200
    [PATCH v2 4/4] hwrng: bcm2835: Read as much data as available Yendapally Reddy Dhananjaya Reddy <yendapally.reddy@broadcom.com> - 2016-05-27 12:20 +0200

#1407979 — [PATCH v2 0/4] hw rng support for NSP SoC

This patchset contains the hw random number generator support for the
Broadcom's NSP SoC. The block is similar to the block available in
bcm2835 with different default interrupt mask value. Due to lack of
documentation, I cannot confirm the interrupt mask register details
in bcm2835. In an effort to not break the existing functionality of
bcm2835, I used a different compatible string to mask the interrupt
for NSP SoC. Please let me know. Also supported providing requested
number of random numbers instead of static size of four bytes.

The first patch contains the documentation changes and the second patch
contains the support for rng available in NSP SoC. The third patch
contains the device tree changes for NSP SoC. The fourth patch contains
the support for reading requested number of random numbers.

This patch set has been tested on NSP bcm958625HR board.
This patch set is based on v4.6.0-rc1 and is available from github
repo: https://github.com/Broadcom/cygnus-linux.git
branch: nsp-rng-v2

Changes since v1

Addressed the review comments from Eric
Added acked by Eric

Yendapally Reddy Dhananjaya Reddy (4):
  dt-bindings: rng: Northstar Plus SoC rng bindings
  hwrng: bcm2835: Support Broadcom NSP SoC rng
  ARM: dts: nsp: Add rng device tree entry
  hwrng: bcm2835: Read as much data as available

 .../devicetree/bindings/rng/brcm,bcm2835.txt       |  7 +++-
 arch/arm/boot/dts/bcm-nsp.dtsi                     |  5 +++
 drivers/char/hw_random/Kconfig                     |  2 +-
 drivers/char/hw_random/bcm2835-rng.c               | 46 +++++++++++++++++++---
 4 files changed, 52 insertions(+), 8 deletions(-)

-- 
2.1.0

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#1407980 — [PATCH v2 3/4] ARM: dts: nsp: Add rng device tree entry

Add support for the random number generator to the Northstar Plus
SoC device tree.

Signed-off-by: Yendapally Reddy Dhananjaya Reddy <yendapally.reddy@broadcom.com>
---
 arch/arm/boot/dts/bcm-nsp.dtsi | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/arm/boot/dts/bcm-nsp.dtsi b/arch/arm/boot/dts/bcm-nsp.dtsi
index def9e78..1ed829e 100644
--- a/arch/arm/boot/dts/bcm-nsp.dtsi
+++ b/arch/arm/boot/dts/bcm-nsp.dtsi
@@ -206,6 +206,11 @@
 			brcm,nand-has-wp;
 		};
 
+		rng: rng@33000 {
+			compatible = "brcm,bcm-nsp-rng";
+			reg = <0x33000 0x14>;
+		};
+
 		ccbtimer0: timer@34000 {
 			compatible = "arm,sp804";
 			reg = <0x34000 0x1000>;
-- 
2.1.0

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#1407981 — [PATCH v2 4/4] hwrng: bcm2835: Read as much data as available

Read the requested number of data from the fifo

Signed-off-by: Yendapally Reddy Dhananjaya Reddy <yendapally.reddy@broadcom.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
---
 drivers/char/hw_random/bcm2835-rng.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/char/hw_random/bcm2835-rng.c b/drivers/char/hw_random/bcm2835-rng.c
index b1e8b78..75ca820 100644
--- a/drivers/char/hw_random/bcm2835-rng.c
+++ b/drivers/char/hw_random/bcm2835-rng.c
@@ -43,6 +43,8 @@ static int bcm2835_rng_read(struct hwrng *rng, void *buf, size_t max,
 			       bool wait)
 {
 	void __iomem *rng_base = (void __iomem *)rng->priv;
+	u32 max_words = max / sizeof(u32);
+	u32 num_words, count;
 
 	while ((__raw_readl(rng_base + RNG_STATUS) >> 24) == 0) {
 		if (!wait)
@@ -50,8 +52,14 @@ static int bcm2835_rng_read(struct hwrng *rng, void *buf, size_t max,
 		cpu_relax();
 	}
 
-	*(u32 *)buf = __raw_readl(rng_base + RNG_DATA);
-	return sizeof(u32);
+	num_words = readl(rng_base + RNG_STATUS) >> 24;
+	if (num_words > max_words)
+		num_words = max_words;
+
+	for (count = 0; count < num_words; count++)
+		((u32 *)buf)[count] = readl(rng_base + RNG_DATA);
+
+	return num_words * sizeof(u32);
 }
 
 static struct hwrng bcm2835_rng_ops = {
-- 
2.1.0

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