[PATCH v6 0/3] hwrng: bcm2835: add reset support

[PATCH v6 0/3] hwrng: bcm2835: add reset support

[Álvaro Fernández Rojas]

Some devices may need to perform a reset before using the RNG, such as the
BCM6368.

v6: fix dt-bindings documentation, add patch makings clocks mandatory for
 BCM6368.
v5: remove reset_control_rearm() and apply on latest herbert/cryptodev-2.6.git.
v4: fix documentation, add reset_control_rearm().
v3: make resets required if brcm,bcm6368-rng.
v2: document reset support.

Álvaro Fernández Rojas (3):
  dt-bindings: rng: bcm2835: add clock constraints
  dt-bindings: rng: bcm2835: document reset support
  hwrng: bcm2835: add reset support

 .../devicetree/bindings/rng/brcm,bcm2835.yaml | 21 +++++++++++++++++++
 drivers/char/hw_random/bcm2835-rng.c          | 10 +++++++++
 2 files changed, 31 insertions(+)

-- 
2.20.1

[PATCH v6 1/3] dt-bindings: rng: bcm2835: add clock constraints

[Álvaro Fernández Rojas]

brcm,bcm6368-rng controllers require enabling the IPSEC clock in order to get
a functional RNG.

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
---
 v6: add new patch making clocks mandatory for BCM6368.

 .../devicetree/bindings/rng/brcm,bcm2835.yaml          | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/Documentation/devicetree/bindings/rng/brcm,bcm2835.yaml b/Documentation/devicetree/bindings/rng/brcm,bcm2835.yaml
index c147900f9041..5174492e22f3 100644
--- a/Documentation/devicetree/bindings/rng/brcm,bcm2835.yaml
+++ b/Documentation/devicetree/bindings/rng/brcm,bcm2835.yaml
@@ -35,6 +35,16 @@ required:
   - compatible
   - reg
 
+if:
+  properties:
+    compatible:
+      enum:
+        - brcm,bcm6368-rng
+then:
+  required:
+    - clocks
+    - clock-names
+
 additionalProperties: false
 
 examples:
-- 
2.20.1

[PATCH v6 2/3] dt-bindings: rng: bcm2835: document reset support

[Álvaro Fernández Rojas]

brcm,bcm6368-rng controllers require resetting the IPSEC clock in order to get
a functional RNG.

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
---
 v6: fix dt-bindings warnings.
 v5: no changes.
 v4: pass dt_binding_check.
 v3: make resets required if brcm,bcm6368-rng.
 v2: document reset support.

 .../devicetree/bindings/rng/brcm,bcm2835.yaml         | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/Documentation/devicetree/bindings/rng/brcm,bcm2835.yaml b/Documentation/devicetree/bindings/rng/brcm,bcm2835.yaml
index 5174492e22f3..6da674666d45 100644
--- a/Documentation/devicetree/bindings/rng/brcm,bcm2835.yaml
+++ b/Documentation/devicetree/bindings/rng/brcm,bcm2835.yaml
@@ -28,6 +28,12 @@ properties:
   clock-names:
     const: ipsec
 
+  resets:
+    maxItems: 1
+
+  reset-names:
+    const: ipsec
+
   interrupts:
     maxItems: 1
 
@@ -44,6 +50,8 @@ then:
   required:
     - clocks
     - clock-names
+    - resets
+    - reset-names
 
 additionalProperties: false
 
@@ -68,4 +76,7 @@ examples:
 
         clocks = <&periph_clk 18>;
         clock-names = "ipsec";
+
+        resets = <&periph_rst 4>;
+        reset-names = "ipsec";
     };
-- 
2.20.1

[PATCH v6 3/3] hwrng: bcm2835: add reset support

[Álvaro Fernández Rojas]

BCM6368 devices need to reset the IPSEC controller in order to generate true
random numbers.

This is what BCM6368 produces without a reset:
root@OpenWrt:/# cat /dev/hwrng | rngtest -c 1000
rngtest 6.10
Copyright (c) 2004 by Henrique de Moraes Holschuh
This is free software; see the source for copying conditions.  There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

rngtest: starting FIPS tests...
rngtest: bits received from input: 20000032
rngtest: FIPS 140-2 successes: 0
rngtest: FIPS 140-2 failures: 1000
rngtest: FIPS 140-2(2001-10-10) Monobit: 2
rngtest: FIPS 140-2(2001-10-10) Poker: 1000
rngtest: FIPS 140-2(2001-10-10) Runs: 1000
rngtest: FIPS 140-2(2001-10-10) Long run: 30
rngtest: FIPS 140-2(2001-10-10) Continuous run: 0
rngtest: input channel speed: (min=37.253; avg=320.827; max=635.783)Mibits/s
rngtest: FIPS tests speed: (min=12.141; avg=15.034; max=16.428)Mibits/s
rngtest: Program run time: 1336176 microseconds

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
---
 v6: fix commit description.
 v5: remove reset_control_rearm().
 v4: add reset_control_rearm().
 v3: no changes.
 v2: no changes.

 drivers/char/hw_random/bcm2835-rng.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/char/hw_random/bcm2835-rng.c b/drivers/char/hw_random/bcm2835-rng.c
index be5be395b341..e7dd457e9b22 100644
--- a/drivers/char/hw_random/bcm2835-rng.c
+++ b/drivers/char/hw_random/bcm2835-rng.c
@@ -13,6 +13,7 @@
 #include <linux/platform_device.h>
 #include <linux/printk.h>
 #include <linux/clk.h>
+#include <linux/reset.h>
 
 #define RNG_CTRL	0x0
 #define RNG_STATUS	0x4
@@ -32,6 +33,7 @@ struct bcm2835_rng_priv {
 	void __iomem *base;
 	bool mask_interrupts;
 	struct clk *clk;
+	struct reset_control *reset;
 };
 
 static inline struct bcm2835_rng_priv *to_rng_priv(struct hwrng *rng)
@@ -92,6 +94,10 @@ static int bcm2835_rng_init(struct hwrng *rng)
 	if (ret)
 		return ret;
 
+	ret = reset_control_reset(priv->reset);
+	if (ret)
+		return ret;
+
 	if (priv->mask_interrupts) {
 		/* mask the interrupt */
 		val = rng_readl(priv, RNG_INT_MASK);
@@ -156,6 +162,10 @@ static int bcm2835_rng_probe(struct platform_device *pdev)
 	if (IS_ERR(priv->clk))
 		return PTR_ERR(priv->clk);
 
+	priv->reset = devm_reset_control_get_optional_exclusive(dev, NULL);
+	if (IS_ERR(priv->reset))
+		return PTR_ERR(priv->reset);
+
 	priv->rng.name = pdev->name;
 	priv->rng.init = bcm2835_rng_init;
 	priv->rng.read = bcm2835_rng_read;
-- 
2.20.1

Re: [PATCH v6 3/3] hwrng: bcm2835: add reset support

[Philipp Zabel]

On Fri, 2021-03-05 at 08:01 +0100, Álvaro Fernández Rojas wrote:
> BCM6368 devices need to reset the IPSEC controller in order to generate true
> random numbers.
> 
> This is what BCM6368 produces without a reset:
> root@OpenWrt:/# cat /dev/hwrng | rngtest -c 1000
> rngtest 6.10
> Copyright (c) 2004 by Henrique de Moraes Holschuh
> This is free software; see the source for copying conditions.  There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
> 
> rngtest: starting FIPS tests...
> rngtest: bits received from input: 20000032
> rngtest: FIPS 140-2 successes: 0
> rngtest: FIPS 140-2 failures: 1000
> rngtest: FIPS 140-2(2001-10-10) Monobit: 2
> rngtest: FIPS 140-2(2001-10-10) Poker: 1000
> rngtest: FIPS 140-2(2001-10-10) Runs: 1000
> rngtest: FIPS 140-2(2001-10-10) Long run: 30
> rngtest: FIPS 140-2(2001-10-10) Continuous run: 0
> rngtest: input channel speed: (min=37.253; avg=320.827; max=635.783)Mibits/s
> rngtest: FIPS tests speed: (min=12.141; avg=15.034; max=16.428)Mibits/s
> rngtest: Program run time: 1336176 microseconds
> 
> Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>

Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>

regards
Philipp

> ---
>  v6: fix commit description.
>  v5: remove reset_control_rearm().
>  v4: add reset_control_rearm().
>  v3: no changes.
>  v2: no changes.
> 
>  drivers/char/hw_random/bcm2835-rng.c | 10 ++++++++++
>  1 file changed, 10 insertions(+)
> 
> diff --git a/drivers/char/hw_random/bcm2835-rng.c b/drivers/char/hw_random/bcm2835-rng.c
> index be5be395b341..e7dd457e9b22 100644
> --- a/drivers/char/hw_random/bcm2835-rng.c
> +++ b/drivers/char/hw_random/bcm2835-rng.c
> @@ -13,6 +13,7 @@
>  #include <linux/platform_device.h>
>  #include <linux/printk.h>
>  #include <linux/clk.h>
> +#include <linux/reset.h>
>  
>  #define RNG_CTRL	0x0
>  #define RNG_STATUS	0x4
> @@ -32,6 +33,7 @@ struct bcm2835_rng_priv {
>  	void __iomem *base;
>  	bool mask_interrupts;
>  	struct clk *clk;
> +	struct reset_control *reset;
>  };
>  
>  static inline struct bcm2835_rng_priv *to_rng_priv(struct hwrng *rng)
> @@ -92,6 +94,10 @@ static int bcm2835_rng_init(struct hwrng *rng)
>  	if (ret)
>  		return ret;
>  
> +	ret = reset_control_reset(priv->reset);
> +	if (ret)
> +		return ret;
> +
>  	if (priv->mask_interrupts) {
>  		/* mask the interrupt */
>  		val = rng_readl(priv, RNG_INT_MASK);
> @@ -156,6 +162,10 @@ static int bcm2835_rng_probe(struct platform_device *pdev)
>  	if (IS_ERR(priv->clk))
>  		return PTR_ERR(priv->clk);
>  
> +	priv->reset = devm_reset_control_get_optional_exclusive(dev, NULL);
> +	if (IS_ERR(priv->reset))
> +		return PTR_ERR(priv->reset);
> +
>  	priv->rng.name = pdev->name;
>  	priv->rng.init = bcm2835_rng_init;
>  	priv->rng.read = bcm2835_rng_read;

Re: [PATCH v6 1/3] dt-bindings: rng: bcm2835: add clock constraints

[Rob Herring]

On Fri, 05 Mar 2021 08:01:30 +0100, Álvaro Fernández Rojas wrote:
> brcm,bcm6368-rng controllers require enabling the IPSEC clock in order to get
> a functional RNG.
> 
> Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
> ---
>  v6: add new patch making clocks mandatory for BCM6368.
> 
>  .../devicetree/bindings/rng/brcm,bcm2835.yaml          | 10 ++++++++++
>  1 file changed, 10 insertions(+)
> 

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

Re: [PATCH v6 2/3] dt-bindings: rng: bcm2835: document reset support

[Rob Herring]

On Fri, 05 Mar 2021 08:01:31 +0100, Álvaro Fernández Rojas wrote:
> brcm,bcm6368-rng controllers require resetting the IPSEC clock in order to get
> a functional RNG.
> 
> Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
> ---
>  v6: fix dt-bindings warnings.
>  v5: no changes.
>  v4: pass dt_binding_check.
>  v3: make resets required if brcm,bcm6368-rng.
>  v2: document reset support.
> 
>  .../devicetree/bindings/rng/brcm,bcm2835.yaml         | 11 +++++++++++
>  1 file changed, 11 insertions(+)
> 

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

Re: [PATCH v6 3/3] hwrng: bcm2835: add reset support

[Florian Fainelli]

On 3/4/21 11:01 PM, Álvaro Fernández Rojas wrote:
> BCM6368 devices need to reset the IPSEC controller in order to generate true
> random numbers.
> 
> This is what BCM6368 produces without a reset:
> root@OpenWrt:/# cat /dev/hwrng | rngtest -c 1000
> rngtest 6.10
> Copyright (c) 2004 by Henrique de Moraes Holschuh
> This is free software; see the source for copying conditions.  There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
> 
> rngtest: starting FIPS tests...
> rngtest: bits received from input: 20000032
> rngtest: FIPS 140-2 successes: 0
> rngtest: FIPS 140-2 failures: 1000
> rngtest: FIPS 140-2(2001-10-10) Monobit: 2
> rngtest: FIPS 140-2(2001-10-10) Poker: 1000
> rngtest: FIPS 140-2(2001-10-10) Runs: 1000
> rngtest: FIPS 140-2(2001-10-10) Long run: 30
> rngtest: FIPS 140-2(2001-10-10) Continuous run: 0
> rngtest: input channel speed: (min=37.253; avg=320.827; max=635.783)Mibits/s
> rngtest: FIPS tests speed: (min=12.141; avg=15.034; max=16.428)Mibits/s
> rngtest: Program run time: 1336176 microseconds
> 
> Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>

Acked-by: Florian Fainelli <f.fainelli@gmail.com>
-- 
Florian

Re: [PATCH v6 1/3] dt-bindings: rng: bcm2835: add clock constraints

[Florian Fainelli]

On 3/4/21 11:01 PM, Álvaro Fernández Rojas wrote:
> brcm,bcm6368-rng controllers require enabling the IPSEC clock in order to get
> a functional RNG.
> 
> Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>

Acked-by: Florian Fainelli <f.fainelli@gmail.com>
-- 
Florian

Re: [PATCH v6 2/3] dt-bindings: rng: bcm2835: document reset support

[Florian Fainelli]

On 3/4/21 11:01 PM, Álvaro Fernández Rojas wrote:
> brcm,bcm6368-rng controllers require resetting the IPSEC clock in order to get
> a functional RNG.
> 
> Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>

Acked-by: Florian Fainelli <f.fainelli@gmail.com>
-- 
Florian

Re: [PATCH v6 0/3] hwrng: bcm2835: add reset support

[Herbert Xu]

On Fri, Mar 05, 2021 at 08:01:29AM +0100, Álvaro Fernández Rojas wrote:
> Some devices may need to perform a reset before using the RNG, such as the
> BCM6368.
> 
> v6: fix dt-bindings documentation, add patch makings clocks mandatory for
>  BCM6368.
> v5: remove reset_control_rearm() and apply on latest herbert/cryptodev-2.6.git.
> v4: fix documentation, add reset_control_rearm().
> v3: make resets required if brcm,bcm6368-rng.
> v2: document reset support.
> 
> Álvaro Fernández Rojas (3):
>   dt-bindings: rng: bcm2835: add clock constraints
>   dt-bindings: rng: bcm2835: document reset support
>   hwrng: bcm2835: add reset support
> 
>  .../devicetree/bindings/rng/brcm,bcm2835.yaml | 21 +++++++++++++++++++
>  drivers/char/hw_random/bcm2835-rng.c          | 10 +++++++++
>  2 files changed, 31 insertions(+)

All applied.  Thanks.
-- 
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