[PATCH 1/2] nomadik hwrng: Add clock support

[PATCH 1/2] nomadik hwrng: Add clock support

[srinidhi kasagar]

This adds the clock support to the Nomadik RNG driver

Signed-off-by: srinidhi kasagar <srinidhi.kasagar@stericsson.com>
Acked-by: Linus Walleij <linus.walleij@stericsson.com>
---
 drivers/char/hw_random/nomadik-rng.c |   17 +++++++++++++++++
 1 files changed, 17 insertions(+), 0 deletions(-)

diff --git a/drivers/char/hw_random/nomadik-rng.c b/drivers/char/hw_random/nomadik-rng.c
index a8b4c40..ae094c1 100644
--- a/drivers/char/hw_random/nomadik-rng.c
+++ b/drivers/char/hw_random/nomadik-rng.c
@@ -15,6 +15,10 @@
 #include <linux/amba/bus.h>
 #include <linux/hw_random.h>
 #include <linux/io.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+
+struct clk *rng_clk;
 
 static int nmk_rng_read(struct hwrng *rng, void *data, size_t max, bool wait)
 {
@@ -40,6 +44,15 @@ static int nmk_rng_probe(struct amba_device *dev, struct amba_id *id)
 	void __iomem *base;
 	int ret;
 
+	rng_clk = clk_get(&dev->dev, NULL);
+	if (IS_ERR(rng_clk)) {
+		dev_err(&dev->dev, "could not get rng clock\n");
+		ret = PTR_ERR(rng_clk);
+		return ret;
+	}
+
+	clk_enable(rng_clk);
+
 	ret = amba_request_regions(dev, dev->dev.init_name);
 	if (ret)
 		return ret;
@@ -57,6 +70,8 @@ out_unmap:
 	iounmap(base);
 out_release:
 	amba_release_regions(dev);
+	clk_disable(rng_clk);
+	clk_put(rng_clk);
 	return ret;
 }
 
@@ -66,6 +81,8 @@ static int nmk_rng_remove(struct amba_device *dev)
 	hwrng_unregister(&nmk_rng);
 	iounmap(base);
 	amba_release_regions(dev);
+	clk_disable(rng_clk);
+	clk_put(rng_clk);
 	return 0;
 }
 
-- 
1.6.3.3

[PATCH 1/2] nomadik hwrng: Add clock support

[Matt Mackall]

On Tue, 2010-05-11 at 12:25 +0530, srinidhi kasagar wrote:
> This adds the clock support to the Nomadik RNG driver
> 
> Signed-off-by: srinidhi kasagar <srinidhi.kasagar@stericsson.com>
> Acked-by: Linus Walleij <linus.walleij@stericsson.com>

Looks good to me. Herbert, please queue this.

Acked-by: Matt Mackall <mpm@selenic.com>

> ---
>  drivers/char/hw_random/nomadik-rng.c |   17 +++++++++++++++++
>  1 files changed, 17 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/char/hw_random/nomadik-rng.c b/drivers/char/hw_random/nomadik-rng.c
> index a8b4c40..ae094c1 100644
> --- a/drivers/char/hw_random/nomadik-rng.c
> +++ b/drivers/char/hw_random/nomadik-rng.c
> @@ -15,6 +15,10 @@
>  #include <linux/amba/bus.h>
>  #include <linux/hw_random.h>
>  #include <linux/io.h>
> +#include <linux/clk.h>
> +#include <linux/err.h>
> +
> +struct clk *rng_clk;
>  
>  static int nmk_rng_read(struct hwrng *rng, void *data, size_t max, bool wait)
>  {
> @@ -40,6 +44,15 @@ static int nmk_rng_probe(struct amba_device *dev, struct amba_id *id)
>  	void __iomem *base;
>  	int ret;
>  
> +	rng_clk = clk_get(&dev->dev, NULL);
> +	if (IS_ERR(rng_clk)) {
> +		dev_err(&dev->dev, "could not get rng clock\n");
> +		ret = PTR_ERR(rng_clk);
> +		return ret;
> +	}
> +
> +	clk_enable(rng_clk);
> +
>  	ret = amba_request_regions(dev, dev->dev.init_name);
>  	if (ret)
>  		return ret;
> @@ -57,6 +70,8 @@ out_unmap:
>  	iounmap(base);
>  out_release:
>  	amba_release_regions(dev);
> +	clk_disable(rng_clk);
> +	clk_put(rng_clk);
>  	return ret;
>  }
>  
> @@ -66,6 +81,8 @@ static int nmk_rng_remove(struct amba_device *dev)
>  	hwrng_unregister(&nmk_rng);
>  	iounmap(base);
>  	amba_release_regions(dev);
> +	clk_disable(rng_clk);
> +	clk_put(rng_clk);
>  	return 0;
>  }
>  



-- 
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[PATCH 1/2] nomadik hwrng: Add clock support

[Alessandro Rubini]

> Looks good to me. Herbert, please queue this.

There are two details wrong, I hope Srinidhi sent V2 soon after this V1.

>> +struct clk *rng_clk;

This should be static.

The other problem is that there is no clock associated to this device,
it is only added by the later 2/2 patch.  So the rng stops working
with this patch alone, with this error:

>> +	rng_clk = clk_get(&dev->dev, NULL);
>> +	if (IS_ERR(rng_clk)) {
>> +		dev_err(&dev->dev, "could not get rng clock\n");
>> +		ret = PTR_ERR(rng_clk);
>> +		return ret;
>> +	}

I think the two patches  must be split differently. However, it's just
two minor details, so I am not against applying as-is, if the relevant
maintainer chooses to.

Thanks
/alessandro

[PATCH 1/2] nomadik hwrng: Add clock support

[Herbert Xu]

On Wed, May 12, 2010 at 11:08:46PM +0200, Alessandro Rubini wrote:
>
> I think the two patches  must be split differently. However, it's just
> two minor details, so I am not against applying as-is, if the relevant
> maintainer chooses to.

I think resplitting them should be done as bisectibility is pretty
important.

Thanks!
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