[PATCH 1/2] hw_random: mxc-rnga: Adapt clocks to new i.mx clock framework

[PATCH 1/2] hw_random: mxc-rnga: Adapt clocks to new i.mx clock framework

[Fabio Estevam]

Adapt clocks to the new i.mx clock framework and fix the following warning:
                             
------------[ cut here ]------------                                            
WARNING: at drivers/clk/clk.c:511 __clk_enable+0x9c/0xac()                      
Modules linked in:                                                              
Backtrace:                                                                      
[<800124c8>] (dump_backtrace+0x0/0x10c) from [<804172dc>] (dump_stack+0x18/0x1c)
 r7:00000009 r6:000001ff r5:8032cb50 r4:00000000                                
[<804172c4>] (dump_stack+0x0/0x1c) from [<80021834>] (warn_slowpath_common+0x54)
[<800217e0>] (warn_slowpath_common+0x0/0x6c) from [<80021870>] (warn_slowpath_n)
 r9:80581cac r8:8700a9c0 r7:805ab070 r6:80000013 r5:806133d4                    
r4:8700a9c0                                                                     
[<8002184c>] (warn_slowpath_null+0x0/0x2c) from [<8032cb50>] (__clk_enable+0x9c)
[<8032cab4>] (__clk_enable+0x0/0xac) from [<8032cb88>] (clk_enable+0x28/0x44)   
 r5:806133d4 r4:8700a9c0                                                        
[<8032cb60>] (clk_enable+0x0/0x44) from [<80560f14>] (mxc_rnga_probe+0x68/0x164)
 r7:805ab070 r6:8706ec00 r5:80611314 r4:00000000                                
[<80560eac>] (mxc_rnga_probe+0x0/0x164) from [<8025914c>] (platform_drv_probe+0)
[<8025912c>] (platform_drv_probe+0x0/0x24) from [<80257c7c>] (driver_probe_devi)
[<80257bfc>] (driver_probe_device+0x0/0x204) from [<80257e94>] (__driver_attach)
 r9:80581cac r8:0000008e r7:00000000 r6:8706ec3c r5:805ab070                    
r4:8706ec08                                                                     
[<80257e00>] (__driver_attach+0x0/0x98) from [<8025642c>] (bus_for_each_dev+0x6)
 r7:00000000 r6:80257e00 r5:87035e98 r4:805ab070                                
[<802563c4>] (bus_for_each_dev+0x0/0x94) from [<80257adc>] (driver_attach+0x20/)
 r7:00000000 r6:873f2380 r5:805ab338 r4:805ab070                                
[<80257abc>] (driver_attach+0x0/0x28) from [<80256d50>] (bus_add_driver+0x18c/0)
[<80256bc4>] (bus_add_driver+0x0/0x268) from [<802584c4>] (driver_register+0x80)
[<80258444>] (driver_register+0x0/0x134) from [<802594f4>] (platform_driver_reg)
 r7:00000000 r6:805c2e00 r5:00000007 r4:805ab05c                                
[<802594a8>] (platform_driver_register+0x0/0x60) from [<80259528>] (platform_dr)
[<80259508>] (platform_driver_probe+0x0/0xa4) from [<80560ea0>] (mod_init+0x18/)
 r7:00000000 r6:805c2e00 r5:00000007 r4:87034000                                
[<80560e88>] (mod_init+0x0/0x24) from [<800086b4>] (do_one_initcall+0x40/0x194) 
[<80008674>] (do_one_initcall+0x0/0x194) from [<8053d3f4>] (kernel_init+0xfc/0x)
[<8053d2f8>] (kernel_init+0x0/0x1cc) from [<80027190>] (do_exit+0x0/0x7ec)      
---[ end trace 4198eed02050f461 ]---                                            
mxc_rnga mxc_rnga: MXC RNGA Registered

Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Herbert Xu <herbert@gondor.apana.org.au> 
Cc: <linux-kernel@vger.kernel.org>
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
---
 drivers/char/hw_random/mxc-rnga.c |    8 ++++----
 1 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/char/hw_random/mxc-rnga.c b/drivers/char/hw_random/mxc-rnga.c
index 85074de..c49c0b8 100644
--- a/drivers/char/hw_random/mxc-rnga.c
+++ b/drivers/char/hw_random/mxc-rnga.c
@@ -152,14 +152,14 @@ static int __init mxc_rnga_probe(struct platform_device *pdev)
 	if (rng_dev)
 		return -EBUSY;
 
-	clk = clk_get(&pdev->dev, "rng");
+	clk = clk_get(&pdev->dev, NULL);
 	if (IS_ERR(clk)) {
 		dev_err(&pdev->dev, "Could not get rng_clk!\n");
 		err = PTR_ERR(clk);
 		goto out;
 	}
 
-	clk_enable(clk);
+	clk_prepare_enable(clk);
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	if (!res) {
@@ -201,7 +201,7 @@ err_ioremap:
 	release_mem_region(res->start, resource_size(res));
 
 err_region:
-	clk_disable(clk);
+	clk_disable_unprepare(clk);
 	clk_put(clk);
 
 out:
@@ -212,7 +212,7 @@ static int __exit mxc_rnga_remove(struct platform_device *pdev)
 {
 	struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	void __iomem *rng_base = (void __iomem *)mxc_rnga.priv;
-	struct clk *clk = clk_get(&pdev->dev, "rng");
+	struct clk *clk = clk_get(&pdev->dev, NULL);
 
 	hwrng_unregister(&mxc_rnga);
 
-- 
1.7.1

Re: [PATCH 1/2] hw_random: mxc-rnga: Adapt clocks to new i.mx clock framework

[Sascha Hauer]

On Fri, Jul 06, 2012 at 05:20:19PM -0300, Fabio Estevam wrote:
> Cc: Theodore Ts'o <tytso@mit.edu>
> Cc: Herbert Xu <herbert@gondor.apana.org.au> 
> Cc: <linux-kernel@vger.kernel.org>
> Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
> ---
>  drivers/char/hw_random/mxc-rnga.c |    8 ++++----
>  1 files changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/char/hw_random/mxc-rnga.c b/drivers/char/hw_random/mxc-rnga.c
> index 85074de..c49c0b8 100644
> --- a/drivers/char/hw_random/mxc-rnga.c
> +++ b/drivers/char/hw_random/mxc-rnga.c
> @@ -152,14 +152,14 @@ static int __init mxc_rnga_probe(struct platform_device *pdev)
>  	if (rng_dev)
>  		return -EBUSY;
>  
> -	clk = clk_get(&pdev->dev, "rng");
> +	clk = clk_get(&pdev->dev, NULL);
>  	if (IS_ERR(clk)) {
>  		dev_err(&pdev->dev, "Could not get rng_clk!\n");
>  		err = PTR_ERR(clk);
>  		goto out;
>  	}
>  
> -	clk_enable(clk);
> +	clk_prepare_enable(clk);
>  
>  	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>  	if (!res) {
> @@ -201,7 +201,7 @@ err_ioremap:
>  	release_mem_region(res->start, resource_size(res));
>  
>  err_region:
> -	clk_disable(clk);
> +	clk_disable_unprepare(clk);
>  	clk_put(clk);
>  
>  out:
> @@ -212,7 +212,7 @@ static int __exit mxc_rnga_remove(struct platform_device *pdev)
>  {
>  	struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>  	void __iomem *rng_base = (void __iomem *)mxc_rnga.priv;
> -	struct clk *clk = clk_get(&pdev->dev, "rng");
> +	struct clk *clk = clk_get(&pdev->dev, NULL);

Uhh, that's a driver bug that should be fixed. Although right now there
is no reference counting for clocks, the driver should keep the clk
internally instead of simply calling clk_get whenever it needs access to
a clk.

Sascha

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Re: [PATCH 1/2] hw_random: mxc-rnga: Adapt clocks to new i.mx clock framework

[Fabio Estevam]

On Mon, Jul 9, 2012 at 4:41 AM, Sascha Hauer <s.hauer@pengutronix.de> wrote:

> Uhh, that's a driver bug that should be fixed. Although right now there
> is no reference counting for clocks, the driver should keep the clk
> internally instead of simply calling clk_get whenever it needs access to
> a clk.

Yes, I just sent a fix for this.