Subject: [PATCH] ep93xx: move clock initialization earlier

From: [email-masked] (Ryan Mallon)
Date: Thu, 02 Sep 2010 08:55:01 +1200

On 09/02/2010 05:51 AM, Mika Westerberg wrote:
> Commit 7cfe24947 ("ARM: AMBA: Add pclk support to AMBA bus infrastructure")
> changed AMBA bus to handle the PCLK automatically. However, in EP93xx clock
> initialization is arch_initcall() which is done later than AMBA device
> identification. This causes amba_get_enable_pclk() to fail resulting device
> where UARTs are not functional.
> 
> So move clock initialization code before any AMBA device registration.
> 
> Signed-off-by: Mika Westerberg <[email-masked]>
> ---
> Note that I'm not sure whether ep93xx_map_io() is the best place for calling
> clock init code. Alternative would be to put it in ep93xx_init_devices() just
> before calls to amba_device_register().

Thanks Mika,

I'm guessing none of the initcalls are early enough to solve this
problem? I think that calling from either ep93xx_map_io or
ep93xx_init_devices is fine, especially since this is a regression fix.

If nobody has a better solution:

Acked-by: Ryan Mallon <[email-masked]>

> Tested on ep9302 (ts-7260) and on ep9307 (Sim.One).
> 
>  arch/arm/mach-ep93xx/clock.c                 |    4 +---
>  arch/arm/mach-ep93xx/core.c                  |    1 +
>  arch/arm/mach-ep93xx/include/mach/platform.h |    1 +
>  3 files changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/arm/mach-ep93xx/clock.c b/arch/arm/mach-ep93xx/clock.c
> index 8bf3cec..119e614 100644
> --- a/arch/arm/mach-ep93xx/clock.c
> +++ b/arch/arm/mach-ep93xx/clock.c
> @@ -514,7 +514,7 @@ static void __init ep93xx_dma_clock_init(void)
>  	clk_m2m1.rate = clk_h.rate;
>  }
>  
> -static int __init ep93xx_clock_init(void)
> +void __init ep93xx_clock_init(void)
>  {
>  	u32 value;
>  
> @@ -558,6 +558,4 @@ static int __init ep93xx_clock_init(void)
>  		clk_p.rate / 1000000);
>  
>  	clkdev_add_table(clocks, ARRAY_SIZE(clocks));
> -	return 0;
>  }
> -arch_initcall(ep93xx_clock_init);
> diff --git a/arch/arm/mach-ep93xx/core.c b/arch/arm/mach-ep93xx/core.c
> index 4cb55d3..04e1b25 100644
> --- a/arch/arm/mach-ep93xx/core.c
> +++ b/arch/arm/mach-ep93xx/core.c
> @@ -65,6 +65,7 @@ static struct map_desc ep93xx_io_desc[] __initdata = {
>  void __init ep93xx_map_io(void)
>  {
>  	iotable_init(ep93xx_io_desc, ARRAY_SIZE(ep93xx_io_desc));
> +	ep93xx_clock_init();
>  }
>  
>  
> diff --git a/arch/arm/mach-ep93xx/include/mach/platform.h b/arch/arm/mach-ep93xx/include/mach/platform.h
> index 3330b36..9b732b1 100644
> --- a/arch/arm/mach-ep93xx/include/mach/platform.h
> +++ b/arch/arm/mach-ep93xx/include/mach/platform.h
> @@ -20,6 +20,7 @@ struct ep93xx_eth_data
>  
>  void ep93xx_map_io(void);
>  void ep93xx_init_irq(void);
> +void ep93xx_clock_init(void);
>  
>  /* EP93xx System Controller software locked register write */
>  void ep93xx_syscon_swlocked_write(unsigned int val, void __iomem *reg);

-- 
Bluewater Systems Ltd - ARM Technology Solution Centre

Ryan Mallon         		5 Amuri Park, 404 Barbadoes St
ryan at bluewatersys.com         	PO Box 13 889, Christchurch 8013
http://www.bluewatersys.com	New Zealand
Phone: +64 3 3779127		Freecall: Australia 1800 148 751
Fax:   +64 3 3779135			  USA 1800 261 2934