Re: [PATCH 1/9] clk: sunxi: Give sunxi_factors_register a registers parameter

[Hans de Goede <hdegoede-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>]

Hi,

On 11/21/2014 09:35 AM, Maxime Ripard wrote:
> Hi Hans,
> 
> On Thu, Nov 20, 2014 at 04:55:20PM +0100, Hans de Goede wrote:
>> Before this commit sunxi_factors_register uses of_iomap(node, 0) to get
>> the clk registers. The sun6i prcm has factor clocks, for which we want to
>> use sunxi_factors_register, but of_iomap(node, 0) does not work for the prcm
>> factor clocks, because the prcm uses the mfd framework, so the registers
>> are not part of the dt-node, instead they are added to the platform_device,
>> as platform_device resources.
>>
>> This commit makes getting the registers the callers duty, so that
>> sunxi_factors_register can be used with mfd instantiated platform device too.
>>
>> Signed-off-by: Hans de Goede <hdegoede-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
> 
> Funny, I was thinking of doing exactly the same thing for MMC clocks :)
> 
>> ---
>>  drivers/clk/sunxi/clk-factors.c    | 10 ++++------
>>  drivers/clk/sunxi/clk-factors.h    |  7 ++++---
>>  drivers/clk/sunxi/clk-mod0.c       |  6 ++++--
>>  drivers/clk/sunxi/clk-sun8i-mbus.c |  2 +-
>>  drivers/clk/sunxi/clk-sunxi.c      |  3 ++-
>>  5 files changed, 15 insertions(+), 13 deletions(-)
>>
>> diff --git a/drivers/clk/sunxi/clk-factors.c b/drivers/clk/sunxi/clk-factors.c
>> index f83ba09..fc4f4b5 100644
>> --- a/drivers/clk/sunxi/clk-factors.c
>> +++ b/drivers/clk/sunxi/clk-factors.c
>> @@ -156,9 +156,10 @@ static const struct clk_ops clk_factors_ops = {
>>  	.set_rate = clk_factors_set_rate,
>>  };
>>  
>> -struct clk * __init sunxi_factors_register(struct device_node *node,
>> -					   const struct factors_data *data,
>> -					   spinlock_t *lock)
>> +struct clk *sunxi_factors_register(struct device_node *node,
>> +				   const struct factors_data *data,
>> +				   spinlock_t *lock,
>> +				   void __iomem *reg)
>>  {
>>  	struct clk *clk;
>>  	struct clk_factors *factors;
>> @@ -168,11 +169,8 @@ struct clk * __init sunxi_factors_register(struct device_node *node,
>>  	struct clk_hw *mux_hw = NULL;
>>  	const char *clk_name = node->name;
>>  	const char *parents[FACTORS_MAX_PARENTS];
>> -	void __iomem *reg;
>>  	int i = 0;
>>  
>> -	reg = of_iomap(node, 0);
>> -
>>  	/* if we have a mux, we will have >1 parents */
>>  	while (i < FACTORS_MAX_PARENTS &&
>>  	       (parents[i] = of_clk_get_parent_name(node, i)) != NULL)
>> diff --git a/drivers/clk/sunxi/clk-factors.h b/drivers/clk/sunxi/clk-factors.h
>> index 9913840..1f5526d 100644
>> --- a/drivers/clk/sunxi/clk-factors.h
>> +++ b/drivers/clk/sunxi/clk-factors.h
>> @@ -37,8 +37,9 @@ struct clk_factors {
>>  	spinlock_t *lock;
>>  };
>>  
>> -struct clk * __init sunxi_factors_register(struct device_node *node,
>> -					   const struct factors_data *data,
>> -					   spinlock_t *lock);
>> +struct clk *sunxi_factors_register(struct device_node *node,
>> +				   const struct factors_data *data,
>> +				   spinlock_t *lock,
>> +				   void __iomem *reg);
> 
> Why are you dropping the __init there?

Because it is going to be used from mfd instantiation, so from a platform_dev
probe function which is not __init.

> 
>>  
>>  #endif
>> diff --git a/drivers/clk/sunxi/clk-mod0.c b/drivers/clk/sunxi/clk-mod0.c
>> index 4a56385..9530833 100644
>> --- a/drivers/clk/sunxi/clk-mod0.c
>> +++ b/drivers/clk/sunxi/clk-mod0.c
>> @@ -78,7 +78,8 @@ static DEFINE_SPINLOCK(sun4i_a10_mod0_lock);
>>  
>>  static void __init sun4i_a10_mod0_setup(struct device_node *node)
>>  {
>> -	sunxi_factors_register(node, &sun4i_a10_mod0_data, &sun4i_a10_mod0_lock);
>> +	sunxi_factors_register(node, &sun4i_a10_mod0_data,
>> +			       &sun4i_a10_mod0_lock, of_iomap(node, 0));
> 
> As of_iomap can fail, I'd rather check the returned value before
> calling sunxi_factors_register.
> 
> I know it wasn't done before, but it's the right thing to do, as it
> would lead to an instant crash if that fails.

Ok, I'll wait for you to review the rest of the series and then do a v2 of the
patch-set with this fixed (as time permits).

Regards,

Hans