[PATCH v2 09/12] clk: boston: Allow to get regmap from parent device

[Jiaxun Yang]

在2024年5月16日五月 下午3:00，Jonas Karlman写道：
> Hi Jiaxun,
>
> On 2024-05-16 13:40, Jiaxun Yang wrote:
>> In upstream devicetree, clk_boston is a child of syscon node
>> and there is no "regmap" property for clk_boston node.
>> 
>> Try to check parent device first to look for syscon.
>> 
>> Signed-off-by: Jiaxun Yang <jiaxun.yang at flygoat.com>
>> ---
>> v2: Move syscon_get_regmap to probe
>> ---
>>  drivers/clk/clk_boston.c | 37 +++++++++++++++++++++++++------------
>>  1 file changed, 25 insertions(+), 12 deletions(-)
>> 
>> diff --git a/drivers/clk/clk_boston.c b/drivers/clk/clk_boston.c
>> index 030ff7cc58ec..1985bb0ec334 100644
>> --- a/drivers/clk/clk_boston.c
>> +++ b/drivers/clk/clk_boston.c
>> @@ -12,6 +12,7 @@
>>  #include <linux/printk.h>
>>  
>>  struct clk_boston {
>> +	struct udevice *syscon;
>>  	struct regmap *regmap;
>>  };
>>  
>> @@ -58,23 +59,33 @@ const struct clk_ops clk_boston_ops = {
>>  	.get_rate = clk_boston_get_rate,
>>  };
>>  
>> -static int clk_boston_of_to_plat(struct udevice *dev)
>> +static int clk_boston_probe(struct udevice *dev)
>>  {
>>  	struct clk_boston *state = dev_get_plat(dev);
>> -	struct udevice *syscon;
>> -	int err;
>>  
>> -	err = uclass_get_device_by_phandle(UCLASS_SYSCON, dev,
>> -					   "regmap", &syscon);
>> -	if (err) {
>> -		pr_err("unable to find syscon device\n");
>> -		return err;
>> +	state->regmap = syscon_get_regmap(state->syscon);
>> +	if (IS_ERR(state->regmap)) {
>> +		pr_err("unable to find regmap\n");
>> +		return PTR_ERR(state->regmap);
>>  	}
>>  
>> -	state->regmap = syscon_get_regmap(syscon);
>> -	if (!state->regmap) {
>> -		pr_err("unable to find regmap\n");
>> -		return -ENODEV;
>> +	return 0;
>> +}
>> +
>> +static int clk_boston_of_to_plat(struct udevice *dev)
>> +{
>> +	struct clk_boston *state = dev_get_plat(dev);
>> +	int err;
>> +
>> +	if (dev->parent && device_get_uclass_id(dev->parent) == UCLASS_SYSCON) {
>> +		state->syscon = dev->parent;
>> +	} else {
>> +		err = uclass_get_device_by_phandle(UCLASS_SYSCON, dev,
>> +						   "regmap", &state->syscon);
>
> This will trigger a probe of the referenced regmap phandle. To simplify
> and avoid probing devices at of_to_plat() stage, you can probably just
> rename of_to_plat() to probe() and skip of_to_plat() stage completely.

Thanks, will fix in next version.

>
> Regards,
> Jonas

-- 
- Jiaxun