Re: [PATCH 1/5] i2c: core: Pick i2c bus number from ACPI if present

[Jinyang He <hejinyang@loongson.cn>]

On 2022/9/22 下午7:39, Binbin Zhou wrote:

> Under LoongARCH based on ACPI(such as Loongson-3A + LS7A), the ls2x i2c
> driver obtains the i2c bus number from ACPI table.
>
> Similar to the DT-base system, this is also a static bus number.
>
> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
> Signed-off-by: Binbin Zhou <zhoubinbin@loongson.cn>
> ---
>   drivers/i2c/i2c-core-base.c | 10 +++++++++-
>   1 file changed, 9 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
> index 91007558bcb2..ffab4cc2c6ba 100644
> --- a/drivers/i2c/i2c-core-base.c
> +++ b/drivers/i2c/i2c-core-base.c
> @@ -1559,7 +1559,8 @@ static int __i2c_add_numbered_adapter(struct i2c_adapter *adap)
>   int i2c_add_adapter(struct i2c_adapter *adapter)
>   {
>   	struct device *dev = &adapter->dev;
> -	int id;
> +	acpi_status status;
> +	unsigned long long id;
>   
>   	if (dev->of_node) {
>   		id = of_alias_get_id(dev->of_node, "i2c");
> @@ -1567,6 +1568,13 @@ int i2c_add_adapter(struct i2c_adapter *adapter)
>   			adapter->nr = id;
>   			return __i2c_add_numbered_adapter(adapter);
>   		}
> +	} else if (dev->parent->fwnode) {
> +		status = acpi_evaluate_integer(ACPI_HANDLE(dev->parent),
> +						"_UID", NULL, &id);
> +		if (ACPI_SUCCESS(status) && (id >= 0)) {

Hi, Binbin,


Emm, the id is unsigned and it always return true if (id>=0). And I think

you should check the other patches.


Jinyang


> +			adapter->nr = id;
> +			return __i2c_add_numbered_adapter(adapter);
> +		}
>   	}
>   
>   	mutex_lock(&core_lock);