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SubjectRe: [PATCH v2 3/3] usb: typec: tcpm: add get max power support
From
Hi Sebastian,

On 2023/3/21 4:31, Sebastian Reichel wrote:
> Hi,
>
> On Mon, Mar 20, 2023 at 06:07:11PM +0800, Frank Wang wrote:
>> Traverse fixed pdos to calculate the maximum power that the charger
>> can provide, and it can be get by POWER_SUPPLY_PROP_INPUT_POWER_LIMIT
>> property.
>>
>> Signed-off-by: Frank Wang <frank.wang@rock-chips.com>
>> ---
>> drivers/usb/typec/tcpm/tcpm.c | 24 ++++++++++++++++++++++++
>> 1 file changed, 24 insertions(+)
>>
>> diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
>> index 13830b5e2d09f..d6ad3cdf9e4af 100644
>> --- a/drivers/usb/typec/tcpm/tcpm.c
>> +++ b/drivers/usb/typec/tcpm/tcpm.c
>> @@ -6320,6 +6320,27 @@ static int tcpm_psy_get_current_now(struct tcpm_port *port,
>> return 0;
>> }
>>
>> +static int tcpm_psy_get_input_power_limit(struct tcpm_port *port,
>> + union power_supply_propval *val)
>> +{
>> + unsigned int src_mv, src_ma, max_src_mw = 0;
>> + unsigned int i, tmp;
>> +
>> + for (i = 0; i < port->nr_source_caps; i++) {
>> + u32 pdo = port->source_caps[i];
>> +
>> + if (pdo_type(pdo) == PDO_TYPE_FIXED) {
>> + src_mv = pdo_fixed_voltage(pdo);
>> + src_ma = pdo_max_current(pdo);
>> + tmp = src_mv * src_ma / 1000;
>> + max_src_mw = tmp > max_src_mw ? tmp : max_src_mw;
>> + }
>> + }
>> +
>> + val->intval = max_src_mw;
> The power-supply subsystem expects Microwatts and not Milliwatts.

Yes, but I see the 'power_supply_propval' member 'intval' is an integer
type, I worry about it may be overflowed that uses Microwatts.


BR.
Frank

> -- Sebastian
>
>> + return 0;
>> +}
>> +
>> static int tcpm_psy_get_prop(struct power_supply *psy,
>> enum power_supply_property psp,
>> union power_supply_propval *val)
>> @@ -6349,6 +6370,9 @@ static int tcpm_psy_get_prop(struct power_supply *psy,
>> case POWER_SUPPLY_PROP_CURRENT_NOW:
>> ret = tcpm_psy_get_current_now(port, val);
>> break;
>> + case POWER_SUPPLY_PROP_INPUT_POWER_LIMIT:
>> + tcpm_psy_get_input_power_limit(port, val);
>> + break;
>> default:
>> ret = -EINVAL;
>> break;
>> --
>> 2.17.1
>>

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