Re: [v4,2/2] usb: typec: tcpm: add get max power support

From: Guenter Roeck
Date: Fri Jun 16 2023 - 04:37:03 EST


On 6/16/23 00:52, 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@xxxxxxxxxxxxxx>

Reviewed-by: Guenter Roeck <linux@xxxxxxxxxxxx>

---
Changelog:
v4:
- No change

v3:
- Use Microwatts instead of Milliwatts to follow the ABI, commented by Sebastian Reichel.

v2:
- No change

v1:
- https://patchwork.kernel.org/project/linux-usb/patch/20230313025843.17162-4-frank.wang@xxxxxxxxxxxxxx/

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 9f6aaa3e70ca8..829d75ebab422 100644
--- a/drivers/usb/typec/tcpm/tcpm.c
+++ b/drivers/usb/typec/tcpm/tcpm.c
@@ -6340,6 +6340,27 @@ 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_uw = 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;
+ max_src_uw = tmp > max_src_uw ? tmp : max_src_uw;
+ }
+ }
+
+ val->intval = max_src_uw;
+ return 0;
+}
+
static int tcpm_psy_get_prop(struct power_supply *psy,
enum power_supply_property psp,
union power_supply_propval *val)
@@ -6369,6 +6390,9 @@ 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;