power: supply: axp20x_usb_power: fix race condition with usb bc

When input_current_limit is set while USB BC is in progress, the BC
module will overwrite the value that was set when it finishes detection.

Signed-off-by: Aren Moynihan <aren@peacevolution.org>
Link: https://lore.kernel.org/r/20240130203714.3020464-4-aren@peacevolution.org
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

diff --git a/drivers/power/supply/axp20x_usb_power.c b/drivers/power/supply/axp20x_usb_power.c
index 923121b23d5fd37079187902caa2142db10cf7fb..ac5a3f126df6921160d2c97fea92e25ad354f4ee 100644 (file)
--- a/drivers/power/supply/axp20x_usb_power.c
+++ b/drivers/power/supply/axp20x_usb_power.c
@@ -117,6 +117,15 @@ static void axp20x_usb_power_poll_vbus(struct work_struct *work)
        if (val != power->old_status)
                power_supply_changed(power->supply);
 
+       if (power->usb_bc_en_bit && (val & AXP20X_PWR_STATUS_VBUS_PRESENT) !=
+               (power->old_status & AXP20X_PWR_STATUS_VBUS_PRESENT)) {
+               dev_dbg(power->dev, "Cable status changed, re-enabling USB BC");
+               ret = regmap_field_write(power->usb_bc_en_bit, 1);
+               if (ret)
+                       dev_err(power->dev, "failed to enable USB BC: errno %d",
+                               ret);
+       }
+
        power->old_status = val;
        power->online = val & AXP20X_PWR_STATUS_VBUS_USED;
 
@@ -265,12 +274,26 @@ static int axp20x_usb_power_set_voltage_min(struct axp20x_usb_power *power,
 static int axp20x_usb_power_set_input_current_limit(struct axp20x_usb_power *power,
                                                    int intval)
 {
+       int ret;
        unsigned int reg;
        const unsigned int max = power->axp_data->curr_lim_table_size;
 
        if (intval == -1)
                return -EINVAL;
 
+       /*
+        * BC1.2 detection can cause a race condition if we try to set a current
+        * limit while it's in progress. When it finishes it will overwrite the
+        * current limit we just set.
+        */
+       if (power->usb_bc_en_bit) {
+               dev_dbg(power->dev,
+                       "disabling BC1.2 detection because current limit was set");
+               ret = regmap_field_write(power->usb_bc_en_bit, 0);
+               if (ret)
+                       return ret;
+       }
+
        for (reg = max - 1; reg > 0; reg--)
                if (power->axp_data->curr_lim_table[reg] <= intval)
                        break;