power: supply: axp288-charger: Set Vhold to 4.4V

The AXP288's recommended and factory default Vhold value (minimum
input voltage below which the input current draw will be reduced)
is 4.4V. This lines up with other charger IC's such as the TI
bq2419x/bq2429x series which use 4.36V or 4.44V.

For some reason some BIOS-es initialize Vhold to 4.6V or even 4.7V
which combined with the typical voltage drop over typically low
wire gauge micro-USB cables leads to the input-current getting
capped below 1A (with a 2A capable dedicated charger) based on Vhold.

This leads to slow charging, or even to the device slowly discharging
if the device is in heavy use.

As the Linux AXP288 drivers use the builtin BC1.2 charger detection
and send the input-current-limit according to the detected charger
there really is no reason not to use the recommended 4.4V Vhold.

Set Vhold to 4.4V to fix the slow charging issue on various devices.

There is one exception, the special-case of the HP X2 2-in-1s which
combine this BC1.2 capable PMIC with a Type-C port and a 5V/3A factory
provided charger with a Type-C plug which does not do BC1.2. These
have their input-current-limit hardcoded to 3A (like under Windows)
and use a higher Vhold on purpose to limit the current when used
with other chargers. To avoid touching Vhold on these HP X2 laptops
the code setting Vhold is added to an else branch of the if checking
for these models.

Note this also fixes the sofar unused VBUS_ISPOUT_VHOLD_SET_MASK
define, which was wrong.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

diff --git a/drivers/power/supply/axp288_charger.c b/drivers/power/supply/axp288_charger.c
index ec41f6cd3f93fb323e4975fc9481036fa80e00c8..c498e62ab4e2058b0b019336698235a4b23fcda8 100644 (file)
--- a/drivers/power/supply/axp288_charger.c
+++ b/drivers/power/supply/axp288_charger.c
@@ -42,11 +42,11 @@
 #define VBUS_ISPOUT_CUR_LIM_1500MA     0x1     /* 1500mA */
 #define VBUS_ISPOUT_CUR_LIM_2000MA     0x2     /* 2000mA */
 #define VBUS_ISPOUT_CUR_NO_LIM         0x3     /* 2500mA */
-#define VBUS_ISPOUT_VHOLD_SET_MASK     0x31
+#define VBUS_ISPOUT_VHOLD_SET_MASK     0x38
 #define VBUS_ISPOUT_VHOLD_SET_BIT_POS  0x3
 #define VBUS_ISPOUT_VHOLD_SET_OFFSET   4000    /* 4000mV */
 #define VBUS_ISPOUT_VHOLD_SET_LSB_RES  100     /* 100mV */
-#define VBUS_ISPOUT_VHOLD_SET_4300MV   0x3     /* 4300mV */
+#define VBUS_ISPOUT_VHOLD_SET_4400MV   0x4     /* 4400mV */
 #define VBUS_ISPOUT_VBUS_PATH_DIS      BIT(7)
 
 #define CHRG_CCCV_CC_MASK              0xf             /* 4 bits */
@@ -769,6 +769,16 @@ static int charger_init_hw_regs(struct axp288_chrg_info *info)
                ret = axp288_charger_vbus_path_select(info, true);
                if (ret < 0)
                        return ret;
+       } else {
+               /* Set Vhold to the factory default / recommended 4.4V */
+               val = VBUS_ISPOUT_VHOLD_SET_4400MV << VBUS_ISPOUT_VHOLD_SET_BIT_POS;
+               ret = regmap_update_bits(info->regmap, AXP20X_VBUS_IPSOUT_MGMT,
+                                        VBUS_ISPOUT_VHOLD_SET_MASK, val);
+               if (ret < 0) {
+                       dev_err(&info->pdev->dev, "register(%x) write error(%d)\n",
+                               AXP20X_VBUS_IPSOUT_MGMT, ret);
+                       return ret;
+               }
        }
 
        /* Read current charge voltage and current limit */