power: supply: bq25890: Add support to read back the settings from the chip

On most x86/ACPI devices there is no devicetree to supply the necessary
init-data. Instead the firmware already fully initializes the bq25890
charger at boot. To support this, add support for reading back the
settings from the chip through a new "linux,read-back-settings" boolean.

So far this new property is only used on x86/ACPI (non devicetree) devs,
IOW it is not used in actual devicetree files. The devicetree-bindings
maintainers have requested properties like these to not be added to the
devicetree-bindings, so the new property is deliberately not added
to the existing devicetree-bindings.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

diff --git a/drivers/power/supply/bq25890_charger.c b/drivers/power/supply/bq25890_charger.c
index cd80d74..f758e28 100644 (file)
--- a/drivers/power/supply/bq25890_charger.c
+++ b/drivers/power/supply/bq25890_charger.c
@@ -111,6 +111,7 @@ struct bq25890_device {
        struct regmap_field *rmap_fields[F_MAX_FIELDS];
 
        bool skip_reset;
+       bool read_back_init_data;
        enum bq25890_chip_version chip_version;
        struct bq25890_init_data init_data;
        struct bq25890_state state;
@@ -696,7 +697,7 @@ static int bq25890_chip_reset(struct bq25890_device *bq)
 
 static int bq25890_rw_init_data(struct bq25890_device *bq)
 {
-       bool write = true;
+       bool write = !bq->read_back_init_data;
        int ret;
        int i;
 
@@ -981,6 +982,10 @@ static int bq25890_fw_probe(struct bq25890_device *bq)
        struct bq25890_init_data *init = &bq->init_data;
 
        bq->skip_reset = device_property_read_bool(bq->dev, "linux,skip-reset");
+       bq->read_back_init_data = device_property_read_bool(bq->dev,
+                                               "linux,read-back-settings");
+       if (bq->read_back_init_data)
+               return 0;
 
        ret = bq25890_fw_read_u32_props(bq);
        if (ret < 0)