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From:   Chen-Yu Tsai <wenst@chromium.org>
To:     Sebastian Reichel <sre@kernel.org>
Cc:     Chen-Yu Tsai <wenst@chromium.org>, linux-pm@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: [PATCH] power: supply: core: Avoid duplicate hwmon device from thermal framework
Date:   Tue, 13 Jun 2023 17:07:23 +0800
Message-ID: <20230613090726.1358199-1-wenst@chromium.org>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

When the power supply device being registered supports a temperature
readout, the core registers a thermal zone for it. The thermal core
would register a hwmon device for that unless told otherwise.

When CONFIG_POWER_SUPPLY_HWMON is enabled, the power supply core creates
a hwmon device. This results in a second entry, one which has a better
name than the one registered through the thermal framework. It could
potentially have readouts other than temperature.

To simplify the result, tell the thermal framework to not register a
hwmon device if CONFIG_POWER_SUPPLY_HWMON is enabled. The result is
one hwmon device with all the readings the device supports.

Signed-off-by: Chen-Yu Tsai <wenst@chromium.org>
---
 drivers/power/supply/power_supply_core.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/power/supply/power_supply_core.c b/drivers/power/supply/power_supply_core.c
index 3791aec69ddc..4aa466c945e2 100644
--- a/drivers/power/supply/power_supply_core.c
+++ b/drivers/power/supply/power_supply_core.c
@@ -1305,8 +1305,12 @@ static int psy_register_thermal(struct power_supply *psy)
 
 	/* Register battery zone device psy reports temperature */
 	if (psy_has_property(psy->desc, POWER_SUPPLY_PROP_TEMP)) {
+		/* Prefer our hwmon device and avoid duplicates */
+		struct thermal_zone_params tzp = {
+			.no_hwmon = IS_ENABLED(CONFIG_POWER_SUPPLY_HWMON)
+		};
 		psy->tzd = thermal_zone_device_register(psy->desc->name,
-				0, 0, psy, &psy_tzd_ops, NULL, 0, 0);
+				0, 0, psy, &psy_tzd_ops, &tzp, 0, 0);
 		if (IS_ERR(psy->tzd))
 			return PTR_ERR(psy->tzd);
 		ret = thermal_zone_device_enable(psy->tzd);
-- 
2.41.0.162.gfafddb0af9-goog