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From:   Chen-Yu Tsai <wenst@chromium.org>
To:     Matthias Brugger <matthias.bgg@gmail.com>,
        AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@collabora.com>,
        Mark Brown <broonie@kernel.org>
Cc:     Chen-Yu Tsai <wenst@chromium.org>,
        Zhiyong Tao <zhiyong.tao@mediatek.com>,
        linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-mediatek@lists.infradead.org
Subject: [PATCH] regulator: mt6358: return error for get/set mode op on linear range LDO
Date:   Tue, 19 Sep 2023 16:36:46 +0800
Message-ID: <20230919083647.3909889-1-wenst@chromium.org>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

The buck and linear range (VSRAM_*) regulators share one set of ops.
This set includes support for get/set mode. However this only makes
sense for buck regulators, not LDOs. The callbacks were not checking
whether the register offset and/or mask for mode setting was valid or
not. This ends up making the kernel report "normal" mode operation for
the LDOs.

Instead, make the callbacks return -EINVAL if the mode register mask is
not set, signaling that it is not supported.

Fixes: f67ff1bd58f0 ("regulator: mt6358: Add support for MT6358 regulator")
Signed-off-by: Chen-Yu Tsai <wenst@chromium.org>
---
 drivers/regulator/mt6358-regulator.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/regulator/mt6358-regulator.c b/drivers/regulator/mt6358-regulator.c
index b9cda2210c33..120c60d40ed4 100644
--- a/drivers/regulator/mt6358-regulator.c
+++ b/drivers/regulator/mt6358-regulator.c
@@ -408,6 +408,9 @@ static int mt6358_regulator_set_mode(struct regulator_dev *rdev,
 	const struct mt6358_regulator_info *info = to_regulator_info(rdev->desc);
 	int val;
 
+	if (!info->modeset_mask)
+		return -EINVAL;
+
 	switch (mode) {
 	case REGULATOR_MODE_FAST:
 		val = MT6358_BUCK_MODE_FORCE_PWM;
@@ -433,6 +436,9 @@ static unsigned int mt6358_regulator_get_mode(struct regulator_dev *rdev)
 	const struct mt6358_regulator_info *info = to_regulator_info(rdev->desc);
 	int ret, regval;
 
+	if (!info->modeset_mask)
+		return -EINVAL;
+
 	ret = regmap_read(rdev->regmap, info->modeset_reg, &regval);
 	if (ret != 0) {
 		dev_err(&rdev->dev,
-- 
2.42.0.459.ge4e396fd5e-goog