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From:   Kai-Heng Feng <kai.heng.feng@canonical.com>
To:     ktsai@capellamicro.com, jic23@kernel.org, lars@metafoo.de
Cc:     hdegoede@redhat.com, Kai-Heng Feng <kai.heng.feng@canonical.com>,
        Wahaj <wahajaved@protonmail.com>, linux-iio@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: [PATCH] iio: light: cm32181: Fix PM support on system with 2 I2C resources
Date:   Wed, 18 Jan 2023 00:09:51 +0800
Message-Id: <20230117160951.282581-1-kai.heng.feng@canonical.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

Commit c1e62062ff54 ("iio: light: cm32181: Handle CM3218 ACPI devices
with 2 I2C resources") creates a second client for the actual I2C
address, but the "struct device" passed to PM ops is the first client
that can't talk to the sensor.

That means the I2C transfers in both suspend and resume routines can
fail and blocking the whole suspend process.

Instead of using the first client for I2C transfer, store the cm32181
private struct on both cases so the PM ops can get the correct I2C
client to perfrom suspend and resume.

Fixes: 68c1b3dd5c48 ("iio: light: cm32181: Add PM support")
Tested-by: Wahaj <wahajaved@protonmail.com>
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
---
 drivers/iio/light/cm32181.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/drivers/iio/light/cm32181.c b/drivers/iio/light/cm32181.c
index 001055d097509..0f319c891353c 100644
--- a/drivers/iio/light/cm32181.c
+++ b/drivers/iio/light/cm32181.c
@@ -440,6 +440,8 @@ static int cm32181_probe(struct i2c_client *client)
 	if (!indio_dev)
 		return -ENOMEM;
 
+	i2c_set_clientdata(client, indio_dev);
+
 	/*
 	 * Some ACPI systems list 2 I2C resources for the CM3218 sensor, the
 	 * SMBus Alert Response Address (ARA, 0x0c) and the actual I2C address.
@@ -458,9 +460,9 @@ static int cm32181_probe(struct i2c_client *client)
 		client = i2c_acpi_new_device(dev, 1, &board_info);
 		if (IS_ERR(client))
 			return PTR_ERR(client);
-	}
 
-	i2c_set_clientdata(client, indio_dev);
+		i2c_set_clientdata(client, indio_dev);
+	}
 
 	cm32181 = iio_priv(indio_dev);
 	cm32181->client = client;
@@ -490,7 +492,8 @@ static int cm32181_probe(struct i2c_client *client)
 
 static int cm32181_suspend(struct device *dev)
 {
-	struct i2c_client *client = to_i2c_client(dev);
+	struct cm32181_chip *cm32181 = iio_priv(dev_get_drvdata(dev));
+	struct i2c_client *client = cm32181->client;
 
 	return i2c_smbus_write_word_data(client, CM32181_REG_ADDR_CMD,
 					 CM32181_CMD_ALS_DISABLE);
@@ -498,8 +501,8 @@ static int cm32181_suspend(struct device *dev)
 
 static int cm32181_resume(struct device *dev)
 {
-	struct i2c_client *client = to_i2c_client(dev);
 	struct cm32181_chip *cm32181 = iio_priv(dev_get_drvdata(dev));
+	struct i2c_client *client = cm32181->client;
 
 	return i2c_smbus_write_word_data(client, CM32181_REG_ADDR_CMD,
 					 cm32181->conf_regs[CM32181_REG_ADDR_CMD]);
-- 
2.34.1