[PATCH net-next v4 06/27] net: pse-pd: tps23881: Add missing configuration register after disable

[Kory Maincent <kory.maincent@bootlin.com>]

From: Kory Maincent (Dent Project) <kory.maincent@bootlin.com>

When setting the PWOFF register, the controller resets multiple
configuration registers. This patch ensures these registers are
reconfigured as needed following a disable operation.

Acked-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
---

Change in v3:
- New patch
---
 drivers/net/pse-pd/tps23881.c | 30 +++++++++++++++++++++++++++++-
 1 file changed, 29 insertions(+), 1 deletion(-)

diff --git a/drivers/net/pse-pd/tps23881.c b/drivers/net/pse-pd/tps23881.c
index 4a75206b2de6..b87c391ae0f5 100644
--- a/drivers/net/pse-pd/tps23881.c
+++ b/drivers/net/pse-pd/tps23881.c
@@ -130,6 +130,7 @@ static int tps23881_pi_disable(struct pse_controller_dev *pcdev, int id)
 	struct i2c_client *client = priv->client;
 	u8 chan;
 	u16 val;
+	int ret;
 
 	if (id >= TPS23881_MAX_CHANS)
 		return -ERANGE;
@@ -143,7 +144,34 @@ static int tps23881_pi_disable(struct pse_controller_dev *pcdev, int id)
 				       BIT(chan % 4));
 	}
 
-	return i2c_smbus_write_word_data(client, TPS23881_REG_PW_EN, val);
+	ret = i2c_smbus_write_word_data(client, TPS23881_REG_PW_EN, val);
+	if (ret)
+		return ret;
+
+	/* PWOFF command resets lots of register which need to be
+	 * configured again. According to the datasheet "It may take upwards
+	 * of 5ms after PWOFFn command for all register values to be updated"
+	 */
+	mdelay(5);
+
+	/* Enable detection and classification */
+	ret = i2c_smbus_read_word_data(client, TPS23881_REG_DET_CLA_EN);
+	if (ret < 0)
+		return ret;
+
+	chan = priv->port[id].chan[0];
+	val = tps23881_set_val(ret, chan, 0, BIT(chan % 4), BIT(chan % 4));
+	val = tps23881_set_val(val, chan, 4, BIT(chan % 4), BIT(chan % 4));
+
+	if (priv->port[id].is_4p) {
+		chan = priv->port[id].chan[1];
+		val = tps23881_set_val(ret, chan, 0, BIT(chan % 4),
+				       BIT(chan % 4));
+		val = tps23881_set_val(val, chan, 4, BIT(chan % 4),
+				       BIT(chan % 4));
+	}
+
+	return i2c_smbus_write_word_data(client, TPS23881_REG_DET_CLA_EN, val);
 }
 
 static int tps23881_pi_is_enabled(struct pse_controller_dev *pcdev, int id)

-- 
2.34.1