From 76047c0312414915035f4ebbaa533fe3817a21e0 Mon Sep 17 00:00:00 2001
From: Daniel Baumann <daniel.baumann@progress-linux.org>
Date: Mon, 3 Jun 2024 07:08:49 +0200
Subject: Adding upstream version 6.8.12.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
---
 drivers/net/dsa/mv88e6xxx/global1.c | 89 +++++++++++++++++++++++++++++++++++++
 1 file changed, 89 insertions(+)

(limited to 'drivers/net/dsa/mv88e6xxx/global1.c')

diff --git a/drivers/net/dsa/mv88e6xxx/global1.c b/drivers/net/dsa/mv88e6xxx/global1.c
index 49444a72ff..9820cd5967 100644
--- a/drivers/net/dsa/mv88e6xxx/global1.c
+++ b/drivers/net/dsa/mv88e6xxx/global1.c
@@ -75,6 +75,95 @@ static int mv88e6xxx_g1_wait_init_ready(struct mv88e6xxx_chip *chip)
 	return mv88e6xxx_g1_wait_bit(chip, MV88E6XXX_G1_STS, bit, 1);
 }
 
+static int mv88e6250_g1_eeprom_reload(struct mv88e6xxx_chip *chip)
+{
+	/* MV88E6185_G1_CTL1_RELOAD_EEPROM is also valid for 88E6250 */
+	int bit = __bf_shf(MV88E6185_G1_CTL1_RELOAD_EEPROM);
+	u16 val;
+	int err;
+
+	err = mv88e6xxx_g1_read(chip, MV88E6XXX_G1_CTL1, &val);
+	if (err)
+		return err;
+
+	val |= MV88E6185_G1_CTL1_RELOAD_EEPROM;
+
+	err = mv88e6xxx_g1_write(chip, MV88E6XXX_G1_CTL1, val);
+	if (err)
+		return err;
+
+	return mv88e6xxx_g1_wait_bit(chip, MV88E6XXX_G1_CTL1, bit, 0);
+}
+
+/* Returns 0 when done, -EBUSY when waiting, other negative codes on error */
+static int mv88e6xxx_g1_is_eeprom_done(struct mv88e6xxx_chip *chip)
+{
+	u16 val;
+	int err;
+
+	err = mv88e6xxx_g1_read(chip, MV88E6XXX_G1_STS, &val);
+	if (err < 0) {
+		dev_err(chip->dev, "Error reading status");
+		return err;
+	}
+
+	/* If the switch is still resetting, it may not
+	 * respond on the bus, and so MDIO read returns
+	 * 0xffff. Differentiate between that, and waiting for
+	 * the EEPROM to be done by bit 0 being set.
+	 */
+	if (val == 0xffff || !(val & BIT(MV88E6XXX_G1_STS_IRQ_EEPROM_DONE)))
+		return -EBUSY;
+
+	return 0;
+}
+
+/* As the EEInt (EEPROM done) flag clears on read if the status register, this
+ * function must be called directly after a hard reset or EEPROM ReLoad request,
+ * or the done condition may have been missed
+ */
+int mv88e6xxx_g1_wait_eeprom_done(struct mv88e6xxx_chip *chip)
+{
+	const unsigned long timeout = jiffies + 1 * HZ;
+	int ret;
+
+	/* Wait up to 1 second for the switch to finish reading the
+	 * EEPROM.
+	 */
+	while (time_before(jiffies, timeout)) {
+		ret = mv88e6xxx_g1_is_eeprom_done(chip);
+		if (ret != -EBUSY)
+			return ret;
+	}
+
+	dev_err(chip->dev, "Timeout waiting for EEPROM done");
+	return -ETIMEDOUT;
+}
+
+int mv88e6250_g1_wait_eeprom_done_prereset(struct mv88e6xxx_chip *chip)
+{
+	int ret;
+
+	ret = mv88e6xxx_g1_is_eeprom_done(chip);
+	if (ret != -EBUSY)
+		return ret;
+
+	/* Pre-reset, we don't know the state of the switch - when
+	 * mv88e6xxx_g1_is_eeprom_done() returns -EBUSY, that may be because
+	 * the switch is actually busy reading the EEPROM, or because
+	 * MV88E6XXX_G1_STS_IRQ_EEPROM_DONE has been cleared by an unrelated
+	 * status register read already.
+	 *
+	 * To account for the latter case, trigger another EEPROM reload for
+	 * another chance at seeing the done flag.
+	 */
+	ret = mv88e6250_g1_eeprom_reload(chip);
+	if (ret)
+		return ret;
+
+	return mv88e6xxx_g1_wait_eeprom_done(chip);
+}
+
 /* Offset 0x01: Switch MAC Address Register Bytes 0 & 1
  * Offset 0x02: Switch MAC Address Register Bytes 2 & 3
  * Offset 0x03: Switch MAC Address Register Bytes 4 & 5
-- 
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