From 95b22bd6dcf198340b0c40a906a463064c215b0c Mon Sep 17 00:00:00 2001
From: Conor Dooley <conor.dooley@microchip.com>
Date: Wed, 26 Oct 2022 08:49:18 +0100
Subject: [PATCH] i2c: microchip: fix ack sending logic
"Master receive mode" was not correctly sending ACKs/NACKs in the
interrupt handler. Bring the handling of M_SLAR_ACK, M_RX_DATA_ACKED &
M_RX_DATA_NACKED in line with the Linux driver.
Fixes: 0dc0d1e094 ("i2c: Add Microchip PolarFire SoC I2C driver")
Reported-by: Shravan Chippa <shravan.chippa@microchip.com>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Padmarao Begari <padmarao.begari@microchip.com>
Reviewed-by: Heiko Schocher <hs@denx.de>
---
drivers/i2c/i2c-microchip.c | 23 +++++++++++++++++------
1 file changed, 17 insertions(+), 6 deletions(-)
diff --git a/drivers/i2c/i2c-microchip.c b/drivers/i2c/i2c-microchip.c
index 12f65d0af7..3a27459386 100644
--- a/drivers/i2c/i2c-microchip.c
+++ b/drivers/i2c/i2c-microchip.c
@@ -2,8 +2,9 @@
/*
* Microchip I2C controller driver
*
- * Copyright (C) 2021 Microchip Technology Inc.
+ * Copyright (C) 2021-2022 Microchip Technology Inc.
* Padmarao Begari <padmarao.begari@microchip.com>
+ * Conor Dooley <conor.dooley@microchip.com>
*/
#include <common.h>
#include <clk.h>
@@ -265,16 +266,27 @@ static int mpfs_i2c_service_handler(struct mpfs_i2c_bus *bus)
}
break;
case STATUS_M_SLAR_ACK:
- ctrl = readl(bus->base + MPFS_I2C_CTRL);
- ctrl |= CTRL_AA;
- writel(ctrl, bus->base + MPFS_I2C_CTRL);
- if (bus->msg_len == 0) {
+ if (bus->msg_len > 1u) {
+ ctrl = readl(bus->base + MPFS_I2C_CTRL);
+ ctrl |= CTRL_AA;
+ writel(ctrl, bus->base + MPFS_I2C_CTRL);
+ } else if (bus->msg_len == 1u) {
+ ctrl = readl(bus->base + MPFS_I2C_CTRL);
+ ctrl &= ~CTRL_AA;
+ writel(ctrl, bus->base + MPFS_I2C_CTRL);
+ } else {
+ ctrl = readl(bus->base + MPFS_I2C_CTRL);
+ ctrl |= CTRL_AA;
+ writel(ctrl, bus->base + MPFS_I2C_CTRL);
/* On the last byte to be transmitted, send STOP */
mpfs_i2c_stop(bus);
finish = true;
}
break;
case STATUS_M_RX_DATA_ACKED:
+ mpfs_i2c_empty_rx(bus);
+ break;
+ case STATUS_M_RX_DATA_NACKED:
mpfs_i2c_empty_rx(bus);
if (bus->msg_len == 0) {
/* On the last byte to be transmitted, send STOP */
@@ -283,7 +295,6 @@ static int mpfs_i2c_service_handler(struct mpfs_i2c_bus *bus)
}
break;
case STATUS_M_TX_DATA_NACK:
- case STATUS_M_RX_DATA_NACKED:
case STATUS_M_SLAR_NACK:
case STATUS_M_SLAW_NACK:
bus->msg_err = -ENXIO;
--
2.39.5