From ccea46c05b08b34ef829d460e50e2ce9bc17cdc7 Mon Sep 17 00:00:00 2001 From: Stefan Roese Date: Thu, 18 Nov 2021 09:18:41 +0100 Subject: [PATCH] i2c: mvtwsi: Swab the register address if its size is > 1 MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Testing on Armada XP with an EEPROM using register address with size of 2 has shown, that the register address bytes are sent to the I2C EEPROM in the incorrect order. This patch swabs the address bytes so that the correct address is transferred to the I2C device. BTW: This worked without any issues before migrating Armada XP to DM I2C. Signed-off-by: Stefan Roese Cc: Heiko Schocher Cc: Samuel Holland Cc: Baruch Siach Cc: Pali Rohár Cc: Marek Behún Tested-by: Marek Behún --- drivers/i2c/mvtwsi.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/drivers/i2c/mvtwsi.c b/drivers/i2c/mvtwsi.c index 236bfb8..ff21e3c 100644 --- a/drivers/i2c/mvtwsi.c +++ b/drivers/i2c/mvtwsi.c @@ -860,6 +860,9 @@ static int mvtwsi_i2c_xfer(struct udevice *bus, struct i2c_msg *msg, int nmsgs) { struct mvtwsi_i2c_dev *dev = dev_get_priv(bus); struct i2c_msg *dmsg, *omsg, dummy; + u8 *addr_buf_ptr; + u8 addr_buf[4]; + int i; memset(&dummy, 0, sizeof(struct i2c_msg)); @@ -873,12 +876,17 @@ static int mvtwsi_i2c_xfer(struct udevice *bus, struct i2c_msg *msg, int nmsgs) omsg = nmsgs == 1 ? &dummy : msg; dmsg = nmsgs == 1 ? msg : msg + 1; + /* We need to swap the register address if its size is > 1 */ + addr_buf_ptr = &addr_buf[0]; + for (i = omsg->len; i > 0; i--) + *addr_buf_ptr++ = omsg->buf[i - 1]; + if (dmsg->flags & I2C_M_RD) - return __twsi_i2c_read(dev->base, dmsg->addr, omsg->buf, + return __twsi_i2c_read(dev->base, dmsg->addr, addr_buf, omsg->len, dmsg->buf, dmsg->len, dev->tick); else - return __twsi_i2c_write(dev->base, dmsg->addr, omsg->buf, + return __twsi_i2c_write(dev->base, dmsg->addr, addr_buf, omsg->len, dmsg->buf, dmsg->len, dev->tick); } -- 2.7.4