From 52db223e4cf414e216890643cda33e2626554471 Mon Sep 17 00:00:00 2001 From: Sricharan R Date: Fri, 26 Feb 2016 21:28:54 +0530 Subject: [PATCH] i2c: qup: Fix fifo handling after adding V2 support After the addition of V2 support, there was a regression observed when testing it on MSM8996. The reason is driver puts the controller in to RUN state and writes the data to be 'tx' ed in fifo. But controller has to be put in to 'PAUSE' state and data has to written to fifo. Then should be put in to 'RUN' state separately. Signed-off-by: Sricharan R Tested-by: Pramod Gurav Signed-off-by: Wolfram Sang --- drivers/i2c/busses/i2c-qup.c | 46 ++++++++++++++++++++++++++++++------ 1 file changed, 39 insertions(+), 7 deletions(-) diff --git a/drivers/i2c/busses/i2c-qup.c b/drivers/i2c/busses/i2c-qup.c index 30f3a2bf972d..23eaabb19f96 100644 --- a/drivers/i2c/busses/i2c-qup.c +++ b/drivers/i2c/busses/i2c-qup.c @@ -372,6 +372,38 @@ static void qup_i2c_set_write_mode(struct qup_i2c_dev *qup, struct i2c_msg *msg) } } +static int check_for_fifo_space(struct qup_i2c_dev *qup) +{ + int ret; + + ret = qup_i2c_change_state(qup, QUP_PAUSE_STATE); + if (ret) + goto out; + + ret = qup_i2c_wait_ready(qup, QUP_OUT_FULL, + RESET_BIT, 4 * ONE_BYTE); + if (ret) { + /* Fifo is full. Drain out the fifo */ + ret = qup_i2c_change_state(qup, QUP_RUN_STATE); + if (ret) + goto out; + + ret = qup_i2c_wait_ready(qup, QUP_OUT_NOT_EMPTY, + RESET_BIT, 256 * ONE_BYTE); + if (ret) { + dev_err(qup->dev, "timeout for fifo out full"); + goto out; + } + + ret = qup_i2c_change_state(qup, QUP_PAUSE_STATE); + if (ret) + goto out; + } + +out: + return ret; +} + static int qup_i2c_issue_write(struct qup_i2c_dev *qup, struct i2c_msg *msg) { u32 addr = msg->addr << 1; @@ -390,8 +422,7 @@ static int qup_i2c_issue_write(struct qup_i2c_dev *qup, struct i2c_msg *msg) while (qup->pos < msg->len) { /* Check that there's space in the FIFO for our pair */ - ret = qup_i2c_wait_ready(qup, QUP_OUT_FULL, RESET_BIT, - 4 * ONE_BYTE); + ret = check_for_fifo_space(qup); if (ret) return ret; @@ -413,6 +444,8 @@ static int qup_i2c_issue_write(struct qup_i2c_dev *qup, struct i2c_msg *msg) idx++; } + ret = qup_i2c_change_state(qup, QUP_RUN_STATE); + return ret; } @@ -441,12 +474,9 @@ static int qup_i2c_send_data(struct qup_i2c_dev *qup, int tlen, u8 *tbuf, int ret = 0; while (len > 0) { - ret = qup_i2c_wait_ready(qup, QUP_OUT_FULL, - RESET_BIT, 4 * ONE_BYTE); - if (ret) { - dev_err(qup->dev, "timeout for fifo out full"); + ret = check_for_fifo_space(qup); + if (ret) return ret; - } t = (len >= 4) ? 4 : len; @@ -465,6 +495,8 @@ static int qup_i2c_send_data(struct qup_i2c_dev *qup, int tlen, u8 *tbuf, len -= 4; } + ret = qup_i2c_change_state(qup, QUP_RUN_STATE); + return ret; } -- 2.20.1