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-rw-r--r--drivers/i2c/busses/i2c-sh_mobile.c35
1 files changed, 13 insertions, 22 deletions
diff --git a/drivers/i2c/busses/i2c-sh_mobile.c b/drivers/i2c/busses/i2c-sh_mobile.c
index 5fda4188a9e5..818cab14e87c 100644
--- a/drivers/i2c/busses/i2c-sh_mobile.c
+++ b/drivers/i2c/busses/i2c-sh_mobile.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
/*
* SuperH Mobile I2C Controller
*
@@ -7,15 +8,6 @@
*
* Portions of the code based on out-of-tree driver i2c-sh7343.c
* Copyright (c) 2006 Carlos Munoz <carlos@kenati.com>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
*/
#include <linux/clk.h>
@@ -515,8 +507,6 @@ static void sh_mobile_i2c_dma_callback(void *data)
pd->pos = pd->msg->len;
pd->stop_after_dma = true;
- i2c_release_dma_safe_msg_buf(pd->msg, pd->dma_buf);
-
iic_set_clr(pd, ICIC, 0, ICIC_TDMAE | ICIC_RDMAE);
}
@@ -610,14 +600,9 @@ static void sh_mobile_i2c_xfer_dma(struct sh_mobile_i2c_data *pd)
dma_async_issue_pending(chan);
}
-static int start_ch(struct sh_mobile_i2c_data *pd, struct i2c_msg *usr_msg,
- bool do_init)
+static void start_ch(struct sh_mobile_i2c_data *pd, struct i2c_msg *usr_msg,
+ bool do_init)
{
- if (usr_msg->len == 0 && (usr_msg->flags & I2C_M_RD)) {
- dev_err(pd->dev, "Unsupported zero length i2c read\n");
- return -EOPNOTSUPP;
- }
-
if (do_init) {
/* Initialize channel registers */
iic_wr(pd, ICCR, ICCR_SCP);
@@ -640,7 +625,6 @@ static int start_ch(struct sh_mobile_i2c_data *pd, struct i2c_msg *usr_msg,
/* Enable all interrupts to begin with */
iic_wr(pd, ICIC, ICIC_DTEE | ICIC_WAITE | ICIC_ALE | ICIC_TACKE);
- return 0;
}
static int poll_dte(struct sh_mobile_i2c_data *pd)
@@ -711,9 +695,7 @@ static int sh_mobile_i2c_xfer(struct i2c_adapter *adapter,
pd->send_stop = i == num - 1 || msg->flags & I2C_M_STOP;
pd->stop_after_dma = false;
- err = start_ch(pd, msg, do_start);
- if (err)
- break;
+ start_ch(pd, msg, do_start);
if (do_start)
i2c_op(pd, OP_START, 0);
@@ -722,6 +704,10 @@ static int sh_mobile_i2c_xfer(struct i2c_adapter *adapter,
timeout = wait_event_timeout(pd->wait,
pd->sr & (ICSR_TACK | SW_DONE),
adapter->timeout);
+
+ /* 'stop_after_dma' tells if DMA transfer was complete */
+ i2c_put_dma_safe_msg_buf(pd->dma_buf, pd->msg, pd->stop_after_dma);
+
if (!timeout) {
dev_err(pd->dev, "Transfer request timed out\n");
if (pd->dma_direction != DMA_NONE)
@@ -758,6 +744,10 @@ static const struct i2c_algorithm sh_mobile_i2c_algorithm = {
.master_xfer = sh_mobile_i2c_xfer,
};
+static const struct i2c_adapter_quirks sh_mobile_i2c_quirks = {
+ .flags = I2C_AQ_NO_ZERO_LEN_READ,
+};
+
/*
* r8a7740 chip has lasting errata on I2C I/O pad reset.
* this is work-around for it.
@@ -925,6 +915,7 @@ static int sh_mobile_i2c_probe(struct platform_device *dev)
adap->owner = THIS_MODULE;
adap->algo = &sh_mobile_i2c_algorithm;
+ adap->quirks = &sh_mobile_i2c_quirks;
adap->dev.parent = &dev->dev;
adap->retries = 5;
adap->nr = dev->id;
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