blob: b9b5d2ff209829da1495c40e41ef26bed23d4cb2 [file] [log] [blame]
From 44f55eb0472b8711fbee7cb4f916b0219013fb5b Mon Sep 17 00:00:00 2001
From: Wolfram Sang <wsa+renesas@sang-engineering.com>
Date: Sat, 4 Nov 2017 21:20:08 +0100
Subject: [PATCH 0543/1795] i2c: sh_mobile: use core helper to decide when to
use DMA
This ensures that we fall back to PIO if the message length is too small
for DMA being useful. Otherwise, we use DMA. A bounce buffer might be
applied by the helper if the original message buffer is not DMA safe.
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
(cherry picked from commit fe23aa9a1670b8800b251fc0400425e765c81880)
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
drivers/i2c/busses/i2c-sh_mobile.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/drivers/i2c/busses/i2c-sh_mobile.c b/drivers/i2c/busses/i2c-sh_mobile.c
index bc1605a31534..b01607b4fce2 100644
--- a/drivers/i2c/busses/i2c-sh_mobile.c
+++ b/drivers/i2c/busses/i2c-sh_mobile.c
@@ -144,6 +144,7 @@ struct sh_mobile_i2c_data {
struct dma_chan *dma_rx;
struct scatterlist sg;
enum dma_data_direction dma_direction;
+ u8 *dma_buf;
};
struct sh_mobile_dt_config {
@@ -501,6 +502,8 @@ 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);
}
@@ -561,7 +564,7 @@ static void sh_mobile_i2c_xfer_dma(struct sh_mobile_i2c_data *pd)
if (IS_ERR(chan))
return;
- dma_addr = dma_map_single(chan->device->dev, pd->msg->buf, pd->msg->len, dir);
+ dma_addr = dma_map_single(chan->device->dev, pd->dma_buf, pd->msg->len, dir);
if (dma_mapping_error(chan->device->dev, dma_addr)) {
dev_dbg(pd->dev, "dma map failed, using PIO\n");
return;
@@ -618,7 +621,8 @@ static int start_ch(struct sh_mobile_i2c_data *pd, struct i2c_msg *usr_msg,
pd->pos = -1;
pd->sr = 0;
- if (pd->msg->len > 8)
+ pd->dma_buf = i2c_get_dma_safe_msg_buf(pd->msg, 8);
+ if (pd->dma_buf)
sh_mobile_i2c_xfer_dma(pd);
/* Enable all interrupts to begin with */
--
2.19.0