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>
This commit is contained in:
Wolfram Sang 2017-11-04 21:20:08 +01:00 committed by Wolfram Sang
parent d4e01186ae
commit fe23aa9a16

View File

@ -144,6 +144,7 @@ struct sh_mobile_i2c_data {
struct dma_chan *dma_rx; struct dma_chan *dma_rx;
struct scatterlist sg; struct scatterlist sg;
enum dma_data_direction dma_direction; enum dma_data_direction dma_direction;
u8 *dma_buf;
}; };
struct sh_mobile_dt_config { struct sh_mobile_dt_config {
@ -501,6 +502,8 @@ static void sh_mobile_i2c_dma_callback(void *data)
pd->pos = pd->msg->len; pd->pos = pd->msg->len;
pd->stop_after_dma = true; 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); 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)) if (IS_ERR(chan))
return; 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)) { if (dma_mapping_error(chan->device->dev, dma_addr)) {
dev_dbg(pd->dev, "dma map failed, using PIO\n"); dev_dbg(pd->dev, "dma map failed, using PIO\n");
return; return;
@ -618,7 +621,8 @@ static int start_ch(struct sh_mobile_i2c_data *pd, struct i2c_msg *usr_msg,
pd->pos = -1; pd->pos = -1;
pd->sr = 0; 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); sh_mobile_i2c_xfer_dma(pd);
/* Enable all interrupts to begin with */ /* Enable all interrupts to begin with */