i2c: sh_mobile: refactor DMA setup

Refactor DMA setup to keep the errno so we can implement better
deferred probe support in the next step.

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 2014-12-16 13:31:25 +01:00 committed by Wolfram Sang
parent 00d8689b85
commit e844a7997d

View File

@ -548,7 +548,7 @@ static void sh_mobile_i2c_xfer_dma(struct sh_mobile_i2c_data *pd)
dma_addr_t dma_addr;
dma_cookie_t cookie;
if (!chan)
if (IS_ERR(chan))
return;
dma_addr = dma_map_single(chan->device->dev, pd->msg->buf, pd->msg->len, dir);
@ -747,21 +747,18 @@ static const struct of_device_id sh_mobile_i2c_dt_ids[] = {
};
MODULE_DEVICE_TABLE(of, sh_mobile_i2c_dt_ids);
static int sh_mobile_i2c_request_dma_chan(struct device *dev, enum dma_transfer_direction dir,
dma_addr_t port_addr, struct dma_chan **chan_ptr)
static struct dma_chan *sh_mobile_i2c_request_dma_chan(struct device *dev,
enum dma_transfer_direction dir, dma_addr_t port_addr)
{
struct dma_chan *chan;
struct dma_slave_config cfg;
char *chan_name = dir == DMA_MEM_TO_DEV ? "tx" : "rx";
int ret;
*chan_ptr = NULL;
chan = dma_request_slave_channel_reason(dev, chan_name);
if (IS_ERR(chan)) {
ret = PTR_ERR(chan);
dev_dbg(dev, "request_channel failed for %s (%d)\n", chan_name, ret);
return ret;
return chan;
}
memset(&cfg, 0, sizeof(cfg));
@ -778,25 +775,23 @@ static int sh_mobile_i2c_request_dma_chan(struct device *dev, enum dma_transfer_
if (ret) {
dev_dbg(dev, "slave_config failed for %s (%d)\n", chan_name, ret);
dma_release_channel(chan);
return ret;
return ERR_PTR(ret);
}
*chan_ptr = chan;
dev_dbg(dev, "got DMA channel for %s\n", chan_name);
return 0;
return chan;
}
static void sh_mobile_i2c_release_dma(struct sh_mobile_i2c_data *pd)
{
if (pd->dma_tx) {
if (!IS_ERR(pd->dma_tx)) {
dma_release_channel(pd->dma_tx);
pd->dma_tx = NULL;
pd->dma_tx = ERR_PTR(-EPROBE_DEFER);
}
if (pd->dma_rx) {
if (!IS_ERR(pd->dma_rx)) {
dma_release_channel(pd->dma_rx);
pd->dma_rx = NULL;
pd->dma_rx = ERR_PTR(-EPROBE_DEFER);
}
}
@ -889,13 +884,15 @@ static int sh_mobile_i2c_probe(struct platform_device *dev)
/* Init DMA */
sg_init_table(&pd->sg, 1);
pd->dma_direction = DMA_NONE;
ret = sh_mobile_i2c_request_dma_chan(pd->dev, DMA_DEV_TO_MEM,
res->start + ICDR, &pd->dma_rx);
pd->dma_rx = sh_mobile_i2c_request_dma_chan(pd->dev, DMA_DEV_TO_MEM,
res->start + ICDR);
ret = PTR_ERR(pd->dma_rx);
if (ret == -EPROBE_DEFER)
return ret;
ret = sh_mobile_i2c_request_dma_chan(pd->dev, DMA_MEM_TO_DEV,
res->start + ICDR, &pd->dma_tx);
pd->dma_tx = sh_mobile_i2c_request_dma_chan(pd->dev, DMA_MEM_TO_DEV,
res->start + ICDR);
ret = PTR_ERR(pd->dma_tx);
if (ret == -EPROBE_DEFER) {
sh_mobile_i2c_release_dma(pd);
return ret;