From e844a7997dfbce687c7afa9d40f8a3b278e08735 Mon Sep 17 00:00:00 2001 From: Wolfram Sang Date: Tue, 16 Dec 2014 13:31:25 +0100 Subject: [PATCH] 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 Signed-off-by: Wolfram Sang --- drivers/i2c/busses/i2c-sh_mobile.c | 35 ++++++++++++++---------------- 1 file changed, 16 insertions(+), 19 deletions(-) diff --git a/drivers/i2c/busses/i2c-sh_mobile.c b/drivers/i2c/busses/i2c-sh_mobile.c index d7efaf44868b..b49e946b2940 100644 --- a/drivers/i2c/busses/i2c-sh_mobile.c +++ b/drivers/i2c/busses/i2c-sh_mobile.c @@ -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;