1 files changed, 54 insertions, 58 deletions

diff --git a/drivers/i2c/busses/i2c-sh_mobile.c b/drivers/i2c/busses/i2c-sh_mobile.c
index d7efaf44868b..440d5dbc8b5f 100644
--- a/drivers/i2c/busses/i2c-sh_mobile.c
+++ b/drivers/i2c/busses/i2c-sh_mobile.c
@@ -140,6 +140,7 @@ struct sh_mobile_i2c_data {
 	int sr;
 	bool send_stop;
 
+	struct resource *res;
 	struct dma_chan *dma_tx;
 	struct dma_chan *dma_rx;
 	struct scatterlist sg;
@@ -539,6 +540,42 @@ static void sh_mobile_i2c_dma_callback(void *data)
 	iic_set_clr(pd, ICIC, 0, ICIC_TDMAE | ICIC_RDMAE);
 }
 
+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 = 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 chan;
+	}
+
+	memset(&cfg, 0, sizeof(cfg));
+	cfg.direction = dir;
+	if (dir == DMA_MEM_TO_DEV) {
+		cfg.dst_addr = port_addr;
+		cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+	} else {
+		cfg.src_addr = port_addr;
+		cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+	}
+
+	ret = dmaengine_slave_config(chan, &cfg);
+	if (ret) {
+		dev_dbg(dev, "slave_config failed for %s (%d)\n", chan_name, ret);
+		dma_release_channel(chan);
+		return ERR_PTR(ret);
+	}
+
+	dev_dbg(dev, "got DMA channel for %s\n", chan_name);
+	return chan;
+}
+
 static void sh_mobile_i2c_xfer_dma(struct sh_mobile_i2c_data *pd)
 {
 	bool read = pd->msg->flags & I2C_M_RD;
@@ -548,7 +585,16 @@ 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 (PTR_ERR(chan) == -EPROBE_DEFER) {
+		if (read)
+			chan = pd->dma_rx = sh_mobile_i2c_request_dma_chan(pd->dev, DMA_DEV_TO_MEM,
+									   pd->res->start + ICDR);
+		else
+			chan = pd->dma_tx = sh_mobile_i2c_request_dma_chan(pd->dev, DMA_MEM_TO_DEV,
+									   pd->res->start + ICDR);
+	}
+
+	if (IS_ERR(chan))
 		return;
 
 	dma_addr = dma_map_single(chan->device->dev, pd->msg->buf, pd->msg->len, dir);
@@ -747,56 +793,16 @@ 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)
-{
-	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;
-	}
-
-	memset(&cfg, 0, sizeof(cfg));
-	cfg.direction = dir;
-	if (dir == DMA_MEM_TO_DEV) {
-		cfg.dst_addr = port_addr;
-		cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
-	} else {
-		cfg.src_addr = port_addr;
-		cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
-	}
-
-	ret = dmaengine_slave_config(chan, &cfg);
-	if (ret) {
-		dev_dbg(dev, "slave_config failed for %s (%d)\n", chan_name, ret);
-		dma_release_channel(chan);
-		return ret;
-	}
-
-	*chan_ptr = chan;
-
-	dev_dbg(dev, "got DMA channel for %s\n", chan_name);
-	return 0;
-}
-
 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);
 	}
 }
 
@@ -849,6 +855,7 @@ static int sh_mobile_i2c_probe(struct platform_device *dev)
 
 	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
 
+	pd->res = res;
 	pd->reg = devm_ioremap_resource(&dev->dev, res);
 	if (IS_ERR(pd->reg))
 		return PTR_ERR(pd->reg);
@@ -889,17 +896,7 @@ 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);
-	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);
-	if (ret == -EPROBE_DEFER) {
-		sh_mobile_i2c_release_dma(pd);
-		return ret;
-	}
+	pd->dma_rx = pd->dma_tx = ERR_PTR(-EPROBE_DEFER);
 
 	/* Enable Runtime PM for this device.
 	 *
@@ -937,8 +934,7 @@ static int sh_mobile_i2c_probe(struct platform_device *dev)
 		return ret;
 	}
 
-	dev_info(&dev->dev, "I2C adapter %d, bus speed %lu Hz, DMA=%c\n",
-		 adap->nr, pd->bus_speed, (pd->dma_rx || pd->dma_tx) ? 'y' : 'n');
+	dev_info(&dev->dev, "I2C adapter %d, bus speed %lu Hz\n", adap->nr, pd->bus_speed);
 
 	return 0;
 }