diff mbox

[RFC,1/2] i2c: sh_mobile: refactor DMA setup

Message ID 1418217709-26392-2-git-send-email-wsa@the-dreams.de
State Superseded
Headers show

Commit Message

Wolfram Sang Dec. 10, 2014, 1:21 p.m. UTC
From: Wolfram Sang <wsa+renesas@sang-engineering.com>

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>
---
 drivers/i2c/busses/i2c-sh_mobile.c | 35 ++++++++++++++++-------------------
 1 file changed, 16 insertions(+), 19 deletions(-)

Comments

Sergei Shtylyov Dec. 10, 2014, 7:06 p.m. UTC | #1
Hello.

On 12/10/2014 04:21 PM, Wolfram Sang wrote:

> From: Wolfram Sang <wsa+renesas@sang-engineering.com>

> 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>
> ---
>   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 b9c8cf2aac2c..636f2297143a 100644
> --- a/drivers/i2c/busses/i2c-sh_mobile.c
> +++ b/drivers/i2c/busses/i2c-sh_mobile.c
[...]
> @@ -749,21 +749,18 @@ 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)

    Hm, alignment style changed...

[...]
> @@ -891,13 +886,15 @@ 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);

    The alignment of this line is strange: it's neither here nor there, i.e. 
not aligned to the next char after ( above and still contains spaces. I think 
we want the old way of the alignment kept, i.e. the line starting under 
'pd->dev'...

> +	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);

    Likewise.

[...]

WBR, Sergei

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Wolfram Sang Dec. 16, 2014, 11:34 a.m. UTC | #2
>    Hm, alignment style changed...

I am not too strict on that as long as the result is somewhat readable.

I'd be more interested in your thoughts about the general approach taken
in this series.
Sergei Shtylyov Dec. 16, 2014, 9:06 p.m. UTC | #3
Hello.

On 12/16/2014 02:34 PM, Wolfram Sang wrote:

>>     Hm, alignment style changed...

> I am not too strict on that as long as the result is somewhat readable.

> I'd be more interested in your thoughts about the general approach taken
> in this series.

    Sorry, I'm not very familiar with this driver (and busy with other stuff 
currently).

WBR, Sergei

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diff mbox

Patch

diff --git a/drivers/i2c/busses/i2c-sh_mobile.c b/drivers/i2c/busses/i2c-sh_mobile.c
index b9c8cf2aac2c..636f2297143a 100644
--- a/drivers/i2c/busses/i2c-sh_mobile.c
+++ b/drivers/i2c/busses/i2c-sh_mobile.c
@@ -552,7 +552,7 @@  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);
@@ -749,21 +749,18 @@  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));
@@ -780,25 +777,23 @@  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);
 	}
 }
 
@@ -891,13 +886,15 @@  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;