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Groups > linux.kernel > #1265328 > unrolled thread

[PATCH v2] spi: mediatek: single device does not require cs_gpios

Started byNicolas Boichat <drinkcat@chromium.org>
First post2015-11-09 05:20 +0100
Last post2015-11-14 03:30 +0100
Articles 2 — 2 participants

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  [PATCH v2] spi: mediatek: single device does not require cs_gpios Nicolas Boichat <drinkcat@chromium.org> - 2015-11-09 05:20 +0100
    Re: [PATCH v2] spi: mediatek: single device does not require  cs_gpios lei liu <leilk.liu@mediatek.com> - 2015-11-14 03:30 +0100

#1265328 — [PATCH v2] spi: mediatek: single device does not require cs_gpios

FromNicolas Boichat <drinkcat@chromium.org>
Date2015-11-09 05:20 +0100
Subject[PATCH v2] spi: mediatek: single device does not require cs_gpios
Message-ID<qsM5Y-1kM-3@gated-at.bofh.it>
When only one device is present, it is not necessary to specify
cs_gpios, as the CS line can be controlled by the hardware
module.

Without this patch, older device tree bindings used before
37457607 "spi: mediatek: mt8173 spi multiple devices support"
would cause a panic on boot. This fixes the crash, and
re-introduces backward compatibility.

Signed-off-by: Nicolas Boichat <drinkcat@chromium.org>
---

v2: Use gpio_is_valid()

Applies on top of broonie/spi.git/for-next.

 drivers/spi/spi-mt65xx.c | 26 ++++++++++++++++++--------
 1 file changed, 18 insertions(+), 8 deletions(-)

diff --git a/drivers/spi/spi-mt65xx.c b/drivers/spi/spi-mt65xx.c
index 563954a..7840067 100644
--- a/drivers/spi/spi-mt65xx.c
+++ b/drivers/spi/spi-mt65xx.c
@@ -410,7 +410,7 @@ static int mtk_spi_setup(struct spi_device *spi)
 	if (!spi->controller_data)
 		spi->controller_data = (void *)&mtk_default_chip_info;
 
-	if (mdata->dev_comp->need_pad_sel)
+	if (mdata->dev_comp->need_pad_sel && gpio_is_valid(spi->cs_gpio))
 		gpio_direction_output(spi->cs_gpio, !(spi->mode & SPI_CS_HIGH));
 
 	return 0;
@@ -632,13 +632,23 @@ static int mtk_spi_probe(struct platform_device *pdev)
 			goto err_put_master;
 		}
 
-		for (i = 0; i < master->num_chipselect; i++) {
-			ret = devm_gpio_request(&pdev->dev, master->cs_gpios[i],
-						dev_name(&pdev->dev));
-			if (ret) {
-				dev_err(&pdev->dev,
-					"can't get CS GPIO %i\n", i);
-				goto err_put_master;
+		if (!master->cs_gpios && master->num_chipselect > 1) {
+			dev_err(&pdev->dev,
+				"cs_gpios not specified and num_chipselect > 1\n");
+			ret = -EINVAL;
+			goto err_put_master;
+		}
+
+		if (master->cs_gpios) {
+			for (i = 0; i < master->num_chipselect; i++) {
+				ret = devm_gpio_request(&pdev->dev,
+							master->cs_gpios[i],
+							dev_name(&pdev->dev));
+				if (ret) {
+					dev_err(&pdev->dev,
+						"can't get CS GPIO %i\n", i);
+					goto err_put_master;
+				}
 			}
 		}
 	}
-- 
2.6.0.rc2.230.g3dd15c0

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#1269391 — Re: [PATCH v2] spi: mediatek: single device does not require cs_gpios

Fromlei liu <leilk.liu@mediatek.com>
Date2015-11-14 03:30 +0100
SubjectRe: [PATCH v2] spi: mediatek: single device does not require cs_gpios
Message-ID<quyLf-6gI-5@gated-at.bofh.it>
In reply to#1265328
On Mon, 2015-11-09 at 12:14 +0800, Nicolas Boichat wrote:
> When only one device is present, it is not necessary to specify
> cs_gpios, as the CS line can be controlled by the hardware
> module.
> 
> Without this patch, older device tree bindings used before
> 37457607 "spi: mediatek: mt8173 spi multiple devices support"
> would cause a panic on boot. This fixes the crash, and
> re-introduces backward compatibility.
> 
> Signed-off-by: Nicolas Boichat <drinkcat@chromium.org>

Acked-by: Leilk Liu <leilk.liu@mediatek.com>

> ---
> 
> v2: Use gpio_is_valid()
> 
> Applies on top of broonie/spi.git/for-next.
> 
>  drivers/spi/spi-mt65xx.c | 26 ++++++++++++++++++--------
>  1 file changed, 18 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/spi/spi-mt65xx.c b/drivers/spi/spi-mt65xx.c
> index 563954a..7840067 100644
> --- a/drivers/spi/spi-mt65xx.c
> +++ b/drivers/spi/spi-mt65xx.c
> @@ -410,7 +410,7 @@ static int mtk_spi_setup(struct spi_device *spi)
>  	if (!spi->controller_data)
>  		spi->controller_data = (void *)&mtk_default_chip_info;
>  
> -	if (mdata->dev_comp->need_pad_sel)
> +	if (mdata->dev_comp->need_pad_sel && gpio_is_valid(spi->cs_gpio))
>  		gpio_direction_output(spi->cs_gpio, !(spi->mode & SPI_CS_HIGH));
>  
>  	return 0;
> @@ -632,13 +632,23 @@ static int mtk_spi_probe(struct platform_device *pdev)
>  			goto err_put_master;
>  		}
>  
> -		for (i = 0; i < master->num_chipselect; i++) {
> -			ret = devm_gpio_request(&pdev->dev, master->cs_gpios[i],
> -						dev_name(&pdev->dev));
> -			if (ret) {
> -				dev_err(&pdev->dev,
> -					"can't get CS GPIO %i\n", i);
> -				goto err_put_master;
> +		if (!master->cs_gpios && master->num_chipselect > 1) {
> +			dev_err(&pdev->dev,
> +				"cs_gpios not specified and num_chipselect > 1\n");
> +			ret = -EINVAL;
> +			goto err_put_master;
> +		}
> +
> +		if (master->cs_gpios) {
> +			for (i = 0; i < master->num_chipselect; i++) {
> +				ret = devm_gpio_request(&pdev->dev,
> +							master->cs_gpios[i],
> +							dev_name(&pdev->dev));
> +				if (ret) {
> +					dev_err(&pdev->dev,
> +						"can't get CS GPIO %i\n", i);
> +					goto err_put_master;
> +				}
>  			}
>  		}
>  	}


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