[PATCH v2 0/2] mtd: fsl-quadspi: Update slave device hwcap based on mode provided in dtsi file

[PATCH v2 0/2] mtd: fsl-quadspi: Update slave device hwcap based on mode provided in dtsi file

[Yogesh Gaur]

This patch-set added support to update hwcap of slave device connected to
FSL QUADSPI controller by reading values from the device tree files.

Mode information is available via "spi-tx-bus-width" and
"spi-rx-bus-width" nodes of device tree for the connected slave device.

Update read and write hwcap capability for slave device by reading
"spi-rx-bus-width" and "spi-tx-bus-width" respectively.

Added usage example for spi-rx/tx-bus-width properties in spi-bus.txt

Depends on
 https://patchwork.ozlabs.org/project/linux-mtd/list/?series=26084

Yogesh Gaur (2):
  mtd: fsl-quadspi: Update slave device hwcap based on mode provided in
    dtsi file
  dt-bindings: spi: updated usage example for spi-rx/tx-bus-width
    properties

Changes for v2:
- Drop patch 'dt-bindings: fsl-quadspi: spi-rx/tx-bus-width usage example'
- Added usage example for spi-rx/tx-bus-width properties in spi-bus.txt

 Documentation/devicetree/bindings/spi/spi-bus.txt |  2 +
 drivers/mtd/spi-nor/fsl-quadspi.c                 | 56 +++++++++++++++++++++--
 2 files changed, 53 insertions(+), 5 deletions(-)

-- 
1.9.1

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[PATCH v2 1/2] mtd: fsl-quadspi: Update slave device hwcap based on mode provided in dtsi file

[Yogesh Gaur]

FSL QuadSPI controller supports Single, dual, quad modes of operation.
Mode information is available via "spi-tx-bus-width" and
"spi-rx-bus-width" nodes of device tree for the connected slave device.

Update read and write hwcap capability for slave device by reading
"spi-rx-bus-width" and "spi-tx-bus-width" respectively.
Assign hwcaps mask to minimal caps for the slave node i.e.
	SNOR_HWCAPS_READ | SNOR_HWCAPS_PP

If value not provided in device tree file, then fallback to default
mode i.e. SNOR_HWCAPS_READ_1_1_4 and SNOR_HWCAPS_PP.

Signed-off-by: Prabhakar Kushwaha <prabhakar.kushwaha-3arQi8VN3Tc@public.gmane.org>
Signed-off-by: Yogesh Gaur <yogeshnarayan.gaur-3arQi8VN3Tc@public.gmane.org>
---
Changes for v2:
- None

 drivers/mtd/spi-nor/fsl-quadspi.c | 56 +++++++++++++++++++++++++++++++++++----
 1 file changed, 51 insertions(+), 5 deletions(-)

diff --git a/drivers/mtd/spi-nor/fsl-quadspi.c b/drivers/mtd/spi-nor/fsl-quadspi.c
index b9c5918..1503e0c 100644
--- a/drivers/mtd/spi-nor/fsl-quadspi.c
+++ b/drivers/mtd/spi-nor/fsl-quadspi.c
@@ -994,17 +994,14 @@ static void fsl_qspi_unprep(struct spi_nor *nor, enum spi_nor_ops ops)
 
 static int fsl_qspi_probe(struct platform_device *pdev)
 {
-	const struct spi_nor_hwcaps hwcaps = {
-		.mask = SNOR_HWCAPS_READ_1_1_4 |
-			SNOR_HWCAPS_PP,
-	};
+	struct spi_nor_hwcaps hwcaps;
 	struct device_node *np = pdev->dev.of_node;
 	struct device *dev = &pdev->dev;
 	struct fsl_qspi *q;
 	struct resource *res;
 	struct spi_nor *nor;
 	struct mtd_info *mtd;
-	int ret, i = 0;
+	int ret, i = 0, value;
 
 	q = devm_kzalloc(dev, sizeof(*q), GFP_KERNEL);
 	if (!q)
@@ -1077,6 +1074,10 @@ static int fsl_qspi_probe(struct platform_device *pdev)
 
 	/* iterate the subnodes. */
 	for_each_available_child_of_node(dev->of_node, np) {
+		/* Reset hwcaps mask to minimal caps for the slave node. */
+		hwcaps.mask = SNOR_HWCAPS_READ | SNOR_HWCAPS_PP;
+		value = 0;
+
 		/* skip the holes */
 		if (!q->has_second_chip)
 			i *= 2;
@@ -1106,6 +1107,51 @@ static int fsl_qspi_probe(struct platform_device *pdev)
 		/* set the chip address for READID */
 		fsl_qspi_set_base_addr(q, nor);
 
+		/*
+		 * If spi-rx-bus-width and spi-tx-bus-width not defined assign
+		 * default hardware capabilities SNOR_HWCAPS_READ_1_1_4 and
+		 * SNOR_HWCAPS_PP supported by the Quad-SPI controller.
+		 */
+		if (!of_property_read_u32(np, "spi-rx-bus-width", &value)) {
+			switch (value) {
+			case 1:
+				hwcaps.mask |= SNOR_HWCAPS_READ |
+					       SNOR_HWCAPS_READ_FAST;
+				break;
+			case 2:
+				hwcaps.mask |= SNOR_HWCAPS_READ_1_1_2 |
+					       SNOR_HWCAPS_READ_1_2_2;
+				break;
+			case 4:
+				hwcaps.mask |= SNOR_HWCAPS_READ_1_1_4 |
+					       SNOR_HWCAPS_READ_1_4_4;
+				break;
+			default:
+				dev_err(dev,
+					"spi-rx-bus-width %d not supported\n",
+					value);
+				break;
+			}
+		} else
+			hwcaps.mask |= SNOR_HWCAPS_READ_1_1_4;
+
+		if (!of_property_read_u32(np, "spi-tx-bus-width", &value)) {
+			switch (value) {
+			case 1:
+				hwcaps.mask |= SNOR_HWCAPS_PP;
+				break;
+			case 4:
+				hwcaps.mask |= SNOR_HWCAPS_PP_1_1_4 |
+					       SNOR_HWCAPS_PP_1_4_4;
+				break;
+			default:
+				dev_err(dev,
+					"spi-tx-bus-width %d not supported\n",
+					value);
+				break;
+			}
+		}
+
 		ret = spi_nor_scan(nor, NULL, &hwcaps);
 		if (ret)
 			goto mutex_failed;
-- 
1.9.1

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[PATCH v2 2/2] dt-bindings: spi: updated usage example for spi-rx/tx-bus-width properties

[Yogesh Gaur]

Updated usage example by adding properties spi-rx-bus-width
and spi-tx-bus-width for slave node binding.

Signed-off-by: Yogesh Gaur <yogeshnarayan.gaur-3arQi8VN3Tc@public.gmane.org>
---
Changes for v2:
- None

 Documentation/devicetree/bindings/spi/spi-bus.txt | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Documentation/devicetree/bindings/spi/spi-bus.txt b/Documentation/devicetree/bindings/spi/spi-bus.txt
index 1f6e86f..4dbe267 100644
--- a/Documentation/devicetree/bindings/spi/spi-bus.txt
+++ b/Documentation/devicetree/bindings/spi/spi-bus.txt
@@ -101,6 +101,8 @@ SPI example for an MPC5200 SPI bus:
 			compatible = "micrel,ks8995m";
 			spi-max-frequency = <1000000>;
 			reg = <0>;
+			spi-rx-bus-width = 4;
+			spi-tx-bus-width = 4;
 		};
 
 		codec@1 {
-- 
1.9.1

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Re: [PATCH v2 2/2] dt-bindings: spi: updated usage example for spi-rx/tx-bus-width properties

[Rob Herring]

On Fri, Feb 02, 2018 at 11:01:24AM +0530, Yogesh Gaur wrote:
> Updated usage example by adding properties spi-rx-bus-width
> and spi-tx-bus-width for slave node binding.
> 
> Signed-off-by: Yogesh Gaur <yogeshnarayan.gaur-3arQi8VN3Tc@public.gmane.org>
> ---
> Changes for v2:
> - None
> 
>  Documentation/devicetree/bindings/spi/spi-bus.txt | 2 ++
>  1 file changed, 2 insertions(+)

Reviewed-by: Rob Herring <robh-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
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Re: [PATCH v2 1/2] mtd: fsl-quadspi: Update slave device hwcap based on mode provided in dtsi file

[Cyrille Pitchen]

Hi Yogesh,

Le 02/02/2018 à 06:31, Yogesh Gaur a écrit :
> FSL QuadSPI controller supports Single, dual, quad modes of operation.
> Mode information is available via "spi-tx-bus-width" and
> "spi-rx-bus-width" nodes of device tree for the connected slave device.
> 
> Update read and write hwcap capability for slave device by reading
> "spi-rx-bus-width" and "spi-tx-bus-width" respectively.
> Assign hwcaps mask to minimal caps for the slave node i.e.
> 	SNOR_HWCAPS_READ | SNOR_HWCAPS_PP
> 
> If value not provided in device tree file, then fallback to default
> mode i.e. SNOR_HWCAPS_READ_1_1_4 and SNOR_HWCAPS_PP.
> 
> Signed-off-by: Prabhakar Kushwaha <prabhakar.kushwaha-3arQi8VN3Tc@public.gmane.org>
> Signed-off-by: Yogesh Gaur <yogeshnarayan.gaur-3arQi8VN3Tc@public.gmane.org>
> ---
> Changes for v2:
> - None
> 
>  drivers/mtd/spi-nor/fsl-quadspi.c | 56 +++++++++++++++++++++++++++++++++++----
>  1 file changed, 51 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/mtd/spi-nor/fsl-quadspi.c b/drivers/mtd/spi-nor/fsl-quadspi.c
> index b9c5918..1503e0c 100644
> --- a/drivers/mtd/spi-nor/fsl-quadspi.c
> +++ b/drivers/mtd/spi-nor/fsl-quadspi.c
> @@ -994,17 +994,14 @@ static void fsl_qspi_unprep(struct spi_nor *nor, enum spi_nor_ops ops)
>  
>  static int fsl_qspi_probe(struct platform_device *pdev)
>  {
> -	const struct spi_nor_hwcaps hwcaps = {
> -		.mask = SNOR_HWCAPS_READ_1_1_4 |
> -			SNOR_HWCAPS_PP,
> -	};
> +	struct spi_nor_hwcaps hwcaps;
>  	struct device_node *np = pdev->dev.of_node;
>  	struct device *dev = &pdev->dev;
>  	struct fsl_qspi *q;
>  	struct resource *res;
>  	struct spi_nor *nor;
>  	struct mtd_info *mtd;
> -	int ret, i = 0;
> +	int ret, i = 0, value;
>  
>  	q = devm_kzalloc(dev, sizeof(*q), GFP_KERNEL);
>  	if (!q)
> @@ -1077,6 +1074,10 @@ static int fsl_qspi_probe(struct platform_device *pdev)
>  
>  	/* iterate the subnodes. */
>  	for_each_available_child_of_node(dev->of_node, np) {
> +		/* Reset hwcaps mask to minimal caps for the slave node. */
> +		hwcaps.mask = SNOR_HWCAPS_READ | SNOR_HWCAPS_PP;
> +		value = 0;
> +
>  		/* skip the holes */
>  		if (!q->has_second_chip)
>  			i *= 2;
> @@ -1106,6 +1107,51 @@ static int fsl_qspi_probe(struct platform_device *pdev)
>  		/* set the chip address for READID */
>  		fsl_qspi_set_base_addr(q, nor);
>  
> +		/*
> +		 * If spi-rx-bus-width and spi-tx-bus-width not defined assign
> +		 * default hardware capabilities SNOR_HWCAPS_READ_1_1_4 and
> +		 * SNOR_HWCAPS_PP supported by the Quad-SPI controller.
> +		 */
> +		if (!of_property_read_u32(np, "spi-rx-bus-width", &value)) {
> +			switch (value) {
> +			case 1:
> +				hwcaps.mask |= SNOR_HWCAPS_READ |
> +					       SNOR_HWCAPS_READ_FAST;
> +				break;
> +			case 2:
> +				hwcaps.mask |= SNOR_HWCAPS_READ_1_1_2 |
> +					       SNOR_HWCAPS_READ_1_2_2;

I guess there is a misunderstanding in the meaning of spi-rx-bus-width and
spi-tx-bus_width.

spi-rx-bus-width = <N>, resp. spi-tx-bus-width = <N>, means the SPI controller
can receive, resp. send, data on N I/O Lines.

Then let's take the example of some Fast Read X-Y-Z command:

the op code is *sent* on X I/O lines: you need to check spi-tx-bus-width
the address/mode/dummy bits are *sent* on Y I/O lines: check spi-tx-bus-width too
the data bits are *received* on Z I/O lines: check spi-rx-bus_width.

> +				break;
> +			case 4:
> +				hwcaps.mask |= SNOR_HWCAPS_READ_1_1_4 |
> +					       SNOR_HWCAPS_READ_1_4_4;

The same here: to allow SPI 1-4-4, you have to check that spi-tx-bus-width == 4.

So your usage of spi-{tx|rx}-bus-width is not consistent with the usage done in
the SPI subsystem. Please have a look at drivers/mtd/devices/m25p80.c, especially
how the SPI_RX_QUAD and SPI_TX_QUAD flags are used in the m25p_probe() function
to have a better idea of how it should work.

Also have a look at of_spi_parse_dt() in drivers/spi/spi.c, to figure out how the
SPI_{TX|RX}_{DUAL|QUAD} flags are set according to the spi-{tx|rx}-bus-width DT
properties.

> +				break;
> +			default:
> +				dev_err(dev,
> +					"spi-rx-bus-width %d not supported\n",
> +					value);
> +				break;
> +			}
> +		} else
> +			hwcaps.mask |= SNOR_HWCAPS_READ_1_1_4;

Not sure whether it passes checkpatch, you may have to add { } for the else
statement even if there is a single line as the if statement use { }.

Personally I don't mind that much. Please just check that your patch passes
checkpatch verification and it will be okay for me :)

Best regards,

Cyrille

> +
> +		if (!of_property_read_u32(np, "spi-tx-bus-width", &value)) {
> +			switch (value) {
> +			case 1:
> +				hwcaps.mask |= SNOR_HWCAPS_PP;
> +				break;
> +			case 4:
> +				hwcaps.mask |= SNOR_HWCAPS_PP_1_1_4 |
> +					       SNOR_HWCAPS_PP_1_4_4;
> +				break;
> +			default:
> +				dev_err(dev,
> +					"spi-tx-bus-width %d not supported\n",
> +					value);
> +				break;
> +			}
> +		}
> +
>  		ret = spi_nor_scan(nor, NULL, &hwcaps);
>  		if (ret)
>  			goto mutex_failed;
> 

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RE: [PATCH v2 1/2] mtd: fsl-quadspi: Update slave device hwcap based on mode provided in dtsi file

[Yogesh Narayan Gaur]

Hi Cyrille,

> -----Original Message-----
> From: Cyrille Pitchen [mailto:cyrille.pitchen@wedev4u.fr]
> Sent: Tuesday, February 06, 2018 2:19 AM
> To: Yogesh Narayan Gaur <yogeshnarayan.gaur@nxp.com>; linux-
> mtd@lists.infradead.org; devicetree@vger.kernel.org; robh@kernel.org;
> mark.rutland@arm.com; shawnguo@kernel.org
> Cc: linux-arm-kernel@lists.infradead.org; boris.brezillon@free-electrons.com;
> computersforpeace@gmail.com; Han Xu <han.xu@nxp.com>;
> festevam@gmail.com; Prabhakar Kushwaha <prabhakar.kushwaha@nxp.com>;
> Suresh Gupta <suresh.gupta@nxp.com>
> Subject: Re: [PATCH v2 1/2] mtd: fsl-quadspi: Update slave device hwcap based
> on mode provided in dtsi file
> 
> Hi Yogesh,
> 
> Le 02/02/2018 à 06:31, Yogesh Gaur a écrit :
> > FSL QuadSPI controller supports Single, dual, quad modes of operation.
> > Mode information is available via "spi-tx-bus-width" and
> > "spi-rx-bus-width" nodes of device tree for the connected slave device.
> >
> > Update read and write hwcap capability for slave device by reading
> > "spi-rx-bus-width" and "spi-tx-bus-width" respectively.
> > Assign hwcaps mask to minimal caps for the slave node i.e.
> > 	SNOR_HWCAPS_READ | SNOR_HWCAPS_PP
> >
> > If value not provided in device tree file, then fallback to default
> > mode i.e. SNOR_HWCAPS_READ_1_1_4 and SNOR_HWCAPS_PP.
> >
> > Signed-off-by: Prabhakar Kushwaha <prabhakar.kushwaha@nxp.com>
> > Signed-off-by: Yogesh Gaur <yogeshnarayan.gaur@nxp.com>
> > ---
> > Changes for v2:
> > - None
> >
> >  drivers/mtd/spi-nor/fsl-quadspi.c | 56
> > +++++++++++++++++++++++++++++++++++----
> >  1 file changed, 51 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/mtd/spi-nor/fsl-quadspi.c
> > b/drivers/mtd/spi-nor/fsl-quadspi.c
> > index b9c5918..1503e0c 100644
> > --- a/drivers/mtd/spi-nor/fsl-quadspi.c
> > +++ b/drivers/mtd/spi-nor/fsl-quadspi.c
> > @@ -994,17 +994,14 @@ static void fsl_qspi_unprep(struct spi_nor *nor,
> > enum spi_nor_ops ops)
> >
> >  static int fsl_qspi_probe(struct platform_device *pdev)  {
> > -	const struct spi_nor_hwcaps hwcaps = {
> > -		.mask = SNOR_HWCAPS_READ_1_1_4 |
> > -			SNOR_HWCAPS_PP,
> > -	};
> > +	struct spi_nor_hwcaps hwcaps;
> >  	struct device_node *np = pdev->dev.of_node;
> >  	struct device *dev = &pdev->dev;
> >  	struct fsl_qspi *q;
> >  	struct resource *res;
> >  	struct spi_nor *nor;
> >  	struct mtd_info *mtd;
> > -	int ret, i = 0;
> > +	int ret, i = 0, value;
> >
> >  	q = devm_kzalloc(dev, sizeof(*q), GFP_KERNEL);
> >  	if (!q)
> > @@ -1077,6 +1074,10 @@ static int fsl_qspi_probe(struct
> > platform_device *pdev)
> >
> >  	/* iterate the subnodes. */
> >  	for_each_available_child_of_node(dev->of_node, np) {
> > +		/* Reset hwcaps mask to minimal caps for the slave node. */
> > +		hwcaps.mask = SNOR_HWCAPS_READ | SNOR_HWCAPS_PP;
> > +		value = 0;
> > +
> >  		/* skip the holes */
> >  		if (!q->has_second_chip)
> >  			i *= 2;
> > @@ -1106,6 +1107,51 @@ static int fsl_qspi_probe(struct platform_device
> *pdev)
> >  		/* set the chip address for READID */
> >  		fsl_qspi_set_base_addr(q, nor);
> >
> > +		/*
> > +		 * If spi-rx-bus-width and spi-tx-bus-width not defined assign
> > +		 * default hardware capabilities SNOR_HWCAPS_READ_1_1_4
> and
> > +		 * SNOR_HWCAPS_PP supported by the Quad-SPI controller.
> > +		 */
> > +		if (!of_property_read_u32(np, "spi-rx-bus-width", &value)) {
> > +			switch (value) {
> > +			case 1:
> > +				hwcaps.mask |= SNOR_HWCAPS_READ |
> > +					       SNOR_HWCAPS_READ_FAST;
> > +				break;
> > +			case 2:
> > +				hwcaps.mask |= SNOR_HWCAPS_READ_1_1_2
> |
> > +					       SNOR_HWCAPS_READ_1_2_2;
> 
> I guess there is a misunderstanding in the meaning of spi-rx-bus-width and spi-
> tx-bus_width.
> 
> spi-rx-bus-width = <N>, resp. spi-tx-bus-width = <N>, means the SPI controller
> can receive, resp. send, data on N I/O Lines.
> 
> Then let's take the example of some Fast Read X-Y-Z command:
> 
> the op code is *sent* on X I/O lines: you need to check spi-tx-bus-width the
> address/mode/dummy bits are *sent* on Y I/O lines: check spi-tx-bus-width too
> the data bits are *received* on Z I/O lines: check spi-rx-bus_width.
> 
> > +				break;
> > +			case 4:
> > +				hwcaps.mask |= SNOR_HWCAPS_READ_1_1_4
> |
> > +					       SNOR_HWCAPS_READ_1_4_4;
> 
> The same here: to allow SPI 1-4-4, you have to check that spi-tx-bus-width == 4.
> 
> So your usage of spi-{tx|rx}-bus-width is not consistent with the usage done in
> the SPI subsystem. Please have a look at drivers/mtd/devices/m25p80.c,
> especially how the SPI_RX_QUAD and SPI_TX_QUAD flags are used in the
> m25p_probe() function to have a better idea of how it should work.
> 
> Also have a look at of_spi_parse_dt() in drivers/spi/spi.c, to figure out how the
> SPI_{TX|RX}_{DUAL|QUAD} flags are set according to the spi-{tx|rx}-bus-width
> DT properties.
> 
Thanks for review, would incorporate your review comments and would have usage of spi-{rx/tx}-bus-width as being done in SPI subsystem.

> > +				break;
> > +			default:
> > +				dev_err(dev,
> > +					"spi-rx-bus-width %d not supported\n",
> > +					value);
> > +				break;
> > +			}
> > +		} else
> > +			hwcaps.mask |= SNOR_HWCAPS_READ_1_1_4;
> 
> Not sure whether it passes checkpatch, you may have to add { } for the else
> statement even if there is a single line as the if statement use { }.
> 
I have run ' ./scripts/checkpatch.pl' present in linux-mtd code base and it hasn't reported any warning or error messages.
Meanwhile, would add {} braces for this else statement also.

--
Regards
Yogesh Gaur.

> Personally I don't mind that much. Please just check that your patch passes
> checkpatch verification and it will be okay for me :)
> 
> Best regards,
> 
> Cyrille
> 
> > +
> > +		if (!of_property_read_u32(np, "spi-tx-bus-width", &value)) {
> > +			switch (value) {
> > +			case 1:
> > +				hwcaps.mask |= SNOR_HWCAPS_PP;
> > +				break;
> > +			case 4:
> > +				hwcaps.mask |= SNOR_HWCAPS_PP_1_1_4 |
> > +					       SNOR_HWCAPS_PP_1_4_4;
> > +				break;
> > +			default:
> > +				dev_err(dev,
> > +					"spi-tx-bus-width %d not supported\n",
> > +					value);
> > +				break;
> > +			}
> > +		}
> > +
> >  		ret = spi_nor_scan(nor, NULL, &hwcaps);
> >  		if (ret)
> >  			goto mutex_failed;
> >