[PATCH 0/2] Implement guideline when NAND, NOR arbitration is enabled

[PATCH 0/2] Implement guideline when NAND, NOR arbitration is enabled

[Kalyan Kinthada]

When the arbitration between NOR and NAND flash is enabled
the <FORCE_CSX> field bit[21] in the Data Flash Control Register
needs to be set to 1 according to guidleine GL-5830741.

This patch series contain the following patches:
* Patch 1: "dt-bindings: mtd: pxa3xx: Add "marvell,nand-force-csx" compatible string"
  * New binding is introduced to implement the guildeline GL-5830741 which will
    be activated in the appropriate device tree files.

* Patch 2: "mtd: nand: pxa3xx: Handle "marvell,nand-force-csx" compatible string"
  * Set the FORCE_CSX bit in Data Flash Control Register if "marvell,nand-force-csx"
    compatible string is activated in the device tree.

-----------------
Kalyan Kinthada (2):
[PATCH 1/2] dt-bindings: mtd: pxa3xx: Add "marvell,nand-force-csx" compatible string
[PATCH 2/2] mtd: nand: pxa3xx: Handle "marvell,nand-force-csx" compatible string

 Documentation/devicetree/bindings/mtd/pxa3xx-nand.txt | 1 +
 drivers/mtd/nand/pxa3xx_nand.c                        | 6 ++++++
 include/linux/platform_data/mtd-nand-pxa3xx.h         | 3 +++
 3 files changed, 10 insertions(+)

-- 
2.14.1

[PATCH 1/2] dt-bindings: mtd: pxa3xx: Add "marvell,nand-force-csx" compatible string

[Kalyan Kinthada]

When the arbitration between NOR and NAND flash is enabled
the <FORCE_CSX> field bit[21] in the Data Flash Control Register
needs to be set to 1 according to guidleine GL-5830741.

This patch introduces a new compatible string "marvell,nand-force-csx"
which is activated through device tree to implement the guideline
GL-5830741.

Signed-off-by: Kalyan Kinthada <kalyan.kinthada@alliedtelesis.co.nz>
---
 Documentation/devicetree/bindings/mtd/pxa3xx-nand.txt | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Documentation/devicetree/bindings/mtd/pxa3xx-nand.txt b/Documentation/devicetree/bindings/mtd/pxa3xx-nand.txt
index d9b655f11048..157ca7efa3d3 100644
--- a/Documentation/devicetree/bindings/mtd/pxa3xx-nand.txt
+++ b/Documentation/devicetree/bindings/mtd/pxa3xx-nand.txt
@@ -20,6 +20,7 @@ Optional properties:
 				not present false
  - nand-ecc-strength:           number of bits to correct per ECC step
  - nand-ecc-step-size:          number of data bytes covered by a single ECC step
+ - marvell,nand-force-csx:      Set to implement guideline when arbitration of NAND and NOR flash is enabled.
 
 The following ECC strength and step size are currently supported:
 
-- 
2.14.1

[PATCH 2/2] mtd: nand: pxa3xx: Handle "marvell,nand-force-csx" compatible string

[Kalyan Kinthada]

When the arbitration between NOR and NAND flash is enabled
the <FORCE_CSX> field bit[21] in the Data Flash Control Register
needs to be set to 1 according to guidleine GL-5830741.

This commit sets the FORCE_CSX bit to 1 if the compatible
string "marvell,nand-force-csx" is enabled in the device tree
of the corresponding boards.

Signed-off-by: Kalyan Kinthada <kalyan.kinthada@alliedtelesis.co.nz>
---
 drivers/mtd/nand/pxa3xx_nand.c                | 6 ++++++
 include/linux/platform_data/mtd-nand-pxa3xx.h | 3 +++
 2 files changed, 9 insertions(+)

diff --git a/drivers/mtd/nand/pxa3xx_nand.c b/drivers/mtd/nand/pxa3xx_nand.c
index 85cff68643e0..4ad1f0601930 100644
--- a/drivers/mtd/nand/pxa3xx_nand.c
+++ b/drivers/mtd/nand/pxa3xx_nand.c
@@ -68,6 +68,7 @@
 #define NDCR_PAGE_SZ		(0x1 << 24)
 #define NDCR_NCSX		(0x1 << 23)
 #define NDCR_ND_MODE		(0x3 << 21)
+#define NDCR_FORCE_CSX		(0x1 << 21)
 #define NDCR_NAND_MODE   	(0x0)
 #define NDCR_CLR_PG_CNT		(0x1 << 20)
 #define NFCV1_NDCR_ARB_CNTL	(0x1 << 19)
@@ -1464,6 +1465,7 @@ static int pxa3xx_nand_config_ident(struct pxa3xx_nand_info *info)
 	info->chunk_size = PAGE_CHUNK_SIZE;
 	info->reg_ndcr = 0x0; /* enable all interrupts */
 	info->reg_ndcr |= (pdata->enable_arbiter) ? NDCR_ND_ARB_EN : 0;
+	info->reg_ndcr |= (pdata->force_csx) ? NDCR_FORCE_CSX : 0;
 	info->reg_ndcr |= NDCR_RD_ID_CNT(READ_ID_BYTES);
 	info->reg_ndcr |= NDCR_SPARE_EN;
 
@@ -1498,6 +1500,7 @@ static void pxa3xx_nand_detect_config(struct pxa3xx_nand_info *info)
 	info->reg_ndcr = ndcr &
 		~(NDCR_INT_MASK | NDCR_ND_ARB_EN | NFCV1_NDCR_ARB_CNTL);
 	info->reg_ndcr |= (pdata->enable_arbiter) ? NDCR_ND_ARB_EN : 0;
+	info->reg_ndcr |= (pdata->force_csx) ? NDCR_FORCE_CSX : 0;
 	info->ndtr0cs0 = nand_readl(info, NDTR0CS0);
 	info->ndtr1cs0 = nand_readl(info, NDTR1CS0);
 }
@@ -1936,6 +1939,9 @@ static int pxa3xx_nand_probe_dt(struct platform_device *pdev)
 		pdata->enable_arbiter = 1;
 	if (of_get_property(np, "marvell,nand-keep-config", NULL))
 		pdata->keep_config = 1;
+	if (of_get_property(np, "marvell,nand-force-csx", NULL))
+		/* Ref#: GL-5830741 */
+		pdata->force_csx = 1;
 	of_property_read_u32(np, "num-cs", &pdata->num_cs);
 
 	pdev->dev.platform_data = pdata;
diff --git a/include/linux/platform_data/mtd-nand-pxa3xx.h b/include/linux/platform_data/mtd-nand-pxa3xx.h
index 394d15597dc7..e7f2c8647c0e 100644
--- a/include/linux/platform_data/mtd-nand-pxa3xx.h
+++ b/include/linux/platform_data/mtd-nand-pxa3xx.h
@@ -28,6 +28,9 @@ struct pxa3xx_nand_platform_data {
 	/* allow platform code to keep OBM/bootloader defined NFC config */
 	int	keep_config;
 
+	/* Force chip select false on busy */
+	int	force_csx;
+
 	/* indicate how many chip selects will be used */
 	int	num_cs;
 
-- 
2.14.1

Re: [PATCH 2/2] mtd: nand: pxa3xx: Handle "marvell, nand-force-csx" compatible string

[Miquel RAYNAL]

Hi Kalyan,

On Tue, 26 Sep 2017 17:17:00 +1300
Kalyan Kinthada <kalyan.kinthada@alliedtelesis.co.nz> wrote:

> When the arbitration between NOR and NAND flash is enabled
> the <FORCE_CSX> field bit[21] in the Data Flash Control Register
> needs to be set to 1 according to guidleine GL-5830741.

I do agree, the driver lacks the support of this bit, which
looks important when you effectively use the arbiter.
Nevertheless:

- On PXA (marvell,pxa3xx-nand compatible), there is a ND_ARB_EN bit to
  enable or disable the arbiter, but there is no FORCE_CSX bit (bit 21
  of NDCR, the so called Control Register, is reserved).
- On Armada (marvell,armada370-nand), there is a FORCE_CSX bit, but
  there is no ND_ARB_EN bit in the NDCR (moved to system registers) and
  the arbitration is always enabled by default.

I guess you should always set the FORCE_CSX bit when using the armada
compatible, because it is harmless, right? Thus, you could get rid
of the new DT property.

Thank you,
Miquèl

> 
> This commit sets the FORCE_CSX bit to 1 if the compatible
> string "marvell,nand-force-csx" is enabled in the device tree
> of the corresponding boards.
> 
> Signed-off-by: Kalyan Kinthada <kalyan.kinthada@alliedtelesis.co.nz>
> ---
>  drivers/mtd/nand/pxa3xx_nand.c                | 6 ++++++
>  include/linux/platform_data/mtd-nand-pxa3xx.h | 3 +++
>  2 files changed, 9 insertions(+)
> 
> diff --git a/drivers/mtd/nand/pxa3xx_nand.c
> b/drivers/mtd/nand/pxa3xx_nand.c index 85cff68643e0..4ad1f0601930
> 100644 --- a/drivers/mtd/nand/pxa3xx_nand.c
> +++ b/drivers/mtd/nand/pxa3xx_nand.c
> @@ -68,6 +68,7 @@
>  #define NDCR_PAGE_SZ		(0x1 << 24)
>  #define NDCR_NCSX		(0x1 << 23)
>  #define NDCR_ND_MODE		(0x3 << 21)
> +#define NDCR_FORCE_CSX		(0x1 << 21)
>  #define NDCR_NAND_MODE   	(0x0)
>  #define NDCR_CLR_PG_CNT		(0x1 << 20)
>  #define NFCV1_NDCR_ARB_CNTL	(0x1 << 19)
> @@ -1464,6 +1465,7 @@ static int pxa3xx_nand_config_ident(struct
> pxa3xx_nand_info *info) info->chunk_size = PAGE_CHUNK_SIZE;
>  	info->reg_ndcr = 0x0; /* enable all interrupts */
>  	info->reg_ndcr |= (pdata->enable_arbiter) ? NDCR_ND_ARB_EN :
> 0;
> +	info->reg_ndcr |= (pdata->force_csx) ? NDCR_FORCE_CSX : 0;
>  	info->reg_ndcr |= NDCR_RD_ID_CNT(READ_ID_BYTES);
>  	info->reg_ndcr |= NDCR_SPARE_EN;
>  
> @@ -1498,6 +1500,7 @@ static void pxa3xx_nand_detect_config(struct
> pxa3xx_nand_info *info) info->reg_ndcr = ndcr &
>  		~(NDCR_INT_MASK | NDCR_ND_ARB_EN |
> NFCV1_NDCR_ARB_CNTL); info->reg_ndcr |= (pdata->enable_arbiter) ?
> NDCR_ND_ARB_EN : 0;
> +	info->reg_ndcr |= (pdata->force_csx) ? NDCR_FORCE_CSX : 0;
>  	info->ndtr0cs0 = nand_readl(info, NDTR0CS0);
>  	info->ndtr1cs0 = nand_readl(info, NDTR1CS0);
>  }
> @@ -1936,6 +1939,9 @@ static int pxa3xx_nand_probe_dt(struct
> platform_device *pdev) pdata->enable_arbiter = 1;
>  	if (of_get_property(np, "marvell,nand-keep-config", NULL))
>  		pdata->keep_config = 1;
> +	if (of_get_property(np, "marvell,nand-force-csx", NULL))
> +		/* Ref#: GL-5830741 */
> +		pdata->force_csx = 1;
>  	of_property_read_u32(np, "num-cs", &pdata->num_cs);
>  
>  	pdev->dev.platform_data = pdata;
> diff --git a/include/linux/platform_data/mtd-nand-pxa3xx.h
> b/include/linux/platform_data/mtd-nand-pxa3xx.h index
> 394d15597dc7..e7f2c8647c0e 100644 ---
> a/include/linux/platform_data/mtd-nand-pxa3xx.h +++
> b/include/linux/platform_data/mtd-nand-pxa3xx.h @@ -28,6 +28,9 @@
> struct pxa3xx_nand_platform_data { /* allow platform code to keep
> OBM/bootloader defined NFC config */ int	keep_config;
>  
> +	/* Force chip select false on busy */
> +	int	force_csx;
> +
>  	/* indicate how many chip selects will be used */
>  	int	num_cs;
>  



-- 
Miquel Raynal, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com

Re: [PATCH 2/2] mtd: nand: pxa3xx: Handle "marvell, nand-force-csx" compatible string

[Kalyan Kinthada]

On 26/09/17 20:18, Miquel RAYNAL wrote:
> Hi Kalyan,
>
> On Tue, 26 Sep 2017 17:17:00 +1300
> Kalyan Kinthada <kalyan.kinthada@alliedtelesis.co.nz> wrote:
>
>> When the arbitration between NOR and NAND flash is enabled
>> the <FORCE_CSX> field bit[21] in the Data Flash Control Register
>> needs to be set to 1 according to guidleine GL-5830741.
> I do agree, the driver lacks the support of this bit, which
> looks important when you effectively use the arbiter.
> Nevertheless:
>
> - On PXA (marvell,pxa3xx-nand compatible), there is a ND_ARB_EN bit to
>    enable or disable the arbiter, but there is no FORCE_CSX bit (bit 21
>    of NDCR, the so called Control Register, is reserved).
> - On Armada (marvell,armada370-nand), there is a FORCE_CSX bit, but
>    there is no ND_ARB_EN bit in the NDCR (moved to system registers) and
>    the arbitration is always enabled by default.
>
> I guess you should always set the FORCE_CSX bit when using the armada
> compatible, because it is harmless, right? Thus, you could get rid
> of the new DT property.
Ok. I will make changes to the driver to set FORCE_CSX bit for all
variants of ARMADA370 variants instead of creating a new compatible
string.

I will send a new patch. Kindly ignore these changes.
Thanks for your time Miquel.

Thank You,
Kalyan
>
> Thank you,
> Miquèl
>
>> This commit sets the FORCE_CSX bit to 1 if the compatible
>> string "marvell,nand-force-csx" is enabled in the device tree
>> of the corresponding boards.
>>
>> Signed-off-by: Kalyan Kinthada <kalyan.kinthada@alliedtelesis.co.nz>
>> ---
>>   drivers/mtd/nand/pxa3xx_nand.c                | 6 ++++++
>>   include/linux/platform_data/mtd-nand-pxa3xx.h | 3 +++
>>   2 files changed, 9 insertions(+)
>>
>> diff --git a/drivers/mtd/nand/pxa3xx_nand.c
>> b/drivers/mtd/nand/pxa3xx_nand.c index 85cff68643e0..4ad1f0601930
>> 100644 --- a/drivers/mtd/nand/pxa3xx_nand.c
>> +++ b/drivers/mtd/nand/pxa3xx_nand.c
>> @@ -68,6 +68,7 @@
>>   #define NDCR_PAGE_SZ		(0x1 << 24)
>>   #define NDCR_NCSX		(0x1 << 23)
>>   #define NDCR_ND_MODE		(0x3 << 21)
>> +#define NDCR_FORCE_CSX		(0x1 << 21)
>>   #define NDCR_NAND_MODE   	(0x0)
>>   #define NDCR_CLR_PG_CNT		(0x1 << 20)
>>   #define NFCV1_NDCR_ARB_CNTL	(0x1 << 19)
>> @@ -1464,6 +1465,7 @@ static int pxa3xx_nand_config_ident(struct
>> pxa3xx_nand_info *info) info->chunk_size = PAGE_CHUNK_SIZE;
>>   	info->reg_ndcr = 0x0; /* enable all interrupts */
>>   	info->reg_ndcr |= (pdata->enable_arbiter) ? NDCR_ND_ARB_EN :
>> 0;
>> +	info->reg_ndcr |= (pdata->force_csx) ? NDCR_FORCE_CSX : 0;
>>   	info->reg_ndcr |= NDCR_RD_ID_CNT(READ_ID_BYTES);
>>   	info->reg_ndcr |= NDCR_SPARE_EN;
>>   
>> @@ -1498,6 +1500,7 @@ static void pxa3xx_nand_detect_config(struct
>> pxa3xx_nand_info *info) info->reg_ndcr = ndcr &
>>   		~(NDCR_INT_MASK | NDCR_ND_ARB_EN |
>> NFCV1_NDCR_ARB_CNTL); info->reg_ndcr |= (pdata->enable_arbiter) ?
>> NDCR_ND_ARB_EN : 0;
>> +	info->reg_ndcr |= (pdata->force_csx) ? NDCR_FORCE_CSX : 0;
>>   	info->ndtr0cs0 = nand_readl(info, NDTR0CS0);
>>   	info->ndtr1cs0 = nand_readl(info, NDTR1CS0);
>>   }
>> @@ -1936,6 +1939,9 @@ static int pxa3xx_nand_probe_dt(struct
>> platform_device *pdev) pdata->enable_arbiter = 1;
>>   	if (of_get_property(np, "marvell,nand-keep-config", NULL))
>>   		pdata->keep_config = 1;
>> +	if (of_get_property(np, "marvell,nand-force-csx", NULL))
>> +		/* Ref#: GL-5830741 */
>> +		pdata->force_csx = 1;
>>   	of_property_read_u32(np, "num-cs", &pdata->num_cs);
>>   
>>   	pdev->dev.platform_data = pdata;
>> diff --git a/include/linux/platform_data/mtd-nand-pxa3xx.h
>> b/include/linux/platform_data/mtd-nand-pxa3xx.h index
>> 394d15597dc7..e7f2c8647c0e 100644 ---
>> a/include/linux/platform_data/mtd-nand-pxa3xx.h +++
>> b/include/linux/platform_data/mtd-nand-pxa3xx.h @@ -28,6 +28,9 @@
>> struct pxa3xx_nand_platform_data { /* allow platform code to keep
>> OBM/bootloader defined NFC config */ int	keep_config;
>>   
>> +	/* Force chip select false on busy */
>> +	int	force_csx;
>> +
>>   	/* indicate how many chip selects will be used */
>>   	int	num_cs;
>>   
>
>