From: Peng Fan <peng.fan@nxp.com>

spi nor flash needs power supply to work properly. The power supply
maybe software controllable per board design. So add the support
for an optional vcc-supply regulator.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
---
 drivers/mtd/spi-nor/core.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c
index 9d6e85bf227b..0449afe6bb20 100644
--- a/drivers/mtd/spi-nor/core.c
+++ b/drivers/mtd/spi-nor/core.c
@@ -17,6 +17,7 @@
 #include <linux/mtd/spi-nor.h>
 #include <linux/mutex.h>
 #include <linux/of_platform.h>
+#include <linux/regulator/consumer.h>
 #include <linux/sched/task_stack.h>
 #include <linux/sizes.h>
 #include <linux/slab.h>
@@ -3462,6 +3463,10 @@ int spi_nor_scan(struct spi_nor *nor, const char *name,
 	if (!nor->bouncebuf)
 		return -ENOMEM;
 
+	ret = devm_regulator_get_enable_optional(dev, "vcc");
+	if (ret)
+		return ret;
+
 	ret = spi_nor_hw_reset(nor);
 	if (ret)
 		return ret;

-- 
2.37.1

On Fri, Sep 20, 2024 at 04:54:07PM +0800, Peng Fan (OSS) wrote:
> From: Peng Fan <peng.fan@nxp.com>
>
> spi nor flash needs power supply to work properly. The power supply
> maybe software controllable per board design. So add the support
> for an optional vcc-supply regulator.
>
> Signed-off-by: Peng Fan <peng.fan@nxp.com>
> ---
>  drivers/mtd/spi-nor/core.c | 5 +++++
>  1 file changed, 5 insertions(+)
>
> diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c
> index 9d6e85bf227b..0449afe6bb20 100644
> --- a/drivers/mtd/spi-nor/core.c
> +++ b/drivers/mtd/spi-nor/core.c
> @@ -17,6 +17,7 @@
>  #include <linux/mtd/spi-nor.h>
>  #include <linux/mutex.h>
>  #include <linux/of_platform.h>
> +#include <linux/regulator/consumer.h>
>  #include <linux/sched/task_stack.h>
>  #include <linux/sizes.h>
>  #include <linux/slab.h>
> @@ -3462,6 +3463,10 @@ int spi_nor_scan(struct spi_nor *nor, const char *name,
>  	if (!nor->bouncebuf)
>  		return -ENOMEM;
>
> +	ret = devm_regulator_get_enable_optional(dev, "vcc");
> +	if (ret)
> +		return ret;
> +

I think devm_regulator_get_enable_optional() should be called in
spi_nor_probe(). spi_nor_scan() is public API, which may call many time.
That will cause regulartor reference counter wrong.

Frank

>  	ret = spi_nor_hw_reset(nor);
>  	if (ret)
>  		return ret;
>
> --
> 2.37.1
>

On 24-09-20, Peng Fan (OSS) wrote:
> From: Peng Fan <peng.fan@nxp.com>
> 
> spi nor flash needs power supply to work properly. The power supply
> maybe software controllable per board design. So add the support
> for an optional vcc-supply regulator.
> 
> Signed-off-by: Peng Fan <peng.fan@nxp.com>
> ---
>  drivers/mtd/spi-nor/core.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c
> index 9d6e85bf227b..0449afe6bb20 100644
> --- a/drivers/mtd/spi-nor/core.c
> +++ b/drivers/mtd/spi-nor/core.c
> @@ -17,6 +17,7 @@
>  #include <linux/mtd/spi-nor.h>
>  #include <linux/mutex.h>
>  #include <linux/of_platform.h>
> +#include <linux/regulator/consumer.h>
>  #include <linux/sched/task_stack.h>
>  #include <linux/sizes.h>
>  #include <linux/slab.h>
> @@ -3462,6 +3463,10 @@ int spi_nor_scan(struct spi_nor *nor, const char *name,
>  	if (!nor->bouncebuf)
>  		return -ENOMEM;
>  
> +	ret = devm_regulator_get_enable_optional(dev, "vcc");
> +	if (ret)

This returns -ENODEV if no regulator was specified. In general all
SPI-NOR devices need a VCC supply, so don't use the regulator optional
API here, please check the regulator API doc.

In contrast to that the dt-bindings should have the vcc-supply as
optional to not cause a regression for exisiting systems.

Regards,
  Marco

> +		return ret;
> +
>  	ret = spi_nor_hw_reset(nor);
>  	if (ret)
>  		return ret;
> 
> -- 
> 2.37.1
> 
> 
>