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[PATCH v2 1/5] mtd: spi-nor: notify (Q)SPI controller about protocol change

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  [PATCH v2 1/5] mtd: spi-nor: notify (Q)SPI controller about protocol change Cyrille Pitchen <cyrille.pitchen@atmel.com> - 2015-07-22 15:20 +0200
    Re: [PATCH v2 1/5] mtd: spi-nor: notify (Q)SPI controller about protocol change Marek Vasut <marex@denx.de> - 2015-07-22 16:00 +0200
      Re: [PATCH v2 1/5] mtd: spi-nor: notify (Q)SPI controller about protocol  change Cyrille Pitchen <cyrille.pitchen@atmel.com> - 2015-07-22 18:30 +0200
        Re: [PATCH v2 1/5] mtd: spi-nor: notify (Q)SPI controller about protocol change Marek Vasut <marex@denx.de> - 2015-07-23 09:10 +0200

#1189907 — [PATCH v2 1/5] mtd: spi-nor: notify (Q)SPI controller about protocol change

Once the Quad SPI mode has been enabled on a Micron flash memory, this
device expects ALL the following commands to use the SPI 4-4-4 protocol.
The (Q)SPI controller needs to be notified about the protocol change so it
can adapt and keep on dialoging with the Micron memory.

Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
---
 drivers/mtd/spi-nor/spi-nor.c | 17 +++++++++++++++++
 include/linux/mtd/spi-nor.h   | 13 +++++++++++++
 2 files changed, 30 insertions(+)

diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
index d78831b4422b..93627d4e6be8 100644
--- a/drivers/mtd/spi-nor/spi-nor.c
+++ b/drivers/mtd/spi-nor/spi-nor.c
@@ -163,6 +163,18 @@ static inline int write_disable(struct spi_nor *nor)
 	return nor->write_reg(nor, SPINOR_OP_WRDI, NULL, 0, 0);
 }
 
+/*
+ * Notify the (Q)SPI controller about the new protocol to be used.
+ */
+static inline int spi_nor_set_protocol(struct spi_nor *nor,
+				       enum spi_protocol proto)
+{
+	if (nor->set_protocol)
+		return nor->set_protocol(nor, proto);
+
+	return 0;
+}
+
 static inline struct spi_nor *mtd_to_spi_nor(struct mtd_info *mtd)
 {
 	return mtd->priv;
@@ -943,6 +955,11 @@ static int micron_quad_enable(struct spi_nor *nor)
 		return ret;
 	}
 
+	/* switch protocol to Quad CMD 4-4-4 */
+	ret = spi_nor_set_protocol(nor, SPI_PROTO_4_4_4);
+	if (ret)
+		return ret;
+
 	ret = spi_nor_wait_till_ready(nor);
 	if (ret)
 		return ret;
diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h
index e5409524bb0a..1bf6f11310ef 100644
--- a/include/linux/mtd/spi-nor.h
+++ b/include/linux/mtd/spi-nor.h
@@ -87,6 +87,16 @@ enum read_mode {
 	SPI_NOR_QUAD,
 };
 
+enum spi_protocol {
+	SPI_PROTO_1_1_1,	/* SPI */
+	SPI_PROTO_1_1_2,	/* Dual Output */
+	SPI_PROTO_1_1_4,	/* Quad Output */
+	SPI_PROTO_1_2_2,	/* Dual IO */
+	SPI_PROTO_1_4_4,	/* Quad IO */
+	SPI_PROTO_2_2_2,	/* Dual Command */
+	SPI_PROTO_4_4_4,	/* Quad Command */
+};
+
 /**
  * struct spi_nor_xfer_cfg - Structure for defining a Serial Flash transfer
  * @wren:		command for "Write Enable", or 0x00 for not required
@@ -149,6 +159,7 @@ enum spi_nor_option_flags {
  *			read/write/erase/lock/unlock operations
  * @read_xfer:		[OPTIONAL] the read fundamental primitive
  * @write_xfer:		[OPTIONAL] the writefundamental primitive
+ * @set_protocol:	[OPTIONAL] notify about protocol change
  * @read_reg:		[DRIVER-SPECIFIC] read out the register
  * @write_reg:		[DRIVER-SPECIFIC] write data to the register
  * @read:		[DRIVER-SPECIFIC] read data from the SPI NOR
@@ -185,6 +196,8 @@ struct spi_nor {
 	int (*write_reg)(struct spi_nor *nor, u8 opcode, u8 *buf, int len,
 			int write_enable);
 
+	int (*set_protocol)(struct spi_nor *nor, enum spi_protocol proto);
+
 	int (*read)(struct spi_nor *nor, loff_t from,
 			size_t len, size_t *retlen, u_char *read_buf);
 	void (*write)(struct spi_nor *nor, loff_t to,
-- 
1.8.2.2

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#1189966

On Wednesday, July 22, 2015 at 03:17:06 PM, Cyrille Pitchen wrote:
> Once the Quad SPI mode has been enabled on a Micron flash memory, this
> device expects ALL the following commands to use the SPI 4-4-4 protocol.
> The (Q)SPI controller needs to be notified about the protocol change so it
> can adapt and keep on dialoging with the Micron memory.
> 
> Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
> ---
>  drivers/mtd/spi-nor/spi-nor.c | 17 +++++++++++++++++
>  include/linux/mtd/spi-nor.h   | 13 +++++++++++++
>  2 files changed, 30 insertions(+)
> 
> diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
> index d78831b4422b..93627d4e6be8 100644
> --- a/drivers/mtd/spi-nor/spi-nor.c
> +++ b/drivers/mtd/spi-nor/spi-nor.c
> @@ -163,6 +163,18 @@ static inline int write_disable(struct spi_nor *nor)
>  	return nor->write_reg(nor, SPINOR_OP_WRDI, NULL, 0, 0);
>  }
> 
> +/*
> + * Notify the (Q)SPI controller about the new protocol to be used.

Hi!

Can you please just reword this a little, so that it is absolutelly clear
even to the less bright of us (like me) that this is a notification coming
from the upper layers (ie. the spi-nor framework) toward the hardware ?

> + */
> +static inline int spi_nor_set_protocol(struct spi_nor *nor,
> +				       enum spi_protocol proto)
> +{
> +	if (nor->set_protocol)
> +		return nor->set_protocol(nor, proto);
> +
> +	return 0;
> +}
> +
>  static inline struct spi_nor *mtd_to_spi_nor(struct mtd_info *mtd)
>  {
>  	return mtd->priv;

[...]

Best regards,
Marek Vasut
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#1190095 — Re: [PATCH v2 1/5] mtd: spi-nor: notify (Q)SPI controller about protocol change

Hi Marek,

Le 22/07/2015 15:41, Marek Vasut a écrit :
> On Wednesday, July 22, 2015 at 03:17:06 PM, Cyrille Pitchen wrote:
>> Once the Quad SPI mode has been enabled on a Micron flash memory, this
>> device expects ALL the following commands to use the SPI 4-4-4 protocol.
>> The (Q)SPI controller needs to be notified about the protocol change so it
>> can adapt and keep on dialoging with the Micron memory.
>>
>> Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
>> ---
>>  drivers/mtd/spi-nor/spi-nor.c | 17 +++++++++++++++++
>>  include/linux/mtd/spi-nor.h   | 13 +++++++++++++
>>  2 files changed, 30 insertions(+)
>>
>> diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
>> index d78831b4422b..93627d4e6be8 100644
>> --- a/drivers/mtd/spi-nor/spi-nor.c
>> +++ b/drivers/mtd/spi-nor/spi-nor.c
>> @@ -163,6 +163,18 @@ static inline int write_disable(struct spi_nor *nor)
>>  	return nor->write_reg(nor, SPINOR_OP_WRDI, NULL, 0, 0);
>>  }
>>
>> +/*
>> + * Notify the (Q)SPI controller about the new protocol to be used.
> 
> Hi!
> 
> Can you please just reword this a little, so that it is absolutelly clear
> even to the less bright of us (like me) that this is a notification coming
> from the upper layers (ie. the spi-nor framework) toward the hardware ?
> 
Sure, no problem! what about the following?

/*
 * Let the spi-nor framework notify lower layers, especially the driver of the
 * (Q)SPI controller, about the new protocol to be used. Indeed, once the
 * spi-nor framework has sent manufacturer specific commands to a memory to
 * enable its Quad SPI mode, it should immediately after tell the QSPI
 * controller to use the very same Quad SPI protocol as expected by the memory.
 */

>> + */
>> +static inline int spi_nor_set_protocol(struct spi_nor *nor,
>> +				       enum spi_protocol proto)
>> +{
>> +	if (nor->set_protocol)
>> +		return nor->set_protocol(nor, proto);
>> +
>> +	return 0;
>> +}
>> +
>>  static inline struct spi_nor *mtd_to_spi_nor(struct mtd_info *mtd)
>>  {
>>  	return mtd->priv;
> 
> [...]
> 
> Best regards,
> Marek Vasut
> 
Best regards,

Cyrille
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#1190671

On Wednesday, July 22, 2015 at 06:25:20 PM, Cyrille Pitchen wrote:
> Hi Marek,
> 
> Le 22/07/2015 15:41, Marek Vasut a écrit :
> > On Wednesday, July 22, 2015 at 03:17:06 PM, Cyrille Pitchen wrote:
> >> Once the Quad SPI mode has been enabled on a Micron flash memory, this
> >> device expects ALL the following commands to use the SPI 4-4-4 protocol.
> >> The (Q)SPI controller needs to be notified about the protocol change so
> >> it can adapt and keep on dialoging with the Micron memory.
> >> 
> >> Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
> >> ---
> >> 
> >>  drivers/mtd/spi-nor/spi-nor.c | 17 +++++++++++++++++
> >>  include/linux/mtd/spi-nor.h   | 13 +++++++++++++
> >>  2 files changed, 30 insertions(+)
> >> 
> >> diff --git a/drivers/mtd/spi-nor/spi-nor.c
> >> b/drivers/mtd/spi-nor/spi-nor.c index d78831b4422b..93627d4e6be8 100644
> >> --- a/drivers/mtd/spi-nor/spi-nor.c
> >> +++ b/drivers/mtd/spi-nor/spi-nor.c
> >> @@ -163,6 +163,18 @@ static inline int write_disable(struct spi_nor
> >> *nor)
> >> 
> >>  	return nor->write_reg(nor, SPINOR_OP_WRDI, NULL, 0, 0);
> >>  
> >>  }
> >> 
> >> +/*
> >> + * Notify the (Q)SPI controller about the new protocol to be used.
> > 
> > Hi!
> > 
> > Can you please just reword this a little, so that it is absolutelly clear
> > even to the less bright of us (like me) that this is a notification
> > coming from the upper layers (ie. the spi-nor framework) toward the
> > hardware ?
> 
> Sure, no problem! what about the following?
> 
> /*
>  * Let the spi-nor framework notify lower layers, especially the driver of
> the * (Q)SPI controller, about the new protocol to be used. Indeed, once
> the * spi-nor framework has sent manufacturer specific commands to a
> memory to * enable its Quad SPI mode, it should immediately after tell the
> QSPI * controller to use the very same Quad SPI protocol as expected by
> the memory. */

Sure, excellent, thanks ! :-)
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