[U-Boot] [PATCH 1/2] doc: README.fuse: Add an example on how to use the fuse API on mx6q

[U-Boot] [PATCH 1/2] doc: README.fuse: Add an example on how to use the fuse API on mx6q

[Fabio Estevam]

From: Fabio Estevam <fabio.estevam@freescale.com>

When using the fuse API in U-boot user must calculate the 'bank' and 'word' 
values. 

Provide a real example on how to calculate such values for the mx6q.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
---
 doc/README.fuse | 57 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 57 insertions(+)

diff --git a/doc/README.fuse b/doc/README.fuse
index 1bc91c4..aca1e5e 100644
--- a/doc/README.fuse
+++ b/doc/README.fuse
@@ -65,3 +65,60 @@ Configuration:
 
    CONFIG_CMD_FUSE
       Define this to enable the fuse commands.
+
+Example:
+
+For reading the MAC address fuses on a MX6Q:
+
+- The MAC address are stored in two fuse addresses (the fuse addresses are
+described in the Fusemap Descriptions table from the mx6q Reference Manual):
+
+0x620[31:0] - MAC_ADDR[31:0]
+0x630[15:0] - MAC_ADDR[47:32]
+
+In order to use the fuse API, we need to pass the bank and word values, which
+are calculated as below:
+
+Fuse address for the lower MAC address: 0x620
+Base address for the fuses: 0x400
+
+(0x620 - 0x400)/0x10 = 0x22 = 34 decimal
+
+As the fuses are arranged in banks of 8 words:
+
+34 / 8 = 4 and the remainder is 2, so in this case:
+
+bank = 4
+word = 2
+
+And the U-boot command would be:
+
+=> fuse read 4 2
+Reading bank 4:
+
+Word 0x00000002: 9f027772
+
+Doing the same for the upper MAC address:
+
+Fuse address for the upper MAC address: 0x630
+Base address for the fuses: 0x400
+
+(0x630 - 0x400)/0x10 = 0x23 = 35 decimal
+
+As the fuses are arranged in banks of 8 words:
+
+35 / 8 = 4 and the remainder is 3, so in this case:
+
+bank = 4
+word = 3
+
+And the U-boot command would be:
+
+=> fuse read 4 3
+Reading bank 4:
+
+Word 0x00000003: 00000004
+
+,which matches the ethaddr value:
+=> echo ${ethaddr}
+00:04:9f:02:77:72
-- 
1.8.1.2

[U-Boot] [PATCH 2/2] mx6sabre_common.h: Add CONFIG_CMD_FUSE support

[Fabio Estevam]

From: Fabio Estevam <fabio.estevam@freescale.com>

Add CONFIG_CMD_FUSE option, so that the fuse API can be used.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
---
 include/configs/mx6sabre_common.h | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/include/configs/mx6sabre_common.h b/include/configs/mx6sabre_common.h
index d52c9a8..63405aa 100644
--- a/include/configs/mx6sabre_common.h
+++ b/include/configs/mx6sabre_common.h
@@ -34,6 +34,11 @@
 
 #define CONFIG_MXC_UART
 
+#define CONFIG_CMD_FUSE
+#ifdef CONFIG_CMD_FUSE
+#define CONFIG_MXC_OCOTP
+#endif
+
 /* MMC Configs */
 #define CONFIG_FSL_ESDHC
 #define CONFIG_FSL_USDHC
-- 
1.8.1.2

[U-Boot] [PATCH 2/2] mx6sabre_common.h: Add CONFIG_CMD_FUSE support

[Benoît Thébaudeau]

Hi Fabio,

On Tuesday, December 17, 2013 9:03:41 PM, Fabio Estevam wrote:
> From: Fabio Estevam <fabio.estevam@freescale.com>
> 
> Add CONFIG_CMD_FUSE option, so that the fuse API can be used.
> 
> Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
> ---
>  include/configs/mx6sabre_common.h | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/include/configs/mx6sabre_common.h
> b/include/configs/mx6sabre_common.h
> index d52c9a8..63405aa 100644
> --- a/include/configs/mx6sabre_common.h
> +++ b/include/configs/mx6sabre_common.h
> @@ -34,6 +34,11 @@
>  
>  #define CONFIG_MXC_UART
>  
> +#define CONFIG_CMD_FUSE
> +#ifdef CONFIG_CMD_FUSE
> +#define CONFIG_MXC_OCOTP
> +#endif
> +
>  /* MMC Configs */
>  #define CONFIG_FSL_ESDHC
>  #define CONFIG_FSL_USDHC
> --
> 1.8.1.2

Reviewed-by: Beno?t Th?baudeau <benoit.thebaudeau@advansee.com>

Best regards,
Beno?t

[U-Boot] [PATCH 1/2] doc: README.fuse: Add an example on how to use the fuse API on mx6q

[Benoît Thébaudeau]

Hi Fabio,

On Tuesday, December 17, 2013 9:03:40 PM, Fabio Estevam wrote:
> From: Fabio Estevam <fabio.estevam@freescale.com>
> 
> When using the fuse API in U-boot user must calculate the 'bank' and 'word'
> values.
> 
> Provide a real example on how to calculate such values for the mx6q.
> 
> Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
> ---
>  doc/README.fuse | 57
>  +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 57 insertions(+)
> 
> diff --git a/doc/README.fuse b/doc/README.fuse
> index 1bc91c4..aca1e5e 100644
> --- a/doc/README.fuse
> +++ b/doc/README.fuse
> @@ -65,3 +65,60 @@ Configuration:
>  
>     CONFIG_CMD_FUSE
>        Define this to enable the fuse commands.
> +
> +Example:
> +
> +For reading the MAC address fuses on a MX6Q:
> +
> +- The MAC address are stored in two fuse addresses (the fuse addresses are
> +described in the Fusemap Descriptions table from the mx6q Reference Manual):
> +
> +0x620[31:0] - MAC_ADDR[31:0]
> +0x630[15:0] - MAC_ADDR[47:32]
> +
> +In order to use the fuse API, we need to pass the bank and word values,
> which
> +are calculated as below:
> +
> +Fuse address for the lower MAC address: 0x620
> +Base address for the fuses: 0x400
> +
> +(0x620 - 0x400)/0x10 = 0x22 = 34 decimal
> +
> +As the fuses are arranged in banks of 8 words:
> +
> +34 / 8 = 4 and the remainder is 2, so in this case:
> +
> +bank = 4
> +word = 2
> +
> +And the U-boot command would be:
> +
> +=> fuse read 4 2
> +Reading bank 4:
> +
> +Word 0x00000002: 9f027772
> +
> +Doing the same for the upper MAC address:
> +
> +Fuse address for the upper MAC address: 0x630
> +Base address for the fuses: 0x400
> +
> +(0x630 - 0x400)/0x10 = 0x23 = 35 decimal
> +
> +As the fuses are arranged in banks of 8 words:
> +
> +35 / 8 = 4 and the remainder is 3, so in this case:
> +
> +bank = 4
> +word = 3
> +
> +And the U-boot command would be:
> +
> +=> fuse read 4 3
> +Reading bank 4:
> +
> +Word 0x00000003: 00000004
> +
> +,which matches the ethaddr value:
> +=> echo ${ethaddr}
> +00:04:9f:02:77:72
> --
> 1.8.1.2

Note that the documentation in this file is also completed for i.MX6 by
doc/README.mxc_ocotp and doc/README.imx6, as explained in each README. The
information that you add here regarding the location of the MAC fuses for i.MX6Q
is already present in doc/README.imx6.

Regarding the 'calculation' part, it is actually not needed since the values
obtained with these calculations are already given by the reference manual in
'46.5 OCOTP Memory Map/Register Definition'.

Examples could still be interesting though. What do you think?
 - Should the calculation part be removed and replaced with a reference to the
   RM ?46.5 be added?
 - Should this example be moved to doc/README.imx6, or kept in doc/README.fuse
   as a generic example for the fuse API?
 - Should an example be added to show how to read the whole MAC address with a
   single fuse command (i.e. 'fuse read 4 2 2')?

Best regards,
Beno?t

[U-Boot] [PATCH 1/2] doc: README.fuse: Add an example on how to use the fuse API on mx6q

[Stefano Babic]

Hi Beno?t, hi Fabio,

On 17/12/2013 22:18, Beno?t Th?baudeau wrote:
> Hi Fabio,
> 
> On Tuesday, December 17, 2013 9:03:40 PM, Fabio Estevam wrote:
>> From: Fabio Estevam <fabio.estevam@freescale.com>
>>
>> When using the fuse API in U-boot user must calculate the 'bank' and 'word'
>> values.
>>
>> Provide a real example on how to calculate such values for the mx6q.
>>
>> Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
>> ---
>>  doc/README.fuse | 57
>>  +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>>  1 file changed, 57 insertions(+)
>>
>> diff --git a/doc/README.fuse b/doc/README.fuse
>> index 1bc91c4..aca1e5e 100644
>> --- a/doc/README.fuse
>> +++ b/doc/README.fuse
>> @@ -65,3 +65,60 @@ Configuration:
>>  
>>     CONFIG_CMD_FUSE
>>        Define this to enable the fuse commands.
>> +
>> +Example:
>> +
>> +For reading the MAC address fuses on a MX6Q:
>> +
>> +- The MAC address are stored in two fuse addresses (the fuse addresses are
>> +described in the Fusemap Descriptions table from the mx6q Reference Manual):
>> +
>> +0x620[31:0] - MAC_ADDR[31:0]
>> +0x630[15:0] - MAC_ADDR[47:32]
>> +
>> +In order to use the fuse API, we need to pass the bank and word values,
>> which
>> +are calculated as below:
>> +
>> +Fuse address for the lower MAC address: 0x620
>> +Base address for the fuses: 0x400
>> +
>> +(0x620 - 0x400)/0x10 = 0x22 = 34 decimal
>> +
>> +As the fuses are arranged in banks of 8 words:
>> +
>> +34 / 8 = 4 and the remainder is 2, so in this case:
>> +
>> +bank = 4
>> +word = 2
>> +
>> +And the U-boot command would be:
>> +
>> +=> fuse read 4 2
>> +Reading bank 4:
>> +
>> +Word 0x00000002: 9f027772
>> +
>> +Doing the same for the upper MAC address:
>> +
>> +Fuse address for the upper MAC address: 0x630
>> +Base address for the fuses: 0x400
>> +
>> +(0x630 - 0x400)/0x10 = 0x23 = 35 decimal
>> +
>> +As the fuses are arranged in banks of 8 words:
>> +
>> +35 / 8 = 4 and the remainder is 3, so in this case:
>> +
>> +bank = 4
>> +word = 3
>> +
>> +And the U-boot command would be:
>> +
>> +=> fuse read 4 3
>> +Reading bank 4:
>> +
>> +Word 0x00000003: 00000004
>> +
>> +,which matches the ethaddr value:
>> +=> echo ${ethaddr}
>> +00:04:9f:02:77:72
>> --
>> 1.8.1.2
> 
> Note that the documentation in this file is also completed for i.MX6 by
> doc/README.mxc_ocotp and doc/README.imx6, as explained in each README. The
> information that you add here regarding the location of the MAC fuses for i.MX6Q
> is already present in doc/README.imx6.

This is true, but the current documentation is poor. I like that Fabio
adds a real example, providing a better understanding.

IMHO we should avoid to add a new file, if (as it is), this patch is
only for i.MX6. Putting it in README.imx6 seems the best solution.

> 
> Regarding the 'calculation' part, it is actually not needed since the values
> obtained with these calculations are already given by the reference manual in
> '46.5 OCOTP Memory Map/Register Definition'.

A reference is not bad, but of course documentation is changing. I was
working with manual 04/2013, and there is not an example - only "empty
example".
Anyway, most people is searching exactly how to store in SOC the MAC
address - not how to write another fuse. I think it is a good idea to
add the MAC's example, because it is what most people are looking for.

> 
> Examples could still be interesting though. What do you think?
>  - Should the calculation part be removed and replaced with a reference to the
>    RM ?46.5 be added?

I will add only a refererence, but I will let the example.

>  - Should this example be moved to doc/README.imx6,

+1, as the example is only for i.MX6.

Best regards,
Stefano Babic

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[U-Boot] [PATCH 1/2] doc: README.fuse: Add an example on how to use the fuse API on mx6q

[Fabio Estevam]

On Thu, Dec 19, 2013 at 7:49 AM, Stefano Babic <sbabic@denx.de> wrote:

>>  - Should this example be moved to doc/README.imx6,
>
> +1, as the example is only for i.MX6.

Sounds good. Just sent v2 as suggested.

Regards,

Fabio Estevam