Re: [U-Boot] [RFC] mpc83xx: add config options to spd_sdram
Kim, York, ok - will give it a try tomorrow. hmm - having a look at the Makefile it looks like I need CONFIG_FSL_DDR2. This seems to pull in the new code ... without omitting the old one in arch/powerpc/cpu/mpc83xx/spd_sdram.c The Makefile further uses ctrl_regs.c ... which fails. having a look arch/powerpc/cpu/mpc8xxx/ddr/ctrl_regs.c gives : #ifdef CONFIG_MPC85xx #define _DDR_ADDR CONFIG_SYS_MPC85xx_DDR_ADDR #elif defined(CONFIG_MPC86xx) #define _DDR_ADDR CONFIG_SYS_MPC86xx_DDR_ADDR #else #error Undefined _DDR_ADDR #endif There's not a single sign of any 83xx within this code. Grepping through the board configs only show 85xx and 86xx based boards using it. Sorry, but I'm feeling like an idiot. Are you playing some game with me or am I simply unable to understand the code ? Please shed some light on this. Andre, I am sorry I totally ignored the subject with mpc83xx. I was thinking of mpc85xx. ok - no new code for 83xx then. You are right the old code is in spd_sdram.c and it is still in use for mpc83xx. Unless to adjust the code, there is no board specific file. Are you willing to accept some changes to spd_sdram.c or will I have another out-of-tree board ? What we need is : - more configurable settings like driver strength, cpo and odt values. - Reading SPD data from an arbitrary i2c eeprom. What's so bad about my proposal ? Please let me know so that I'm able to improve. Regards, André MATRIX VISION GmbH, Talstrasse 16, DE-71570 Oppenweiler Registergericht: Amtsgericht Stuttgart, HRB 271090 Geschaeftsfuehrer: Gerhard Thullner, Werner Armingeon, Uwe Furtner ___ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
Re: [U-Boot] [RFC] mpc83xx: add config options to spd_sdram
On Fri, 2011-04-08 at 09:41 +0200, Andre Schwarz wrote: I am sorry I totally ignored the subject with mpc83xx. I was thinking of mpc85xx. ok - no new code for 83xx then. You are right the old code is in spd_sdram.c and it is still in use for mpc83xx. Unless to adjust the code, there is no board specific file. Are you willing to accept some changes to spd_sdram.c or will I have another out-of-tree board ? What we need is : - more configurable settings like driver strength, cpo and odt values. - Reading SPD data from an arbitrary i2c eeprom. What's so bad about my proposal ? Please let me know so that I'm able to improve. I welcome the change to use the new code since the feature you asked is already there. York ___ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
Re: [U-Boot] [RFC] mpc83xx: add config options to spd_sdram
York, On Fri, 2011-04-08 at 09:41 +0200, Andre Schwarz wrote: I am sorry I totally ignored the subject with mpc83xx. I was thinking of mpc85xx. ok - no new code for 83xx then. You are right the old code is in spd_sdram.c and it is still in use for mpc83xx. Unless to adjust the code, there is no board specific file. Are you willing to accept some changes to spd_sdram.c or will I have another out-of-tree board ? What we need is : - more configurable settings like driver strength, cpo and odt values. - Reading SPD data from an arbitrary i2c eeprom. What's so bad about my proposal ? Please let me know so that I'm able to improve. I welcome the change to use the new code since the feature you asked is already there. sorry, but I'm not sure if I understand this correctly. What I need is some minor non-intrusive changes to 83xx-specific file spd_sdram.c because it is the most straightforward solution with *no* impact on code size or other existing boards. So: The feature I ask for is *not* already there. What I definitely won't do is use the new fsl ddr code in mpc8xxx/ddr because it completely lacks 83xx support. So: The feature I ask for is there but my CPU family is not supported. IMHO the new code is total overkill for 83xx. Cheers, André MATRIX VISION GmbH, Talstrasse 16, DE-71570 Oppenweiler Registergericht: Amtsgericht Stuttgart, HRB 271090 Geschaeftsfuehrer: Gerhard Thullner, Werner Armingeon, Uwe Furtner ___ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
Re: [U-Boot] [RFC] mpc83xx: add config options to spd_sdram
On Fri, 2011-04-08 at 18:29 +0200, Andre Schwarz wrote: York, On Fri, 2011-04-08 at 09:41 +0200, Andre Schwarz wrote: I am sorry I totally ignored the subject with mpc83xx. I was thinking of mpc85xx. ok - no new code for 83xx then. You are right the old code is in spd_sdram.c and it is still in use for mpc83xx. Unless to adjust the code, there is no board specific file. Are you willing to accept some changes to spd_sdram.c or will I have another out-of-tree board ? What we need is : - more configurable settings like driver strength, cpo and odt values. - Reading SPD data from an arbitrary i2c eeprom. What's so bad about my proposal ? Please let me know so that I'm able to improve. I welcome the change to use the new code since the feature you asked is already there. sorry, but I'm not sure if I understand this correctly. What I need is some minor non-intrusive changes to 83xx-specific file spd_sdram.c because it is the most straightforward solution with *no* impact on code size or other existing boards. So: The feature I ask for is *not* already there. What I definitely won't do is use the new fsl ddr code in mpc8xxx/ddr because it completely lacks 83xx support. So: The feature I ask for is there but my CPU family is not supported. IMHO the new code is total overkill for 83xx. It would be easier to maintain one set of code. But if the change you need is relatively small to the old code and doesn't have negative impact on other boards, go ahead to post the patch. York ___ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
Re: [U-Boot] [RFC] mpc83xx: add config options to spd_sdram
On 04/08/2011 06:36 PM, York Sun wrote: On Fri, 2011-04-08 at 18:29 +0200, Andre Schwarz wrote: York, On Fri, 2011-04-08 at 09:41 +0200, Andre Schwarz wrote: I am sorry I totally ignored the subject with mpc83xx. I was thinking of mpc85xx. ok - no new code for 83xx then. You are right the old code is in spd_sdram.c and it is still in use for mpc83xx. Unless to adjust the code, there is no board specific file. Are you willing to accept some changes to spd_sdram.c or will I have another out-of-tree board ? What we need is : - more configurable settings like driver strength, cpo and odt values. - Reading SPD data from an arbitrary i2c eeprom. What's so bad about my proposal ? Please let me know so that I'm able to improve. I welcome the change to use the new code since the feature you asked is already there. sorry, but I'm not sure if I understand this correctly. What I need is some minor non-intrusive changes to 83xx-specific file spd_sdram.c because it is the most straightforward solution with *no* impact on code size or other existing boards. So: The feature I ask for is *not* already there. What I definitely won't do is use the new fsl ddr code in mpc8xxx/ddr because it completely lacks 83xx support. So: The feature I ask for is there but my CPU family is not supported. IMHO the new code is total overkill for 83xx. It would be easier to maintain one set of code. But if the change you need is relatively small to the old code and doesn't have negative impact on other boards, go ahead to post the patch. yes - that's what I've been asking for. So far Kim's NAK is still valid - let's see what his favorite solution will look like. Thank you for sharing your thoughts. Regards, André MATRIX VISION GmbH, Talstrasse 16, DE-71570 Oppenweiler Registergericht: Amtsgericht Stuttgart, HRB 271090 Geschaeftsfuehrer: Gerhard Thullner, Werner Armingeon, Uwe Furtner ___ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
Re: [U-Boot] [RFC] mpc83xx: add config options to spd_sdram
York, Schwarz,Andre andre.schw...@matrix-vision.de hat am 6. April 2011 um 20:42 geschrieben: York, ok - will give it a try tomorrow. hmm - having a look at the Makefile it looks like I need CONFIG_FSL_DDR2. This seems to pull in the new code ... without omitting the old one in arch/powerpc/cpu/mpc83xx/spd_sdram.c The Makefile further uses ctrl_regs.c ... which fails. having a look arch/powerpc/cpu/mpc8xxx/ddr/ctrl_regs.c gives : #ifdef CONFIG_MPC85xx #define _DDR_ADDR CONFIG_SYS_MPC85xx_DDR_ADDR #elif defined(CONFIG_MPC86xx) #define _DDR_ADDR CONFIG_SYS_MPC86xx_DDR_ADDR #else #error Undefined _DDR_ADDR #endif There's not a single sign of any 83xx within this code. Grepping through the board configs only show 85xx and 86xx based boards using it. Sorry, but I'm feeling like an idiot. Are you playing some game with me or am I simply unable to understand the code ? Please shed some light on this. Regards, André York Sun york...@freescale.com hat am 6. April 2011 um 18:37 geschrieben: On Wed, 2011-04-06 at 10:18 +0200, Andre Schwarz wrote: Kim, York, I have made some mods to spd_sdram.c for various reason: 1. use SPD setup also for soldered RAM. This allows DDR mounting options without U-Boot change because SPD data is written during in-circuit/boundary-scan testing. not sure I understand this - board with soldered RAM can't physically get the SPD data from RAM, yet SPD data were somehow acquired and written into some ROM, so spd_sdram() is still needed to parse program the controller without requiring a new u-boot binary? SPD data is nothing more than an I2C-EEPROM soldered on each memory module containing the physical details of the memory devices. Since I already have an I2C-EEPROM on the board I can use it for SPD data, i.e. the board's memory is configured using normal detection routines. During production (exactly: board testing) the EEPROM will be programmed with an SPD table matching the soldered memory devices. This gives some flexibility regarding size and speed grades ... some devices have pretty short life-cycles. That's right. If you have the SPD in I2C-EEPROM, you have a real SPD as far as software concerns. Just provide the I2C address. 3. for optimized signal integrity and power consumption we need more influence on the on-die termination. Although the assumed default values are working they are far from ideal. board specific things like this are perfectly acceptable, of course. ok. however, it should not be being done by glittering old-83xx/spd_sdram with an extra #ifdef for every new parameter ok - what about this : #if !defined(CONFIG_SYS_DDR_MODE_ODT_VALUE) #define CONFIG_SYS_DDR_MODE_ODT_VALUE 0x40 #endif mode_odt_enable = CONFIG_SYS_DDR_MODE_ODT_VALUE; I really can't think of this change being a problem for anybody. I would suggest to put it in fsl_ddr_board_options() in ddr.c under the board directory. There you can override any options, including popts-cs_local_opts[i].odt_rd_cfg popts-cs_local_opts[i].odt_wr_cfg popts-cpo_override York -- Gruß, André Schwarz MATRIX VISION GmbH, Talstrasse 16, DE-71570 Oppenweiler Registergericht: Amtsgericht Stuttgart, HRB 271090 Geschaeftsfuehrer: Gerhard Thullner, Werner Armingeon, Uwe Furtner ___ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
Re: [U-Boot] [RFC] mpc83xx: add config options to spd_sdram
On Thu, 2011-04-07 at 22:42 +0200, Schwarz,Andre wrote: York, Schwarz,Andre andre.schw...@matrix-vision.de hat am 6. April 2011 um 20:42 geschrieben: York, ok - will give it a try tomorrow. hmm - having a look at the Makefile it looks like I need CONFIG_FSL_DDR2. This seems to pull in the new code ... without omitting the old one in arch/powerpc/cpu/mpc83xx/spd_sdram.c The Makefile further uses ctrl_regs.c ... which fails. having a look arch/powerpc/cpu/mpc8xxx/ddr/ctrl_regs.c gives : #ifdef CONFIG_MPC85xx #define _DDR_ADDR CONFIG_SYS_MPC85xx_DDR_ADDR #elif defined(CONFIG_MPC86xx) #define _DDR_ADDR CONFIG_SYS_MPC86xx_DDR_ADDR #else #error Undefined _DDR_ADDR #endif There's not a single sign of any 83xx within this code. Grepping through the board configs only show 85xx and 86xx based boards using it. Sorry, but I'm feeling like an idiot. Are you playing some game with me or am I simply unable to understand the code ? Please shed some light on this. Andre, I am sorry I totally ignored the subject with mpc83xx. I was thinking of mpc85xx. You are right the old code is in spd_sdram.c and it is still in use for mpc83xx. Unless to adjust the code, there is no board specific file. York ___ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
Re: [U-Boot] [RFC] mpc83xx: add config options to spd_sdram
Kim, York,
I have made some mods to spd_sdram.c for various reason:
1.
use SPD setup also for soldered RAM.
This allows DDR mounting options without U-Boot change because SPD data
is written during in-circuit/boundary-scan testing.
not sure I understand this - board with soldered RAM can't physically
get the SPD data from RAM, yet SPD data were somehow acquired and
written into some ROM, so spd_sdram() is still needed to parse
program the controller without requiring a new u-boot binary?
SPD data is nothing more than an I2C-EEPROM soldered on each memory module
containing the physical details of the memory devices.
Since I already have an I2C-EEPROM on the board I can use it for SPD
data, i.e.
the board's memory is configured using normal detection routines.
During production (exactly: board testing) the EEPROM will be programmed
with an SPD
table matching the soldered memory devices. This gives some flexibility
regarding size and
speed grades ... some devices have pretty short life-cycles.
this isn't included in the below diff, right?
yes it is - all I need is to provide the EEPROM's I2C adress and the
offset of the SPD table.
2.
read SPD data also from extended adressing EEPROMS used for e.g. HRCW
storage.
Due to HRCW being being located at offset 0 we need an SPD data offset.
and this is the SPD_EEPROM_OFFSET stuff below? hmm..
yes - since the start of EEPROM memory is already occupied by HRCW.
so both 1 2 are coagulated in my mind - ideally, this would be
implemented with the new ddr code in
arch/powerpc/cpu/mpc8xxx/ddr/main.c - see fsl_ddr_compute(), which has
a GET_SPD step that would need to be either skipped (i.e, start_step =
COMPUTE_DIMM_PARMS), or changed to be able to be overridden, or,
ideally, all DIMM computations would be precomputed and stored in ROM
and a direct start_step to e.g., STEP_ASSIGN_ADDRESSES were made.
Currently the spd_sdram is doing *exactly* what I need.
From my point of view there's no need to move to new code.
3.
for optimized signal integrity and power consumption we need more
influence on
the on-die termination. Although the assumed default values are working they
are far from ideal.
board specific things like this are perfectly acceptable, of course.
ok.
however, it should not be being done by glittering old-83xx/spd_sdram
with an extra #ifdef for every new parameter
ok - what about this :
#if !defined(CONFIG_SYS_DDR_MODE_ODT_VALUE)
#define CONFIG_SYS_DDR_MODE_ODT_VALUE 0x40
#endif
mode_odt_enable = CONFIG_SYS_DDR_MODE_ODT_VALUE;
I really can't think of this change being a problem for anybody.
that is needed, especially
when this is all fixed in the new ddr code. So, in preparation for
83xx to eventually migrate to the new ddr code,
understood - but the effort needed to dig through the new code and
get it up and running is hardly justified by the sole need to set a
proper ODT value.
I did not even come to speak of an increased memory footprint.
I'll have to provide a patch these days for a 8343 based board removing
features
due binary size constantly growing ...
I'd like this to be
done in such a way so as to start to conform to the new code by at least
defining ODT, etc. parameters in a board-specific
ddr.c:fsl_ddr_board_options(). See board/freescale/{p1022ds,*}/ddr.c
for example.
ok - understood.
I'm willing to do it but not all at once.
4.
CPO values depend on internal bond wire length which has significantly
high variance on MPC837x, i.e. this value also should be board specific.
again, to be defined as popts-cpo_override in the board-specific
ddr.c:fsl_ddr_board_options().
ok.
I have taken care not to increase code size and not to break existing
boards.
Any comments from your side ?
Is this something you might ACK ?
not as-is - see above, and let me know what you think.
I fully understand that you want the new code to be used and I'll use it
asap.
But right now the spd_sdram is working fine and I need this flexibility
using
the local EEPROM.
IMHO this patch is not breaking anything and completely transparent.
Not a single byte of code increase either
Regards,
André
MATRIX VISION GmbH, Talstrasse 16, DE-71570 Oppenweiler
Registergericht: Amtsgericht Stuttgart, HRB 271090
Geschaeftsfuehrer: Gerhard Thullner, Werner Armingeon, Uwe Furtner
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Re: [U-Boot] [RFC] mpc83xx: add config options to spd_sdram
York,
I have made some mods to spd_sdram.c for various reason:
1.
use SPD setup also for soldered RAM.
This allows DDR mounting options without U-Boot change because SPD data
is written during in-circuit/boundary-scan testing.
not sure I understand this - board with soldered RAM can't physically
get the SPD data from RAM, yet SPD data were somehow acquired and
written into some ROM, so spd_sdram() is still needed to parse
program the controller without requiring a new u-boot binary?
this isn't included in the below diff, right?
Actually I have code for this already, pending for more broader testing.
I use raw timing data from datasheet of DDR chips. We have an internal
discussion to recommend using EEPROM to mimic SPD structure.
sorry - I don't understand this.
Why do you want to create something new if there's a standard
like SPD layout ? It is working perfectly fine and the data can be
obtained from the manufacturer without further modifications.
2.
read SPD data also from extended adressing EEPROMS used for e.g. HRCW
storage.
Due to HRCW being being located at offset 0 we need an SPD data offset.
and this is the SPD_EEPROM_OFFSET stuff below? hmm..
so both 1 2 are coagulated in my mind - ideally, this would be
implemented with the new ddr code in
arch/powerpc/cpu/mpc8xxx/ddr/main.c - see fsl_ddr_compute(), which has
a GET_SPD step that would need to be either skipped (i.e, start_step =
COMPUTE_DIMM_PARMS), or changed to be able to be overridden, or,
ideally, all DIMM computations would be precomputed and stored in ROM
and a direct start_step to e.g., STEP_ASSIGN_ADDRESSES were made.
I don't 100% agree with the idea to put SPD-like data in HRCW.
The SPD data has nothing to do with HRCW - it's just stored in the same
PROM.
How can you be sure the data matches DDR?
Because the SPD data gets programmed during production.
We can use any SPD table *exactly* matching the soldered parts.
It would be equivalent to using fixed raw timing data, wouldn't it?
no - it isn't.
I want the *same* U-Boot binary running on *different* memory
configurations, i.e.
*no* fixed timing at all.
3.
for optimized signal integrity and power consumption we need more
influence on
the on-die termination. Although the assumed default values are working they
are far from ideal.
board specific things like this are perfectly acceptable, of course.
however, it should not be being done by glittering old-83xx/spd_sdram
with an extra #ifdef for every new parameter that is needed, especially
when this is all fixed in the new ddr code. So, in preparation for
83xx to eventually migrate to the new ddr code, I'd like this to be
done in such a way so as to start to conform to the new code by at least
defining ODT, etc. parameters in a board-specific
ddr.c:fsl_ddr_board_options(). See board/freescale/{p1022ds,*}/ddr.c
for example.
The ODT table is implemented in options.c and it can be override by
board functions. Look for the last function in options.c and ddr.c
under the board folder.
To me it is a fundamental design error to rely on environment data to set
up the hardware correctly. Especially something that critical as memory
configuration.
Do you expect U-Boot to work with a corrupted environment, i.e. hwconfig
value unavailable ?
Of course this might never happen on a reference design board - but
that's not real life.
4.
CPO values depend on internal bond wire length which has significantly
high variance on MPC837x, i.e. this value also should be board specific.
again, to be defined as popts-cpo_override in the board-specific
ddr.c:fsl_ddr_board_options().
I recommend to use auto calibration. If for some reason, you want to
override, it belongs to board specific file, same as the above.
no - auto calibration is far from ideal regarding emc and power consumption.
Regards,
André
MATRIX VISION GmbH, Talstrasse 16, DE-71570 Oppenweiler
Registergericht: Amtsgericht Stuttgart, HRB 271090
Geschaeftsfuehrer: Gerhard Thullner, Werner Armingeon, Uwe Furtner
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Re: [U-Boot] [RFC] mpc83xx: add config options to spd_sdram
On Wed, 2011-04-06 at 10:42 +0200, Andre Schwarz wrote:
York,
I have made some mods to spd_sdram.c for various reason:
1.
use SPD setup also for soldered RAM.
This allows DDR mounting options without U-Boot change because SPD data
is written during in-circuit/boundary-scan testing.
not sure I understand this - board with soldered RAM can't physically
get the SPD data from RAM, yet SPD data were somehow acquired and
written into some ROM, so spd_sdram() is still needed to parse
program the controller without requiring a new u-boot binary?
this isn't included in the below diff, right?
Actually I have code for this already, pending for more broader testing.
I use raw timing data from datasheet of DDR chips. We have an internal
discussion to recommend using EEPROM to mimic SPD structure.
sorry - I don't understand this.
Why do you want to create something new if there's a standard
like SPD layout ? It is working perfectly fine and the data can be
obtained from the manufacturer without further modifications.
I am not creating anything new. For some platforms with soldered DDR
components, there is no SPD on board. We need to either create the
SPD-like structure, or use the raw timing data from datasheet.
2.
read SPD data also from extended adressing EEPROMS used for e.g. HRCW
storage.
Due to HRCW being being located at offset 0 we need an SPD data offset.
and this is the SPD_EEPROM_OFFSET stuff below? hmm..
so both 1 2 are coagulated in my mind - ideally, this would be
implemented with the new ddr code in
arch/powerpc/cpu/mpc8xxx/ddr/main.c - see fsl_ddr_compute(), which has
a GET_SPD step that would need to be either skipped (i.e, start_step =
COMPUTE_DIMM_PARMS), or changed to be able to be overridden, or,
ideally, all DIMM computations would be precomputed and stored in ROM
and a direct start_step to e.g., STEP_ASSIGN_ADDRESSES were made.
I don't 100% agree with the idea to put SPD-like data in HRCW.
The SPD data has nothing to do with HRCW - it's just stored in the same
PROM.
How can you be sure the data matches DDR?
Because the SPD data gets programmed during production.
We can use any SPD table *exactly* matching the soldered parts.
Agreed as far as the SPD data is not easily erased by mistake.
It would be equivalent to using fixed raw timing data, wouldn't it?
no - it isn't.
I want the *same* U-Boot binary running on *different* memory
configurations, i.e.
*no* fixed timing at all.
As far as the SPD data is persistent.
3.
for optimized signal integrity and power consumption we need more
influence on
the on-die termination. Although the assumed default values are working
they
are far from ideal.
board specific things like this are perfectly acceptable, of course.
however, it should not be being done by glittering old-83xx/spd_sdram
with an extra #ifdef for every new parameter that is needed, especially
when this is all fixed in the new ddr code. So, in preparation for
83xx to eventually migrate to the new ddr code, I'd like this to be
done in such a way so as to start to conform to the new code by at least
defining ODT, etc. parameters in a board-specific
ddr.c:fsl_ddr_board_options(). See board/freescale/{p1022ds,*}/ddr.c
for example.
The ODT table is implemented in options.c and it can be override by
board functions. Look for the last function in options.c and ddr.c
under the board folder.
To me it is a fundamental design error to rely on environment data to set
up the hardware correctly. Especially something that critical as memory
configuration.
Do you expect U-Boot to work with a corrupted environment, i.e. hwconfig
value unavailable ?
Of course this might never happen on a reference design board - but
that's not real life.
It is not in environmental variable.
4.
CPO values depend on internal bond wire length which has significantly
high variance on MPC837x, i.e. this value also should be board specific.
again, to be defined as popts-cpo_override in the board-specific
ddr.c:fsl_ddr_board_options().
I recommend to use auto calibration. If for some reason, you want to
override, it belongs to board specific file, same as the above.
no - auto calibration is far from ideal regarding emc and power consumption.
Then just use whatever parameter fits. Again, it is in the board ddr
file.
York
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Re: [U-Boot] [RFC] mpc83xx: add config options to spd_sdram
On Wed, 2011-04-06 at 10:18 +0200, Andre Schwarz wrote: Kim, York, I have made some mods to spd_sdram.c for various reason: 1. use SPD setup also for soldered RAM. This allows DDR mounting options without U-Boot change because SPD data is written during in-circuit/boundary-scan testing. not sure I understand this - board with soldered RAM can't physically get the SPD data from RAM, yet SPD data were somehow acquired and written into some ROM, so spd_sdram() is still needed to parse program the controller without requiring a new u-boot binary? SPD data is nothing more than an I2C-EEPROM soldered on each memory module containing the physical details of the memory devices. Since I already have an I2C-EEPROM on the board I can use it for SPD data, i.e. the board's memory is configured using normal detection routines. During production (exactly: board testing) the EEPROM will be programmed with an SPD table matching the soldered memory devices. This gives some flexibility regarding size and speed grades ... some devices have pretty short life-cycles. That's right. If you have the SPD in I2C-EEPROM, you have a real SPD as far as software concerns. Just provide the I2C address. 3. for optimized signal integrity and power consumption we need more influence on the on-die termination. Although the assumed default values are working they are far from ideal. board specific things like this are perfectly acceptable, of course. ok. however, it should not be being done by glittering old-83xx/spd_sdram with an extra #ifdef for every new parameter ok - what about this : #if !defined(CONFIG_SYS_DDR_MODE_ODT_VALUE) #define CONFIG_SYS_DDR_MODE_ODT_VALUE 0x40 #endif mode_odt_enable = CONFIG_SYS_DDR_MODE_ODT_VALUE; I really can't think of this change being a problem for anybody. I would suggest to put it in fsl_ddr_board_options() in ddr.c under the board directory. There you can override any options, including popts-cs_local_opts[i].odt_rd_cfg popts-cs_local_opts[i].odt_wr_cfg popts-cpo_override York ___ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
Re: [U-Boot] [RFC] mpc83xx: add config options to spd_sdram
York, ok - will give it a try tomorrow. Cheers, André York Sun york...@freescale.com hat am 6. April 2011 um 18:37 geschrieben: On Wed, 2011-04-06 at 10:18 +0200, Andre Schwarz wrote: Kim, York, I have made some mods to spd_sdram.c for various reason: 1. use SPD setup also for soldered RAM. This allows DDR mounting options without U-Boot change because SPD data is written during in-circuit/boundary-scan testing. not sure I understand this - board with soldered RAM can't physically get the SPD data from RAM, yet SPD data were somehow acquired and written into some ROM, so spd_sdram() is still needed to parse program the controller without requiring a new u-boot binary? SPD data is nothing more than an I2C-EEPROM soldered on each memory module containing the physical details of the memory devices. Since I already have an I2C-EEPROM on the board I can use it for SPD data, i.e. the board's memory is configured using normal detection routines. During production (exactly: board testing) the EEPROM will be programmed with an SPD table matching the soldered memory devices. This gives some flexibility regarding size and speed grades ... some devices have pretty short life-cycles. That's right. If you have the SPD in I2C-EEPROM, you have a real SPD as far as software concerns. Just provide the I2C address. 3. for optimized signal integrity and power consumption we need more influence on the on-die termination. Although the assumed default values are working they are far from ideal. board specific things like this are perfectly acceptable, of course. ok. however, it should not be being done by glittering old-83xx/spd_sdram with an extra #ifdef for every new parameter ok - what about this : #if !defined(CONFIG_SYS_DDR_MODE_ODT_VALUE) #define CONFIG_SYS_DDR_MODE_ODT_VALUE 0x40 #endif mode_odt_enable = CONFIG_SYS_DDR_MODE_ODT_VALUE; I really can't think of this change being a problem for anybody. I would suggest to put it in fsl_ddr_board_options() in ddr.c under the board directory. There you can override any options, including popts-cs_local_opts[i].odt_rd_cfg popts-cs_local_opts[i].odt_wr_cfg popts-cpo_override York -- Gruß, André Schwarz MATRIX VISION GmbH, Talstrasse 16, DE-71570 Oppenweiler Registergericht: Amtsgericht Stuttgart, HRB 271090 Geschaeftsfuehrer: Gerhard Thullner, Werner Armingeon, Uwe Furtner ___ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
Re: [U-Boot] [RFC] mpc83xx: add config options to spd_sdram
On Tue, 5 Apr 2011 11:49:49 +0200
Andre Schwarz andre.schw...@matrix-vision.de wrote:
Cc'ing York Sun, who knows a little more about this stuff than I do.
I have made some mods to spd_sdram.c for various reason:
1.
use SPD setup also for soldered RAM.
This allows DDR mounting options without U-Boot change because SPD data
is written during in-circuit/boundary-scan testing.
not sure I understand this - board with soldered RAM can't physically
get the SPD data from RAM, yet SPD data were somehow acquired and
written into some ROM, so spd_sdram() is still needed to parse
program the controller without requiring a new u-boot binary?
this isn't included in the below diff, right?
2.
read SPD data also from extended adressing EEPROMS used for e.g. HRCW
storage.
Due to HRCW being being located at offset 0 we need an SPD data offset.
and this is the SPD_EEPROM_OFFSET stuff below? hmm..
so both 1 2 are coagulated in my mind - ideally, this would be
implemented with the new ddr code in
arch/powerpc/cpu/mpc8xxx/ddr/main.c - see fsl_ddr_compute(), which has
a GET_SPD step that would need to be either skipped (i.e, start_step =
COMPUTE_DIMM_PARMS), or changed to be able to be overridden, or,
ideally, all DIMM computations would be precomputed and stored in ROM
and a direct start_step to e.g., STEP_ASSIGN_ADDRESSES were made.
3.
for optimized signal integrity and power consumption we need more
influence on
the on-die termination. Although the assumed default values are working they
are far from ideal.
board specific things like this are perfectly acceptable, of course.
however, it should not be being done by glittering old-83xx/spd_sdram
with an extra #ifdef for every new parameter that is needed, especially
when this is all fixed in the new ddr code. So, in preparation for
83xx to eventually migrate to the new ddr code, I'd like this to be
done in such a way so as to start to conform to the new code by at least
defining ODT, etc. parameters in a board-specific
ddr.c:fsl_ddr_board_options(). See board/freescale/{p1022ds,*}/ddr.c
for example.
4.
CPO values depend on internal bond wire length which has significantly
high variance on MPC837x, i.e. this value also should be board specific.
again, to be defined as popts-cpo_override in the board-specific
ddr.c:fsl_ddr_board_options().
I have taken care not to increase code size and not to break existing
boards.
Any comments from your side ?
Is this something you might ACK ?
not as-is - see above, and let me know what you think.
Kim
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Re: [U-Boot] [RFC] mpc83xx: add config options to spd_sdram
On Tue, 2011-04-05 at 16:52 -0500, Kim Phillips wrote:
On Tue, 5 Apr 2011 11:49:49 +0200
Andre Schwarz andre.schw...@matrix-vision.de wrote:
Cc'ing York Sun, who knows a little more about this stuff than I do.
I have made some mods to spd_sdram.c for various reason:
1.
use SPD setup also for soldered RAM.
This allows DDR mounting options without U-Boot change because SPD data
is written during in-circuit/boundary-scan testing.
not sure I understand this - board with soldered RAM can't physically
get the SPD data from RAM, yet SPD data were somehow acquired and
written into some ROM, so spd_sdram() is still needed to parse
program the controller without requiring a new u-boot binary?
this isn't included in the below diff, right?
Actually I have code for this already, pending for more broader testing.
I use raw timing data from datasheet of DDR chips. We have an internal
discussion to recommend using EEPROM to mimic SPD structure.
2.
read SPD data also from extended adressing EEPROMS used for e.g. HRCW
storage.
Due to HRCW being being located at offset 0 we need an SPD data offset.
and this is the SPD_EEPROM_OFFSET stuff below? hmm..
so both 1 2 are coagulated in my mind - ideally, this would be
implemented with the new ddr code in
arch/powerpc/cpu/mpc8xxx/ddr/main.c - see fsl_ddr_compute(), which has
a GET_SPD step that would need to be either skipped (i.e, start_step =
COMPUTE_DIMM_PARMS), or changed to be able to be overridden, or,
ideally, all DIMM computations would be precomputed and stored in ROM
and a direct start_step to e.g., STEP_ASSIGN_ADDRESSES were made.
I don't 100% agree with the idea to put SPD-like data in HRCW. How can
you be sure the data matches DDR? It would be equivalent to using fixed
raw timing data, wouldn't it?
3.
for optimized signal integrity and power consumption we need more
influence on
the on-die termination. Although the assumed default values are working they
are far from ideal.
board specific things like this are perfectly acceptable, of course.
however, it should not be being done by glittering old-83xx/spd_sdram
with an extra #ifdef for every new parameter that is needed, especially
when this is all fixed in the new ddr code. So, in preparation for
83xx to eventually migrate to the new ddr code, I'd like this to be
done in such a way so as to start to conform to the new code by at least
defining ODT, etc. parameters in a board-specific
ddr.c:fsl_ddr_board_options(). See board/freescale/{p1022ds,*}/ddr.c
for example.
The ODT table is implemented in options.c and it can be override by
board functions. Look for the last function in options.c and ddr.c
under the board folder.
4.
CPO values depend on internal bond wire length which has significantly
high variance on MPC837x, i.e. this value also should be board specific.
again, to be defined as popts-cpo_override in the board-specific
ddr.c:fsl_ddr_board_options().
I recommend to use auto calibration. If for some reason, you want to
override, it belongs to board specific file, same as the above.
York
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