Skip to contentSkip to conversation

cfi_flash: Add prototypes of overridable functions

PATCH New Masahiro Yamada 3 participants 6 messages Jun 6, 2013 – Jul 30, 2013

lore
Share & tools
lore

Masahiro Yamada

author
#0 lore raw

PATCH 1/1 cfi_flash: Add prototypes of overridable functions

This commit adds some prototypes into include/mtd/cfi_flash.h. These functions are defined with a weak attribute in drivers/mtd/cfi_flash.c.
This means they can be overrided by board-specific ones if necessary.

When defining such functions under board/ directory or somewhere, cfi_flash.h should be included. This makes sure that board-specfic cfi functions are defined in a correct prototype.

Signed-off-by Masahiro Yamada <[email protected]>
---
 include/mtd/cfi_flash.h | 14 ++++++++++++++
 1 file changed, 14 insertions(+)
include/mtd/cfi_flash.h +14 -0
index b644b91..f97cf66 100644
@@ -184,5 +184,19 @@ extern int cfi_flash_num_flash_banks;
 
 void flash_write_cmd(flash_info_t * info, flash_sect_t sect,
 		     uint offset, u32 cmd);
+phys_addr_t cfi_flash_bank_addr(int i);
+unsigned long cfi_flash_bank_size(int i);
+void flash_cmd_reset(flash_info_t *info);
+
+#ifdef CONFIG_CFI_FLASH_USE_WEAK_ACCESSORS
+void flash_write8(u8 value, void *addr);
+void flash_write16(u16 value, void *addr);
+void flash_write32(u32 value, void *addr);
+void flash_write64(u64 value, void *addr);
+u8 flash_read8(void *addr);
+u16 flash_read16(void *addr);
+u32 flash_read32(void *addr);
+u64 flash_read64(void *addr);
+#endif
 
 #endif /* __CFI_FLASH_H__ */
Signature · 1 line
1.8.1.2
#1 lore raw

PATCH 1/1 cfi_flash: Add prototypes of overridable functions

Dear Masahiro Yamada,

Quoted 10 lines · In message <[email protected]> you…

This commit adds some prototypes into include/mtd/cfi_flash.h. These functions are defined with a weak attribute in drivers/mtd/cfi_flash.c.
This means they can be overrided by board-specific ones if necessary.

When defining such functions under board/ directory or somewhere, cfi_flash.h should be included. This makes sure that board-specfic cfi functions are defined in a correct prototype.

As is, this would just add dead code. Please resubmit this with any patch that would actually make use of this feature. this would also allow us to understand why this approch is needed at all.

Quoted 1 line

+#ifdef CONFIG_CFI_FLASH_USE_WEAK_ACCESSORS

When resubmitting, please keep in mind that new CONFIG_* options like this must be documented in the README.

Best regards,

Wolfgang Denk

Signature · 6 lines
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
Here is an Appalachian version of management's answer  to  those  who
are  concerned  with  the fate of the project: "Don't worry about the
mule. Just load the wagon."         - Mike Dennison's hillbilly uncle
author
#2 lore raw

PATCH 1/1 cfi_flash: Add prototypes of overridable functions

Hello, Wolfgang Denk.

Quoted 3 lines

As is, this would just add dead code. Please resubmit this with any patch that would actually make use of this feature. this would also allow us to understand why this approch is needed at all.

I'm not sure this is the best approach,
but these overrides are actually used by some boards.

I don't know very much about other companies, but I can explain how this override is being used for our boards in my company.
(Our board is not public. Only used inside Panasonic for LSI debug.
The board specific code is not posted yet.)
Our boards have very flexible memory slots.
We can use both SRAM and NOR flash for this slots and change base address easily.
So we probe NOR flash and configure base address at boot time, not compile time.
For this purpose, we override cfi_flash_bank_addr function with our own.

When I see board/lwmon5/lwmon5.c,
this feature seems to be used for similar purpose.

Quoted 4 lines
Quoted 1 line

+#ifdef CONFIG_CFI_FLASH_USE_WEAK_ACCESSORS

When resubmitting, please keep in mind that new CONFIG_* options like this must be documented in the README.

CONFIG_CFI_FLASH_USE_WEAK_ACCESSORS seems to be introduced by the following commit. I added Stefan in CC.

commit 45aa5a7f4d5bcb79927ddfc896c1d7c4326e235d

Author: Stefan Roese <[email protected]>
Date:   Mon Nov 17 14:45:22 2008 +0100

cfi_flash: Make all flash access functions weak

This patch defines all flash access functions as weak so that they can be overridden by board specific versions.

This will be used by the upcoming VCTH board support where the NOR FLASH unfortunately can't be accessed memory-mapped. Special accessor functions are needed here.

To enable this weak functions you need to define CONFIG_CFI_FLASH_USE_WEAK_ACCESSORS in your board config header. Otherwise the "old" default functions will be used resulting in smaller code.

Signed-off-by Stefan Roese <[email protected]>
Acked-by Haavard Skinnemoen <[email protected]>

Best Regards
Masahiro Yamada

Quoted 34 lines · On Thu, 06 Jun 2013 12:02:56 +0200 Wolfgang Denk <[email protected]> wrote:

Dear Masahiro Yamada,

Quoted 10 lines · In message <[email protected]> you…

This commit adds some prototypes into include/mtd/cfi_flash.h. These functions are defined with a weak attribute in drivers/mtd/cfi_flash.c.
This means they can be overrided by board-specific ones if necessary.

When defining such functions under board/ directory or somewhere, cfi_flash.h should be included. This makes sure that board-specfic cfi functions are defined in a correct prototype.

As is, this would just add dead code. Please resubmit this with any patch that would actually make use of this feature. this would also allow us to understand why this approch is needed at all.

Quoted 1 line

+#ifdef CONFIG_CFI_FLASH_USE_WEAK_ACCESSORS

When resubmitting, please keep in mind that new CONFIG_* options like this must be documented in the README.

Best regards,

Wolfgang Denk

Signature · 6 lines
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
Here is an Appalachian version of management's answer  to  those  who
are  concerned  with  the fate of the project: "Don't worry about the
mule. Just load the wagon."         - Mike Dennison's hillbilly uncle
Signature · 7 lines
????????? ????LSI????????
??????????
?????? ???????
????? <[email protected]>
?617-8520  ???????????1??
?? : 050-3783-5420
?? : 7-664-2813, ?????: 664-772
#3 lore raw

PATCH 1/1 cfi_flash: Add prototypes of overridable functions

In reply to Masahiro Yamada
Quoted 6 lines · Masahiro Yamada

This commit adds some prototypes into include/mtd/cfi_flash.h. These functions are defined with a weak attribute in drivers/mtd/cfi_flash.c.
This means they can be overrided by board-specific ones if necessary.

Quoted 6 lines

When defining such functions under board/ directory or somewhere, cfi_flash.h should be included. This makes sure that board-specfic cfi functions are defined in a correct prototype.

Signed-off-by Masahiro Yamada <[email protected]>

Is this patch still needed?

Thanks,
Stefan

author
#4 lore raw

PATCH 1/1 cfi_flash: Add prototypes of overridable functions

Hello Stefan

Quoted 1 line

Is this patch still needed?

Yes, I think so.

Best Regards
Masahiro Yamada

#5 lore raw

PATCH 1/1 cfi_flash: Add prototypes of overridable functions

Quoted 3 lines · Masahiro Yamada
Quoted 1 line

Is this patch still needed?

Yes, I think so.

Okay:

Applied to u-boot-cfi-flash.

Thanks,
Stefan