? 2013?09?05? 12:25, Gupta, Pekon ??:

quoted

I would rather suggest to get these values from DT bindings specific to

could you show me what values should i set in the DT bindings?
The spi nor command? or the dummy? or something else?

Taking example of READ command for S25FL128S NOR flash devices..
S25FL128S supports following flavors of READ modes.
	4FAST_READ Read Fast (4-byte Address) 0C
	4READ Read (4-byte Address) 13
	4DOR Read Dual Out (4-byte Address) 3C
	4QOR Read Quad Out (4-byte Address) 6C
	4DIOR Dual I/O Read (4-byte Address) BC
	4QIOR Quad I/O Read (4-byte Address) EC
	4DDRFR Read DDR Fast (4-byte Address) 0E
	4DDRDIOR DDR Dual I/O Read (4-byte Address) BE
	4DDRQIOR DDR Quad I/O Read (4-byte Address) EE

But due to board constrains and your use-case, you would prefer only few
read modes. Those opcodes you can specify via following DT property.
"qspi, flash-read-command"

Same way you can have DT property for
"qspi, flash-write-command"
"qspi, flash-erase-command"
"qspi, flash-address-mode" = <4-byte/3-byte>
"qspi, flash-dummy-cycles" = <integer>

Example: How to select opcodes in DT ?
(step-1) eliminate opcode which cannot be used due to board constrains.
 your board connects only 2 data I/O between device and controller,  So you
 cannot use any of the QUAD  Read opcodes. Thus your choice is limited to
 DUAL or SINGLE modes only.

(step-2) select opcode based on use-case.
(a) To maximize your throughput you would mostly use DUAL read opcode
- fsl-qspi, flash-read-opcode = 0x3C  /* 4DOR Read Dual Out (4-byte Address) */
- fsl-qspi, flash-read-opcode = 0xBC  /* 4DIOR Dual I/O Read (4-byte Address) */
(b) But If you are using XIP then you would single out to:
- fsl-qspi, flash-read-opcode = 0xBC  /* 4DIOR Dual I/O Read (4-byte Address) */

Though I agree, end-user should be transparent of all these,
but this is better than asking them to submit patches for each new NOR device
..Any thoughts  ?

with regards, pekon