Am 06.12.2018 um 18:39 schrieb Vignesh R:
On 06/12/18 10:06 PM, Simon Goldschmidt wrote:
Am 06.12.2018 um 14:54 schrieb Simon Goldschmidt:
On Thu, Dec 6, 2018 at 2:45 PM Vignesh R <[email protected]> wrote:
Hi Simon,
On 06/12/18 2:15 AM, Simon Goldschmidt wrote:
Am 05.12.2018 um 07:55 schrieb Simon Goldschmidt:
On Wed, Dec 5, 2018 at 7:51 AM Vignesh R <[email protected]> wrote:
[...]
I did some compilation tests first and I'm happy to say that with the
SPL_SPI_FLASH_TINY option enabled, my SPL is about 1900 byte smaller
than before :-)
However, my socfpga socrates board does not boot. I'll have to
investigate why. I just applied this series and compiled for
socfpga_socrates_defconfig. Is there anything else I should have changed
to make it work?
Oops, that's unfortunate.
Just to be sure, does SPL fail to come up or SPL fails to load U-Boot
from flash? Is this with SPL_SPI_FLASH_TINY enabled?
I tried both TINY and standard. Both are failing to load U-Boot (I get
the standard error message that loading from SPI flash failed).
Could you enable debug prints at the end of spi_mem_exec_op() in
drivers/spi/spi-mem.c to see what commands are sent and their responses?
OK, I'll do that.
I have TI EVM with Cadence QSPI(like SoCFPGA) but with a Spansion flash
and that seems to work fine with both full and tiny stack.
OK, so I enabled some debugging and the first issue is that U-Boot has
SNOR_MFR_MICRON and SNOR_MFR_ST while Linux only has SNOR_MFR_MICRON but
defines it to CFI_MFR_ST (0x20, U-Boot ends up with 0x2c). While this
might be correct, it leads to my n25q256a not being handled as
"micron-like" and the code falls through to using Spansion-like opcode
(0x17) that my chip does not understand.
Oops, sorry, the micron chip I had has CFI MFR id of 0x2c, so I
overlooked this. I have updated this now.
However, after changing this (and using opcode 0xb7 to bring the chip
into 4 byte mode, including 0x06 for write-enable), it still does not
work as it uses the 'READ' opcode 0x03 instead of the 'FAST READ' opcode
0x0b that U-Boot used until now. The problem here might be that 'READ'
cannot do Quad-SPI (4-4-4) and I'm not sure the Cadence driver can
handle Extended-SPI (1-1-1) that the 'READ' command is limited to...
I had accidentally dropped Fast Read from SPI NOR layer and have sync'd
it up now. I see that in socfpga dts, flash does not contain:
spi-rx-bus-width = <4>;
We can add that if it helps. I'll try to update the upstream Linux dts
anyway to add "jeded,spi-nor" compatible once Neil's series is
applied.
Therefore SPI NOR layer falls back to READ (even though its a QSPI
flash). But nevertheless with updated branch[1] you should see falling
back to FAST READ with Cadence QSPI on your board (and 1-1-4, if rx bus
width is 4).
Using SFDP would probably help, but that doesn't compile (as I wrote in
the other thread).
Sorry for that. I have fixed that up and tested SFDP parsing logic with
a Spansion flash. Note that Cadence QSPI wont support SFDP parsing as
driver enables Quad mode for all reads and SFDP is only 1-1-1.
Oh, I haven't really looked into that yet. That's sad.
Yes, thats one of the motivation for this series. I wanted to use same driver
to support Cadence Octal SPI IP but this simply wasn't possible due disconnect
b/w SF and SPI layer.
I plan to fix Cadence QSPI by moving to spi-mem layer once SF layer is in place
On the other hand, enabling SFDP will increase the text/rodata size for
SPL. We might need to remove the non-SFDP and write code as a counter
measure to prevent increasing code size.
That's not an option as Flash devices (even though have same JEDEC ID)
manufactured before JESD216 std dont have SFDP populated. So, we will
need to have both non-SFDP and SFDP support with option to disable SFDP
(for size and boot time optimizations).
Well, my idea was if you'd know that all the flash chips on your board
supported it, you'd be safe. It would only be a Kconfig option to
reduce binary size (get rid of the flash IDs table).
But if SFDP doesn't work for QSPI anyway, that's not the best idea, I guess...
Yeah, current U-Boot SPI layer does not allow SPI Flash layer to communicate
bus width to SPI controller drivers. Either drivers capable of supporting
Quad mode should move to spi-mem framework or spi_xfer() interface needs to be
expanded.
Thanks for all the debugging! It would be great if you could try below
branch and let me know if it fixes all the issues.
If yes, I will remove RFC and post new series.
Sure, I'll try to find the time soon.
Had a quick test with both standard and tiny in SPL and both configs now
work on my board. I haven't tested SFDP as you said it does not works on
Cadence QSPI. (I tested compiling it though, and that works now.)
After enabling DEBUG in spi-mem.c, I see that we're changing to 4-byte
mode (via b7h) instead of using 4-byte opcodes. Unfortunately, this
conflicts with the boot rom using the default read opcose in 3-byte mode
on warm reboot.
Do you plan to change this or would this be fixed by parsing SFDP?
I used below hack to test SFDP with Cadence QSPI:
Just by accident, I saw that enabling the SFDP config does not seem to
break booting. But it still switches to 4-byte mode, so it probably just
fails to parse and continues the non-SFDP way?
diff --git a/drivers/spi/cadence_qspi_apb.c b/drivers/spi/cadence_qspi_apb.c
index a8af35203035..9dbf9aa7d20c 100644
--- a/drivers/spi/cadence_qspi_apb.c
+++ b/drivers/spi/cadence_qspi_apb.c
@@ -559,7 +559,7 @@ int cadence_qspi_apb_indirect_read_setup(struct
cadence_spi_platdata *plat,
/* Configure the opcode */
rd_reg = cmdbuf[0] << CQSPI_REG_RD_INSTR_OPCODE_LSB;
- if (rx_width & SPI_RX_QUAD)
+ if (rx_width & SPI_RX_QUAD && (cmdbuf[0] != 0x5a))
But this is Spansion-specific, right?
Regards,
Simon
/* Instruction and address at DQ0, data at DQ0-3. */
rd_reg |= CQSPI_INST_TYPE_QUAD <<
CQSPI_REG_RD_INSTR_TYPE_DATA_LSB;
Oh, and I think it's important to say that with your spi-nor-tiny code,
SPL code size is reduced by 1980 bytes for my config
(socfpga_socrates_defconfig)!
Thats good to know.
Regards,
Simon
Regards,
Simon
[1] https://github.com/r-vignesh/u-boot.git spi-nor-mig-patch-v1
--
Regards
Vignesh
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