Linux mainline fork with MSM8998 patches | https://mainline.space | Currently supported devices:
OnePlus 5/5T, Xiaomi Mi 6, F(x)tec Pro¹ (2019 QX1000 model) & Sony Xperia XZ Premium (UNTESTED!)
29d7e05c5f
A read from a Winbond W25Q32FV SPI NOR memory chip on my MMP2 returns wrong data. It seems like SSE doesn't do the right thing on MMP2 at all. After enabling the SPI port back again, the FIFO reads return garbage. Things can be brought back to order by telling the PMU to reset the block. Here's a good transaction with said chip: # busybox devmem 0xd4035000 32 0x00001987 # SSCR0 # echo 0 >/sys/class/gpio/gpio46/value # (assert CS) # busybox devmem 0xd4035010 32 0x0000009f # SSDR (read ID command) # busybox devmem 0xd4035010 32 0x00000000 # SSDR # busybox devmem 0xd4035010 32 0x00000000 # SSDR # busybox devmem 0xd4035010 32 0x00000000 # SSDR # busybox devmem 0xd4035010 32 0x00000000 # SSDR # busybox devmem 0xd4035010 32 0x00000000 # SSDR # busybox devmem 0xd4035010 32 0x00000000 # SSDR # busybox devmem 0xd4035010 # SSDR 0x000000ff # busybox devmem 0xd4035010 # SSDR 0x000000ef # Correct response # busybox devmem 0xd4035010 # SSDR 0x00000040 # busybox devmem 0xd4035010 # SSDR 0x00000016 # busybox devmem 0xd4035010 # SSDR 0x00000000 # busybox devmem 0xd4035010 # SSDR 0x00000000 # busybox devmem 0xd4035010 # SSDR 0x00000000 # echo 1 >/sys/class/gpio/gpio46/value # (deassert CS) # Flipping off an on SSE, then running another transaction: # busybox devmem 0xd4035000 32 0x00001907 # SSCR0, SSE off # busybox devmem 0xd4035000 32 0x00001987 # SSCR0, SSE on # echo 0 >/sys/class/gpio/gpio46/value # (assert CS) # busybox devmem 0xd4035010 32 0x0000009f # SSDR (read ID command) # busybox devmem 0xd4035010 32 0x00000000 # SSDR # busybox devmem 0xd4035010 32 0x00000000 # SSDR # busybox devmem 0xd4035010 32 0x00000000 # SSDR # busybox devmem 0xd4035010 32 0x00000000 # SSDR # busybox devmem 0xd4035010 32 0x00000000 # SSDR # busybox devmem 0xd4035010 32 0x00000000 # SSDR # busybox devmem 0xd4035010 # SSDR 0x000000ff # busybox devmem 0xd4035010 # SSDR 0x000000ff # Garbage! # busybox devmem 0xd4035010 # SSDR 0x000000ff # Oh no # busybox devmem 0xd4035010 # SSDR 0x000000ff # busybox devmem 0xd4035010 # SSDR 0x000000ff # busybox devmem 0xd4035010 # SSDR 0x000000ff # busybox devmem 0xd4035010 # SSDR 0x000000ff # echo 1 >/sys/class/gpio/gpio46/value # (deassert CS) # Sometimes the response is not just ones, but something that looks like bits of a response from a previous transaction. I can't see a fix other than not touching the SSE altogether after the device is first brought up. Signed-off-by: Lubomir Rintel <lkundrak@v3.sk> Link: https://lore.kernel.org/r/20200118094031.327373-1-lkundrak@v3.sk Signed-off-by: Mark Brown <broonie@kernel.org> |
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| arch | ||
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| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
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| .clang-format | ||
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| README | ||
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.