The UART DM controller supports different channel data packing modes,
either the 4-character packing mode (where 32-bit are read/written at once)
or the single-character mode (where only a single character is read/written
at a time). The 4-character mode can be more efficient, but the
single-character mode is much easier to implement.
At the moment, serial_msm uses the 4-character mode. Since the
dm_serial_ops operate on one character at the time, the code goes through
quite some hoops in order to break this down to single characters. This
code is prone to race conditions (e.g. priv->chars_cnt is read from the
registers, then a command is issued, what if another char came in
inbetween?). It also seems to cause another subtle issue with autoboot:
Unlike the previous autoboot failures that happened when UART was
disconnected, this problem occurs when UART is connected and open in a
terminal: For EFI boot, the console size is queried in efi_console.c
query_console_serial() by sending an ANSI escape code via UART. For some
reason, with the current driver we get yet another 0x00 byte (UART break
event?) when reading the reply from serial input. Because of that, reading
the console size fails in efi_console.c, the actual reply remains in the
UART buffer, and later the boot flow aborts because it detects input after
printing a prompt.
Rather than trying to fix the issue in the current complicated approach,
switch the driver to use the single-character mode. This is simple and
straightforward to implement without race conditions:
- We write one character at a time to UARTDM_TF, as long as the TX FIFO
has space available (TX_READY). To flush the console before starting
Linux, we wait for TX_EMPTY.
- We read one character at a time from UARTDM_RF and strip off the
additional error information (assuming there is something in the
RX FIFO, as indicated by RX_READY).
In this mode, querying the serial console size works and autoboot is no
longer interrupted. The overall code is also much shorter.
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Stephan Gerhold <stephan.gerhold@linaro.org>
Tested-by: Alexey Minnekhanov <alexeymin@minlexx.ru>
Acked-by: Sumit Garg <sumit.garg@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20250908-db410c-autoboot-fixes-v2-6-316ed98e0143@linaro.org
Signed-off-by: Casey Connolly <kcxt@postmarketos.org>
There have been issues with autoboot on DB410c for years, where autoboot
gets interrupted by spurious input on the UART console. Back in 2021, I've
tried to fix this by inserting a delay before UART initialization, but it
has turned out this is not working reliably either.
It looks like the root cause has always been the lack of bias-pull-up,
which was causing the RX line to be floating when UART is disconnected.
The delay does not seem to be needed anymore when applying bias-pull-up,
so drop it again in favor of the proper fix.
This reverts commit ad7e967738.
Signed-off-by: Stephan Gerhold <stephan.gerhold@linaro.org>
Tested-by: Alexey Minnekhanov <alexeymin@minlexx.ru>
Acked-by: Sumit Garg <sumit.garg@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20250908-db410c-autoboot-fixes-v2-2-316ed98e0143@linaro.org
Signed-off-by: Casey Connolly <kcxt@postmarketos.org>
The GPIOs on PM6350 work fine using the qcom_spmi_gpio driver and
enables the use of the Volume Up button Fairphone 4 smartphone.
Signed-off-by: Luca Weiss <luca.weiss@fairphone.com>
Add the pm6150l regulator data found on the Qualcomm SM6350 platform.
The tables are imported from the Linux driver. The SMPS regulators were
not added now.
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Luca Weiss <luca.weiss@fairphone.com>
Add support for TLMM pin controller block (Top Level Mode Multiplexer)
on SM6350 SoC, with support for special pins.
Correct pin configuration is required for working debug UART and eMMC/SD
cards.
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Luca Weiss <luca.weiss@fairphone.com>
This reverts commit 644b4650ee.
While the intention of the above commit is correct, it leads to test
failures in CI that need to be addressed at the same time.
Signed-off-by: Tom Rini <trini@konsulko.com>
This driver references the get_timer macro while relying on an
indirection inclusion of <time.h>. Add the missing include directly.
Signed-off-by: Tom Rini <trini@konsulko.com>
A few spi drivers cannot build without access to some platform
specific header files. Express those requirements in Kconfig as well.
Signed-off-by: Tom Rini <trini@konsulko.com>
A few clock drivers cannot build without access to some platform
specific header files. Express those requirements in Kconfig as well.
Signed-off-by: Tom Rini <trini@konsulko.com>
There is nothing x86-centric in this include file, and moving it will
allow for some drivers to be compile-tested on sandbox.
Signed-off-by: Tom Rini <trini@konsulko.com>
When printing the contents of an lbaint_t variable we need to use LBAF
to print it in order to get the correct format type depending on 32 or
64bit-ness.
Signed-off-by: Tom Rini <trini@konsulko.com>
When printing the contents of an size_t variable we need to use z prefix
to the format character in order to get the correct format type
depending on 32 or 64bit-ness.
Signed-off-by: Tom Rini <trini@konsulko.com>
This feature requires that CFG_SYS_FLASH_BASE is defined and this in
turn is only done in the case of FLASH_CFI_DRIVER && !CFI_FLASH or in
other words, when DM_MTD is not enabled.
Signed-off-by: Tom Rini <trini@konsulko.com>
The function mtd_read_oob_bf is called by cmd/nand.c but does not have a
prototype in any header. Add this to include/linux/mtd/mtd.h as that is
the most logical place currently.
Fixes: 1fac577207 ("nand: Add a watch command")
Signed-off-by: Tom Rini <trini@konsulko.com>
In this header we make direct references to some dm/device.h functions
while not including the header directly. Add the missing include.
Signed-off-by: Tom Rini <trini@konsulko.com>
In nand_wait_ready there is a loop that includes a NULL check for
chip->dev_ready before it is dereferenced. Use a NULL check once the
loop is exited as well to cover the case where it exits due to a timeout
and it is therefore not known if chip->dev_ready is NULL or not.
This issue found by Smatch.
Signed-off-by: Andrew Goodbody <andrew.goodbody@linaro.org>
Reviewed-by: Michael Trimarchi <michael@amarulasolutions.com>
ret maybe used uninitialised in some cases so instead
initialise it first to prevent this.
This issue was found by Smatch.
Fixes: 9671243e8d (cmd: mtd: Use the subcmd infrastructure to declare mtd sub-commands)
Signed-off-by: Andrew Goodbody <andrew.goodbody@linaro.org>
Reviewed-by: Quentin Schulz <quentin.schulz@cherry.de>
