The PS/2 bus defines the data and clock line be open drain, therefore
for both enforce the particular GPIO flags in the driver.
Without enforcing to flag at least the clock gpio as open drain we run
into the following warning:
WARNING: CPU: 1 PID: 40 at drivers/gpio/gpiolib.c:3175 gpiochip_enable_irq+0x54/0x90
gpiochip_enable_irq() warns on a GPIO being configured as output while
serving as IRQ source without being flagged as open drain.
Signed-off-by: Danilo Krummrich <danilokrummrich@dk-develop.de>
Link: https://lore.kernel.org/r/20220215180829.63543-4-danilokrummrich@dk-develop.de
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Sending the data before processing the stop bit from the device already
saves the data of the current xfer in case the stop bit is missed.
However, when TX xfers are enabled this introduces a race condition when
a peripheral driver using the bus immediately requests a TX xfer from IRQ
context.
Therefore the data must be send after receiving the stop bit, although
it is possible the data is lost when missing the stop bit.
Signed-off-by: Danilo Krummrich <danilokrummrich@dk-develop.de>
Link: https://lore.kernel.org/r/20220215160208.34826-5-danilokrummrich@dk-develop.de
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Actually, there's no extra clock pulse to wait for.
The assumption of an extra clock pulse was mistakenly derived from the
fact that by the time this driver was introduced the GPIO controller of
the test machine (bcm2835) generated spurious interrupts.
Since now spurious interrupts are handled properly this can and must be
removed in order to make TX xfers work properly.
While at it, remove duplicate gpiod_direction_input(). The data gpio
must already be configured to act as input when receiving the ACK bit.
This patch is tested with the original hardware (peripherals and board)
the driver was developed on.
Signed-off-by: Danilo Krummrich <danilokrummrich@dk-develop.de>
Link: https://lore.kernel.org/r/20220215160208.34826-4-danilokrummrich@dk-develop.de
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Using jiffies for the IRQ timekeeping is not sufficient for two reasons:
(1) Usually jiffies have a resolution of 1ms to 10ms. The IRQ intervals
based on the clock frequency of PS2 protocol specification (10kHz -
16.7kHz) are between ~60us and 100us only. Therefore only those IRQ
intervals can be detected which are either at the end of a transfer
or are overly delayed. While this is sufficient in most cases, since
we have quite a lot of ways to detect faulty transfers, it can
produce false positives in rare cases: When the jiffies value
changes right between two interrupt that are in time, we wrongly
assume that we missed one or more clock cycles.
(2) Some gpio controllers (e.g. the one in the bcm283x chips) may generate
spurious IRQs when processing interrupts in the frequency given by PS2
devices.
Both issues can be fixed by using ktime resolution for IRQ timekeeping.
However, it is still possible to miss clock cycles without detecting
them. When the PS2 device generates the falling edge of the clock signal
we have between ~30us and 50us to sample the data line, because after
this time we reach the next rising edge at which the device changes the
data signal already. But, the only thing we can detect is whether the
IRQ interval is within the given period. Therefore it is possible to
have an IRQ latency greater than ~30us to 50us, sample the wrong bit on
the data line and still be on time with the next IRQ. However, this can
only happen when within a given transfer the IRQ latency increases
slowly.
___ ______ ______ ______ ___
\ / \ / \ / \ /
\ / \ / \ / \ /
\______/ \______/ \______/ \______/
|-----------------| |--------|
60us/100us 30us/50us
Signed-off-by: Danilo Krummrich <danilokrummrich@dk-develop.de>
Link: https://lore.kernel.org/r/20220215160208.34826-3-danilokrummrich@dk-develop.de
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Pull tty/serial driver updates from Greg KH:
"Here is the big set of tty/serial driver updates for 5.17-rc1.
Nothing major in here, just lots of good updates and fixes, including:
- more tty core cleanups from Jiri as well as mxser driver cleanups.
This is the majority of the core diffstat
- tty documentation updates from Jiri
- platform_get_irq() updates
- various serial driver updates for new features and hardware
- fifo usage for 8250 console, reducing cpu load a lot
- LED fix for keyboards, long-time bugfix that went through many
revisions
- minor cleanups
All have been in linux-next for a while with no reported problems"
* tag 'tty-5.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (119 commits)
serial: core: Keep mctrl register state and cached copy in sync
serial: stm32: correct loop for dma error handling
serial: stm32: fix flow control transfer in DMA mode
serial: stm32: rework TX DMA state condition
serial: stm32: move tx dma terminate DMA to shutdown
serial: pl011: Drop redundant DTR/RTS preservation on close/open
serial: pl011: Drop CR register reset on set_termios
serial: pl010: Drop CR register reset on set_termios
serial: liteuart: fix MODULE_ALIAS
serial: 8250_bcm7271: Fix return error code in case of dma_alloc_coherent() failure
Revert "serdev: BREAK/FRAME/PARITY/OVERRUN notification prototype V2"
tty: goldfish: Use platform_get_irq() to get the interrupt
serdev: BREAK/FRAME/PARITY/OVERRUN notification prototype V2
tty: serial: meson: Drop the legacy compatible strings and clock code
serial: pmac_zilog: Use platform_get_irq() to get the interrupt
serial: bcm63xx: Use platform_get_irq() to get the interrupt
serial: ar933x: Use platform_get_irq() to get the interrupt
serial: vt8500: Use platform_get_irq() to get the interrupt
serial: altera_jtaguart: Use platform_get_irq_optional() to get the interrupt
serial: pxa: Use platform_get_irq() to get the interrupt
...
Pull input fixes from Dmitry Torokhov:
"A few small updates to drivers.
Of note we are now deferring probes of i8042 on some Asus devices as
the controller is not ready to respond to queries first time around
when the driver is compiled into the kernel"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
Input: elants_i2c - do not check Remark ID on eKTH3900/eKTH5312
Input: atmel_mxt_ts - fix double free in mxt_read_info_block
Input: goodix - fix memory leak in goodix_firmware_upload
Input: goodix - add id->model mapping for the "9111" model
Input: goodix - try not to touch the reset-pin on x86/ACPI devices
Input: i8042 - enable deferred probe quirk for ASUS UM325UA
Input: elantech - fix stack out of bound access in elantech_change_report_id()
Input: iqs626a - prohibit inlining of channel parsing functions
Input: i8042 - add deferred probe support
We've got a bug report about the non-working keyboard on ASUS ZenBook
UX425UA. It seems that the PS/2 device isn't ready immediately at
boot but takes some seconds to get ready. Until now, the only
workaround is to defer the probe, but it's available only when the
driver is a module. However, many distros, including openSUSE as in
the original report, build the PS/2 input drivers into kernel, hence
it won't work easily.
This patch adds the support for the deferred probe for i8042 stuff as
a workaround of the problem above. When the deferred probe mode is
enabled and the device couldn't be probed, it'll be repeated with the
standard deferred probe mechanism.
The deferred probe mode is enabled either via the new option
i8042.probe_defer or via the quirk table entry. As of this patch, the
quirk table contains only ASUS ZenBook UX425UA.
The deferred probe part is based on Fabio's initial work.
BugLink: https://bugzilla.suse.com/show_bug.cgi?id=1190256
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Tested-by: Samuel Čavoj <samuel@cavoj.net>
Link: https://lore.kernel.org/r/20211117063757.11380-1-tiwai@suse.de
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Pull input updates from Dmitry Torokhov:
"Just one new driver (Cypress StreetFighter touchkey), and no input
core changes this time.
Plus various fixes and enhancements to existing drivers"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input: (54 commits)
Input: iforce - fix control-message timeout
Input: wacom_i2c - use macros for the bit masks
Input: ili210x - reduce sample period to 15ms
Input: ili210x - improve polled sample spacing
Input: ili210x - special case ili251x sample read out
Input: elantench - fix misreporting trackpoint coordinates
Input: synaptics-rmi4 - Fix device hierarchy
Input: i8042 - Add quirk for Fujitsu Lifebook T725
Input: cap11xx - add support for cap1206
Input: remove unused header <linux/input/cy8ctmg110_pdata.h>
Input: ili210x - add ili251x firmware update support
Input: ili210x - export ili251x version details via sysfs
Input: ili210x - use resolution from ili251x firmware
Input: pm8941-pwrkey - respect reboot_mode for warm reset
reboot: export symbol 'reboot_mode'
Input: max77693-haptic - drop unneeded MODULE_ALIAS
Input: cpcap-pwrbutton - do not set input parent explicitly
Input: max8925_onkey - don't mark comment as kernel-doc
Input: ads7846 - do not attempt IRQ workaround when deferring probe
Input: ads7846 - use input_set_capability()
...
Pull input updates from Dmitry Torokhov:
- several device tree bindings for input devices have been converted to
yaml
- dropped no longer used ixp4xx-beeper and CSR Prima2 PWRC drivers
- analog joystick has been converted to use ktime API and no longer
warn about low resolution timers
- a few driver fixes
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input: (24 commits)
Input: analog - always use ktime functions
Input: mms114 - support MMS134S
Input: elan_i2c - reduce the resume time for controller in Whitebox
Input: edt-ft5x06 - added case for EDT EP0110M09
Input: adc-keys - drop bogus __refdata annotation
Input: Fix spelling mistake in Kconfig "useable" -> "usable"
Input: Fix spelling mistake in Kconfig "Modul" -> "Module"
Input: remove dead CSR Prima2 PWRC driver
Input: adp5589-keys - use the right header
Input: adp5588-keys - use the right header
dt-bindings: input: tsc2005: Convert to YAML schema
Input: ep93xx_keypad - prepare clock before using it
dt-bindings: input: sun4i-lradc: Add wakeup-source
dt-bindings: input: Convert Regulator Haptic binding to a schema
dt-bindings: input: Convert Pixcir Touchscreen binding to a schema
dt-bindings: input: Convert ChipOne ICN8318 binding to a schema
Input: pm8941-pwrkey - fix comma vs semicolon issue
dt-bindings: power: reset: qcom-pon: Convert qcom PON binding to yaml
dt-bindings: input: pm8941-pwrkey: Convert pm8941 power key binding to yaml
dt-bindings: power: reset: Change 'additionalProperties' to true
...
Pull parisc architecture updates from Helge Deller:
- Fix a kernel crash when a signal is delivered to bad userspace stack
- Fix fall-through warnings in math-emu code
- Increase size of gcc stack frame check
- Switch coding from 'pci_' to 'dma_' API
- Make struct parisc_driver::remove() return void
- Some parisc related Makefile changes
- Minor cleanups, e.g. change to octal permissions, fix macro
collisions, fix PMD_ORDER collision, replace spaces with tabs
* tag 'for-5.15/parisc' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
parisc: math-emu: Fix fall-through warnings
parisc: fix crash with signals and alloca
parisc: Fix compile failure when building 64-bit kernel natively
parisc: ccio-dma.c: Added tab instead of spaces
parisc/parport_gsc: switch from 'pci_' to 'dma_' API
parisc: move core-y in arch/parisc/Makefile to arch/parisc/Kbuild
parisc: switch from 'pci_' to 'dma_' API
parisc: Make struct parisc_driver::remove() return void
parisc: remove unused arch/parisc/boot/install.sh and its phony target
parisc: Rename PMD_ORDER to PMD_TABLE_ORDER
parisc: math-emu: Avoid "fmt" macro collision
parisc: Increase size of gcc stack frame check
parisc: Replace symbolic permissions with octal permissions
The caller of this function (parisc_driver_remove() in
arch/parisc/kernel/drivers.c) ignores the return value, so better don't
return any value at all to not wake wrong expectations in driver authors.
The only function that could return a non-zero value before was
ipmi_parisc_remove() which returns the return value of
ipmi_si_remove_by_dev(). Make this function return void, too, as for all
other callers the value is ignored, too.
Also fold in a small checkpatch fix for:
WARNING: Unnecessary space before function pointer arguments
+ void (*remove) (struct parisc_device *dev);
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> (for drivers/input)
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Acked-by: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Helge Deller <deller@gmx.de>
This reverts commit 81c7c0a350. The idea
to make write method mandatory was flawed as several client drivers
(such as atkbd) check for presence of write() method to adjust behavior
of the driver.
Reported-by: Nathan Chancellor <nathan@kernel.org>
Reported-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Pull tty / serial updates from Greg KH:
"Here is the big set of tty and serial driver patches for 5.14-rc1.
A bit more than normal, but nothing major, lots of cleanups.
Highlights are:
- lots of tty api cleanups and mxser driver cleanups from Jiri
- build warning fixes
- various serial driver updates
- coding style cleanups
- various tty driver minor fixes and updates
- removal of broken and disable r3964 line discipline (finally!)
All of these have been in linux-next for a while with no reported
issues"
* tag 'tty-5.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (227 commits)
serial: mvebu-uart: remove unused member nb from struct mvebu_uart
arm64: dts: marvell: armada-37xx: Fix reg for standard variant of UART
dt-bindings: mvebu-uart: fix documentation
serial: mvebu-uart: correctly calculate minimal possible baudrate
serial: mvebu-uart: do not allow changing baudrate when uartclk is not available
serial: mvebu-uart: fix calculation of clock divisor
tty: make linux/tty_flip.h self-contained
serial: Prefer unsigned int to bare use of unsigned
serial: 8250: 8250_omap: Fix possible interrupt storm on K3 SoCs
serial: qcom_geni_serial: use DT aliases according to DT bindings
Revert "tty: serial: Add UART driver for Cortina-Access platform"
tty: serial: Add UART driver for Cortina-Access platform
MAINTAINERS: add me back as mxser maintainer
mxser: Documentation, fix typos
mxser: Documentation, make the docs up-to-date
mxser: Documentation, remove traces of callout device
mxser: introduce mxser_16550A_or_MUST helper
mxser: rename flags to old_speed in mxser_set_serial_info
mxser: use port variable in mxser_set_serial_info
mxser: access info->MCR under info->slock
...
