| Message ID | 20210122200659.7404-1-digetx@gmail.com |
|---|---|
| Headers | show |
| Series | Support wakeup methods of Atmel maXTouch controllers | expand |
On Fri, Jan 22, 2021 at 9:07 PM Dmitry Osipenko <digetx@gmail.com> wrote: > According to datasheets, chips like mXT1386 have a WAKE line, it is used > to wake the chip up from deep sleep mode before communicating with it via > the I2C-compatible interface. > > If the WAKE line is connected to a GPIO line, the line must be asserted > 25 ms before the host attempts to communicate with the controller. If the > WAKE line is connected to the SCL pin, the controller will send a NACK on > the first attempt to address it, the host must then retry 25 ms later. > > Implement the wake-up methods in the driver. Touchscreen now works > properly on devices like Acer A500 tablet, fixing problems like this: > > atmel_mxt_ts 0-004c: __mxt_read_reg: i2c transfer failed (-121) > atmel_mxt_ts 0-004c: mxt_bootloader_read: i2c recv failed (-121) > atmel_mxt_ts 0-004c: Trying alternate bootloader address > atmel_mxt_ts 0-004c: mxt_bootloader_read: i2c recv failed (-121) > atmel_mxt_ts: probe of 0-004c failed with error -121 > > Signed-off-by: Jiada Wang <jiada_wang@mentor.com> > Signed-off-by: Dmitry Osipenko <digetx@gmail.com> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Yours, Linus Walleij
On Fri, 22 Jan 2021 23:06:57 +0300, Dmitry Osipenko wrote: > Some Atmel touchscreen controllers have a WAKE line that needs to be > asserted low in order to wake up controller from a deep sleep. Document > the wakeup methods and the new GPIO properties. > > Reviewed-by: Linus Walleij <linus.walleij@linaro.org> > Signed-off-by: Dmitry Osipenko <digetx@gmail.com> > --- > .../bindings/input/atmel,maxtouch.yaml | 29 +++++++++++++++++++ > include/dt-bindings/input/atmel-maxtouch.h | 10 +++++++ > 2 files changed, 39 insertions(+) > create mode 100644 include/dt-bindings/input/atmel-maxtouch.h > Reviewed-by: Rob Herring <robh@kernel.org>
Some Atmel maXTouch controllers, like mXT1386 and mXT3432S1 for example, have a WAKE line that needs to be asserted in order to wake controller from a deep sleep, otherwise it will be unusable. This series implements support for the wakeup methods in accordance to the mXT1386 datasheet [1], see page 29 (chapter "5.8 WAKE Line"). The mXT1386 is a widely used controller found on many older Android tablet devices. Touchscreen on Acer A500 tablet now works properly after this series. This patchset is a continuation of the work originally started by Jiada Wang [2]. [1] https://ww1.microchip.com/downloads/en/DeviceDoc/mXT1386_1vx_Datasheet_LX.pdf [2] https://patchwork.kernel.org/project/linux-input/list/?series=357875 Changelog: v4: - Improved commit message of the DT binding patch. No code changes. v3: - Added "default: 0" to the atmel,wakeup-method property in the binding. - Added r-b from Linus Walleij to the binding patch. - The wake-GPIO is now toggled on touchscreen's start/stop in order to allow it to sleep during suspend. Suggested by Linus Walleij. v2: - Fixed copy-paste bug in the code. Dmitry Osipenko (3): dt-bindings: input: atmel_mxt_ts: Document atmel,wakeup-method and WAKE line GPIO Input: atmel_mxt_ts - support wakeup methods ARM: tegra: acer-a500: Add atmel,wakeup-method property .../bindings/input/atmel,maxtouch.yaml | 29 +++++++ .../boot/dts/tegra20-acer-a500-picasso.dts | 3 + drivers/input/touchscreen/atmel_mxt_ts.c | 78 +++++++++++++++++++ include/dt-bindings/input/atmel-maxtouch.h | 10 +++ 4 files changed, 120 insertions(+) create mode 100644 include/dt-bindings/input/atmel-maxtouch.h