> -----Original Message----- > From: Rob Herring [mailto:robh@xxxxxxxxxx] > Sent: 18 November, 2015 23:24 > To: Tirdea, Irina > Cc: Dmitry Torokhov; Bastien Nocera; Aleksei Mamlin; Karsten Merker; linux-input@xxxxxxxxxxxxxxx; Mark Rutland; Purdila, Octavian; > linux-kernel@xxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx > Subject: Re: [PATCH v10 2/8] Input: goodix - reset device at init > > On Wed, Nov 18, 2015 at 06:31:35PM +0200, Irina Tirdea wrote: > > After power on, it is recommended that the driver resets the device. > > The reset procedure timing is described in the datasheet and is used > > at device init (before writing device configuration) and > > for power management. It is a sequence of setting the interrupt > > and reset pins high/low at specific timing intervals. This procedure > > also includes setting the slave address to the one specified in the > > ACPI/device tree. > > > > This is based on Goodix datasheets for GT911 and GT9271 and on Goodix > > driver gt9xx.c for Android (publicly available in Android kernel > > trees for various devices). > > > > For reset the driver needs to control the interrupt and > > reset gpio pins (configured through ACPI/device tree). For devices > > that do not have the gpio pins properly declared, the functionality > > depending on these pins will not be available, but the device can still > > be used with basic functionality. > > > > For both device tree and ACPI, the interrupt gpio pin configuration is > > read from the "irq-gpio" property and the reset pin configuration is > > read from the "reset-gpio" property. For ACPI 5.1, named properties > > can be specified using the _DSD section. This functionality will not be > > available for devices that use indexed gpio pins declared in the _CRS > > section (we need to provide backward compatibility with devices > > that do not support using the interrupt gpio pin as output). > > > > For ACPI, the pins can be specified using ACPI 5.1: > > Device (STAC) > > { > > Name (_HID, "GDIX1001") > > ... > > > > Method (_CRS, 0, Serialized) > > { > > Name (RBUF, ResourceTemplate () > > { > > I2cSerialBus (0x0014, ControllerInitiated, 0x00061A80, > > AddressingMode7Bit, "\\I2C0", > > 0x00, ResourceConsumer, , > > ) > > > > GpioInt (Edge, ActiveHigh, Exclusive, PullNone, 0x0000, > > "\\I2C0", 0x00, ResourceConsumer, , > > ) > > { // Pin list > > 0 > > } > > > > GpioIo (Exclusive, PullDown, 0x0000, 0x0000, > > IoRestrictionOutputOnly, "\\I2C0", 0x00, > > ResourceConsumer, , > > ) > > { > > 1 > > } > > }) > > Return (RBUF) > > } > > > > Name (_DSD, Package () > > { > > ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"), > > Package () > > { > > Package (2) {"irq-gpio", Package() {^STAC, 0, 0, 0 }}, > > Package (2) {"reset-gpio", Package() {^STAC, 1, 0, 0 }}, > > ... > > } > > } > > > > Signed-off-by: Octavian Purdila <octavian.purdila@xxxxxxxxx> > > Signed-off-by: Irina Tirdea <irina.tirdea@xxxxxxxxx> > > --- > > .../bindings/input/touchscreen/goodix.txt | 5 + > > drivers/input/touchscreen/Kconfig | 1 + > > drivers/input/touchscreen/goodix.c | 101 +++++++++++++++++++++ > > 3 files changed, 107 insertions(+) > > > > diff --git a/Documentation/devicetree/bindings/input/touchscreen/goodix.txt > b/Documentation/devicetree/bindings/input/touchscreen/goodix.txt > > index 8ba98ee..7137881 100644 > > --- a/Documentation/devicetree/bindings/input/touchscreen/goodix.txt > > +++ b/Documentation/devicetree/bindings/input/touchscreen/goodix.txt > > @@ -12,6 +12,8 @@ Required properties: > > - reg : I2C address of the chip. Should be 0x5d or 0x14 > > - interrupt-parent : Interrupt controller to which the chip is connected > > - interrupts : Interrupt to which the chip is connected > > + - irq-gpio : GPIO pin used for IRQ > > Please note here why you need this in addition to just "interrupts". Ok. > Also, it should be irq-gpios instead. > > > + - reset-gpio : GPIO pin used for reset > > Should be reset-gpios instead. > I'll fix this, I wasn't aware that irq/reset-gpio is deprecated. Thanks, Irina > Rob -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
