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authorIrina Tirdea2015-12-17 15:57:34 -0800
committerDmitry Torokhov2015-12-17 17:11:52 -0800
commitec6e1b4082d9f5b0858ce33169a1c22a27a982f6 (patch)
treea16efc75f25cac078c60f88e4978599f63c5a070 /crypto/cbc.c
parenta779fbc6c931007559b74fd74c2dc7b1c25bac33 (diff)
Input: goodix - reset device at init
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-gpios" property and the reset pin configuration is read from the "reset-gpios" 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-gpios", Package() {^STAC, 0, 0, 0 }}, Package (2) {"reset-gpios", Package() {^STAC, 1, 0, 0 }}, ... } } Signed-off-by: Octavian Purdila <octavian.purdila@intel.com> Signed-off-by: Irina Tirdea <irina.tirdea@intel.com> Acked-by: Rob Herring <robh@kernel.org> Acked-by: Bastien Nocera <hadess@hadess.net> Tested-by: Bastien Nocera <hadess@hadess.net> Tested-by: Aleksei Mamlin <mamlinav@gmail.com> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Diffstat (limited to 'crypto/cbc.c')
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