On Mon, Oct 12, 2015 at 06:24:30PM +0300, 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> > Acked-by: Bastien Nocera <hadess@xxxxxxxxxx> > Tested-by: Bastien Nocera <hadess@xxxxxxxxxx> > Tested-by: Aleksei Mamlin <mamlinav@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 > + - reset-gpio : GPIO pin used for reset > > Example: > > @@ -23,6 +25,9 @@ Example: > reg = <0x5d>; > interrupt-parent = <&gpio>; > interrupts = <0 0>; > + > + irq-gpio = <&gpio1 0 0>; > + reset-gpio = <&gpio1 1 0>; > }; > > /* ... */ > diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig > index 771d95c..76f5a9d 100644 > --- a/drivers/input/touchscreen/Kconfig > +++ b/drivers/input/touchscreen/Kconfig > @@ -324,6 +324,7 @@ config TOUCHSCREEN_FUJITSU > config TOUCHSCREEN_GOODIX > tristate "Goodix I2C touchscreen" > depends on I2C > + depends on GPIOLIB > help > Say Y here if you have the Goodix touchscreen (such as one > installed in Onda v975w tablets) connected to your > diff --git a/drivers/input/touchscreen/goodix.c b/drivers/input/touchscreen/goodix.c > index 56d0330..87304ac 100644 > --- a/drivers/input/touchscreen/goodix.c > +++ b/drivers/input/touchscreen/goodix.c > @@ -16,6 +16,7 @@ > > #include <linux/kernel.h> > #include <linux/dmi.h> > +#include <linux/gpio.h> > #include <linux/i2c.h> > #include <linux/input.h> > #include <linux/input/mt.h> > @@ -37,8 +38,13 @@ struct goodix_ts_data { > unsigned int int_trigger_type; > bool rotated_screen; > int cfg_len; > + struct gpio_desc *gpiod_int; > + struct gpio_desc *gpiod_rst; > }; > > +#define GOODIX_GPIO_INT_NAME "irq" > +#define GOODIX_GPIO_RST_NAME "reset" > + > #define GOODIX_MAX_HEIGHT 4096 > #define GOODIX_MAX_WIDTH 4096 > #define GOODIX_INT_TRIGGER 1 > @@ -237,6 +243,88 @@ static irqreturn_t goodix_ts_irq_handler(int irq, void *dev_id) > return IRQ_HANDLED; > } > > +static int goodix_int_sync(struct goodix_ts_data *ts) > +{ > + int error; > + > + error = gpiod_direction_output(ts->gpiod_int, 0); > + if (error) > + return error; > + msleep(50); /* T5: 50ms */ > + > + return gpiod_direction_input(ts->gpiod_int); > +} > + > +/** > + * goodix_reset - Reset device during power on > + * > + * @ts: goodix_ts_data pointer > + */ > +static int goodix_reset(struct goodix_ts_data *ts) > +{ > + int error; > + > + /* begin select I2C slave addr */ > + error = gpiod_direction_output(ts->gpiod_rst, 0); > + if (error) > + return error; > + msleep(20); /* T2: > 10ms */ > + /* HIGH: 0x28/0x29, LOW: 0xBA/0xBB */ > + error = gpiod_direction_output(ts->gpiod_int, ts->client->addr == 0x14); > + if (error) > + return error; > + usleep_range(100, 2000); /* T3: > 100us */ > + error = gpiod_direction_output(ts->gpiod_rst, 1); > + if (error) > + return error; > + usleep_range(6000, 10000); /* T4: > 5ms */ > + /* end select I2C slave addr */ > + error = gpiod_direction_input(ts->gpiod_rst); > + if (error) > + return error; > + return goodix_int_sync(ts); > +} > + > +/** > + * goodix_get_gpio_config - Get GPIO config from ACPI/DT > + * > + * @ts: goodix_ts_data pointer > + */ > +static int goodix_get_gpio_config(struct goodix_ts_data *ts) > +{ > + int error; > + struct device *dev; > + struct gpio_desc *gpiod; > + > + if (!ts->client) > + return -EINVAL; > + dev = &ts->client->dev; > + > + /* Get the interrupt GPIO pin number */ > + gpiod = devm_gpiod_get(dev, GOODIX_GPIO_INT_NAME, GPIOD_IN); Why isn't this devm_gpiod_get_optional()? Then you would not need to clobber the return value down in goodix_ts_probe(). I can fix it up locally. Thanks. -- Dmitry -- 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