[PATCH 2/2] input: Add support for ChipOne icn8318 based touchscreens
Hans de Goede
hdegoede at redhat.com
Mon Feb 23 07:46:11 PST 2015
Hi,
On 23-02-15 16:28, Hans de Goede wrote:
> The ChipOne icn8318 is an i2c capacitive touchscreen controller typically
> used in cheap android tablets, this commit adds a driver for it.
>
> Signed-off-by: Hans de Goede <hdegoede at redhat.com>
And just when I think I'm done I discover there are spurious evdev events being
send after a close + open of the evdev node. I'll send a v2 of this set fixing this
shortly.
Regards,
Hans
> ---
> .../bindings/input/touchscreen/chipone_icn8318.txt | 46 +++
> .../devicetree/bindings/vendor-prefixes.txt | 1 +
> MAINTAINERS | 7 +
> drivers/input/touchscreen/Kconfig | 13 +
> drivers/input/touchscreen/Makefile | 1 +
> drivers/input/touchscreen/chipone_icn8318.c | 307 +++++++++++++++++++++
> 6 files changed, 375 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/input/touchscreen/chipone_icn8318.txt
> create mode 100644 drivers/input/touchscreen/chipone_icn8318.c
>
> diff --git a/Documentation/devicetree/bindings/input/touchscreen/chipone_icn8318.txt b/Documentation/devicetree/bindings/input/touchscreen/chipone_icn8318.txt
> new file mode 100644
> index 0000000..b405493
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/input/touchscreen/chipone_icn8318.txt
> @@ -0,0 +1,46 @@
> +* ChipOne icn8318 I2C touchscreen controller
> +
> +Required properties:
> + - compatible : "chipone,icn8318"
> + - reg : I2C slave address of the chip (0x40)
> + - interrupt-parent : a phandle pointing to the interrupt controller
> + serving the interrupt for this chip
> + - interrupts : interrupt specification for the icn8318 interrupt
> + - wake-gpios : GPIO specification for the WAKE input
> + - touchscreen-size-x : horizontal resolution of touchscreen (in pixels)
> + - touchscreen-size-y : vertical resolution of touchscreen (in pixels)
> +
> +Optional properties:
> + - pinctrl-names : should be "default"
> + - pinctrl-0: : a phandle pointing to the pin settings for the
> + control gpios
> + - touchscreen-fuzz-x : horizontal noise value of the absolute input
> + device (in pixels)
> + - touchscreen-fuzz-y : vertical noise value of the absolute input
> + device (in pixels)
> + - touchscreen-inverted-x : X axis is inverted (boolean)
> + - touchscreen-inverted-y : Y axis is inverted (boolean)
> + - touchscreen-swap-x-y : X and Y axis are swapped (boolean)
> + Swapping is done after inverting the axis
> +
> +Example:
> +
> +i2c at 00000000 {
> + /* ... */
> +
> + chipone_icn8318 at 40 {
> + compatible = "chipone,icn8318";
> + reg = <0x40>;
> + interrupt-parent = <&pio>;
> + interrupts = <9 IRQ_TYPE_EDGE_FALLING>; /* EINT9 (PG9) */
> + pinctrl-names = "default";
> + pinctrl-0 = <&ts_wake_pin_p66>;
> + wake-gpios = <&pio 1 3 GPIO_ACTIVE_HIGH>; /* PB3 */
> + touchscreen-size-x = <800>;
> + touchscreen-size-y = <480>;
> + touchscreen-inverted-x;
> + touchscreen-swap-x-y;
> + };
> +
> + /* ... */
> +};
> diff --git a/Documentation/devicetree/bindings/vendor-prefixes.txt b/Documentation/devicetree/bindings/vendor-prefixes.txt
> index cc8848f..a4cb25e 100644
> --- a/Documentation/devicetree/bindings/vendor-prefixes.txt
> +++ b/Documentation/devicetree/bindings/vendor-prefixes.txt
> @@ -35,6 +35,7 @@ capella Capella Microsystems, Inc
> cavium Cavium, Inc.
> cdns Cadence Design Systems Inc.
> chipidea Chipidea, Inc
> +chipone ChipOne
> chipspark ChipSPARK
> chrp Common Hardware Reference Platform
> chunghwa Chunghwa Picture Tubes Ltd.
> diff --git a/MAINTAINERS b/MAINTAINERS
> index ddc5a8c..d39304c 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -2512,6 +2512,13 @@ L: linux-usb at vger.kernel.org
> S: Maintained
> F: drivers/usb/chipidea/
>
> +CHIPONE ICN8318 I2C TOUCHSCREEN DRIVER
> +M: Hans de Goede <hdegoede at redhat.com>
> +L: linux-input at vger.kernel.org
> +S: Maintained
> +F: Documentation/devicetree/bindings/input/touchscreen/chipone_icn8318.txt
> +F: drivers/input/touchscreen/chipone_icn8318.c
> +
> CHROME HARDWARE PLATFORM SUPPORT
> M: Olof Johansson <olof at lixom.net>
> S: Maintained
> diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
> index 5891752..19ca23e 100644
> --- a/drivers/input/touchscreen/Kconfig
> +++ b/drivers/input/touchscreen/Kconfig
> @@ -140,6 +140,19 @@ config TOUCHSCREEN_BU21013
> To compile this driver as a module, choose M here: the
> module will be called bu21013_ts.
>
> +config TOUCHSCREEN_CHIPONE_ICN8318
> + tristate "chipone icn8318 touchscreen controller"
> + depends on GPIOLIB
> + depends on I2C
> + depends on OF
> + help
> + Say Y here if you have a ChipOne icn8318 based I2C touchscreen.
> +
> + If unsure, say N.
> +
> + To compile this driver as a module, choose M here: the
> + module will be called chipone_icn8318.
> +
> config TOUCHSCREEN_CY8CTMG110
> tristate "cy8ctmg110 touchscreen"
> depends on I2C
> diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
> index 0242fea..9517ae4 100644
> --- a/drivers/input/touchscreen/Makefile
> +++ b/drivers/input/touchscreen/Makefile
> @@ -17,6 +17,7 @@ obj-$(CONFIG_TOUCHSCREEN_AR1021_I2C) += ar1021_i2c.o
> obj-$(CONFIG_TOUCHSCREEN_ATMEL_MXT) += atmel_mxt_ts.o
> obj-$(CONFIG_TOUCHSCREEN_AUO_PIXCIR) += auo-pixcir-ts.o
> obj-$(CONFIG_TOUCHSCREEN_BU21013) += bu21013_ts.o
> +obj-$(CONFIG_TOUCHSCREEN_CHIPONE_ICN8318) += chipone_icn8318.o
> obj-$(CONFIG_TOUCHSCREEN_CY8CTMG110) += cy8ctmg110_ts.o
> obj-$(CONFIG_TOUCHSCREEN_CYTTSP_CORE) += cyttsp_core.o
> obj-$(CONFIG_TOUCHSCREEN_CYTTSP_I2C) += cyttsp_i2c.o cyttsp_i2c_common.o
> diff --git a/drivers/input/touchscreen/chipone_icn8318.c b/drivers/input/touchscreen/chipone_icn8318.c
> new file mode 100644
> index 0000000..d47e7dd
> --- /dev/null
> +++ b/drivers/input/touchscreen/chipone_icn8318.c
> @@ -0,0 +1,307 @@
> +/*
> + * Driver for ChipOne icn8318 i2c touchscreen controller
> + *
> + * Copyright (c) 2015 Red Hat Inc.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * Red Hat authors:
> + * Hans de Goede <hdegoede at redhat.com>
> + */
> +
> +#include <linux/gpio/consumer.h>
> +#include <linux/interrupt.h>
> +#include <linux/i2c.h>
> +#include <linux/input.h>
> +#include <linux/input/mt.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +
> +#define ICN8318_REG_POWER 4
> +#define ICN8318_REG_TOUCHDATA 16
> +
> +#define ICN8318_POWER_ACTIVE 0
> +#define ICN8318_POWER_MONITOR 1
> +#define ICN8318_POWER_HIBERNATE 2
> +
> +#define ICN8318_MAX_TOUCHES 5
> +
> +struct icn8318_touch {
> + __u8 slot;
> + __be16 x;
> + __be16 y;
> + __u8 pressure; /* Seems more like finger width then pressure really */
> + __u8 event;
> +#define ICN8318_EVENT_UPDATE 3
> +#define ICN8318_EVENT_END 4
> +} __packed;
> +
> +struct icn8318_touch_data {
> + __u8 softbutton;
> + __u8 touch_count;
> + struct icn8318_touch touches[ICN8318_MAX_TOUCHES];
> +} __packed;
> +
> +struct icn8318_data {
> + struct i2c_client *client;
> + struct input_dev *input;
> + struct gpio_desc *wake_gpio;
> + u32 max_x;
> + u32 max_y;
> + bool invert_x;
> + bool invert_y;
> + bool swap_x_y;
> +};
> +
> +static int icn8318_read_touch_data(struct i2c_client *client,
> + struct icn8318_touch_data *touch_data)
> +{
> + u8 reg = ICN8318_REG_TOUCHDATA;
> + struct i2c_msg msg[2] = {
> + {
> + .addr = client->addr,
> + .len = 1,
> + .buf = ®
> + },
> + {
> + .addr = client->addr,
> + .flags = I2C_M_RD,
> + .len = sizeof(struct icn8318_touch_data),
> + .buf = (u8 *)touch_data
> + }
> + };
> +
> + return i2c_transfer(client->adapter, msg, 2);
> +}
> +
> +static irqreturn_t icn8318_irq(int irq, void *dev_id)
> +{
> + struct icn8318_data *data = dev_id;
> + struct device *dev = &data->client->dev;
> + struct icn8318_touch_data touch_data;
> + int i, ret, x, y;
> +
> + ret = icn8318_read_touch_data(data->client, &touch_data);
> + if (ret < 0) {
> + dev_err(dev, "Error reading touch data: %d\n", ret);
> + return IRQ_HANDLED;
> + }
> +
> + if (touch_data.softbutton) {
> + /*
> + * Other data is invalid when a softbutton is pressed.
> + * This needs some extra devicetree bindings to map the icn8318
> + * softbutton codes to evdev codes. Currently no known devices
> + * use this.
> + */
> + return IRQ_HANDLED;
> + }
> +
> + if (touch_data.touch_count > ICN8318_MAX_TOUCHES) {
> + dev_warn(dev, "Too much touches %d > %d\n",
> + touch_data.touch_count, ICN8318_MAX_TOUCHES);
> + touch_data.touch_count = ICN8318_MAX_TOUCHES;
> + }
> +
> + for (i = 0; i < touch_data.touch_count; i++) {
> + struct icn8318_touch *touch = &touch_data.touches[i];
> +
> + input_mt_slot(data->input, touch->slot);
> + input_mt_report_slot_state(data->input, MT_TOOL_FINGER,
> + touch->event != ICN8318_EVENT_END);
> + if (touch->event == ICN8318_EVENT_END)
> + continue;
> +
> + x = be16_to_cpu(touch->x);
> + y = be16_to_cpu(touch->y);
> +
> + if (data->invert_x)
> + x = data->max_x - x;
> +
> + if (data->invert_y)
> + y = data->max_y - y;
> +
> + if (!data->swap_x_y) {
> + input_event(data->input, EV_ABS, ABS_MT_POSITION_X, x);
> + input_event(data->input, EV_ABS, ABS_MT_POSITION_Y, y);
> + } else {
> + input_event(data->input, EV_ABS, ABS_MT_POSITION_X, y);
> + input_event(data->input, EV_ABS, ABS_MT_POSITION_Y, x);
> + }
> + }
> +
> + input_mt_sync_frame(data->input);
> + input_sync(data->input);
> +
> + return IRQ_HANDLED;
> +}
> +
> +static int icn8318_start(struct input_dev *dev)
> +{
> + struct icn8318_data *data = input_get_drvdata(dev);
> +
> + enable_irq(data->client->irq);
> + gpiod_set_value_cansleep(data->wake_gpio, 1);
> +
> + return 0;
> +}
> +
> +static void icn8318_stop(struct input_dev *dev)
> +{
> + struct icn8318_data *data = input_get_drvdata(dev);
> +
> + disable_irq(data->client->irq);
> + i2c_smbus_write_byte_data(data->client, ICN8318_REG_POWER,
> + ICN8318_POWER_HIBERNATE);
> + gpiod_set_value_cansleep(data->wake_gpio, 0);
> +}
> +
> +#ifdef CONFIG_PM_SLEEP
> +static int icn8318_suspend(struct device *dev)
> +{
> + struct icn8318_data *data = i2c_get_clientdata(to_i2c_client(dev));
> +
> + mutex_lock(&data->input->mutex);
> + if (data->input->users)
> + icn8318_stop(data->input);
> + mutex_unlock(&data->input->mutex);
> +
> + return 0;
> +}
> +
> +static int icn8318_resume(struct device *dev)
> +{
> + struct icn8318_data *data = i2c_get_clientdata(to_i2c_client(dev));
> +
> + mutex_lock(&data->input->mutex);
> + if (data->input->users)
> + icn8318_start(data->input);
> + mutex_unlock(&data->input->mutex);
> +
> + return 0;
> +}
> +#endif
> +
> +static SIMPLE_DEV_PM_OPS(icn8318_pm_ops, icn8318_suspend, icn8318_resume);
> +
> +static int icn8318_probe(struct i2c_client *client,
> + const struct i2c_device_id *id)
> +{
> + struct device *dev = &client->dev;
> + struct device_node *np = dev->of_node;
> + struct icn8318_data *data;
> + struct input_dev *input;
> + u32 fuzz_x = 0, fuzz_y = 0;
> + int error;
> +
> + if (!client->irq) {
> + dev_err(dev, "Error no irq specified\n");
> + return -EINVAL;
> + }
> +
> + data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
> + if (!data)
> + return -ENOMEM;
> +
> + data->wake_gpio = devm_gpiod_get(dev, "wake", GPIOD_OUT_LOW);
> + if (IS_ERR(data->wake_gpio)) {
> + error = PTR_ERR(data->wake_gpio);
> + if (error != -EPROBE_DEFER)
> + dev_err(dev, "Error getting wake gpio: %d\n", error);
> + return error;
> + }
> +
> + if (of_property_read_u32(np, "touchscreen-size-x", &data->max_x) ||
> + of_property_read_u32(np, "touchscreen-size-y", &data->max_y)) {
> + dev_err(dev, "Error touchscreen-size-x and/or -y missing\n");
> + return -EINVAL;
> + }
> + /* Optional */
> + of_property_read_u32(np, "touchscreen-fuzz-x", &fuzz_x);
> + of_property_read_u32(np, "touchscreen-fuzz-y", &fuzz_y);
> + data->invert_x = of_property_read_bool(np, "touchscreen-inverted-x");
> + data->invert_y = of_property_read_bool(np, "touchscreen-inverted-y");
> + data->swap_x_y = of_property_read_bool(np, "touchscreen-swap-x-y");
> +
> + input = devm_input_allocate_device(dev);
> + if (!input)
> + return -ENOMEM;
> +
> + input->name = client->name;
> + input->id.bustype = BUS_I2C;
> + input->open = icn8318_start;
> + input->close = icn8318_stop;
> + input->dev.parent = dev;
> +
> + if (!data->swap_x_y) {
> + input_set_abs_params(input, ABS_MT_POSITION_X, 0,
> + data->max_x, fuzz_x, 0);
> + input_set_abs_params(input, ABS_MT_POSITION_Y, 0,
> + data->max_y, fuzz_y, 0);
> + } else {
> + input_set_abs_params(input, ABS_MT_POSITION_X, 0,
> + data->max_y, fuzz_y, 0);
> + input_set_abs_params(input, ABS_MT_POSITION_Y, 0,
> + data->max_x, fuzz_x, 0);
> + }
> +
> + error = input_mt_init_slots(input, ICN8318_MAX_TOUCHES,
> + INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
> + if (error)
> + return error;
> +
> + data->client = client;
> + data->input = input;
> + input_set_drvdata(input, data);
> +
> + error = devm_request_threaded_irq(dev, client->irq, NULL, icn8318_irq,
> + IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
> + client->name, data);
> + if (error) {
> + dev_err(dev, "Error requesting irq: %d\n", error);
> + return error;
> + }
> +
> + /* Stop device till opened */
> + icn8318_stop(data->input);
> +
> + error = input_register_device(input);
> + if (error)
> + return error;
> +
> + i2c_set_clientdata(client, data);
> +
> + return 0;
> +}
> +
> +static const struct of_device_id icn8318_of_match[] = {
> + { .compatible = "chipone,icn8318" },
> + { }
> +};
> +MODULE_DEVICE_TABLE(of, icn8318_of_match);
> +
> +/* This is useless for OF-enabled devices, but it is needed by I2C subsystem */
> +static const struct i2c_device_id icn8318_i2c_id[] = {
> + { },
> +};
> +MODULE_DEVICE_TABLE(i2c, icn8318_i2c_id);
> +
> +static struct i2c_driver icn8318_driver = {
> + .driver = {
> + .owner = THIS_MODULE,
> + .name = "chipone_icn8318",
> + .pm = &icn8318_pm_ops,
> + .of_match_table = icn8318_of_match,
> + },
> + .probe = icn8318_probe,
> + .id_table = icn8318_i2c_id,
> +};
> +
> +module_i2c_driver(icn8318_driver);
> +
> +MODULE_DESCRIPTION("ChipOne icn8318 I2C Touchscreen Driver");
> +MODULE_AUTHOR("Hans de Goede <hdegoede at redhat.com>");
> +MODULE_LICENSE("GPL");
>
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