[PATCH v3] input: Add support for ChipOne icn8318 based touchscreens
Hans de Goede
hdegoede at redhat.com
Tue Mar 10 10:05:33 PDT 2015
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>
---
Changes in v2:
-Fix spurious events after a close + open of the evdev node.
Changes in v3:
-Add a msleep after waking the device on open, to wait for it to be ready
for i2c communications, otherwise we get communication errors on device open
---
.../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 | 318 +++++++++++++++++++++
6 files changed, 386 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 389ca13..b5dea36 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..d5c913a
--- /dev/null
+++ b/drivers/input/touchscreen/chipone_icn8318.c
@@ -0,0 +1,318 @@
+/*
+ * 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/delay.h>
+#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;
+/* The difference between 2 and 3 is unclear */
+#define ICN8318_EVENT_NO_DATA 1 /* No finger seen yet since wakeup */
+#define ICN8318_EVENT_UPDATE1 2 /* New or updated coordinates */
+#define ICN8318_EVENT_UPDATE2 3 /* New or updated coordinates */
+#define ICN8318_EVENT_END 4 /* Finger lifted */
+} __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 inline bool icn8318_touch_active(u8 event)
+{
+ return (event == ICN8318_EVENT_UPDATE1) ||
+ (event == ICN8318_EVENT_UPDATE2);
+}
+
+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];
+ bool act = icn8318_touch_active(touch->event);
+
+ input_mt_slot(data->input, touch->slot);
+ input_mt_report_slot_state(data->input, MT_TOOL_FINGER, act);
+ if (!act)
+ 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);
+
+ gpiod_set_value_cansleep(data->wake_gpio, 1);
+ msleep(20);
+ enable_irq(data->client->irq);
+
+ 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-swapped-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");
--
2.3.1
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