[PATCH v2] Input: Add support for FocalTech FT6236 touchscreen controller
From: Noralf TrÃnnes
Date: Thu Oct 01 2015 - 07:36:57 EST
This adds support for the FT6x06 and the FT6x36 family of
capacitive touch panel controllers, in particular the FT6236.
Signed-off-by: Noralf TrÃnnes <noralf@xxxxxxxxxxx>
---
The driver is based on:
https://github.com/adafruit/adafruit-raspberrypi-linux/blob/rpi-3.18.y/drivers/input/touchscreen/ft6x06_ts.c
Changes from v1:
Dmitry Torokhov:
s/ret/error/
reset gpio polarity should be encoded in DT/ACPI data
.../input/touchscreen/focaltech-ft6236.txt | 35 +++
.../devicetree/bindings/vendor-prefixes.txt | 1 +
drivers/input/touchscreen/Kconfig | 14 +
drivers/input/touchscreen/Makefile | 1 +
drivers/input/touchscreen/ft6236.c | 322 +++++++++++++++++++++
5 files changed, 373 insertions(+)
create mode 100644 Documentation/devicetree/bindings/input/touchscreen/focaltech-ft6236.txt
create mode 100644 drivers/input/touchscreen/ft6236.c
diff --git a/Documentation/devicetree/bindings/input/touchscreen/focaltech-ft6236.txt b/Documentation/devicetree/bindings/input/touchscreen/focaltech-ft6236.txt
new file mode 100644
index 0000000..777521d
--- /dev/null
+++ b/Documentation/devicetree/bindings/input/touchscreen/focaltech-ft6236.txt
@@ -0,0 +1,35 @@
+* FocalTech FT6236 I2C touchscreen controller
+
+Required properties:
+ - compatible : "focaltech,ft6236"
+ - reg : I2C slave address of the chip (0x38)
+ - interrupt-parent : a phandle pointing to the interrupt controller
+ serving the interrupt for this chip
+ - interrupts : interrupt specification for the touch controller
+ interrupt
+ - reset-gpios : GPIO specification for the RSTN input
+ - touchscreen-size-x : horizontal resolution of touchscreen (in pixels)
+ - touchscreen-size-y : vertical resolution of touchscreen (in pixels)
+
+Optional properties:
+ - 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-swapped-x-y: X and Y axis are swapped (boolean)
+ Swapping is done after inverting the axis
+
+Example:
+
+ ft6x06@38 {
+ compatible = "focaltech,ft6236";
+ reg = <0x38>;
+ interrupt-parent = <&gpio>;
+ interrupts = <23 2>;
+ touchscreen-size-x = <320>;
+ touchscreen-size-y = <480>;
+ touchscreen-inverted-x;
+ touchscreen-swapped-x-y;
+ };
diff --git a/Documentation/devicetree/bindings/vendor-prefixes.txt b/Documentation/devicetree/bindings/vendor-prefixes.txt
index 8033919..08490ef 100644
--- a/Documentation/devicetree/bindings/vendor-prefixes.txt
+++ b/Documentation/devicetree/bindings/vendor-prefixes.txt
@@ -76,6 +76,7 @@ everspin Everspin Technologies, Inc.
excito Excito
fcs Fairchild Semiconductor
firefly Firefly
+focaltech FocalTech Systems Co.,Ltd
fsl Freescale Semiconductor
GEFanuc GE Fanuc Intelligent Platforms Embedded Systems, Inc.
gef GE Fanuc Intelligent Platforms Embedded Systems, Inc.
diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index d7e74a1..7982b87 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -295,6 +295,20 @@ config TOUCHSCREEN_EGALAX
To compile this driver as a module, choose M here: the
module will be called egalax_ts.
+config TOUCHSCREEN_FT6236
+ tristate "FT6236 I2C touchscreen"
+ depends on I2C
+ depends on GPIOLIB
+ help
+ Say Y here to enable support for the I2C connected FT6x06 and
+ FT6x36 family of capacitive touchscreen drivers.
+
+ If unsure, say N.
+
+ To compile this driver as a module, choose M here: the
+ module will be called ft6236.
+
+
config TOUCHSCREEN_FUJITSU
tristate "Fujitsu serial touchscreen"
select SERIO
diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
index a1be09f..c867f82 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -36,6 +36,7 @@ obj-$(CONFIG_TOUCHSCREEN_EETI) += eeti_ts.o
obj-$(CONFIG_TOUCHSCREEN_ELAN) += elants_i2c.o
obj-$(CONFIG_TOUCHSCREEN_ELO) += elo.o
obj-$(CONFIG_TOUCHSCREEN_EGALAX) += egalax_ts.o
+obj-$(CONFIG_TOUCHSCREEN_FT6236) += ft6236.o
obj-$(CONFIG_TOUCHSCREEN_FUJITSU) += fujitsu_ts.o
obj-$(CONFIG_TOUCHSCREEN_GOODIX) += goodix.o
obj-$(CONFIG_TOUCHSCREEN_ILI210X) += ili210x.o
diff --git a/drivers/input/touchscreen/ft6236.c b/drivers/input/touchscreen/ft6236.c
new file mode 100644
index 0000000..e8cd9fc
--- /dev/null
+++ b/drivers/input/touchscreen/ft6236.c
@@ -0,0 +1,322 @@
+/*
+ * FocalTech FT6236 TouchScreen driver.
+ *
+ * Copyright (c) 2010 Focal tech Ltd.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/input.h>
+#include <linux/input/mt.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/property.h>
+
+#define FT6236_MAX_TOUCH_POINTS 2
+
+#define FT6236_REG_TH_GROUP 0x80
+#define FT6236_REG_PERIODACTIVE 0x88
+#define FT6236_REG_LIB_VER_H 0xa1
+#define FT6236_REG_LIB_VER_L 0xa2
+#define FT6236_REG_CIPHER 0xa3
+#define FT6236_REG_FIRMID 0xa6
+#define FT6236_REG_FOCALTECH_ID 0xa8
+#define FT6236_REG_RELEASE_CODE_ID 0xaf
+
+#define FT6236_EVENT_PRESS_DOWN 0
+#define FT6236_EVENT_LIFT_UP 1
+#define FT6236_EVENT_CONTACT 2
+#define FT6236_EVENT_NO_EVENT 3
+
+struct ft6236_data {
+ struct i2c_client *client;
+ struct input_dev *input;
+ struct gpio_desc *reset_gpio;
+ u32 max_x;
+ u32 max_y;
+ bool invert_x;
+ bool invert_y;
+ bool swap_xy;
+};
+
+/*
+ * This struct is a touchpoint as stored in hardware. Note that the id,
+ * as well as the event, are stored in the upper nybble of the hi byte.
+ */
+struct ft6236_touchpoint {
+ union {
+ u8 xhi;
+ u8 event;
+ };
+ u8 xlo;
+ union {
+ u8 yhi;
+ u8 id;
+ };
+ u8 ylo;
+ u8 weight;
+ u8 misc;
+} __packed;
+
+/* This packet represents the register map as read from offset 0 */
+struct ft6236_packet {
+ u8 dev_mode;
+ u8 gest_id;
+ u8 touches;
+ struct ft6236_touchpoint points[FT6236_MAX_TOUCH_POINTS];
+} __packed;
+
+static int ft6236_read(struct i2c_client *client, u8 reg, u8 len, void *data)
+{
+ int error;
+
+ error = i2c_smbus_read_i2c_block_data(client, reg, len, data);
+ if (error < 0)
+ return error;
+ if (error != len)
+ return -EIO;
+ return 0;
+}
+
+static irqreturn_t ft6236_interrupt(int irq, void *dev_id)
+{
+ struct ft6236_data *ft6236 = dev_id;
+ struct device *dev = &ft6236->client->dev;
+ struct input_dev *input = ft6236->input;
+ struct ft6236_packet buf;
+ u8 touches;
+ int i, error;
+
+ error = ft6236_read(ft6236->client, 0, sizeof(buf), &buf);
+ if (error) {
+ dev_err(dev, "read touchdata failed %d\n", error);
+ return IRQ_HANDLED;
+ }
+
+ touches = buf.touches & 0xf;
+ if (touches > FT6236_MAX_TOUCH_POINTS) {
+ dev_dbg(dev,
+ "%d touch points reported, only %d are supported\n",
+ touches, FT6236_MAX_TOUCH_POINTS);
+ touches = FT6236_MAX_TOUCH_POINTS;
+ }
+
+ for (i = 0; i < touches; i++) {
+ u16 x = ((buf.points[i].xhi & 0xf) << 8) | buf.points[i].xlo;
+ u16 y = ((buf.points[i].yhi & 0xf) << 8) | buf.points[i].ylo;
+ u8 event = buf.points[i].event >> 6;
+ u8 id = buf.points[i].id >> 4;
+ bool act = (event == FT6236_EVENT_PRESS_DOWN ||
+ event == FT6236_EVENT_CONTACT);
+
+ input_mt_slot(input, id);
+ input_mt_report_slot_state(input, MT_TOOL_FINGER, act);
+ if (!act)
+ continue;
+
+ if (ft6236->invert_x)
+ x = ft6236->max_x - x;
+
+ if (ft6236->invert_y)
+ y = ft6236->max_y - y;
+
+ if (ft6236->swap_xy) {
+ input_report_abs(input, ABS_MT_POSITION_X, y);
+ input_report_abs(input, ABS_MT_POSITION_Y, x);
+ } else {
+ input_report_abs(input, ABS_MT_POSITION_X, x);
+ input_report_abs(input, ABS_MT_POSITION_Y, y);
+ }
+ }
+
+ input_mt_sync_frame(input);
+ input_sync(input);
+
+ return IRQ_HANDLED;
+}
+
+static u8 ft6236_debug_read_byte(struct ft6236_data *ft6236, u8 reg)
+{
+ struct i2c_client *client = ft6236->client;
+ u8 val = 0;
+ int error;
+
+ error = ft6236_read(client, reg, 1, &val);
+ if (error)
+ dev_dbg(&client->dev, "error reading register 0x%02x\n", reg);
+ return val;
+}
+
+static void ft6236_debug_info(struct ft6236_data *ft6236)
+{
+ struct device *dev = &ft6236->client->dev;
+
+ dev_dbg(dev, "Touch threshold is %d\n",
+ ft6236_debug_read_byte(ft6236, FT6236_REG_TH_GROUP) * 4);
+ dev_dbg(dev, "Report rate is %dHz\n",
+ ft6236_debug_read_byte(ft6236, FT6236_REG_PERIODACTIVE) * 10);
+ dev_dbg(dev, "Firmware library version 0x%02x%02x\n",
+ ft6236_debug_read_byte(ft6236, FT6236_REG_LIB_VER_H),
+ ft6236_debug_read_byte(ft6236, FT6236_REG_LIB_VER_L));
+ dev_dbg(dev, "Firmware version 0x%02x\n",
+ ft6236_debug_read_byte(ft6236, FT6236_REG_FIRMID));
+ dev_dbg(dev, "Chip vendor ID 0x%02x\n",
+ ft6236_debug_read_byte(ft6236, FT6236_REG_CIPHER));
+ dev_dbg(dev, "CTPM vendor ID 0x%02x\n",
+ ft6236_debug_read_byte(ft6236, FT6236_REG_FOCALTECH_ID));
+ dev_dbg(dev, "Release code version 0x%02x\n",
+ ft6236_debug_read_byte(ft6236, FT6236_REG_RELEASE_CODE_ID));
+}
+
+static void ft6236_reset(struct ft6236_data *ft6236)
+{
+ if (!ft6236->reset_gpio)
+ return;
+
+ gpiod_set_value_cansleep(ft6236->reset_gpio, 1);
+ usleep_range(5000, 20000);
+ gpiod_set_value_cansleep(ft6236->reset_gpio, 0);
+ msleep(300);
+}
+
+static int ft6236_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct device *dev = &client->dev;
+ struct ft6236_data *ft6236;
+ struct input_dev *input;
+ u32 fuzz_x = 0, fuzz_y = 0;
+ u8 val;
+ int error;
+
+ if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
+ return -ENODEV;
+
+ if (!client->irq) {
+ dev_err(dev, "irq is missing\n");
+ return -EINVAL;
+ }
+
+ ft6236 = devm_kzalloc(dev, sizeof(*ft6236), GFP_KERNEL);
+ if (!ft6236)
+ return -ENOMEM;
+
+ ft6236->client = client;
+ ft6236->reset_gpio = devm_gpiod_get_optional(dev, "reset",
+ GPIOD_OUT_LOW);
+ if (IS_ERR(ft6236->reset_gpio)) {
+ error = PTR_ERR(ft6236->reset_gpio);
+ if (error != -EPROBE_DEFER)
+ dev_err(dev, "error getting reset gpio\n");
+ return error;
+ }
+
+ ft6236_reset(ft6236);
+
+ /* verify that the controller is present */
+ error = ft6236_read(client, 0x00, 1, &val);
+ if (error) {
+ dev_err(dev, "failed to read from controller\n");
+ return error;
+ }
+
+ ft6236_debug_info(ft6236);
+
+ input = devm_input_allocate_device(dev);
+ if (!input)
+ return -ENOMEM;
+
+ ft6236->input = input;
+ input->name = client->name;
+ input->id.bustype = BUS_I2C;
+
+ if (device_property_read_u32(dev, "touchscreen-size-x",
+ &ft6236->max_x) ||
+ device_property_read_u32(dev, "touchscreen-size-y",
+ &ft6236->max_y)) {
+ dev_err(dev, "touchscreen-size-x and/or -y missing\n");
+ return -EINVAL;
+ }
+
+ device_property_read_u32(dev, "touchscreen-fuzz-x", &fuzz_x);
+ device_property_read_u32(dev, "touchscreen-fuzz-y", &fuzz_y);
+ ft6236->invert_x = device_property_read_bool(dev,
+ "touchscreen-inverted-x");
+ ft6236->invert_y = device_property_read_bool(dev,
+ "touchscreen-inverted-y");
+ ft6236->swap_xy = device_property_read_bool(dev,
+ "touchscreen-swapped-x-y");
+
+ if (ft6236->swap_xy) {
+ input_set_abs_params(input, ABS_MT_POSITION_X, 0,
+ ft6236->max_y, fuzz_y, 0);
+ input_set_abs_params(input, ABS_MT_POSITION_Y, 0,
+ ft6236->max_x, fuzz_x, 0);
+ } else {
+ input_set_abs_params(input, ABS_MT_POSITION_X, 0,
+ ft6236->max_x, fuzz_x, 0);
+ input_set_abs_params(input, ABS_MT_POSITION_Y, 0,
+ ft6236->max_y, fuzz_y, 0);
+ }
+
+ error = input_mt_init_slots(input, FT6236_MAX_TOUCH_POINTS,
+ INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
+ if (error)
+ return error;
+
+ error = devm_request_threaded_irq(dev, client->irq, NULL,
+ ft6236_interrupt, IRQF_ONESHOT,
+ client->name, ft6236);
+ if (error < 0) {
+ dev_err(dev, "request irq failed\n");
+ return error;
+ }
+
+ error = input_register_device(input);
+ if (error) {
+ dev_err(dev, "failed to register input device\n");
+ return error;
+ }
+
+ return 0;
+}
+
+static const struct of_device_id ft6236_of_match[] = {
+ { .compatible = "focaltech,ft6236", },
+ { }
+};
+MODULE_DEVICE_TABLE(of, ft6236_of_match);
+
+static const struct i2c_device_id ft6236_id[] = {
+ { "ft6236", },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, ft6236_id);
+
+static struct i2c_driver ft6236_driver = {
+ .driver = {
+ .name = "ft6236",
+ .owner = THIS_MODULE,
+ .of_match_table = ft6236_of_match,
+ },
+ .probe = ft6236_probe,
+ .id_table = ft6236_id,
+};
+
+module_i2c_driver(ft6236_driver);
+
+MODULE_AUTHOR("Sean Cross <xobs@xxxxxxxxxx>");
+MODULE_AUTHOR("Noralf TrÃnnes <noralf@xxxxxxxxxxx>");
+MODULE_DESCRIPTION("FocalTech FT6236 TouchScreen driver");
+MODULE_LICENSE("GPL");
--
2.2.2
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