--- /dev/null
+/*
+ * 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++) {
+ struct ft6236_touchpoint *point = &buf.points[i];
+ u16 x = ((point->xhi & 0xf) << 8) | buf.points[i].xlo;
+ u16 y = ((point->yhi & 0xf) << 8) | buf.points[i].ylo;
+ u8 event = point->event >> 6;
+ u8 id = point->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: %d\n", reg, error);
+
+ 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 -ENXIO;
+
+ 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: %d\n", error);
+ 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: %d\n", error);
+ 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) {
+ dev_err(dev, "request irq %d failed: %d\n", client->irq, error);
+ return error;
+ }
+
+ error = input_register_device(input);
+ if (error) {
+ dev_err(dev, "failed to register input device: %d\n", error);
+ return error;
+ }
+
+ return 0;
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id ft6236_of_match[] = {
+ { .compatible = "focaltech,ft6236", },
+ { }
+};
+MODULE_DEVICE_TABLE(of, ft6236_of_match);
+#endif
+
+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 = of_match_ptr(ft6236_of_match),
+ },
+ .probe = ft6236_probe,
+ .id_table = ft6236_id,
+};
+module_i2c_driver(ft6236_driver);
+
+MODULE_AUTHOR("Sean Cross <xobs@kosagi.com>");
+MODULE_AUTHOR("Noralf Trønnes <noralf@tronnes.org>");
+MODULE_DESCRIPTION("FocalTech FT6236 TouchScreen driver");
+MODULE_LICENSE("GPL");
projects / karo-tx-linux.git / commitdiff