/* * 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 #include #include #include #include #include #include #include #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", .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 "); MODULE_AUTHOR("Noralf Trønnes "); MODULE_DESCRIPTION("FocalTech FT6236 TouchScreen driver"); MODULE_LICENSE("GPL v2");