1 /* 2 * TSC-40 serial touchscreen driver. It should be compatible with 3 * TSC-10 and 25. 4 * 5 * Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de> 6 * License: GPLv2 as published by the FSF. 7 */ 8 9 #include <linux/kernel.h> 10 #include <linux/module.h> 11 #include <linux/slab.h> 12 #include <linux/input.h> 13 #include <linux/serio.h> 14 #include <linux/init.h> 15 16 #define PACKET_LENGTH 5 17 struct tsc_ser { 18 struct input_dev *dev; 19 struct serio *serio; 20 u32 idx; 21 unsigned char data[PACKET_LENGTH]; 22 char phys[32]; 23 }; 24 25 static void tsc_process_data(struct tsc_ser *ptsc) 26 { 27 struct input_dev *dev = ptsc->dev; 28 u8 *data = ptsc->data; 29 u32 x; 30 u32 y; 31 32 x = ((data[1] & 0x03) << 8) | data[2]; 33 y = ((data[3] & 0x03) << 8) | data[4]; 34 35 input_report_abs(dev, ABS_X, x); 36 input_report_abs(dev, ABS_Y, y); 37 input_report_key(dev, BTN_TOUCH, 1); 38 39 input_sync(dev); 40 } 41 42 static irqreturn_t tsc_interrupt(struct serio *serio, 43 unsigned char data, unsigned int flags) 44 { 45 struct tsc_ser *ptsc = serio_get_drvdata(serio); 46 struct input_dev *dev = ptsc->dev; 47 48 ptsc->data[ptsc->idx] = data; 49 switch (ptsc->idx++) { 50 case 0: 51 if (unlikely((data & 0x3e) != 0x10)) { 52 dev_dbg(&serio->dev, 53 "unsynchronized packet start (0x%02x)\n", data); 54 ptsc->idx = 0; 55 } else if (!(data & 0x01)) { 56 input_report_key(dev, BTN_TOUCH, 0); 57 input_sync(dev); 58 ptsc->idx = 0; 59 } 60 break; 61 62 case 1: 63 case 3: 64 if (unlikely(data & 0xfc)) { 65 dev_dbg(&serio->dev, 66 "unsynchronized data 0x%02x at offset %d\n", 67 data, ptsc->idx - 1); 68 ptsc->idx = 0; 69 } 70 break; 71 72 case 4: 73 tsc_process_data(ptsc); 74 ptsc->idx = 0; 75 break; 76 } 77 78 return IRQ_HANDLED; 79 } 80 81 static int tsc_connect(struct serio *serio, struct serio_driver *drv) 82 { 83 struct tsc_ser *ptsc; 84 struct input_dev *input_dev; 85 int error; 86 87 ptsc = kzalloc(sizeof(struct tsc_ser), GFP_KERNEL); 88 input_dev = input_allocate_device(); 89 if (!ptsc || !input_dev) { 90 error = -ENOMEM; 91 goto fail1; 92 } 93 94 ptsc->serio = serio; 95 ptsc->dev = input_dev; 96 snprintf(ptsc->phys, sizeof(ptsc->phys), "%s/input0", serio->phys); 97 98 input_dev->name = "TSC-10/25/40 Serial TouchScreen"; 99 input_dev->phys = ptsc->phys; 100 input_dev->id.bustype = BUS_RS232; 101 input_dev->id.vendor = SERIO_TSC40; 102 input_dev->id.product = 40; 103 input_dev->id.version = 0x0001; 104 input_dev->dev.parent = &serio->dev; 105 106 input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS); 107 __set_bit(BTN_TOUCH, input_dev->keybit); 108 input_set_abs_params(ptsc->dev, ABS_X, 0, 0x3ff, 0, 0); 109 input_set_abs_params(ptsc->dev, ABS_Y, 0, 0x3ff, 0, 0); 110 input_set_abs_params(ptsc->dev, ABS_PRESSURE, 0, 0, 0, 0); 111 112 serio_set_drvdata(serio, ptsc); 113 114 error = serio_open(serio, drv); 115 if (error) 116 goto fail2; 117 118 error = input_register_device(ptsc->dev); 119 if (error) 120 goto fail3; 121 122 return 0; 123 124 fail3: 125 serio_close(serio); 126 fail2: 127 serio_set_drvdata(serio, NULL); 128 fail1: 129 input_free_device(input_dev); 130 kfree(ptsc); 131 return error; 132 } 133 134 static void tsc_disconnect(struct serio *serio) 135 { 136 struct tsc_ser *ptsc = serio_get_drvdata(serio); 137 138 serio_close(serio); 139 140 input_unregister_device(ptsc->dev); 141 kfree(ptsc); 142 143 serio_set_drvdata(serio, NULL); 144 } 145 146 static struct serio_device_id tsc_serio_ids[] = { 147 { 148 .type = SERIO_RS232, 149 .proto = SERIO_TSC40, 150 .id = SERIO_ANY, 151 .extra = SERIO_ANY, 152 }, 153 { 0 } 154 }; 155 MODULE_DEVICE_TABLE(serio, tsc_serio_ids); 156 157 #define DRIVER_DESC "TSC-10/25/40 serial touchscreen driver" 158 159 static struct serio_driver tsc_drv = { 160 .driver = { 161 .name = "tsc40", 162 }, 163 .description = DRIVER_DESC, 164 .id_table = tsc_serio_ids, 165 .interrupt = tsc_interrupt, 166 .connect = tsc_connect, 167 .disconnect = tsc_disconnect, 168 }; 169 170 static int __init tsc_ser_init(void) 171 { 172 return serio_register_driver(&tsc_drv); 173 } 174 module_init(tsc_ser_init); 175 176 static void __exit tsc_exit(void) 177 { 178 serio_unregister_driver(&tsc_drv); 179 } 180 module_exit(tsc_exit); 181 182 MODULE_AUTHOR("Sebastian Andrzej Siewior <bigeasy@linutronix.de>"); 183 MODULE_DESCRIPTION(DRIVER_DESC); 184 MODULE_LICENSE("GPL v2"); 185