1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Driver for cypress touch screen controller 4 * 5 * Copyright (c) 2009 Aava Mobile 6 * 7 * Some cleanups by Alan Cox <alan@linux.intel.com> 8 */ 9 10 #include <linux/i2c.h> 11 #include <linux/input.h> 12 #include <linux/interrupt.h> 13 #include <linux/gpio/consumer.h> 14 #include <linux/kernel.h> 15 #include <linux/module.h> 16 #include <linux/slab.h> 17 #include <asm/byteorder.h> 18 19 #define CY8CTMG110_DRIVER_NAME "cy8ctmg110" 20 21 /* Touch coordinates */ 22 #define CY8CTMG110_X_MIN 0 23 #define CY8CTMG110_Y_MIN 0 24 #define CY8CTMG110_X_MAX 759 25 #define CY8CTMG110_Y_MAX 465 26 27 28 /* cy8ctmg110 register definitions */ 29 #define CY8CTMG110_TOUCH_WAKEUP_TIME 0 30 #define CY8CTMG110_TOUCH_SLEEP_TIME 2 31 #define CY8CTMG110_TOUCH_X1 3 32 #define CY8CTMG110_TOUCH_Y1 5 33 #define CY8CTMG110_TOUCH_X2 7 34 #define CY8CTMG110_TOUCH_Y2 9 35 #define CY8CTMG110_FINGERS 11 36 #define CY8CTMG110_GESTURE 12 37 #define CY8CTMG110_REG_MAX 13 38 39 40 /* 41 * The touch driver structure. 42 */ 43 struct cy8ctmg110 { 44 struct input_dev *input; 45 char phys[32]; 46 struct i2c_client *client; 47 struct gpio_desc *reset_gpio; 48 }; 49 50 /* 51 * cy8ctmg110_power is the routine that is called when touch hardware 52 * is being powered off or on. When powering on this routine de-asserts 53 * the RESET line, when powering off reset line is asserted. 54 */ 55 static void cy8ctmg110_power(struct cy8ctmg110 *ts, bool poweron) 56 { 57 if (ts->reset_gpio) 58 gpiod_set_value_cansleep(ts->reset_gpio, !poweron); 59 } 60 61 static int cy8ctmg110_write_regs(struct cy8ctmg110 *tsc, unsigned char reg, 62 unsigned char len, unsigned char *value) 63 { 64 struct i2c_client *client = tsc->client; 65 int ret; 66 unsigned char i2c_data[6]; 67 68 BUG_ON(len > 5); 69 70 i2c_data[0] = reg; 71 memcpy(i2c_data + 1, value, len); 72 73 ret = i2c_master_send(client, i2c_data, len + 1); 74 if (ret != len + 1) { 75 dev_err(&client->dev, "i2c write data cmd failed\n"); 76 return ret < 0 ? ret : -EIO; 77 } 78 79 return 0; 80 } 81 82 static int cy8ctmg110_read_regs(struct cy8ctmg110 *tsc, 83 unsigned char *data, unsigned char len, unsigned char cmd) 84 { 85 struct i2c_client *client = tsc->client; 86 int ret; 87 struct i2c_msg msg[2] = { 88 /* first write slave position to i2c devices */ 89 { 90 .addr = client->addr, 91 .len = 1, 92 .buf = &cmd 93 }, 94 /* Second read data from position */ 95 { 96 .addr = client->addr, 97 .flags = I2C_M_RD, 98 .len = len, 99 .buf = data 100 } 101 }; 102 103 ret = i2c_transfer(client->adapter, msg, 2); 104 if (ret < 0) 105 return ret; 106 107 return 0; 108 } 109 110 static int cy8ctmg110_touch_pos(struct cy8ctmg110 *tsc) 111 { 112 struct input_dev *input = tsc->input; 113 unsigned char reg_p[CY8CTMG110_REG_MAX]; 114 115 memset(reg_p, 0, CY8CTMG110_REG_MAX); 116 117 /* Reading coordinates */ 118 if (cy8ctmg110_read_regs(tsc, reg_p, 9, CY8CTMG110_TOUCH_X1) != 0) 119 return -EIO; 120 121 /* Number of touch */ 122 if (reg_p[8] == 0) { 123 input_report_key(input, BTN_TOUCH, 0); 124 } else { 125 input_report_key(input, BTN_TOUCH, 1); 126 input_report_abs(input, ABS_X, 127 be16_to_cpup((__be16 *)(reg_p + 0))); 128 input_report_abs(input, ABS_Y, 129 be16_to_cpup((__be16 *)(reg_p + 2))); 130 } 131 132 input_sync(input); 133 134 return 0; 135 } 136 137 static int cy8ctmg110_set_sleepmode(struct cy8ctmg110 *ts, bool sleep) 138 { 139 unsigned char reg_p[3]; 140 141 if (sleep) { 142 reg_p[0] = 0x00; 143 reg_p[1] = 0xff; 144 reg_p[2] = 5; 145 } else { 146 reg_p[0] = 0x10; 147 reg_p[1] = 0xff; 148 reg_p[2] = 0; 149 } 150 151 return cy8ctmg110_write_regs(ts, CY8CTMG110_TOUCH_WAKEUP_TIME, 3, reg_p); 152 } 153 154 static irqreturn_t cy8ctmg110_irq_thread(int irq, void *dev_id) 155 { 156 struct cy8ctmg110 *tsc = dev_id; 157 158 cy8ctmg110_touch_pos(tsc); 159 160 return IRQ_HANDLED; 161 } 162 163 static void cy8ctmg110_shut_off(void *_ts) 164 { 165 struct cy8ctmg110 *ts = _ts; 166 167 cy8ctmg110_set_sleepmode(ts, true); 168 cy8ctmg110_power(ts, false); 169 } 170 171 static int cy8ctmg110_probe(struct i2c_client *client) 172 { 173 struct cy8ctmg110 *ts; 174 struct input_dev *input_dev; 175 int err; 176 177 if (!i2c_check_functionality(client->adapter, 178 I2C_FUNC_SMBUS_READ_WORD_DATA)) 179 return -EIO; 180 181 ts = devm_kzalloc(&client->dev, sizeof(*ts), GFP_KERNEL); 182 if (!ts) 183 return -ENOMEM; 184 185 input_dev = devm_input_allocate_device(&client->dev); 186 if (!input_dev) 187 return -ENOMEM; 188 189 ts->client = client; 190 ts->input = input_dev; 191 192 snprintf(ts->phys, sizeof(ts->phys), 193 "%s/input0", dev_name(&client->dev)); 194 195 input_dev->name = CY8CTMG110_DRIVER_NAME " Touchscreen"; 196 input_dev->phys = ts->phys; 197 input_dev->id.bustype = BUS_I2C; 198 199 input_set_capability(input_dev, EV_KEY, BTN_TOUCH); 200 input_set_abs_params(input_dev, ABS_X, 201 CY8CTMG110_X_MIN, CY8CTMG110_X_MAX, 4, 0); 202 input_set_abs_params(input_dev, ABS_Y, 203 CY8CTMG110_Y_MIN, CY8CTMG110_Y_MAX, 4, 0); 204 205 /* Request and assert reset line */ 206 ts->reset_gpio = devm_gpiod_get_optional(&client->dev, NULL, 207 GPIOD_OUT_HIGH); 208 if (IS_ERR(ts->reset_gpio)) { 209 err = PTR_ERR(ts->reset_gpio); 210 dev_err(&client->dev, 211 "Unable to request reset GPIO: %d\n", err); 212 return err; 213 } 214 215 cy8ctmg110_power(ts, true); 216 cy8ctmg110_set_sleepmode(ts, false); 217 218 err = devm_add_action_or_reset(&client->dev, cy8ctmg110_shut_off, ts); 219 if (err) 220 return err; 221 222 err = devm_request_threaded_irq(&client->dev, client->irq, 223 NULL, cy8ctmg110_irq_thread, 224 IRQF_ONESHOT, "touch_reset_key", ts); 225 if (err) { 226 dev_err(&client->dev, 227 "irq %d busy? error %d\n", client->irq, err); 228 return err; 229 } 230 231 err = input_register_device(input_dev); 232 if (err) 233 return err; 234 235 i2c_set_clientdata(client, ts); 236 237 return 0; 238 } 239 240 static int cy8ctmg110_suspend(struct device *dev) 241 { 242 struct i2c_client *client = to_i2c_client(dev); 243 struct cy8ctmg110 *ts = i2c_get_clientdata(client); 244 245 if (!device_may_wakeup(&client->dev)) { 246 cy8ctmg110_set_sleepmode(ts, true); 247 cy8ctmg110_power(ts, false); 248 } 249 250 return 0; 251 } 252 253 static int cy8ctmg110_resume(struct device *dev) 254 { 255 struct i2c_client *client = to_i2c_client(dev); 256 struct cy8ctmg110 *ts = i2c_get_clientdata(client); 257 258 if (!device_may_wakeup(&client->dev)) { 259 cy8ctmg110_power(ts, true); 260 cy8ctmg110_set_sleepmode(ts, false); 261 } 262 263 return 0; 264 } 265 266 static DEFINE_SIMPLE_DEV_PM_OPS(cy8ctmg110_pm, 267 cy8ctmg110_suspend, cy8ctmg110_resume); 268 269 static const struct i2c_device_id cy8ctmg110_idtable[] = { 270 { CY8CTMG110_DRIVER_NAME, 1 }, 271 { } 272 }; 273 274 MODULE_DEVICE_TABLE(i2c, cy8ctmg110_idtable); 275 276 static struct i2c_driver cy8ctmg110_driver = { 277 .driver = { 278 .name = CY8CTMG110_DRIVER_NAME, 279 .pm = pm_sleep_ptr(&cy8ctmg110_pm), 280 }, 281 .id_table = cy8ctmg110_idtable, 282 .probe = cy8ctmg110_probe, 283 }; 284 285 module_i2c_driver(cy8ctmg110_driver); 286 287 MODULE_AUTHOR("Samuli Konttila <samuli.konttila@aavamobile.com>"); 288 MODULE_DESCRIPTION("cy8ctmg110 TouchScreen Driver"); 289 MODULE_LICENSE("GPL v2"); 290