1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * ST1232 Touchscreen Controller Driver 4 * 5 * Copyright (C) 2010 Renesas Solutions Corp. 6 * Tony SIM <chinyeow.sim.xt@renesas.com> 7 * 8 * Using code from: 9 * - android.git.kernel.org: projects/kernel/common.git: synaptics_i2c_rmi.c 10 * Copyright (C) 2007 Google, Inc. 11 */ 12 13 #include <linux/delay.h> 14 #include <linux/gpio/consumer.h> 15 #include <linux/i2c.h> 16 #include <linux/input.h> 17 #include <linux/input/mt.h> 18 #include <linux/input/touchscreen.h> 19 #include <linux/interrupt.h> 20 #include <linux/module.h> 21 #include <linux/of.h> 22 #include <linux/pm_qos.h> 23 #include <linux/slab.h> 24 #include <linux/types.h> 25 26 #define ST1232_TS_NAME "st1232-ts" 27 #define ST1633_TS_NAME "st1633-ts" 28 29 #define REG_XY_RESOLUTION 0x04 30 #define REG_XY_COORDINATES 0x12 31 #define ST_TS_MAX_FINGERS 10 32 33 struct st_chip_info { 34 bool have_z; 35 u16 max_area; 36 u16 max_fingers; 37 }; 38 39 struct st1232_ts_data { 40 struct i2c_client *client; 41 struct input_dev *input_dev; 42 struct touchscreen_properties prop; 43 struct dev_pm_qos_request low_latency_req; 44 struct gpio_desc *reset_gpio; 45 const struct st_chip_info *chip_info; 46 int read_buf_len; 47 u8 *read_buf; 48 }; 49 50 static int st1232_ts_read_data(struct st1232_ts_data *ts, u8 reg) 51 { 52 struct i2c_client *client = ts->client; 53 struct i2c_msg msg[] = { 54 { 55 .addr = client->addr, 56 .len = sizeof(reg), 57 .buf = ®, 58 }, 59 { 60 .addr = client->addr, 61 .flags = I2C_M_RD | I2C_M_DMA_SAFE, 62 .len = ts->read_buf_len, 63 .buf = ts->read_buf, 64 } 65 }; 66 int ret; 67 68 ret = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg)); 69 if (ret != ARRAY_SIZE(msg)) 70 return ret < 0 ? ret : -EIO; 71 72 return 0; 73 } 74 75 static int st1232_ts_read_resolution(struct st1232_ts_data *ts, u16 *max_x, 76 u16 *max_y) 77 { 78 u8 *buf; 79 int error; 80 81 /* select resolution register */ 82 error = st1232_ts_read_data(ts, REG_XY_RESOLUTION); 83 if (error) 84 return error; 85 86 buf = ts->read_buf; 87 88 *max_x = ((buf[0] & 0x0070) << 4) | buf[1]; 89 *max_y = ((buf[0] & 0x0007) << 8) | buf[2]; 90 91 return 0; 92 } 93 94 static int st1232_ts_parse_and_report(struct st1232_ts_data *ts) 95 { 96 struct input_dev *input = ts->input_dev; 97 struct input_mt_pos pos[ST_TS_MAX_FINGERS]; 98 u8 z[ST_TS_MAX_FINGERS]; 99 int slots[ST_TS_MAX_FINGERS]; 100 int n_contacts = 0; 101 int i; 102 103 for (i = 0; i < ts->chip_info->max_fingers; i++) { 104 u8 *buf = &ts->read_buf[i * 4]; 105 106 if (buf[0] & BIT(7)) { 107 unsigned int x = ((buf[0] & 0x70) << 4) | buf[1]; 108 unsigned int y = ((buf[0] & 0x07) << 8) | buf[2]; 109 110 touchscreen_set_mt_pos(&pos[n_contacts], 111 &ts->prop, x, y); 112 113 /* st1232 includes a z-axis / touch strength */ 114 if (ts->chip_info->have_z) 115 z[n_contacts] = ts->read_buf[i + 6]; 116 117 n_contacts++; 118 } 119 } 120 121 input_mt_assign_slots(input, slots, pos, n_contacts, 0); 122 for (i = 0; i < n_contacts; i++) { 123 input_mt_slot(input, slots[i]); 124 input_mt_report_slot_state(input, MT_TOOL_FINGER, true); 125 input_report_abs(input, ABS_MT_POSITION_X, pos[i].x); 126 input_report_abs(input, ABS_MT_POSITION_Y, pos[i].y); 127 if (ts->chip_info->have_z) 128 input_report_abs(input, ABS_MT_TOUCH_MAJOR, z[i]); 129 } 130 131 input_mt_sync_frame(input); 132 input_sync(input); 133 134 return n_contacts; 135 } 136 137 static irqreturn_t st1232_ts_irq_handler(int irq, void *dev_id) 138 { 139 struct st1232_ts_data *ts = dev_id; 140 int count; 141 int error; 142 143 error = st1232_ts_read_data(ts, REG_XY_COORDINATES); 144 if (error) 145 goto out; 146 147 count = st1232_ts_parse_and_report(ts); 148 if (!count) { 149 if (ts->low_latency_req.dev) { 150 dev_pm_qos_remove_request(&ts->low_latency_req); 151 ts->low_latency_req.dev = NULL; 152 } 153 } else if (!ts->low_latency_req.dev) { 154 /* First contact, request 100 us latency. */ 155 dev_pm_qos_add_ancestor_request(&ts->client->dev, 156 &ts->low_latency_req, 157 DEV_PM_QOS_RESUME_LATENCY, 100); 158 } 159 160 out: 161 return IRQ_HANDLED; 162 } 163 164 static void st1232_ts_power(struct st1232_ts_data *ts, bool poweron) 165 { 166 if (ts->reset_gpio) 167 gpiod_set_value_cansleep(ts->reset_gpio, !poweron); 168 } 169 170 static void st1232_ts_power_off(void *data) 171 { 172 st1232_ts_power(data, false); 173 } 174 175 static const struct st_chip_info st1232_chip_info = { 176 .have_z = true, 177 .max_area = 0xff, 178 .max_fingers = 2, 179 }; 180 181 static const struct st_chip_info st1633_chip_info = { 182 .have_z = false, 183 .max_area = 0x00, 184 .max_fingers = 5, 185 }; 186 187 static int st1232_ts_probe(struct i2c_client *client, 188 const struct i2c_device_id *id) 189 { 190 const struct st_chip_info *match; 191 struct st1232_ts_data *ts; 192 struct input_dev *input_dev; 193 u16 max_x, max_y; 194 int error; 195 196 match = device_get_match_data(&client->dev); 197 if (!match && id) 198 match = (const void *)id->driver_data; 199 if (!match) { 200 dev_err(&client->dev, "unknown device model\n"); 201 return -ENODEV; 202 } 203 204 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) { 205 dev_err(&client->dev, "need I2C_FUNC_I2C\n"); 206 return -EIO; 207 } 208 209 if (!client->irq) { 210 dev_err(&client->dev, "no IRQ?\n"); 211 return -EINVAL; 212 } 213 214 ts = devm_kzalloc(&client->dev, sizeof(*ts), GFP_KERNEL); 215 if (!ts) 216 return -ENOMEM; 217 218 ts->chip_info = match; 219 220 /* allocate a buffer according to the number of registers to read */ 221 ts->read_buf_len = ts->chip_info->max_fingers * 4; 222 ts->read_buf = devm_kzalloc(&client->dev, ts->read_buf_len, GFP_KERNEL); 223 if (!ts->read_buf) 224 return -ENOMEM; 225 226 input_dev = devm_input_allocate_device(&client->dev); 227 if (!input_dev) 228 return -ENOMEM; 229 230 ts->client = client; 231 ts->input_dev = input_dev; 232 233 ts->reset_gpio = devm_gpiod_get_optional(&client->dev, NULL, 234 GPIOD_OUT_HIGH); 235 if (IS_ERR(ts->reset_gpio)) { 236 error = PTR_ERR(ts->reset_gpio); 237 dev_err(&client->dev, "Unable to request GPIO pin: %d.\n", 238 error); 239 return error; 240 } 241 242 st1232_ts_power(ts, true); 243 244 error = devm_add_action_or_reset(&client->dev, st1232_ts_power_off, ts); 245 if (error) { 246 dev_err(&client->dev, 247 "Failed to install power off action: %d\n", error); 248 return error; 249 } 250 251 input_dev->name = "st1232-touchscreen"; 252 input_dev->id.bustype = BUS_I2C; 253 254 /* Read resolution from the chip */ 255 error = st1232_ts_read_resolution(ts, &max_x, &max_y); 256 if (error) { 257 dev_err(&client->dev, 258 "Failed to read resolution: %d\n", error); 259 return error; 260 } 261 262 if (ts->chip_info->have_z) 263 input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR, 0, 264 ts->chip_info->max_area, 0, 0); 265 266 input_set_abs_params(input_dev, ABS_MT_POSITION_X, 267 0, max_x, 0, 0); 268 input_set_abs_params(input_dev, ABS_MT_POSITION_Y, 269 0, max_y, 0, 0); 270 271 touchscreen_parse_properties(input_dev, true, &ts->prop); 272 273 error = input_mt_init_slots(input_dev, ts->chip_info->max_fingers, 274 INPUT_MT_DIRECT | INPUT_MT_TRACK | 275 INPUT_MT_DROP_UNUSED); 276 if (error) { 277 dev_err(&client->dev, "failed to initialize MT slots\n"); 278 return error; 279 } 280 281 error = devm_request_threaded_irq(&client->dev, client->irq, 282 NULL, st1232_ts_irq_handler, 283 IRQF_ONESHOT, 284 client->name, ts); 285 if (error) { 286 dev_err(&client->dev, "Failed to register interrupt\n"); 287 return error; 288 } 289 290 error = input_register_device(ts->input_dev); 291 if (error) { 292 dev_err(&client->dev, "Unable to register %s input device\n", 293 input_dev->name); 294 return error; 295 } 296 297 i2c_set_clientdata(client, ts); 298 299 return 0; 300 } 301 302 static int __maybe_unused st1232_ts_suspend(struct device *dev) 303 { 304 struct i2c_client *client = to_i2c_client(dev); 305 struct st1232_ts_data *ts = i2c_get_clientdata(client); 306 307 disable_irq(client->irq); 308 309 if (!device_may_wakeup(&client->dev)) 310 st1232_ts_power(ts, false); 311 312 return 0; 313 } 314 315 static int __maybe_unused st1232_ts_resume(struct device *dev) 316 { 317 struct i2c_client *client = to_i2c_client(dev); 318 struct st1232_ts_data *ts = i2c_get_clientdata(client); 319 320 if (!device_may_wakeup(&client->dev)) 321 st1232_ts_power(ts, true); 322 323 enable_irq(client->irq); 324 325 return 0; 326 } 327 328 static SIMPLE_DEV_PM_OPS(st1232_ts_pm_ops, 329 st1232_ts_suspend, st1232_ts_resume); 330 331 static const struct i2c_device_id st1232_ts_id[] = { 332 { ST1232_TS_NAME, (unsigned long)&st1232_chip_info }, 333 { ST1633_TS_NAME, (unsigned long)&st1633_chip_info }, 334 { } 335 }; 336 MODULE_DEVICE_TABLE(i2c, st1232_ts_id); 337 338 static const struct of_device_id st1232_ts_dt_ids[] = { 339 { .compatible = "sitronix,st1232", .data = &st1232_chip_info }, 340 { .compatible = "sitronix,st1633", .data = &st1633_chip_info }, 341 { } 342 }; 343 MODULE_DEVICE_TABLE(of, st1232_ts_dt_ids); 344 345 static struct i2c_driver st1232_ts_driver = { 346 .probe = st1232_ts_probe, 347 .id_table = st1232_ts_id, 348 .driver = { 349 .name = ST1232_TS_NAME, 350 .of_match_table = st1232_ts_dt_ids, 351 .pm = &st1232_ts_pm_ops, 352 }, 353 }; 354 355 module_i2c_driver(st1232_ts_driver); 356 357 MODULE_AUTHOR("Tony SIM <chinyeow.sim.xt@renesas.com>"); 358 MODULE_AUTHOR("Martin Kepplinger <martin.kepplinger@ginzinger.com>"); 359 MODULE_DESCRIPTION("SITRONIX ST1232 Touchscreen Controller Driver"); 360 MODULE_LICENSE("GPL v2"); 361