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 ST_TS_MAX_FINGERS 10 30 31 struct st_chip_info { 32 bool have_z; 33 u16 max_x; 34 u16 max_y; 35 u16 max_area; 36 u16 max_fingers; 37 u8 start_reg; 38 }; 39 40 struct st1232_ts_data { 41 struct i2c_client *client; 42 struct input_dev *input_dev; 43 struct touchscreen_properties prop; 44 struct dev_pm_qos_request low_latency_req; 45 struct gpio_desc *reset_gpio; 46 const struct st_chip_info *chip_info; 47 int read_buf_len; 48 u8 *read_buf; 49 }; 50 51 static int st1232_ts_read_data(struct st1232_ts_data *ts) 52 { 53 struct i2c_client *client = ts->client; 54 u8 start_reg = ts->chip_info->start_reg; 55 struct i2c_msg msg[] = { 56 { 57 .addr = client->addr, 58 .len = sizeof(start_reg), 59 .buf = &start_reg, 60 }, 61 { 62 .addr = client->addr, 63 .flags = I2C_M_RD | I2C_M_DMA_SAFE, 64 .len = ts->read_buf_len, 65 .buf = ts->read_buf, 66 } 67 }; 68 int ret; 69 70 ret = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg)); 71 if (ret != ARRAY_SIZE(msg)) 72 return ret < 0 ? ret : -EIO; 73 74 return 0; 75 } 76 77 static int st1232_ts_parse_and_report(struct st1232_ts_data *ts) 78 { 79 struct input_dev *input = ts->input_dev; 80 struct input_mt_pos pos[ST_TS_MAX_FINGERS]; 81 u8 z[ST_TS_MAX_FINGERS]; 82 int slots[ST_TS_MAX_FINGERS]; 83 int n_contacts = 0; 84 int i; 85 86 for (i = 0; i < ts->chip_info->max_fingers; i++) { 87 u8 *buf = &ts->read_buf[i * 4]; 88 89 if (buf[0] & BIT(7)) { 90 unsigned int x = ((buf[0] & 0x70) << 4) | buf[1]; 91 unsigned int y = ((buf[0] & 0x07) << 8) | buf[2]; 92 93 touchscreen_set_mt_pos(&pos[n_contacts], 94 &ts->prop, x, y); 95 96 /* st1232 includes a z-axis / touch strength */ 97 if (ts->chip_info->have_z) 98 z[n_contacts] = ts->read_buf[i + 6]; 99 100 n_contacts++; 101 } 102 } 103 104 input_mt_assign_slots(input, slots, pos, n_contacts, 0); 105 for (i = 0; i < n_contacts; i++) { 106 input_mt_slot(input, slots[i]); 107 input_mt_report_slot_state(input, MT_TOOL_FINGER, true); 108 input_report_abs(input, ABS_MT_POSITION_X, pos[i].x); 109 input_report_abs(input, ABS_MT_POSITION_Y, pos[i].y); 110 if (ts->chip_info->have_z) 111 input_report_abs(input, ABS_MT_TOUCH_MAJOR, z[i]); 112 } 113 114 input_mt_sync_frame(input); 115 input_sync(input); 116 117 return n_contacts; 118 } 119 120 static irqreturn_t st1232_ts_irq_handler(int irq, void *dev_id) 121 { 122 struct st1232_ts_data *ts = dev_id; 123 int count; 124 int error; 125 126 error = st1232_ts_read_data(ts); 127 if (error) 128 goto out; 129 130 count = st1232_ts_parse_and_report(ts); 131 if (!count) { 132 if (ts->low_latency_req.dev) { 133 dev_pm_qos_remove_request(&ts->low_latency_req); 134 ts->low_latency_req.dev = NULL; 135 } 136 } else if (!ts->low_latency_req.dev) { 137 /* First contact, request 100 us latency. */ 138 dev_pm_qos_add_ancestor_request(&ts->client->dev, 139 &ts->low_latency_req, 140 DEV_PM_QOS_RESUME_LATENCY, 100); 141 } 142 143 out: 144 return IRQ_HANDLED; 145 } 146 147 static void st1232_ts_power(struct st1232_ts_data *ts, bool poweron) 148 { 149 if (ts->reset_gpio) 150 gpiod_set_value_cansleep(ts->reset_gpio, !poweron); 151 } 152 153 static void st1232_ts_power_off(void *data) 154 { 155 st1232_ts_power(data, false); 156 } 157 158 static const struct st_chip_info st1232_chip_info = { 159 .have_z = true, 160 .max_x = 0x31f, /* 800 - 1 */ 161 .max_y = 0x1df, /* 480 -1 */ 162 .max_area = 0xff, 163 .max_fingers = 2, 164 .start_reg = 0x12, 165 }; 166 167 static const struct st_chip_info st1633_chip_info = { 168 .have_z = false, 169 .max_x = 0x13f, /* 320 - 1 */ 170 .max_y = 0x1df, /* 480 -1 */ 171 .max_area = 0x00, 172 .max_fingers = 5, 173 .start_reg = 0x12, 174 }; 175 176 static int st1232_ts_probe(struct i2c_client *client, 177 const struct i2c_device_id *id) 178 { 179 const struct st_chip_info *match; 180 struct st1232_ts_data *ts; 181 struct input_dev *input_dev; 182 int error; 183 184 match = device_get_match_data(&client->dev); 185 if (!match && id) 186 match = (const void *)id->driver_data; 187 if (!match) { 188 dev_err(&client->dev, "unknown device model\n"); 189 return -ENODEV; 190 } 191 192 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) { 193 dev_err(&client->dev, "need I2C_FUNC_I2C\n"); 194 return -EIO; 195 } 196 197 if (!client->irq) { 198 dev_err(&client->dev, "no IRQ?\n"); 199 return -EINVAL; 200 } 201 202 ts = devm_kzalloc(&client->dev, sizeof(*ts), GFP_KERNEL); 203 if (!ts) 204 return -ENOMEM; 205 206 ts->chip_info = match; 207 208 /* allocate a buffer according to the number of registers to read */ 209 ts->read_buf_len = ts->chip_info->max_fingers * 4; 210 ts->read_buf = devm_kzalloc(&client->dev, ts->read_buf_len, GFP_KERNEL); 211 if (!ts->read_buf) 212 return -ENOMEM; 213 214 input_dev = devm_input_allocate_device(&client->dev); 215 if (!input_dev) 216 return -ENOMEM; 217 218 ts->client = client; 219 ts->input_dev = input_dev; 220 221 ts->reset_gpio = devm_gpiod_get_optional(&client->dev, NULL, 222 GPIOD_OUT_HIGH); 223 if (IS_ERR(ts->reset_gpio)) { 224 error = PTR_ERR(ts->reset_gpio); 225 dev_err(&client->dev, "Unable to request GPIO pin: %d.\n", 226 error); 227 return error; 228 } 229 230 st1232_ts_power(ts, true); 231 232 error = devm_add_action_or_reset(&client->dev, st1232_ts_power_off, ts); 233 if (error) { 234 dev_err(&client->dev, 235 "Failed to install power off action: %d\n", error); 236 return error; 237 } 238 239 input_dev->name = "st1232-touchscreen"; 240 input_dev->id.bustype = BUS_I2C; 241 242 if (ts->chip_info->have_z) 243 input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR, 0, 244 ts->chip_info->max_area, 0, 0); 245 246 input_set_abs_params(input_dev, ABS_MT_POSITION_X, 247 0, ts->chip_info->max_x, 0, 0); 248 input_set_abs_params(input_dev, ABS_MT_POSITION_Y, 249 0, ts->chip_info->max_y, 0, 0); 250 251 touchscreen_parse_properties(input_dev, true, &ts->prop); 252 253 error = input_mt_init_slots(input_dev, ts->chip_info->max_fingers, 254 INPUT_MT_DIRECT | INPUT_MT_TRACK | 255 INPUT_MT_DROP_UNUSED); 256 if (error) { 257 dev_err(&client->dev, "failed to initialize MT slots\n"); 258 return error; 259 } 260 261 error = devm_request_threaded_irq(&client->dev, client->irq, 262 NULL, st1232_ts_irq_handler, 263 IRQF_ONESHOT, 264 client->name, ts); 265 if (error) { 266 dev_err(&client->dev, "Failed to register interrupt\n"); 267 return error; 268 } 269 270 error = input_register_device(ts->input_dev); 271 if (error) { 272 dev_err(&client->dev, "Unable to register %s input device\n", 273 input_dev->name); 274 return error; 275 } 276 277 i2c_set_clientdata(client, ts); 278 279 return 0; 280 } 281 282 static int __maybe_unused st1232_ts_suspend(struct device *dev) 283 { 284 struct i2c_client *client = to_i2c_client(dev); 285 struct st1232_ts_data *ts = i2c_get_clientdata(client); 286 287 disable_irq(client->irq); 288 289 if (!device_may_wakeup(&client->dev)) 290 st1232_ts_power(ts, false); 291 292 return 0; 293 } 294 295 static int __maybe_unused st1232_ts_resume(struct device *dev) 296 { 297 struct i2c_client *client = to_i2c_client(dev); 298 struct st1232_ts_data *ts = i2c_get_clientdata(client); 299 300 if (!device_may_wakeup(&client->dev)) 301 st1232_ts_power(ts, true); 302 303 enable_irq(client->irq); 304 305 return 0; 306 } 307 308 static SIMPLE_DEV_PM_OPS(st1232_ts_pm_ops, 309 st1232_ts_suspend, st1232_ts_resume); 310 311 static const struct i2c_device_id st1232_ts_id[] = { 312 { ST1232_TS_NAME, (unsigned long)&st1232_chip_info }, 313 { ST1633_TS_NAME, (unsigned long)&st1633_chip_info }, 314 { } 315 }; 316 MODULE_DEVICE_TABLE(i2c, st1232_ts_id); 317 318 static const struct of_device_id st1232_ts_dt_ids[] = { 319 { .compatible = "sitronix,st1232", .data = &st1232_chip_info }, 320 { .compatible = "sitronix,st1633", .data = &st1633_chip_info }, 321 { } 322 }; 323 MODULE_DEVICE_TABLE(of, st1232_ts_dt_ids); 324 325 static struct i2c_driver st1232_ts_driver = { 326 .probe = st1232_ts_probe, 327 .id_table = st1232_ts_id, 328 .driver = { 329 .name = ST1232_TS_NAME, 330 .of_match_table = st1232_ts_dt_ids, 331 .pm = &st1232_ts_pm_ops, 332 }, 333 }; 334 335 module_i2c_driver(st1232_ts_driver); 336 337 MODULE_AUTHOR("Tony SIM <chinyeow.sim.xt@renesas.com>"); 338 MODULE_AUTHOR("Martin Kepplinger <martin.kepplinger@ginzinger.com>"); 339 MODULE_DESCRIPTION("SITRONIX ST1232 Touchscreen Controller Driver"); 340 MODULE_LICENSE("GPL v2"); 341