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