1 /*
2  * ST1232 Touchscreen Controller Driver
3  *
4  * Copyright (C) 2010 Renesas Solutions Corp.
5  *	Tony SIM <chinyeow.sim.xt@renesas.com>
6  *
7  * Using code from:
8  *  - android.git.kernel.org: projects/kernel/common.git: synaptics_i2c_rmi.c
9  *	Copyright (C) 2007 Google, Inc.
10  *
11  * This software is licensed under the terms of the GNU General Public
12  * License version 2, as published by the Free Software Foundation, and
13  * may be copied, distributed, and modified under those terms.
14  *
15  * This program is distributed in the hope that it will be useful,
16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18  * GNU General Public License for more details.
19  */
20 
21 #include <linux/delay.h>
22 #include <linux/gpio.h>
23 #include <linux/i2c.h>
24 #include <linux/input.h>
25 #include <linux/interrupt.h>
26 #include <linux/module.h>
27 #include <linux/of_gpio.h>
28 #include <linux/pm_qos.h>
29 #include <linux/slab.h>
30 #include <linux/types.h>
31 #include <linux/platform_data/st1232_pdata.h>
32 
33 #define ST1232_TS_NAME	"st1232-ts"
34 
35 #define MIN_X		0x00
36 #define MIN_Y		0x00
37 #define MAX_X		0x31f	/* (800 - 1) */
38 #define MAX_Y		0x1df	/* (480 - 1) */
39 #define MAX_AREA	0xff
40 #define MAX_FINGERS	2
41 
42 struct st1232_ts_finger {
43 	u16 x;
44 	u16 y;
45 	u8 t;
46 	bool is_valid;
47 };
48 
49 struct st1232_ts_data {
50 	struct i2c_client *client;
51 	struct input_dev *input_dev;
52 	struct st1232_ts_finger finger[MAX_FINGERS];
53 	struct dev_pm_qos_request low_latency_req;
54 	int reset_gpio;
55 };
56 
57 static int st1232_ts_read_data(struct st1232_ts_data *ts)
58 {
59 	struct st1232_ts_finger *finger = ts->finger;
60 	struct i2c_client *client = ts->client;
61 	struct i2c_msg msg[2];
62 	int error;
63 	u8 start_reg;
64 	u8 buf[10];
65 
66 	/* read touchscreen data from ST1232 */
67 	msg[0].addr = client->addr;
68 	msg[0].flags = 0;
69 	msg[0].len = 1;
70 	msg[0].buf = &start_reg;
71 	start_reg = 0x10;
72 
73 	msg[1].addr = ts->client->addr;
74 	msg[1].flags = I2C_M_RD;
75 	msg[1].len = sizeof(buf);
76 	msg[1].buf = buf;
77 
78 	error = i2c_transfer(client->adapter, msg, 2);
79 	if (error < 0)
80 		return error;
81 
82 	/* get "valid" bits */
83 	finger[0].is_valid = buf[2] >> 7;
84 	finger[1].is_valid = buf[5] >> 7;
85 
86 	/* get xy coordinate */
87 	if (finger[0].is_valid) {
88 		finger[0].x = ((buf[2] & 0x0070) << 4) | buf[3];
89 		finger[0].y = ((buf[2] & 0x0007) << 8) | buf[4];
90 		finger[0].t = buf[8];
91 	}
92 
93 	if (finger[1].is_valid) {
94 		finger[1].x = ((buf[5] & 0x0070) << 4) | buf[6];
95 		finger[1].y = ((buf[5] & 0x0007) << 8) | buf[7];
96 		finger[1].t = buf[9];
97 	}
98 
99 	return 0;
100 }
101 
102 static irqreturn_t st1232_ts_irq_handler(int irq, void *dev_id)
103 {
104 	struct st1232_ts_data *ts = dev_id;
105 	struct st1232_ts_finger *finger = ts->finger;
106 	struct input_dev *input_dev = ts->input_dev;
107 	int count = 0;
108 	int i, ret;
109 
110 	ret = st1232_ts_read_data(ts);
111 	if (ret < 0)
112 		goto end;
113 
114 	/* multi touch protocol */
115 	for (i = 0; i < MAX_FINGERS; i++) {
116 		if (!finger[i].is_valid)
117 			continue;
118 
119 		input_report_abs(input_dev, ABS_MT_TOUCH_MAJOR, finger[i].t);
120 		input_report_abs(input_dev, ABS_MT_POSITION_X, finger[i].x);
121 		input_report_abs(input_dev, ABS_MT_POSITION_Y, finger[i].y);
122 		input_mt_sync(input_dev);
123 		count++;
124 	}
125 
126 	/* SYN_MT_REPORT only if no contact */
127 	if (!count) {
128 		input_mt_sync(input_dev);
129 		if (ts->low_latency_req.dev) {
130 			dev_pm_qos_remove_request(&ts->low_latency_req);
131 			ts->low_latency_req.dev = NULL;
132 		}
133 	} else if (!ts->low_latency_req.dev) {
134 		/* First contact, request 100 us latency. */
135 		dev_pm_qos_add_ancestor_request(&ts->client->dev,
136 						&ts->low_latency_req, 100);
137 	}
138 
139 	/* SYN_REPORT */
140 	input_sync(input_dev);
141 
142 end:
143 	return IRQ_HANDLED;
144 }
145 
146 static void st1232_ts_power(struct st1232_ts_data *ts, bool poweron)
147 {
148 	if (gpio_is_valid(ts->reset_gpio))
149 		gpio_direction_output(ts->reset_gpio, poweron);
150 }
151 
152 static int st1232_ts_probe(struct i2c_client *client,
153 					const struct i2c_device_id *id)
154 {
155 	struct st1232_ts_data *ts;
156 	struct st1232_pdata *pdata = client->dev.platform_data;
157 	struct input_dev *input_dev;
158 	int error;
159 
160 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
161 		dev_err(&client->dev, "need I2C_FUNC_I2C\n");
162 		return -EIO;
163 	}
164 
165 	if (!client->irq) {
166 		dev_err(&client->dev, "no IRQ?\n");
167 		return -EINVAL;
168 	}
169 
170 	ts = devm_kzalloc(&client->dev, sizeof(*ts), GFP_KERNEL);
171 	if (!ts)
172 		return -ENOMEM;
173 
174 	input_dev = devm_input_allocate_device(&client->dev);
175 	if (!input_dev)
176 		return -ENOMEM;
177 
178 	ts->client = client;
179 	ts->input_dev = input_dev;
180 
181 	if (pdata)
182 		ts->reset_gpio = pdata->reset_gpio;
183 	else if (client->dev.of_node)
184 		ts->reset_gpio = of_get_gpio(client->dev.of_node, 0);
185 	else
186 		ts->reset_gpio = -ENODEV;
187 
188 	if (gpio_is_valid(ts->reset_gpio)) {
189 		error = devm_gpio_request(&client->dev, ts->reset_gpio, NULL);
190 		if (error) {
191 			dev_err(&client->dev,
192 				"Unable to request GPIO pin %d.\n",
193 				ts->reset_gpio);
194 				return error;
195 		}
196 	}
197 
198 	st1232_ts_power(ts, true);
199 
200 	input_dev->name = "st1232-touchscreen";
201 	input_dev->id.bustype = BUS_I2C;
202 	input_dev->dev.parent = &client->dev;
203 
204 	__set_bit(EV_SYN, input_dev->evbit);
205 	__set_bit(EV_KEY, input_dev->evbit);
206 	__set_bit(EV_ABS, input_dev->evbit);
207 
208 	input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR, 0, MAX_AREA, 0, 0);
209 	input_set_abs_params(input_dev, ABS_MT_POSITION_X, MIN_X, MAX_X, 0, 0);
210 	input_set_abs_params(input_dev, ABS_MT_POSITION_Y, MIN_Y, MAX_Y, 0, 0);
211 
212 	error = devm_request_threaded_irq(&client->dev, client->irq,
213 					  NULL, st1232_ts_irq_handler,
214 					  IRQF_ONESHOT,
215 					  client->name, ts);
216 	if (error) {
217 		dev_err(&client->dev, "Failed to register interrupt\n");
218 		return error;
219 	}
220 
221 	error = input_register_device(ts->input_dev);
222 	if (error) {
223 		dev_err(&client->dev, "Unable to register %s input device\n",
224 			input_dev->name);
225 		return error;
226 	}
227 
228 	i2c_set_clientdata(client, ts);
229 	device_init_wakeup(&client->dev, 1);
230 
231 	return 0;
232 }
233 
234 static int st1232_ts_remove(struct i2c_client *client)
235 {
236 	struct st1232_ts_data *ts = i2c_get_clientdata(client);
237 
238 	device_init_wakeup(&client->dev, 0);
239 	st1232_ts_power(ts, false);
240 
241 	return 0;
242 }
243 
244 #ifdef CONFIG_PM_SLEEP
245 static int st1232_ts_suspend(struct device *dev)
246 {
247 	struct i2c_client *client = to_i2c_client(dev);
248 	struct st1232_ts_data *ts = i2c_get_clientdata(client);
249 
250 	if (device_may_wakeup(&client->dev)) {
251 		enable_irq_wake(client->irq);
252 	} else {
253 		disable_irq(client->irq);
254 		st1232_ts_power(ts, false);
255 	}
256 
257 	return 0;
258 }
259 
260 static int st1232_ts_resume(struct device *dev)
261 {
262 	struct i2c_client *client = to_i2c_client(dev);
263 	struct st1232_ts_data *ts = i2c_get_clientdata(client);
264 
265 	if (device_may_wakeup(&client->dev)) {
266 		disable_irq_wake(client->irq);
267 	} else {
268 		st1232_ts_power(ts, true);
269 		enable_irq(client->irq);
270 	}
271 
272 	return 0;
273 }
274 
275 #endif
276 
277 static SIMPLE_DEV_PM_OPS(st1232_ts_pm_ops,
278 			 st1232_ts_suspend, st1232_ts_resume);
279 
280 static const struct i2c_device_id st1232_ts_id[] = {
281 	{ ST1232_TS_NAME, 0 },
282 	{ }
283 };
284 MODULE_DEVICE_TABLE(i2c, st1232_ts_id);
285 
286 #ifdef CONFIG_OF
287 static const struct of_device_id st1232_ts_dt_ids[] = {
288 	{ .compatible = "sitronix,st1232", },
289 	{ }
290 };
291 MODULE_DEVICE_TABLE(of, st1232_ts_dt_ids);
292 #endif
293 
294 static struct i2c_driver st1232_ts_driver = {
295 	.probe		= st1232_ts_probe,
296 	.remove		= st1232_ts_remove,
297 	.id_table	= st1232_ts_id,
298 	.driver = {
299 		.name	= ST1232_TS_NAME,
300 		.owner	= THIS_MODULE,
301 		.of_match_table = of_match_ptr(st1232_ts_dt_ids),
302 		.pm	= &st1232_ts_pm_ops,
303 	},
304 };
305 
306 module_i2c_driver(st1232_ts_driver);
307 
308 MODULE_AUTHOR("Tony SIM <chinyeow.sim.xt@renesas.com>");
309 MODULE_DESCRIPTION("SITRONIX ST1232 Touchscreen Controller Driver");
310 MODULE_LICENSE("GPL");
311