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.h>
28 #include <linux/of_gpio.h>
29 #include <linux/pm_qos.h>
30 #include <linux/slab.h>
31 #include <linux/types.h>
32 #include <linux/platform_data/st1232_pdata.h>
33 
34 #define ST1232_TS_NAME	"st1232-ts"
35 
36 #define MIN_X		0x00
37 #define MIN_Y		0x00
38 #define MAX_X		0x31f	/* (800 - 1) */
39 #define MAX_Y		0x1df	/* (480 - 1) */
40 #define MAX_AREA	0xff
41 #define MAX_FINGERS	2
42 
43 struct st1232_ts_finger {
44 	u16 x;
45 	u16 y;
46 	u8 t;
47 	bool is_valid;
48 };
49 
50 struct st1232_ts_data {
51 	struct i2c_client *client;
52 	struct input_dev *input_dev;
53 	struct st1232_ts_finger finger[MAX_FINGERS];
54 	struct dev_pm_qos_request low_latency_req;
55 	int reset_gpio;
56 };
57 
58 static int st1232_ts_read_data(struct st1232_ts_data *ts)
59 {
60 	struct st1232_ts_finger *finger = ts->finger;
61 	struct i2c_client *client = ts->client;
62 	struct i2c_msg msg[2];
63 	int error;
64 	u8 start_reg;
65 	u8 buf[10];
66 
67 	/* read touchscreen data from ST1232 */
68 	msg[0].addr = client->addr;
69 	msg[0].flags = 0;
70 	msg[0].len = 1;
71 	msg[0].buf = &start_reg;
72 	start_reg = 0x10;
73 
74 	msg[1].addr = ts->client->addr;
75 	msg[1].flags = I2C_M_RD;
76 	msg[1].len = sizeof(buf);
77 	msg[1].buf = buf;
78 
79 	error = i2c_transfer(client->adapter, msg, 2);
80 	if (error < 0)
81 		return error;
82 
83 	/* get "valid" bits */
84 	finger[0].is_valid = buf[2] >> 7;
85 	finger[1].is_valid = buf[5] >> 7;
86 
87 	/* get xy coordinate */
88 	if (finger[0].is_valid) {
89 		finger[0].x = ((buf[2] & 0x0070) << 4) | buf[3];
90 		finger[0].y = ((buf[2] & 0x0007) << 8) | buf[4];
91 		finger[0].t = buf[8];
92 	}
93 
94 	if (finger[1].is_valid) {
95 		finger[1].x = ((buf[5] & 0x0070) << 4) | buf[6];
96 		finger[1].y = ((buf[5] & 0x0007) << 8) | buf[7];
97 		finger[1].t = buf[9];
98 	}
99 
100 	return 0;
101 }
102 
103 static irqreturn_t st1232_ts_irq_handler(int irq, void *dev_id)
104 {
105 	struct st1232_ts_data *ts = dev_id;
106 	struct st1232_ts_finger *finger = ts->finger;
107 	struct input_dev *input_dev = ts->input_dev;
108 	int count = 0;
109 	int i, ret;
110 
111 	ret = st1232_ts_read_data(ts);
112 	if (ret < 0)
113 		goto end;
114 
115 	/* multi touch protocol */
116 	for (i = 0; i < MAX_FINGERS; i++) {
117 		if (!finger[i].is_valid)
118 			continue;
119 
120 		input_report_abs(input_dev, ABS_MT_TOUCH_MAJOR, finger[i].t);
121 		input_report_abs(input_dev, ABS_MT_POSITION_X, finger[i].x);
122 		input_report_abs(input_dev, ABS_MT_POSITION_Y, finger[i].y);
123 		input_mt_sync(input_dev);
124 		count++;
125 	}
126 
127 	/* SYN_MT_REPORT only if no contact */
128 	if (!count) {
129 		input_mt_sync(input_dev);
130 		if (ts->low_latency_req.dev) {
131 			dev_pm_qos_remove_request(&ts->low_latency_req);
132 			ts->low_latency_req.dev = NULL;
133 		}
134 	} else if (!ts->low_latency_req.dev) {
135 		/* First contact, request 100 us latency. */
136 		dev_pm_qos_add_ancestor_request(&ts->client->dev,
137 						&ts->low_latency_req,
138 						DEV_PM_QOS_RESUME_LATENCY, 100);
139 	}
140 
141 	/* SYN_REPORT */
142 	input_sync(input_dev);
143 
144 end:
145 	return IRQ_HANDLED;
146 }
147 
148 static void st1232_ts_power(struct st1232_ts_data *ts, bool poweron)
149 {
150 	if (gpio_is_valid(ts->reset_gpio))
151 		gpio_direction_output(ts->reset_gpio, poweron);
152 }
153 
154 static int st1232_ts_probe(struct i2c_client *client,
155 					const struct i2c_device_id *id)
156 {
157 	struct st1232_ts_data *ts;
158 	struct st1232_pdata *pdata = dev_get_platdata(&client->dev);
159 	struct input_dev *input_dev;
160 	int error;
161 
162 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
163 		dev_err(&client->dev, "need I2C_FUNC_I2C\n");
164 		return -EIO;
165 	}
166 
167 	if (!client->irq) {
168 		dev_err(&client->dev, "no IRQ?\n");
169 		return -EINVAL;
170 	}
171 
172 	ts = devm_kzalloc(&client->dev, sizeof(*ts), GFP_KERNEL);
173 	if (!ts)
174 		return -ENOMEM;
175 
176 	input_dev = devm_input_allocate_device(&client->dev);
177 	if (!input_dev)
178 		return -ENOMEM;
179 
180 	ts->client = client;
181 	ts->input_dev = input_dev;
182 
183 	if (pdata)
184 		ts->reset_gpio = pdata->reset_gpio;
185 	else if (client->dev.of_node)
186 		ts->reset_gpio = of_get_gpio(client->dev.of_node, 0);
187 	else
188 		ts->reset_gpio = -ENODEV;
189 
190 	if (gpio_is_valid(ts->reset_gpio)) {
191 		error = devm_gpio_request(&client->dev, ts->reset_gpio, NULL);
192 		if (error) {
193 			dev_err(&client->dev,
194 				"Unable to request GPIO pin %d.\n",
195 				ts->reset_gpio);
196 				return error;
197 		}
198 	}
199 
200 	st1232_ts_power(ts, true);
201 
202 	input_dev->name = "st1232-touchscreen";
203 	input_dev->id.bustype = BUS_I2C;
204 	input_dev->dev.parent = &client->dev;
205 
206 	__set_bit(EV_SYN, input_dev->evbit);
207 	__set_bit(EV_KEY, input_dev->evbit);
208 	__set_bit(EV_ABS, input_dev->evbit);
209 
210 	input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR, 0, MAX_AREA, 0, 0);
211 	input_set_abs_params(input_dev, ABS_MT_POSITION_X, MIN_X, MAX_X, 0, 0);
212 	input_set_abs_params(input_dev, ABS_MT_POSITION_Y, MIN_Y, MAX_Y, 0, 0);
213 
214 	error = devm_request_threaded_irq(&client->dev, client->irq,
215 					  NULL, st1232_ts_irq_handler,
216 					  IRQF_ONESHOT,
217 					  client->name, ts);
218 	if (error) {
219 		dev_err(&client->dev, "Failed to register interrupt\n");
220 		return error;
221 	}
222 
223 	error = input_register_device(ts->input_dev);
224 	if (error) {
225 		dev_err(&client->dev, "Unable to register %s input device\n",
226 			input_dev->name);
227 		return error;
228 	}
229 
230 	i2c_set_clientdata(client, ts);
231 	device_init_wakeup(&client->dev, 1);
232 
233 	return 0;
234 }
235 
236 static int st1232_ts_remove(struct i2c_client *client)
237 {
238 	struct st1232_ts_data *ts = i2c_get_clientdata(client);
239 
240 	device_init_wakeup(&client->dev, 0);
241 	st1232_ts_power(ts, false);
242 
243 	return 0;
244 }
245 
246 #ifdef CONFIG_PM_SLEEP
247 static int st1232_ts_suspend(struct device *dev)
248 {
249 	struct i2c_client *client = to_i2c_client(dev);
250 	struct st1232_ts_data *ts = i2c_get_clientdata(client);
251 
252 	if (device_may_wakeup(&client->dev)) {
253 		enable_irq_wake(client->irq);
254 	} else {
255 		disable_irq(client->irq);
256 		st1232_ts_power(ts, false);
257 	}
258 
259 	return 0;
260 }
261 
262 static int st1232_ts_resume(struct device *dev)
263 {
264 	struct i2c_client *client = to_i2c_client(dev);
265 	struct st1232_ts_data *ts = i2c_get_clientdata(client);
266 
267 	if (device_may_wakeup(&client->dev)) {
268 		disable_irq_wake(client->irq);
269 	} else {
270 		st1232_ts_power(ts, true);
271 		enable_irq(client->irq);
272 	}
273 
274 	return 0;
275 }
276 
277 #endif
278 
279 static SIMPLE_DEV_PM_OPS(st1232_ts_pm_ops,
280 			 st1232_ts_suspend, st1232_ts_resume);
281 
282 static const struct i2c_device_id st1232_ts_id[] = {
283 	{ ST1232_TS_NAME, 0 },
284 	{ }
285 };
286 MODULE_DEVICE_TABLE(i2c, st1232_ts_id);
287 
288 #ifdef CONFIG_OF
289 static const struct of_device_id st1232_ts_dt_ids[] = {
290 	{ .compatible = "sitronix,st1232", },
291 	{ }
292 };
293 MODULE_DEVICE_TABLE(of, st1232_ts_dt_ids);
294 #endif
295 
296 static struct i2c_driver st1232_ts_driver = {
297 	.probe		= st1232_ts_probe,
298 	.remove		= st1232_ts_remove,
299 	.id_table	= st1232_ts_id,
300 	.driver = {
301 		.name	= ST1232_TS_NAME,
302 		.owner	= THIS_MODULE,
303 		.of_match_table = of_match_ptr(st1232_ts_dt_ids),
304 		.pm	= &st1232_ts_pm_ops,
305 	},
306 };
307 
308 module_i2c_driver(st1232_ts_driver);
309 
310 MODULE_AUTHOR("Tony SIM <chinyeow.sim.xt@renesas.com>");
311 MODULE_DESCRIPTION("SITRONIX ST1232 Touchscreen Controller Driver");
312 MODULE_LICENSE("GPL");
313