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Merge branch 'linux-4.6' of git://github.com/skeggsb/linux into drm-fixes
[mirror_ubuntu-bionic-kernel.git] / drivers / input / touchscreen / max11801_ts.c
1 /*
2 * Driver for MAXI MAX11801 - A Resistive touch screen controller with
3 * i2c interface
4 *
5 * Copyright (C) 2011 Freescale Semiconductor, Inc.
6 * Author: Zhang Jiejing <jiejing.zhang@freescale.com>
7 *
8 * Based on mcs5000_ts.c
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
14 */
15
16 /*
17 * This driver aims to support the series of MAXI touch chips max11801
18 * through max11803. The main difference between these 4 chips can be
19 * found in the table below:
20 * -----------------------------------------------------
21 * | CHIP | AUTO MODE SUPPORT(FIFO) | INTERFACE |
22 * |----------------------------------------------------|
23 * | max11800 | YES | SPI |
24 * | max11801 | YES | I2C |
25 * | max11802 | NO | SPI |
26 * | max11803 | NO | I2C |
27 * ------------------------------------------------------
28 *
29 * Currently, this driver only supports max11801.
30 *
31 * Data Sheet:
32 * http://www.maxim-ic.com/datasheet/index.mvp/id/5943
33 */
34
35 #include <linux/module.h>
36 #include <linux/i2c.h>
37 #include <linux/interrupt.h>
38 #include <linux/input.h>
39 #include <linux/slab.h>
40 #include <linux/bitops.h>
41
42 /* Register Address define */
43 #define GENERNAL_STATUS_REG 0x00
44 #define GENERNAL_CONF_REG 0x01
45 #define MESURE_RES_CONF_REG 0x02
46 #define MESURE_AVER_CONF_REG 0x03
47 #define ADC_SAMPLE_TIME_CONF_REG 0x04
48 #define PANEL_SETUPTIME_CONF_REG 0x05
49 #define DELAY_CONVERSION_CONF_REG 0x06
50 #define TOUCH_DETECT_PULLUP_CONF_REG 0x07
51 #define AUTO_MODE_TIME_CONF_REG 0x08 /* only for max11800/max11801 */
52 #define APERTURE_CONF_REG 0x09 /* only for max11800/max11801 */
53 #define AUX_MESURE_CONF_REG 0x0a
54 #define OP_MODE_CONF_REG 0x0b
55
56 /* FIFO is found only in max11800 and max11801 */
57 #define FIFO_RD_CMD (0x50 << 1)
58 #define MAX11801_FIFO_INT (1 << 2)
59 #define MAX11801_FIFO_OVERFLOW (1 << 3)
60
61 #define XY_BUFSIZE 4
62 #define XY_BUF_OFFSET 4
63
64 #define MAX11801_MAX_X 0xfff
65 #define MAX11801_MAX_Y 0xfff
66
67 #define MEASURE_TAG_OFFSET 2
68 #define MEASURE_TAG_MASK (3 << MEASURE_TAG_OFFSET)
69 #define EVENT_TAG_OFFSET 0
70 #define EVENT_TAG_MASK (3 << EVENT_TAG_OFFSET)
71 #define MEASURE_X_TAG (0 << MEASURE_TAG_OFFSET)
72 #define MEASURE_Y_TAG (1 << MEASURE_TAG_OFFSET)
73
74 /* These are the state of touch event state machine */
75 enum {
76 EVENT_INIT,
77 EVENT_MIDDLE,
78 EVENT_RELEASE,
79 EVENT_FIFO_END
80 };
81
82 struct max11801_data {
83 struct i2c_client *client;
84 struct input_dev *input_dev;
85 };
86
87 static u8 read_register(struct i2c_client *client, int addr)
88 {
89 /* XXX: The chip ignores LSB of register address */
90 return i2c_smbus_read_byte_data(client, addr << 1);
91 }
92
93 static int max11801_write_reg(struct i2c_client *client, int addr, int data)
94 {
95 /* XXX: The chip ignores LSB of register address */
96 return i2c_smbus_write_byte_data(client, addr << 1, data);
97 }
98
99 static irqreturn_t max11801_ts_interrupt(int irq, void *dev_id)
100 {
101 struct max11801_data *data = dev_id;
102 struct i2c_client *client = data->client;
103 int status, i, ret;
104 u8 buf[XY_BUFSIZE];
105 int x = -1;
106 int y = -1;
107
108 status = read_register(data->client, GENERNAL_STATUS_REG);
109
110 if (status & (MAX11801_FIFO_INT | MAX11801_FIFO_OVERFLOW)) {
111 status = read_register(data->client, GENERNAL_STATUS_REG);
112
113 ret = i2c_smbus_read_i2c_block_data(client, FIFO_RD_CMD,
114 XY_BUFSIZE, buf);
115
116 /*
117 * We should get 4 bytes buffer that contains X,Y
118 * and event tag
119 */
120 if (ret < XY_BUFSIZE)
121 goto out;
122
123 for (i = 0; i < XY_BUFSIZE; i += XY_BUFSIZE / 2) {
124 if ((buf[i + 1] & MEASURE_TAG_MASK) == MEASURE_X_TAG)
125 x = (buf[i] << XY_BUF_OFFSET) +
126 (buf[i + 1] >> XY_BUF_OFFSET);
127 else if ((buf[i + 1] & MEASURE_TAG_MASK) == MEASURE_Y_TAG)
128 y = (buf[i] << XY_BUF_OFFSET) +
129 (buf[i + 1] >> XY_BUF_OFFSET);
130 }
131
132 if ((buf[1] & EVENT_TAG_MASK) != (buf[3] & EVENT_TAG_MASK))
133 goto out;
134
135 switch (buf[1] & EVENT_TAG_MASK) {
136 case EVENT_INIT:
137 /* fall through */
138 case EVENT_MIDDLE:
139 input_report_abs(data->input_dev, ABS_X, x);
140 input_report_abs(data->input_dev, ABS_Y, y);
141 input_event(data->input_dev, EV_KEY, BTN_TOUCH, 1);
142 input_sync(data->input_dev);
143 break;
144
145 case EVENT_RELEASE:
146 input_event(data->input_dev, EV_KEY, BTN_TOUCH, 0);
147 input_sync(data->input_dev);
148 break;
149
150 case EVENT_FIFO_END:
151 break;
152 }
153 }
154 out:
155 return IRQ_HANDLED;
156 }
157
158 static void max11801_ts_phy_init(struct max11801_data *data)
159 {
160 struct i2c_client *client = data->client;
161
162 /* Average X,Y, take 16 samples, average eight media sample */
163 max11801_write_reg(client, MESURE_AVER_CONF_REG, 0xff);
164 /* X,Y panel setup time set to 20us */
165 max11801_write_reg(client, PANEL_SETUPTIME_CONF_REG, 0x11);
166 /* Rough pullup time (2uS), Fine pullup time (10us) */
167 max11801_write_reg(client, TOUCH_DETECT_PULLUP_CONF_REG, 0x10);
168 /* Auto mode init period = 5ms , scan period = 5ms*/
169 max11801_write_reg(client, AUTO_MODE_TIME_CONF_REG, 0xaa);
170 /* Aperture X,Y set to +- 4LSB */
171 max11801_write_reg(client, APERTURE_CONF_REG, 0x33);
172 /* Enable Power, enable Automode, enable Aperture, enable Average X,Y */
173 max11801_write_reg(client, OP_MODE_CONF_REG, 0x36);
174 }
175
176 static int max11801_ts_probe(struct i2c_client *client,
177 const struct i2c_device_id *id)
178 {
179 struct max11801_data *data;
180 struct input_dev *input_dev;
181 int error;
182
183 data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL);
184 input_dev = devm_input_allocate_device(&client->dev);
185 if (!data || !input_dev) {
186 dev_err(&client->dev, "Failed to allocate memory\n");
187 return -ENOMEM;
188 }
189
190 data->client = client;
191 data->input_dev = input_dev;
192
193 input_dev->name = "max11801_ts";
194 input_dev->id.bustype = BUS_I2C;
195 input_dev->dev.parent = &client->dev;
196
197 __set_bit(EV_ABS, input_dev->evbit);
198 __set_bit(EV_KEY, input_dev->evbit);
199 __set_bit(BTN_TOUCH, input_dev->keybit);
200 input_set_abs_params(input_dev, ABS_X, 0, MAX11801_MAX_X, 0, 0);
201 input_set_abs_params(input_dev, ABS_Y, 0, MAX11801_MAX_Y, 0, 0);
202 input_set_drvdata(input_dev, data);
203
204 max11801_ts_phy_init(data);
205
206 error = devm_request_threaded_irq(&client->dev, client->irq, NULL,
207 max11801_ts_interrupt,
208 IRQF_TRIGGER_LOW | IRQF_ONESHOT,
209 "max11801_ts", data);
210 if (error) {
211 dev_err(&client->dev, "Failed to register interrupt\n");
212 return error;
213 }
214
215 error = input_register_device(data->input_dev);
216 if (error)
217 return error;
218
219 i2c_set_clientdata(client, data);
220 return 0;
221 }
222
223 static const struct i2c_device_id max11801_ts_id[] = {
224 {"max11801", 0},
225 { }
226 };
227 MODULE_DEVICE_TABLE(i2c, max11801_ts_id);
228
229 static struct i2c_driver max11801_ts_driver = {
230 .driver = {
231 .name = "max11801_ts",
232 },
233 .id_table = max11801_ts_id,
234 .probe = max11801_ts_probe,
235 };
236
237 module_i2c_driver(max11801_ts_driver);
238
239 MODULE_AUTHOR("Zhang Jiejing <jiejing.zhang@freescale.com>");
240 MODULE_DESCRIPTION("Touchscreen driver for MAXI MAX11801 controller");
241 MODULE_LICENSE("GPL");