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42033065 ZJ |
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 | |
d70d43d7 JZ |
12 | * the Free Software Foundation; either version 2 of the License, or |
13 | * (at your option) any later version. | |
42033065 ZJ |
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> | |
42033065 ZJ |
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 | ||
5298cc4c | 158 | static void max11801_ts_phy_init(struct max11801_data *data) |
42033065 ZJ |
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 | ||
5298cc4c | 176 | static int max11801_ts_probe(struct i2c_client *client, |
42033065 ZJ |
177 | const struct i2c_device_id *id) |
178 | { | |
179 | struct max11801_data *data; | |
180 | struct input_dev *input_dev; | |
181 | int error; | |
182 | ||
d33c4aa3 FE |
183 | data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL); |
184 | input_dev = devm_input_allocate_device(&client->dev); | |
42033065 ZJ |
185 | if (!data || !input_dev) { |
186 | dev_err(&client->dev, "Failed to allocate memory\n"); | |
d33c4aa3 | 187 | return -ENOMEM; |
42033065 ZJ |
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 | ||
d33c4aa3 FE |
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); | |
42033065 ZJ |
210 | if (error) { |
211 | dev_err(&client->dev, "Failed to register interrupt\n"); | |
d33c4aa3 | 212 | return error; |
42033065 ZJ |
213 | } |
214 | ||
215 | error = input_register_device(data->input_dev); | |
216 | if (error) | |
d33c4aa3 | 217 | return error; |
42033065 ZJ |
218 | |
219 | i2c_set_clientdata(client, data); | |
220 | return 0; | |
42033065 ZJ |
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", | |
42033065 ZJ |
232 | }, |
233 | .id_table = max11801_ts_id, | |
234 | .probe = max11801_ts_probe, | |
42033065 ZJ |
235 | }; |
236 | ||
1b92c1cf | 237 | module_i2c_driver(max11801_ts_driver); |
42033065 ZJ |
238 | |
239 | MODULE_AUTHOR("Zhang Jiejing <jiejing.zhang@freescale.com>"); | |
240 | MODULE_DESCRIPTION("Touchscreen driver for MAXI MAX11801 controller"); | |
241 | MODULE_LICENSE("GPL"); |