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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 */
75enum {
76 EVENT_INIT,
77 EVENT_MIDDLE,
78 EVENT_RELEASE,
79 EVENT_FIFO_END
80};
81
82struct max11801_data {
83 struct i2c_client *client;
84 struct input_dev *input_dev;
85};
86
87static 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
93static 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
99static 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 }
154out:
155 return IRQ_HANDLED;
156}
157
158static 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
176static 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
223static const struct i2c_device_id max11801_ts_id[] = {
224 {"max11801", 0},
225 { }
226};
227MODULE_DEVICE_TABLE(i2c, max11801_ts_id);
228
229static struct i2c_driver max11801_ts_driver = {
230 .driver = {
231 .name = "max11801_ts",
232 .owner = THIS_MODULE,
233 },
234 .id_table = max11801_ts_id,
235 .probe = max11801_ts_probe,
236};
237
238module_i2c_driver(max11801_ts_driver);
239
240MODULE_AUTHOR("Zhang Jiejing <jiejing.zhang@freescale.com>");
241MODULE_DESCRIPTION("Touchscreen driver for MAXI MAX11801 controller");
242MODULE_LICENSE("GPL");
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/init.h>
37#include <linux/i2c.h>
38#include <linux/interrupt.h>
39#include <linux/input.h>
40#include <linux/slab.h>
41#include <linux/bitops.h>
42
43/* Register Address define */
44#define GENERNAL_STATUS_REG 0x00
45#define GENERNAL_CONF_REG 0x01
46#define MESURE_RES_CONF_REG 0x02
47#define MESURE_AVER_CONF_REG 0x03
48#define ADC_SAMPLE_TIME_CONF_REG 0x04
49#define PANEL_SETUPTIME_CONF_REG 0x05
50#define DELAY_CONVERSION_CONF_REG 0x06
51#define TOUCH_DETECT_PULLUP_CONF_REG 0x07
52#define AUTO_MODE_TIME_CONF_REG 0x08 /* only for max11800/max11801 */
53#define APERTURE_CONF_REG 0x09 /* only for max11800/max11801 */
54#define AUX_MESURE_CONF_REG 0x0a
55#define OP_MODE_CONF_REG 0x0b
56
57/* FIFO is found only in max11800 and max11801 */
58#define FIFO_RD_CMD (0x50 << 1)
59#define MAX11801_FIFO_INT (1 << 2)
60#define MAX11801_FIFO_OVERFLOW (1 << 3)
61
62#define XY_BUFSIZE 4
63#define XY_BUF_OFFSET 4
64
65#define MAX11801_MAX_X 0xfff
66#define MAX11801_MAX_Y 0xfff
67
68#define MEASURE_TAG_OFFSET 2
69#define MEASURE_TAG_MASK (3 << MEASURE_TAG_OFFSET)
70#define EVENT_TAG_OFFSET 0
71#define EVENT_TAG_MASK (3 << EVENT_TAG_OFFSET)
72#define MEASURE_X_TAG (0 << MEASURE_TAG_OFFSET)
73#define MEASURE_Y_TAG (1 << MEASURE_TAG_OFFSET)
74
75/* These are the state of touch event state machine */
76enum {
77 EVENT_INIT,
78 EVENT_MIDDLE,
79 EVENT_RELEASE,
80 EVENT_FIFO_END
81};
82
83struct max11801_data {
84 struct i2c_client *client;
85 struct input_dev *input_dev;
86};
87
88static u8 read_register(struct i2c_client *client, int addr)
89{
90 /* XXX: The chip ignores LSB of register address */
91 return i2c_smbus_read_byte_data(client, addr << 1);
92}
93
94static int max11801_write_reg(struct i2c_client *client, int addr, int data)
95{
96 /* XXX: The chip ignores LSB of register address */
97 return i2c_smbus_write_byte_data(client, addr << 1, data);
98}
99
100static irqreturn_t max11801_ts_interrupt(int irq, void *dev_id)
101{
102 struct max11801_data *data = dev_id;
103 struct i2c_client *client = data->client;
104 int status, i, ret;
105 u8 buf[XY_BUFSIZE];
106 int x = -1;
107 int y = -1;
108
109 status = read_register(data->client, GENERNAL_STATUS_REG);
110
111 if (status & (MAX11801_FIFO_INT | MAX11801_FIFO_OVERFLOW)) {
112 status = read_register(data->client, GENERNAL_STATUS_REG);
113
114 ret = i2c_smbus_read_i2c_block_data(client, FIFO_RD_CMD,
115 XY_BUFSIZE, buf);
116
117 /*
118 * We should get 4 bytes buffer that contains X,Y
119 * and event tag
120 */
121 if (ret < XY_BUFSIZE)
122 goto out;
123
124 for (i = 0; i < XY_BUFSIZE; i += XY_BUFSIZE / 2) {
125 if ((buf[i + 1] & MEASURE_TAG_MASK) == MEASURE_X_TAG)
126 x = (buf[i] << XY_BUF_OFFSET) +
127 (buf[i + 1] >> XY_BUF_OFFSET);
128 else if ((buf[i + 1] & MEASURE_TAG_MASK) == MEASURE_Y_TAG)
129 y = (buf[i] << XY_BUF_OFFSET) +
130 (buf[i + 1] >> XY_BUF_OFFSET);
131 }
132
133 if ((buf[1] & EVENT_TAG_MASK) != (buf[3] & EVENT_TAG_MASK))
134 goto out;
135
136 switch (buf[1] & EVENT_TAG_MASK) {
137 case EVENT_INIT:
138 /* fall through */
139 case EVENT_MIDDLE:
140 input_report_abs(data->input_dev, ABS_X, x);
141 input_report_abs(data->input_dev, ABS_Y, y);
142 input_event(data->input_dev, EV_KEY, BTN_TOUCH, 1);
143 input_sync(data->input_dev);
144 break;
145
146 case EVENT_RELEASE:
147 input_event(data->input_dev, EV_KEY, BTN_TOUCH, 0);
148 input_sync(data->input_dev);
149 break;
150
151 case EVENT_FIFO_END:
152 break;
153 }
154 }
155out:
156 return IRQ_HANDLED;
157}
158
159static void __devinit max11801_ts_phy_init(struct max11801_data *data)
160{
161 struct i2c_client *client = data->client;
162
163 /* Average X,Y, take 16 samples, average eight media sample */
164 max11801_write_reg(client, MESURE_AVER_CONF_REG, 0xff);
165 /* X,Y panel setup time set to 20us */
166 max11801_write_reg(client, PANEL_SETUPTIME_CONF_REG, 0x11);
167 /* Rough pullup time (2uS), Fine pullup time (10us) */
168 max11801_write_reg(client, TOUCH_DETECT_PULLUP_CONF_REG, 0x10);
169 /* Auto mode init period = 5ms , scan period = 5ms*/
170 max11801_write_reg(client, AUTO_MODE_TIME_CONF_REG, 0xaa);
171 /* Aperture X,Y set to +- 4LSB */
172 max11801_write_reg(client, APERTURE_CONF_REG, 0x33);
173 /* Enable Power, enable Automode, enable Aperture, enable Average X,Y */
174 max11801_write_reg(client, OP_MODE_CONF_REG, 0x36);
175}
176
177static int __devinit max11801_ts_probe(struct i2c_client *client,
178 const struct i2c_device_id *id)
179{
180 struct max11801_data *data;
181 struct input_dev *input_dev;
182 int error;
183
184 data = kzalloc(sizeof(struct max11801_data), GFP_KERNEL);
185 input_dev = input_allocate_device();
186 if (!data || !input_dev) {
187 dev_err(&client->dev, "Failed to allocate memory\n");
188 error = -ENOMEM;
189 goto err_free_mem;
190 }
191
192 data->client = client;
193 data->input_dev = input_dev;
194
195 input_dev->name = "max11801_ts";
196 input_dev->id.bustype = BUS_I2C;
197 input_dev->dev.parent = &client->dev;
198
199 __set_bit(EV_ABS, input_dev->evbit);
200 __set_bit(EV_KEY, input_dev->evbit);
201 __set_bit(BTN_TOUCH, input_dev->keybit);
202 input_set_abs_params(input_dev, ABS_X, 0, MAX11801_MAX_X, 0, 0);
203 input_set_abs_params(input_dev, ABS_Y, 0, MAX11801_MAX_Y, 0, 0);
204 input_set_drvdata(input_dev, data);
205
206 max11801_ts_phy_init(data);
207
208 error = request_threaded_irq(client->irq, NULL, max11801_ts_interrupt,
209 IRQF_TRIGGER_LOW | IRQF_ONESHOT,
210 "max11801_ts", data);
211 if (error) {
212 dev_err(&client->dev, "Failed to register interrupt\n");
213 goto err_free_mem;
214 }
215
216 error = input_register_device(data->input_dev);
217 if (error)
218 goto err_free_irq;
219
220 i2c_set_clientdata(client, data);
221 return 0;
222
223err_free_irq:
224 free_irq(client->irq, data);
225err_free_mem:
226 input_free_device(input_dev);
227 kfree(data);
228 return error;
229}
230
231static __devexit int max11801_ts_remove(struct i2c_client *client)
232{
233 struct max11801_data *data = i2c_get_clientdata(client);
234
235 free_irq(client->irq, data);
236 input_unregister_device(data->input_dev);
237 kfree(data);
238
239 return 0;
240}
241
242static const struct i2c_device_id max11801_ts_id[] = {
243 {"max11801", 0},
244 { }
245};
246MODULE_DEVICE_TABLE(i2c, max11801_ts_id);
247
248static struct i2c_driver max11801_ts_driver = {
249 .driver = {
250 .name = "max11801_ts",
251 .owner = THIS_MODULE,
252 },
253 .id_table = max11801_ts_id,
254 .probe = max11801_ts_probe,
255 .remove = __devexit_p(max11801_ts_remove),
256};
257
258static int __init max11801_ts_init(void)
259{
260 return i2c_add_driver(&max11801_ts_driver);
261}
262
263static void __exit max11801_ts_exit(void)
264{
265 i2c_del_driver(&max11801_ts_driver);
266}
267
268module_init(max11801_ts_init);
269module_exit(max11801_ts_exit);
270
271MODULE_AUTHOR("Zhang Jiejing <jiejing.zhang@freescale.com>");
272MODULE_DESCRIPTION("Touchscreen driver for MAXI MAX11801 controller");
273MODULE_LICENSE("GPL");