1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * Driver for MAXI MAX11801 - A Resistive touch screen controller with |
4 | * i2c interface |
5 | * |
6 | * Copyright (C) 2011 Freescale Semiconductor, Inc. |
7 | * Author: Zhang Jiejing <jiejing.zhang@freescale.com> |
8 | * |
9 | * Based on mcs5000_ts.c |
10 | */ |
11 | |
12 | /* |
13 | * This driver aims to support the series of MAXI touch chips max11801 |
14 | * through max11803. The main difference between these 4 chips can be |
15 | * found in the table below: |
16 | * ----------------------------------------------------- |
17 | * | CHIP | AUTO MODE SUPPORT(FIFO) | INTERFACE | |
18 | * |----------------------------------------------------| |
19 | * | max11800 | YES | SPI | |
20 | * | max11801 | YES | I2C | |
21 | * | max11802 | NO | SPI | |
22 | * | max11803 | NO | I2C | |
23 | * ------------------------------------------------------ |
24 | * |
25 | * Currently, this driver only supports max11801. |
26 | * |
27 | * Data Sheet: |
28 | * http://www.maxim-ic.com/datasheet/index.mvp/id/5943 |
29 | */ |
30 | |
31 | #include <linux/module.h> |
32 | #include <linux/i2c.h> |
33 | #include <linux/interrupt.h> |
34 | #include <linux/input.h> |
35 | #include <linux/slab.h> |
36 | #include <linux/bitops.h> |
37 | |
38 | /* Register Address define */ |
39 | #define GENERNAL_STATUS_REG 0x00 |
40 | #define GENERNAL_CONF_REG 0x01 |
41 | #define MESURE_RES_CONF_REG 0x02 |
42 | #define MESURE_AVER_CONF_REG 0x03 |
43 | #define ADC_SAMPLE_TIME_CONF_REG 0x04 |
44 | #define PANEL_SETUPTIME_CONF_REG 0x05 |
45 | #define DELAY_CONVERSION_CONF_REG 0x06 |
46 | #define TOUCH_DETECT_PULLUP_CONF_REG 0x07 |
47 | #define AUTO_MODE_TIME_CONF_REG 0x08 /* only for max11800/max11801 */ |
48 | #define APERTURE_CONF_REG 0x09 /* only for max11800/max11801 */ |
49 | #define AUX_MESURE_CONF_REG 0x0a |
50 | #define OP_MODE_CONF_REG 0x0b |
51 | |
52 | /* FIFO is found only in max11800 and max11801 */ |
53 | #define FIFO_RD_CMD (0x50 << 1) |
54 | #define MAX11801_FIFO_INT (1 << 2) |
55 | #define MAX11801_FIFO_OVERFLOW (1 << 3) |
56 | |
57 | #define XY_BUFSIZE 4 |
58 | #define XY_BUF_OFFSET 4 |
59 | |
60 | #define MAX11801_MAX_X 0xfff |
61 | #define MAX11801_MAX_Y 0xfff |
62 | |
63 | #define MEASURE_TAG_OFFSET 2 |
64 | #define MEASURE_TAG_MASK (3 << MEASURE_TAG_OFFSET) |
65 | #define EVENT_TAG_OFFSET 0 |
66 | #define EVENT_TAG_MASK (3 << EVENT_TAG_OFFSET) |
67 | #define MEASURE_X_TAG (0 << MEASURE_TAG_OFFSET) |
68 | #define MEASURE_Y_TAG (1 << MEASURE_TAG_OFFSET) |
69 | |
70 | /* These are the state of touch event state machine */ |
71 | enum { |
72 | EVENT_INIT, |
73 | EVENT_MIDDLE, |
74 | EVENT_RELEASE, |
75 | EVENT_FIFO_END |
76 | }; |
77 | |
78 | struct max11801_data { |
79 | struct i2c_client *client; |
80 | struct input_dev *input_dev; |
81 | }; |
82 | |
83 | static u8 read_register(struct i2c_client *client, int addr) |
84 | { |
85 | /* XXX: The chip ignores LSB of register address */ |
86 | return i2c_smbus_read_byte_data(client, command: addr << 1); |
87 | } |
88 | |
89 | static int max11801_write_reg(struct i2c_client *client, int addr, int data) |
90 | { |
91 | /* XXX: The chip ignores LSB of register address */ |
92 | return i2c_smbus_write_byte_data(client, command: addr << 1, value: data); |
93 | } |
94 | |
95 | static irqreturn_t max11801_ts_interrupt(int irq, void *dev_id) |
96 | { |
97 | struct max11801_data *data = dev_id; |
98 | struct i2c_client *client = data->client; |
99 | int status, i, ret; |
100 | u8 buf[XY_BUFSIZE]; |
101 | int x = -1; |
102 | int y = -1; |
103 | |
104 | status = read_register(client: data->client, GENERNAL_STATUS_REG); |
105 | |
106 | if (status & (MAX11801_FIFO_INT | MAX11801_FIFO_OVERFLOW)) { |
107 | status = read_register(client: data->client, GENERNAL_STATUS_REG); |
108 | |
109 | ret = i2c_smbus_read_i2c_block_data(client, FIFO_RD_CMD, |
110 | XY_BUFSIZE, values: buf); |
111 | |
112 | /* |
113 | * We should get 4 bytes buffer that contains X,Y |
114 | * and event tag |
115 | */ |
116 | if (ret < XY_BUFSIZE) |
117 | goto out; |
118 | |
119 | for (i = 0; i < XY_BUFSIZE; i += XY_BUFSIZE / 2) { |
120 | if ((buf[i + 1] & MEASURE_TAG_MASK) == MEASURE_X_TAG) |
121 | x = (buf[i] << XY_BUF_OFFSET) + |
122 | (buf[i + 1] >> XY_BUF_OFFSET); |
123 | else if ((buf[i + 1] & MEASURE_TAG_MASK) == MEASURE_Y_TAG) |
124 | y = (buf[i] << XY_BUF_OFFSET) + |
125 | (buf[i + 1] >> XY_BUF_OFFSET); |
126 | } |
127 | |
128 | if ((buf[1] & EVENT_TAG_MASK) != (buf[3] & EVENT_TAG_MASK)) |
129 | goto out; |
130 | |
131 | switch (buf[1] & EVENT_TAG_MASK) { |
132 | case EVENT_INIT: |
133 | case EVENT_MIDDLE: |
134 | input_report_abs(dev: data->input_dev, ABS_X, value: x); |
135 | input_report_abs(dev: data->input_dev, ABS_Y, value: y); |
136 | input_event(dev: data->input_dev, EV_KEY, BTN_TOUCH, value: 1); |
137 | input_sync(dev: data->input_dev); |
138 | break; |
139 | |
140 | case EVENT_RELEASE: |
141 | input_event(dev: data->input_dev, EV_KEY, BTN_TOUCH, value: 0); |
142 | input_sync(dev: data->input_dev); |
143 | break; |
144 | |
145 | case EVENT_FIFO_END: |
146 | break; |
147 | } |
148 | } |
149 | out: |
150 | return IRQ_HANDLED; |
151 | } |
152 | |
153 | static void max11801_ts_phy_init(struct max11801_data *data) |
154 | { |
155 | struct i2c_client *client = data->client; |
156 | |
157 | /* Average X,Y, take 16 samples, average eight media sample */ |
158 | max11801_write_reg(client, MESURE_AVER_CONF_REG, data: 0xff); |
159 | /* X,Y panel setup time set to 20us */ |
160 | max11801_write_reg(client, PANEL_SETUPTIME_CONF_REG, data: 0x11); |
161 | /* Rough pullup time (2uS), Fine pullup time (10us) */ |
162 | max11801_write_reg(client, TOUCH_DETECT_PULLUP_CONF_REG, data: 0x10); |
163 | /* Auto mode init period = 5ms , scan period = 5ms*/ |
164 | max11801_write_reg(client, AUTO_MODE_TIME_CONF_REG, data: 0xaa); |
165 | /* Aperture X,Y set to +- 4LSB */ |
166 | max11801_write_reg(client, APERTURE_CONF_REG, data: 0x33); |
167 | /* Enable Power, enable Automode, enable Aperture, enable Average X,Y */ |
168 | max11801_write_reg(client, OP_MODE_CONF_REG, data: 0x36); |
169 | } |
170 | |
171 | static int max11801_ts_probe(struct i2c_client *client) |
172 | { |
173 | struct max11801_data *data; |
174 | struct input_dev *input_dev; |
175 | int error; |
176 | |
177 | data = devm_kzalloc(dev: &client->dev, size: sizeof(*data), GFP_KERNEL); |
178 | input_dev = devm_input_allocate_device(&client->dev); |
179 | if (!data || !input_dev) { |
180 | dev_err(&client->dev, "Failed to allocate memory\n" ); |
181 | return -ENOMEM; |
182 | } |
183 | |
184 | data->client = client; |
185 | data->input_dev = input_dev; |
186 | |
187 | input_dev->name = "max11801_ts" ; |
188 | input_dev->id.bustype = BUS_I2C; |
189 | input_dev->dev.parent = &client->dev; |
190 | |
191 | __set_bit(EV_ABS, input_dev->evbit); |
192 | __set_bit(EV_KEY, input_dev->evbit); |
193 | __set_bit(BTN_TOUCH, input_dev->keybit); |
194 | input_set_abs_params(dev: input_dev, ABS_X, min: 0, MAX11801_MAX_X, fuzz: 0, flat: 0); |
195 | input_set_abs_params(dev: input_dev, ABS_Y, min: 0, MAX11801_MAX_Y, fuzz: 0, flat: 0); |
196 | |
197 | max11801_ts_phy_init(data); |
198 | |
199 | error = devm_request_threaded_irq(dev: &client->dev, irq: client->irq, NULL, |
200 | thread_fn: max11801_ts_interrupt, |
201 | IRQF_TRIGGER_LOW | IRQF_ONESHOT, |
202 | devname: "max11801_ts" , dev_id: data); |
203 | if (error) { |
204 | dev_err(&client->dev, "Failed to register interrupt\n" ); |
205 | return error; |
206 | } |
207 | |
208 | error = input_register_device(data->input_dev); |
209 | if (error) |
210 | return error; |
211 | |
212 | return 0; |
213 | } |
214 | |
215 | static const struct i2c_device_id max11801_ts_id[] = { |
216 | {"max11801" , 0}, |
217 | { } |
218 | }; |
219 | MODULE_DEVICE_TABLE(i2c, max11801_ts_id); |
220 | |
221 | static const struct of_device_id max11801_ts_dt_ids[] = { |
222 | { .compatible = "maxim,max11801" }, |
223 | { /* sentinel */ } |
224 | }; |
225 | MODULE_DEVICE_TABLE(of, max11801_ts_dt_ids); |
226 | |
227 | static struct i2c_driver max11801_ts_driver = { |
228 | .driver = { |
229 | .name = "max11801_ts" , |
230 | .of_match_table = max11801_ts_dt_ids, |
231 | }, |
232 | .id_table = max11801_ts_id, |
233 | .probe = max11801_ts_probe, |
234 | }; |
235 | |
236 | module_i2c_driver(max11801_ts_driver); |
237 | |
238 | MODULE_AUTHOR("Zhang Jiejing <jiejing.zhang@freescale.com>" ); |
239 | MODULE_DESCRIPTION("Touchscreen driver for MAXI MAX11801 controller" ); |
240 | MODULE_LICENSE("GPL" ); |
241 | |