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36682b81 ZJ |
1 | /* |
2 | * Touchkey driver for Freescale MPR121 Controllor | |
3 | * | |
4 | * Copyright (C) 2011 Freescale Semiconductor, Inc. | |
5 | * Author: Zhang Jiejing <jiejing.zhang@freescale.com> | |
6 | * | |
7 | * Based on mcs_touchkey.c | |
8 | * | |
9 | * This program is free software; you can redistribute it and/or modify | |
10 | * it under the terms of the GNU General Public License version 2 as | |
11 | * published by the Free Software Foundation. | |
12 | * | |
13 | */ | |
14 | ||
15 | #include <linux/module.h> | |
36682b81 ZJ |
16 | #include <linux/input.h> |
17 | #include <linux/i2c.h> | |
18 | #include <linux/slab.h> | |
19 | #include <linux/delay.h> | |
20 | #include <linux/bitops.h> | |
21 | #include <linux/interrupt.h> | |
22 | #include <linux/i2c/mpr121_touchkey.h> | |
23 | ||
24 | /* Register definitions */ | |
25 | #define ELE_TOUCH_STATUS_0_ADDR 0x0 | |
26 | #define ELE_TOUCH_STATUS_1_ADDR 0X1 | |
27 | #define MHD_RISING_ADDR 0x2b | |
28 | #define NHD_RISING_ADDR 0x2c | |
29 | #define NCL_RISING_ADDR 0x2d | |
30 | #define FDL_RISING_ADDR 0x2e | |
31 | #define MHD_FALLING_ADDR 0x2f | |
32 | #define NHD_FALLING_ADDR 0x30 | |
33 | #define NCL_FALLING_ADDR 0x31 | |
34 | #define FDL_FALLING_ADDR 0x32 | |
35 | #define ELE0_TOUCH_THRESHOLD_ADDR 0x41 | |
36 | #define ELE0_RELEASE_THRESHOLD_ADDR 0x42 | |
37 | #define AFE_CONF_ADDR 0x5c | |
38 | #define FILTER_CONF_ADDR 0x5d | |
39 | ||
40 | /* | |
41 | * ELECTRODE_CONF_ADDR: This register configures the number of | |
42 | * enabled capacitance sensing inputs and its run/suspend mode. | |
43 | */ | |
44 | #define ELECTRODE_CONF_ADDR 0x5e | |
c7b4a5d5 | 45 | #define ELECTRODE_CONF_QUICK_CHARGE 0x80 |
36682b81 ZJ |
46 | #define AUTO_CONFIG_CTRL_ADDR 0x7b |
47 | #define AUTO_CONFIG_USL_ADDR 0x7d | |
48 | #define AUTO_CONFIG_LSL_ADDR 0x7e | |
49 | #define AUTO_CONFIG_TL_ADDR 0x7f | |
50 | ||
51 | /* Threshold of touch/release trigger */ | |
c7b4a5d5 JZ |
52 | #define TOUCH_THRESHOLD 0x08 |
53 | #define RELEASE_THRESHOLD 0x05 | |
36682b81 ZJ |
54 | /* Masks for touch and release triggers */ |
55 | #define TOUCH_STATUS_MASK 0xfff | |
56 | /* MPR121 has 12 keys */ | |
57 | #define MPR121_MAX_KEY_COUNT 12 | |
58 | ||
59 | struct mpr121_touchkey { | |
60 | struct i2c_client *client; | |
61 | struct input_dev *input_dev; | |
62 | unsigned int key_val; | |
63 | unsigned int statusbits; | |
64 | unsigned int keycount; | |
65 | u16 keycodes[MPR121_MAX_KEY_COUNT]; | |
66 | }; | |
67 | ||
68 | struct mpr121_init_register { | |
69 | int addr; | |
70 | u8 val; | |
71 | }; | |
72 | ||
78f50c24 | 73 | static const struct mpr121_init_register init_reg_table[] = { |
36682b81 ZJ |
74 | { MHD_RISING_ADDR, 0x1 }, |
75 | { NHD_RISING_ADDR, 0x1 }, | |
76 | { MHD_FALLING_ADDR, 0x1 }, | |
77 | { NHD_FALLING_ADDR, 0x1 }, | |
78 | { NCL_FALLING_ADDR, 0xff }, | |
79 | { FDL_FALLING_ADDR, 0x02 }, | |
80 | { FILTER_CONF_ADDR, 0x04 }, | |
81 | { AFE_CONF_ADDR, 0x0b }, | |
82 | { AUTO_CONFIG_CTRL_ADDR, 0x0b }, | |
83 | }; | |
84 | ||
85 | static irqreturn_t mpr_touchkey_interrupt(int irq, void *dev_id) | |
86 | { | |
87 | struct mpr121_touchkey *mpr121 = dev_id; | |
88 | struct i2c_client *client = mpr121->client; | |
89 | struct input_dev *input = mpr121->input_dev; | |
90 | unsigned int key_num, key_val, pressed; | |
91 | int reg; | |
92 | ||
93 | reg = i2c_smbus_read_byte_data(client, ELE_TOUCH_STATUS_1_ADDR); | |
94 | if (reg < 0) { | |
95 | dev_err(&client->dev, "i2c read error [%d]\n", reg); | |
96 | goto out; | |
97 | } | |
98 | ||
99 | reg <<= 8; | |
100 | reg |= i2c_smbus_read_byte_data(client, ELE_TOUCH_STATUS_0_ADDR); | |
101 | if (reg < 0) { | |
102 | dev_err(&client->dev, "i2c read error [%d]\n", reg); | |
103 | goto out; | |
104 | } | |
105 | ||
106 | reg &= TOUCH_STATUS_MASK; | |
107 | /* use old press bit to figure out which bit changed */ | |
108 | key_num = ffs(reg ^ mpr121->statusbits) - 1; | |
109 | pressed = reg & (1 << key_num); | |
110 | mpr121->statusbits = reg; | |
111 | ||
112 | key_val = mpr121->keycodes[key_num]; | |
113 | ||
114 | input_event(input, EV_MSC, MSC_SCAN, key_num); | |
115 | input_report_key(input, key_val, pressed); | |
116 | input_sync(input); | |
117 | ||
118 | dev_dbg(&client->dev, "key %d %d %s\n", key_num, key_val, | |
119 | pressed ? "pressed" : "released"); | |
120 | ||
121 | out: | |
122 | return IRQ_HANDLED; | |
123 | } | |
124 | ||
5298cc4c | 125 | static int mpr121_phys_init(const struct mpr121_platform_data *pdata, |
36682b81 ZJ |
126 | struct mpr121_touchkey *mpr121, |
127 | struct i2c_client *client) | |
128 | { | |
129 | const struct mpr121_init_register *reg; | |
c7b4a5d5 | 130 | unsigned char usl, lsl, tl, eleconf; |
36682b81 ZJ |
131 | int i, t, vdd, ret; |
132 | ||
133 | /* Set up touch/release threshold for ele0-ele11 */ | |
134 | for (i = 0; i <= MPR121_MAX_KEY_COUNT; i++) { | |
135 | t = ELE0_TOUCH_THRESHOLD_ADDR + (i * 2); | |
136 | ret = i2c_smbus_write_byte_data(client, t, TOUCH_THRESHOLD); | |
137 | if (ret < 0) | |
138 | goto err_i2c_write; | |
139 | ret = i2c_smbus_write_byte_data(client, t + 1, | |
140 | RELEASE_THRESHOLD); | |
141 | if (ret < 0) | |
142 | goto err_i2c_write; | |
143 | } | |
144 | ||
145 | /* Set up init register */ | |
146 | for (i = 0; i < ARRAY_SIZE(init_reg_table); i++) { | |
147 | reg = &init_reg_table[i]; | |
148 | ret = i2c_smbus_write_byte_data(client, reg->addr, reg->val); | |
149 | if (ret < 0) | |
150 | goto err_i2c_write; | |
151 | } | |
152 | ||
153 | ||
154 | /* | |
155 | * Capacitance on sensing input varies and needs to be compensated. | |
156 | * The internal MPR121-auto-configuration can do this if it's | |
157 | * registers are set properly (based on pdata->vdd_uv). | |
158 | */ | |
159 | vdd = pdata->vdd_uv / 1000; | |
160 | usl = ((vdd - 700) * 256) / vdd; | |
161 | lsl = (usl * 65) / 100; | |
162 | tl = (usl * 90) / 100; | |
163 | ret = i2c_smbus_write_byte_data(client, AUTO_CONFIG_USL_ADDR, usl); | |
164 | ret |= i2c_smbus_write_byte_data(client, AUTO_CONFIG_LSL_ADDR, lsl); | |
165 | ret |= i2c_smbus_write_byte_data(client, AUTO_CONFIG_TL_ADDR, tl); | |
c7b4a5d5 JZ |
166 | |
167 | /* | |
168 | * Quick charge bit will let the capacitive charge to ready | |
169 | * state quickly, or the buttons may not function after system | |
170 | * boot. | |
171 | */ | |
172 | eleconf = mpr121->keycount | ELECTRODE_CONF_QUICK_CHARGE; | |
36682b81 | 173 | ret |= i2c_smbus_write_byte_data(client, ELECTRODE_CONF_ADDR, |
c7b4a5d5 | 174 | eleconf); |
36682b81 ZJ |
175 | if (ret != 0) |
176 | goto err_i2c_write; | |
177 | ||
178 | dev_dbg(&client->dev, "set up with %x keys.\n", mpr121->keycount); | |
179 | ||
180 | return 0; | |
181 | ||
182 | err_i2c_write: | |
183 | dev_err(&client->dev, "i2c write error: %d\n", ret); | |
184 | return ret; | |
185 | } | |
186 | ||
5298cc4c BP |
187 | static int mpr_touchkey_probe(struct i2c_client *client, |
188 | const struct i2c_device_id *id) | |
36682b81 | 189 | { |
c838cb3d JH |
190 | const struct mpr121_platform_data *pdata = |
191 | dev_get_platdata(&client->dev); | |
36682b81 ZJ |
192 | struct mpr121_touchkey *mpr121; |
193 | struct input_dev *input_dev; | |
194 | int error; | |
195 | int i; | |
196 | ||
197 | if (!pdata) { | |
198 | dev_err(&client->dev, "no platform data defined\n"); | |
199 | return -EINVAL; | |
200 | } | |
201 | ||
202 | if (!pdata->keymap || !pdata->keymap_size) { | |
203 | dev_err(&client->dev, "missing keymap data\n"); | |
204 | return -EINVAL; | |
205 | } | |
206 | ||
207 | if (pdata->keymap_size > MPR121_MAX_KEY_COUNT) { | |
208 | dev_err(&client->dev, "too many keys defined\n"); | |
209 | return -EINVAL; | |
210 | } | |
211 | ||
212 | if (!client->irq) { | |
213 | dev_err(&client->dev, "irq number should not be zero\n"); | |
214 | return -EINVAL; | |
215 | } | |
216 | ||
254af0a3 PG |
217 | mpr121 = devm_kzalloc(&client->dev, sizeof(*mpr121), |
218 | GFP_KERNEL); | |
219 | if (!mpr121) | |
220 | return -ENOMEM; | |
221 | ||
222 | input_dev = devm_input_allocate_device(&client->dev); | |
223 | if (!input_dev) | |
224 | return -ENOMEM; | |
36682b81 ZJ |
225 | |
226 | mpr121->client = client; | |
227 | mpr121->input_dev = input_dev; | |
228 | mpr121->keycount = pdata->keymap_size; | |
229 | ||
230 | input_dev->name = "Freescale MPR121 Touchkey"; | |
231 | input_dev->id.bustype = BUS_I2C; | |
232 | input_dev->dev.parent = &client->dev; | |
233 | input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REP); | |
234 | ||
235 | input_dev->keycode = mpr121->keycodes; | |
236 | input_dev->keycodesize = sizeof(mpr121->keycodes[0]); | |
237 | input_dev->keycodemax = mpr121->keycount; | |
238 | ||
239 | for (i = 0; i < pdata->keymap_size; i++) { | |
240 | input_set_capability(input_dev, EV_KEY, pdata->keymap[i]); | |
241 | mpr121->keycodes[i] = pdata->keymap[i]; | |
242 | } | |
243 | ||
244 | error = mpr121_phys_init(pdata, mpr121, client); | |
245 | if (error) { | |
246 | dev_err(&client->dev, "Failed to init register\n"); | |
254af0a3 | 247 | return error; |
36682b81 ZJ |
248 | } |
249 | ||
254af0a3 | 250 | error = devm_request_threaded_irq(&client->dev, client->irq, NULL, |
36682b81 | 251 | mpr_touchkey_interrupt, |
9b7e31bb | 252 | IRQF_TRIGGER_FALLING | IRQF_ONESHOT, |
36682b81 ZJ |
253 | client->dev.driver->name, mpr121); |
254 | if (error) { | |
255 | dev_err(&client->dev, "Failed to register interrupt\n"); | |
254af0a3 | 256 | return error; |
36682b81 ZJ |
257 | } |
258 | ||
259 | error = input_register_device(input_dev); | |
260 | if (error) | |
254af0a3 | 261 | return error; |
36682b81 ZJ |
262 | |
263 | i2c_set_clientdata(client, mpr121); | |
264 | device_init_wakeup(&client->dev, pdata->wakeup); | |
265 | ||
36682b81 ZJ |
266 | return 0; |
267 | } | |
268 | ||
269 | #ifdef CONFIG_PM_SLEEP | |
270 | static int mpr_suspend(struct device *dev) | |
271 | { | |
272 | struct i2c_client *client = to_i2c_client(dev); | |
273 | ||
274 | if (device_may_wakeup(&client->dev)) | |
275 | enable_irq_wake(client->irq); | |
276 | ||
277 | i2c_smbus_write_byte_data(client, ELECTRODE_CONF_ADDR, 0x00); | |
278 | ||
279 | return 0; | |
280 | } | |
281 | ||
282 | static int mpr_resume(struct device *dev) | |
283 | { | |
284 | struct i2c_client *client = to_i2c_client(dev); | |
285 | struct mpr121_touchkey *mpr121 = i2c_get_clientdata(client); | |
286 | ||
287 | if (device_may_wakeup(&client->dev)) | |
288 | disable_irq_wake(client->irq); | |
289 | ||
290 | i2c_smbus_write_byte_data(client, ELECTRODE_CONF_ADDR, | |
291 | mpr121->keycount); | |
292 | ||
293 | return 0; | |
294 | } | |
295 | #endif | |
296 | ||
297 | static SIMPLE_DEV_PM_OPS(mpr121_touchkey_pm_ops, mpr_suspend, mpr_resume); | |
298 | ||
299 | static const struct i2c_device_id mpr121_id[] = { | |
300 | { "mpr121_touchkey", 0 }, | |
301 | { } | |
302 | }; | |
303 | MODULE_DEVICE_TABLE(i2c, mpr121_id); | |
304 | ||
305 | static struct i2c_driver mpr_touchkey_driver = { | |
306 | .driver = { | |
307 | .name = "mpr121", | |
308 | .owner = THIS_MODULE, | |
309 | .pm = &mpr121_touchkey_pm_ops, | |
310 | }, | |
311 | .id_table = mpr121_id, | |
312 | .probe = mpr_touchkey_probe, | |
36682b81 ZJ |
313 | }; |
314 | ||
1b92c1cf | 315 | module_i2c_driver(mpr_touchkey_driver); |
36682b81 ZJ |
316 | |
317 | MODULE_LICENSE("GPL"); | |
318 | MODULE_AUTHOR("Zhang Jiejing <jiejing.zhang@freescale.com>"); | |
319 | MODULE_DESCRIPTION("Touch Key driver for Freescale MPR121 Chip"); |