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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; | |
36682b81 ZJ |
62 | unsigned int statusbits; |
63 | unsigned int keycount; | |
64 | u16 keycodes[MPR121_MAX_KEY_COUNT]; | |
65 | }; | |
66 | ||
67 | struct mpr121_init_register { | |
68 | int addr; | |
69 | u8 val; | |
70 | }; | |
71 | ||
78f50c24 | 72 | static const struct mpr121_init_register init_reg_table[] = { |
36682b81 ZJ |
73 | { MHD_RISING_ADDR, 0x1 }, |
74 | { NHD_RISING_ADDR, 0x1 }, | |
75 | { MHD_FALLING_ADDR, 0x1 }, | |
76 | { NHD_FALLING_ADDR, 0x1 }, | |
77 | { NCL_FALLING_ADDR, 0xff }, | |
78 | { FDL_FALLING_ADDR, 0x02 }, | |
79 | { FILTER_CONF_ADDR, 0x04 }, | |
80 | { AFE_CONF_ADDR, 0x0b }, | |
81 | { AUTO_CONFIG_CTRL_ADDR, 0x0b }, | |
82 | }; | |
83 | ||
84 | static irqreturn_t mpr_touchkey_interrupt(int irq, void *dev_id) | |
85 | { | |
86 | struct mpr121_touchkey *mpr121 = dev_id; | |
87 | struct i2c_client *client = mpr121->client; | |
88 | struct input_dev *input = mpr121->input_dev; | |
89 | unsigned int key_num, key_val, pressed; | |
90 | int reg; | |
91 | ||
92 | reg = i2c_smbus_read_byte_data(client, ELE_TOUCH_STATUS_1_ADDR); | |
93 | if (reg < 0) { | |
94 | dev_err(&client->dev, "i2c read error [%d]\n", reg); | |
95 | goto out; | |
96 | } | |
97 | ||
98 | reg <<= 8; | |
99 | reg |= i2c_smbus_read_byte_data(client, ELE_TOUCH_STATUS_0_ADDR); | |
100 | if (reg < 0) { | |
101 | dev_err(&client->dev, "i2c read error [%d]\n", reg); | |
102 | goto out; | |
103 | } | |
104 | ||
105 | reg &= TOUCH_STATUS_MASK; | |
106 | /* use old press bit to figure out which bit changed */ | |
107 | key_num = ffs(reg ^ mpr121->statusbits) - 1; | |
108 | pressed = reg & (1 << key_num); | |
109 | mpr121->statusbits = reg; | |
110 | ||
111 | key_val = mpr121->keycodes[key_num]; | |
112 | ||
113 | input_event(input, EV_MSC, MSC_SCAN, key_num); | |
114 | input_report_key(input, key_val, pressed); | |
115 | input_sync(input); | |
116 | ||
117 | dev_dbg(&client->dev, "key %d %d %s\n", key_num, key_val, | |
118 | pressed ? "pressed" : "released"); | |
119 | ||
120 | out: | |
121 | return IRQ_HANDLED; | |
122 | } | |
123 | ||
5298cc4c | 124 | static int mpr121_phys_init(const struct mpr121_platform_data *pdata, |
36682b81 ZJ |
125 | struct mpr121_touchkey *mpr121, |
126 | struct i2c_client *client) | |
127 | { | |
128 | const struct mpr121_init_register *reg; | |
c7b4a5d5 | 129 | unsigned char usl, lsl, tl, eleconf; |
36682b81 ZJ |
130 | int i, t, vdd, ret; |
131 | ||
132 | /* Set up touch/release threshold for ele0-ele11 */ | |
133 | for (i = 0; i <= MPR121_MAX_KEY_COUNT; i++) { | |
134 | t = ELE0_TOUCH_THRESHOLD_ADDR + (i * 2); | |
135 | ret = i2c_smbus_write_byte_data(client, t, TOUCH_THRESHOLD); | |
136 | if (ret < 0) | |
137 | goto err_i2c_write; | |
138 | ret = i2c_smbus_write_byte_data(client, t + 1, | |
139 | RELEASE_THRESHOLD); | |
140 | if (ret < 0) | |
141 | goto err_i2c_write; | |
142 | } | |
143 | ||
144 | /* Set up init register */ | |
145 | for (i = 0; i < ARRAY_SIZE(init_reg_table); i++) { | |
146 | reg = &init_reg_table[i]; | |
147 | ret = i2c_smbus_write_byte_data(client, reg->addr, reg->val); | |
148 | if (ret < 0) | |
149 | goto err_i2c_write; | |
150 | } | |
151 | ||
152 | ||
153 | /* | |
154 | * Capacitance on sensing input varies and needs to be compensated. | |
155 | * The internal MPR121-auto-configuration can do this if it's | |
156 | * registers are set properly (based on pdata->vdd_uv). | |
157 | */ | |
158 | vdd = pdata->vdd_uv / 1000; | |
159 | usl = ((vdd - 700) * 256) / vdd; | |
160 | lsl = (usl * 65) / 100; | |
161 | tl = (usl * 90) / 100; | |
162 | ret = i2c_smbus_write_byte_data(client, AUTO_CONFIG_USL_ADDR, usl); | |
163 | ret |= i2c_smbus_write_byte_data(client, AUTO_CONFIG_LSL_ADDR, lsl); | |
164 | ret |= i2c_smbus_write_byte_data(client, AUTO_CONFIG_TL_ADDR, tl); | |
c7b4a5d5 JZ |
165 | |
166 | /* | |
167 | * Quick charge bit will let the capacitive charge to ready | |
168 | * state quickly, or the buttons may not function after system | |
169 | * boot. | |
170 | */ | |
171 | eleconf = mpr121->keycount | ELECTRODE_CONF_QUICK_CHARGE; | |
36682b81 | 172 | ret |= i2c_smbus_write_byte_data(client, ELECTRODE_CONF_ADDR, |
c7b4a5d5 | 173 | eleconf); |
36682b81 ZJ |
174 | if (ret != 0) |
175 | goto err_i2c_write; | |
176 | ||
177 | dev_dbg(&client->dev, "set up with %x keys.\n", mpr121->keycount); | |
178 | ||
179 | return 0; | |
180 | ||
181 | err_i2c_write: | |
182 | dev_err(&client->dev, "i2c write error: %d\n", ret); | |
183 | return ret; | |
184 | } | |
185 | ||
5298cc4c BP |
186 | static int mpr_touchkey_probe(struct i2c_client *client, |
187 | const struct i2c_device_id *id) | |
36682b81 | 188 | { |
c838cb3d JH |
189 | const struct mpr121_platform_data *pdata = |
190 | dev_get_platdata(&client->dev); | |
36682b81 ZJ |
191 | struct mpr121_touchkey *mpr121; |
192 | struct input_dev *input_dev; | |
193 | int error; | |
194 | int i; | |
195 | ||
196 | if (!pdata) { | |
197 | dev_err(&client->dev, "no platform data defined\n"); | |
198 | return -EINVAL; | |
199 | } | |
200 | ||
201 | if (!pdata->keymap || !pdata->keymap_size) { | |
202 | dev_err(&client->dev, "missing keymap data\n"); | |
203 | return -EINVAL; | |
204 | } | |
205 | ||
206 | if (pdata->keymap_size > MPR121_MAX_KEY_COUNT) { | |
207 | dev_err(&client->dev, "too many keys defined\n"); | |
208 | return -EINVAL; | |
209 | } | |
210 | ||
211 | if (!client->irq) { | |
212 | dev_err(&client->dev, "irq number should not be zero\n"); | |
213 | return -EINVAL; | |
214 | } | |
215 | ||
254af0a3 PG |
216 | mpr121 = devm_kzalloc(&client->dev, sizeof(*mpr121), |
217 | GFP_KERNEL); | |
218 | if (!mpr121) | |
219 | return -ENOMEM; | |
220 | ||
221 | input_dev = devm_input_allocate_device(&client->dev); | |
222 | if (!input_dev) | |
223 | return -ENOMEM; | |
36682b81 ZJ |
224 | |
225 | mpr121->client = client; | |
226 | mpr121->input_dev = input_dev; | |
227 | mpr121->keycount = pdata->keymap_size; | |
228 | ||
229 | input_dev->name = "Freescale MPR121 Touchkey"; | |
230 | input_dev->id.bustype = BUS_I2C; | |
231 | input_dev->dev.parent = &client->dev; | |
232 | input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REP); | |
233 | ||
234 | input_dev->keycode = mpr121->keycodes; | |
235 | input_dev->keycodesize = sizeof(mpr121->keycodes[0]); | |
236 | input_dev->keycodemax = mpr121->keycount; | |
237 | ||
238 | for (i = 0; i < pdata->keymap_size; i++) { | |
239 | input_set_capability(input_dev, EV_KEY, pdata->keymap[i]); | |
240 | mpr121->keycodes[i] = pdata->keymap[i]; | |
241 | } | |
242 | ||
243 | error = mpr121_phys_init(pdata, mpr121, client); | |
244 | if (error) { | |
245 | dev_err(&client->dev, "Failed to init register\n"); | |
254af0a3 | 246 | return error; |
36682b81 ZJ |
247 | } |
248 | ||
254af0a3 | 249 | error = devm_request_threaded_irq(&client->dev, client->irq, NULL, |
36682b81 | 250 | mpr_touchkey_interrupt, |
9b7e31bb | 251 | IRQF_TRIGGER_FALLING | IRQF_ONESHOT, |
36682b81 ZJ |
252 | client->dev.driver->name, mpr121); |
253 | if (error) { | |
254 | dev_err(&client->dev, "Failed to register interrupt\n"); | |
254af0a3 | 255 | return error; |
36682b81 ZJ |
256 | } |
257 | ||
258 | error = input_register_device(input_dev); | |
259 | if (error) | |
254af0a3 | 260 | return error; |
36682b81 ZJ |
261 | |
262 | i2c_set_clientdata(client, mpr121); | |
263 | device_init_wakeup(&client->dev, pdata->wakeup); | |
264 | ||
36682b81 ZJ |
265 | return 0; |
266 | } | |
267 | ||
890fa167 | 268 | static int __maybe_unused mpr_suspend(struct device *dev) |
36682b81 ZJ |
269 | { |
270 | struct i2c_client *client = to_i2c_client(dev); | |
271 | ||
272 | if (device_may_wakeup(&client->dev)) | |
273 | enable_irq_wake(client->irq); | |
274 | ||
275 | i2c_smbus_write_byte_data(client, ELECTRODE_CONF_ADDR, 0x00); | |
276 | ||
277 | return 0; | |
278 | } | |
279 | ||
890fa167 | 280 | static int __maybe_unused mpr_resume(struct device *dev) |
36682b81 ZJ |
281 | { |
282 | struct i2c_client *client = to_i2c_client(dev); | |
283 | struct mpr121_touchkey *mpr121 = i2c_get_clientdata(client); | |
284 | ||
285 | if (device_may_wakeup(&client->dev)) | |
286 | disable_irq_wake(client->irq); | |
287 | ||
288 | i2c_smbus_write_byte_data(client, ELECTRODE_CONF_ADDR, | |
289 | mpr121->keycount); | |
290 | ||
291 | return 0; | |
292 | } | |
36682b81 ZJ |
293 | |
294 | static SIMPLE_DEV_PM_OPS(mpr121_touchkey_pm_ops, mpr_suspend, mpr_resume); | |
295 | ||
296 | static const struct i2c_device_id mpr121_id[] = { | |
297 | { "mpr121_touchkey", 0 }, | |
298 | { } | |
299 | }; | |
300 | MODULE_DEVICE_TABLE(i2c, mpr121_id); | |
301 | ||
302 | static struct i2c_driver mpr_touchkey_driver = { | |
303 | .driver = { | |
304 | .name = "mpr121", | |
36682b81 ZJ |
305 | .pm = &mpr121_touchkey_pm_ops, |
306 | }, | |
307 | .id_table = mpr121_id, | |
308 | .probe = mpr_touchkey_probe, | |
36682b81 ZJ |
309 | }; |
310 | ||
1b92c1cf | 311 | module_i2c_driver(mpr_touchkey_driver); |
36682b81 ZJ |
312 | |
313 | MODULE_LICENSE("GPL"); | |
314 | MODULE_AUTHOR("Zhang Jiejing <jiejing.zhang@freescale.com>"); | |
315 | MODULE_DESCRIPTION("Touch Key driver for Freescale MPR121 Chip"); |