1 | /* |
2 | * Touchscreen driver for the tps6507x chip. |
3 | * |
4 | * Copyright (c) 2009 RidgeRun (todd.fischer@ridgerun.com) |
5 | * |
6 | * Credits: |
7 | * |
8 | * Using code from tsc2007, MtekVision Co., Ltd. |
9 | * |
10 | * For licencing details see kernel-base/COPYING |
11 | * |
12 | * TPS65070, TPS65073, TPS650731, and TPS650732 support |
13 | * 10 bit touch screen interface. |
14 | */ |
15 | |
16 | #include <linux/module.h> |
17 | #include <linux/workqueue.h> |
18 | #include <linux/slab.h> |
19 | #include <linux/input.h> |
20 | #include <linux/input-polldev.h> |
21 | #include <linux/platform_device.h> |
22 | #include <linux/mfd/tps6507x.h> |
23 | #include <linux/input/tps6507x-ts.h> |
24 | #include <linux/delay.h> |
25 | |
26 | #define TSC_DEFAULT_POLL_PERIOD 30 /* ms */ |
27 | #define TPS_DEFAULT_MIN_PRESSURE 0x30 |
28 | #define MAX_10BIT ((1 << 10) - 1) |
29 | |
30 | #define TPS6507X_ADCONFIG_CONVERT_TS (TPS6507X_ADCONFIG_AD_ENABLE | \ |
31 | TPS6507X_ADCONFIG_START_CONVERSION | \ |
32 | TPS6507X_ADCONFIG_INPUT_REAL_TSC) |
33 | #define TPS6507X_ADCONFIG_POWER_DOWN_TS (TPS6507X_ADCONFIG_INPUT_REAL_TSC) |
34 | |
35 | struct ts_event { |
36 | u16 x; |
37 | u16 y; |
38 | u16 pressure; |
39 | }; |
40 | |
41 | struct tps6507x_ts { |
42 | struct device *dev; |
43 | struct input_polled_dev *poll_dev; |
44 | struct tps6507x_dev *mfd; |
45 | char phys[32]; |
46 | struct ts_event tc; |
47 | u16 min_pressure; |
48 | bool pendown; |
49 | }; |
50 | |
51 | static int tps6507x_read_u8(struct tps6507x_ts *tsc, u8 reg, u8 *data) |
52 | { |
53 | return tsc->mfd->read_dev(tsc->mfd, reg, 1, data); |
54 | } |
55 | |
56 | static int tps6507x_write_u8(struct tps6507x_ts *tsc, u8 reg, u8 data) |
57 | { |
58 | return tsc->mfd->write_dev(tsc->mfd, reg, 1, &data); |
59 | } |
60 | |
61 | static s32 tps6507x_adc_conversion(struct tps6507x_ts *tsc, |
62 | u8 tsc_mode, u16 *value) |
63 | { |
64 | s32 ret; |
65 | u8 adc_status; |
66 | u8 result; |
67 | |
68 | /* Route input signal to A/D converter */ |
69 | |
70 | ret = tps6507x_write_u8(tsc, TPS6507X_REG_TSCMODE, tsc_mode); |
71 | if (ret) { |
72 | dev_err(tsc->dev, "TSC mode read failed\n" ); |
73 | goto err; |
74 | } |
75 | |
76 | /* Start A/D conversion */ |
77 | |
78 | ret = tps6507x_write_u8(tsc, TPS6507X_REG_ADCONFIG, |
79 | TPS6507X_ADCONFIG_CONVERT_TS); |
80 | if (ret) { |
81 | dev_err(tsc->dev, "ADC config write failed\n" ); |
82 | return ret; |
83 | } |
84 | |
85 | do { |
86 | ret = tps6507x_read_u8(tsc, TPS6507X_REG_ADCONFIG, |
87 | &adc_status); |
88 | if (ret) { |
89 | dev_err(tsc->dev, "ADC config read failed\n" ); |
90 | goto err; |
91 | } |
92 | } while (adc_status & TPS6507X_ADCONFIG_START_CONVERSION); |
93 | |
94 | ret = tps6507x_read_u8(tsc, TPS6507X_REG_ADRESULT_2, &result); |
95 | if (ret) { |
96 | dev_err(tsc->dev, "ADC result 2 read failed\n" ); |
97 | goto err; |
98 | } |
99 | |
100 | *value = (result & TPS6507X_REG_ADRESULT_2_MASK) << 8; |
101 | |
102 | ret = tps6507x_read_u8(tsc, TPS6507X_REG_ADRESULT_1, &result); |
103 | if (ret) { |
104 | dev_err(tsc->dev, "ADC result 1 read failed\n" ); |
105 | goto err; |
106 | } |
107 | |
108 | *value |= result; |
109 | |
110 | dev_dbg(tsc->dev, "TSC channel %d = 0x%X\n" , tsc_mode, *value); |
111 | |
112 | err: |
113 | return ret; |
114 | } |
115 | |
116 | /* Need to call tps6507x_adc_standby() after using A/D converter for the |
117 | * touch screen interrupt to work properly. |
118 | */ |
119 | |
120 | static s32 tps6507x_adc_standby(struct tps6507x_ts *tsc) |
121 | { |
122 | s32 ret; |
123 | s32 loops = 0; |
124 | u8 val; |
125 | |
126 | ret = tps6507x_write_u8(tsc, TPS6507X_REG_ADCONFIG, |
127 | TPS6507X_ADCONFIG_INPUT_TSC); |
128 | if (ret) |
129 | return ret; |
130 | |
131 | ret = tps6507x_write_u8(tsc, TPS6507X_REG_TSCMODE, |
132 | TPS6507X_TSCMODE_STANDBY); |
133 | if (ret) |
134 | return ret; |
135 | |
136 | ret = tps6507x_read_u8(tsc, TPS6507X_REG_INT, &val); |
137 | if (ret) |
138 | return ret; |
139 | |
140 | while (val & TPS6507X_REG_TSC_INT) { |
141 | mdelay(10); |
142 | ret = tps6507x_read_u8(tsc, TPS6507X_REG_INT, &val); |
143 | if (ret) |
144 | return ret; |
145 | loops++; |
146 | } |
147 | |
148 | return ret; |
149 | } |
150 | |
151 | static void tps6507x_ts_poll(struct input_polled_dev *poll_dev) |
152 | { |
153 | struct tps6507x_ts *tsc = poll_dev->private; |
154 | struct input_dev *input_dev = poll_dev->input; |
155 | bool pendown; |
156 | s32 ret; |
157 | |
158 | ret = tps6507x_adc_conversion(tsc, TPS6507X_TSCMODE_PRESSURE, |
159 | &tsc->tc.pressure); |
160 | if (ret) |
161 | goto done; |
162 | |
163 | pendown = tsc->tc.pressure > tsc->min_pressure; |
164 | |
165 | if (unlikely(!pendown && tsc->pendown)) { |
166 | dev_dbg(tsc->dev, "UP\n" ); |
167 | input_report_key(input_dev, BTN_TOUCH, 0); |
168 | input_report_abs(input_dev, ABS_PRESSURE, 0); |
169 | input_sync(input_dev); |
170 | tsc->pendown = false; |
171 | } |
172 | |
173 | if (pendown) { |
174 | |
175 | if (!tsc->pendown) { |
176 | dev_dbg(tsc->dev, "DOWN\n" ); |
177 | input_report_key(input_dev, BTN_TOUCH, 1); |
178 | } else |
179 | dev_dbg(tsc->dev, "still down\n" ); |
180 | |
181 | ret = tps6507x_adc_conversion(tsc, TPS6507X_TSCMODE_X_POSITION, |
182 | &tsc->tc.x); |
183 | if (ret) |
184 | goto done; |
185 | |
186 | ret = tps6507x_adc_conversion(tsc, TPS6507X_TSCMODE_Y_POSITION, |
187 | &tsc->tc.y); |
188 | if (ret) |
189 | goto done; |
190 | |
191 | input_report_abs(input_dev, ABS_X, tsc->tc.x); |
192 | input_report_abs(input_dev, ABS_Y, tsc->tc.y); |
193 | input_report_abs(input_dev, ABS_PRESSURE, tsc->tc.pressure); |
194 | input_sync(input_dev); |
195 | tsc->pendown = true; |
196 | } |
197 | |
198 | done: |
199 | tps6507x_adc_standby(tsc); |
200 | } |
201 | |
202 | static int tps6507x_ts_probe(struct platform_device *pdev) |
203 | { |
204 | struct tps6507x_dev *tps6507x_dev = dev_get_drvdata(pdev->dev.parent); |
205 | const struct tps6507x_board *tps_board; |
206 | const struct touchscreen_init_data *init_data; |
207 | struct tps6507x_ts *tsc; |
208 | struct input_polled_dev *poll_dev; |
209 | struct input_dev *input_dev; |
210 | int error; |
211 | |
212 | /* |
213 | * tps_board points to pmic related constants |
214 | * coming from the board-evm file. |
215 | */ |
216 | tps_board = dev_get_platdata(tps6507x_dev->dev); |
217 | if (!tps_board) { |
218 | dev_err(tps6507x_dev->dev, |
219 | "Could not find tps6507x platform data\n" ); |
220 | return -ENODEV; |
221 | } |
222 | |
223 | /* |
224 | * init_data points to array of regulator_init structures |
225 | * coming from the board-evm file. |
226 | */ |
227 | init_data = tps_board->tps6507x_ts_init_data; |
228 | |
229 | tsc = devm_kzalloc(&pdev->dev, sizeof(struct tps6507x_ts), GFP_KERNEL); |
230 | if (!tsc) { |
231 | dev_err(tps6507x_dev->dev, "failed to allocate driver data\n" ); |
232 | return -ENOMEM; |
233 | } |
234 | |
235 | tsc->mfd = tps6507x_dev; |
236 | tsc->dev = tps6507x_dev->dev; |
237 | tsc->min_pressure = init_data ? |
238 | init_data->min_pressure : TPS_DEFAULT_MIN_PRESSURE; |
239 | |
240 | snprintf(tsc->phys, sizeof(tsc->phys), |
241 | "%s/input0" , dev_name(tsc->dev)); |
242 | |
243 | poll_dev = devm_input_allocate_polled_device(&pdev->dev); |
244 | if (!poll_dev) { |
245 | dev_err(tsc->dev, "Failed to allocate polled input device.\n" ); |
246 | return -ENOMEM; |
247 | } |
248 | |
249 | tsc->poll_dev = poll_dev; |
250 | |
251 | poll_dev->private = tsc; |
252 | poll_dev->poll = tps6507x_ts_poll; |
253 | poll_dev->poll_interval = init_data ? |
254 | init_data->poll_period : TSC_DEFAULT_POLL_PERIOD; |
255 | |
256 | input_dev = poll_dev->input; |
257 | input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS); |
258 | input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH); |
259 | |
260 | input_set_abs_params(input_dev, ABS_X, 0, MAX_10BIT, 0, 0); |
261 | input_set_abs_params(input_dev, ABS_Y, 0, MAX_10BIT, 0, 0); |
262 | input_set_abs_params(input_dev, ABS_PRESSURE, 0, MAX_10BIT, 0, 0); |
263 | |
264 | input_dev->name = "TPS6507x Touchscreen" ; |
265 | input_dev->phys = tsc->phys; |
266 | input_dev->dev.parent = tsc->dev; |
267 | input_dev->id.bustype = BUS_I2C; |
268 | if (init_data) { |
269 | input_dev->id.vendor = init_data->vendor; |
270 | input_dev->id.product = init_data->product; |
271 | input_dev->id.version = init_data->version; |
272 | } |
273 | |
274 | error = tps6507x_adc_standby(tsc); |
275 | if (error) |
276 | return error; |
277 | |
278 | error = input_register_polled_device(poll_dev); |
279 | if (error) |
280 | return error; |
281 | |
282 | return 0; |
283 | } |
284 | |
285 | static struct platform_driver tps6507x_ts_driver = { |
286 | .driver = { |
287 | .name = "tps6507x-ts" , |
288 | }, |
289 | .probe = tps6507x_ts_probe, |
290 | }; |
291 | module_platform_driver(tps6507x_ts_driver); |
292 | |
293 | MODULE_AUTHOR("Todd Fischer <todd.fischer@ridgerun.com>" ); |
294 | MODULE_DESCRIPTION("TPS6507x - TouchScreen driver" ); |
295 | MODULE_LICENSE("GPL v2" ); |
296 | MODULE_ALIAS("platform:tps6507x-ts" ); |
297 | |