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