1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * STMicroelectronics STMPE811 Touchscreen Driver |
4 | * |
5 | * (C) 2010 Luotao Fu <l.fu@pengutronix.de> |
6 | * All rights reserved. |
7 | */ |
8 | |
9 | #include <linux/kernel.h> |
10 | #include <linux/module.h> |
11 | #include <linux/sched.h> |
12 | #include <linux/interrupt.h> |
13 | #include <linux/device.h> |
14 | #include <linux/of.h> |
15 | #include <linux/platform_device.h> |
16 | #include <linux/input.h> |
17 | #include <linux/input/touchscreen.h> |
18 | #include <linux/slab.h> |
19 | #include <linux/delay.h> |
20 | #include <linux/i2c.h> |
21 | #include <linux/workqueue.h> |
22 | |
23 | #include <linux/mfd/stmpe.h> |
24 | |
25 | /* Register layouts and functionalities are identical on all stmpexxx variants |
26 | * with touchscreen controller |
27 | */ |
28 | #define STMPE_REG_INT_STA 0x0B |
29 | #define STMPE_REG_TSC_CTRL 0x40 |
30 | #define STMPE_REG_TSC_CFG 0x41 |
31 | #define STMPE_REG_FIFO_TH 0x4A |
32 | #define STMPE_REG_FIFO_STA 0x4B |
33 | #define STMPE_REG_FIFO_SIZE 0x4C |
34 | #define STMPE_REG_TSC_DATA_XYZ 0x52 |
35 | #define STMPE_REG_TSC_FRACTION_Z 0x56 |
36 | #define STMPE_REG_TSC_I_DRIVE 0x58 |
37 | |
38 | #define OP_MOD_XYZ 0 |
39 | |
40 | #define STMPE_TSC_CTRL_TSC_EN (1<<0) |
41 | |
42 | #define STMPE_FIFO_STA_RESET (1<<0) |
43 | |
44 | #define STMPE_IRQ_TOUCH_DET 0 |
45 | |
46 | #define STMPE_TS_NAME "stmpe-ts" |
47 | #define XY_MASK 0xfff |
48 | |
49 | /** |
50 | * struct stmpe_touch - stmpe811 touch screen controller state |
51 | * @stmpe: pointer back to STMPE MFD container |
52 | * @idev: registered input device |
53 | * @work: a work item used to scan the device |
54 | * @dev: a pointer back to the MFD cell struct device* |
55 | * @prop: Touchscreen properties |
56 | * @ave_ctrl: Sample average control |
57 | * (0 -> 1 sample, 1 -> 2 samples, 2 -> 4 samples, 3 -> 8 samples) |
58 | * @touch_det_delay: Touch detect interrupt delay |
59 | * (0 -> 10 us, 1 -> 50 us, 2 -> 100 us, 3 -> 500 us, |
60 | * 4-> 1 ms, 5 -> 5 ms, 6 -> 10 ms, 7 -> 50 ms) |
61 | * recommended is 3 |
62 | * @settling: Panel driver settling time |
63 | * (0 -> 10 us, 1 -> 100 us, 2 -> 500 us, 3 -> 1 ms, |
64 | * 4 -> 5 ms, 5 -> 10 ms, 6 for 50 ms, 7 -> 100 ms) |
65 | * recommended is 2 |
66 | * @fraction_z: Length of the fractional part in z |
67 | * (fraction_z ([0..7]) = Count of the fractional part) |
68 | * recommended is 7 |
69 | * @i_drive: current limit value of the touchscreen drivers |
70 | * (0 -> 20 mA typical 35 mA max, 1 -> 50 mA typical 80 mA max) |
71 | */ |
72 | struct stmpe_touch { |
73 | struct stmpe *stmpe; |
74 | struct input_dev *idev; |
75 | struct delayed_work work; |
76 | struct device *dev; |
77 | struct touchscreen_properties prop; |
78 | u8 ave_ctrl; |
79 | u8 touch_det_delay; |
80 | u8 settling; |
81 | u8 fraction_z; |
82 | u8 i_drive; |
83 | }; |
84 | |
85 | static int __stmpe_reset_fifo(struct stmpe *stmpe) |
86 | { |
87 | int ret; |
88 | |
89 | ret = stmpe_set_bits(stmpe, STMPE_REG_FIFO_STA, |
90 | STMPE_FIFO_STA_RESET, STMPE_FIFO_STA_RESET); |
91 | if (ret) |
92 | return ret; |
93 | |
94 | return stmpe_set_bits(stmpe, STMPE_REG_FIFO_STA, |
95 | STMPE_FIFO_STA_RESET, val: 0); |
96 | } |
97 | |
98 | static void stmpe_work(struct work_struct *work) |
99 | { |
100 | int int_sta; |
101 | u32 timeout = 40; |
102 | |
103 | struct stmpe_touch *ts = |
104 | container_of(work, struct stmpe_touch, work.work); |
105 | |
106 | int_sta = stmpe_reg_read(stmpe: ts->stmpe, STMPE_REG_INT_STA); |
107 | |
108 | /* |
109 | * touch_det sometimes get desasserted or just get stuck. This appears |
110 | * to be a silicon bug, We still have to clearify this with the |
111 | * manufacture. As a workaround We release the key anyway if the |
112 | * touch_det keeps coming in after 4ms, while the FIFO contains no value |
113 | * during the whole time. |
114 | */ |
115 | while ((int_sta & (1 << STMPE_IRQ_TOUCH_DET)) && (timeout > 0)) { |
116 | timeout--; |
117 | int_sta = stmpe_reg_read(stmpe: ts->stmpe, STMPE_REG_INT_STA); |
118 | udelay(100); |
119 | } |
120 | |
121 | /* reset the FIFO before we report release event */ |
122 | __stmpe_reset_fifo(stmpe: ts->stmpe); |
123 | |
124 | input_report_abs(dev: ts->idev, ABS_PRESSURE, value: 0); |
125 | input_report_key(dev: ts->idev, BTN_TOUCH, value: 0); |
126 | input_sync(dev: ts->idev); |
127 | } |
128 | |
129 | static irqreturn_t stmpe_ts_handler(int irq, void *data) |
130 | { |
131 | u8 data_set[4]; |
132 | int x, y, z; |
133 | struct stmpe_touch *ts = data; |
134 | |
135 | /* |
136 | * Cancel scheduled polling for release if we have new value |
137 | * available. Wait if the polling is already running. |
138 | */ |
139 | cancel_delayed_work_sync(dwork: &ts->work); |
140 | |
141 | /* |
142 | * The FIFO sometimes just crashes and stops generating interrupts. This |
143 | * appears to be a silicon bug. We still have to clearify this with |
144 | * the manufacture. As a workaround we disable the TSC while we are |
145 | * collecting data and flush the FIFO after reading |
146 | */ |
147 | stmpe_set_bits(stmpe: ts->stmpe, STMPE_REG_TSC_CTRL, |
148 | STMPE_TSC_CTRL_TSC_EN, val: 0); |
149 | |
150 | stmpe_block_read(stmpe: ts->stmpe, STMPE_REG_TSC_DATA_XYZ, length: 4, values: data_set); |
151 | |
152 | x = (data_set[0] << 4) | (data_set[1] >> 4); |
153 | y = ((data_set[1] & 0xf) << 8) | data_set[2]; |
154 | z = data_set[3]; |
155 | |
156 | touchscreen_report_pos(input: ts->idev, prop: &ts->prop, x, y, multitouch: false); |
157 | input_report_abs(dev: ts->idev, ABS_PRESSURE, value: z); |
158 | input_report_key(dev: ts->idev, BTN_TOUCH, value: 1); |
159 | input_sync(dev: ts->idev); |
160 | |
161 | /* flush the FIFO after we have read out our values. */ |
162 | __stmpe_reset_fifo(stmpe: ts->stmpe); |
163 | |
164 | /* reenable the tsc */ |
165 | stmpe_set_bits(stmpe: ts->stmpe, STMPE_REG_TSC_CTRL, |
166 | STMPE_TSC_CTRL_TSC_EN, STMPE_TSC_CTRL_TSC_EN); |
167 | |
168 | /* start polling for touch_det to detect release */ |
169 | schedule_delayed_work(dwork: &ts->work, delay: msecs_to_jiffies(m: 50)); |
170 | |
171 | return IRQ_HANDLED; |
172 | } |
173 | |
174 | static int stmpe_init_hw(struct stmpe_touch *ts) |
175 | { |
176 | int ret; |
177 | u8 tsc_cfg, tsc_cfg_mask; |
178 | struct stmpe *stmpe = ts->stmpe; |
179 | struct device *dev = ts->dev; |
180 | |
181 | ret = stmpe_enable(stmpe, blocks: STMPE_BLOCK_TOUCHSCREEN | STMPE_BLOCK_ADC); |
182 | if (ret) { |
183 | dev_err(dev, "Could not enable clock for ADC and TS\n" ); |
184 | return ret; |
185 | } |
186 | |
187 | ret = stmpe811_adc_common_init(stmpe); |
188 | if (ret) { |
189 | stmpe_disable(stmpe, blocks: STMPE_BLOCK_TOUCHSCREEN | STMPE_BLOCK_ADC); |
190 | return ret; |
191 | } |
192 | |
193 | tsc_cfg = STMPE_AVE_CTRL(ts->ave_ctrl) | |
194 | STMPE_DET_DELAY(ts->touch_det_delay) | |
195 | STMPE_SETTLING(ts->settling); |
196 | tsc_cfg_mask = STMPE_AVE_CTRL(0xff) | STMPE_DET_DELAY(0xff) | |
197 | STMPE_SETTLING(0xff); |
198 | |
199 | ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_CFG, mask: tsc_cfg_mask, val: tsc_cfg); |
200 | if (ret) { |
201 | dev_err(dev, "Could not config touch\n" ); |
202 | return ret; |
203 | } |
204 | |
205 | ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_FRACTION_Z, |
206 | STMPE_FRACTION_Z(0xff), STMPE_FRACTION_Z(ts->fraction_z)); |
207 | if (ret) { |
208 | dev_err(dev, "Could not config touch\n" ); |
209 | return ret; |
210 | } |
211 | |
212 | ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_I_DRIVE, |
213 | STMPE_I_DRIVE(0xff), STMPE_I_DRIVE(ts->i_drive)); |
214 | if (ret) { |
215 | dev_err(dev, "Could not config touch\n" ); |
216 | return ret; |
217 | } |
218 | |
219 | /* set FIFO to 1 for single point reading */ |
220 | ret = stmpe_reg_write(stmpe, STMPE_REG_FIFO_TH, data: 1); |
221 | if (ret) { |
222 | dev_err(dev, "Could not set FIFO\n" ); |
223 | return ret; |
224 | } |
225 | |
226 | ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_CTRL, |
227 | STMPE_OP_MODE(0xff), STMPE_OP_MODE(OP_MOD_XYZ)); |
228 | if (ret) { |
229 | dev_err(dev, "Could not set mode\n" ); |
230 | return ret; |
231 | } |
232 | |
233 | return 0; |
234 | } |
235 | |
236 | static int stmpe_ts_open(struct input_dev *dev) |
237 | { |
238 | struct stmpe_touch *ts = input_get_drvdata(dev); |
239 | int ret = 0; |
240 | |
241 | ret = __stmpe_reset_fifo(stmpe: ts->stmpe); |
242 | if (ret) |
243 | return ret; |
244 | |
245 | return stmpe_set_bits(stmpe: ts->stmpe, STMPE_REG_TSC_CTRL, |
246 | STMPE_TSC_CTRL_TSC_EN, STMPE_TSC_CTRL_TSC_EN); |
247 | } |
248 | |
249 | static void stmpe_ts_close(struct input_dev *dev) |
250 | { |
251 | struct stmpe_touch *ts = input_get_drvdata(dev); |
252 | |
253 | cancel_delayed_work_sync(dwork: &ts->work); |
254 | |
255 | stmpe_set_bits(stmpe: ts->stmpe, STMPE_REG_TSC_CTRL, |
256 | STMPE_TSC_CTRL_TSC_EN, val: 0); |
257 | } |
258 | |
259 | static void stmpe_ts_get_platform_info(struct platform_device *pdev, |
260 | struct stmpe_touch *ts) |
261 | { |
262 | struct device_node *np = pdev->dev.of_node; |
263 | u32 val; |
264 | |
265 | if (np) { |
266 | if (!of_property_read_u32(np, propname: "st,sample-time" , out_value: &val)) |
267 | ts->stmpe->sample_time = val; |
268 | if (!of_property_read_u32(np, propname: "st,mod-12b" , out_value: &val)) |
269 | ts->stmpe->mod_12b = val; |
270 | if (!of_property_read_u32(np, propname: "st,ref-sel" , out_value: &val)) |
271 | ts->stmpe->ref_sel = val; |
272 | if (!of_property_read_u32(np, propname: "st,adc-freq" , out_value: &val)) |
273 | ts->stmpe->adc_freq = val; |
274 | if (!of_property_read_u32(np, propname: "st,ave-ctrl" , out_value: &val)) |
275 | ts->ave_ctrl = val; |
276 | if (!of_property_read_u32(np, propname: "st,touch-det-delay" , out_value: &val)) |
277 | ts->touch_det_delay = val; |
278 | if (!of_property_read_u32(np, propname: "st,settling" , out_value: &val)) |
279 | ts->settling = val; |
280 | if (!of_property_read_u32(np, propname: "st,fraction-z" , out_value: &val)) |
281 | ts->fraction_z = val; |
282 | if (!of_property_read_u32(np, propname: "st,i-drive" , out_value: &val)) |
283 | ts->i_drive = val; |
284 | } |
285 | } |
286 | |
287 | static int stmpe_input_probe(struct platform_device *pdev) |
288 | { |
289 | struct stmpe *stmpe = dev_get_drvdata(dev: pdev->dev.parent); |
290 | struct stmpe_touch *ts; |
291 | struct input_dev *idev; |
292 | int error; |
293 | int ts_irq; |
294 | |
295 | ts_irq = platform_get_irq_byname(pdev, "FIFO_TH" ); |
296 | if (ts_irq < 0) |
297 | return ts_irq; |
298 | |
299 | ts = devm_kzalloc(dev: &pdev->dev, size: sizeof(*ts), GFP_KERNEL); |
300 | if (!ts) |
301 | return -ENOMEM; |
302 | |
303 | idev = devm_input_allocate_device(&pdev->dev); |
304 | if (!idev) |
305 | return -ENOMEM; |
306 | |
307 | platform_set_drvdata(pdev, data: ts); |
308 | ts->stmpe = stmpe; |
309 | ts->idev = idev; |
310 | ts->dev = &pdev->dev; |
311 | |
312 | stmpe_ts_get_platform_info(pdev, ts); |
313 | |
314 | INIT_DELAYED_WORK(&ts->work, stmpe_work); |
315 | |
316 | error = devm_request_threaded_irq(dev: &pdev->dev, irq: ts_irq, |
317 | NULL, thread_fn: stmpe_ts_handler, |
318 | IRQF_ONESHOT, STMPE_TS_NAME, dev_id: ts); |
319 | if (error) { |
320 | dev_err(&pdev->dev, "Failed to request IRQ %d\n" , ts_irq); |
321 | return error; |
322 | } |
323 | |
324 | error = stmpe_init_hw(ts); |
325 | if (error) |
326 | return error; |
327 | |
328 | idev->name = STMPE_TS_NAME; |
329 | idev->phys = STMPE_TS_NAME"/input0" ; |
330 | idev->id.bustype = BUS_I2C; |
331 | |
332 | idev->open = stmpe_ts_open; |
333 | idev->close = stmpe_ts_close; |
334 | |
335 | input_set_drvdata(dev: idev, data: ts); |
336 | |
337 | input_set_capability(dev: idev, EV_KEY, BTN_TOUCH); |
338 | input_set_abs_params(dev: idev, ABS_X, min: 0, XY_MASK, fuzz: 0, flat: 0); |
339 | input_set_abs_params(dev: idev, ABS_Y, min: 0, XY_MASK, fuzz: 0, flat: 0); |
340 | input_set_abs_params(dev: idev, ABS_PRESSURE, min: 0x0, max: 0xff, fuzz: 0, flat: 0); |
341 | |
342 | touchscreen_parse_properties(input: idev, multitouch: false, prop: &ts->prop); |
343 | |
344 | error = input_register_device(idev); |
345 | if (error) { |
346 | dev_err(&pdev->dev, "Could not register input device\n" ); |
347 | return error; |
348 | } |
349 | |
350 | return 0; |
351 | } |
352 | |
353 | static int stmpe_ts_remove(struct platform_device *pdev) |
354 | { |
355 | struct stmpe_touch *ts = platform_get_drvdata(pdev); |
356 | |
357 | stmpe_disable(stmpe: ts->stmpe, blocks: STMPE_BLOCK_TOUCHSCREEN); |
358 | |
359 | return 0; |
360 | } |
361 | |
362 | static struct platform_driver stmpe_ts_driver = { |
363 | .driver = { |
364 | .name = STMPE_TS_NAME, |
365 | }, |
366 | .probe = stmpe_input_probe, |
367 | .remove = stmpe_ts_remove, |
368 | }; |
369 | module_platform_driver(stmpe_ts_driver); |
370 | |
371 | static const struct of_device_id stmpe_ts_ids[] = { |
372 | { .compatible = "st,stmpe-ts" , }, |
373 | { }, |
374 | }; |
375 | MODULE_DEVICE_TABLE(of, stmpe_ts_ids); |
376 | |
377 | MODULE_AUTHOR("Luotao Fu <l.fu@pengutronix.de>" ); |
378 | MODULE_DESCRIPTION("STMPEXXX touchscreen driver" ); |
379 | MODULE_LICENSE("GPL" ); |
380 | |