1 /*
2 * Samsung S3C24XX touchscreen driver
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the term of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
17 *
18 * Copyright 2004 Arnaud Patard <arnaud.patard@rtp-net.org>
19 * Copyright 2008 Ben Dooks <ben-linux@fluff.org>
20 * Copyright 2009 Simtec Electronics <linux@simtec.co.uk>
21 *
22 * Additional work by Herbert Pötzl <herbert@13thfloor.at> and
23 * Harald Welte <laforge@openmoko.org>
24 */
25
26 #include <linux/errno.h>
27 #include <linux/kernel.h>
28 #include <linux/module.h>
29 #include <linux/gpio.h>
30 #include <linux/input.h>
31 #include <linux/delay.h>
32 #include <linux/interrupt.h>
33 #include <linux/platform_device.h>
34 #include <linux/clk.h>
35 #include <linux/io.h>
36
37 #include <plat/adc.h>
38 #include <plat/regs-adc.h>
39 #include <linux/platform_data/touchscreen-s3c2410.h>
40
41 #define TSC_SLEEP (S3C2410_ADCTSC_PULL_UP_DISABLE | S3C2410_ADCTSC_XY_PST(0))
42
43 #define INT_DOWN (0)
44 #define INT_UP (1 << 8)
45
46 #define WAIT4INT (S3C2410_ADCTSC_YM_SEN | \
47 S3C2410_ADCTSC_YP_SEN | \
48 S3C2410_ADCTSC_XP_SEN | \
49 S3C2410_ADCTSC_XY_PST(3))
50
51 #define AUTOPST (S3C2410_ADCTSC_YM_SEN | \
52 S3C2410_ADCTSC_YP_SEN | \
53 S3C2410_ADCTSC_XP_SEN | \
54 S3C2410_ADCTSC_AUTO_PST | \
55 S3C2410_ADCTSC_XY_PST(0))
56
57 #define FEAT_PEN_IRQ (1 << 0) /* HAS ADCCLRINTPNDNUP */
58
59 /* Per-touchscreen data. */
60
61 /**
62 * struct s3c2410ts - driver touchscreen state.
63 * @client: The ADC client we registered with the core driver.
64 * @dev: The device we are bound to.
65 * @input: The input device we registered with the input subsystem.
66 * @clock: The clock for the adc.
67 * @io: Pointer to the IO base.
68 * @xp: The accumulated X position data.
69 * @yp: The accumulated Y position data.
70 * @irq_tc: The interrupt number for pen up/down interrupt
71 * @count: The number of samples collected.
72 * @shift: The log2 of the maximum count to read in one go.
73 * @features: The features supported by the TSADC MOdule.
74 */
75 struct s3c2410ts {
76 struct s3c_adc_client *client;
77 struct device *dev;
78 struct input_dev *input;
79 struct clk *clock;
80 void __iomem *io;
81 unsigned long xp;
82 unsigned long yp;
83 int irq_tc;
84 int count;
85 int shift;
86 int features;
87 };
88
89 static struct s3c2410ts ts;
90
91 /**
92 * get_down - return the down state of the pen
93 * @data0: The data read from ADCDAT0 register.
94 * @data1: The data read from ADCDAT1 register.
95 *
96 * Return non-zero if both readings show that the pen is down.
97 */
get_down(unsigned long data0,unsigned long data1)98 static inline bool get_down(unsigned long data0, unsigned long data1)
99 {
100 /* returns true if both data values show stylus down */
101 return (!(data0 & S3C2410_ADCDAT0_UPDOWN) &&
102 !(data1 & S3C2410_ADCDAT0_UPDOWN));
103 }
104
touch_timer_fire(unsigned long data)105 static void touch_timer_fire(unsigned long data)
106 {
107 unsigned long data0;
108 unsigned long data1;
109 bool down;
110
111 data0 = readl(ts.io + S3C2410_ADCDAT0);
112 data1 = readl(ts.io + S3C2410_ADCDAT1);
113
114 down = get_down(data0, data1);
115
116 if (down) {
117 if (ts.count == (1 << ts.shift)) {
118 ts.xp >>= ts.shift;
119 ts.yp >>= ts.shift;
120
121 dev_dbg(ts.dev, "%s: X=%lu, Y=%lu, count=%d\n",
122 __func__, ts.xp, ts.yp, ts.count);
123
124 input_report_abs(ts.input, ABS_X, ts.xp);
125 input_report_abs(ts.input, ABS_Y, ts.yp);
126
127 input_report_key(ts.input, BTN_TOUCH, 1);
128 input_sync(ts.input);
129
130 ts.xp = 0;
131 ts.yp = 0;
132 ts.count = 0;
133 }
134
135 s3c_adc_start(ts.client, 0, 1 << ts.shift);
136 } else {
137 ts.xp = 0;
138 ts.yp = 0;
139 ts.count = 0;
140
141 input_report_key(ts.input, BTN_TOUCH, 0);
142 input_sync(ts.input);
143
144 writel(WAIT4INT | INT_DOWN, ts.io + S3C2410_ADCTSC);
145 }
146 }
147
148 static DEFINE_TIMER(touch_timer, touch_timer_fire, 0, 0);
149
150 /**
151 * stylus_irq - touchscreen stylus event interrupt
152 * @irq: The interrupt number
153 * @dev_id: The device ID.
154 *
155 * Called when the IRQ_TC is fired for a pen up or down event.
156 */
stylus_irq(int irq,void * dev_id)157 static irqreturn_t stylus_irq(int irq, void *dev_id)
158 {
159 unsigned long data0;
160 unsigned long data1;
161 bool down;
162
163 data0 = readl(ts.io + S3C2410_ADCDAT0);
164 data1 = readl(ts.io + S3C2410_ADCDAT1);
165
166 down = get_down(data0, data1);
167
168 /* TODO we should never get an interrupt with down set while
169 * the timer is running, but maybe we ought to verify that the
170 * timer isn't running anyways. */
171
172 if (down)
173 s3c_adc_start(ts.client, 0, 1 << ts.shift);
174 else
175 dev_dbg(ts.dev, "%s: count=%d\n", __func__, ts.count);
176
177 if (ts.features & FEAT_PEN_IRQ) {
178 /* Clear pen down/up interrupt */
179 writel(0x0, ts.io + S3C64XX_ADCCLRINTPNDNUP);
180 }
181
182 return IRQ_HANDLED;
183 }
184
185 /**
186 * s3c24xx_ts_conversion - ADC conversion callback
187 * @client: The client that was registered with the ADC core.
188 * @data0: The reading from ADCDAT0.
189 * @data1: The reading from ADCDAT1.
190 * @left: The number of samples left.
191 *
192 * Called when a conversion has finished.
193 */
s3c24xx_ts_conversion(struct s3c_adc_client * client,unsigned data0,unsigned data1,unsigned * left)194 static void s3c24xx_ts_conversion(struct s3c_adc_client *client,
195 unsigned data0, unsigned data1,
196 unsigned *left)
197 {
198 dev_dbg(ts.dev, "%s: %d,%d\n", __func__, data0, data1);
199
200 ts.xp += data0;
201 ts.yp += data1;
202
203 ts.count++;
204
205 /* From tests, it seems that it is unlikely to get a pen-up
206 * event during the conversion process which means we can
207 * ignore any pen-up events with less than the requisite
208 * count done.
209 *
210 * In several thousand conversions, no pen-ups where detected
211 * before count completed.
212 */
213 }
214
215 /**
216 * s3c24xx_ts_select - ADC selection callback.
217 * @client: The client that was registered with the ADC core.
218 * @select: The reason for select.
219 *
220 * Called when the ADC core selects (or deslects) us as a client.
221 */
s3c24xx_ts_select(struct s3c_adc_client * client,unsigned select)222 static void s3c24xx_ts_select(struct s3c_adc_client *client, unsigned select)
223 {
224 if (select) {
225 writel(S3C2410_ADCTSC_PULL_UP_DISABLE | AUTOPST,
226 ts.io + S3C2410_ADCTSC);
227 } else {
228 mod_timer(&touch_timer, jiffies+1);
229 writel(WAIT4INT | INT_UP, ts.io + S3C2410_ADCTSC);
230 }
231 }
232
233 /**
234 * s3c2410ts_probe - device core probe entry point
235 * @pdev: The device we are being bound to.
236 *
237 * Initialise, find and allocate any resources we need to run and then
238 * register with the ADC and input systems.
239 */
s3c2410ts_probe(struct platform_device * pdev)240 static int s3c2410ts_probe(struct platform_device *pdev)
241 {
242 struct s3c2410_ts_mach_info *info;
243 struct device *dev = &pdev->dev;
244 struct input_dev *input_dev;
245 struct resource *res;
246 int ret = -EINVAL;
247
248 /* Initialise input stuff */
249 memset(&ts, 0, sizeof(struct s3c2410ts));
250
251 ts.dev = dev;
252
253 info = dev_get_platdata(&pdev->dev);
254 if (!info) {
255 dev_err(dev, "no platform data, cannot attach\n");
256 return -EINVAL;
257 }
258
259 dev_dbg(dev, "initialising touchscreen\n");
260
261 ts.clock = clk_get(dev, "adc");
262 if (IS_ERR(ts.clock)) {
263 dev_err(dev, "cannot get adc clock source\n");
264 return -ENOENT;
265 }
266
267 clk_prepare_enable(ts.clock);
268 dev_dbg(dev, "got and enabled clocks\n");
269
270 ts.irq_tc = ret = platform_get_irq(pdev, 0);
271 if (ret < 0) {
272 dev_err(dev, "no resource for interrupt\n");
273 goto err_clk;
274 }
275
276 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
277 if (!res) {
278 dev_err(dev, "no resource for registers\n");
279 ret = -ENOENT;
280 goto err_clk;
281 }
282
283 ts.io = ioremap(res->start, resource_size(res));
284 if (ts.io == NULL) {
285 dev_err(dev, "cannot map registers\n");
286 ret = -ENOMEM;
287 goto err_clk;
288 }
289
290 /* inititalise the gpio */
291 if (info->cfg_gpio)
292 info->cfg_gpio(to_platform_device(ts.dev));
293
294 ts.client = s3c_adc_register(pdev, s3c24xx_ts_select,
295 s3c24xx_ts_conversion, 1);
296 if (IS_ERR(ts.client)) {
297 dev_err(dev, "failed to register adc client\n");
298 ret = PTR_ERR(ts.client);
299 goto err_iomap;
300 }
301
302 /* Initialise registers */
303 if ((info->delay & 0xffff) > 0)
304 writel(info->delay & 0xffff, ts.io + S3C2410_ADCDLY);
305
306 writel(WAIT4INT | INT_DOWN, ts.io + S3C2410_ADCTSC);
307
308 input_dev = input_allocate_device();
309 if (!input_dev) {
310 dev_err(dev, "Unable to allocate the input device !!\n");
311 ret = -ENOMEM;
312 goto err_iomap;
313 }
314
315 ts.input = input_dev;
316 ts.input->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
317 ts.input->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
318 input_set_abs_params(ts.input, ABS_X, 0, 0x3FF, 0, 0);
319 input_set_abs_params(ts.input, ABS_Y, 0, 0x3FF, 0, 0);
320
321 ts.input->name = "S3C24XX TouchScreen";
322 ts.input->id.bustype = BUS_HOST;
323 ts.input->id.vendor = 0xDEAD;
324 ts.input->id.product = 0xBEEF;
325 ts.input->id.version = 0x0102;
326
327 ts.shift = info->oversampling_shift;
328 ts.features = platform_get_device_id(pdev)->driver_data;
329
330 ret = request_irq(ts.irq_tc, stylus_irq, 0,
331 "s3c2410_ts_pen", ts.input);
332 if (ret) {
333 dev_err(dev, "cannot get TC interrupt\n");
334 goto err_inputdev;
335 }
336
337 dev_info(dev, "driver attached, registering input device\n");
338
339 /* All went ok, so register to the input system */
340 ret = input_register_device(ts.input);
341 if (ret < 0) {
342 dev_err(dev, "failed to register input device\n");
343 ret = -EIO;
344 goto err_tcirq;
345 }
346
347 return 0;
348
349 err_tcirq:
350 free_irq(ts.irq_tc, ts.input);
351 err_inputdev:
352 input_free_device(ts.input);
353 err_iomap:
354 iounmap(ts.io);
355 err_clk:
356 del_timer_sync(&touch_timer);
357 clk_put(ts.clock);
358 return ret;
359 }
360
361 /**
362 * s3c2410ts_remove - device core removal entry point
363 * @pdev: The device we are being removed from.
364 *
365 * Free up our state ready to be removed.
366 */
s3c2410ts_remove(struct platform_device * pdev)367 static int s3c2410ts_remove(struct platform_device *pdev)
368 {
369 free_irq(ts.irq_tc, ts.input);
370 del_timer_sync(&touch_timer);
371
372 clk_disable_unprepare(ts.clock);
373 clk_put(ts.clock);
374
375 input_unregister_device(ts.input);
376 iounmap(ts.io);
377
378 return 0;
379 }
380
381 #ifdef CONFIG_PM
s3c2410ts_suspend(struct device * dev)382 static int s3c2410ts_suspend(struct device *dev)
383 {
384 writel(TSC_SLEEP, ts.io + S3C2410_ADCTSC);
385 disable_irq(ts.irq_tc);
386 clk_disable(ts.clock);
387
388 return 0;
389 }
390
s3c2410ts_resume(struct device * dev)391 static int s3c2410ts_resume(struct device *dev)
392 {
393 struct platform_device *pdev = to_platform_device(dev);
394 struct s3c2410_ts_mach_info *info = dev_get_platdata(&pdev->dev);
395
396 clk_enable(ts.clock);
397 enable_irq(ts.irq_tc);
398
399 /* Initialise registers */
400 if ((info->delay & 0xffff) > 0)
401 writel(info->delay & 0xffff, ts.io + S3C2410_ADCDLY);
402
403 writel(WAIT4INT | INT_DOWN, ts.io + S3C2410_ADCTSC);
404
405 return 0;
406 }
407
408 static const struct dev_pm_ops s3c_ts_pmops = {
409 .suspend = s3c2410ts_suspend,
410 .resume = s3c2410ts_resume,
411 };
412 #endif
413
414 static struct platform_device_id s3cts_driver_ids[] = {
415 { "s3c2410-ts", 0 },
416 { "s3c2440-ts", 0 },
417 { "s3c64xx-ts", FEAT_PEN_IRQ },
418 { }
419 };
420 MODULE_DEVICE_TABLE(platform, s3cts_driver_ids);
421
422 static struct platform_driver s3c_ts_driver = {
423 .driver = {
424 .name = "samsung-ts",
425 .owner = THIS_MODULE,
426 #ifdef CONFIG_PM
427 .pm = &s3c_ts_pmops,
428 #endif
429 },
430 .id_table = s3cts_driver_ids,
431 .probe = s3c2410ts_probe,
432 .remove = s3c2410ts_remove,
433 };
434 module_platform_driver(s3c_ts_driver);
435
436 MODULE_AUTHOR("Arnaud Patard <arnaud.patard@rtp-net.org>, "
437 "Ben Dooks <ben@simtec.co.uk>, "
438 "Simtec Electronics <linux@simtec.co.uk>");
439 MODULE_DESCRIPTION("S3C24XX Touchscreen driver");
440 MODULE_LICENSE("GPL v2");
441