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/init.h>
32 #include <linux/delay.h>
33 #include <linux/interrupt.h>
34 #include <linux/platform_device.h>
35 #include <linux/clk.h>
36 #include <linux/io.h>
37
38 #include <plat/adc.h>
39 #include <plat/regs-adc.h>
40 #include <plat/ts.h>
41
42 #define TSC_SLEEP (S3C2410_ADCTSC_PULL_UP_DISABLE | S3C2410_ADCTSC_XY_PST(0))
43
44 #define INT_DOWN (0)
45 #define INT_UP (1 << 8)
46
47 #define WAIT4INT (S3C2410_ADCTSC_YM_SEN | \
48 S3C2410_ADCTSC_YP_SEN | \
49 S3C2410_ADCTSC_XP_SEN | \
50 S3C2410_ADCTSC_XY_PST(3))
51
52 #define AUTOPST (S3C2410_ADCTSC_YM_SEN | \
53 S3C2410_ADCTSC_YP_SEN | \
54 S3C2410_ADCTSC_XP_SEN | \
55 S3C2410_ADCTSC_AUTO_PST | \
56 S3C2410_ADCTSC_XY_PST(0))
57
58 #define FEAT_PEN_IRQ (1 << 0) /* HAS ADCCLRINTPNDNUP */
59
60 /* Per-touchscreen data. */
61
62 /**
63 * struct s3c2410ts - driver touchscreen state.
64 * @client: The ADC client we registered with the core driver.
65 * @dev: The device we are bound to.
66 * @input: The input device we registered with the input subsystem.
67 * @clock: The clock for the adc.
68 * @io: Pointer to the IO base.
69 * @xp: The accumulated X position data.
70 * @yp: The accumulated Y position data.
71 * @irq_tc: The interrupt number for pen up/down interrupt
72 * @count: The number of samples collected.
73 * @shift: The log2 of the maximum count to read in one go.
74 * @features: The features supported by the TSADC MOdule.
75 */
76 struct s3c2410ts {
77 struct s3c_adc_client *client;
78 struct device *dev;
79 struct input_dev *input;
80 struct clk *clock;
81 void __iomem *io;
82 unsigned long xp;
83 unsigned long yp;
84 int irq_tc;
85 int count;
86 int shift;
87 int features;
88 };
89
90 static struct s3c2410ts ts;
91
92 /**
93 * get_down - return the down state of the pen
94 * @data0: The data read from ADCDAT0 register.
95 * @data1: The data read from ADCDAT1 register.
96 *
97 * Return non-zero if both readings show that the pen is down.
98 */
get_down(unsigned long data0,unsigned long data1)99 static inline bool get_down(unsigned long data0, unsigned long data1)
100 {
101 /* returns true if both data values show stylus down */
102 return (!(data0 & S3C2410_ADCDAT0_UPDOWN) &&
103 !(data1 & S3C2410_ADCDAT0_UPDOWN));
104 }
105
touch_timer_fire(unsigned long data)106 static void touch_timer_fire(unsigned long data)
107 {
108 unsigned long data0;
109 unsigned long data1;
110 bool down;
111
112 data0 = readl(ts.io + S3C2410_ADCDAT0);
113 data1 = readl(ts.io + S3C2410_ADCDAT1);
114
115 down = get_down(data0, data1);
116
117 if (down) {
118 if (ts.count == (1 << ts.shift)) {
119 ts.xp >>= ts.shift;
120 ts.yp >>= ts.shift;
121
122 dev_dbg(ts.dev, "%s: X=%lu, Y=%lu, count=%d\n",
123 __func__, ts.xp, ts.yp, ts.count);
124
125 input_report_abs(ts.input, ABS_X, ts.xp);
126 input_report_abs(ts.input, ABS_Y, ts.yp);
127
128 input_report_key(ts.input, BTN_TOUCH, 1);
129 input_sync(ts.input);
130
131 ts.xp = 0;
132 ts.yp = 0;
133 ts.count = 0;
134 }
135
136 s3c_adc_start(ts.client, 0, 1 << ts.shift);
137 } else {
138 ts.xp = 0;
139 ts.yp = 0;
140 ts.count = 0;
141
142 input_report_key(ts.input, BTN_TOUCH, 0);
143 input_sync(ts.input);
144
145 writel(WAIT4INT | INT_DOWN, ts.io + S3C2410_ADCTSC);
146 }
147 }
148
149 static DEFINE_TIMER(touch_timer, touch_timer_fire, 0, 0);
150
151 /**
152 * stylus_irq - touchscreen stylus event interrupt
153 * @irq: The interrupt number
154 * @dev_id: The device ID.
155 *
156 * Called when the IRQ_TC is fired for a pen up or down event.
157 */
stylus_irq(int irq,void * dev_id)158 static irqreturn_t stylus_irq(int irq, void *dev_id)
159 {
160 unsigned long data0;
161 unsigned long data1;
162 bool down;
163
164 data0 = readl(ts.io + S3C2410_ADCDAT0);
165 data1 = readl(ts.io + S3C2410_ADCDAT1);
166
167 down = get_down(data0, data1);
168
169 /* TODO we should never get an interrupt with down set while
170 * the timer is running, but maybe we ought to verify that the
171 * timer isn't running anyways. */
172
173 if (down)
174 s3c_adc_start(ts.client, 0, 1 << ts.shift);
175 else
176 dev_dbg(ts.dev, "%s: count=%d\n", __func__, ts.count);
177
178 if (ts.features & FEAT_PEN_IRQ) {
179 /* Clear pen down/up interrupt */
180 writel(0x0, ts.io + S3C64XX_ADCCLRINTPNDNUP);
181 }
182
183 return IRQ_HANDLED;
184 }
185
186 /**
187 * s3c24xx_ts_conversion - ADC conversion callback
188 * @client: The client that was registered with the ADC core.
189 * @data0: The reading from ADCDAT0.
190 * @data1: The reading from ADCDAT1.
191 * @left: The number of samples left.
192 *
193 * Called when a conversion has finished.
194 */
s3c24xx_ts_conversion(struct s3c_adc_client * client,unsigned data0,unsigned data1,unsigned * left)195 static void s3c24xx_ts_conversion(struct s3c_adc_client *client,
196 unsigned data0, unsigned data1,
197 unsigned *left)
198 {
199 dev_dbg(ts.dev, "%s: %d,%d\n", __func__, data0, data1);
200
201 ts.xp += data0;
202 ts.yp += data1;
203
204 ts.count++;
205
206 /* From tests, it seems that it is unlikely to get a pen-up
207 * event during the conversion process which means we can
208 * ignore any pen-up events with less than the requisite
209 * count done.
210 *
211 * In several thousand conversions, no pen-ups where detected
212 * before count completed.
213 */
214 }
215
216 /**
217 * s3c24xx_ts_select - ADC selection callback.
218 * @client: The client that was registered with the ADC core.
219 * @select: The reason for select.
220 *
221 * Called when the ADC core selects (or deslects) us as a client.
222 */
s3c24xx_ts_select(struct s3c_adc_client * client,unsigned select)223 static void s3c24xx_ts_select(struct s3c_adc_client *client, unsigned select)
224 {
225 if (select) {
226 writel(S3C2410_ADCTSC_PULL_UP_DISABLE | AUTOPST,
227 ts.io + S3C2410_ADCTSC);
228 } else {
229 mod_timer(&touch_timer, jiffies+1);
230 writel(WAIT4INT | INT_UP, ts.io + S3C2410_ADCTSC);
231 }
232 }
233
234 /**
235 * s3c2410ts_probe - device core probe entry point
236 * @pdev: The device we are being bound to.
237 *
238 * Initialise, find and allocate any resources we need to run and then
239 * register with the ADC and input systems.
240 */
s3c2410ts_probe(struct platform_device * pdev)241 static int __devinit s3c2410ts_probe(struct platform_device *pdev)
242 {
243 struct s3c2410_ts_mach_info *info;
244 struct device *dev = &pdev->dev;
245 struct input_dev *input_dev;
246 struct resource *res;
247 int ret = -EINVAL;
248
249 /* Initialise input stuff */
250 memset(&ts, 0, sizeof(struct s3c2410ts));
251
252 ts.dev = dev;
253
254 info = pdev->dev.platform_data;
255 if (!info) {
256 dev_err(dev, "no platform data, cannot attach\n");
257 return -EINVAL;
258 }
259
260 dev_dbg(dev, "initialising touchscreen\n");
261
262 ts.clock = clk_get(dev, "adc");
263 if (IS_ERR(ts.clock)) {
264 dev_err(dev, "cannot get adc clock source\n");
265 return -ENOENT;
266 }
267
268 clk_enable(ts.clock);
269 dev_dbg(dev, "got and enabled clocks\n");
270
271 ts.irq_tc = ret = platform_get_irq(pdev, 0);
272 if (ret < 0) {
273 dev_err(dev, "no resource for interrupt\n");
274 goto err_clk;
275 }
276
277 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
278 if (!res) {
279 dev_err(dev, "no resource for registers\n");
280 ret = -ENOENT;
281 goto err_clk;
282 }
283
284 ts.io = ioremap(res->start, resource_size(res));
285 if (ts.io == NULL) {
286 dev_err(dev, "cannot map registers\n");
287 ret = -ENOMEM;
288 goto err_clk;
289 }
290
291 /* inititalise the gpio */
292 if (info->cfg_gpio)
293 info->cfg_gpio(to_platform_device(ts.dev));
294
295 ts.client = s3c_adc_register(pdev, s3c24xx_ts_select,
296 s3c24xx_ts_conversion, 1);
297 if (IS_ERR(ts.client)) {
298 dev_err(dev, "failed to register adc client\n");
299 ret = PTR_ERR(ts.client);
300 goto err_iomap;
301 }
302
303 /* Initialise registers */
304 if ((info->delay & 0xffff) > 0)
305 writel(info->delay & 0xffff, ts.io + S3C2410_ADCDLY);
306
307 writel(WAIT4INT | INT_DOWN, ts.io + S3C2410_ADCTSC);
308
309 input_dev = input_allocate_device();
310 if (!input_dev) {
311 dev_err(dev, "Unable to allocate the input device !!\n");
312 ret = -ENOMEM;
313 goto err_iomap;
314 }
315
316 ts.input = input_dev;
317 ts.input->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
318 ts.input->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
319 input_set_abs_params(ts.input, ABS_X, 0, 0x3FF, 0, 0);
320 input_set_abs_params(ts.input, ABS_Y, 0, 0x3FF, 0, 0);
321
322 ts.input->name = "S3C24XX TouchScreen";
323 ts.input->id.bustype = BUS_HOST;
324 ts.input->id.vendor = 0xDEAD;
325 ts.input->id.product = 0xBEEF;
326 ts.input->id.version = 0x0102;
327
328 ts.shift = info->oversampling_shift;
329 ts.features = platform_get_device_id(pdev)->driver_data;
330
331 ret = request_irq(ts.irq_tc, stylus_irq, 0,
332 "s3c2410_ts_pen", ts.input);
333 if (ret) {
334 dev_err(dev, "cannot get TC interrupt\n");
335 goto err_inputdev;
336 }
337
338 dev_info(dev, "driver attached, registering input device\n");
339
340 /* All went ok, so register to the input system */
341 ret = input_register_device(ts.input);
342 if (ret < 0) {
343 dev_err(dev, "failed to register input device\n");
344 ret = -EIO;
345 goto err_tcirq;
346 }
347
348 return 0;
349
350 err_tcirq:
351 free_irq(ts.irq_tc, ts.input);
352 err_inputdev:
353 input_free_device(ts.input);
354 err_iomap:
355 iounmap(ts.io);
356 err_clk:
357 del_timer_sync(&touch_timer);
358 clk_put(ts.clock);
359 return ret;
360 }
361
362 /**
363 * s3c2410ts_remove - device core removal entry point
364 * @pdev: The device we are being removed from.
365 *
366 * Free up our state ready to be removed.
367 */
s3c2410ts_remove(struct platform_device * pdev)368 static int __devexit s3c2410ts_remove(struct platform_device *pdev)
369 {
370 free_irq(ts.irq_tc, ts.input);
371 del_timer_sync(&touch_timer);
372
373 clk_disable(ts.clock);
374 clk_put(ts.clock);
375
376 input_unregister_device(ts.input);
377 iounmap(ts.io);
378
379 return 0;
380 }
381
382 #ifdef CONFIG_PM
s3c2410ts_suspend(struct device * dev)383 static int s3c2410ts_suspend(struct device *dev)
384 {
385 writel(TSC_SLEEP, ts.io + S3C2410_ADCTSC);
386 disable_irq(ts.irq_tc);
387 clk_disable(ts.clock);
388
389 return 0;
390 }
391
s3c2410ts_resume(struct device * dev)392 static int s3c2410ts_resume(struct device *dev)
393 {
394 struct platform_device *pdev = to_platform_device(dev);
395 struct s3c2410_ts_mach_info *info = pdev->dev.platform_data;
396
397 clk_enable(ts.clock);
398 enable_irq(ts.irq_tc);
399
400 /* Initialise registers */
401 if ((info->delay & 0xffff) > 0)
402 writel(info->delay & 0xffff, ts.io + S3C2410_ADCDLY);
403
404 writel(WAIT4INT | INT_DOWN, ts.io + S3C2410_ADCTSC);
405
406 return 0;
407 }
408
409 static struct dev_pm_ops s3c_ts_pmops = {
410 .suspend = s3c2410ts_suspend,
411 .resume = s3c2410ts_resume,
412 };
413 #endif
414
415 static struct platform_device_id s3cts_driver_ids[] = {
416 { "s3c2410-ts", 0 },
417 { "s3c2440-ts", 0 },
418 { "s3c64xx-ts", FEAT_PEN_IRQ },
419 { }
420 };
421 MODULE_DEVICE_TABLE(platform, s3cts_driver_ids);
422
423 static struct platform_driver s3c_ts_driver = {
424 .driver = {
425 .name = "samsung-ts",
426 .owner = THIS_MODULE,
427 #ifdef CONFIG_PM
428 .pm = &s3c_ts_pmops,
429 #endif
430 },
431 .id_table = s3cts_driver_ids,
432 .probe = s3c2410ts_probe,
433 .remove = __devexit_p(s3c2410ts_remove),
434 };
435 module_platform_driver(s3c_ts_driver);
436
437 MODULE_AUTHOR("Arnaud Patard <arnaud.patard@rtp-net.org>, "
438 "Ben Dooks <ben@simtec.co.uk>, "
439 "Simtec Electronics <linux@simtec.co.uk>");
440 MODULE_DESCRIPTION("S3C24XX Touchscreen driver");
441 MODULE_LICENSE("GPL v2");
442