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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Samsung S3C24XX touchscreen driver
4 *
5 * Copyright 2004 Arnaud Patard <arnaud.patard@rtp-net.org>
6 * Copyright 2008 Ben Dooks <ben-linux@fluff.org>
7 * Copyright 2009 Simtec Electronics <linux@simtec.co.uk>
8 *
9 * Additional work by Herbert Pötzl <herbert@13thfloor.at> and
10 * Harald Welte <laforge@openmoko.org>
11 */
12
13#include <linux/errno.h>
14#include <linux/kernel.h>
15#include <linux/module.h>
16#include <linux/gpio.h>
17#include <linux/input.h>
18#include <linux/delay.h>
19#include <linux/interrupt.h>
20#include <linux/platform_device.h>
21#include <linux/clk.h>
22#include <linux/io.h>
23
24#include <plat/adc.h>
25#include <plat/regs-adc.h>
26#include <linux/platform_data/touchscreen-s3c2410.h>
27
28#define TSC_SLEEP (S3C2410_ADCTSC_PULL_UP_DISABLE | S3C2410_ADCTSC_XY_PST(0))
29
30#define INT_DOWN (0)
31#define INT_UP (1 << 8)
32
33#define WAIT4INT (S3C2410_ADCTSC_YM_SEN | \
34 S3C2410_ADCTSC_YP_SEN | \
35 S3C2410_ADCTSC_XP_SEN | \
36 S3C2410_ADCTSC_XY_PST(3))
37
38#define AUTOPST (S3C2410_ADCTSC_YM_SEN | \
39 S3C2410_ADCTSC_YP_SEN | \
40 S3C2410_ADCTSC_XP_SEN | \
41 S3C2410_ADCTSC_AUTO_PST | \
42 S3C2410_ADCTSC_XY_PST(0))
43
44#define FEAT_PEN_IRQ (1 << 0) /* HAS ADCCLRINTPNDNUP */
45
46/* Per-touchscreen data. */
47
48/**
49 * struct s3c2410ts - driver touchscreen state.
50 * @client: The ADC client we registered with the core driver.
51 * @dev: The device we are bound to.
52 * @input: The input device we registered with the input subsystem.
53 * @clock: The clock for the adc.
54 * @io: Pointer to the IO base.
55 * @xp: The accumulated X position data.
56 * @yp: The accumulated Y position data.
57 * @irq_tc: The interrupt number for pen up/down interrupt
58 * @count: The number of samples collected.
59 * @shift: The log2 of the maximum count to read in one go.
60 * @features: The features supported by the TSADC MOdule.
61 */
62struct s3c2410ts {
63 struct s3c_adc_client *client;
64 struct device *dev;
65 struct input_dev *input;
66 struct clk *clock;
67 void __iomem *io;
68 unsigned long xp;
69 unsigned long yp;
70 int irq_tc;
71 int count;
72 int shift;
73 int features;
74};
75
76static struct s3c2410ts ts;
77
78/**
79 * get_down - return the down state of the pen
80 * @data0: The data read from ADCDAT0 register.
81 * @data1: The data read from ADCDAT1 register.
82 *
83 * Return non-zero if both readings show that the pen is down.
84 */
85static inline bool get_down(unsigned long data0, unsigned long data1)
86{
87 /* returns true if both data values show stylus down */
88 return (!(data0 & S3C2410_ADCDAT0_UPDOWN) &&
89 !(data1 & S3C2410_ADCDAT0_UPDOWN));
90}
91
92static void touch_timer_fire(struct timer_list *unused)
93{
94 unsigned long data0;
95 unsigned long data1;
96 bool down;
97
98 data0 = readl(ts.io + S3C2410_ADCDAT0);
99 data1 = readl(ts.io + S3C2410_ADCDAT1);
100
101 down = get_down(data0, data1);
102
103 if (down) {
104 if (ts.count == (1 << ts.shift)) {
105 ts.xp >>= ts.shift;
106 ts.yp >>= ts.shift;
107
108 dev_dbg(ts.dev, "%s: X=%lu, Y=%lu, count=%d\n",
109 __func__, ts.xp, ts.yp, ts.count);
110
111 input_report_abs(ts.input, ABS_X, ts.xp);
112 input_report_abs(ts.input, ABS_Y, ts.yp);
113
114 input_report_key(ts.input, BTN_TOUCH, 1);
115 input_sync(ts.input);
116
117 ts.xp = 0;
118 ts.yp = 0;
119 ts.count = 0;
120 }
121
122 s3c_adc_start(ts.client, 0, 1 << ts.shift);
123 } else {
124 ts.xp = 0;
125 ts.yp = 0;
126 ts.count = 0;
127
128 input_report_key(ts.input, BTN_TOUCH, 0);
129 input_sync(ts.input);
130
131 writel(WAIT4INT | INT_DOWN, ts.io + S3C2410_ADCTSC);
132 }
133}
134
135static DEFINE_TIMER(touch_timer, touch_timer_fire);
136
137/**
138 * stylus_irq - touchscreen stylus event interrupt
139 * @irq: The interrupt number
140 * @dev_id: The device ID.
141 *
142 * Called when the IRQ_TC is fired for a pen up or down event.
143 */
144static irqreturn_t stylus_irq(int irq, void *dev_id)
145{
146 unsigned long data0;
147 unsigned long data1;
148 bool down;
149
150 data0 = readl(ts.io + S3C2410_ADCDAT0);
151 data1 = readl(ts.io + S3C2410_ADCDAT1);
152
153 down = get_down(data0, data1);
154
155 /* TODO we should never get an interrupt with down set while
156 * the timer is running, but maybe we ought to verify that the
157 * timer isn't running anyways. */
158
159 if (down)
160 s3c_adc_start(ts.client, 0, 1 << ts.shift);
161 else
162 dev_dbg(ts.dev, "%s: count=%d\n", __func__, ts.count);
163
164 if (ts.features & FEAT_PEN_IRQ) {
165 /* Clear pen down/up interrupt */
166 writel(0x0, ts.io + S3C64XX_ADCCLRINTPNDNUP);
167 }
168
169 return IRQ_HANDLED;
170}
171
172/**
173 * s3c24xx_ts_conversion - ADC conversion callback
174 * @client: The client that was registered with the ADC core.
175 * @data0: The reading from ADCDAT0.
176 * @data1: The reading from ADCDAT1.
177 * @left: The number of samples left.
178 *
179 * Called when a conversion has finished.
180 */
181static void s3c24xx_ts_conversion(struct s3c_adc_client *client,
182 unsigned data0, unsigned data1,
183 unsigned *left)
184{
185 dev_dbg(ts.dev, "%s: %d,%d\n", __func__, data0, data1);
186
187 ts.xp += data0;
188 ts.yp += data1;
189
190 ts.count++;
191
192 /* From tests, it seems that it is unlikely to get a pen-up
193 * event during the conversion process which means we can
194 * ignore any pen-up events with less than the requisite
195 * count done.
196 *
197 * In several thousand conversions, no pen-ups where detected
198 * before count completed.
199 */
200}
201
202/**
203 * s3c24xx_ts_select - ADC selection callback.
204 * @client: The client that was registered with the ADC core.
205 * @select: The reason for select.
206 *
207 * Called when the ADC core selects (or deslects) us as a client.
208 */
209static void s3c24xx_ts_select(struct s3c_adc_client *client, unsigned select)
210{
211 if (select) {
212 writel(S3C2410_ADCTSC_PULL_UP_DISABLE | AUTOPST,
213 ts.io + S3C2410_ADCTSC);
214 } else {
215 mod_timer(&touch_timer, jiffies+1);
216 writel(WAIT4INT | INT_UP, ts.io + S3C2410_ADCTSC);
217 }
218}
219
220/**
221 * s3c2410ts_probe - device core probe entry point
222 * @pdev: The device we are being bound to.
223 *
224 * Initialise, find and allocate any resources we need to run and then
225 * register with the ADC and input systems.
226 */
227static int s3c2410ts_probe(struct platform_device *pdev)
228{
229 struct s3c2410_ts_mach_info *info;
230 struct device *dev = &pdev->dev;
231 struct input_dev *input_dev;
232 struct resource *res;
233 int ret = -EINVAL;
234
235 /* Initialise input stuff */
236 memset(&ts, 0, sizeof(struct s3c2410ts));
237
238 ts.dev = dev;
239
240 info = dev_get_platdata(dev);
241 if (!info) {
242 dev_err(dev, "no platform data, cannot attach\n");
243 return -EINVAL;
244 }
245
246 dev_dbg(dev, "initialising touchscreen\n");
247
248 ts.clock = clk_get(dev, "adc");
249 if (IS_ERR(ts.clock)) {
250 dev_err(dev, "cannot get adc clock source\n");
251 return -ENOENT;
252 }
253
254 ret = clk_prepare_enable(ts.clock);
255 if (ret) {
256 dev_err(dev, "Failed! to enabled clocks\n");
257 goto err_clk_get;
258 }
259 dev_dbg(dev, "got and enabled clocks\n");
260
261 ts.irq_tc = ret = platform_get_irq(pdev, 0);
262 if (ret < 0) {
263 dev_err(dev, "no resource for interrupt\n");
264 goto err_clk;
265 }
266
267 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
268 if (!res) {
269 dev_err(dev, "no resource for registers\n");
270 ret = -ENOENT;
271 goto err_clk;
272 }
273
274 ts.io = ioremap(res->start, resource_size(res));
275 if (ts.io == NULL) {
276 dev_err(dev, "cannot map registers\n");
277 ret = -ENOMEM;
278 goto err_clk;
279 }
280
281 /* inititalise the gpio */
282 if (info->cfg_gpio)
283 info->cfg_gpio(to_platform_device(ts.dev));
284
285 ts.client = s3c_adc_register(pdev, s3c24xx_ts_select,
286 s3c24xx_ts_conversion, 1);
287 if (IS_ERR(ts.client)) {
288 dev_err(dev, "failed to register adc client\n");
289 ret = PTR_ERR(ts.client);
290 goto err_iomap;
291 }
292
293 /* Initialise registers */
294 if ((info->delay & 0xffff) > 0)
295 writel(info->delay & 0xffff, ts.io + S3C2410_ADCDLY);
296
297 writel(WAIT4INT | INT_DOWN, ts.io + S3C2410_ADCTSC);
298
299 input_dev = input_allocate_device();
300 if (!input_dev) {
301 dev_err(dev, "Unable to allocate the input device !!\n");
302 ret = -ENOMEM;
303 goto err_iomap;
304 }
305
306 ts.input = input_dev;
307 ts.input->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
308 ts.input->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
309 input_set_abs_params(ts.input, ABS_X, 0, 0x3FF, 0, 0);
310 input_set_abs_params(ts.input, ABS_Y, 0, 0x3FF, 0, 0);
311
312 ts.input->name = "S3C24XX TouchScreen";
313 ts.input->id.bustype = BUS_HOST;
314 ts.input->id.vendor = 0xDEAD;
315 ts.input->id.product = 0xBEEF;
316 ts.input->id.version = 0x0102;
317
318 ts.shift = info->oversampling_shift;
319 ts.features = platform_get_device_id(pdev)->driver_data;
320
321 ret = request_irq(ts.irq_tc, stylus_irq, 0,
322 "s3c2410_ts_pen", ts.input);
323 if (ret) {
324 dev_err(dev, "cannot get TC interrupt\n");
325 goto err_inputdev;
326 }
327
328 dev_info(dev, "driver attached, registering input device\n");
329
330 /* All went ok, so register to the input system */
331 ret = input_register_device(ts.input);
332 if (ret < 0) {
333 dev_err(dev, "failed to register input device\n");
334 ret = -EIO;
335 goto err_tcirq;
336 }
337
338 return 0;
339
340 err_tcirq:
341 free_irq(ts.irq_tc, ts.input);
342 err_inputdev:
343 input_free_device(ts.input);
344 err_iomap:
345 iounmap(ts.io);
346 err_clk:
347 clk_disable_unprepare(ts.clock);
348 del_timer_sync(&touch_timer);
349 err_clk_get:
350 clk_put(ts.clock);
351 return ret;
352}
353
354/**
355 * s3c2410ts_remove - device core removal entry point
356 * @pdev: The device we are being removed from.
357 *
358 * Free up our state ready to be removed.
359 */
360static int s3c2410ts_remove(struct platform_device *pdev)
361{
362 free_irq(ts.irq_tc, ts.input);
363 del_timer_sync(&touch_timer);
364
365 clk_disable_unprepare(ts.clock);
366 clk_put(ts.clock);
367
368 input_unregister_device(ts.input);
369 iounmap(ts.io);
370
371 return 0;
372}
373
374#ifdef CONFIG_PM
375static int s3c2410ts_suspend(struct device *dev)
376{
377 writel(TSC_SLEEP, ts.io + S3C2410_ADCTSC);
378 disable_irq(ts.irq_tc);
379 clk_disable(ts.clock);
380
381 return 0;
382}
383
384static int s3c2410ts_resume(struct device *dev)
385{
386 struct platform_device *pdev = to_platform_device(dev);
387 struct s3c2410_ts_mach_info *info = dev_get_platdata(&pdev->dev);
388
389 clk_enable(ts.clock);
390 enable_irq(ts.irq_tc);
391
392 /* Initialise registers */
393 if ((info->delay & 0xffff) > 0)
394 writel(info->delay & 0xffff, ts.io + S3C2410_ADCDLY);
395
396 writel(WAIT4INT | INT_DOWN, ts.io + S3C2410_ADCTSC);
397
398 return 0;
399}
400
401static const struct dev_pm_ops s3c_ts_pmops = {
402 .suspend = s3c2410ts_suspend,
403 .resume = s3c2410ts_resume,
404};
405#endif
406
407static const struct platform_device_id s3cts_driver_ids[] = {
408 { "s3c2410-ts", 0 },
409 { "s3c2440-ts", 0 },
410 { "s3c64xx-ts", FEAT_PEN_IRQ },
411 { }
412};
413MODULE_DEVICE_TABLE(platform, s3cts_driver_ids);
414
415static struct platform_driver s3c_ts_driver = {
416 .driver = {
417 .name = "samsung-ts",
418#ifdef CONFIG_PM
419 .pm = &s3c_ts_pmops,
420#endif
421 },
422 .id_table = s3cts_driver_ids,
423 .probe = s3c2410ts_probe,
424 .remove = s3c2410ts_remove,
425};
426module_platform_driver(s3c_ts_driver);
427
428MODULE_AUTHOR("Arnaud Patard <arnaud.patard@rtp-net.org>, "
429 "Ben Dooks <ben@simtec.co.uk>, "
430 "Simtec Electronics <linux@simtec.co.uk>");
431MODULE_DESCRIPTION("S3C24XX Touchscreen driver");
432MODULE_LICENSE("GPL v2");