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