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Linux/drivers/input/touchscreen/stmpe-ts.c

  1 /*
  2  * STMicroelectronics STMPE811 Touchscreen Driver
  3  *
  4  * (C) 2010 Luotao Fu <l.fu@pengutronix.de>
  5  * All rights reserved.
  6  *
  7  *  This program is free software; you can redistribute  it and/or modify it
  8  *  under  the terms of  the GNU General  Public License as published by the
  9  *  Free Software Foundation;  either version 2 of the  License, or (at your
 10  *  option) any later version.
 11  *
 12  */
 13 
 14 #include <linux/kernel.h>
 15 #include <linux/module.h>
 16 #include <linux/sched.h>
 17 #include <linux/interrupt.h>
 18 #include <linux/device.h>
 19 #include <linux/of.h>
 20 #include <linux/platform_device.h>
 21 #include <linux/input.h>
 22 #include <linux/slab.h>
 23 #include <linux/delay.h>
 24 #include <linux/i2c.h>
 25 #include <linux/workqueue.h>
 26 
 27 #include <linux/mfd/stmpe.h>
 28 
 29 /* Register layouts and functionalities are identical on all stmpexxx variants
 30  * with touchscreen controller
 31  */
 32 #define STMPE_REG_INT_STA               0x0B
 33 #define STMPE_REG_ADC_CTRL1             0x20
 34 #define STMPE_REG_ADC_CTRL2             0x21
 35 #define STMPE_REG_TSC_CTRL              0x40
 36 #define STMPE_REG_TSC_CFG               0x41
 37 #define STMPE_REG_FIFO_TH               0x4A
 38 #define STMPE_REG_FIFO_STA              0x4B
 39 #define STMPE_REG_FIFO_SIZE             0x4C
 40 #define STMPE_REG_TSC_DATA_XYZ          0x52
 41 #define STMPE_REG_TSC_FRACTION_Z        0x56
 42 #define STMPE_REG_TSC_I_DRIVE           0x58
 43 
 44 #define OP_MOD_XYZ                      0
 45 
 46 #define STMPE_TSC_CTRL_TSC_EN           (1<<0)
 47 
 48 #define STMPE_FIFO_STA_RESET            (1<<0)
 49 
 50 #define STMPE_IRQ_TOUCH_DET             0
 51 
 52 #define SAMPLE_TIME(x)                  ((x & 0xf) << 4)
 53 #define MOD_12B(x)                      ((x & 0x1) << 3)
 54 #define REF_SEL(x)                      ((x & 0x1) << 1)
 55 #define ADC_FREQ(x)                     (x & 0x3)
 56 #define AVE_CTRL(x)                     ((x & 0x3) << 6)
 57 #define DET_DELAY(x)                    ((x & 0x7) << 3)
 58 #define SETTLING(x)                     (x & 0x7)
 59 #define FRACTION_Z(x)                   (x & 0x7)
 60 #define I_DRIVE(x)                      (x & 0x1)
 61 #define OP_MODE(x)                      ((x & 0x7) << 1)
 62 
 63 #define STMPE_TS_NAME                   "stmpe-ts"
 64 #define XY_MASK                         0xfff
 65 
 66 struct stmpe_touch {
 67         struct stmpe *stmpe;
 68         struct input_dev *idev;
 69         struct delayed_work work;
 70         struct device *dev;
 71         u8 sample_time;
 72         u8 mod_12b;
 73         u8 ref_sel;
 74         u8 adc_freq;
 75         u8 ave_ctrl;
 76         u8 touch_det_delay;
 77         u8 settling;
 78         u8 fraction_z;
 79         u8 i_drive;
 80 };
 81 
 82 static int __stmpe_reset_fifo(struct stmpe *stmpe)
 83 {
 84         int ret;
 85 
 86         ret = stmpe_set_bits(stmpe, STMPE_REG_FIFO_STA,
 87                         STMPE_FIFO_STA_RESET, STMPE_FIFO_STA_RESET);
 88         if (ret)
 89                 return ret;
 90 
 91         return stmpe_set_bits(stmpe, STMPE_REG_FIFO_STA,
 92                         STMPE_FIFO_STA_RESET, 0);
 93 }
 94 
 95 static void stmpe_work(struct work_struct *work)
 96 {
 97         int int_sta;
 98         u32 timeout = 40;
 99 
100         struct stmpe_touch *ts =
101             container_of(work, struct stmpe_touch, work.work);
102 
103         int_sta = stmpe_reg_read(ts->stmpe, STMPE_REG_INT_STA);
104 
105         /*
106          * touch_det sometimes get desasserted or just get stuck. This appears
107          * to be a silicon bug, We still have to clearify this with the
108          * manufacture. As a workaround We release the key anyway if the
109          * touch_det keeps coming in after 4ms, while the FIFO contains no value
110          * during the whole time.
111          */
112         while ((int_sta & (1 << STMPE_IRQ_TOUCH_DET)) && (timeout > 0)) {
113                 timeout--;
114                 int_sta = stmpe_reg_read(ts->stmpe, STMPE_REG_INT_STA);
115                 udelay(100);
116         }
117 
118         /* reset the FIFO before we report release event */
119         __stmpe_reset_fifo(ts->stmpe);
120 
121         input_report_abs(ts->idev, ABS_PRESSURE, 0);
122         input_report_key(ts->idev, BTN_TOUCH, 0);
123         input_sync(ts->idev);
124 }
125 
126 static irqreturn_t stmpe_ts_handler(int irq, void *data)
127 {
128         u8 data_set[4];
129         int x, y, z;
130         struct stmpe_touch *ts = data;
131 
132         /*
133          * Cancel scheduled polling for release if we have new value
134          * available. Wait if the polling is already running.
135          */
136         cancel_delayed_work_sync(&ts->work);
137 
138         /*
139          * The FIFO sometimes just crashes and stops generating interrupts. This
140          * appears to be a silicon bug. We still have to clearify this with
141          * the manufacture. As a workaround we disable the TSC while we are
142          * collecting data and flush the FIFO after reading
143          */
144         stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL,
145                                 STMPE_TSC_CTRL_TSC_EN, 0);
146 
147         stmpe_block_read(ts->stmpe, STMPE_REG_TSC_DATA_XYZ, 4, data_set);
148 
149         x = (data_set[0] << 4) | (data_set[1] >> 4);
150         y = ((data_set[1] & 0xf) << 8) | data_set[2];
151         z = data_set[3];
152 
153         input_report_abs(ts->idev, ABS_X, x);
154         input_report_abs(ts->idev, ABS_Y, y);
155         input_report_abs(ts->idev, ABS_PRESSURE, z);
156         input_report_key(ts->idev, BTN_TOUCH, 1);
157         input_sync(ts->idev);
158 
159        /* flush the FIFO after we have read out our values. */
160         __stmpe_reset_fifo(ts->stmpe);
161 
162         /* reenable the tsc */
163         stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL,
164                         STMPE_TSC_CTRL_TSC_EN, STMPE_TSC_CTRL_TSC_EN);
165 
166         /* start polling for touch_det to detect release */
167         schedule_delayed_work(&ts->work, HZ / 50);
168 
169         return IRQ_HANDLED;
170 }
171 
172 static int stmpe_init_hw(struct stmpe_touch *ts)
173 {
174         int ret;
175         u8 adc_ctrl1, adc_ctrl1_mask, tsc_cfg, tsc_cfg_mask;
176         struct stmpe *stmpe = ts->stmpe;
177         struct device *dev = ts->dev;
178 
179         ret = stmpe_enable(stmpe, STMPE_BLOCK_TOUCHSCREEN | STMPE_BLOCK_ADC);
180         if (ret) {
181                 dev_err(dev, "Could not enable clock for ADC and TS\n");
182                 return ret;
183         }
184 
185         adc_ctrl1 = SAMPLE_TIME(ts->sample_time) | MOD_12B(ts->mod_12b) |
186                 REF_SEL(ts->ref_sel);
187         adc_ctrl1_mask = SAMPLE_TIME(0xff) | MOD_12B(0xff) | REF_SEL(0xff);
188 
189         ret = stmpe_set_bits(stmpe, STMPE_REG_ADC_CTRL1,
190                         adc_ctrl1_mask, adc_ctrl1);
191         if (ret) {
192                 dev_err(dev, "Could not setup ADC\n");
193                 return ret;
194         }
195 
196         ret = stmpe_set_bits(stmpe, STMPE_REG_ADC_CTRL2,
197                         ADC_FREQ(0xff), ADC_FREQ(ts->adc_freq));
198         if (ret) {
199                 dev_err(dev, "Could not setup ADC\n");
200                 return ret;
201         }
202 
203         tsc_cfg = AVE_CTRL(ts->ave_ctrl) | DET_DELAY(ts->touch_det_delay) |
204                         SETTLING(ts->settling);
205         tsc_cfg_mask = AVE_CTRL(0xff) | DET_DELAY(0xff) | SETTLING(0xff);
206 
207         ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_CFG, tsc_cfg_mask, tsc_cfg);
208         if (ret) {
209                 dev_err(dev, "Could not config touch\n");
210                 return ret;
211         }
212 
213         ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_FRACTION_Z,
214                         FRACTION_Z(0xff), FRACTION_Z(ts->fraction_z));
215         if (ret) {
216                 dev_err(dev, "Could not config touch\n");
217                 return ret;
218         }
219 
220         ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_I_DRIVE,
221                         I_DRIVE(0xff), I_DRIVE(ts->i_drive));
222         if (ret) {
223                 dev_err(dev, "Could not config touch\n");
224                 return ret;
225         }
226 
227         /* set FIFO to 1 for single point reading */
228         ret = stmpe_reg_write(stmpe, STMPE_REG_FIFO_TH, 1);
229         if (ret) {
230                 dev_err(dev, "Could not set FIFO\n");
231                 return ret;
232         }
233 
234         ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_CTRL,
235                         OP_MODE(0xff), OP_MODE(OP_MOD_XYZ));
236         if (ret) {
237                 dev_err(dev, "Could not set mode\n");
238                 return ret;
239         }
240 
241         return 0;
242 }
243 
244 static int stmpe_ts_open(struct input_dev *dev)
245 {
246         struct stmpe_touch *ts = input_get_drvdata(dev);
247         int ret = 0;
248 
249         ret = __stmpe_reset_fifo(ts->stmpe);
250         if (ret)
251                 return ret;
252 
253         return stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL,
254                         STMPE_TSC_CTRL_TSC_EN, STMPE_TSC_CTRL_TSC_EN);
255 }
256 
257 static void stmpe_ts_close(struct input_dev *dev)
258 {
259         struct stmpe_touch *ts = input_get_drvdata(dev);
260 
261         cancel_delayed_work_sync(&ts->work);
262 
263         stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL,
264                         STMPE_TSC_CTRL_TSC_EN, 0);
265 }
266 
267 static void stmpe_ts_get_platform_info(struct platform_device *pdev,
268                                         struct stmpe_touch *ts)
269 {
270         struct stmpe *stmpe = dev_get_drvdata(pdev->dev.parent);
271         struct device_node *np = pdev->dev.of_node;
272         struct stmpe_ts_platform_data *ts_pdata = NULL;
273 
274         ts->stmpe = stmpe;
275 
276         if (stmpe->pdata && stmpe->pdata->ts) {
277                 ts_pdata = stmpe->pdata->ts;
278 
279                 ts->sample_time = ts_pdata->sample_time;
280                 ts->mod_12b = ts_pdata->mod_12b;
281                 ts->ref_sel = ts_pdata->ref_sel;
282                 ts->adc_freq = ts_pdata->adc_freq;
283                 ts->ave_ctrl = ts_pdata->ave_ctrl;
284                 ts->touch_det_delay = ts_pdata->touch_det_delay;
285                 ts->settling = ts_pdata->settling;
286                 ts->fraction_z = ts_pdata->fraction_z;
287                 ts->i_drive = ts_pdata->i_drive;
288         } else if (np) {
289                 u32 val;
290 
291                 if (!of_property_read_u32(np, "st,sample-time", &val))
292                         ts->sample_time = val;
293                 if (!of_property_read_u32(np, "st,mod-12b", &val))
294                         ts->mod_12b = val;
295                 if (!of_property_read_u32(np, "st,ref-sel", &val))
296                         ts->ref_sel = val;
297                 if (!of_property_read_u32(np, "st,adc-freq", &val))
298                         ts->adc_freq = val;
299                 if (!of_property_read_u32(np, "st,ave-ctrl", &val))
300                         ts->ave_ctrl = val;
301                 if (!of_property_read_u32(np, "st,touch-det-delay", &val))
302                         ts->touch_det_delay = val;
303                 if (!of_property_read_u32(np, "st,settling", &val))
304                         ts->settling = val;
305                 if (!of_property_read_u32(np, "st,fraction-z", &val))
306                         ts->fraction_z = val;
307                 if (!of_property_read_u32(np, "st,i-drive", &val))
308                         ts->i_drive = val;
309         }
310 }
311 
312 static int stmpe_input_probe(struct platform_device *pdev)
313 {
314         struct stmpe_touch *ts;
315         struct input_dev *idev;
316         int error;
317         int ts_irq;
318 
319         ts_irq = platform_get_irq_byname(pdev, "FIFO_TH");
320         if (ts_irq < 0)
321                 return ts_irq;
322 
323         ts = devm_kzalloc(&pdev->dev, sizeof(*ts), GFP_KERNEL);
324         if (!ts)
325                 return -ENOMEM;
326 
327         idev = devm_input_allocate_device(&pdev->dev);
328         if (!idev)
329                 return -ENOMEM;
330 
331         platform_set_drvdata(pdev, ts);
332         ts->idev = idev;
333         ts->dev = &pdev->dev;
334 
335         stmpe_ts_get_platform_info(pdev, ts);
336 
337         INIT_DELAYED_WORK(&ts->work, stmpe_work);
338 
339         error = devm_request_threaded_irq(&pdev->dev, ts_irq,
340                                           NULL, stmpe_ts_handler,
341                                           IRQF_ONESHOT, STMPE_TS_NAME, ts);
342         if (error) {
343                 dev_err(&pdev->dev, "Failed to request IRQ %d\n", ts_irq);
344                 return error;
345         }
346 
347         error = stmpe_init_hw(ts);
348         if (error)
349                 return error;
350 
351         idev->name = STMPE_TS_NAME;
352         idev->phys = STMPE_TS_NAME"/input0";
353         idev->id.bustype = BUS_I2C;
354         idev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
355         idev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
356 
357         idev->open = stmpe_ts_open;
358         idev->close = stmpe_ts_close;
359 
360         input_set_drvdata(idev, ts);
361 
362         input_set_abs_params(idev, ABS_X, 0, XY_MASK, 0, 0);
363         input_set_abs_params(idev, ABS_Y, 0, XY_MASK, 0, 0);
364         input_set_abs_params(idev, ABS_PRESSURE, 0x0, 0xff, 0, 0);
365 
366         error = input_register_device(idev);
367         if (error) {
368                 dev_err(&pdev->dev, "Could not register input device\n");
369                 return error;
370         }
371 
372         return 0;
373 }
374 
375 static int stmpe_ts_remove(struct platform_device *pdev)
376 {
377         struct stmpe_touch *ts = platform_get_drvdata(pdev);
378 
379         stmpe_disable(ts->stmpe, STMPE_BLOCK_TOUCHSCREEN);
380 
381         return 0;
382 }
383 
384 static struct platform_driver stmpe_ts_driver = {
385         .driver = {
386                    .name = STMPE_TS_NAME,
387                    .owner = THIS_MODULE,
388                    },
389         .probe = stmpe_input_probe,
390         .remove = stmpe_ts_remove,
391 };
392 module_platform_driver(stmpe_ts_driver);
393 
394 MODULE_AUTHOR("Luotao Fu <l.fu@pengutronix.de>");
395 MODULE_DESCRIPTION("STMPEXXX touchscreen driver");
396 MODULE_LICENSE("GPL");
397 MODULE_ALIAS("platform:" STMPE_TS_NAME);
398 

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