2 * STMicroelectronics STMPE811 Touchscreen Driver
4 * (C) 2010 Luotao Fu <l.fu@pengutronix.de>
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.
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/sched.h>
17 #include <linux/interrupt.h>
18 #include <linux/init.h>
19 #include <linux/device.h>
21 #include <linux/platform_device.h>
22 #include <linux/input.h>
23 #include <linux/slab.h>
24 #include <linux/delay.h>
25 #include <linux/i2c.h>
26 #include <linux/workqueue.h>
28 #include <linux/mfd/stmpe.h>
30 /* Register layouts and functionalities are identical on all stmpexxx variants
31 * with touchscreen controller
33 #define STMPE_REG_INT_STA 0x0B
34 #define STMPE_REG_ADC_CTRL1 0x20
35 #define STMPE_REG_ADC_CTRL2 0x21
36 #define STMPE_REG_TSC_CTRL 0x40
37 #define STMPE_REG_TSC_CFG 0x41
38 #define STMPE_REG_FIFO_TH 0x4A
39 #define STMPE_REG_FIFO_STA 0x4B
40 #define STMPE_REG_FIFO_SIZE 0x4C
41 #define STMPE_REG_TSC_DATA_XYZ 0x52
42 #define STMPE_REG_TSC_FRACTION_Z 0x56
43 #define STMPE_REG_TSC_I_DRIVE 0x58
47 #define STMPE_TSC_CTRL_TSC_EN (1<<0)
49 #define STMPE_FIFO_STA_RESET (1<<0)
51 #define STMPE_IRQ_TOUCH_DET 0
53 #define SAMPLE_TIME(x) ((x & 0xf) << 4)
54 #define MOD_12B(x) ((x & 0x1) << 3)
55 #define REF_SEL(x) ((x & 0x1) << 1)
56 #define ADC_FREQ(x) (x & 0x3)
57 #define AVE_CTRL(x) ((x & 0x3) << 6)
58 #define DET_DELAY(x) ((x & 0x7) << 3)
59 #define SETTLING(x) (x & 0x7)
60 #define FRACTION_Z(x) (x & 0x7)
61 #define I_DRIVE(x) (x & 0x1)
62 #define OP_MODE(x) ((x & 0x7) << 1)
64 #define STMPE_TS_NAME "stmpe-ts"
69 struct input_dev *idev;
70 struct delayed_work work;
83 static int __stmpe_reset_fifo(struct stmpe *stmpe)
87 ret = stmpe_set_bits(stmpe, STMPE_REG_FIFO_STA,
88 STMPE_FIFO_STA_RESET, STMPE_FIFO_STA_RESET);
92 return stmpe_set_bits(stmpe, STMPE_REG_FIFO_STA,
93 STMPE_FIFO_STA_RESET, 0);
96 static void stmpe_work(struct work_struct *work)
101 struct stmpe_touch *ts =
102 container_of(work, struct stmpe_touch, work.work);
104 int_sta = stmpe_reg_read(ts->stmpe, STMPE_REG_INT_STA);
107 * touch_det sometimes get desasserted or just get stuck. This appears
108 * to be a silicon bug, We still have to clearify this with the
109 * manufacture. As a workaround We release the key anyway if the
110 * touch_det keeps coming in after 4ms, while the FIFO contains no value
111 * during the whole time.
113 while ((int_sta & (1 << STMPE_IRQ_TOUCH_DET)) && (timeout > 0)) {
115 int_sta = stmpe_reg_read(ts->stmpe, STMPE_REG_INT_STA);
119 /* reset the FIFO before we report release event */
120 __stmpe_reset_fifo(ts->stmpe);
122 input_report_abs(ts->idev, ABS_PRESSURE, 0);
123 input_sync(ts->idev);
126 static irqreturn_t stmpe_ts_handler(int irq, void *data)
130 struct stmpe_touch *ts = data;
133 * Cancel scheduled polling for release if we have new value
134 * available. Wait if the polling is already running.
136 cancel_delayed_work_sync(&ts->work);
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
144 stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL,
145 STMPE_TSC_CTRL_TSC_EN, 0);
147 stmpe_block_read(ts->stmpe, STMPE_REG_TSC_DATA_XYZ, 4, data_set);
149 x = (data_set[0] << 4) | (data_set[1] >> 4);
150 y = ((data_set[1] & 0xf) << 8) | data_set[2];
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_sync(ts->idev);
158 /* flush the FIFO after we have read out our values. */
159 __stmpe_reset_fifo(ts->stmpe);
161 /* reenable the tsc */
162 stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL,
163 STMPE_TSC_CTRL_TSC_EN, STMPE_TSC_CTRL_TSC_EN);
165 /* start polling for touch_det to detect release */
166 schedule_delayed_work(&ts->work, HZ / 50);
171 static int __devinit stmpe_init_hw(struct stmpe_touch *ts)
174 u8 adc_ctrl1, adc_ctrl1_mask, tsc_cfg, tsc_cfg_mask;
175 struct stmpe *stmpe = ts->stmpe;
176 struct device *dev = ts->dev;
178 ret = stmpe_enable(stmpe, STMPE_BLOCK_TOUCHSCREEN | STMPE_BLOCK_ADC);
180 dev_err(dev, "Could not enable clock for ADC and TS\n");
184 adc_ctrl1 = SAMPLE_TIME(ts->sample_time) | MOD_12B(ts->mod_12b) |
185 REF_SEL(ts->ref_sel);
186 adc_ctrl1_mask = SAMPLE_TIME(0xff) | MOD_12B(0xff) | REF_SEL(0xff);
188 ret = stmpe_set_bits(stmpe, STMPE_REG_ADC_CTRL1,
189 adc_ctrl1_mask, adc_ctrl1);
191 dev_err(dev, "Could not setup ADC\n");
195 ret = stmpe_set_bits(stmpe, STMPE_REG_ADC_CTRL2,
196 ADC_FREQ(0xff), ADC_FREQ(ts->adc_freq));
198 dev_err(dev, "Could not setup ADC\n");
202 tsc_cfg = AVE_CTRL(ts->ave_ctrl) | DET_DELAY(ts->touch_det_delay) |
203 SETTLING(ts->settling);
204 tsc_cfg_mask = AVE_CTRL(0xff) | DET_DELAY(0xff) | SETTLING(0xff);
206 ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_CFG, tsc_cfg_mask, tsc_cfg);
208 dev_err(dev, "Could not config touch\n");
212 ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_FRACTION_Z,
213 FRACTION_Z(0xff), FRACTION_Z(ts->fraction_z));
215 dev_err(dev, "Could not config touch\n");
219 ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_I_DRIVE,
220 I_DRIVE(0xff), I_DRIVE(ts->i_drive));
222 dev_err(dev, "Could not config touch\n");
226 /* set FIFO to 1 for single point reading */
227 ret = stmpe_reg_write(stmpe, STMPE_REG_FIFO_TH, 1);
229 dev_err(dev, "Could not set FIFO\n");
233 ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_CTRL,
234 OP_MODE(0xff), OP_MODE(OP_MOD_XYZ));
236 dev_err(dev, "Could not set mode\n");
243 static int stmpe_ts_open(struct input_dev *dev)
245 struct stmpe_touch *ts = input_get_drvdata(dev);
248 ret = __stmpe_reset_fifo(ts->stmpe);
252 return stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL,
253 STMPE_TSC_CTRL_TSC_EN, STMPE_TSC_CTRL_TSC_EN);
256 static void stmpe_ts_close(struct input_dev *dev)
258 struct stmpe_touch *ts = input_get_drvdata(dev);
260 cancel_delayed_work_sync(&ts->work);
262 stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL,
263 STMPE_TSC_CTRL_TSC_EN, 0);
266 static void stmpe_ts_get_platform_info(struct platform_device *pdev,
267 struct stmpe_touch *ts)
269 struct stmpe *stmpe = dev_get_drvdata(pdev->dev.parent);
270 struct device_node *np = pdev->dev.of_node;
271 struct stmpe_ts_platform_data *ts_pdata = NULL;
275 if (stmpe->pdata && stmpe->pdata->ts) {
276 ts_pdata = stmpe->pdata->ts;
278 ts->sample_time = ts_pdata->sample_time;
279 ts->mod_12b = ts_pdata->mod_12b;
280 ts->ref_sel = ts_pdata->ref_sel;
281 ts->adc_freq = ts_pdata->adc_freq;
282 ts->ave_ctrl = ts_pdata->ave_ctrl;
283 ts->touch_det_delay = ts_pdata->touch_det_delay;
284 ts->settling = ts_pdata->settling;
285 ts->fraction_z = ts_pdata->fraction_z;
286 ts->i_drive = ts_pdata->i_drive;
290 if (!of_property_read_u32(np, "st,sample-time", &val))
291 ts->sample_time = val;
292 if (!of_property_read_u32(np, "st,mod-12b", &val))
294 if (!of_property_read_u32(np, "st,ref-sel", &val))
296 if (!of_property_read_u32(np, "st,adc-freq", &val))
298 if (!of_property_read_u32(np, "st,ave-ctrl", &val))
300 if (!of_property_read_u32(np, "st,touch-det-delay", &val))
301 ts->touch_det_delay = val;
302 if (!of_property_read_u32(np, "st,settling", &val))
304 if (!of_property_read_u32(np, "st,fraction-z", &val))
305 ts->fraction_z = val;
306 if (!of_property_read_u32(np, "st,i-drive", &val))
311 static int __devinit stmpe_input_probe(struct platform_device *pdev)
313 struct stmpe_touch *ts;
314 struct input_dev *idev;
318 ts_irq = platform_get_irq_byname(pdev, "FIFO_TH");
322 ts = devm_kzalloc(&pdev->dev, sizeof(*ts), GFP_KERNEL);
326 idev = devm_input_allocate_device(&pdev->dev);
330 platform_set_drvdata(pdev, ts);
332 ts->dev = &pdev->dev;
334 stmpe_ts_get_platform_info(pdev, ts);
336 INIT_DELAYED_WORK(&ts->work, stmpe_work);
338 error = devm_request_threaded_irq(&pdev->dev, ts_irq,
339 NULL, stmpe_ts_handler,
340 IRQF_ONESHOT, STMPE_TS_NAME, ts);
342 dev_err(&pdev->dev, "Failed to request IRQ %d\n", ts_irq);
346 error = stmpe_init_hw(ts);
350 idev->name = STMPE_TS_NAME;
351 idev->phys = STMPE_TS_NAME"/input0";
352 idev->id.bustype = BUS_I2C;
353 idev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
354 idev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
356 idev->open = stmpe_ts_open;
357 idev->close = stmpe_ts_close;
359 input_set_drvdata(idev, ts);
361 input_set_abs_params(idev, ABS_X, 0, XY_MASK, 0, 0);
362 input_set_abs_params(idev, ABS_Y, 0, XY_MASK, 0, 0);
363 input_set_abs_params(idev, ABS_PRESSURE, 0x0, 0xff, 0, 0);
365 error = input_register_device(idev);
367 dev_err(&pdev->dev, "Could not register input device\n");
374 static int __devexit stmpe_ts_remove(struct platform_device *pdev)
376 struct stmpe_touch *ts = platform_get_drvdata(pdev);
378 stmpe_disable(ts->stmpe, STMPE_BLOCK_TOUCHSCREEN);
383 static struct platform_driver stmpe_ts_driver = {
385 .name = STMPE_TS_NAME,
386 .owner = THIS_MODULE,
388 .probe = stmpe_input_probe,
389 .remove = stmpe_ts_remove,
391 module_platform_driver(stmpe_ts_driver);
393 MODULE_AUTHOR("Luotao Fu <l.fu@pengutronix.de>");
394 MODULE_DESCRIPTION("STMPEXXX touchscreen driver");
395 MODULE_LICENSE("GPL");
396 MODULE_ALIAS("platform:" STMPE_TS_NAME);