2 * TI Touch Screen driver
4 * Copyright (C) 2011 Texas Instruments Incorporated - http://www.ti.com/
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License as
8 * published by the Free Software Foundation version 2.
10 * This program is distributed "as is" WITHOUT ANY WARRANTY of any
11 * kind, whether express or implied; without even the implied warranty
12 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
17 #include <linux/kernel.h>
18 #include <linux/err.h>
19 #include <linux/module.h>
20 #include <linux/input.h>
21 #include <linux/slab.h>
22 #include <linux/interrupt.h>
23 #include <linux/clk.h>
24 #include <linux/platform_device.h>
26 #include <linux/delay.h>
28 #include <linux/of_device.h>
29 #include <linux/sort.h>
31 #include <linux/mfd/ti_am335x_tscadc.h>
33 #define ADCFSM_STEPID 0x10
34 #define SEQ_SETTLE 275
35 #define MAX_12BIT ((1 << 12) - 1)
37 static const int config_pins
[] = {
45 struct input_dev
*input
;
46 struct ti_tscadc_dev
*mfd_tscadc
;
49 unsigned int x_plate_resistance
;
51 int coordinate_readouts
;
53 u32 bit_xp
, bit_xn
, bit_yp
, bit_yn
;
54 u32 inp_xp
, inp_xn
, inp_yp
, inp_yn
;
59 static unsigned int titsc_readl(struct titsc
*ts
, unsigned int reg
)
61 return readl(ts
->mfd_tscadc
->tscadc_base
+ reg
);
64 static void titsc_writel(struct titsc
*tsc
, unsigned int reg
,
67 writel(val
, tsc
->mfd_tscadc
->tscadc_base
+ reg
);
70 static int titsc_config_wires(struct titsc
*ts_dev
)
76 for (i
= 0; i
< 4; i
++) {
78 * Get the order in which TSC wires are attached
79 * w.r.t. each of the analog input lines on the EVM.
81 analog_line
[i
] = (ts_dev
->config_inp
[i
] & 0xF0) >> 4;
82 wire_order
[i
] = ts_dev
->config_inp
[i
] & 0x0F;
83 if (WARN_ON(analog_line
[i
] > 7))
85 if (WARN_ON(wire_order
[i
] > ARRAY_SIZE(config_pins
)))
89 for (i
= 0; i
< 4; i
++) {
93 an_line
= analog_line
[i
];
94 wi_order
= wire_order
[i
];
95 bit_cfg
= config_pins
[wi_order
];
100 ts_dev
->bit_xp
= bit_cfg
;
101 ts_dev
->inp_xp
= an_line
;
105 ts_dev
->bit_xn
= bit_cfg
;
106 ts_dev
->inp_xn
= an_line
;
110 ts_dev
->bit_yp
= bit_cfg
;
111 ts_dev
->inp_yp
= an_line
;
114 ts_dev
->bit_yn
= bit_cfg
;
115 ts_dev
->inp_yn
= an_line
;
122 static void titsc_step_config(struct titsc
*ts_dev
)
126 int end_step
, first_step
, tsc_steps
;
129 config
= STEPCONFIG_MODE_HWSYNC
|
130 STEPCONFIG_AVG_16
| ts_dev
->bit_xp
;
131 switch (ts_dev
->wires
) {
133 config
|= STEPCONFIG_INP(ts_dev
->inp_yp
) | ts_dev
->bit_xn
;
136 config
|= ts_dev
->bit_yn
|
137 STEPCONFIG_INP_AN4
| ts_dev
->bit_xn
|
141 config
|= STEPCONFIG_INP(ts_dev
->inp_yp
) | ts_dev
->bit_xn
;
145 tsc_steps
= ts_dev
->coordinate_readouts
* 2 + 2;
146 first_step
= TOTAL_STEPS
- tsc_steps
;
147 /* Steps 16 to 16-coordinate_readouts is for X */
148 end_step
= first_step
+ tsc_steps
;
149 for (i
= end_step
- ts_dev
->coordinate_readouts
; i
< end_step
; i
++) {
150 titsc_writel(ts_dev
, REG_STEPCONFIG(i
), config
);
151 titsc_writel(ts_dev
, REG_STEPDELAY(i
), STEPCONFIG_OPENDLY
);
155 config
= STEPCONFIG_MODE_HWSYNC
|
156 STEPCONFIG_AVG_16
| ts_dev
->bit_yn
|
157 STEPCONFIG_INM_ADCREFM
;
158 switch (ts_dev
->wires
) {
160 config
|= ts_dev
->bit_yp
| STEPCONFIG_INP(ts_dev
->inp_xp
);
163 config
|= ts_dev
->bit_xp
| STEPCONFIG_INP_AN4
|
164 ts_dev
->bit_xn
| ts_dev
->bit_yp
;
167 config
|= ts_dev
->bit_yp
| STEPCONFIG_INP(ts_dev
->inp_xp
);
171 /* 1 ... coordinate_readouts is for Y */
172 end_step
= first_step
+ ts_dev
->coordinate_readouts
;
173 for (i
= first_step
; i
< end_step
; i
++) {
174 titsc_writel(ts_dev
, REG_STEPCONFIG(i
), config
);
175 titsc_writel(ts_dev
, REG_STEPDELAY(i
), STEPCONFIG_OPENDLY
);
178 /* Make CHARGECONFIG same as IDLECONFIG */
180 config
= titsc_readl(ts_dev
, REG_IDLECONFIG
);
181 titsc_writel(ts_dev
, REG_CHARGECONFIG
, config
);
182 titsc_writel(ts_dev
, REG_CHARGEDELAY
, ts_dev
->charge_delay
);
184 /* coordinate_readouts + 1 ... coordinate_readouts + 2 is for Z */
185 config
= STEPCONFIG_MODE_HWSYNC
|
186 STEPCONFIG_AVG_16
| ts_dev
->bit_yp
|
187 ts_dev
->bit_xn
| STEPCONFIG_INM_ADCREFM
|
188 STEPCONFIG_INP(ts_dev
->inp_xp
);
189 titsc_writel(ts_dev
, REG_STEPCONFIG(end_step
), config
);
190 titsc_writel(ts_dev
, REG_STEPDELAY(end_step
),
194 config
|= STEPCONFIG_INP(ts_dev
->inp_yn
);
195 titsc_writel(ts_dev
, REG_STEPCONFIG(end_step
), config
);
196 titsc_writel(ts_dev
, REG_STEPDELAY(end_step
),
199 /* The steps end ... end - readouts * 2 + 2 and bit 0 for TS_Charge */
201 for (i
= 0; i
< tsc_steps
; i
++)
202 stepenable
|= 1 << (first_step
+ i
+ 1);
204 ts_dev
->step_mask
= stepenable
;
205 am335x_tsc_se_set_cache(ts_dev
->mfd_tscadc
, ts_dev
->step_mask
);
208 static int titsc_cmp_coord(const void *a
, const void *b
)
210 return *(int *)a
- *(int *)b
;
213 static void titsc_read_coordinates(struct titsc
*ts_dev
,
214 u32
*x
, u32
*y
, u32
*z1
, u32
*z2
)
216 unsigned int yvals
[7], xvals
[7];
217 unsigned int i
, xsum
= 0, ysum
= 0;
218 unsigned int creads
= ts_dev
->coordinate_readouts
;
220 for (i
= 0; i
< creads
; i
++) {
221 yvals
[i
] = titsc_readl(ts_dev
, REG_FIFO0
);
225 *z1
= titsc_readl(ts_dev
, REG_FIFO0
);
227 *z2
= titsc_readl(ts_dev
, REG_FIFO0
);
230 for (i
= 0; i
< creads
; i
++) {
231 xvals
[i
] = titsc_readl(ts_dev
, REG_FIFO0
);
236 * If co-ordinates readouts is less than 4 then
237 * report the average. In case of 4 or more
238 * readouts, sort the co-ordinate samples, drop
239 * min and max values and report the average of
243 for (i
= 0; i
< creads
; i
++) {
250 sort(yvals
, creads
, sizeof(unsigned int),
251 titsc_cmp_coord
, NULL
);
252 sort(xvals
, creads
, sizeof(unsigned int),
253 titsc_cmp_coord
, NULL
);
254 for (i
= 1; i
< creads
- 1; i
++) {
265 static irqreturn_t
titsc_irq(int irq
, void *dev
)
267 struct titsc
*ts_dev
= dev
;
268 struct input_dev
*input_dev
= ts_dev
->input
;
269 unsigned int fsm
, status
, irqclr
= 0;
270 unsigned int x
= 0, y
= 0;
271 unsigned int z1
, z2
, z
;
273 status
= titsc_readl(ts_dev
, REG_RAWIRQSTATUS
);
274 if (status
& IRQENB_HW_PEN
) {
275 ts_dev
->pen_down
= true;
276 irqclr
|= IRQENB_HW_PEN
;
279 if (status
& IRQENB_PENUP
) {
280 fsm
= titsc_readl(ts_dev
, REG_ADCFSM
);
281 if (fsm
== ADCFSM_STEPID
) {
282 ts_dev
->pen_down
= false;
283 input_report_key(input_dev
, BTN_TOUCH
, 0);
284 input_report_abs(input_dev
, ABS_PRESSURE
, 0);
285 input_sync(input_dev
);
287 ts_dev
->pen_down
= true;
289 irqclr
|= IRQENB_PENUP
;
292 if (status
& IRQENB_EOS
)
293 irqclr
|= IRQENB_EOS
;
296 * ADC and touchscreen share the IRQ line.
297 * FIFO1 interrupts are used by ADC. Handle FIFO0 IRQs here only
299 if (status
& IRQENB_FIFO0THRES
) {
301 titsc_read_coordinates(ts_dev
, &x
, &y
, &z1
, &z2
);
303 if (ts_dev
->pen_down
&& z1
!= 0 && z2
!= 0) {
305 * Calculate pressure using formula
306 * Resistance(touch) = x plate resistance *
307 * x postion/4096 * ((z2 / z1) - 1)
311 z
*= ts_dev
->x_plate_resistance
;
313 z
= (z
+ 2047) >> 12;
315 if (z
<= MAX_12BIT
) {
316 input_report_abs(input_dev
, ABS_X
, x
);
317 input_report_abs(input_dev
, ABS_Y
, y
);
318 input_report_abs(input_dev
, ABS_PRESSURE
, z
);
319 input_report_key(input_dev
, BTN_TOUCH
, 1);
320 input_sync(input_dev
);
323 irqclr
|= IRQENB_FIFO0THRES
;
326 titsc_writel(ts_dev
, REG_IRQSTATUS
, irqclr
);
327 if (status
& IRQENB_EOS
)
328 am335x_tsc_se_set_cache(ts_dev
->mfd_tscadc
,
335 static int titsc_parse_dt(struct platform_device
*pdev
,
336 struct titsc
*ts_dev
)
338 struct device_node
*node
= pdev
->dev
.of_node
;
344 err
= of_property_read_u32(node
, "ti,wires", &ts_dev
->wires
);
347 switch (ts_dev
->wires
) {
356 err
= of_property_read_u32(node
, "ti,x-plate-resistance",
357 &ts_dev
->x_plate_resistance
);
362 * Try with the new binding first. If it fails, try again with
363 * bogus, miss-spelled version.
365 err
= of_property_read_u32(node
, "ti,coordinate-readouts",
366 &ts_dev
->coordinate_readouts
);
368 dev_warn(&pdev
->dev
, "please use 'ti,coordinate-readouts' instead\n");
369 err
= of_property_read_u32(node
, "ti,coordiante-readouts",
370 &ts_dev
->coordinate_readouts
);
376 if (ts_dev
->coordinate_readouts
<= 0) {
378 "invalid co-ordinate readouts, resetting it to 5\n");
379 ts_dev
->coordinate_readouts
= 5;
382 err
= of_property_read_u32(node
, "ti,charge-delay",
383 &ts_dev
->charge_delay
);
385 * If ti,charge-delay value is not specified, then use
386 * CHARGEDLY_OPENDLY as the default value.
389 ts_dev
->charge_delay
= CHARGEDLY_OPENDLY
;
390 dev_warn(&pdev
->dev
, "ti,charge-delay not specified\n");
393 return of_property_read_u32_array(node
, "ti,wire-config",
394 ts_dev
->config_inp
, ARRAY_SIZE(ts_dev
->config_inp
));
398 * The functions for inserting/removing driver as a module.
401 static int titsc_probe(struct platform_device
*pdev
)
403 struct titsc
*ts_dev
;
404 struct input_dev
*input_dev
;
405 struct ti_tscadc_dev
*tscadc_dev
= ti_tscadc_dev_get(pdev
);
408 /* Allocate memory for device */
409 ts_dev
= kzalloc(sizeof(struct titsc
), GFP_KERNEL
);
410 input_dev
= input_allocate_device();
411 if (!ts_dev
|| !input_dev
) {
412 dev_err(&pdev
->dev
, "failed to allocate memory.\n");
417 tscadc_dev
->tsc
= ts_dev
;
418 ts_dev
->mfd_tscadc
= tscadc_dev
;
419 ts_dev
->input
= input_dev
;
420 ts_dev
->irq
= tscadc_dev
->irq
;
422 err
= titsc_parse_dt(pdev
, ts_dev
);
424 dev_err(&pdev
->dev
, "Could not find valid DT data.\n");
428 err
= request_irq(ts_dev
->irq
, titsc_irq
,
429 IRQF_SHARED
, pdev
->dev
.driver
->name
, ts_dev
);
431 dev_err(&pdev
->dev
, "failed to allocate irq.\n");
435 titsc_writel(ts_dev
, REG_IRQENABLE
, IRQENB_FIFO0THRES
);
436 titsc_writel(ts_dev
, REG_IRQENABLE
, IRQENB_EOS
);
437 err
= titsc_config_wires(ts_dev
);
439 dev_err(&pdev
->dev
, "wrong i/p wire configuration\n");
442 titsc_step_config(ts_dev
);
443 titsc_writel(ts_dev
, REG_FIFO0THR
,
444 ts_dev
->coordinate_readouts
* 2 + 2 - 1);
446 input_dev
->name
= "ti-tsc";
447 input_dev
->dev
.parent
= &pdev
->dev
;
449 input_dev
->evbit
[0] = BIT_MASK(EV_KEY
) | BIT_MASK(EV_ABS
);
450 input_dev
->keybit
[BIT_WORD(BTN_TOUCH
)] = BIT_MASK(BTN_TOUCH
);
452 input_set_abs_params(input_dev
, ABS_X
, 0, MAX_12BIT
, 0, 0);
453 input_set_abs_params(input_dev
, ABS_Y
, 0, MAX_12BIT
, 0, 0);
454 input_set_abs_params(input_dev
, ABS_PRESSURE
, 0, MAX_12BIT
, 0, 0);
456 /* register to the input system */
457 err
= input_register_device(input_dev
);
461 platform_set_drvdata(pdev
, ts_dev
);
465 free_irq(ts_dev
->irq
, ts_dev
);
467 input_free_device(input_dev
);
472 static int titsc_remove(struct platform_device
*pdev
)
474 struct titsc
*ts_dev
= platform_get_drvdata(pdev
);
477 free_irq(ts_dev
->irq
, ts_dev
);
479 /* total steps followed by the enable mask */
480 steps
= 2 * ts_dev
->coordinate_readouts
+ 2;
481 steps
= (1 << steps
) - 1;
482 am335x_tsc_se_clr(ts_dev
->mfd_tscadc
, steps
);
484 input_unregister_device(ts_dev
->input
);
490 static int __maybe_unused
titsc_suspend(struct device
*dev
)
492 struct titsc
*ts_dev
= dev_get_drvdata(dev
);
493 struct ti_tscadc_dev
*tscadc_dev
;
496 tscadc_dev
= ti_tscadc_dev_get(to_platform_device(dev
));
497 if (device_may_wakeup(tscadc_dev
->dev
)) {
498 idle
= titsc_readl(ts_dev
, REG_IRQENABLE
);
499 titsc_writel(ts_dev
, REG_IRQENABLE
,
500 (idle
| IRQENB_HW_PEN
));
501 titsc_writel(ts_dev
, REG_IRQWAKEUP
, IRQWKUP_ENB
);
506 static int __maybe_unused
titsc_resume(struct device
*dev
)
508 struct titsc
*ts_dev
= dev_get_drvdata(dev
);
509 struct ti_tscadc_dev
*tscadc_dev
;
511 tscadc_dev
= ti_tscadc_dev_get(to_platform_device(dev
));
512 if (device_may_wakeup(tscadc_dev
->dev
)) {
513 titsc_writel(ts_dev
, REG_IRQWAKEUP
,
515 titsc_writel(ts_dev
, REG_IRQCLR
, IRQENB_HW_PEN
);
517 titsc_step_config(ts_dev
);
518 titsc_writel(ts_dev
, REG_FIFO0THR
,
519 ts_dev
->coordinate_readouts
* 2 + 2 - 1);
523 static SIMPLE_DEV_PM_OPS(titsc_pm_ops
, titsc_suspend
, titsc_resume
);
525 static const struct of_device_id ti_tsc_dt_ids
[] = {
526 { .compatible
= "ti,am3359-tsc", },
529 MODULE_DEVICE_TABLE(of
, ti_tsc_dt_ids
);
531 static struct platform_driver ti_tsc_driver
= {
532 .probe
= titsc_probe
,
533 .remove
= titsc_remove
,
535 .name
= "TI-am335x-tsc",
537 .of_match_table
= ti_tsc_dt_ids
,
540 module_platform_driver(ti_tsc_driver
);
542 MODULE_DESCRIPTION("TI touchscreen controller driver");
543 MODULE_AUTHOR("Rachna Patil <rachna@ti.com>");
544 MODULE_LICENSE("GPL");