b6b8b1c7eceaf99b6eec1d613f3511c4a4a65550
[linux-2.6.git] / drivers / input / touchscreen / mainstone-wm97xx.c
1 /*
2  * mainstone-wm97xx.c  --  Mainstone Continuous Touch screen driver for
3  *                         Wolfson WM97xx AC97 Codecs.
4  *
5  * Copyright 2004, 2007 Wolfson Microelectronics PLC.
6  * Author: Liam Girdwood <lrg@slimlogic.co.uk>
7  * Parts Copyright : Ian Molton <spyro@f2s.com>
8  *                   Andrew Zabolotny <zap@homelink.ru>
9  *
10  *  This program is free software; you can redistribute  it and/or modify it
11  *  under  the terms of  the GNU General  Public License as published by the
12  *  Free Software Foundation;  either version 2 of the  License, or (at your
13  *  option) any later version.
14  *
15  * Notes:
16  *     This is a wm97xx extended touch driver to capture touch
17  *     data in a continuous manner on the Intel XScale architecture
18  *
19  *  Features:
20  *       - codecs supported:- WM9705, WM9712, WM9713
21  *       - processors supported:- Intel XScale PXA25x, PXA26x, PXA27x
22  *
23  */
24
25 #include <linux/module.h>
26 #include <linux/moduleparam.h>
27 #include <linux/kernel.h>
28 #include <linux/init.h>
29 #include <linux/delay.h>
30 #include <linux/irq.h>
31 #include <linux/interrupt.h>
32 #include <linux/wm97xx.h>
33 #include <linux/io.h>
34 #include <linux/gpio.h>
35
36 #include <mach/regs-ac97.h>
37
38 #include <asm/mach-types.h>
39
40 struct continuous {
41         u16 id;    /* codec id */
42         u8 code;   /* continuous code */
43         u8 reads;  /* number of coord reads per read cycle */
44         u32 speed; /* number of coords per second */
45 };
46
47 #define WM_READS(sp) ((sp / HZ) + 1)
48
49 static const struct continuous cinfo[] = {
50         {WM9705_ID2, 0, WM_READS(94), 94},
51         {WM9705_ID2, 1, WM_READS(188), 188},
52         {WM9705_ID2, 2, WM_READS(375), 375},
53         {WM9705_ID2, 3, WM_READS(750), 750},
54         {WM9712_ID2, 0, WM_READS(94), 94},
55         {WM9712_ID2, 1, WM_READS(188), 188},
56         {WM9712_ID2, 2, WM_READS(375), 375},
57         {WM9712_ID2, 3, WM_READS(750), 750},
58         {WM9713_ID2, 0, WM_READS(94), 94},
59         {WM9713_ID2, 1, WM_READS(120), 120},
60         {WM9713_ID2, 2, WM_READS(154), 154},
61         {WM9713_ID2, 3, WM_READS(188), 188},
62 };
63
64 /* continuous speed index */
65 static int sp_idx;
66 static u16 last, tries;
67 static int irq;
68
69 /*
70  * Pen sampling frequency (Hz) in continuous mode.
71  */
72 static int cont_rate = 200;
73 module_param(cont_rate, int, 0);
74 MODULE_PARM_DESC(cont_rate, "Sampling rate in continuous mode (Hz)");
75
76 /*
77  * Pen down detection.
78  *
79  * This driver can either poll or use an interrupt to indicate a pen down
80  * event. If the irq request fails then it will fall back to polling mode.
81  */
82 static int pen_int;
83 module_param(pen_int, int, 0);
84 MODULE_PARM_DESC(pen_int, "Pen down detection (1 = interrupt, 0 = polling)");
85
86 /*
87  * Pressure readback.
88  *
89  * Set to 1 to read back pen down pressure
90  */
91 static int pressure;
92 module_param(pressure, int, 0);
93 MODULE_PARM_DESC(pressure, "Pressure readback (1 = pressure, 0 = no pressure)");
94
95 /*
96  * AC97 touch data slot.
97  *
98  * Touch screen readback data ac97 slot
99  */
100 static int ac97_touch_slot = 5;
101 module_param(ac97_touch_slot, int, 0);
102 MODULE_PARM_DESC(ac97_touch_slot, "Touch screen data slot AC97 number");
103
104
105 /* flush AC97 slot 5 FIFO on pxa machines */
106 #ifdef CONFIG_PXA27x
107 static void wm97xx_acc_pen_up(struct wm97xx *wm)
108 {
109         schedule_timeout_uninterruptible(1);
110
111         while (MISR & (1 << 2))
112                 MODR;
113 }
114 #else
115 static void wm97xx_acc_pen_up(struct wm97xx *wm)
116 {
117         unsigned int count;
118
119         schedule_timeout_uninterruptible(1);
120
121         for (count = 0; count < 16; count++)
122                 MODR;
123 }
124 #endif
125
126 static int wm97xx_acc_pen_down(struct wm97xx *wm)
127 {
128         u16 x, y, p = 0x100 | WM97XX_ADCSEL_PRES;
129         int reads = 0;
130
131         /* When the AC97 queue has been drained we need to allow time
132          * to buffer up samples otherwise we end up spinning polling
133          * for samples.  The controller can't have a suitably low
134          * threshold set to use the notifications it gives.
135          */
136         schedule_timeout_uninterruptible(1);
137
138         if (tries > 5) {
139                 tries = 0;
140                 return RC_PENUP;
141         }
142
143         x = MODR;
144         if (x == last) {
145                 tries++;
146                 return RC_AGAIN;
147         }
148         last = x;
149         do {
150                 if (reads)
151                         x = MODR;
152                 y = MODR;
153                 if (pressure)
154                         p = MODR;
155
156                 dev_dbg(wm->dev, "Raw coordinates: x=%x, y=%x, p=%x\n",
157                         x, y, p);
158
159                 /* are samples valid */
160                 if ((x & WM97XX_ADCSRC_MASK) != WM97XX_ADCSEL_X ||
161                     (y & WM97XX_ADCSRC_MASK) != WM97XX_ADCSEL_Y ||
162                     (p & WM97XX_ADCSRC_MASK) != WM97XX_ADCSEL_PRES)
163                         goto up;
164
165                 /* coordinate is good */
166                 tries = 0;
167                 input_report_abs(wm->input_dev, ABS_X, x & 0xfff);
168                 input_report_abs(wm->input_dev, ABS_Y, y & 0xfff);
169                 input_report_abs(wm->input_dev, ABS_PRESSURE, p & 0xfff);
170                 input_report_key(wm->input_dev, BTN_TOUCH, (p != 0));
171                 input_sync(wm->input_dev);
172                 reads++;
173         } while (reads < cinfo[sp_idx].reads);
174 up:
175         return RC_PENDOWN | RC_AGAIN;
176 }
177
178 static int wm97xx_acc_startup(struct wm97xx *wm)
179 {
180         int idx = 0, ret = 0;
181
182         /* check we have a codec */
183         if (wm->ac97 == NULL)
184                 return -ENODEV;
185
186         /* Go you big red fire engine */
187         for (idx = 0; idx < ARRAY_SIZE(cinfo); idx++) {
188                 if (wm->id != cinfo[idx].id)
189                         continue;
190                 sp_idx = idx;
191                 if (cont_rate <= cinfo[idx].speed)
192                         break;
193         }
194         wm->acc_rate = cinfo[sp_idx].code;
195         wm->acc_slot = ac97_touch_slot;
196         dev_info(wm->dev,
197                  "mainstone accelerated touchscreen driver, %d samples/sec\n",
198                  cinfo[sp_idx].speed);
199
200         /* IRQ driven touchscreen is used on Palm hardware */
201         if (machine_is_palmt5() || machine_is_palmtx() || machine_is_palmld()) {
202                 pen_int = 1;
203                 irq = 27;
204                 /* There is some obscure mutant of WM9712 interbred with WM9713
205                  * used on Palm HW */
206                 wm->variant = WM97xx_WM1613;
207         } else if (machine_is_mainstone() && pen_int)
208                 irq = 4;
209
210         if (irq) {
211                 ret = gpio_request(irq, "Touchscreen IRQ");
212                 if (ret)
213                         goto out;
214
215                 ret = gpio_direction_input(irq);
216                 if (ret) {
217                         gpio_free(irq);
218                         goto out;
219                 }
220
221                 wm->pen_irq = gpio_to_irq(irq);
222                 set_irq_type(wm->pen_irq, IRQ_TYPE_EDGE_BOTH);
223         } else /* pen irq not supported */
224                 pen_int = 0;
225
226         /* codec specific irq config */
227         if (pen_int) {
228                 switch (wm->id) {
229                 case WM9705_ID2:
230                         break;
231                 case WM9712_ID2:
232                 case WM9713_ID2:
233                         /* use PEN_DOWN GPIO 13 to assert IRQ on GPIO line 2 */
234                         wm97xx_config_gpio(wm, WM97XX_GPIO_13, WM97XX_GPIO_IN,
235                                            WM97XX_GPIO_POL_HIGH,
236                                            WM97XX_GPIO_STICKY,
237                                            WM97XX_GPIO_WAKE);
238                         wm97xx_config_gpio(wm, WM97XX_GPIO_2, WM97XX_GPIO_OUT,
239                                            WM97XX_GPIO_POL_HIGH,
240                                            WM97XX_GPIO_NOTSTICKY,
241                                            WM97XX_GPIO_NOWAKE);
242                         break;
243                 default:
244                         dev_err(wm->dev,
245                                 "pen down irq not supported on this device\n");
246                         pen_int = 0;
247                         break;
248                 }
249         }
250
251 out:
252         return ret;
253 }
254
255 static void wm97xx_acc_shutdown(struct wm97xx *wm)
256 {
257         /* codec specific deconfig */
258         if (pen_int) {
259                 if (irq)
260                         gpio_free(irq);
261                 wm->pen_irq = 0;
262         }
263 }
264
265 static void wm97xx_irq_enable(struct wm97xx *wm, int enable)
266 {
267         if (enable)
268                 enable_irq(wm->pen_irq);
269         else
270                 disable_irq_nosync(wm->pen_irq);
271 }
272
273 static struct wm97xx_mach_ops mainstone_mach_ops = {
274         .acc_enabled = 1,
275         .acc_pen_up = wm97xx_acc_pen_up,
276         .acc_pen_down = wm97xx_acc_pen_down,
277         .acc_startup = wm97xx_acc_startup,
278         .acc_shutdown = wm97xx_acc_shutdown,
279         .irq_enable = wm97xx_irq_enable,
280         .irq_gpio = WM97XX_GPIO_2,
281 };
282
283 static int mainstone_wm97xx_probe(struct platform_device *pdev)
284 {
285         struct wm97xx *wm = platform_get_drvdata(pdev);
286
287         return wm97xx_register_mach_ops(wm, &mainstone_mach_ops);
288 }
289
290 static int mainstone_wm97xx_remove(struct platform_device *pdev)
291 {
292         struct wm97xx *wm = platform_get_drvdata(pdev);
293
294         wm97xx_unregister_mach_ops(wm);
295         return 0;
296 }
297
298 static struct platform_driver mainstone_wm97xx_driver = {
299         .probe = mainstone_wm97xx_probe,
300         .remove = mainstone_wm97xx_remove,
301         .driver = {
302                 .name = "wm97xx-touch",
303         },
304 };
305
306 static int __init mainstone_wm97xx_init(void)
307 {
308         return platform_driver_register(&mainstone_wm97xx_driver);
309 }
310
311 static void __exit mainstone_wm97xx_exit(void)
312 {
313         platform_driver_unregister(&mainstone_wm97xx_driver);
314 }
315
316 module_init(mainstone_wm97xx_init);
317 module_exit(mainstone_wm97xx_exit);
318
319 /* Module information */
320 MODULE_AUTHOR("Liam Girdwood <lrg@slimlogic.co.uk>");
321 MODULE_DESCRIPTION("wm97xx continuous touch driver for mainstone");
322 MODULE_LICENSE("GPL");