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Linux/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/delay.h>
 29 #include <linux/irq.h>
 30 #include <linux/interrupt.h>
 31 #include <linux/wm97xx.h>
 32 #include <linux/io.h>
 33 #include <linux/gpio.h>
 34 
 35 #include <mach/regs-ac97.h>
 36 
 37 #include <asm/mach-types.h>
 38 
 39 struct continuous {
 40         u16 id;    /* codec id */
 41         u8 code;   /* continuous code */
 42         u8 reads;  /* number of coord reads per read cycle */
 43         u32 speed; /* number of coords per second */
 44 };
 45 
 46 #define WM_READS(sp) ((sp / HZ) + 1)
 47 
 48 static const struct continuous cinfo[] = {
 49         {WM9705_ID2, 0, WM_READS(94), 94},
 50         {WM9705_ID2, 1, WM_READS(188), 188},
 51         {WM9705_ID2, 2, WM_READS(375), 375},
 52         {WM9705_ID2, 3, WM_READS(750), 750},
 53         {WM9712_ID2, 0, WM_READS(94), 94},
 54         {WM9712_ID2, 1, WM_READS(188), 188},
 55         {WM9712_ID2, 2, WM_READS(375), 375},
 56         {WM9712_ID2, 3, WM_READS(750), 750},
 57         {WM9713_ID2, 0, WM_READS(94), 94},
 58         {WM9713_ID2, 1, WM_READS(120), 120},
 59         {WM9713_ID2, 2, WM_READS(154), 154},
 60         {WM9713_ID2, 3, WM_READS(188), 188},
 61 };
 62 
 63 /* continuous speed index */
 64 static int sp_idx;
 65 static u16 last, tries;
 66 static int irq;
 67 
 68 /*
 69  * Pen sampling frequency (Hz) in continuous mode.
 70  */
 71 static int cont_rate = 200;
 72 module_param(cont_rate, int, 0);
 73 MODULE_PARM_DESC(cont_rate, "Sampling rate in continuous mode (Hz)");
 74 
 75 /*
 76  * Pen down detection.
 77  *
 78  * This driver can either poll or use an interrupt to indicate a pen down
 79  * event. If the irq request fails then it will fall back to polling mode.
 80  */
 81 static int pen_int;
 82 module_param(pen_int, int, 0);
 83 MODULE_PARM_DESC(pen_int, "Pen down detection (1 = interrupt, 0 = polling)");
 84 
 85 /*
 86  * Pressure readback.
 87  *
 88  * Set to 1 to read back pen down pressure
 89  */
 90 static int pressure;
 91 module_param(pressure, int, 0);
 92 MODULE_PARM_DESC(pressure, "Pressure readback (1 = pressure, 0 = no pressure)");
 93 
 94 /*
 95  * AC97 touch data slot.
 96  *
 97  * Touch screen readback data ac97 slot
 98  */
 99 static int ac97_touch_slot = 5;
100 module_param(ac97_touch_slot, int, 0);
101 MODULE_PARM_DESC(ac97_touch_slot, "Touch screen data slot AC97 number");
102 
103 
104 /* flush AC97 slot 5 FIFO on pxa machines */
105 #ifdef CONFIG_PXA27x
106 static void wm97xx_acc_pen_up(struct wm97xx *wm)
107 {
108         schedule_timeout_uninterruptible(1);
109 
110         while (MISR & (1 << 2))
111                 MODR;
112 }
113 #else
114 static void wm97xx_acc_pen_up(struct wm97xx *wm)
115 {
116         unsigned int count;
117 
118         schedule_timeout_uninterruptible(1);
119 
120         for (count = 0; count < 16; count++)
121                 MODR;
122 }
123 #endif
124 
125 static int wm97xx_acc_pen_down(struct wm97xx *wm)
126 {
127         u16 x, y, p = 0x100 | WM97XX_ADCSEL_PRES;
128         int reads = 0;
129 
130         /* When the AC97 queue has been drained we need to allow time
131          * to buffer up samples otherwise we end up spinning polling
132          * for samples.  The controller can't have a suitably low
133          * threshold set to use the notifications it gives.
134          */
135         schedule_timeout_uninterruptible(1);
136 
137         if (tries > 5) {
138                 tries = 0;
139                 return RC_PENUP;
140         }
141 
142         x = MODR;
143         if (x == last) {
144                 tries++;
145                 return RC_AGAIN;
146         }
147         last = x;
148         do {
149                 if (reads)
150                         x = MODR;
151                 y = MODR;
152                 if (pressure)
153                         p = MODR;
154 
155                 dev_dbg(wm->dev, "Raw coordinates: x=%x, y=%x, p=%x\n",
156                         x, y, p);
157 
158                 /* are samples valid */
159                 if ((x & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_X ||
160                     (y & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_Y ||
161                     (p & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_PRES)
162                         goto up;
163 
164                 /* coordinate is good */
165                 tries = 0;
166                 input_report_abs(wm->input_dev, ABS_X, x & 0xfff);
167                 input_report_abs(wm->input_dev, ABS_Y, y & 0xfff);
168                 input_report_abs(wm->input_dev, ABS_PRESSURE, p & 0xfff);
169                 input_report_key(wm->input_dev, BTN_TOUCH, (p != 0));
170                 input_sync(wm->input_dev);
171                 reads++;
172         } while (reads < cinfo[sp_idx].reads);
173 up:
174         return RC_PENDOWN | RC_AGAIN;
175 }
176 
177 static int wm97xx_acc_startup(struct wm97xx *wm)
178 {
179         int idx = 0, ret = 0;
180 
181         /* check we have a codec */
182         if (wm->ac97 == NULL)
183                 return -ENODEV;
184 
185         /* Go you big red fire engine */
186         for (idx = 0; idx < ARRAY_SIZE(cinfo); idx++) {
187                 if (wm->id != cinfo[idx].id)
188                         continue;
189                 sp_idx = idx;
190                 if (cont_rate <= cinfo[idx].speed)
191                         break;
192         }
193         wm->acc_rate = cinfo[sp_idx].code;
194         wm->acc_slot = ac97_touch_slot;
195         dev_info(wm->dev,
196                  "mainstone accelerated touchscreen driver, %d samples/sec\n",
197                  cinfo[sp_idx].speed);
198 
199         /* IRQ driven touchscreen is used on Palm hardware */
200         if (machine_is_palmt5() || machine_is_palmtx() || machine_is_palmld()) {
201                 pen_int = 1;
202                 irq = 27;
203                 /* There is some obscure mutant of WM9712 interbred with WM9713
204                  * used on Palm HW */
205                 wm->variant = WM97xx_WM1613;
206         } else if (machine_is_mainstone() && pen_int)
207                 irq = 4;
208 
209         if (irq) {
210                 ret = gpio_request(irq, "Touchscreen IRQ");
211                 if (ret)
212                         goto out;
213 
214                 ret = gpio_direction_input(irq);
215                 if (ret) {
216                         gpio_free(irq);
217                         goto out;
218                 }
219 
220                 wm->pen_irq = gpio_to_irq(irq);
221                 irq_set_irq_type(wm->pen_irq, IRQ_TYPE_EDGE_BOTH);
222         } else /* pen irq not supported */
223                 pen_int = 0;
224 
225         /* codec specific irq config */
226         if (pen_int) {
227                 switch (wm->id) {
228                 case WM9705_ID2:
229                         break;
230                 case WM9712_ID2:
231                 case WM9713_ID2:
232                         /* use PEN_DOWN GPIO 13 to assert IRQ on GPIO line 2 */
233                         wm97xx_config_gpio(wm, WM97XX_GPIO_13, WM97XX_GPIO_IN,
234                                            WM97XX_GPIO_POL_HIGH,
235                                            WM97XX_GPIO_STICKY,
236                                            WM97XX_GPIO_WAKE);
237                         wm97xx_config_gpio(wm, WM97XX_GPIO_2, WM97XX_GPIO_OUT,
238                                            WM97XX_GPIO_POL_HIGH,
239                                            WM97XX_GPIO_NOTSTICKY,
240                                            WM97XX_GPIO_NOWAKE);
241                         break;
242                 default:
243                         dev_err(wm->dev,
244                                 "pen down irq not supported on this device\n");
245                         pen_int = 0;
246                         break;
247                 }
248         }
249 
250 out:
251         return ret;
252 }
253 
254 static void wm97xx_acc_shutdown(struct wm97xx *wm)
255 {
256         /* codec specific deconfig */
257         if (pen_int) {
258                 if (irq)
259                         gpio_free(irq);
260                 wm->pen_irq = 0;
261         }
262 }
263 
264 static void wm97xx_irq_enable(struct wm97xx *wm, int enable)
265 {
266         if (enable)
267                 enable_irq(wm->pen_irq);
268         else
269                 disable_irq_nosync(wm->pen_irq);
270 }
271 
272 static struct wm97xx_mach_ops mainstone_mach_ops = {
273         .acc_enabled = 1,
274         .acc_pen_up = wm97xx_acc_pen_up,
275         .acc_pen_down = wm97xx_acc_pen_down,
276         .acc_startup = wm97xx_acc_startup,
277         .acc_shutdown = wm97xx_acc_shutdown,
278         .irq_enable = wm97xx_irq_enable,
279         .irq_gpio = WM97XX_GPIO_2,
280 };
281 
282 static int mainstone_wm97xx_probe(struct platform_device *pdev)
283 {
284         struct wm97xx *wm = platform_get_drvdata(pdev);
285 
286         return wm97xx_register_mach_ops(wm, &mainstone_mach_ops);
287 }
288 
289 static int mainstone_wm97xx_remove(struct platform_device *pdev)
290 {
291         struct wm97xx *wm = platform_get_drvdata(pdev);
292 
293         wm97xx_unregister_mach_ops(wm);
294         return 0;
295 }
296 
297 static struct platform_driver mainstone_wm97xx_driver = {
298         .probe = mainstone_wm97xx_probe,
299         .remove = mainstone_wm97xx_remove,
300         .driver = {
301                 .name = "wm97xx-touch",
302         },
303 };
304 module_platform_driver(mainstone_wm97xx_driver);
305 
306 /* Module information */
307 MODULE_AUTHOR("Liam Girdwood <lrg@slimlogic.co.uk>");
308 MODULE_DESCRIPTION("wm97xx continuous touch driver for mainstone");
309 MODULE_LICENSE("GPL");
310 

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