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Linux/drivers/input/touchscreen/zylonite-wm97xx.c

  1 /*
  2  * zylonite-wm97xx.c  --  Zylonite Continuous Touch screen driver
  3  *
  4  * Copyright 2004, 2007, 2008 Wolfson Microelectronics PLC.
  5  * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
  6  * Parts Copyright : Ian Molton <spyro@f2s.com>
  7  *                   Andrew Zabolotny <zap@homelink.ru>
  8  *
  9  *  This program is free software; you can redistribute  it and/or modify it
 10  *  under  the terms of  the GNU General  Public License as published by the
 11  *  Free Software Foundation;  either version 2 of the  License, or (at your
 12  *  option) any later version.
 13  *
 14  * Notes:
 15  *     This is a wm97xx extended touch driver supporting interrupt driven
 16  *     and continuous operation on Marvell Zylonite development systems
 17  *     (which have a WM9713 on board).
 18  */
 19 
 20 #include <linux/module.h>
 21 #include <linux/moduleparam.h>
 22 #include <linux/kernel.h>
 23 #include <linux/delay.h>
 24 #include <linux/gpio.h>
 25 #include <linux/irq.h>
 26 #include <linux/interrupt.h>
 27 #include <linux/io.h>
 28 #include <linux/wm97xx.h>
 29 
 30 #include <mach/hardware.h>
 31 #include <mach/mfp.h>
 32 #include <mach/regs-ac97.h>
 33 
 34 struct continuous {
 35         u16 id;    /* codec id */
 36         u8 code;   /* continuous code */
 37         u8 reads;  /* number of coord reads per read cycle */
 38         u32 speed; /* number of coords per second */
 39 };
 40 
 41 #define WM_READS(sp) ((sp / HZ) + 1)
 42 
 43 static const struct continuous cinfo[] = {
 44         { WM9713_ID2, 0, WM_READS(94),  94  },
 45         { WM9713_ID2, 1, WM_READS(120), 120 },
 46         { WM9713_ID2, 2, WM_READS(154), 154 },
 47         { WM9713_ID2, 3, WM_READS(188), 188 },
 48 };
 49 
 50 /* continuous speed index */
 51 static int sp_idx;
 52 
 53 /*
 54  * Pen sampling frequency (Hz) in continuous mode.
 55  */
 56 static int cont_rate = 200;
 57 module_param(cont_rate, int, 0);
 58 MODULE_PARM_DESC(cont_rate, "Sampling rate in continuous mode (Hz)");
 59 
 60 /*
 61  * Pressure readback.
 62  *
 63  * Set to 1 to read back pen down pressure
 64  */
 65 static int pressure;
 66 module_param(pressure, int, 0);
 67 MODULE_PARM_DESC(pressure, "Pressure readback (1 = pressure, 0 = no pressure)");
 68 
 69 /*
 70  * AC97 touch data slot.
 71  *
 72  * Touch screen readback data ac97 slot
 73  */
 74 static int ac97_touch_slot = 5;
 75 module_param(ac97_touch_slot, int, 0);
 76 MODULE_PARM_DESC(ac97_touch_slot, "Touch screen data slot AC97 number");
 77 
 78 
 79 /* flush AC97 slot 5 FIFO machines */
 80 static void wm97xx_acc_pen_up(struct wm97xx *wm)
 81 {
 82         int i;
 83 
 84         msleep(1);
 85 
 86         for (i = 0; i < 16; i++)
 87                 MODR;
 88 }
 89 
 90 static int wm97xx_acc_pen_down(struct wm97xx *wm)
 91 {
 92         u16 x, y, p = 0x100 | WM97XX_ADCSEL_PRES;
 93         int reads = 0;
 94         static u16 last, tries;
 95 
 96         /* When the AC97 queue has been drained we need to allow time
 97          * to buffer up samples otherwise we end up spinning polling
 98          * for samples.  The controller can't have a suitably low
 99          * threshold set to use the notifications it gives.
100          */
101         msleep(1);
102 
103         if (tries > 5) {
104                 tries = 0;
105                 return RC_PENUP;
106         }
107 
108         x = MODR;
109         if (x == last) {
110                 tries++;
111                 return RC_AGAIN;
112         }
113         last = x;
114         do {
115                 if (reads)
116                         x = MODR;
117                 y = MODR;
118                 if (pressure)
119                         p = MODR;
120 
121                 dev_dbg(wm->dev, "Raw coordinates: x=%x, y=%x, p=%x\n",
122                         x, y, p);
123 
124                 /* are samples valid */
125                 if ((x & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_X ||
126                     (y & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_Y ||
127                     (p & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_PRES)
128                         goto up;
129 
130                 /* coordinate is good */
131                 tries = 0;
132                 input_report_abs(wm->input_dev, ABS_X, x & 0xfff);
133                 input_report_abs(wm->input_dev, ABS_Y, y & 0xfff);
134                 input_report_abs(wm->input_dev, ABS_PRESSURE, p & 0xfff);
135                 input_report_key(wm->input_dev, BTN_TOUCH, (p != 0));
136                 input_sync(wm->input_dev);
137                 reads++;
138         } while (reads < cinfo[sp_idx].reads);
139 up:
140         return RC_PENDOWN | RC_AGAIN;
141 }
142 
143 static int wm97xx_acc_startup(struct wm97xx *wm)
144 {
145         int idx;
146 
147         /* check we have a codec */
148         if (wm->ac97 == NULL)
149                 return -ENODEV;
150 
151         /* Go you big red fire engine */
152         for (idx = 0; idx < ARRAY_SIZE(cinfo); idx++) {
153                 if (wm->id != cinfo[idx].id)
154                         continue;
155                 sp_idx = idx;
156                 if (cont_rate <= cinfo[idx].speed)
157                         break;
158         }
159         wm->acc_rate = cinfo[sp_idx].code;
160         wm->acc_slot = ac97_touch_slot;
161         dev_info(wm->dev,
162                  "zylonite accelerated touchscreen driver, %d samples/sec\n",
163                  cinfo[sp_idx].speed);
164 
165         return 0;
166 }
167 
168 static void wm97xx_irq_enable(struct wm97xx *wm, int enable)
169 {
170         if (enable)
171                 enable_irq(wm->pen_irq);
172         else
173                 disable_irq_nosync(wm->pen_irq);
174 }
175 
176 static struct wm97xx_mach_ops zylonite_mach_ops = {
177         .acc_enabled    = 1,
178         .acc_pen_up     = wm97xx_acc_pen_up,
179         .acc_pen_down   = wm97xx_acc_pen_down,
180         .acc_startup    = wm97xx_acc_startup,
181         .irq_enable     = wm97xx_irq_enable,
182         .irq_gpio       = WM97XX_GPIO_2,
183 };
184 
185 static int zylonite_wm97xx_probe(struct platform_device *pdev)
186 {
187         struct wm97xx *wm = platform_get_drvdata(pdev);
188         int gpio_touch_irq;
189 
190         if (cpu_is_pxa320())
191                 gpio_touch_irq = mfp_to_gpio(MFP_PIN_GPIO15);
192         else
193                 gpio_touch_irq = mfp_to_gpio(MFP_PIN_GPIO26);
194 
195         wm->pen_irq = gpio_to_irq(gpio_touch_irq);
196         irq_set_irq_type(wm->pen_irq, IRQ_TYPE_EDGE_BOTH);
197 
198         wm97xx_config_gpio(wm, WM97XX_GPIO_13, WM97XX_GPIO_IN,
199                            WM97XX_GPIO_POL_HIGH,
200                            WM97XX_GPIO_STICKY,
201                            WM97XX_GPIO_WAKE);
202         wm97xx_config_gpio(wm, WM97XX_GPIO_2, WM97XX_GPIO_OUT,
203                            WM97XX_GPIO_POL_HIGH,
204                            WM97XX_GPIO_NOTSTICKY,
205                            WM97XX_GPIO_NOWAKE);
206 
207         return wm97xx_register_mach_ops(wm, &zylonite_mach_ops);
208 }
209 
210 static int zylonite_wm97xx_remove(struct platform_device *pdev)
211 {
212         struct wm97xx *wm = platform_get_drvdata(pdev);
213 
214         wm97xx_unregister_mach_ops(wm);
215 
216         return 0;
217 }
218 
219 static struct platform_driver zylonite_wm97xx_driver = {
220         .probe  = zylonite_wm97xx_probe,
221         .remove = zylonite_wm97xx_remove,
222         .driver = {
223                 .name   = "wm97xx-touch",
224         },
225 };
226 module_platform_driver(zylonite_wm97xx_driver);
227 
228 /* Module information */
229 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
230 MODULE_DESCRIPTION("wm97xx continuous touch driver for Zylonite");
231 MODULE_LICENSE("GPL");
232 

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