drivers/input/touchscreen/zylonite-wm97xx.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * zylonite-wm97xx.c  --  Zylonite Continuous Touch screen driver
   4  *
   5  * Copyright 2004, 2007, 2008 Wolfson Microelectronics PLC.
   6  * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
   7  * Parts Copyright : Ian Molton <spyro@f2s.com>
   8  *                   Andrew Zabolotny <zap@homelink.ru>
   9  *
  10  * Notes:
  11  *     This is a wm97xx extended touch driver supporting interrupt driven
  12  *     and continuous operation on Marvell Zylonite development systems
  13  *     (which have a WM9713 on board).
  14  */
  15
  16 #include <linux/module.h>
  17 #include <linux/moduleparam.h>
  18 #include <linux/kernel.h>
  19 #include <linux/delay.h>
  20 #include <linux/gpio.h>
  21 #include <linux/irq.h>
  22 #include <linux/interrupt.h>
  23 #include <linux/io.h>
  24 #include <linux/wm97xx.h>
  25
  26 #include <mach/hardware.h>
  27 #include <mach/mfp.h>
  28 #include <mach/regs-ac97.h>
  29
  30 struct continuous {
  31         u16 id;    /* codec id */
  32         u8 code;   /* continuous code */
  33         u8 reads;  /* number of coord reads per read cycle */
  34         u32 speed; /* number of coords per second */
  35 };
  36
  37 #define WM_READS(sp) ((sp / HZ) + 1)
  38
  39 static const struct continuous cinfo[] = {
  40         { WM9713_ID2, 0, WM_READS(94),  94  },
  41         { WM9713_ID2, 1, WM_READS(120), 120 },
  42         { WM9713_ID2, 2, WM_READS(154), 154 },
  43         { WM9713_ID2, 3, WM_READS(188), 188 },
  44 };
  45
  46 /* continuous speed index */
  47 static int sp_idx;
  48
  49 /*
  50  * Pen sampling frequency (Hz) in continuous mode.
  51  */
  52 static int cont_rate = 200;
  53 module_param(cont_rate, int, 0);
  54 MODULE_PARM_DESC(cont_rate, "Sampling rate in continuous mode (Hz)");
  55
  56 /*
  57  * Pressure readback.
  58  *
  59  * Set to 1 to read back pen down pressure
  60  */
  61 static int pressure;
  62 module_param(pressure, int, 0);
  63 MODULE_PARM_DESC(pressure, "Pressure readback (1 = pressure, 0 = no pressure)");
  64
  65 /*
  66  * AC97 touch data slot.
  67  *
  68  * Touch screen readback data ac97 slot
  69  */
  70 static int ac97_touch_slot = 5;
  71 module_param(ac97_touch_slot, int, 0);
  72 MODULE_PARM_DESC(ac97_touch_slot, "Touch screen data slot AC97 number");
  73
  74
  75 /* flush AC97 slot 5 FIFO machines */
  76 static void wm97xx_acc_pen_up(struct wm97xx *wm)
  77 {
  78         int i;
  79
  80         msleep(1);
  81
  82         for (i = 0; i < 16; i++)
  83                 MODR;
  84 }
  85
  86 static int wm97xx_acc_pen_down(struct wm97xx *wm)
  87 {
  88         u16 x, y, p = 0x100 | WM97XX_ADCSEL_PRES;
  89         int reads = 0;
  90         static u16 last, tries;
  91
  92         /* When the AC97 queue has been drained we need to allow time
  93          * to buffer up samples otherwise we end up spinning polling
  94          * for samples.  The controller can't have a suitably low
  95          * threshold set to use the notifications it gives.
  96          */
  97         msleep(1);
  98
  99         if (tries > 5) {
 100                 tries = 0;
 101                 return RC_PENUP;
 102         }
 103
 104         x = MODR;
 105         if (x == last) {
 106                 tries++;
 107                 return RC_AGAIN;
 108         }
 109         last = x;
 110         do {
 111                 if (reads)
 112                         x = MODR;
 113                 y = MODR;
 114                 if (pressure)
 115                         p = MODR;
 116
 117                 dev_dbg(wm->dev, "Raw coordinates: x=%x, y=%x, p=%x\n",
 118                         x, y, p);
 119
 120                 /* are samples valid */
 121                 if ((x & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_X ||
 122                     (y & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_Y ||
 123                     (p & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_PRES)
 124                         goto up;
 125
 126                 /* coordinate is good */
 127                 tries = 0;
 128                 input_report_abs(wm->input_dev, ABS_X, x & 0xfff);
 129                 input_report_abs(wm->input_dev, ABS_Y, y & 0xfff);
 130                 input_report_abs(wm->input_dev, ABS_PRESSURE, p & 0xfff);
 131                 input_report_key(wm->input_dev, BTN_TOUCH, (p != 0));
 132                 input_sync(wm->input_dev);
 133                 reads++;
 134         } while (reads < cinfo[sp_idx].reads);
 135 up:
 136         return RC_PENDOWN | RC_AGAIN;
 137 }
 138
 139 static int wm97xx_acc_startup(struct wm97xx *wm)
 140 {
 141         int idx;
 142
 143         /* check we have a codec */
 144         if (wm->ac97 == NULL)
 145                 return -ENODEV;
 146
 147         /* Go you big red fire engine */
 148         for (idx = 0; idx < ARRAY_SIZE(cinfo); idx++) {
 149                 if (wm->id != cinfo[idx].id)
 150                         continue;
 151                 sp_idx = idx;
 152                 if (cont_rate <= cinfo[idx].speed)
 153                         break;
 154         }
 155         wm->acc_rate = cinfo[sp_idx].code;
 156         wm->acc_slot = ac97_touch_slot;
 157         dev_info(wm->dev,
 158                  "zylonite accelerated touchscreen driver, %d samples/sec\n",
 159                  cinfo[sp_idx].speed);
 160
 161         return 0;
 162 }
 163
 164 static void wm97xx_irq_enable(struct wm97xx *wm, int enable)
 165 {
 166         if (enable)
 167                 enable_irq(wm->pen_irq);
 168         else
 169                 disable_irq_nosync(wm->pen_irq);
 170 }
 171
 172 static struct wm97xx_mach_ops zylonite_mach_ops = {
 173         .acc_enabled    = 1,
 174         .acc_pen_up     = wm97xx_acc_pen_up,
 175         .acc_pen_down   = wm97xx_acc_pen_down,
 176         .acc_startup    = wm97xx_acc_startup,
 177         .irq_enable     = wm97xx_irq_enable,
 178         .irq_gpio       = WM97XX_GPIO_2,
 179 };
 180
 181 static int zylonite_wm97xx_probe(struct platform_device *pdev)
 182 {
 183         struct wm97xx *wm = platform_get_drvdata(pdev);
 184         int gpio_touch_irq;
 185
 186         if (cpu_is_pxa320())
 187                 gpio_touch_irq = mfp_to_gpio(MFP_PIN_GPIO15);
 188         else
 189                 gpio_touch_irq = mfp_to_gpio(MFP_PIN_GPIO26);
 190
 191         wm->pen_irq = gpio_to_irq(gpio_touch_irq);
 192         irq_set_irq_type(wm->pen_irq, IRQ_TYPE_EDGE_BOTH);
 193
 194         wm97xx_config_gpio(wm, WM97XX_GPIO_13, WM97XX_GPIO_IN,
 195                            WM97XX_GPIO_POL_HIGH,
 196                            WM97XX_GPIO_STICKY,
 197                            WM97XX_GPIO_WAKE);
 198         wm97xx_config_gpio(wm, WM97XX_GPIO_2, WM97XX_GPIO_OUT,
 199                            WM97XX_GPIO_POL_HIGH,
 200                            WM97XX_GPIO_NOTSTICKY,
 201                            WM97XX_GPIO_NOWAKE);
 202
 203         return wm97xx_register_mach_ops(wm, &zylonite_mach_ops);
 204 }
 205
 206 static int zylonite_wm97xx_remove(struct platform_device *pdev)
 207 {
 208         struct wm97xx *wm = platform_get_drvdata(pdev);
 209
 210         wm97xx_unregister_mach_ops(wm);
 211
 212         return 0;
 213 }
 214
 215 static struct platform_driver zylonite_wm97xx_driver = {
 216         .probe  = zylonite_wm97xx_probe,
 217         .remove = zylonite_wm97xx_remove,
 218         .driver = {
 219                 .name   = "wm97xx-touch",
 220         },
 221 };
 222 module_platform_driver(zylonite_wm97xx_driver);
 223
 224 /* Module information */
 225 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
 226 MODULE_DESCRIPTION("wm97xx continuous touch driver for Zylonite");
 227 MODULE_LICENSE("GPL");