linux/drivers/input/touchscreen/mainstone-wm97xx.c
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   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * mainstone-wm97xx.c  --  Mainstone Continuous Touch screen driver for
   4 *                         Wolfson WM97xx AC97 Codecs.
   5 *
   6 * Copyright 2004, 2007 Wolfson Microelectronics PLC.
   7 * Author: Liam Girdwood <lrg@slimlogic.co.uk>
   8 * Parts Copyright : Ian Molton <spyro@f2s.com>
   9 *                   Andrew Zabolotny <zap@homelink.ru>
  10 *
  11 * Notes:
  12 *     This is a wm97xx extended touch driver to capture touch
  13 *     data in a continuous manner on the Intel XScale architecture
  14 *
  15 *  Features:
  16 *       - codecs supported:- WM9705, WM9712, WM9713
  17 *       - processors supported:- Intel XScale PXA25x, PXA26x, PXA27x
  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/irq.h>
  25#include <linux/interrupt.h>
  26#include <linux/wm97xx.h>
  27#include <linux/io.h>
  28#include <linux/gpio.h>
  29
  30#include <mach/regs-ac97.h>
  31
  32#include <asm/mach-types.h>
  33
  34struct 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
  43static const struct continuous cinfo[] = {
  44        {WM9705_ID2, 0, WM_READS(94), 94},
  45        {WM9705_ID2, 1, WM_READS(188), 188},
  46        {WM9705_ID2, 2, WM_READS(375), 375},
  47        {WM9705_ID2, 3, WM_READS(750), 750},
  48        {WM9712_ID2, 0, WM_READS(94), 94},
  49        {WM9712_ID2, 1, WM_READS(188), 188},
  50        {WM9712_ID2, 2, WM_READS(375), 375},
  51        {WM9712_ID2, 3, WM_READS(750), 750},
  52        {WM9713_ID2, 0, WM_READS(94), 94},
  53        {WM9713_ID2, 1, WM_READS(120), 120},
  54        {WM9713_ID2, 2, WM_READS(154), 154},
  55        {WM9713_ID2, 3, WM_READS(188), 188},
  56};
  57
  58/* continuous speed index */
  59static int sp_idx;
  60static u16 last, tries;
  61static int irq;
  62
  63/*
  64 * Pen sampling frequency (Hz) in continuous mode.
  65 */
  66static int cont_rate = 200;
  67module_param(cont_rate, int, 0);
  68MODULE_PARM_DESC(cont_rate, "Sampling rate in continuous mode (Hz)");
  69
  70/*
  71 * Pen down detection.
  72 *
  73 * This driver can either poll or use an interrupt to indicate a pen down
  74 * event. If the irq request fails then it will fall back to polling mode.
  75 */
  76static int pen_int;
  77module_param(pen_int, int, 0);
  78MODULE_PARM_DESC(pen_int, "Pen down detection (1 = interrupt, 0 = polling)");
  79
  80/*
  81 * Pressure readback.
  82 *
  83 * Set to 1 to read back pen down pressure
  84 */
  85static int pressure;
  86module_param(pressure, int, 0);
  87MODULE_PARM_DESC(pressure, "Pressure readback (1 = pressure, 0 = no pressure)");
  88
  89/*
  90 * AC97 touch data slot.
  91 *
  92 * Touch screen readback data ac97 slot
  93 */
  94static int ac97_touch_slot = 5;
  95module_param(ac97_touch_slot, int, 0);
  96MODULE_PARM_DESC(ac97_touch_slot, "Touch screen data slot AC97 number");
  97
  98
  99/* flush AC97 slot 5 FIFO on pxa machines */
 100#ifdef CONFIG_PXA27x
 101static void wm97xx_acc_pen_up(struct wm97xx *wm)
 102{
 103        schedule_timeout_uninterruptible(1);
 104
 105        while (MISR & (1 << 2))
 106                MODR;
 107}
 108#else
 109static void wm97xx_acc_pen_up(struct wm97xx *wm)
 110{
 111        unsigned int count;
 112
 113        schedule_timeout_uninterruptible(1);
 114
 115        for (count = 0; count < 16; count++)
 116                MODR;
 117}
 118#endif
 119
 120static int wm97xx_acc_pen_down(struct wm97xx *wm)
 121{
 122        u16 x, y, p = 0x100 | WM97XX_ADCSEL_PRES;
 123        int reads = 0;
 124
 125        /* When the AC97 queue has been drained we need to allow time
 126         * to buffer up samples otherwise we end up spinning polling
 127         * for samples.  The controller can't have a suitably low
 128         * threshold set to use the notifications it gives.
 129         */
 130        schedule_timeout_uninterruptible(1);
 131
 132        if (tries > 5) {
 133                tries = 0;
 134                return RC_PENUP;
 135        }
 136
 137        x = MODR;
 138        if (x == last) {
 139                tries++;
 140                return RC_AGAIN;
 141        }
 142        last = x;
 143        do {
 144                if (reads)
 145                        x = MODR;
 146                y = MODR;
 147                if (pressure)
 148                        p = MODR;
 149
 150                dev_dbg(wm->dev, "Raw coordinates: x=%x, y=%x, p=%x\n",
 151                        x, y, p);
 152
 153                /* are samples valid */
 154                if ((x & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_X ||
 155                    (y & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_Y ||
 156                    (p & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_PRES)
 157                        goto up;
 158
 159                /* coordinate is good */
 160                tries = 0;
 161                input_report_abs(wm->input_dev, ABS_X, x & 0xfff);
 162                input_report_abs(wm->input_dev, ABS_Y, y & 0xfff);
 163                input_report_abs(wm->input_dev, ABS_PRESSURE, p & 0xfff);
 164                input_report_key(wm->input_dev, BTN_TOUCH, (p != 0));
 165                input_sync(wm->input_dev);
 166                reads++;
 167        } while (reads < cinfo[sp_idx].reads);
 168up:
 169        return RC_PENDOWN | RC_AGAIN;
 170}
 171
 172static int wm97xx_acc_startup(struct wm97xx *wm)
 173{
 174        int idx = 0, ret = 0;
 175
 176        /* check we have a codec */
 177        if (wm->ac97 == NULL)
 178                return -ENODEV;
 179
 180        /* Go you big red fire engine */
 181        for (idx = 0; idx < ARRAY_SIZE(cinfo); idx++) {
 182                if (wm->id != cinfo[idx].id)
 183                        continue;
 184                sp_idx = idx;
 185                if (cont_rate <= cinfo[idx].speed)
 186                        break;
 187        }
 188        wm->acc_rate = cinfo[sp_idx].code;
 189        wm->acc_slot = ac97_touch_slot;
 190        dev_info(wm->dev,
 191                 "mainstone accelerated touchscreen driver, %d samples/sec\n",
 192                 cinfo[sp_idx].speed);
 193
 194        /* IRQ driven touchscreen is used on Palm hardware */
 195        if (machine_is_palmt5() || machine_is_palmtx() || machine_is_palmld()) {
 196                pen_int = 1;
 197                irq = 27;
 198                /* There is some obscure mutant of WM9712 interbred with WM9713
 199                 * used on Palm HW */
 200                wm->variant = WM97xx_WM1613;
 201        } else if (machine_is_mainstone() && pen_int)
 202                irq = 4;
 203
 204        if (irq) {
 205                ret = gpio_request(irq, "Touchscreen IRQ");
 206                if (ret)
 207                        goto out;
 208
 209                ret = gpio_direction_input(irq);
 210                if (ret) {
 211                        gpio_free(irq);
 212                        goto out;
 213                }
 214
 215                wm->pen_irq = gpio_to_irq(irq);
 216                irq_set_irq_type(wm->pen_irq, IRQ_TYPE_EDGE_BOTH);
 217        } else /* pen irq not supported */
 218                pen_int = 0;
 219
 220        /* codec specific irq config */
 221        if (pen_int) {
 222                switch (wm->id) {
 223                case WM9705_ID2:
 224                        break;
 225                case WM9712_ID2:
 226                case WM9713_ID2:
 227                        /* use PEN_DOWN GPIO 13 to assert IRQ on GPIO line 2 */
 228                        wm97xx_config_gpio(wm, WM97XX_GPIO_13, WM97XX_GPIO_IN,
 229                                           WM97XX_GPIO_POL_HIGH,
 230                                           WM97XX_GPIO_STICKY,
 231                                           WM97XX_GPIO_WAKE);
 232                        wm97xx_config_gpio(wm, WM97XX_GPIO_2, WM97XX_GPIO_OUT,
 233                                           WM97XX_GPIO_POL_HIGH,
 234                                           WM97XX_GPIO_NOTSTICKY,
 235                                           WM97XX_GPIO_NOWAKE);
 236                        break;
 237                default:
 238                        dev_err(wm->dev,
 239                                "pen down irq not supported on this device\n");
 240                        pen_int = 0;
 241                        break;
 242                }
 243        }
 244
 245out:
 246        return ret;
 247}
 248
 249static void wm97xx_acc_shutdown(struct wm97xx *wm)
 250{
 251        /* codec specific deconfig */
 252        if (pen_int) {
 253                if (irq)
 254                        gpio_free(irq);
 255                wm->pen_irq = 0;
 256        }
 257}
 258
 259static void wm97xx_irq_enable(struct wm97xx *wm, int enable)
 260{
 261        if (enable)
 262                enable_irq(wm->pen_irq);
 263        else
 264                disable_irq_nosync(wm->pen_irq);
 265}
 266
 267static struct wm97xx_mach_ops mainstone_mach_ops = {
 268        .acc_enabled = 1,
 269        .acc_pen_up = wm97xx_acc_pen_up,
 270        .acc_pen_down = wm97xx_acc_pen_down,
 271        .acc_startup = wm97xx_acc_startup,
 272        .acc_shutdown = wm97xx_acc_shutdown,
 273        .irq_enable = wm97xx_irq_enable,
 274        .irq_gpio = WM97XX_GPIO_2,
 275};
 276
 277static int mainstone_wm97xx_probe(struct platform_device *pdev)
 278{
 279        struct wm97xx *wm = platform_get_drvdata(pdev);
 280
 281        return wm97xx_register_mach_ops(wm, &mainstone_mach_ops);
 282}
 283
 284static int mainstone_wm97xx_remove(struct platform_device *pdev)
 285{
 286        struct wm97xx *wm = platform_get_drvdata(pdev);
 287
 288        wm97xx_unregister_mach_ops(wm);
 289        return 0;
 290}
 291
 292static struct platform_driver mainstone_wm97xx_driver = {
 293        .probe = mainstone_wm97xx_probe,
 294        .remove = mainstone_wm97xx_remove,
 295        .driver = {
 296                .name = "wm97xx-touch",
 297        },
 298};
 299module_platform_driver(mainstone_wm97xx_driver);
 300
 301/* Module information */
 302MODULE_AUTHOR("Liam Girdwood <lrg@slimlogic.co.uk>");
 303MODULE_DESCRIPTION("wm97xx continuous touch driver for mainstone");
 304MODULE_LICENSE("GPL");
 305
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