linux/drivers/input/touchscreen/jornada720_ts.c
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   1/*
   2 * drivers/input/touchscreen/jornada720_ts.c
   3 *
   4 * Copyright (C) 2007 Kristoffer Ericson <Kristoffer.Ericson@gmail.com>
   5 *
   6 *  Copyright (C) 2006 Filip Zyzniewski <filip.zyzniewski@tefnet.pl>
   7 *  based on HP Jornada 56x touchscreen driver by Alex Lange <chicken@handhelds.org>
   8 *
   9 * This program is free software; you can redistribute it and/or modify
  10 * it under the terms of the GNU General Public License version 2 as
  11 * published by the Free Software Foundation.
  12 *
  13 * HP Jornada 710/720/729 Touchscreen Driver
  14 */
  15
  16#include <linux/platform_device.h>
  17#include <linux/init.h>
  18#include <linux/input.h>
  19#include <linux/interrupt.h>
  20#include <linux/module.h>
  21
  22#include <mach/hardware.h>
  23#include <mach/jornada720.h>
  24
  25MODULE_AUTHOR("Kristoffer Ericson <kristoffer.ericson@gmail.com>");
  26MODULE_DESCRIPTION("HP Jornada 710/720/728 touchscreen driver");
  27MODULE_LICENSE("GPL v2");
  28
  29struct jornada_ts {
  30        struct input_dev *dev;
  31        int x_data[4];          /* X sample values */
  32        int y_data[4];          /* Y sample values */
  33};
  34
  35static void jornada720_ts_collect_data(struct jornada_ts *jornada_ts)
  36{
  37
  38    /* 3 low word X samples */
  39    jornada_ts->x_data[0] = jornada_ssp_byte(TXDUMMY);
  40    jornada_ts->x_data[1] = jornada_ssp_byte(TXDUMMY);
  41    jornada_ts->x_data[2] = jornada_ssp_byte(TXDUMMY);
  42
  43    /* 3 low word Y samples */
  44    jornada_ts->y_data[0] = jornada_ssp_byte(TXDUMMY);
  45    jornada_ts->y_data[1] = jornada_ssp_byte(TXDUMMY);
  46    jornada_ts->y_data[2] = jornada_ssp_byte(TXDUMMY);
  47
  48    /* combined x samples bits */
  49    jornada_ts->x_data[3] = jornada_ssp_byte(TXDUMMY);
  50
  51    /* combined y samples bits */
  52    jornada_ts->y_data[3] = jornada_ssp_byte(TXDUMMY);
  53}
  54
  55static int jornada720_ts_average(int coords[4])
  56{
  57        int coord, high_bits = coords[3];
  58
  59        coord  = coords[0] | ((high_bits & 0x03) << 8);
  60        coord += coords[1] | ((high_bits & 0x0c) << 6);
  61        coord += coords[2] | ((high_bits & 0x30) << 4);
  62
  63        return coord / 3;
  64}
  65
  66static irqreturn_t jornada720_ts_interrupt(int irq, void *dev_id)
  67{
  68        struct platform_device *pdev = dev_id;
  69        struct jornada_ts *jornada_ts = platform_get_drvdata(pdev);
  70        struct input_dev *input = jornada_ts->dev;
  71        int x, y;
  72
  73        /* If GPIO_GPIO9 is set to high then report pen up */
  74        if (GPLR & GPIO_GPIO(9)) {
  75                input_report_key(input, BTN_TOUCH, 0);
  76                input_sync(input);
  77        } else {
  78                jornada_ssp_start();
  79
  80                /* proper reply to request is always TXDUMMY */
  81                if (jornada_ssp_inout(GETTOUCHSAMPLES) == TXDUMMY) {
  82                        jornada720_ts_collect_data(jornada_ts);
  83
  84                        x = jornada720_ts_average(jornada_ts->x_data);
  85                        y = jornada720_ts_average(jornada_ts->y_data);
  86
  87                        input_report_key(input, BTN_TOUCH, 1);
  88                        input_report_abs(input, ABS_X, x);
  89                        input_report_abs(input, ABS_Y, y);
  90                        input_sync(input);
  91                }
  92
  93                jornada_ssp_end();
  94        }
  95
  96        return IRQ_HANDLED;
  97}
  98
  99static int __devinit jornada720_ts_probe(struct platform_device *pdev)
 100{
 101        struct jornada_ts *jornada_ts;
 102        struct input_dev *input_dev;
 103        int error;
 104
 105        jornada_ts = kzalloc(sizeof(struct jornada_ts), GFP_KERNEL);
 106        input_dev = input_allocate_device();
 107
 108        if (!jornada_ts || !input_dev) {
 109                error = -ENOMEM;
 110                goto fail1;
 111        }
 112
 113        platform_set_drvdata(pdev, jornada_ts);
 114
 115        jornada_ts->dev = input_dev;
 116
 117        input_dev->name = "HP Jornada 7xx Touchscreen";
 118        input_dev->phys = "jornadats/input0";
 119        input_dev->id.bustype = BUS_HOST;
 120        input_dev->dev.parent = &pdev->dev;
 121
 122        input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
 123        input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
 124        input_set_abs_params(input_dev, ABS_X, 270, 3900, 0, 0);
 125        input_set_abs_params(input_dev, ABS_Y, 180, 3700, 0, 0);
 126
 127        error = request_irq(IRQ_GPIO9,
 128                        jornada720_ts_interrupt,
 129                        IRQF_DISABLED | IRQF_TRIGGER_RISING,
 130                        "HP7XX Touchscreen driver", pdev);
 131        if (error) {
 132                printk(KERN_INFO "HP7XX TS : Unable to acquire irq!\n");
 133                goto fail1;
 134        }
 135
 136        error = input_register_device(jornada_ts->dev);
 137        if (error)
 138                goto fail2;
 139
 140        return 0;
 141
 142 fail2:
 143        free_irq(IRQ_GPIO9, pdev);
 144 fail1:
 145        platform_set_drvdata(pdev, NULL);
 146        input_free_device(input_dev);
 147        kfree(jornada_ts);
 148        return error;
 149}
 150
 151static int __devexit jornada720_ts_remove(struct platform_device *pdev)
 152{
 153        struct jornada_ts *jornada_ts = platform_get_drvdata(pdev);
 154
 155        free_irq(IRQ_GPIO9, pdev);
 156        platform_set_drvdata(pdev, NULL);
 157        input_unregister_device(jornada_ts->dev);
 158        kfree(jornada_ts);
 159
 160        return 0;
 161}
 162
 163/* work with hotplug and coldplug */
 164MODULE_ALIAS("platform:jornada_ts");
 165
 166static struct platform_driver jornada720_ts_driver = {
 167        .probe          = jornada720_ts_probe,
 168        .remove         = __devexit_p(jornada720_ts_remove),
 169        .driver         = {
 170                .name   = "jornada_ts",
 171                .owner  = THIS_MODULE,
 172        },
 173};
 174
 175static int __init jornada720_ts_init(void)
 176{
 177        return platform_driver_register(&jornada720_ts_driver);
 178}
 179
 180static void __exit jornada720_ts_exit(void)
 181{
 182        platform_driver_unregister(&jornada720_ts_driver);
 183}
 184
 185module_init(jornada720_ts_init);
 186module_exit(jornada720_ts_exit);
 187