drivers/input/touchscreen/jornada720_ts.c

   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/gpio/consumer.h>
  17 #include <linux/platform_device.h>
  18 #include <linux/input.h>
  19 #include <linux/interrupt.h>
  20 #include <linux/module.h>
  21 #include <linux/slab.h>
  22 #include <linux/io.h>
  23
  24 #include <mach/jornada720.h>
  25
  26 MODULE_AUTHOR("Kristoffer Ericson <kristoffer.ericson@gmail.com>");
  27 MODULE_DESCRIPTION("HP Jornada 710/720/728 touchscreen driver");
  28 MODULE_LICENSE("GPL v2");
  29
  30 struct jornada_ts {
  31         struct input_dev *dev;
  32         struct gpio_desc *gpio;
  33         int x_data[4];          /* X sample values */
  34         int y_data[4];          /* Y sample values */
  35 };
  36
  37 static void jornada720_ts_collect_data(struct jornada_ts *jornada_ts)
  38 {
  39         /* 3 low word X samples */
  40         jornada_ts->x_data[0] = jornada_ssp_byte(TXDUMMY);
  41         jornada_ts->x_data[1] = jornada_ssp_byte(TXDUMMY);
  42         jornada_ts->x_data[2] = jornada_ssp_byte(TXDUMMY);
  43
  44         /* 3 low word Y samples */
  45         jornada_ts->y_data[0] = jornada_ssp_byte(TXDUMMY);
  46         jornada_ts->y_data[1] = jornada_ssp_byte(TXDUMMY);
  47         jornada_ts->y_data[2] = jornada_ssp_byte(TXDUMMY);
  48
  49         /* combined x samples bits */
  50         jornada_ts->x_data[3] = jornada_ssp_byte(TXDUMMY);
  51
  52         /* combined y samples bits */
  53         jornada_ts->y_data[3] = jornada_ssp_byte(TXDUMMY);
  54 }
  55
  56 static int jornada720_ts_average(int coords[4])
  57 {
  58         int coord, high_bits = coords[3];
  59
  60         coord  = coords[0] | ((high_bits & 0x03) << 8);
  61         coord += coords[1] | ((high_bits & 0x0c) << 6);
  62         coord += coords[2] | ((high_bits & 0x30) << 4);
  63
  64         return coord / 3;
  65 }
  66
  67 static irqreturn_t jornada720_ts_interrupt(int irq, void *dev_id)
  68 {
  69         struct platform_device *pdev = dev_id;
  70         struct jornada_ts *jornada_ts = platform_get_drvdata(pdev);
  71         struct input_dev *input = jornada_ts->dev;
  72         int x, y;
  73
  74         /* If gpio is high then report pen up */
  75         if (gpiod_get_value(jornada_ts->gpio)) {
  76                 input_report_key(input, BTN_TOUCH, 0);
  77                 input_sync(input);
  78         } else {
  79                 jornada_ssp_start();
  80
  81                 /* proper reply to request is always TXDUMMY */
  82                 if (jornada_ssp_inout(GETTOUCHSAMPLES) == TXDUMMY) {
  83                         jornada720_ts_collect_data(jornada_ts);
  84
  85                         x = jornada720_ts_average(jornada_ts->x_data);
  86                         y = jornada720_ts_average(jornada_ts->y_data);
  87
  88                         input_report_key(input, BTN_TOUCH, 1);
  89                         input_report_abs(input, ABS_X, x);
  90                         input_report_abs(input, ABS_Y, y);
  91                         input_sync(input);
  92                 }
  93
  94                 jornada_ssp_end();
  95         }
  96
  97         return IRQ_HANDLED;
  98 }
  99
 100 static int jornada720_ts_probe(struct platform_device *pdev)
 101 {
 102         struct jornada_ts *jornada_ts;
 103         struct input_dev *input_dev;
 104         int error, irq;
 105
 106         jornada_ts = devm_kzalloc(&pdev->dev, sizeof(*jornada_ts), GFP_KERNEL);
 107         if (!jornada_ts)
 108                 return -ENOMEM;
 109
 110         input_dev = devm_input_allocate_device(&pdev->dev);
 111         if (!input_dev)
 112                 return -ENOMEM;
 113
 114         platform_set_drvdata(pdev, jornada_ts);
 115
 116         jornada_ts->gpio = devm_gpiod_get(&pdev->dev, "penup", GPIOD_IN);
 117         if (IS_ERR(jornada_ts->gpio))
 118                 return PTR_ERR(jornada_ts->gpio);
 119
 120         irq = gpiod_to_irq(jornada_ts->gpio);
 121         if (irq <= 0)
 122                 return irq < 0 ? irq : -EINVAL;
 123
 124         jornada_ts->dev = input_dev;
 125
 126         input_dev->name = "HP Jornada 7xx Touchscreen";
 127         input_dev->phys = "jornadats/input0";
 128         input_dev->id.bustype = BUS_HOST;
 129         input_dev->dev.parent = &pdev->dev;
 130
 131         input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
 132         input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
 133         input_set_abs_params(input_dev, ABS_X, 270, 3900, 0, 0);
 134         input_set_abs_params(input_dev, ABS_Y, 180, 3700, 0, 0);
 135
 136         error = devm_request_irq(&pdev->dev, irq, jornada720_ts_interrupt,
 137                                  IRQF_TRIGGER_RISING,
 138                                  "HP7XX Touchscreen driver", pdev);
 139         if (error) {
 140                 dev_err(&pdev->dev, "HP7XX TS : Unable to acquire irq!\n");
 141                 return error;
 142         }
 143
 144         error = input_register_device(jornada_ts->dev);
 145         if (error)
 146                 return error;
 147
 148         return 0;
 149 }
 150
 151 /* work with hotplug and coldplug */
 152 MODULE_ALIAS("platform:jornada_ts");
 153
 154 static struct platform_driver jornada720_ts_driver = {
 155         .probe          = jornada720_ts_probe,
 156         .driver         = {
 157                 .name   = "jornada_ts",
 158         },
 159 };
 160 module_platform_driver(jornada720_ts_driver);