input/touchscreen/jornada720_ts.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * drivers/input/touchscreen/jornada720_ts.c
0004  *
0005  * Copyright (C) 2007 Kristoffer Ericson <Kristoffer.Ericson@gmail.com>
0006  *
0007  *  Copyright (C) 2006 Filip Zyzniewski <filip.zyzniewski@tefnet.pl>
0008  *  based on HP Jornada 56x touchscreen driver by Alex Lange <chicken@handhelds.org>
0009  *
0010  * HP Jornada 710/720/729 Touchscreen Driver
0011  */
0012
0013 #include <linux/gpio/consumer.h>
0014 #include <linux/platform_device.h>
0015 #include <linux/input.h>
0016 #include <linux/interrupt.h>
0017 #include <linux/module.h>
0018 #include <linux/slab.h>
0019 #include <linux/io.h>
0020
0021 #include <mach/jornada720.h>
0022
0023 MODULE_AUTHOR("Kristoffer Ericson <kristoffer.ericson@gmail.com>");
0024 MODULE_DESCRIPTION("HP Jornada 710/720/728 touchscreen driver");
0025 MODULE_LICENSE("GPL v2");
0026
0027 struct jornada_ts {
0028     struct input_dev *dev;
0029     struct gpio_desc *gpio;
0030     int x_data[4];      /* X sample values */
0031     int y_data[4];      /* Y sample values */
0032 };
0033
0034 static void jornada720_ts_collect_data(struct jornada_ts *jornada_ts)
0035 {
0036     /* 3 low word X samples */
0037     jornada_ts->x_data[0] = jornada_ssp_byte(TXDUMMY);
0038     jornada_ts->x_data[1] = jornada_ssp_byte(TXDUMMY);
0039     jornada_ts->x_data[2] = jornada_ssp_byte(TXDUMMY);
0040
0041     /* 3 low word Y samples */
0042     jornada_ts->y_data[0] = jornada_ssp_byte(TXDUMMY);
0043     jornada_ts->y_data[1] = jornada_ssp_byte(TXDUMMY);
0044     jornada_ts->y_data[2] = jornada_ssp_byte(TXDUMMY);
0045
0046     /* combined x samples bits */
0047     jornada_ts->x_data[3] = jornada_ssp_byte(TXDUMMY);
0048
0049     /* combined y samples bits */
0050     jornada_ts->y_data[3] = jornada_ssp_byte(TXDUMMY);
0051 }
0052
0053 static int jornada720_ts_average(int coords[4])
0054 {
0055     int coord, high_bits = coords[3];
0056
0057     coord  = coords[0] | ((high_bits & 0x03) << 8);
0058     coord += coords[1] | ((high_bits & 0x0c) << 6);
0059     coord += coords[2] | ((high_bits & 0x30) << 4);
0060
0061     return coord / 3;
0062 }
0063
0064 static irqreturn_t jornada720_ts_interrupt(int irq, void *dev_id)
0065 {
0066     struct platform_device *pdev = dev_id;
0067     struct jornada_ts *jornada_ts = platform_get_drvdata(pdev);
0068     struct input_dev *input = jornada_ts->dev;
0069     int x, y;
0070
0071     /* If gpio is high then report pen up */
0072     if (gpiod_get_value(jornada_ts->gpio)) {
0073         input_report_key(input, BTN_TOUCH, 0);
0074         input_sync(input);
0075     } else {
0076         jornada_ssp_start();
0077
0078         /* proper reply to request is always TXDUMMY */
0079         if (jornada_ssp_inout(GETTOUCHSAMPLES) == TXDUMMY) {
0080             jornada720_ts_collect_data(jornada_ts);
0081
0082             x = jornada720_ts_average(jornada_ts->x_data);
0083             y = jornada720_ts_average(jornada_ts->y_data);
0084
0085             input_report_key(input, BTN_TOUCH, 1);
0086             input_report_abs(input, ABS_X, x);
0087             input_report_abs(input, ABS_Y, y);
0088             input_sync(input);
0089         }
0090
0091         jornada_ssp_end();
0092     }
0093
0094     return IRQ_HANDLED;
0095 }
0096
0097 static int jornada720_ts_probe(struct platform_device *pdev)
0098 {
0099     struct jornada_ts *jornada_ts;
0100     struct input_dev *input_dev;
0101     int error, irq;
0102
0103     jornada_ts = devm_kzalloc(&pdev->dev, sizeof(*jornada_ts), GFP_KERNEL);
0104     if (!jornada_ts)
0105         return -ENOMEM;
0106
0107     input_dev = devm_input_allocate_device(&pdev->dev);
0108     if (!input_dev)
0109         return -ENOMEM;
0110
0111     platform_set_drvdata(pdev, jornada_ts);
0112
0113     jornada_ts->gpio = devm_gpiod_get(&pdev->dev, "penup", GPIOD_IN);
0114     if (IS_ERR(jornada_ts->gpio))
0115         return PTR_ERR(jornada_ts->gpio);
0116
0117     irq = gpiod_to_irq(jornada_ts->gpio);
0118     if (irq <= 0)
0119         return irq < 0 ? irq : -EINVAL;
0120
0121     jornada_ts->dev = input_dev;
0122
0123     input_dev->name = "HP Jornada 7xx Touchscreen";
0124     input_dev->phys = "jornadats/input0";
0125     input_dev->id.bustype = BUS_HOST;
0126     input_dev->dev.parent = &pdev->dev;
0127
0128     input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
0129     input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
0130     input_set_abs_params(input_dev, ABS_X, 270, 3900, 0, 0);
0131     input_set_abs_params(input_dev, ABS_Y, 180, 3700, 0, 0);
0132
0133     error = devm_request_irq(&pdev->dev, irq, jornada720_ts_interrupt,
0134                  IRQF_TRIGGER_RISING,
0135                  "HP7XX Touchscreen driver", pdev);
0136     if (error) {
0137         dev_err(&pdev->dev, "HP7XX TS : Unable to acquire irq!\n");
0138         return error;
0139     }
0140
0141     error = input_register_device(jornada_ts->dev);
0142     if (error)
0143         return error;
0144
0145     return 0;
0146 }
0147
0148 /* work with hotplug and coldplug */
0149 MODULE_ALIAS("platform:jornada_ts");
0150
0151 static struct platform_driver jornada720_ts_driver = {
0152     .probe      = jornada720_ts_probe,
0153     .driver     = {
0154         .name   = "jornada_ts",
0155     },
0156 };
0157 module_platform_driver(jornada720_ts_driver);