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Linux/drivers/input/touchscreen/pcap_ts.c

  1 /*
  2  * Driver for Motorola PCAP2 touchscreen as found in the EZX phone platform.
  3  *
  4  *  Copyright (C) 2006 Harald Welte <laforge@openezx.org>
  5  *  Copyright (C) 2009 Daniel Ribeiro <drwyrm@gmail.com>
  6  *
  7  *  This program is free software; you can redistribute it and/or modify
  8  *  it under the terms of the GNU General Public License version 2 as
  9  *  published by the Free Software Foundation.
 10  *
 11  */
 12 
 13 #include <linux/module.h>
 14 #include <linux/fs.h>
 15 #include <linux/string.h>
 16 #include <linux/slab.h>
 17 #include <linux/pm.h>
 18 #include <linux/timer.h>
 19 #include <linux/interrupt.h>
 20 #include <linux/platform_device.h>
 21 #include <linux/input.h>
 22 #include <linux/mfd/ezx-pcap.h>
 23 
 24 struct pcap_ts {
 25         struct pcap_chip *pcap;
 26         struct input_dev *input;
 27         struct delayed_work work;
 28         u16 x, y;
 29         u16 pressure;
 30         u8 read_state;
 31 };
 32 
 33 #define SAMPLE_DELAY    20 /* msecs */
 34 
 35 #define X_AXIS_MIN      0
 36 #define X_AXIS_MAX      1023
 37 #define Y_AXIS_MAX      X_AXIS_MAX
 38 #define Y_AXIS_MIN      X_AXIS_MIN
 39 #define PRESSURE_MAX    X_AXIS_MAX
 40 #define PRESSURE_MIN    X_AXIS_MIN
 41 
 42 static void pcap_ts_read_xy(void *data, u16 res[2])
 43 {
 44         struct pcap_ts *pcap_ts = data;
 45 
 46         switch (pcap_ts->read_state) {
 47         case PCAP_ADC_TS_M_PRESSURE:
 48                 /* pressure reading is unreliable */
 49                 if (res[0] > PRESSURE_MIN && res[0] < PRESSURE_MAX)
 50                         pcap_ts->pressure = res[0];
 51                 pcap_ts->read_state = PCAP_ADC_TS_M_XY;
 52                 schedule_delayed_work(&pcap_ts->work, 0);
 53                 break;
 54         case PCAP_ADC_TS_M_XY:
 55                 pcap_ts->y = res[0];
 56                 pcap_ts->x = res[1];
 57                 if (pcap_ts->x <= X_AXIS_MIN || pcap_ts->x >= X_AXIS_MAX ||
 58                     pcap_ts->y <= Y_AXIS_MIN || pcap_ts->y >= Y_AXIS_MAX) {
 59                         /* pen has been released */
 60                         input_report_abs(pcap_ts->input, ABS_PRESSURE, 0);
 61                         input_report_key(pcap_ts->input, BTN_TOUCH, 0);
 62 
 63                         pcap_ts->read_state = PCAP_ADC_TS_M_STANDBY;
 64                         schedule_delayed_work(&pcap_ts->work, 0);
 65                 } else {
 66                         /* pen is touching the screen */
 67                         input_report_abs(pcap_ts->input, ABS_X, pcap_ts->x);
 68                         input_report_abs(pcap_ts->input, ABS_Y, pcap_ts->y);
 69                         input_report_key(pcap_ts->input, BTN_TOUCH, 1);
 70                         input_report_abs(pcap_ts->input, ABS_PRESSURE,
 71                                                 pcap_ts->pressure);
 72 
 73                         /* switch back to pressure read mode */
 74                         pcap_ts->read_state = PCAP_ADC_TS_M_PRESSURE;
 75                         schedule_delayed_work(&pcap_ts->work,
 76                                         msecs_to_jiffies(SAMPLE_DELAY));
 77                 }
 78                 input_sync(pcap_ts->input);
 79                 break;
 80         default:
 81                 dev_warn(&pcap_ts->input->dev,
 82                                 "pcap_ts: Warning, unhandled read_state %d\n",
 83                                 pcap_ts->read_state);
 84                 break;
 85         }
 86 }
 87 
 88 static void pcap_ts_work(struct work_struct *work)
 89 {
 90         struct delayed_work *dw = container_of(work, struct delayed_work, work);
 91         struct pcap_ts *pcap_ts = container_of(dw, struct pcap_ts, work);
 92         u8 ch[2];
 93 
 94         pcap_set_ts_bits(pcap_ts->pcap,
 95                         pcap_ts->read_state << PCAP_ADC_TS_M_SHIFT);
 96 
 97         if (pcap_ts->read_state == PCAP_ADC_TS_M_STANDBY)
 98                 return;
 99 
100         /* start adc conversion */
101         ch[0] = PCAP_ADC_CH_TS_X1;
102         ch[1] = PCAP_ADC_CH_TS_Y1;
103         pcap_adc_async(pcap_ts->pcap, PCAP_ADC_BANK_1, 0, ch,
104                                                 pcap_ts_read_xy, pcap_ts);
105 }
106 
107 static irqreturn_t pcap_ts_event_touch(int pirq, void *data)
108 {
109         struct pcap_ts *pcap_ts = data;
110 
111         if (pcap_ts->read_state == PCAP_ADC_TS_M_STANDBY) {
112                 pcap_ts->read_state = PCAP_ADC_TS_M_PRESSURE;
113                 schedule_delayed_work(&pcap_ts->work, 0);
114         }
115         return IRQ_HANDLED;
116 }
117 
118 static int pcap_ts_open(struct input_dev *dev)
119 {
120         struct pcap_ts *pcap_ts = input_get_drvdata(dev);
121 
122         pcap_ts->read_state = PCAP_ADC_TS_M_STANDBY;
123         schedule_delayed_work(&pcap_ts->work, 0);
124 
125         return 0;
126 }
127 
128 static void pcap_ts_close(struct input_dev *dev)
129 {
130         struct pcap_ts *pcap_ts = input_get_drvdata(dev);
131 
132         cancel_delayed_work_sync(&pcap_ts->work);
133 
134         pcap_ts->read_state = PCAP_ADC_TS_M_NONTS;
135         pcap_set_ts_bits(pcap_ts->pcap,
136                                 pcap_ts->read_state << PCAP_ADC_TS_M_SHIFT);
137 }
138 
139 static int pcap_ts_probe(struct platform_device *pdev)
140 {
141         struct input_dev *input_dev;
142         struct pcap_ts *pcap_ts;
143         int err = -ENOMEM;
144 
145         pcap_ts = kzalloc(sizeof(*pcap_ts), GFP_KERNEL);
146         if (!pcap_ts)
147                 return err;
148 
149         pcap_ts->pcap = dev_get_drvdata(pdev->dev.parent);
150         platform_set_drvdata(pdev, pcap_ts);
151 
152         input_dev = input_allocate_device();
153         if (!input_dev)
154                 goto fail;
155 
156         INIT_DELAYED_WORK(&pcap_ts->work, pcap_ts_work);
157 
158         pcap_ts->read_state = PCAP_ADC_TS_M_NONTS;
159         pcap_set_ts_bits(pcap_ts->pcap,
160                                 pcap_ts->read_state << PCAP_ADC_TS_M_SHIFT);
161 
162         pcap_ts->input = input_dev;
163         input_set_drvdata(input_dev, pcap_ts);
164 
165         input_dev->name = "pcap-touchscreen";
166         input_dev->phys = "pcap_ts/input0";
167         input_dev->id.bustype = BUS_HOST;
168         input_dev->id.vendor = 0x0001;
169         input_dev->id.product = 0x0002;
170         input_dev->id.version = 0x0100;
171         input_dev->dev.parent = &pdev->dev;
172         input_dev->open = pcap_ts_open;
173         input_dev->close = pcap_ts_close;
174 
175         input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
176         input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
177         input_set_abs_params(input_dev, ABS_X, X_AXIS_MIN, X_AXIS_MAX, 0, 0);
178         input_set_abs_params(input_dev, ABS_Y, Y_AXIS_MIN, Y_AXIS_MAX, 0, 0);
179         input_set_abs_params(input_dev, ABS_PRESSURE, PRESSURE_MIN,
180                              PRESSURE_MAX, 0, 0);
181 
182         err = input_register_device(pcap_ts->input);
183         if (err)
184                 goto fail_allocate;
185 
186         err = request_irq(pcap_to_irq(pcap_ts->pcap, PCAP_IRQ_TS),
187                         pcap_ts_event_touch, 0, "Touch Screen", pcap_ts);
188         if (err)
189                 goto fail_register;
190 
191         return 0;
192 
193 fail_register:
194         input_unregister_device(input_dev);
195         goto fail;
196 fail_allocate:
197         input_free_device(input_dev);
198 fail:
199         kfree(pcap_ts);
200 
201         return err;
202 }
203 
204 static int pcap_ts_remove(struct platform_device *pdev)
205 {
206         struct pcap_ts *pcap_ts = platform_get_drvdata(pdev);
207 
208         free_irq(pcap_to_irq(pcap_ts->pcap, PCAP_IRQ_TS), pcap_ts);
209         cancel_delayed_work_sync(&pcap_ts->work);
210 
211         input_unregister_device(pcap_ts->input);
212 
213         kfree(pcap_ts);
214 
215         return 0;
216 }
217 
218 #ifdef CONFIG_PM
219 static int pcap_ts_suspend(struct device *dev)
220 {
221         struct pcap_ts *pcap_ts = dev_get_drvdata(dev);
222 
223         pcap_set_ts_bits(pcap_ts->pcap, PCAP_ADC_TS_REF_LOWPWR);
224         return 0;
225 }
226 
227 static int pcap_ts_resume(struct device *dev)
228 {
229         struct pcap_ts *pcap_ts = dev_get_drvdata(dev);
230 
231         pcap_set_ts_bits(pcap_ts->pcap,
232                                 pcap_ts->read_state << PCAP_ADC_TS_M_SHIFT);
233         return 0;
234 }
235 
236 static const struct dev_pm_ops pcap_ts_pm_ops = {
237         .suspend        = pcap_ts_suspend,
238         .resume         = pcap_ts_resume,
239 };
240 #define PCAP_TS_PM_OPS (&pcap_ts_pm_ops)
241 #else
242 #define PCAP_TS_PM_OPS NULL
243 #endif
244 
245 static struct platform_driver pcap_ts_driver = {
246         .probe          = pcap_ts_probe,
247         .remove         = pcap_ts_remove,
248         .driver         = {
249                 .name   = "pcap-ts",
250                 .owner  = THIS_MODULE,
251                 .pm     = PCAP_TS_PM_OPS,
252         },
253 };
254 module_platform_driver(pcap_ts_driver);
255 
256 MODULE_DESCRIPTION("Motorola PCAP2 touchscreen driver");
257 MODULE_AUTHOR("Daniel Ribeiro / Harald Welte");
258 MODULE_LICENSE("GPL");
259 MODULE_ALIAS("platform:pcap_ts");
260 

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