1 /* 2 * Driver for the Freescale Semiconductor MC13783 touchscreen. 3 * 4 * Copyright 2004-2007 Freescale Semiconductor, Inc. All Rights Reserved. 5 * Copyright (C) 2009 Sascha Hauer, Pengutronix 6 * 7 * Initial development of this code was funded by 8 * Phytec Messtechnik GmbH, http://www.phytec.de/ 9 * 10 * This program is free software; you can redistribute it and/or modify it 11 * under the terms of the GNU General Public License version 2 as published by 12 * the Free Software Foundation. 13 */ 14 #include <linux/platform_device.h> 15 #include <linux/mfd/mc13783.h> 16 #include <linux/kernel.h> 17 #include <linux/module.h> 18 #include <linux/input.h> 19 #include <linux/sched.h> 20 #include <linux/slab.h> 21 #include <linux/init.h> 22 23 #define MC13783_TS_NAME "mc13783-ts" 24 25 #define DEFAULT_SAMPLE_TOLERANCE 300 26 27 static unsigned int sample_tolerance = DEFAULT_SAMPLE_TOLERANCE; 28 module_param(sample_tolerance, uint, S_IRUGO | S_IWUSR); 29 MODULE_PARM_DESC(sample_tolerance, 30 "If the minimal and maximal value read out for one axis (out " 31 "of three) differ by this value (default: " 32 __stringify(DEFAULT_SAMPLE_TOLERANCE) ") or more, the reading " 33 "is supposed to be wrong and is discarded. Set to 0 to " 34 "disable this check."); 35 36 struct mc13783_ts_priv { 37 struct input_dev *idev; 38 struct mc13xxx *mc13xxx; 39 struct delayed_work work; 40 struct workqueue_struct *workq; 41 unsigned int sample[4]; 42 struct mc13xxx_ts_platform_data *touch; 43 }; 44 45 static irqreturn_t mc13783_ts_handler(int irq, void *data) 46 { 47 struct mc13783_ts_priv *priv = data; 48 49 mc13xxx_irq_ack(priv->mc13xxx, irq); 50 51 /* 52 * Kick off reading coordinates. Note that if work happens already 53 * be queued for future execution (it rearms itself) it will not 54 * be rescheduled for immediate execution here. However the rearm 55 * delay is HZ / 50 which is acceptable. 56 */ 57 queue_delayed_work(priv->workq, &priv->work, 0); 58 59 return IRQ_HANDLED; 60 } 61 62 #define sort3(a0, a1, a2) ({ \ 63 if (a0 > a1) \ 64 swap(a0, a1); \ 65 if (a1 > a2) \ 66 swap(a1, a2); \ 67 if (a0 > a1) \ 68 swap(a0, a1); \ 69 }) 70 71 static void mc13783_ts_report_sample(struct mc13783_ts_priv *priv) 72 { 73 struct input_dev *idev = priv->idev; 74 int x0, x1, x2, y0, y1, y2; 75 int cr0, cr1; 76 77 /* 78 * the values are 10-bit wide only, but the two least significant 79 * bits are for future 12 bit use and reading yields 0 80 */ 81 x0 = priv->sample[0] & 0xfff; 82 x1 = priv->sample[1] & 0xfff; 83 x2 = priv->sample[2] & 0xfff; 84 y0 = priv->sample[3] & 0xfff; 85 y1 = (priv->sample[0] >> 12) & 0xfff; 86 y2 = (priv->sample[1] >> 12) & 0xfff; 87 cr0 = (priv->sample[2] >> 12) & 0xfff; 88 cr1 = (priv->sample[3] >> 12) & 0xfff; 89 90 dev_dbg(&idev->dev, 91 "x: (% 4d,% 4d,% 4d) y: (% 4d, % 4d,% 4d) cr: (% 4d, % 4d)\n", 92 x0, x1, x2, y0, y1, y2, cr0, cr1); 93 94 sort3(x0, x1, x2); 95 sort3(y0, y1, y2); 96 97 cr0 = (cr0 + cr1) / 2; 98 99 if (!cr0 || !sample_tolerance || 100 (x2 - x0 < sample_tolerance && 101 y2 - y0 < sample_tolerance)) { 102 /* report the median coordinate and average pressure */ 103 if (cr0) { 104 input_report_abs(idev, ABS_X, x1); 105 input_report_abs(idev, ABS_Y, y1); 106 107 dev_dbg(&idev->dev, "report (%d, %d, %d)\n", 108 x1, y1, 0x1000 - cr0); 109 queue_delayed_work(priv->workq, &priv->work, HZ / 50); 110 } else 111 dev_dbg(&idev->dev, "report release\n"); 112 113 input_report_abs(idev, ABS_PRESSURE, 114 cr0 ? 0x1000 - cr0 : cr0); 115 input_report_key(idev, BTN_TOUCH, cr0); 116 input_sync(idev); 117 } else 118 dev_dbg(&idev->dev, "discard event\n"); 119 } 120 121 static void mc13783_ts_work(struct work_struct *work) 122 { 123 struct mc13783_ts_priv *priv = 124 container_of(work, struct mc13783_ts_priv, work.work); 125 unsigned int mode = MC13XXX_ADC_MODE_TS; 126 unsigned int channel = 12; 127 128 if (mc13xxx_adc_do_conversion(priv->mc13xxx, 129 mode, channel, 130 priv->touch->ato, priv->touch->atox, 131 priv->sample) == 0) 132 mc13783_ts_report_sample(priv); 133 } 134 135 static int mc13783_ts_open(struct input_dev *dev) 136 { 137 struct mc13783_ts_priv *priv = input_get_drvdata(dev); 138 int ret; 139 140 mc13xxx_lock(priv->mc13xxx); 141 142 mc13xxx_irq_ack(priv->mc13xxx, MC13XXX_IRQ_TS); 143 144 ret = mc13xxx_irq_request(priv->mc13xxx, MC13XXX_IRQ_TS, 145 mc13783_ts_handler, MC13783_TS_NAME, priv); 146 if (ret) 147 goto out; 148 149 ret = mc13xxx_reg_rmw(priv->mc13xxx, MC13XXX_ADC0, 150 MC13XXX_ADC0_TSMOD_MASK, MC13XXX_ADC0_TSMOD0); 151 if (ret) 152 mc13xxx_irq_free(priv->mc13xxx, MC13XXX_IRQ_TS, priv); 153 out: 154 mc13xxx_unlock(priv->mc13xxx); 155 return ret; 156 } 157 158 static void mc13783_ts_close(struct input_dev *dev) 159 { 160 struct mc13783_ts_priv *priv = input_get_drvdata(dev); 161 162 mc13xxx_lock(priv->mc13xxx); 163 mc13xxx_reg_rmw(priv->mc13xxx, MC13XXX_ADC0, 164 MC13XXX_ADC0_TSMOD_MASK, 0); 165 mc13xxx_irq_free(priv->mc13xxx, MC13XXX_IRQ_TS, priv); 166 mc13xxx_unlock(priv->mc13xxx); 167 168 cancel_delayed_work_sync(&priv->work); 169 } 170 171 static int __init mc13783_ts_probe(struct platform_device *pdev) 172 { 173 struct mc13783_ts_priv *priv; 174 struct input_dev *idev; 175 int ret = -ENOMEM; 176 177 priv = kzalloc(sizeof(*priv), GFP_KERNEL); 178 idev = input_allocate_device(); 179 if (!priv || !idev) 180 goto err_free_mem; 181 182 INIT_DELAYED_WORK(&priv->work, mc13783_ts_work); 183 priv->mc13xxx = dev_get_drvdata(pdev->dev.parent); 184 priv->idev = idev; 185 priv->touch = dev_get_platdata(&pdev->dev); 186 if (!priv->touch) { 187 dev_err(&pdev->dev, "missing platform data\n"); 188 ret = -ENODEV; 189 goto err_free_mem; 190 } 191 192 /* 193 * We need separate workqueue because mc13783_adc_do_conversion 194 * uses keventd and thus would deadlock. 195 */ 196 priv->workq = create_singlethread_workqueue("mc13783_ts"); 197 if (!priv->workq) 198 goto err_free_mem; 199 200 idev->name = MC13783_TS_NAME; 201 idev->dev.parent = &pdev->dev; 202 203 idev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS); 204 idev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH); 205 input_set_abs_params(idev, ABS_X, 0, 0xfff, 0, 0); 206 input_set_abs_params(idev, ABS_Y, 0, 0xfff, 0, 0); 207 input_set_abs_params(idev, ABS_PRESSURE, 0, 0xfff, 0, 0); 208 209 idev->open = mc13783_ts_open; 210 idev->close = mc13783_ts_close; 211 212 input_set_drvdata(idev, priv); 213 214 ret = input_register_device(priv->idev); 215 if (ret) { 216 dev_err(&pdev->dev, 217 "register input device failed with %d\n", ret); 218 goto err_destroy_wq; 219 } 220 221 platform_set_drvdata(pdev, priv); 222 return 0; 223 224 err_destroy_wq: 225 destroy_workqueue(priv->workq); 226 err_free_mem: 227 input_free_device(idev); 228 kfree(priv); 229 return ret; 230 } 231 232 static int mc13783_ts_remove(struct platform_device *pdev) 233 { 234 struct mc13783_ts_priv *priv = platform_get_drvdata(pdev); 235 236 destroy_workqueue(priv->workq); 237 input_unregister_device(priv->idev); 238 kfree(priv); 239 240 return 0; 241 } 242 243 static struct platform_driver mc13783_ts_driver = { 244 .remove = mc13783_ts_remove, 245 .driver = { 246 .name = MC13783_TS_NAME, 247 }, 248 }; 249 250 module_platform_driver_probe(mc13783_ts_driver, mc13783_ts_probe); 251 252 MODULE_DESCRIPTION("MC13783 input touchscreen driver"); 253 MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de>"); 254 MODULE_LICENSE("GPL v2"); 255 MODULE_ALIAS("platform:" MC13783_TS_NAME); 256