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 unsigned int sample[4]; 41 struct mc13xxx_ts_platform_data *touch; 42 }; 43 44 static irqreturn_t mc13783_ts_handler(int irq, void *data) 45 { 46 struct mc13783_ts_priv *priv = data; 47 48 mc13xxx_irq_ack(priv->mc13xxx, irq); 49 50 /* 51 * Kick off reading coordinates. Note that if work happens already 52 * be queued for future execution (it rearms itself) it will not 53 * be rescheduled for immediate execution here. However the rearm 54 * delay is HZ / 50 which is acceptable. 55 */ 56 schedule_delayed_work(&priv->work, 0); 57 58 return IRQ_HANDLED; 59 } 60 61 #define sort3(a0, a1, a2) ({ \ 62 if (a0 > a1) \ 63 swap(a0, a1); \ 64 if (a1 > a2) \ 65 swap(a1, a2); \ 66 if (a0 > a1) \ 67 swap(a0, a1); \ 68 }) 69 70 static void mc13783_ts_report_sample(struct mc13783_ts_priv *priv) 71 { 72 struct input_dev *idev = priv->idev; 73 int x0, x1, x2, y0, y1, y2; 74 int cr0, cr1; 75 76 /* 77 * the values are 10-bit wide only, but the two least significant 78 * bits are for future 12 bit use and reading yields 0 79 */ 80 x0 = priv->sample[0] & 0xfff; 81 x1 = priv->sample[1] & 0xfff; 82 x2 = priv->sample[2] & 0xfff; 83 y0 = priv->sample[3] & 0xfff; 84 y1 = (priv->sample[0] >> 12) & 0xfff; 85 y2 = (priv->sample[1] >> 12) & 0xfff; 86 cr0 = (priv->sample[2] >> 12) & 0xfff; 87 cr1 = (priv->sample[3] >> 12) & 0xfff; 88 89 dev_dbg(&idev->dev, 90 "x: (% 4d,% 4d,% 4d) y: (% 4d, % 4d,% 4d) cr: (% 4d, % 4d)\n", 91 x0, x1, x2, y0, y1, y2, cr0, cr1); 92 93 sort3(x0, x1, x2); 94 sort3(y0, y1, y2); 95 96 cr0 = (cr0 + cr1) / 2; 97 98 if (!cr0 || !sample_tolerance || 99 (x2 - x0 < sample_tolerance && 100 y2 - y0 < sample_tolerance)) { 101 /* report the median coordinate and average pressure */ 102 if (cr0) { 103 input_report_abs(idev, ABS_X, x1); 104 input_report_abs(idev, ABS_Y, y1); 105 106 dev_dbg(&idev->dev, "report (%d, %d, %d)\n", 107 x1, y1, 0x1000 - cr0); 108 schedule_delayed_work(&priv->work, HZ / 50); 109 } else { 110 dev_dbg(&idev->dev, "report release\n"); 111 } 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 } 121 122 static void mc13783_ts_work(struct work_struct *work) 123 { 124 struct mc13783_ts_priv *priv = 125 container_of(work, struct mc13783_ts_priv, work.work); 126 unsigned int mode = MC13XXX_ADC_MODE_TS; 127 unsigned int channel = 12; 128 129 if (mc13xxx_adc_do_conversion(priv->mc13xxx, 130 mode, channel, 131 priv->touch->ato, priv->touch->atox, 132 priv->sample) == 0) 133 mc13783_ts_report_sample(priv); 134 } 135 136 static int mc13783_ts_open(struct input_dev *dev) 137 { 138 struct mc13783_ts_priv *priv = input_get_drvdata(dev); 139 int ret; 140 141 mc13xxx_lock(priv->mc13xxx); 142 143 mc13xxx_irq_ack(priv->mc13xxx, MC13XXX_IRQ_TS); 144 145 ret = mc13xxx_irq_request(priv->mc13xxx, MC13XXX_IRQ_TS, 146 mc13783_ts_handler, MC13783_TS_NAME, priv); 147 if (ret) 148 goto out; 149 150 ret = mc13xxx_reg_rmw(priv->mc13xxx, MC13XXX_ADC0, 151 MC13XXX_ADC0_TSMOD_MASK, MC13XXX_ADC0_TSMOD0); 152 if (ret) 153 mc13xxx_irq_free(priv->mc13xxx, MC13XXX_IRQ_TS, priv); 154 out: 155 mc13xxx_unlock(priv->mc13xxx); 156 return ret; 157 } 158 159 static void mc13783_ts_close(struct input_dev *dev) 160 { 161 struct mc13783_ts_priv *priv = input_get_drvdata(dev); 162 163 mc13xxx_lock(priv->mc13xxx); 164 mc13xxx_reg_rmw(priv->mc13xxx, MC13XXX_ADC0, 165 MC13XXX_ADC0_TSMOD_MASK, 0); 166 mc13xxx_irq_free(priv->mc13xxx, MC13XXX_IRQ_TS, priv); 167 mc13xxx_unlock(priv->mc13xxx); 168 169 cancel_delayed_work_sync(&priv->work); 170 } 171 172 static int __init mc13783_ts_probe(struct platform_device *pdev) 173 { 174 struct mc13783_ts_priv *priv; 175 struct input_dev *idev; 176 int ret = -ENOMEM; 177 178 priv = kzalloc(sizeof(*priv), GFP_KERNEL); 179 idev = input_allocate_device(); 180 if (!priv || !idev) 181 goto err_free_mem; 182 183 INIT_DELAYED_WORK(&priv->work, mc13783_ts_work); 184 priv->mc13xxx = dev_get_drvdata(pdev->dev.parent); 185 priv->idev = idev; 186 priv->touch = dev_get_platdata(&pdev->dev); 187 if (!priv->touch) { 188 dev_err(&pdev->dev, "missing platform data\n"); 189 ret = -ENODEV; 190 goto err_free_mem; 191 } 192 193 idev->name = MC13783_TS_NAME; 194 idev->dev.parent = &pdev->dev; 195 196 idev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS); 197 idev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH); 198 input_set_abs_params(idev, ABS_X, 0, 0xfff, 0, 0); 199 input_set_abs_params(idev, ABS_Y, 0, 0xfff, 0, 0); 200 input_set_abs_params(idev, ABS_PRESSURE, 0, 0xfff, 0, 0); 201 202 idev->open = mc13783_ts_open; 203 idev->close = mc13783_ts_close; 204 205 input_set_drvdata(idev, priv); 206 207 ret = input_register_device(priv->idev); 208 if (ret) { 209 dev_err(&pdev->dev, 210 "register input device failed with %d\n", ret); 211 goto err_free_mem; 212 } 213 214 platform_set_drvdata(pdev, priv); 215 return 0; 216 217 err_free_mem: 218 input_free_device(idev); 219 kfree(priv); 220 return ret; 221 } 222 223 static int mc13783_ts_remove(struct platform_device *pdev) 224 { 225 struct mc13783_ts_priv *priv = platform_get_drvdata(pdev); 226 227 input_unregister_device(priv->idev); 228 kfree(priv); 229 230 return 0; 231 } 232 233 static struct platform_driver mc13783_ts_driver = { 234 .remove = mc13783_ts_remove, 235 .driver = { 236 .name = MC13783_TS_NAME, 237 }, 238 }; 239 240 module_platform_driver_probe(mc13783_ts_driver, mc13783_ts_probe); 241 242 MODULE_DESCRIPTION("MC13783 input touchscreen driver"); 243 MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de>"); 244 MODULE_LICENSE("GPL v2"); 245 MODULE_ALIAS("platform:" MC13783_TS_NAME); 246