1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Driver for the Freescale Semiconductor MC13783 touchscreen. 4 * 5 * Copyright 2004-2007 Freescale Semiconductor, Inc. All Rights Reserved. 6 * Copyright (C) 2009 Sascha Hauer, Pengutronix 7 * 8 * Initial development of this code was funded by 9 * Phytec Messtechnik GmbH, http://www.phytec.de/ 10 */ 11 #include <linux/platform_device.h> 12 #include <linux/mfd/mc13783.h> 13 #include <linux/kernel.h> 14 #include <linux/module.h> 15 #include <linux/input.h> 16 #include <linux/sched.h> 17 #include <linux/slab.h> 18 #include <linux/init.h> 19 20 #define MC13783_TS_NAME "mc13783-ts" 21 22 #define DEFAULT_SAMPLE_TOLERANCE 300 23 24 static unsigned int sample_tolerance = DEFAULT_SAMPLE_TOLERANCE; 25 module_param(sample_tolerance, uint, S_IRUGO | S_IWUSR); 26 MODULE_PARM_DESC(sample_tolerance, 27 "If the minimal and maximal value read out for one axis (out " 28 "of three) differ by this value (default: " 29 __stringify(DEFAULT_SAMPLE_TOLERANCE) ") or more, the reading " 30 "is supposed to be wrong and is discarded. Set to 0 to " 31 "disable this check."); 32 33 struct mc13783_ts_priv { 34 struct input_dev *idev; 35 struct mc13xxx *mc13xxx; 36 struct delayed_work work; 37 unsigned int sample[4]; 38 struct mc13xxx_ts_platform_data *touch; 39 }; 40 41 static irqreturn_t mc13783_ts_handler(int irq, void *data) 42 { 43 struct mc13783_ts_priv *priv = data; 44 45 /* 46 * Kick off reading coordinates. Note that if work happens already 47 * be queued for future execution (it rearms itself) it will not 48 * be rescheduled for immediate execution here. However the rearm 49 * delay is HZ / 50 which is acceptable. 50 */ 51 schedule_delayed_work(&priv->work, 0); 52 53 return IRQ_HANDLED; 54 } 55 56 #define sort3(a0, a1, a2) ({ \ 57 if (a0 > a1) \ 58 swap(a0, a1); \ 59 if (a1 > a2) \ 60 swap(a1, a2); \ 61 if (a0 > a1) \ 62 swap(a0, a1); \ 63 }) 64 65 static void mc13783_ts_report_sample(struct mc13783_ts_priv *priv) 66 { 67 struct input_dev *idev = priv->idev; 68 int x0, x1, x2, y0, y1, y2; 69 int cr0, cr1; 70 71 /* 72 * the values are 10-bit wide only, but the two least significant 73 * bits are for future 12 bit use and reading yields 0 74 */ 75 x0 = priv->sample[0] & 0xfff; 76 x1 = priv->sample[1] & 0xfff; 77 x2 = priv->sample[2] & 0xfff; 78 y0 = priv->sample[3] & 0xfff; 79 y1 = (priv->sample[0] >> 12) & 0xfff; 80 y2 = (priv->sample[1] >> 12) & 0xfff; 81 cr0 = (priv->sample[2] >> 12) & 0xfff; 82 cr1 = (priv->sample[3] >> 12) & 0xfff; 83 84 dev_dbg(&idev->dev, 85 "x: (% 4d,% 4d,% 4d) y: (% 4d, % 4d,% 4d) cr: (% 4d, % 4d)\n", 86 x0, x1, x2, y0, y1, y2, cr0, cr1); 87 88 sort3(x0, x1, x2); 89 sort3(y0, y1, y2); 90 91 cr0 = (cr0 + cr1) / 2; 92 93 if (!cr0 || !sample_tolerance || 94 (x2 - x0 < sample_tolerance && 95 y2 - y0 < sample_tolerance)) { 96 /* report the median coordinate and average pressure */ 97 if (cr0) { 98 input_report_abs(idev, ABS_X, x1); 99 input_report_abs(idev, ABS_Y, y1); 100 101 dev_dbg(&idev->dev, "report (%d, %d, %d)\n", 102 x1, y1, 0x1000 - cr0); 103 schedule_delayed_work(&priv->work, HZ / 50); 104 } else { 105 dev_dbg(&idev->dev, "report release\n"); 106 } 107 108 input_report_abs(idev, ABS_PRESSURE, 109 cr0 ? 0x1000 - cr0 : cr0); 110 input_report_key(idev, BTN_TOUCH, cr0); 111 input_sync(idev); 112 } else { 113 dev_dbg(&idev->dev, "discard event\n"); 114 } 115 } 116 117 static void mc13783_ts_work(struct work_struct *work) 118 { 119 struct mc13783_ts_priv *priv = 120 container_of(work, struct mc13783_ts_priv, work.work); 121 unsigned int mode = MC13XXX_ADC_MODE_TS; 122 unsigned int channel = 12; 123 124 if (mc13xxx_adc_do_conversion(priv->mc13xxx, 125 mode, channel, 126 priv->touch->ato, priv->touch->atox, 127 priv->sample) == 0) 128 mc13783_ts_report_sample(priv); 129 } 130 131 static int mc13783_ts_open(struct input_dev *dev) 132 { 133 struct mc13783_ts_priv *priv = input_get_drvdata(dev); 134 int ret; 135 136 mc13xxx_lock(priv->mc13xxx); 137 138 ret = mc13xxx_irq_request(priv->mc13xxx, MC13XXX_IRQ_TS, 139 mc13783_ts_handler, MC13783_TS_NAME, priv); 140 if (ret) 141 goto out; 142 143 ret = mc13xxx_reg_rmw(priv->mc13xxx, MC13XXX_ADC0, 144 MC13XXX_ADC0_TSMOD_MASK, MC13XXX_ADC0_TSMOD0); 145 if (ret) 146 mc13xxx_irq_free(priv->mc13xxx, MC13XXX_IRQ_TS, priv); 147 out: 148 mc13xxx_unlock(priv->mc13xxx); 149 return ret; 150 } 151 152 static void mc13783_ts_close(struct input_dev *dev) 153 { 154 struct mc13783_ts_priv *priv = input_get_drvdata(dev); 155 156 mc13xxx_lock(priv->mc13xxx); 157 mc13xxx_reg_rmw(priv->mc13xxx, MC13XXX_ADC0, 158 MC13XXX_ADC0_TSMOD_MASK, 0); 159 mc13xxx_irq_free(priv->mc13xxx, MC13XXX_IRQ_TS, priv); 160 mc13xxx_unlock(priv->mc13xxx); 161 162 cancel_delayed_work_sync(&priv->work); 163 } 164 165 static int __init mc13783_ts_probe(struct platform_device *pdev) 166 { 167 struct mc13783_ts_priv *priv; 168 struct input_dev *idev; 169 int ret = -ENOMEM; 170 171 priv = kzalloc(sizeof(*priv), GFP_KERNEL); 172 idev = input_allocate_device(); 173 if (!priv || !idev) 174 goto err_free_mem; 175 176 INIT_DELAYED_WORK(&priv->work, mc13783_ts_work); 177 priv->mc13xxx = dev_get_drvdata(pdev->dev.parent); 178 priv->idev = idev; 179 priv->touch = dev_get_platdata(&pdev->dev); 180 if (!priv->touch) { 181 dev_err(&pdev->dev, "missing platform data\n"); 182 ret = -ENODEV; 183 goto err_free_mem; 184 } 185 186 idev->name = MC13783_TS_NAME; 187 idev->dev.parent = &pdev->dev; 188 189 idev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS); 190 idev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH); 191 input_set_abs_params(idev, ABS_X, 0, 0xfff, 0, 0); 192 input_set_abs_params(idev, ABS_Y, 0, 0xfff, 0, 0); 193 input_set_abs_params(idev, ABS_PRESSURE, 0, 0xfff, 0, 0); 194 195 idev->open = mc13783_ts_open; 196 idev->close = mc13783_ts_close; 197 198 input_set_drvdata(idev, priv); 199 200 ret = input_register_device(priv->idev); 201 if (ret) { 202 dev_err(&pdev->dev, 203 "register input device failed with %d\n", ret); 204 goto err_free_mem; 205 } 206 207 platform_set_drvdata(pdev, priv); 208 return 0; 209 210 err_free_mem: 211 input_free_device(idev); 212 kfree(priv); 213 return ret; 214 } 215 216 static void mc13783_ts_remove(struct platform_device *pdev) 217 { 218 struct mc13783_ts_priv *priv = platform_get_drvdata(pdev); 219 220 input_unregister_device(priv->idev); 221 kfree(priv); 222 } 223 224 static struct platform_driver mc13783_ts_driver = { 225 .remove = mc13783_ts_remove, 226 .driver = { 227 .name = MC13783_TS_NAME, 228 }, 229 }; 230 231 module_platform_driver_probe(mc13783_ts_driver, mc13783_ts_probe); 232 233 MODULE_DESCRIPTION("MC13783 input touchscreen driver"); 234 MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de>"); 235 MODULE_LICENSE("GPL v2"); 236 MODULE_ALIAS("platform:" MC13783_TS_NAME); 237