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 mc13xxx_irq_ack(priv->mc13xxx, irq); 46 47 /* 48 * Kick off reading coordinates. Note that if work happens already 49 * be queued for future execution (it rearms itself) it will not 50 * be rescheduled for immediate execution here. However the rearm 51 * delay is HZ / 50 which is acceptable. 52 */ 53 schedule_delayed_work(&priv->work, 0); 54 55 return IRQ_HANDLED; 56 } 57 58 #define sort3(a0, a1, a2) ({ \ 59 if (a0 > a1) \ 60 swap(a0, a1); \ 61 if (a1 > a2) \ 62 swap(a1, a2); \ 63 if (a0 > a1) \ 64 swap(a0, a1); \ 65 }) 66 67 static void mc13783_ts_report_sample(struct mc13783_ts_priv *priv) 68 { 69 struct input_dev *idev = priv->idev; 70 int x0, x1, x2, y0, y1, y2; 71 int cr0, cr1; 72 73 /* 74 * the values are 10-bit wide only, but the two least significant 75 * bits are for future 12 bit use and reading yields 0 76 */ 77 x0 = priv->sample[0] & 0xfff; 78 x1 = priv->sample[1] & 0xfff; 79 x2 = priv->sample[2] & 0xfff; 80 y0 = priv->sample[3] & 0xfff; 81 y1 = (priv->sample[0] >> 12) & 0xfff; 82 y2 = (priv->sample[1] >> 12) & 0xfff; 83 cr0 = (priv->sample[2] >> 12) & 0xfff; 84 cr1 = (priv->sample[3] >> 12) & 0xfff; 85 86 dev_dbg(&idev->dev, 87 "x: (% 4d,% 4d,% 4d) y: (% 4d, % 4d,% 4d) cr: (% 4d, % 4d)\n", 88 x0, x1, x2, y0, y1, y2, cr0, cr1); 89 90 sort3(x0, x1, x2); 91 sort3(y0, y1, y2); 92 93 cr0 = (cr0 + cr1) / 2; 94 95 if (!cr0 || !sample_tolerance || 96 (x2 - x0 < sample_tolerance && 97 y2 - y0 < sample_tolerance)) { 98 /* report the median coordinate and average pressure */ 99 if (cr0) { 100 input_report_abs(idev, ABS_X, x1); 101 input_report_abs(idev, ABS_Y, y1); 102 103 dev_dbg(&idev->dev, "report (%d, %d, %d)\n", 104 x1, y1, 0x1000 - cr0); 105 schedule_delayed_work(&priv->work, HZ / 50); 106 } else { 107 dev_dbg(&idev->dev, "report release\n"); 108 } 109 110 input_report_abs(idev, ABS_PRESSURE, 111 cr0 ? 0x1000 - cr0 : cr0); 112 input_report_key(idev, BTN_TOUCH, cr0); 113 input_sync(idev); 114 } else { 115 dev_dbg(&idev->dev, "discard event\n"); 116 } 117 } 118 119 static void mc13783_ts_work(struct work_struct *work) 120 { 121 struct mc13783_ts_priv *priv = 122 container_of(work, struct mc13783_ts_priv, work.work); 123 unsigned int mode = MC13XXX_ADC_MODE_TS; 124 unsigned int channel = 12; 125 126 if (mc13xxx_adc_do_conversion(priv->mc13xxx, 127 mode, channel, 128 priv->touch->ato, priv->touch->atox, 129 priv->sample) == 0) 130 mc13783_ts_report_sample(priv); 131 } 132 133 static int mc13783_ts_open(struct input_dev *dev) 134 { 135 struct mc13783_ts_priv *priv = input_get_drvdata(dev); 136 int ret; 137 138 mc13xxx_lock(priv->mc13xxx); 139 140 mc13xxx_irq_ack(priv->mc13xxx, MC13XXX_IRQ_TS); 141 142 ret = mc13xxx_irq_request(priv->mc13xxx, MC13XXX_IRQ_TS, 143 mc13783_ts_handler, MC13783_TS_NAME, priv); 144 if (ret) 145 goto out; 146 147 ret = mc13xxx_reg_rmw(priv->mc13xxx, MC13XXX_ADC0, 148 MC13XXX_ADC0_TSMOD_MASK, MC13XXX_ADC0_TSMOD0); 149 if (ret) 150 mc13xxx_irq_free(priv->mc13xxx, MC13XXX_IRQ_TS, priv); 151 out: 152 mc13xxx_unlock(priv->mc13xxx); 153 return ret; 154 } 155 156 static void mc13783_ts_close(struct input_dev *dev) 157 { 158 struct mc13783_ts_priv *priv = input_get_drvdata(dev); 159 160 mc13xxx_lock(priv->mc13xxx); 161 mc13xxx_reg_rmw(priv->mc13xxx, MC13XXX_ADC0, 162 MC13XXX_ADC0_TSMOD_MASK, 0); 163 mc13xxx_irq_free(priv->mc13xxx, MC13XXX_IRQ_TS, priv); 164 mc13xxx_unlock(priv->mc13xxx); 165 166 cancel_delayed_work_sync(&priv->work); 167 } 168 169 static int __init mc13783_ts_probe(struct platform_device *pdev) 170 { 171 struct mc13783_ts_priv *priv; 172 struct input_dev *idev; 173 int ret = -ENOMEM; 174 175 priv = kzalloc(sizeof(*priv), GFP_KERNEL); 176 idev = input_allocate_device(); 177 if (!priv || !idev) 178 goto err_free_mem; 179 180 INIT_DELAYED_WORK(&priv->work, mc13783_ts_work); 181 priv->mc13xxx = dev_get_drvdata(pdev->dev.parent); 182 priv->idev = idev; 183 priv->touch = dev_get_platdata(&pdev->dev); 184 if (!priv->touch) { 185 dev_err(&pdev->dev, "missing platform data\n"); 186 ret = -ENODEV; 187 goto err_free_mem; 188 } 189 190 idev->name = MC13783_TS_NAME; 191 idev->dev.parent = &pdev->dev; 192 193 idev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS); 194 idev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH); 195 input_set_abs_params(idev, ABS_X, 0, 0xfff, 0, 0); 196 input_set_abs_params(idev, ABS_Y, 0, 0xfff, 0, 0); 197 input_set_abs_params(idev, ABS_PRESSURE, 0, 0xfff, 0, 0); 198 199 idev->open = mc13783_ts_open; 200 idev->close = mc13783_ts_close; 201 202 input_set_drvdata(idev, priv); 203 204 ret = input_register_device(priv->idev); 205 if (ret) { 206 dev_err(&pdev->dev, 207 "register input device failed with %d\n", ret); 208 goto err_free_mem; 209 } 210 211 platform_set_drvdata(pdev, priv); 212 return 0; 213 214 err_free_mem: 215 input_free_device(idev); 216 kfree(priv); 217 return ret; 218 } 219 220 static void mc13783_ts_remove(struct platform_device *pdev) 221 { 222 struct mc13783_ts_priv *priv = platform_get_drvdata(pdev); 223 224 input_unregister_device(priv->idev); 225 kfree(priv); 226 } 227 228 static struct platform_driver mc13783_ts_driver = { 229 .remove_new = mc13783_ts_remove, 230 .driver = { 231 .name = MC13783_TS_NAME, 232 }, 233 }; 234 235 module_platform_driver_probe(mc13783_ts_driver, mc13783_ts_probe); 236 237 MODULE_DESCRIPTION("MC13783 input touchscreen driver"); 238 MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de>"); 239 MODULE_LICENSE("GPL v2"); 240 MODULE_ALIAS("platform:" MC13783_TS_NAME); 241