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(mc13xxx: 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(dwork: &priv->work, delay: 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(dev: idev, ABS_X, value: x1); |
101 | input_report_abs(dev: idev, ABS_Y, value: y1); |
102 | |
103 | dev_dbg(&idev->dev, "report (%d, %d, %d)\n" , |
104 | x1, y1, 0x1000 - cr0); |
105 | schedule_delayed_work(dwork: &priv->work, HZ / 50); |
106 | } else { |
107 | dev_dbg(&idev->dev, "report release\n" ); |
108 | } |
109 | |
110 | input_report_abs(dev: idev, ABS_PRESSURE, |
111 | value: cr0 ? 0x1000 - cr0 : cr0); |
112 | input_report_key(dev: idev, BTN_TOUCH, value: cr0); |
113 | input_sync(dev: 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(mc13xxx: priv->mc13xxx, |
127 | mode, channel, |
128 | ato: priv->touch->ato, atox: priv->touch->atox, |
129 | sample: 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(mc13xxx: priv->mc13xxx); |
139 | |
140 | mc13xxx_irq_ack(mc13xxx: priv->mc13xxx, MC13XXX_IRQ_TS); |
141 | |
142 | ret = mc13xxx_irq_request(mc13xxx: priv->mc13xxx, MC13XXX_IRQ_TS, |
143 | handler: mc13783_ts_handler, MC13783_TS_NAME, dev: priv); |
144 | if (ret) |
145 | goto out; |
146 | |
147 | ret = mc13xxx_reg_rmw(mc13xxx: priv->mc13xxx, MC13XXX_ADC0, |
148 | MC13XXX_ADC0_TSMOD_MASK, MC13XXX_ADC0_TSMOD0); |
149 | if (ret) |
150 | mc13xxx_irq_free(mc13xxx: priv->mc13xxx, MC13XXX_IRQ_TS, dev: priv); |
151 | out: |
152 | mc13xxx_unlock(mc13xxx: 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(mc13xxx: priv->mc13xxx); |
161 | mc13xxx_reg_rmw(mc13xxx: priv->mc13xxx, MC13XXX_ADC0, |
162 | MC13XXX_ADC0_TSMOD_MASK, val: 0); |
163 | mc13xxx_irq_free(mc13xxx: priv->mc13xxx, MC13XXX_IRQ_TS, dev: priv); |
164 | mc13xxx_unlock(mc13xxx: priv->mc13xxx); |
165 | |
166 | cancel_delayed_work_sync(dwork: &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(size: 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(dev: pdev->dev.parent); |
182 | priv->idev = idev; |
183 | priv->touch = dev_get_platdata(dev: &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(dev: idev, ABS_X, min: 0, max: 0xfff, fuzz: 0, flat: 0); |
196 | input_set_abs_params(dev: idev, ABS_Y, min: 0, max: 0xfff, fuzz: 0, flat: 0); |
197 | input_set_abs_params(dev: idev, ABS_PRESSURE, min: 0, max: 0xfff, fuzz: 0, flat: 0); |
198 | |
199 | idev->open = mc13783_ts_open; |
200 | idev->close = mc13783_ts_close; |
201 | |
202 | input_set_drvdata(dev: idev, data: 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, data: priv); |
212 | return 0; |
213 | |
214 | err_free_mem: |
215 | input_free_device(dev: idev); |
216 | kfree(objp: priv); |
217 | return ret; |
218 | } |
219 | |
220 | static int 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(objp: priv); |
226 | |
227 | return 0; |
228 | } |
229 | |
230 | static struct platform_driver mc13783_ts_driver = { |
231 | .remove = mc13783_ts_remove, |
232 | .driver = { |
233 | .name = MC13783_TS_NAME, |
234 | }, |
235 | }; |
236 | |
237 | module_platform_driver_probe(mc13783_ts_driver, mc13783_ts_probe); |
238 | |
239 | MODULE_DESCRIPTION("MC13783 input touchscreen driver" ); |
240 | MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de>" ); |
241 | MODULE_LICENSE("GPL v2" ); |
242 | MODULE_ALIAS("platform:" MC13783_TS_NAME); |
243 | |