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d201fd5d SH |
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> | |
5a0e3ad6 | 20 | #include <linux/slab.h> |
d201fd5d SH |
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 mc13783 *mc13783; | |
39 | struct delayed_work work; | |
40 | struct workqueue_struct *workq; | |
41 | unsigned int sample[4]; | |
42 | }; | |
43 | ||
44 | static irqreturn_t mc13783_ts_handler(int irq, void *data) | |
45 | { | |
46 | struct mc13783_ts_priv *priv = data; | |
47 | ||
2a833191 | 48 | mc13783_irq_ack(priv->mc13783, irq); |
d201fd5d SH |
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 | queue_delayed_work(priv->workq, &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 | queue_delayed_work(priv->workq, &priv->work, HZ / 50); | |
109 | } else | |
110 | dev_dbg(&idev->dev, "report release\n"); | |
111 | ||
112 | input_report_abs(idev, ABS_PRESSURE, | |
113 | cr0 ? 0x1000 - cr0 : cr0); | |
114 | input_report_key(idev, BTN_TOUCH, cr0); | |
115 | input_sync(idev); | |
116 | } else | |
117 | dev_dbg(&idev->dev, "discard event\n"); | |
118 | } | |
119 | ||
120 | static void mc13783_ts_work(struct work_struct *work) | |
121 | { | |
122 | struct mc13783_ts_priv *priv = | |
123 | container_of(work, struct mc13783_ts_priv, work.work); | |
124 | unsigned int mode = MC13783_ADC_MODE_TS; | |
125 | unsigned int channel = 12; | |
126 | ||
127 | if (mc13783_adc_do_conversion(priv->mc13783, | |
128 | mode, channel, priv->sample) == 0) | |
129 | mc13783_ts_report_sample(priv); | |
130 | } | |
131 | ||
132 | static int mc13783_ts_open(struct input_dev *dev) | |
133 | { | |
134 | struct mc13783_ts_priv *priv = input_get_drvdata(dev); | |
135 | int ret; | |
136 | ||
137 | mc13783_lock(priv->mc13783); | |
138 | ||
2a833191 | 139 | mc13783_irq_ack(priv->mc13783, MC13783_IRQ_TS); |
d201fd5d SH |
140 | |
141 | ret = mc13783_irq_request(priv->mc13783, MC13783_IRQ_TS, | |
142 | mc13783_ts_handler, MC13783_TS_NAME, priv); | |
143 | if (ret) | |
144 | goto out; | |
145 | ||
146 | ret = mc13783_reg_rmw(priv->mc13783, MC13783_ADC0, | |
147 | MC13783_ADC0_TSMOD_MASK, MC13783_ADC0_TSMOD0); | |
148 | if (ret) | |
149 | mc13783_irq_free(priv->mc13783, MC13783_IRQ_TS, priv); | |
150 | out: | |
151 | mc13783_unlock(priv->mc13783); | |
152 | return ret; | |
153 | } | |
154 | ||
155 | static void mc13783_ts_close(struct input_dev *dev) | |
156 | { | |
157 | struct mc13783_ts_priv *priv = input_get_drvdata(dev); | |
158 | ||
159 | mc13783_lock(priv->mc13783); | |
160 | mc13783_reg_rmw(priv->mc13783, MC13783_ADC0, | |
161 | MC13783_ADC0_TSMOD_MASK, 0); | |
162 | mc13783_irq_free(priv->mc13783, MC13783_IRQ_TS, priv); | |
163 | mc13783_unlock(priv->mc13783); | |
164 | ||
165 | cancel_delayed_work_sync(&priv->work); | |
166 | } | |
167 | ||
168 | static int __init mc13783_ts_probe(struct platform_device *pdev) | |
169 | { | |
170 | struct mc13783_ts_priv *priv; | |
171 | struct input_dev *idev; | |
172 | int ret = -ENOMEM; | |
173 | ||
174 | priv = kzalloc(sizeof(*priv), GFP_KERNEL); | |
175 | idev = input_allocate_device(); | |
176 | if (!priv || !idev) | |
177 | goto err_free_mem; | |
178 | ||
179 | INIT_DELAYED_WORK(&priv->work, mc13783_ts_work); | |
180 | priv->mc13783 = dev_get_drvdata(pdev->dev.parent); | |
181 | priv->idev = idev; | |
182 | ||
183 | /* | |
184 | * We need separate workqueue because mc13783_adc_do_conversion | |
185 | * uses keventd and thus would deadlock. | |
186 | */ | |
187 | priv->workq = create_singlethread_workqueue("mc13783_ts"); | |
188 | if (!priv->workq) | |
189 | goto err_free_mem; | |
190 | ||
191 | idev->name = MC13783_TS_NAME; | |
192 | idev->dev.parent = &pdev->dev; | |
193 | ||
194 | idev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS); | |
195 | idev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH); | |
196 | input_set_abs_params(idev, ABS_X, 0, 0xfff, 0, 0); | |
197 | input_set_abs_params(idev, ABS_Y, 0, 0xfff, 0, 0); | |
198 | input_set_abs_params(idev, ABS_PRESSURE, 0, 0xfff, 0, 0); | |
199 | ||
200 | idev->open = mc13783_ts_open; | |
201 | idev->close = mc13783_ts_close; | |
202 | ||
203 | input_set_drvdata(idev, priv); | |
204 | ||
205 | ret = input_register_device(priv->idev); | |
206 | if (ret) { | |
207 | dev_err(&pdev->dev, | |
208 | "register input device failed with %d\n", ret); | |
209 | goto err_destroy_wq; | |
210 | } | |
211 | ||
212 | platform_set_drvdata(pdev, priv); | |
213 | return 0; | |
214 | ||
215 | err_destroy_wq: | |
216 | destroy_workqueue(priv->workq); | |
217 | err_free_mem: | |
218 | input_free_device(idev); | |
219 | kfree(priv); | |
220 | return ret; | |
221 | } | |
222 | ||
223 | static int __devexit mc13783_ts_remove(struct platform_device *pdev) | |
224 | { | |
225 | struct mc13783_ts_priv *priv = platform_get_drvdata(pdev); | |
226 | ||
227 | platform_set_drvdata(pdev, NULL); | |
228 | ||
229 | destroy_workqueue(priv->workq); | |
230 | input_unregister_device(priv->idev); | |
231 | kfree(priv); | |
232 | ||
233 | return 0; | |
234 | } | |
235 | ||
236 | static struct platform_driver mc13783_ts_driver = { | |
237 | .remove = __devexit_p(mc13783_ts_remove), | |
238 | .driver = { | |
239 | .owner = THIS_MODULE, | |
240 | .name = MC13783_TS_NAME, | |
241 | }, | |
242 | }; | |
243 | ||
244 | static int __init mc13783_ts_init(void) | |
245 | { | |
246 | return platform_driver_probe(&mc13783_ts_driver, &mc13783_ts_probe); | |
247 | } | |
248 | module_init(mc13783_ts_init); | |
249 | ||
250 | static void __exit mc13783_ts_exit(void) | |
251 | { | |
252 | platform_driver_unregister(&mc13783_ts_driver); | |
253 | } | |
254 | module_exit(mc13783_ts_exit); | |
255 | ||
256 | MODULE_DESCRIPTION("MC13783 input touchscreen driver"); | |
257 | MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de>"); | |
258 | MODULE_LICENSE("GPL v2"); | |
259 | MODULE_ALIAS("platform:" MC13783_TS_NAME); |