xref: /linux/drivers/input/misc/twl4030-pwrbutton.c (revision 913df4453f85f1fe79b35ecf3c9a0c0b707d22a2)
1 /**
2  * twl4030-pwrbutton.c - TWL4030 Power Button Input Driver
3  *
4  * Copyright (C) 2008-2009 Nokia Corporation
5  *
6  * Written by Peter De Schrijver <peter.de-schrijver@nokia.com>
7  * Several fixes by Felipe Balbi <felipe.balbi@nokia.com>
8  *
9  * This file is subject to the terms and conditions of the GNU General
10  * Public License. See the file "COPYING" in the main directory of this
11  * archive for more details.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  * GNU General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program; if not, write to the Free Software
20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
21  */
22 
23 #include <linux/module.h>
24 #include <linux/init.h>
25 #include <linux/kernel.h>
26 #include <linux/errno.h>
27 #include <linux/input.h>
28 #include <linux/interrupt.h>
29 #include <linux/platform_device.h>
30 #include <linux/i2c/twl4030.h>
31 
32 #define PWR_PWRON_IRQ (1 << 0)
33 
34 #define STS_HW_CONDITIONS 0xf
35 
36 static irqreturn_t powerbutton_irq(int irq, void *_pwr)
37 {
38 	struct input_dev *pwr = _pwr;
39 	int err;
40 	u8 value;
41 
42 #ifdef CONFIG_LOCKDEP
43 	/* WORKAROUND for lockdep forcing IRQF_DISABLED on us, which
44 	 * we don't want and can't tolerate since this is a threaded
45 	 * IRQ and can sleep due to the i2c reads it has to issue.
46 	 * Although it might be friendlier not to borrow this thread
47 	 * context...
48 	 */
49 	local_irq_enable();
50 #endif
51 
52 	err = twl4030_i2c_read_u8(TWL4030_MODULE_PM_MASTER, &value,
53 				  STS_HW_CONDITIONS);
54 	if (!err)  {
55 		input_report_key(pwr, KEY_POWER, value & PWR_PWRON_IRQ);
56 		input_sync(pwr);
57 	} else {
58 		dev_err(pwr->dev.parent, "twl4030: i2c error %d while reading"
59 			" TWL4030 PM_MASTER STS_HW_CONDITIONS register\n", err);
60 	}
61 
62 	return IRQ_HANDLED;
63 }
64 
65 static int __devinit twl4030_pwrbutton_probe(struct platform_device *pdev)
66 {
67 	struct input_dev *pwr;
68 	int irq = platform_get_irq(pdev, 0);
69 	int err;
70 
71 	pwr = input_allocate_device();
72 	if (!pwr) {
73 		dev_dbg(&pdev->dev, "Can't allocate power button\n");
74 		return -ENOMEM;
75 	}
76 
77 	pwr->evbit[0] = BIT_MASK(EV_KEY);
78 	pwr->keybit[BIT_WORD(KEY_POWER)] = BIT_MASK(KEY_POWER);
79 	pwr->name = "twl4030_pwrbutton";
80 	pwr->phys = "twl4030_pwrbutton/input0";
81 	pwr->dev.parent = &pdev->dev;
82 
83 	err = request_irq(irq, powerbutton_irq,
84 			IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,
85 			"twl4030_pwrbutton", pwr);
86 	if (err < 0) {
87 		dev_dbg(&pdev->dev, "Can't get IRQ for pwrbutton: %d\n", err);
88 		goto free_input_dev;
89 	}
90 
91 	err = input_register_device(pwr);
92 	if (err) {
93 		dev_dbg(&pdev->dev, "Can't register power button: %d\n", err);
94 		goto free_irq;
95 	}
96 
97 	platform_set_drvdata(pdev, pwr);
98 
99 	return 0;
100 
101 free_irq:
102 	free_irq(irq, NULL);
103 free_input_dev:
104 	input_free_device(pwr);
105 	return err;
106 }
107 
108 static int __devexit twl4030_pwrbutton_remove(struct platform_device *pdev)
109 {
110 	struct input_dev *pwr = platform_get_drvdata(pdev);
111 	int irq = platform_get_irq(pdev, 0);
112 
113 	free_irq(irq, pwr);
114 	input_unregister_device(pwr);
115 
116 	return 0;
117 }
118 
119 struct platform_driver twl4030_pwrbutton_driver = {
120 	.probe		= twl4030_pwrbutton_probe,
121 	.remove		= __devexit_p(twl4030_pwrbutton_remove),
122 	.driver		= {
123 		.name	= "twl4030_pwrbutton",
124 		.owner	= THIS_MODULE,
125 	},
126 };
127 
128 static int __init twl4030_pwrbutton_init(void)
129 {
130 	return platform_driver_register(&twl4030_pwrbutton_driver);
131 }
132 module_init(twl4030_pwrbutton_init);
133 
134 static void __exit twl4030_pwrbutton_exit(void)
135 {
136 	platform_driver_unregister(&twl4030_pwrbutton_driver);
137 }
138 module_exit(twl4030_pwrbutton_exit);
139 
140 MODULE_ALIAS("platform:twl4030_pwrbutton");
141 MODULE_DESCRIPTION("Triton2 Power Button");
142 MODULE_LICENSE("GPL");
143 MODULE_AUTHOR("Peter De Schrijver <peter.de-schrijver@nokia.com>");
144 MODULE_AUTHOR("Felipe Balbi <felipe.balbi@nokia.com>");
145 
146