xref: /openbmc/linux/drivers/input/misc/axp20x-pek.c (revision b96fc2f3)
1 /*
2  * axp20x power button driver.
3  *
4  * Copyright (C) 2013 Carlo Caione <carlo@caione.org>
5  *
6  * This file is subject to the terms and conditions of the GNU General
7  * Public License. See the file "COPYING" in the main directory of this
8  * archive for more details.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13  * GNU General Public License for more details.
14  */
15 
16 #include <linux/errno.h>
17 #include <linux/irq.h>
18 #include <linux/init.h>
19 #include <linux/input.h>
20 #include <linux/interrupt.h>
21 #include <linux/kernel.h>
22 #include <linux/mfd/axp20x.h>
23 #include <linux/module.h>
24 #include <linux/platform_device.h>
25 #include <linux/regmap.h>
26 #include <linux/slab.h>
27 
28 #define AXP20X_PEK_STARTUP_MASK		(0xc0)
29 #define AXP20X_PEK_SHUTDOWN_MASK	(0x03)
30 
31 struct axp20x_pek {
32 	struct axp20x_dev *axp20x;
33 	struct input_dev *input;
34 	int irq_dbr;
35 	int irq_dbf;
36 };
37 
38 struct axp20x_time {
39 	unsigned int time;
40 	unsigned int idx;
41 };
42 
43 static const struct axp20x_time startup_time[] = {
44 	{ .time = 128,  .idx = 0 },
45 	{ .time = 1000, .idx = 2 },
46 	{ .time = 3000, .idx = 1 },
47 	{ .time = 2000, .idx = 3 },
48 };
49 
50 static const struct axp20x_time shutdown_time[] = {
51 	{ .time = 4000,  .idx = 0 },
52 	{ .time = 6000,  .idx = 1 },
53 	{ .time = 8000,  .idx = 2 },
54 	{ .time = 10000, .idx = 3 },
55 };
56 
57 struct axp20x_pek_ext_attr {
58 	const struct axp20x_time *p_time;
59 	unsigned int mask;
60 };
61 
62 static struct axp20x_pek_ext_attr axp20x_pek_startup_ext_attr = {
63 	.p_time	= startup_time,
64 	.mask	= AXP20X_PEK_STARTUP_MASK,
65 };
66 
67 static struct axp20x_pek_ext_attr axp20x_pek_shutdown_ext_attr = {
68 	.p_time	= shutdown_time,
69 	.mask	= AXP20X_PEK_SHUTDOWN_MASK,
70 };
71 
72 static struct axp20x_pek_ext_attr *get_axp_ext_attr(struct device_attribute *attr)
73 {
74 	return container_of(attr, struct dev_ext_attribute, attr)->var;
75 }
76 
77 static ssize_t axp20x_show_ext_attr(struct device *dev,
78 				    struct device_attribute *attr, char *buf)
79 {
80 	struct axp20x_pek *axp20x_pek = dev_get_drvdata(dev);
81 	struct axp20x_pek_ext_attr *axp20x_ea = get_axp_ext_attr(attr);
82 	unsigned int val;
83 	int ret, i;
84 
85 	ret = regmap_read(axp20x_pek->axp20x->regmap, AXP20X_PEK_KEY, &val);
86 	if (ret != 0)
87 		return ret;
88 
89 	val &= axp20x_ea->mask;
90 	val >>= ffs(axp20x_ea->mask) - 1;
91 
92 	for (i = 0; i < 4; i++)
93 		if (val == axp20x_ea->p_time[i].idx)
94 			val = axp20x_ea->p_time[i].time;
95 
96 	return sprintf(buf, "%u\n", val);
97 }
98 
99 static ssize_t axp20x_store_ext_attr(struct device *dev,
100 				     struct device_attribute *attr,
101 				     const char *buf, size_t count)
102 {
103 	struct axp20x_pek *axp20x_pek = dev_get_drvdata(dev);
104 	struct axp20x_pek_ext_attr *axp20x_ea = get_axp_ext_attr(attr);
105 	char val_str[20];
106 	size_t len;
107 	int ret, i;
108 	unsigned int val, idx = 0;
109 	unsigned int best_err = UINT_MAX;
110 
111 	val_str[sizeof(val_str) - 1] = '\0';
112 	strncpy(val_str, buf, sizeof(val_str) - 1);
113 	len = strlen(val_str);
114 
115 	if (len && val_str[len - 1] == '\n')
116 		val_str[len - 1] = '\0';
117 
118 	ret = kstrtouint(val_str, 10, &val);
119 	if (ret)
120 		return ret;
121 
122 	for (i = 3; i >= 0; i--) {
123 		unsigned int err;
124 
125 		err = abs(axp20x_ea->p_time[i].time - val);
126 		if (err < best_err) {
127 			best_err = err;
128 			idx = axp20x_ea->p_time[i].idx;
129 		}
130 
131 		if (!err)
132 			break;
133 	}
134 
135 	idx <<= ffs(axp20x_ea->mask) - 1;
136 	ret = regmap_update_bits(axp20x_pek->axp20x->regmap,
137 				 AXP20X_PEK_KEY,
138 				 axp20x_ea->mask, idx);
139 	if (ret != 0)
140 		return -EINVAL;
141 
142 	return count;
143 }
144 
145 static struct dev_ext_attribute axp20x_dev_attr_startup = {
146 	.attr	= __ATTR(startup, 0644, axp20x_show_ext_attr, axp20x_store_ext_attr),
147 	.var	= &axp20x_pek_startup_ext_attr,
148 };
149 
150 static struct dev_ext_attribute axp20x_dev_attr_shutdown = {
151 	.attr	= __ATTR(shutdown, 0644, axp20x_show_ext_attr, axp20x_store_ext_attr),
152 	.var	= &axp20x_pek_shutdown_ext_attr,
153 };
154 
155 static struct attribute *axp20x_attributes[] = {
156 	&axp20x_dev_attr_startup.attr.attr,
157 	&axp20x_dev_attr_shutdown.attr.attr,
158 	NULL,
159 };
160 
161 static const struct attribute_group axp20x_attribute_group = {
162 	.attrs = axp20x_attributes,
163 };
164 
165 static irqreturn_t axp20x_pek_irq(int irq, void *pwr)
166 {
167 	struct input_dev *idev = pwr;
168 	struct axp20x_pek *axp20x_pek = input_get_drvdata(idev);
169 
170 	/*
171 	 * The power-button is connected to ground so a falling edge (dbf)
172 	 * means it is pressed.
173 	 */
174 	if (irq == axp20x_pek->irq_dbf)
175 		input_report_key(idev, KEY_POWER, true);
176 	else if (irq == axp20x_pek->irq_dbr)
177 		input_report_key(idev, KEY_POWER, false);
178 
179 	input_sync(idev);
180 
181 	return IRQ_HANDLED;
182 }
183 
184 static void axp20x_remove_sysfs_group(void *_data)
185 {
186 	struct device *dev = _data;
187 
188 	sysfs_remove_group(&dev->kobj, &axp20x_attribute_group);
189 }
190 
191 static int axp20x_pek_probe(struct platform_device *pdev)
192 {
193 	struct axp20x_pek *axp20x_pek;
194 	struct axp20x_dev *axp20x;
195 	struct input_dev *idev;
196 	int error;
197 
198 	axp20x_pek = devm_kzalloc(&pdev->dev, sizeof(struct axp20x_pek),
199 				  GFP_KERNEL);
200 	if (!axp20x_pek)
201 		return -ENOMEM;
202 
203 	axp20x_pek->axp20x = dev_get_drvdata(pdev->dev.parent);
204 	axp20x = axp20x_pek->axp20x;
205 
206 	axp20x_pek->irq_dbr = platform_get_irq_byname(pdev, "PEK_DBR");
207 	if (axp20x_pek->irq_dbr < 0) {
208 		dev_err(&pdev->dev, "No IRQ for PEK_DBR, error=%d\n",
209 				axp20x_pek->irq_dbr);
210 		return axp20x_pek->irq_dbr;
211 	}
212 	axp20x_pek->irq_dbr = regmap_irq_get_virq(axp20x->regmap_irqc,
213 						  axp20x_pek->irq_dbr);
214 
215 	axp20x_pek->irq_dbf = platform_get_irq_byname(pdev, "PEK_DBF");
216 	if (axp20x_pek->irq_dbf < 0) {
217 		dev_err(&pdev->dev, "No IRQ for PEK_DBF, error=%d\n",
218 				axp20x_pek->irq_dbf);
219 		return axp20x_pek->irq_dbf;
220 	}
221 	axp20x_pek->irq_dbf = regmap_irq_get_virq(axp20x->regmap_irqc,
222 						  axp20x_pek->irq_dbf);
223 
224 	axp20x_pek->input = devm_input_allocate_device(&pdev->dev);
225 	if (!axp20x_pek->input)
226 		return -ENOMEM;
227 
228 	idev = axp20x_pek->input;
229 
230 	idev->name = "axp20x-pek";
231 	idev->phys = "m1kbd/input2";
232 	idev->dev.parent = &pdev->dev;
233 
234 	input_set_capability(idev, EV_KEY, KEY_POWER);
235 
236 	input_set_drvdata(idev, axp20x_pek);
237 
238 	error = devm_request_any_context_irq(&pdev->dev, axp20x_pek->irq_dbr,
239 					     axp20x_pek_irq, 0,
240 					     "axp20x-pek-dbr", idev);
241 	if (error < 0) {
242 		dev_err(axp20x->dev, "Failed to request dbr IRQ#%d: %d\n",
243 			axp20x_pek->irq_dbr, error);
244 		return error;
245 	}
246 
247 	error = devm_request_any_context_irq(&pdev->dev, axp20x_pek->irq_dbf,
248 					  axp20x_pek_irq, 0,
249 					  "axp20x-pek-dbf", idev);
250 	if (error < 0) {
251 		dev_err(axp20x->dev, "Failed to request dbf IRQ#%d: %d\n",
252 			axp20x_pek->irq_dbf, error);
253 		return error;
254 	}
255 
256 	error = sysfs_create_group(&pdev->dev.kobj, &axp20x_attribute_group);
257 	if (error) {
258 		dev_err(axp20x->dev, "Failed to create sysfs attributes: %d\n",
259 			error);
260 		return error;
261 	}
262 
263 	error = devm_add_action(&pdev->dev,
264 				axp20x_remove_sysfs_group, &pdev->dev);
265 	if (error) {
266 		axp20x_remove_sysfs_group(&pdev->dev);
267 		dev_err(&pdev->dev, "Failed to add sysfs cleanup action: %d\n",
268 			error);
269 		return error;
270 	}
271 
272 	error = input_register_device(idev);
273 	if (error) {
274 		dev_err(axp20x->dev, "Can't register input device: %d\n",
275 			error);
276 		return error;
277 	}
278 
279 	platform_set_drvdata(pdev, axp20x_pek);
280 
281 	return 0;
282 }
283 
284 static struct platform_driver axp20x_pek_driver = {
285 	.probe		= axp20x_pek_probe,
286 	.driver		= {
287 		.name		= "axp20x-pek",
288 	},
289 };
290 module_platform_driver(axp20x_pek_driver);
291 
292 MODULE_DESCRIPTION("axp20x Power Button");
293 MODULE_AUTHOR("Carlo Caione <carlo@caione.org>");
294 MODULE_LICENSE("GPL");
295 MODULE_ALIAS("platform:axp20x-pek");
296