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
 31struct axp20x_pek {
 32	struct axp20x_dev *axp20x;
 33	struct input_dev *input;
 34	int irq_dbr;
 35	int irq_dbf;
 36};
 37
 38struct axp20x_time {
 39	unsigned int time;
 40	unsigned int idx;
 41};
 42
 43static 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
 50static 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
 57struct axp20x_pek_ext_attr {
 58	const struct axp20x_time *p_time;
 59	unsigned int mask;
 60};
 61
 62static struct axp20x_pek_ext_attr axp20x_pek_startup_ext_attr = {
 63	.p_time	= startup_time,
 64	.mask	= AXP20X_PEK_STARTUP_MASK,
 65};
 66
 67static struct axp20x_pek_ext_attr axp20x_pek_shutdown_ext_attr = {
 68	.p_time	= shutdown_time,
 69	.mask	= AXP20X_PEK_SHUTDOWN_MASK,
 70};
 71
 72static 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
 77static 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
 99static 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
145static 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
150static 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
155static struct attribute *axp20x_attributes[] = {
156	&axp20x_dev_attr_startup.attr.attr,
157	&axp20x_dev_attr_shutdown.attr.attr,
158	NULL,
159};
160
161static const struct attribute_group axp20x_attribute_group = {
162	.attrs = axp20x_attributes,
163};
164
165static 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
184static 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
191static 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
284static struct platform_driver axp20x_pek_driver = {
285	.probe		= axp20x_pek_probe,
286	.driver		= {
287		.name		= "axp20x-pek",
288	},
289};
290module_platform_driver(axp20x_pek_driver);
291
292MODULE_DESCRIPTION("axp20x Power Button");
293MODULE_AUTHOR("Carlo Caione <carlo@caione.org>");
294MODULE_LICENSE("GPL");
295MODULE_ALIAS("platform:axp20x-pek");