1 /*
2  * Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved.
3  * Copyright (c) 2014, Sony Mobile Communications Inc.
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License version 2 and
7  * only version 2 as published by the Free Software Foundation.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  */
14 
15 #include <linux/delay.h>
16 #include <linux/errno.h>
17 #include <linux/input.h>
18 #include <linux/interrupt.h>
19 #include <linux/kernel.h>
20 #include <linux/log2.h>
21 #include <linux/module.h>
22 #include <linux/of.h>
23 #include <linux/of_device.h>
24 #include <linux/platform_device.h>
25 #include <linux/reboot.h>
26 #include <linux/regmap.h>
27 
28 #define PON_REV2			0x01
29 
30 #define PON_RT_STS			0x10
31 #define  PON_KPDPWR_N_SET		BIT(0)
32 #define  PON_RESIN_N_SET		BIT(1)
33 
34 #define PON_PS_HOLD_RST_CTL		0x5a
35 #define PON_PS_HOLD_RST_CTL2		0x5b
36 #define  PON_PS_HOLD_ENABLE		BIT(7)
37 #define  PON_PS_HOLD_TYPE_MASK		0x0f
38 #define  PON_PS_HOLD_TYPE_SHUTDOWN	4
39 #define  PON_PS_HOLD_TYPE_HARD_RESET	7
40 
41 #define PON_PULL_CTL			0x70
42 #define  PON_KPDPWR_PULL_UP		BIT(1)
43 #define  PON_RESIN_PULL_UP		BIT(0)
44 
45 #define PON_DBC_CTL			0x71
46 #define  PON_DBC_DELAY_MASK		0x7
47 
48 struct pm8941_data {
49 	unsigned int pull_up_bit;
50 	unsigned int status_bit;
51 };
52 
53 struct pm8941_pwrkey {
54 	struct device *dev;
55 	int irq;
56 	u32 baseaddr;
57 	struct regmap *regmap;
58 	struct input_dev *input;
59 
60 	unsigned int revision;
61 	struct notifier_block reboot_notifier;
62 
63 	u32 code;
64 	const struct pm8941_data *data;
65 };
66 
67 static int pm8941_reboot_notify(struct notifier_block *nb,
68 				unsigned long code, void *unused)
69 {
70 	struct pm8941_pwrkey *pwrkey = container_of(nb, struct pm8941_pwrkey,
71 						    reboot_notifier);
72 	unsigned int enable_reg;
73 	unsigned int reset_type;
74 	int error;
75 
76 	/* PMICs with revision 0 have the enable bit in same register as ctrl */
77 	if (pwrkey->revision == 0)
78 		enable_reg = PON_PS_HOLD_RST_CTL;
79 	else
80 		enable_reg = PON_PS_HOLD_RST_CTL2;
81 
82 	error = regmap_update_bits(pwrkey->regmap,
83 				   pwrkey->baseaddr + enable_reg,
84 				   PON_PS_HOLD_ENABLE,
85 				   0);
86 	if (error)
87 		dev_err(pwrkey->dev,
88 			"unable to clear ps hold reset enable: %d\n",
89 			error);
90 
91 	/*
92 	 * Updates of PON_PS_HOLD_ENABLE requires 3 sleep cycles between
93 	 * writes.
94 	 */
95 	usleep_range(100, 1000);
96 
97 	switch (code) {
98 	case SYS_HALT:
99 	case SYS_POWER_OFF:
100 		reset_type = PON_PS_HOLD_TYPE_SHUTDOWN;
101 		break;
102 	case SYS_RESTART:
103 	default:
104 		reset_type = PON_PS_HOLD_TYPE_HARD_RESET;
105 		break;
106 	}
107 
108 	error = regmap_update_bits(pwrkey->regmap,
109 				   pwrkey->baseaddr + PON_PS_HOLD_RST_CTL,
110 				   PON_PS_HOLD_TYPE_MASK,
111 				   reset_type);
112 	if (error)
113 		dev_err(pwrkey->dev, "unable to set ps hold reset type: %d\n",
114 			error);
115 
116 	error = regmap_update_bits(pwrkey->regmap,
117 				   pwrkey->baseaddr + enable_reg,
118 				   PON_PS_HOLD_ENABLE,
119 				   PON_PS_HOLD_ENABLE);
120 	if (error)
121 		dev_err(pwrkey->dev, "unable to re-set enable: %d\n", error);
122 
123 	return NOTIFY_DONE;
124 }
125 
126 static irqreturn_t pm8941_pwrkey_irq(int irq, void *_data)
127 {
128 	struct pm8941_pwrkey *pwrkey = _data;
129 	unsigned int sts;
130 	int error;
131 
132 	error = regmap_read(pwrkey->regmap,
133 			    pwrkey->baseaddr + PON_RT_STS, &sts);
134 	if (error)
135 		return IRQ_HANDLED;
136 
137 	input_report_key(pwrkey->input, pwrkey->code,
138 			 sts & pwrkey->data->status_bit);
139 	input_sync(pwrkey->input);
140 
141 	return IRQ_HANDLED;
142 }
143 
144 static int __maybe_unused pm8941_pwrkey_suspend(struct device *dev)
145 {
146 	struct pm8941_pwrkey *pwrkey = dev_get_drvdata(dev);
147 
148 	if (device_may_wakeup(dev))
149 		enable_irq_wake(pwrkey->irq);
150 
151 	return 0;
152 }
153 
154 static int __maybe_unused pm8941_pwrkey_resume(struct device *dev)
155 {
156 	struct pm8941_pwrkey *pwrkey = dev_get_drvdata(dev);
157 
158 	if (device_may_wakeup(dev))
159 		disable_irq_wake(pwrkey->irq);
160 
161 	return 0;
162 }
163 
164 static SIMPLE_DEV_PM_OPS(pm8941_pwr_key_pm_ops,
165 			 pm8941_pwrkey_suspend, pm8941_pwrkey_resume);
166 
167 static int pm8941_pwrkey_probe(struct platform_device *pdev)
168 {
169 	struct pm8941_pwrkey *pwrkey;
170 	bool pull_up;
171 	struct device *parent;
172 	u32 req_delay;
173 	int error;
174 
175 	if (of_property_read_u32(pdev->dev.of_node, "debounce", &req_delay))
176 		req_delay = 15625;
177 
178 	if (req_delay > 2000000 || req_delay == 0) {
179 		dev_err(&pdev->dev, "invalid debounce time: %u\n", req_delay);
180 		return -EINVAL;
181 	}
182 
183 	pull_up = of_property_read_bool(pdev->dev.of_node, "bias-pull-up");
184 
185 	pwrkey = devm_kzalloc(&pdev->dev, sizeof(*pwrkey), GFP_KERNEL);
186 	if (!pwrkey)
187 		return -ENOMEM;
188 
189 	pwrkey->dev = &pdev->dev;
190 	pwrkey->data = of_device_get_match_data(&pdev->dev);
191 
192 	parent = pdev->dev.parent;
193 	pwrkey->regmap = dev_get_regmap(parent, NULL);
194 	if (!pwrkey->regmap) {
195 		/*
196 		 * We failed to get regmap for parent. Let's see if we are
197 		 * a child of pon node and read regmap and reg from its
198 		 * parent.
199 		 */
200 		pwrkey->regmap = dev_get_regmap(parent->parent, NULL);
201 		if (!pwrkey->regmap) {
202 			dev_err(&pdev->dev, "failed to locate regmap\n");
203 			return -ENODEV;
204 		}
205 
206 		error = of_property_read_u32(parent->of_node,
207 					     "reg", &pwrkey->baseaddr);
208 	} else {
209 		error = of_property_read_u32(pdev->dev.of_node, "reg",
210 					     &pwrkey->baseaddr);
211 	}
212 	if (error)
213 		return error;
214 
215 	pwrkey->irq = platform_get_irq(pdev, 0);
216 	if (pwrkey->irq < 0) {
217 		dev_err(&pdev->dev, "failed to get irq\n");
218 		return pwrkey->irq;
219 	}
220 
221 	error = regmap_read(pwrkey->regmap, pwrkey->baseaddr + PON_REV2,
222 			    &pwrkey->revision);
223 	if (error) {
224 		dev_err(&pdev->dev, "failed to set debounce: %d\n", error);
225 		return error;
226 	}
227 
228 	error = of_property_read_u32(pdev->dev.of_node, "linux,code",
229 				     &pwrkey->code);
230 	if (error) {
231 		dev_dbg(&pdev->dev,
232 			"no linux,code assuming power (%d)\n", error);
233 		pwrkey->code = KEY_POWER;
234 	}
235 
236 	pwrkey->input = devm_input_allocate_device(&pdev->dev);
237 	if (!pwrkey->input) {
238 		dev_dbg(&pdev->dev, "unable to allocate input device\n");
239 		return -ENOMEM;
240 	}
241 
242 	input_set_capability(pwrkey->input, EV_KEY, pwrkey->code);
243 
244 	pwrkey->input->name = "pm8941_pwrkey";
245 	pwrkey->input->phys = "pm8941_pwrkey/input0";
246 
247 	req_delay = (req_delay << 6) / USEC_PER_SEC;
248 	req_delay = ilog2(req_delay);
249 
250 	error = regmap_update_bits(pwrkey->regmap,
251 				   pwrkey->baseaddr + PON_DBC_CTL,
252 				   PON_DBC_DELAY_MASK,
253 				   req_delay);
254 	if (error) {
255 		dev_err(&pdev->dev, "failed to set debounce: %d\n", error);
256 		return error;
257 	}
258 
259 	error = regmap_update_bits(pwrkey->regmap,
260 				   pwrkey->baseaddr + PON_PULL_CTL,
261 				   pwrkey->data->pull_up_bit,
262 				   pull_up ? pwrkey->data->pull_up_bit : 0);
263 	if (error) {
264 		dev_err(&pdev->dev, "failed to set pull: %d\n", error);
265 		return error;
266 	}
267 
268 	error = devm_request_threaded_irq(&pdev->dev, pwrkey->irq,
269 					  NULL, pm8941_pwrkey_irq,
270 					  IRQF_ONESHOT,
271 					  "pm8941_pwrkey", pwrkey);
272 	if (error) {
273 		dev_err(&pdev->dev, "failed requesting IRQ: %d\n", error);
274 		return error;
275 	}
276 
277 	error = input_register_device(pwrkey->input);
278 	if (error) {
279 		dev_err(&pdev->dev, "failed to register input device: %d\n",
280 			error);
281 		return error;
282 	}
283 
284 	pwrkey->reboot_notifier.notifier_call = pm8941_reboot_notify,
285 	error = register_reboot_notifier(&pwrkey->reboot_notifier);
286 	if (error) {
287 		dev_err(&pdev->dev, "failed to register reboot notifier: %d\n",
288 			error);
289 		return error;
290 	}
291 
292 	platform_set_drvdata(pdev, pwrkey);
293 	device_init_wakeup(&pdev->dev, 1);
294 
295 	return 0;
296 }
297 
298 static int pm8941_pwrkey_remove(struct platform_device *pdev)
299 {
300 	struct pm8941_pwrkey *pwrkey = platform_get_drvdata(pdev);
301 
302 	unregister_reboot_notifier(&pwrkey->reboot_notifier);
303 
304 	return 0;
305 }
306 
307 static const struct pm8941_data pwrkey_data = {
308 	.pull_up_bit = PON_KPDPWR_PULL_UP,
309 	.status_bit = PON_KPDPWR_N_SET,
310 };
311 
312 static const struct pm8941_data resin_data = {
313 	.pull_up_bit = PON_RESIN_PULL_UP,
314 	.status_bit = PON_RESIN_N_SET,
315 };
316 
317 static const struct of_device_id pm8941_pwr_key_id_table[] = {
318 	{ .compatible = "qcom,pm8941-pwrkey", .data = &pwrkey_data },
319 	{ .compatible = "qcom,pm8941-resin", .data = &resin_data },
320 	{ }
321 };
322 MODULE_DEVICE_TABLE(of, pm8941_pwr_key_id_table);
323 
324 static struct platform_driver pm8941_pwrkey_driver = {
325 	.probe = pm8941_pwrkey_probe,
326 	.remove = pm8941_pwrkey_remove,
327 	.driver = {
328 		.name = "pm8941-pwrkey",
329 		.pm = &pm8941_pwr_key_pm_ops,
330 		.of_match_table = of_match_ptr(pm8941_pwr_key_id_table),
331 	},
332 };
333 module_platform_driver(pm8941_pwrkey_driver);
334 
335 MODULE_DESCRIPTION("PM8941 Power Key driver");
336 MODULE_LICENSE("GPL v2");
337