1/*
  2 * Driver for the IMX SNVS ON/OFF Power Key
  3 * Copyright (C) 2015 Freescale Semiconductor, Inc. All Rights Reserved.
  4 *
  5 * The code contained herein is licensed under the GNU General Public
  6 * License. You may obtain a copy of the GNU General Public License
  7 * Version 2 or later at the following locations:
  8 *
  9 * http://www.opensource.org/licenses/gpl-license.html
 10 * http://www.gnu.org/copyleft/gpl.html
 11 */
 12
 13#include <linux/device.h>
 14#include <linux/err.h>
 15#include <linux/init.h>
 16#include <linux/input.h>
 17#include <linux/interrupt.h>
 18#include <linux/io.h>
 19#include <linux/jiffies.h>
 20#include <linux/kernel.h>
 21#include <linux/module.h>
 22#include <linux/of.h>
 23#include <linux/of_address.h>
 24#include <linux/platform_device.h>
 25#include <linux/mfd/syscon.h>
 26#include <linux/regmap.h>
 27
 28#define SNVS_LPSR_REG	0x4C	/* LP Status Register */
 29#define SNVS_LPCR_REG	0x38	/* LP Control Register */
 30#define SNVS_HPSR_REG	0x14
 31#define SNVS_HPSR_BTN	BIT(6)
 32#define SNVS_LPSR_SPO	BIT(18)
 33#define SNVS_LPCR_DEP_EN BIT(5)
 34
 35#define DEBOUNCE_TIME 30
 36#define REPEAT_INTERVAL 60
 37
 38struct pwrkey_drv_data {
 39	struct regmap *snvs;
 40	int irq;
 41	int keycode;
 42	int keystate;  /* 1:pressed */
 43	int wakeup;
 44	struct timer_list check_timer;
 45	struct input_dev *input;
 46};
 47
 48static void imx_imx_snvs_check_for_events(unsigned long data)
 49{
 50	struct pwrkey_drv_data *pdata = (struct pwrkey_drv_data *) data;
 51	struct input_dev *input = pdata->input;
 52	u32 state;
 53
 54	regmap_read(pdata->snvs, SNVS_HPSR_REG, &state);
 55	state = state & SNVS_HPSR_BTN ? 1 : 0;
 56
 57	/* only report new event if status changed */
 58	if (state ^ pdata->keystate) {
 59		pdata->keystate = state;
 60		input_event(input, EV_KEY, pdata->keycode, state);
 61		input_sync(input);
 62		pm_relax(pdata->input->dev.parent);
 63	}
 64
 65	/* repeat check if pressed long */
 66	if (state) {
 67		mod_timer(&pdata->check_timer,
 68			  jiffies + msecs_to_jiffies(REPEAT_INTERVAL));
 69	}
 70}
 71
 72static irqreturn_t imx_snvs_pwrkey_interrupt(int irq, void *dev_id)
 73{
 74	struct platform_device *pdev = dev_id;
 75	struct pwrkey_drv_data *pdata = platform_get_drvdata(pdev);
 76	u32 lp_status;
 77
 78	pm_wakeup_event(pdata->input->dev.parent, 0);
 79
 80	regmap_read(pdata->snvs, SNVS_LPSR_REG, &lp_status);
 81	if (lp_status & SNVS_LPSR_SPO)
 82		mod_timer(&pdata->check_timer, jiffies + msecs_to_jiffies(DEBOUNCE_TIME));
 83
 84	/* clear SPO status */
 85	regmap_write(pdata->snvs, SNVS_LPSR_REG, SNVS_LPSR_SPO);
 86
 87	return IRQ_HANDLED;
 88}
 89
 90static void imx_snvs_pwrkey_act(void *pdata)
 91{
 92	struct pwrkey_drv_data *pd = pdata;
 93
 94	del_timer_sync(&pd->check_timer);
 95}
 96
 97static int imx_snvs_pwrkey_probe(struct platform_device *pdev)
 98{
 99	struct pwrkey_drv_data *pdata = NULL;
100	struct input_dev *input = NULL;
101	struct device_node *np;
102	int error;
103
104	/* Get SNVS register Page */
105	np = pdev->dev.of_node;
106	if (!np)
107		return -ENODEV;
108
109	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
110	if (!pdata)
111		return -ENOMEM;
112
113	pdata->snvs = syscon_regmap_lookup_by_phandle(np, "regmap");
114	if (IS_ERR(pdata->snvs)) {
115		dev_err(&pdev->dev, "Can't get snvs syscon\n");
116		return PTR_ERR(pdata->snvs);
117	}
118
119	if (of_property_read_u32(np, "linux,keycode", &pdata->keycode)) {
120		pdata->keycode = KEY_POWER;
121		dev_warn(&pdev->dev, "KEY_POWER without setting in dts\n");
122	}
123
124	pdata->wakeup = of_property_read_bool(np, "wakeup-source");
125
126	pdata->irq = platform_get_irq(pdev, 0);
127	if (pdata->irq < 0) {
128		dev_err(&pdev->dev, "no irq defined in platform data\n");
129		return -EINVAL;
130	}
131
132	regmap_update_bits(pdata->snvs, SNVS_LPCR_REG, SNVS_LPCR_DEP_EN, SNVS_LPCR_DEP_EN);
133
134	/* clear the unexpected interrupt before driver ready */
135	regmap_write(pdata->snvs, SNVS_LPSR_REG, SNVS_LPSR_SPO);
136
137	setup_timer(&pdata->check_timer,
138		    imx_imx_snvs_check_for_events, (unsigned long) pdata);
139
140	input = devm_input_allocate_device(&pdev->dev);
141	if (!input) {
142		dev_err(&pdev->dev, "failed to allocate the input device\n");
143		return -ENOMEM;
144	}
145
146	input->name = pdev->name;
147	input->phys = "snvs-pwrkey/input0";
148	input->id.bustype = BUS_HOST;
149
150	input_set_capability(input, EV_KEY, pdata->keycode);
151
152	/* input customer action to cancel release timer */
153	error = devm_add_action(&pdev->dev, imx_snvs_pwrkey_act, pdata);
154	if (error) {
155		dev_err(&pdev->dev, "failed to register remove action\n");
156		return error;
157	}
158
159	error = devm_request_irq(&pdev->dev, pdata->irq,
160			       imx_snvs_pwrkey_interrupt,
161			       0, pdev->name, pdev);
162
163	if (error) {
164		dev_err(&pdev->dev, "interrupt not available.\n");
165		return error;
166	}
167
168	error = input_register_device(input);
169	if (error < 0) {
170		dev_err(&pdev->dev, "failed to register input device\n");
171		input_free_device(input);
172		return error;
173	}
174
175	pdata->input = input;
176	platform_set_drvdata(pdev, pdata);
177
178	device_init_wakeup(&pdev->dev, pdata->wakeup);
179
180	return 0;
181}
182
183static int __maybe_unused imx_snvs_pwrkey_suspend(struct device *dev)
184{
185	struct platform_device *pdev = to_platform_device(dev);
186	struct pwrkey_drv_data *pdata = platform_get_drvdata(pdev);
187
188	if (device_may_wakeup(&pdev->dev))
189		enable_irq_wake(pdata->irq);
190
191	return 0;
192}
193
194static int __maybe_unused imx_snvs_pwrkey_resume(struct device *dev)
195{
196	struct platform_device *pdev = to_platform_device(dev);
197	struct pwrkey_drv_data *pdata = platform_get_drvdata(pdev);
198
199	if (device_may_wakeup(&pdev->dev))
200		disable_irq_wake(pdata->irq);
201
202	return 0;
203}
204
205static const struct of_device_id imx_snvs_pwrkey_ids[] = {
206	{ .compatible = "fsl,sec-v4.0-pwrkey" },
207	{ /* sentinel */ }
208};
209MODULE_DEVICE_TABLE(of, imx_snvs_pwrkey_ids);
210
211static SIMPLE_DEV_PM_OPS(imx_snvs_pwrkey_pm_ops, imx_snvs_pwrkey_suspend,
212				imx_snvs_pwrkey_resume);
213
214static struct platform_driver imx_snvs_pwrkey_driver = {
215	.driver = {
216		.name = "snvs_pwrkey",
217		.pm     = &imx_snvs_pwrkey_pm_ops,
218		.of_match_table = imx_snvs_pwrkey_ids,
219	},
220	.probe = imx_snvs_pwrkey_probe,
221};
222module_platform_driver(imx_snvs_pwrkey_driver);
223
224MODULE_AUTHOR("Freescale Semiconductor");
225MODULE_DESCRIPTION("i.MX snvs power key Driver");
226MODULE_LICENSE("GPL");