1// SPDX-License-Identifier: GPL-2.0+
2//
3// Driver for the IMX SNVS ON/OFF Power Key
4// Copyright (C) 2015 Freescale Semiconductor, Inc. All Rights Reserved.
5
6#include <linux/clk.h>
7#include <linux/device.h>
8#include <linux/err.h>
9#include <linux/init.h>
10#include <linux/input.h>
11#include <linux/interrupt.h>
12#include <linux/io.h>
13#include <linux/jiffies.h>
14#include <linux/kernel.h>
15#include <linux/module.h>
16#include <linux/of.h>
17#include <linux/of_address.h>
18#include <linux/platform_device.h>
19#include <linux/pm_wakeirq.h>
20#include <linux/mfd/syscon.h>
21#include <linux/regmap.h>
22
23#define SNVS_HPVIDR1_REG	0xBF8
24#define SNVS_LPSR_REG		0x4C	/* LP Status Register */
25#define SNVS_LPCR_REG		0x38	/* LP Control Register */
26#define SNVS_HPSR_REG		0x14
27#define SNVS_HPSR_BTN		BIT(6)
28#define SNVS_LPSR_SPO		BIT(18)
29#define SNVS_LPCR_DEP_EN	BIT(5)
30
31#define DEBOUNCE_TIME		30
32#define REPEAT_INTERVAL		60
33
34struct pwrkey_drv_data {
35	struct regmap *snvs;
36	int irq;
37	int keycode;
38	int keystate;  /* 1:pressed */
39	int wakeup;
40	struct timer_list check_timer;
41	struct input_dev *input;
42	u8 minor_rev;
43};
44
45static void imx_imx_snvs_check_for_events(struct timer_list *t)
46{
47	struct pwrkey_drv_data *pdata = from_timer(pdata, t, check_timer);
48	struct input_dev *input = pdata->input;
49	u32 state;
50
51	regmap_read(pdata->snvs, SNVS_HPSR_REG, &state);
52	state = state & SNVS_HPSR_BTN ? 1 : 0;
53
54	/* only report new event if status changed */
55	if (state ^ pdata->keystate) {
56		pdata->keystate = state;
57		input_event(input, EV_KEY, pdata->keycode, state);
58		input_sync(input);
59		pm_relax(pdata->input->dev.parent);
60	}
61
62	/* repeat check if pressed long */
63	if (state) {
64		mod_timer(&pdata->check_timer,
65			  jiffies + msecs_to_jiffies(REPEAT_INTERVAL));
66	}
67}
68
69static irqreturn_t imx_snvs_pwrkey_interrupt(int irq, void *dev_id)
70{
71	struct platform_device *pdev = dev_id;
72	struct pwrkey_drv_data *pdata = platform_get_drvdata(pdev);
73	struct input_dev *input = pdata->input;
74	u32 lp_status;
75
76	pm_wakeup_event(input->dev.parent, 0);
77
78	regmap_read(pdata->snvs, SNVS_LPSR_REG, &lp_status);
79	if (lp_status & SNVS_LPSR_SPO) {
80		if (pdata->minor_rev == 0) {
81			/*
82			 * The first generation i.MX6 SoCs only sends an
83			 * interrupt on button release. To mimic power-key
84			 * usage, we'll prepend a press event.
85			 */
86			input_report_key(input, pdata->keycode, 1);
87			input_sync(input);
88			input_report_key(input, pdata->keycode, 0);
89			input_sync(input);
90			pm_relax(input->dev.parent);
91		} else {
92			mod_timer(&pdata->check_timer,
93			          jiffies + msecs_to_jiffies(DEBOUNCE_TIME));
94		}
95	}
96
97	/* clear SPO status */
98	regmap_write(pdata->snvs, SNVS_LPSR_REG, SNVS_LPSR_SPO);
99
100	return IRQ_HANDLED;
101}
102
103static void imx_snvs_pwrkey_disable_clk(void *data)
104{
105	clk_disable_unprepare(data);
106}
107
108static void imx_snvs_pwrkey_act(void *pdata)
109{
110	struct pwrkey_drv_data *pd = pdata;
111
112	del_timer_sync(&pd->check_timer);
113}
114
115static int imx_snvs_pwrkey_probe(struct platform_device *pdev)
116{
117	struct pwrkey_drv_data *pdata;
118	struct input_dev *input;
119	struct device_node *np;
120	struct clk *clk;
121	int error;
122	u32 vid;
123
124	/* Get SNVS register Page */
125	np = pdev->dev.of_node;
126	if (!np)
127		return -ENODEV;
128
129	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
130	if (!pdata)
131		return -ENOMEM;
132
133	pdata->snvs = syscon_regmap_lookup_by_phandle(np, "regmap");
134	if (IS_ERR(pdata->snvs)) {
135		dev_err(&pdev->dev, "Can't get snvs syscon\n");
136		return PTR_ERR(pdata->snvs);
137	}
138
139	if (of_property_read_u32(np, "linux,keycode", &pdata->keycode)) {
140		pdata->keycode = KEY_POWER;
141		dev_warn(&pdev->dev, "KEY_POWER without setting in dts\n");
142	}
143
144	clk = devm_clk_get_optional(&pdev->dev, NULL);
145	if (IS_ERR(clk)) {
146		dev_err(&pdev->dev, "Failed to get snvs clock (%pe)\n", clk);
147		return PTR_ERR(clk);
148	}
149
150	error = clk_prepare_enable(clk);
151	if (error) {
152		dev_err(&pdev->dev, "Failed to enable snvs clock (%pe)\n",
153			ERR_PTR(error));
154		return error;
155	}
156
157	error = devm_add_action_or_reset(&pdev->dev,
158					 imx_snvs_pwrkey_disable_clk, clk);
159	if (error) {
160		dev_err(&pdev->dev,
161			"Failed to register clock cleanup handler (%pe)\n",
162			ERR_PTR(error));
163		return error;
164	}
165
166	pdata->wakeup = of_property_read_bool(np, "wakeup-source");
167
168	pdata->irq = platform_get_irq(pdev, 0);
169	if (pdata->irq < 0)
170		return -EINVAL;
171
172	regmap_read(pdata->snvs, SNVS_HPVIDR1_REG, &vid);
173	pdata->minor_rev = vid & 0xff;
174
175	regmap_update_bits(pdata->snvs, SNVS_LPCR_REG, SNVS_LPCR_DEP_EN, SNVS_LPCR_DEP_EN);
176
177	/* clear the unexpected interrupt before driver ready */
178	regmap_write(pdata->snvs, SNVS_LPSR_REG, SNVS_LPSR_SPO);
179
180	timer_setup(&pdata->check_timer, imx_imx_snvs_check_for_events, 0);
181
182	input = devm_input_allocate_device(&pdev->dev);
183	if (!input) {
184		dev_err(&pdev->dev, "failed to allocate the input device\n");
185		return -ENOMEM;
186	}
187
188	input->name = pdev->name;
189	input->phys = "snvs-pwrkey/input0";
190	input->id.bustype = BUS_HOST;
191
192	input_set_capability(input, EV_KEY, pdata->keycode);
193
194	/* input customer action to cancel release timer */
195	error = devm_add_action(&pdev->dev, imx_snvs_pwrkey_act, pdata);
196	if (error) {
197		dev_err(&pdev->dev, "failed to register remove action\n");
198		return error;
199	}
200
201	pdata->input = input;
202	platform_set_drvdata(pdev, pdata);
203
204	error = devm_request_irq(&pdev->dev, pdata->irq,
205			       imx_snvs_pwrkey_interrupt,
206			       0, pdev->name, pdev);
207
208	if (error) {
209		dev_err(&pdev->dev, "interrupt not available.\n");
210		return error;
211	}
212
213	error = input_register_device(input);
214	if (error < 0) {
215		dev_err(&pdev->dev, "failed to register input device\n");
216		return error;
217	}
218
219	device_init_wakeup(&pdev->dev, pdata->wakeup);
220	error = dev_pm_set_wake_irq(&pdev->dev, pdata->irq);
221	if (error)
222		dev_err(&pdev->dev, "irq wake enable failed.\n");
223
224	return 0;
225}
226
227static const struct of_device_id imx_snvs_pwrkey_ids[] = {
228	{ .compatible = "fsl,sec-v4.0-pwrkey" },
229	{ /* sentinel */ }
230};
231MODULE_DEVICE_TABLE(of, imx_snvs_pwrkey_ids);
232
233static struct platform_driver imx_snvs_pwrkey_driver = {
234	.driver = {
235		.name = "snvs_pwrkey",
236		.of_match_table = imx_snvs_pwrkey_ids,
237	},
238	.probe = imx_snvs_pwrkey_probe,
239};
240module_platform_driver(imx_snvs_pwrkey_driver);
241
242MODULE_AUTHOR("Freescale Semiconductor");
243MODULE_DESCRIPTION("i.MX snvs power key Driver");
244MODULE_LICENSE("GPL");
245