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/device.h>
7 #include <linux/err.h>
8 #include <linux/init.h>
9 #include <linux/input.h>
10 #include <linux/interrupt.h>
11 #include <linux/io.h>
12 #include <linux/jiffies.h>
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/of.h>
16 #include <linux/of_address.h>
17 #include <linux/platform_device.h>
18 #include <linux/pm_wakeirq.h>
19 #include <linux/mfd/syscon.h>
20 #include <linux/regmap.h>
21 
22 #define SNVS_HPVIDR1_REG	0xF8
23 #define SNVS_LPSR_REG		0x4C	/* LP Status Register */
24 #define SNVS_LPCR_REG		0x38	/* LP Control Register */
25 #define SNVS_HPSR_REG		0x14
26 #define SNVS_HPSR_BTN		BIT(6)
27 #define SNVS_LPSR_SPO		BIT(18)
28 #define SNVS_LPCR_DEP_EN	BIT(5)
29 
30 #define DEBOUNCE_TIME		30
31 #define REPEAT_INTERVAL		60
32 
33 struct pwrkey_drv_data {
34 	struct regmap *snvs;
35 	int irq;
36 	int keycode;
37 	int keystate;  /* 1:pressed */
38 	int wakeup;
39 	struct timer_list check_timer;
40 	struct input_dev *input;
41 	u8 minor_rev;
42 };
43 
44 static void imx_imx_snvs_check_for_events(struct timer_list *t)
45 {
46 	struct pwrkey_drv_data *pdata = from_timer(pdata, t, check_timer);
47 	struct input_dev *input = pdata->input;
48 	u32 state;
49 
50 	regmap_read(pdata->snvs, SNVS_HPSR_REG, &state);
51 	state = state & SNVS_HPSR_BTN ? 1 : 0;
52 
53 	/* only report new event if status changed */
54 	if (state ^ pdata->keystate) {
55 		pdata->keystate = state;
56 		input_event(input, EV_KEY, pdata->keycode, state);
57 		input_sync(input);
58 		pm_relax(pdata->input->dev.parent);
59 	}
60 
61 	/* repeat check if pressed long */
62 	if (state) {
63 		mod_timer(&pdata->check_timer,
64 			  jiffies + msecs_to_jiffies(REPEAT_INTERVAL));
65 	}
66 }
67 
68 static irqreturn_t imx_snvs_pwrkey_interrupt(int irq, void *dev_id)
69 {
70 	struct platform_device *pdev = dev_id;
71 	struct pwrkey_drv_data *pdata = platform_get_drvdata(pdev);
72 	struct input_dev *input = pdata->input;
73 	u32 lp_status;
74 
75 	pm_wakeup_event(input->dev.parent, 0);
76 
77 	regmap_read(pdata->snvs, SNVS_LPSR_REG, &lp_status);
78 	if (lp_status & SNVS_LPSR_SPO) {
79 		if (pdata->minor_rev == 0) {
80 			/*
81 			 * The first generation i.MX6 SoCs only sends an
82 			 * interrupt on button release. To mimic power-key
83 			 * usage, we'll prepend a press event.
84 			 */
85 			input_report_key(input, pdata->keycode, 1);
86 			input_sync(input);
87 			input_report_key(input, pdata->keycode, 0);
88 			input_sync(input);
89 			pm_relax(input->dev.parent);
90 		} else {
91 			mod_timer(&pdata->check_timer,
92 			          jiffies + msecs_to_jiffies(DEBOUNCE_TIME));
93 		}
94 	}
95 
96 	/* clear SPO status */
97 	regmap_write(pdata->snvs, SNVS_LPSR_REG, SNVS_LPSR_SPO);
98 
99 	return IRQ_HANDLED;
100 }
101 
102 static void imx_snvs_pwrkey_act(void *pdata)
103 {
104 	struct pwrkey_drv_data *pd = pdata;
105 
106 	del_timer_sync(&pd->check_timer);
107 }
108 
109 static int imx_snvs_pwrkey_probe(struct platform_device *pdev)
110 {
111 	struct pwrkey_drv_data *pdata;
112 	struct input_dev *input;
113 	struct device_node *np;
114 	int error;
115 	u32 vid;
116 
117 	/* Get SNVS register Page */
118 	np = pdev->dev.of_node;
119 	if (!np)
120 		return -ENODEV;
121 
122 	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
123 	if (!pdata)
124 		return -ENOMEM;
125 
126 	pdata->snvs = syscon_regmap_lookup_by_phandle(np, "regmap");
127 	if (IS_ERR(pdata->snvs)) {
128 		dev_err(&pdev->dev, "Can't get snvs syscon\n");
129 		return PTR_ERR(pdata->snvs);
130 	}
131 
132 	if (of_property_read_u32(np, "linux,keycode", &pdata->keycode)) {
133 		pdata->keycode = KEY_POWER;
134 		dev_warn(&pdev->dev, "KEY_POWER without setting in dts\n");
135 	}
136 
137 	pdata->wakeup = of_property_read_bool(np, "wakeup-source");
138 
139 	pdata->irq = platform_get_irq(pdev, 0);
140 	if (pdata->irq < 0)
141 		return -EINVAL;
142 
143 	regmap_read(pdata->snvs, SNVS_HPVIDR1_REG, &vid);
144 	pdata->minor_rev = vid & 0xff;
145 
146 	regmap_update_bits(pdata->snvs, SNVS_LPCR_REG, SNVS_LPCR_DEP_EN, SNVS_LPCR_DEP_EN);
147 
148 	/* clear the unexpected interrupt before driver ready */
149 	regmap_write(pdata->snvs, SNVS_LPSR_REG, SNVS_LPSR_SPO);
150 
151 	timer_setup(&pdata->check_timer, imx_imx_snvs_check_for_events, 0);
152 
153 	input = devm_input_allocate_device(&pdev->dev);
154 	if (!input) {
155 		dev_err(&pdev->dev, "failed to allocate the input device\n");
156 		return -ENOMEM;
157 	}
158 
159 	input->name = pdev->name;
160 	input->phys = "snvs-pwrkey/input0";
161 	input->id.bustype = BUS_HOST;
162 
163 	input_set_capability(input, EV_KEY, pdata->keycode);
164 
165 	/* input customer action to cancel release timer */
166 	error = devm_add_action(&pdev->dev, imx_snvs_pwrkey_act, pdata);
167 	if (error) {
168 		dev_err(&pdev->dev, "failed to register remove action\n");
169 		return error;
170 	}
171 
172 	pdata->input = input;
173 	platform_set_drvdata(pdev, pdata);
174 
175 	error = devm_request_irq(&pdev->dev, pdata->irq,
176 			       imx_snvs_pwrkey_interrupt,
177 			       0, pdev->name, pdev);
178 
179 	if (error) {
180 		dev_err(&pdev->dev, "interrupt not available.\n");
181 		return error;
182 	}
183 
184 	error = input_register_device(input);
185 	if (error < 0) {
186 		dev_err(&pdev->dev, "failed to register input device\n");
187 		return error;
188 	}
189 
190 	device_init_wakeup(&pdev->dev, pdata->wakeup);
191 	error = dev_pm_set_wake_irq(&pdev->dev, pdata->irq);
192 	if (error)
193 		dev_err(&pdev->dev, "irq wake enable failed.\n");
194 
195 	return 0;
196 }
197 
198 static const struct of_device_id imx_snvs_pwrkey_ids[] = {
199 	{ .compatible = "fsl,sec-v4.0-pwrkey" },
200 	{ /* sentinel */ }
201 };
202 MODULE_DEVICE_TABLE(of, imx_snvs_pwrkey_ids);
203 
204 static struct platform_driver imx_snvs_pwrkey_driver = {
205 	.driver = {
206 		.name = "snvs_pwrkey",
207 		.of_match_table = imx_snvs_pwrkey_ids,
208 	},
209 	.probe = imx_snvs_pwrkey_probe,
210 };
211 module_platform_driver(imx_snvs_pwrkey_driver);
212 
213 MODULE_AUTHOR("Freescale Semiconductor");
214 MODULE_DESCRIPTION("i.MX snvs power key Driver");
215 MODULE_LICENSE("GPL");
216