tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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(struct timer_list *t)
49{
50 struct pwrkey_drv_data *pdata = from_timer(pdata, t, check_timer);
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 timer_setup(&pdata->check_timer, imx_imx_snvs_check_for_events, 0);
138
139 input = devm_input_allocate_device(&pdev->dev);
140 if (!input) {
141 dev_err(&pdev->dev, "failed to allocate the input device\n");
142 return -ENOMEM;
143 }
144
145 input->name = pdev->name;
146 input->phys = "snvs-pwrkey/input0";
147 input->id.bustype = BUS_HOST;
148
149 input_set_capability(input, EV_KEY, pdata->keycode);
150
151 /* input customer action to cancel release timer */
152 error = devm_add_action(&pdev->dev, imx_snvs_pwrkey_act, pdata);
153 if (error) {
154 dev_err(&pdev->dev, "failed to register remove action\n");
155 return error;
156 }
157
158 error = devm_request_irq(&pdev->dev, pdata->irq,
159 imx_snvs_pwrkey_interrupt,
160 0, pdev->name, pdev);
161
162 if (error) {
163 dev_err(&pdev->dev, "interrupt not available.\n");
164 return error;
165 }
166
167 error = input_register_device(input);
168 if (error < 0) {
169 dev_err(&pdev->dev, "failed to register input device\n");
170 return error;
171 }
172
173 pdata->input = input;
174 platform_set_drvdata(pdev, pdata);
175
176 device_init_wakeup(&pdev->dev, pdata->wakeup);
177
178 return 0;
179}
180
181static int __maybe_unused imx_snvs_pwrkey_suspend(struct device *dev)
182{
183 struct platform_device *pdev = to_platform_device(dev);
184 struct pwrkey_drv_data *pdata = platform_get_drvdata(pdev);
185
186 if (device_may_wakeup(&pdev->dev))
187 enable_irq_wake(pdata->irq);
188
189 return 0;
190}
191
192static int __maybe_unused imx_snvs_pwrkey_resume(struct device *dev)
193{
194 struct platform_device *pdev = to_platform_device(dev);
195 struct pwrkey_drv_data *pdata = platform_get_drvdata(pdev);
196
197 if (device_may_wakeup(&pdev->dev))
198 disable_irq_wake(pdata->irq);
199
200 return 0;
201}
202
203static const struct of_device_id imx_snvs_pwrkey_ids[] = {
204 { .compatible = "fsl,sec-v4.0-pwrkey" },
205 { /* sentinel */ }
206};
207MODULE_DEVICE_TABLE(of, imx_snvs_pwrkey_ids);
208
209static SIMPLE_DEV_PM_OPS(imx_snvs_pwrkey_pm_ops, imx_snvs_pwrkey_suspend,
210 imx_snvs_pwrkey_resume);
211
212static struct platform_driver imx_snvs_pwrkey_driver = {
213 .driver = {
214 .name = "snvs_pwrkey",
215 .pm = &imx_snvs_pwrkey_pm_ops,
216 .of_match_table = imx_snvs_pwrkey_ids,
217 },
218 .probe = imx_snvs_pwrkey_probe,
219};
220module_platform_driver(imx_snvs_pwrkey_driver);
221
222MODULE_AUTHOR("Freescale Semiconductor");
223MODULE_DESCRIPTION("i.MX snvs power key Driver");
224MODULE_LICENSE("GPL");