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_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 };
42
imx_imx_snvs_check_for_events(struct timer_list * t)43 static void imx_imx_snvs_check_for_events(struct timer_list *t)
44 {
45 struct pwrkey_drv_data *pdata = from_timer(pdata, t, check_timer);
46 struct input_dev *input = pdata->input;
47 u32 state;
48
49 regmap_read(pdata->snvs, SNVS_HPSR_REG, &state);
50 state = state & SNVS_HPSR_BTN ? 1 : 0;
51
52 /* only report new event if status changed */
53 if (state ^ pdata->keystate) {
54 pdata->keystate = state;
55 input_event(input, EV_KEY, pdata->keycode, state);
56 input_sync(input);
57 pm_relax(pdata->input->dev.parent);
58 }
59
60 /* repeat check if pressed long */
61 if (state) {
62 mod_timer(&pdata->check_timer,
63 jiffies + msecs_to_jiffies(REPEAT_INTERVAL));
64 }
65 }
66
imx_snvs_pwrkey_interrupt(int irq,void * dev_id)67 static irqreturn_t imx_snvs_pwrkey_interrupt(int irq, void *dev_id)
68 {
69 struct platform_device *pdev = dev_id;
70 struct pwrkey_drv_data *pdata = platform_get_drvdata(pdev);
71 u32 lp_status;
72
73 pm_wakeup_event(pdata->input->dev.parent, 0);
74
75 regmap_read(pdata->snvs, SNVS_LPSR_REG, &lp_status);
76 if (lp_status & SNVS_LPSR_SPO)
77 mod_timer(&pdata->check_timer, jiffies + msecs_to_jiffies(DEBOUNCE_TIME));
78
79 /* clear SPO status */
80 regmap_write(pdata->snvs, SNVS_LPSR_REG, SNVS_LPSR_SPO);
81
82 return IRQ_HANDLED;
83 }
84
imx_snvs_pwrkey_disable_clk(void * data)85 static void imx_snvs_pwrkey_disable_clk(void *data)
86 {
87 clk_disable_unprepare(data);
88 }
89
imx_snvs_pwrkey_act(void * pdata)90 static 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
imx_snvs_pwrkey_probe(struct platform_device * pdev)97 static 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 struct clk *clk;
103 int error;
104
105 /* Get SNVS register Page */
106 np = pdev->dev.of_node;
107 if (!np)
108 return -ENODEV;
109
110 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
111 if (!pdata)
112 return -ENOMEM;
113
114 pdata->snvs = syscon_regmap_lookup_by_phandle(np, "regmap");
115 if (IS_ERR(pdata->snvs)) {
116 dev_err(&pdev->dev, "Can't get snvs syscon\n");
117 return PTR_ERR(pdata->snvs);
118 }
119
120 if (of_property_read_u32(np, "linux,keycode", &pdata->keycode)) {
121 pdata->keycode = KEY_POWER;
122 dev_warn(&pdev->dev, "KEY_POWER without setting in dts\n");
123 }
124
125 clk = devm_clk_get_optional(&pdev->dev, NULL);
126 if (IS_ERR(clk)) {
127 dev_err(&pdev->dev, "Failed to get snvs clock (%pe)\n", clk);
128 return PTR_ERR(clk);
129 }
130
131 error = clk_prepare_enable(clk);
132 if (error) {
133 dev_err(&pdev->dev, "Failed to enable snvs clock (%pe)\n",
134 ERR_PTR(error));
135 return error;
136 }
137
138 error = devm_add_action_or_reset(&pdev->dev,
139 imx_snvs_pwrkey_disable_clk, clk);
140 if (error) {
141 dev_err(&pdev->dev,
142 "Failed to register clock cleanup handler (%pe)\n",
143 ERR_PTR(error));
144 return error;
145 }
146
147 pdata->wakeup = of_property_read_bool(np, "wakeup-source");
148
149 pdata->irq = platform_get_irq(pdev, 0);
150 if (pdata->irq < 0)
151 return -EINVAL;
152
153 regmap_update_bits(pdata->snvs, SNVS_LPCR_REG, SNVS_LPCR_DEP_EN, SNVS_LPCR_DEP_EN);
154
155 /* clear the unexpected interrupt before driver ready */
156 regmap_write(pdata->snvs, SNVS_LPSR_REG, SNVS_LPSR_SPO);
157
158 timer_setup(&pdata->check_timer, imx_imx_snvs_check_for_events, 0);
159
160 input = devm_input_allocate_device(&pdev->dev);
161 if (!input) {
162 dev_err(&pdev->dev, "failed to allocate the input device\n");
163 return -ENOMEM;
164 }
165
166 input->name = pdev->name;
167 input->phys = "snvs-pwrkey/input0";
168 input->id.bustype = BUS_HOST;
169
170 input_set_capability(input, EV_KEY, pdata->keycode);
171
172 /* input customer action to cancel release timer */
173 error = devm_add_action(&pdev->dev, imx_snvs_pwrkey_act, pdata);
174 if (error) {
175 dev_err(&pdev->dev, "failed to register remove action\n");
176 return error;
177 }
178
179 pdata->input = input;
180 platform_set_drvdata(pdev, pdata);
181
182 error = devm_request_irq(&pdev->dev, pdata->irq,
183 imx_snvs_pwrkey_interrupt,
184 0, pdev->name, pdev);
185
186 if (error) {
187 dev_err(&pdev->dev, "interrupt not available.\n");
188 return error;
189 }
190
191 error = input_register_device(input);
192 if (error < 0) {
193 dev_err(&pdev->dev, "failed to register input device\n");
194 return error;
195 }
196
197 device_init_wakeup(&pdev->dev, pdata->wakeup);
198 error = dev_pm_set_wake_irq(&pdev->dev, pdata->irq);
199 if (error)
200 dev_err(&pdev->dev, "irq wake enable failed.\n");
201
202 return 0;
203 }
204
205 static const struct of_device_id imx_snvs_pwrkey_ids[] = {
206 { .compatible = "fsl,sec-v4.0-pwrkey" },
207 { /* sentinel */ }
208 };
209 MODULE_DEVICE_TABLE(of, imx_snvs_pwrkey_ids);
210
211 static struct platform_driver imx_snvs_pwrkey_driver = {
212 .driver = {
213 .name = "snvs_pwrkey",
214 .of_match_table = imx_snvs_pwrkey_ids,
215 },
216 .probe = imx_snvs_pwrkey_probe,
217 };
218 module_platform_driver(imx_snvs_pwrkey_driver);
219
220 MODULE_AUTHOR("Freescale Semiconductor");
221 MODULE_DESCRIPTION("i.MX snvs power key Driver");
222 MODULE_LICENSE("GPL");
223