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 #define SNVS_LPCR_BPT_SHIFT 16
31 #define SNVS_LPCR_BPT_MASK (3 << SNVS_LPCR_BPT_SHIFT)
32
33 #define DEBOUNCE_TIME 30
34 #define REPEAT_INTERVAL 60
35
36 struct pwrkey_drv_data {
37 struct regmap *snvs;
38 int irq;
39 int keycode;
40 int keystate; /* 1:pressed */
41 int wakeup;
42 struct timer_list check_timer;
43 struct input_dev *input;
44 u8 minor_rev;
45 };
46
imx_imx_snvs_check_for_events(struct timer_list * t)47 static void imx_imx_snvs_check_for_events(struct timer_list *t)
48 {
49 struct pwrkey_drv_data *pdata = timer_container_of(pdata, t,
50 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
imx_snvs_pwrkey_interrupt(int irq,void * dev_id)72 static 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 struct input_dev *input = pdata->input;
77 u32 lp_status;
78
79 pm_wakeup_event(input->dev.parent, 0);
80
81 regmap_read(pdata->snvs, SNVS_LPSR_REG, &lp_status);
82 if (lp_status & SNVS_LPSR_SPO) {
83 if (pdata->minor_rev == 0) {
84 /*
85 * The first generation i.MX6 SoCs only sends an
86 * interrupt on button release. To mimic power-key
87 * usage, we'll prepend a press event.
88 */
89 input_report_key(input, pdata->keycode, 1);
90 input_sync(input);
91 input_report_key(input, pdata->keycode, 0);
92 input_sync(input);
93 pm_relax(input->dev.parent);
94 } else {
95 mod_timer(&pdata->check_timer,
96 jiffies + msecs_to_jiffies(DEBOUNCE_TIME));
97 }
98 }
99
100 /* clear SPO status */
101 regmap_write(pdata->snvs, SNVS_LPSR_REG, SNVS_LPSR_SPO);
102
103 return IRQ_HANDLED;
104 }
105
imx_snvs_pwrkey_act(void * pdata)106 static void imx_snvs_pwrkey_act(void *pdata)
107 {
108 struct pwrkey_drv_data *pd = pdata;
109
110 timer_delete_sync(&pd->check_timer);
111 }
112
imx_snvs_pwrkey_probe(struct platform_device * pdev)113 static int imx_snvs_pwrkey_probe(struct platform_device *pdev)
114 {
115 struct pwrkey_drv_data *pdata;
116 struct input_dev *input;
117 struct device_node *np;
118 struct clk *clk;
119 int error;
120 unsigned int val;
121 unsigned int bpt;
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_enabled(&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 pdata->wakeup = of_property_read_bool(np, "wakeup-source");
151
152 pdata->irq = platform_get_irq(pdev, 0);
153 if (pdata->irq < 0)
154 return -EINVAL;
155
156 error = of_property_read_u32(np, "power-off-time-sec", &val);
157 if (!error) {
158 switch (val) {
159 case 0:
160 bpt = 0x3;
161 break;
162 case 5:
163 case 10:
164 case 15:
165 bpt = (val / 5) - 1;
166 break;
167 default:
168 dev_err(&pdev->dev,
169 "power-off-time-sec %d out of range\n", val);
170 return -EINVAL;
171 }
172
173 regmap_update_bits(pdata->snvs, SNVS_LPCR_REG, SNVS_LPCR_BPT_MASK,
174 bpt << SNVS_LPCR_BPT_SHIFT);
175 }
176
177 regmap_read(pdata->snvs, SNVS_HPVIDR1_REG, &vid);
178 pdata->minor_rev = vid & 0xff;
179
180 regmap_update_bits(pdata->snvs, SNVS_LPCR_REG, SNVS_LPCR_DEP_EN, SNVS_LPCR_DEP_EN);
181
182 /* clear the unexpected interrupt before driver ready */
183 regmap_write(pdata->snvs, SNVS_LPSR_REG, SNVS_LPSR_SPO);
184
185 timer_setup(&pdata->check_timer, imx_imx_snvs_check_for_events, 0);
186
187 input = devm_input_allocate_device(&pdev->dev);
188 if (!input) {
189 dev_err(&pdev->dev, "failed to allocate the input device\n");
190 return -ENOMEM;
191 }
192
193 input->name = pdev->name;
194 input->phys = "snvs-pwrkey/input0";
195 input->id.bustype = BUS_HOST;
196
197 input_set_capability(input, EV_KEY, pdata->keycode);
198
199 /* input customer action to cancel release timer */
200 error = devm_add_action(&pdev->dev, imx_snvs_pwrkey_act, pdata);
201 if (error) {
202 dev_err(&pdev->dev, "failed to register remove action\n");
203 return error;
204 }
205
206 pdata->input = input;
207 platform_set_drvdata(pdev, pdata);
208
209 error = devm_request_irq(&pdev->dev, pdata->irq,
210 imx_snvs_pwrkey_interrupt,
211 0, pdev->name, pdev);
212 if (error) {
213 dev_err(&pdev->dev, "interrupt not available.\n");
214 return error;
215 }
216
217 error = input_register_device(input);
218 if (error < 0) {
219 dev_err(&pdev->dev, "failed to register input device\n");
220 return error;
221 }
222
223 device_init_wakeup(&pdev->dev, pdata->wakeup);
224 error = dev_pm_set_wake_irq(&pdev->dev, pdata->irq);
225 if (error)
226 dev_err(&pdev->dev, "irq wake enable failed.\n");
227
228 return 0;
229 }
230
231 static const struct of_device_id imx_snvs_pwrkey_ids[] = {
232 { .compatible = "fsl,sec-v4.0-pwrkey" },
233 { /* sentinel */ }
234 };
235 MODULE_DEVICE_TABLE(of, imx_snvs_pwrkey_ids);
236
237 static struct platform_driver imx_snvs_pwrkey_driver = {
238 .driver = {
239 .name = "snvs_pwrkey",
240 .of_match_table = imx_snvs_pwrkey_ids,
241 },
242 .probe = imx_snvs_pwrkey_probe,
243 };
244 module_platform_driver(imx_snvs_pwrkey_driver);
245
246 MODULE_AUTHOR("Freescale Semiconductor");
247 MODULE_DESCRIPTION("i.MX snvs power key Driver");
248 MODULE_LICENSE("GPL");
249