1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Power key driver for SiRF PrimaII
4 *
5 * Copyright (c) 2013 - 2014 Cambridge Silicon Radio Limited, a CSR plc group
6 * company.
7 */
8
9 #include <linux/module.h>
10 #include <linux/interrupt.h>
11 #include <linux/delay.h>
12 #include <linux/platform_device.h>
13 #include <linux/input.h>
14 #include <linux/rtc/sirfsoc_rtciobrg.h>
15 #include <linux/of.h>
16 #include <linux/workqueue.h>
17
18 struct sirfsoc_pwrc_drvdata {
19 u32 pwrc_base;
20 struct input_dev *input;
21 struct delayed_work work;
22 };
23
24 #define PWRC_ON_KEY_BIT (1 << 0)
25
26 #define PWRC_INT_STATUS 0xc
27 #define PWRC_INT_MASK 0x10
28 #define PWRC_PIN_STATUS 0x14
29 #define PWRC_KEY_DETECT_UP_TIME 20 /* ms*/
30
sirfsoc_pwrc_is_on_key_down(struct sirfsoc_pwrc_drvdata * pwrcdrv)31 static int sirfsoc_pwrc_is_on_key_down(struct sirfsoc_pwrc_drvdata *pwrcdrv)
32 {
33 u32 state = sirfsoc_rtc_iobrg_readl(pwrcdrv->pwrc_base +
34 PWRC_PIN_STATUS);
35 return !(state & PWRC_ON_KEY_BIT); /* ON_KEY is active low */
36 }
37
sirfsoc_pwrc_report_event(struct work_struct * work)38 static void sirfsoc_pwrc_report_event(struct work_struct *work)
39 {
40 struct sirfsoc_pwrc_drvdata *pwrcdrv =
41 container_of(work, struct sirfsoc_pwrc_drvdata, work.work);
42
43 if (sirfsoc_pwrc_is_on_key_down(pwrcdrv)) {
44 schedule_delayed_work(&pwrcdrv->work,
45 msecs_to_jiffies(PWRC_KEY_DETECT_UP_TIME));
46 } else {
47 input_event(pwrcdrv->input, EV_KEY, KEY_POWER, 0);
48 input_sync(pwrcdrv->input);
49 }
50 }
51
sirfsoc_pwrc_isr(int irq,void * dev_id)52 static irqreturn_t sirfsoc_pwrc_isr(int irq, void *dev_id)
53 {
54 struct sirfsoc_pwrc_drvdata *pwrcdrv = dev_id;
55 u32 int_status;
56
57 int_status = sirfsoc_rtc_iobrg_readl(pwrcdrv->pwrc_base +
58 PWRC_INT_STATUS);
59 sirfsoc_rtc_iobrg_writel(int_status & ~PWRC_ON_KEY_BIT,
60 pwrcdrv->pwrc_base + PWRC_INT_STATUS);
61
62 input_event(pwrcdrv->input, EV_KEY, KEY_POWER, 1);
63 input_sync(pwrcdrv->input);
64 schedule_delayed_work(&pwrcdrv->work,
65 msecs_to_jiffies(PWRC_KEY_DETECT_UP_TIME));
66
67 return IRQ_HANDLED;
68 }
69
sirfsoc_pwrc_toggle_interrupts(struct sirfsoc_pwrc_drvdata * pwrcdrv,bool enable)70 static void sirfsoc_pwrc_toggle_interrupts(struct sirfsoc_pwrc_drvdata *pwrcdrv,
71 bool enable)
72 {
73 u32 int_mask;
74
75 int_mask = sirfsoc_rtc_iobrg_readl(pwrcdrv->pwrc_base + PWRC_INT_MASK);
76 if (enable)
77 int_mask |= PWRC_ON_KEY_BIT;
78 else
79 int_mask &= ~PWRC_ON_KEY_BIT;
80 sirfsoc_rtc_iobrg_writel(int_mask, pwrcdrv->pwrc_base + PWRC_INT_MASK);
81 }
82
sirfsoc_pwrc_open(struct input_dev * input)83 static int sirfsoc_pwrc_open(struct input_dev *input)
84 {
85 struct sirfsoc_pwrc_drvdata *pwrcdrv = input_get_drvdata(input);
86
87 sirfsoc_pwrc_toggle_interrupts(pwrcdrv, true);
88
89 return 0;
90 }
91
sirfsoc_pwrc_close(struct input_dev * input)92 static void sirfsoc_pwrc_close(struct input_dev *input)
93 {
94 struct sirfsoc_pwrc_drvdata *pwrcdrv = input_get_drvdata(input);
95
96 sirfsoc_pwrc_toggle_interrupts(pwrcdrv, false);
97 cancel_delayed_work_sync(&pwrcdrv->work);
98 }
99
100 static const struct of_device_id sirfsoc_pwrc_of_match[] = {
101 { .compatible = "sirf,prima2-pwrc" },
102 {},
103 };
104 MODULE_DEVICE_TABLE(of, sirfsoc_pwrc_of_match);
105
sirfsoc_pwrc_probe(struct platform_device * pdev)106 static int sirfsoc_pwrc_probe(struct platform_device *pdev)
107 {
108 struct device_node *np = pdev->dev.of_node;
109 struct sirfsoc_pwrc_drvdata *pwrcdrv;
110 int irq;
111 int error;
112
113 pwrcdrv = devm_kzalloc(&pdev->dev, sizeof(struct sirfsoc_pwrc_drvdata),
114 GFP_KERNEL);
115 if (!pwrcdrv) {
116 dev_info(&pdev->dev, "Not enough memory for the device data\n");
117 return -ENOMEM;
118 }
119
120 /*
121 * We can't use of_iomap because pwrc is not mapped in memory,
122 * the so-called base address is only offset in rtciobrg
123 */
124 error = of_property_read_u32(np, "reg", &pwrcdrv->pwrc_base);
125 if (error) {
126 dev_err(&pdev->dev,
127 "unable to find base address of pwrc node in dtb\n");
128 return error;
129 }
130
131 pwrcdrv->input = devm_input_allocate_device(&pdev->dev);
132 if (!pwrcdrv->input)
133 return -ENOMEM;
134
135 pwrcdrv->input->name = "sirfsoc pwrckey";
136 pwrcdrv->input->phys = "pwrc/input0";
137 pwrcdrv->input->evbit[0] = BIT_MASK(EV_KEY);
138 input_set_capability(pwrcdrv->input, EV_KEY, KEY_POWER);
139
140 INIT_DELAYED_WORK(&pwrcdrv->work, sirfsoc_pwrc_report_event);
141
142 pwrcdrv->input->open = sirfsoc_pwrc_open;
143 pwrcdrv->input->close = sirfsoc_pwrc_close;
144
145 input_set_drvdata(pwrcdrv->input, pwrcdrv);
146
147 /* Make sure the device is quiesced */
148 sirfsoc_pwrc_toggle_interrupts(pwrcdrv, false);
149
150 irq = platform_get_irq(pdev, 0);
151 error = devm_request_irq(&pdev->dev, irq,
152 sirfsoc_pwrc_isr, 0,
153 "sirfsoc_pwrc_int", pwrcdrv);
154 if (error) {
155 dev_err(&pdev->dev, "unable to claim irq %d, error: %d\n",
156 irq, error);
157 return error;
158 }
159
160 error = input_register_device(pwrcdrv->input);
161 if (error) {
162 dev_err(&pdev->dev,
163 "unable to register input device, error: %d\n",
164 error);
165 return error;
166 }
167
168 dev_set_drvdata(&pdev->dev, pwrcdrv);
169 device_init_wakeup(&pdev->dev, 1);
170
171 return 0;
172 }
173
sirfsoc_pwrc_resume(struct device * dev)174 static int __maybe_unused sirfsoc_pwrc_resume(struct device *dev)
175 {
176 struct sirfsoc_pwrc_drvdata *pwrcdrv = dev_get_drvdata(dev);
177 struct input_dev *input = pwrcdrv->input;
178
179 /*
180 * Do not mask pwrc interrupt as we want pwrc work as a wakeup source
181 * if users touch X_ONKEY_B, see arch/arm/mach-prima2/pm.c
182 */
183 mutex_lock(&input->mutex);
184 if (input->users)
185 sirfsoc_pwrc_toggle_interrupts(pwrcdrv, true);
186 mutex_unlock(&input->mutex);
187
188 return 0;
189 }
190
191 static SIMPLE_DEV_PM_OPS(sirfsoc_pwrc_pm_ops, NULL, sirfsoc_pwrc_resume);
192
193 static struct platform_driver sirfsoc_pwrc_driver = {
194 .probe = sirfsoc_pwrc_probe,
195 .driver = {
196 .name = "sirfsoc-pwrc",
197 .pm = &sirfsoc_pwrc_pm_ops,
198 .of_match_table = sirfsoc_pwrc_of_match,
199 }
200 };
201
202 module_platform_driver(sirfsoc_pwrc_driver);
203
204 MODULE_LICENSE("GPL v2");
205 MODULE_AUTHOR("Binghua Duan <Binghua.Duan@csr.com>, Xianglong Du <Xianglong.Du@csr.com>");
206 MODULE_DESCRIPTION("CSR Prima2 PWRC Driver");
207 MODULE_ALIAS("platform:sirfsoc-pwrc");
208