1/*
  2 * Power key driver for SiRF PrimaII
  3 *
  4 * Copyright (c) 2013 - 2014 Cambridge Silicon Radio Limited, a CSR plc group
  5 * company.
  6 *
  7 * Licensed under GPLv2 or later.
  8 */
  9
 10#include <linux/module.h>
 11#include <linux/interrupt.h>
 12#include <linux/delay.h>
 13#include <linux/platform_device.h>
 14#include <linux/input.h>
 15#include <linux/rtc/sirfsoc_rtciobrg.h>
 16#include <linux/of.h>
 17#include <linux/workqueue.h>
 18
 19struct sirfsoc_pwrc_drvdata {
 20	u32			pwrc_base;
 21	struct input_dev	*input;
 22	struct delayed_work	work;
 23};
 24
 25#define PWRC_ON_KEY_BIT			(1 << 0)
 26
 27#define PWRC_INT_STATUS			0xc
 28#define PWRC_INT_MASK			0x10
 29#define PWRC_PIN_STATUS			0x14
 30#define PWRC_KEY_DETECT_UP_TIME		20	/* ms*/
 31
 32static int sirfsoc_pwrc_is_on_key_down(struct sirfsoc_pwrc_drvdata *pwrcdrv)
 33{
 34	u32 state = sirfsoc_rtc_iobrg_readl(pwrcdrv->pwrc_base +
 35							PWRC_PIN_STATUS);
 36	return !(state & PWRC_ON_KEY_BIT); /* ON_KEY is active low */
 37}
 38
 39static void sirfsoc_pwrc_report_event(struct work_struct *work)
 40{
 41	struct sirfsoc_pwrc_drvdata *pwrcdrv =
 42		container_of(work, struct sirfsoc_pwrc_drvdata, work.work);
 43
 44	if (sirfsoc_pwrc_is_on_key_down(pwrcdrv)) {
 45		schedule_delayed_work(&pwrcdrv->work,
 46			msecs_to_jiffies(PWRC_KEY_DETECT_UP_TIME));
 47	} else {
 48		input_event(pwrcdrv->input, EV_KEY, KEY_POWER, 0);
 49		input_sync(pwrcdrv->input);
 50	}
 51}
 52
 53static irqreturn_t sirfsoc_pwrc_isr(int irq, void *dev_id)
 54{
 55	struct sirfsoc_pwrc_drvdata *pwrcdrv = dev_id;
 56	u32 int_status;
 57
 58	int_status = sirfsoc_rtc_iobrg_readl(pwrcdrv->pwrc_base +
 59							PWRC_INT_STATUS);
 60	sirfsoc_rtc_iobrg_writel(int_status & ~PWRC_ON_KEY_BIT,
 61				 pwrcdrv->pwrc_base + PWRC_INT_STATUS);
 62
 63	input_event(pwrcdrv->input, EV_KEY, KEY_POWER, 1);
 64	input_sync(pwrcdrv->input);
 65	schedule_delayed_work(&pwrcdrv->work,
 66			      msecs_to_jiffies(PWRC_KEY_DETECT_UP_TIME));
 67
 68	return IRQ_HANDLED;
 69}
 70
 71static void sirfsoc_pwrc_toggle_interrupts(struct sirfsoc_pwrc_drvdata *pwrcdrv,
 72					   bool enable)
 73{
 74	u32 int_mask;
 75
 76	int_mask = sirfsoc_rtc_iobrg_readl(pwrcdrv->pwrc_base + PWRC_INT_MASK);
 77	if (enable)
 78		int_mask |= PWRC_ON_KEY_BIT;
 79	else
 80		int_mask &= ~PWRC_ON_KEY_BIT;
 81	sirfsoc_rtc_iobrg_writel(int_mask, pwrcdrv->pwrc_base + PWRC_INT_MASK);
 82}
 83
 84static int sirfsoc_pwrc_open(struct input_dev *input)
 85{
 86	struct sirfsoc_pwrc_drvdata *pwrcdrv = input_get_drvdata(input);
 87
 88	sirfsoc_pwrc_toggle_interrupts(pwrcdrv, true);
 89
 90	return 0;
 91}
 92
 93static void sirfsoc_pwrc_close(struct input_dev *input)
 94{
 95	struct sirfsoc_pwrc_drvdata *pwrcdrv = input_get_drvdata(input);
 96
 97	sirfsoc_pwrc_toggle_interrupts(pwrcdrv, false);
 98	cancel_delayed_work_sync(&pwrcdrv->work);
 99}
100
101static const struct of_device_id sirfsoc_pwrc_of_match[] = {
102	{ .compatible = "sirf,prima2-pwrc" },
103	{},
104}
105MODULE_DEVICE_TABLE(of, sirfsoc_pwrc_of_match);
106
107static int sirfsoc_pwrc_probe(struct platform_device *pdev)
108{
109	struct device_node *np = pdev->dev.of_node;
110	struct sirfsoc_pwrc_drvdata *pwrcdrv;
111	int irq;
112	int error;
113
114	pwrcdrv = devm_kzalloc(&pdev->dev, sizeof(struct sirfsoc_pwrc_drvdata),
115			       GFP_KERNEL);
116	if (!pwrcdrv) {
117		dev_info(&pdev->dev, "Not enough memory for the device data\n");
118		return -ENOMEM;
119	}
120
121	/*
122	 * We can't use of_iomap because pwrc is not mapped in memory,
123	 * the so-called base address is only offset in rtciobrg
124	 */
125	error = of_property_read_u32(np, "reg", &pwrcdrv->pwrc_base);
126	if (error) {
127		dev_err(&pdev->dev,
128			"unable to find base address of pwrc node in dtb\n");
129		return error;
130	}
131
132	pwrcdrv->input = devm_input_allocate_device(&pdev->dev);
133	if (!pwrcdrv->input)
134		return -ENOMEM;
135
136	pwrcdrv->input->name = "sirfsoc pwrckey";
137	pwrcdrv->input->phys = "pwrc/input0";
138	pwrcdrv->input->evbit[0] = BIT_MASK(EV_KEY);
139	input_set_capability(pwrcdrv->input, EV_KEY, KEY_POWER);
140
141	INIT_DELAYED_WORK(&pwrcdrv->work, sirfsoc_pwrc_report_event);
142
143	pwrcdrv->input->open = sirfsoc_pwrc_open;
144	pwrcdrv->input->close = sirfsoc_pwrc_close;
145
146	input_set_drvdata(pwrcdrv->input, pwrcdrv);
147
148	/* Make sure the device is quiesced */
149	sirfsoc_pwrc_toggle_interrupts(pwrcdrv, false);
150
151	irq = platform_get_irq(pdev, 0);
152	error = devm_request_irq(&pdev->dev, irq,
153				 sirfsoc_pwrc_isr, 0,
154				 "sirfsoc_pwrc_int", pwrcdrv);
155	if (error) {
156		dev_err(&pdev->dev, "unable to claim irq %d, error: %d\n",
157			irq, error);
158		return error;
159	}
160
161	error = input_register_device(pwrcdrv->input);
162	if (error) {
163		dev_err(&pdev->dev,
164			"unable to register input device, error: %d\n",
165			error);
166		return error;
167	}
168
169	dev_set_drvdata(&pdev->dev, pwrcdrv);
170	device_init_wakeup(&pdev->dev, 1);
171
172	return 0;
173}
174
175static int sirfsoc_pwrc_remove(struct platform_device *pdev)
176{
177	device_init_wakeup(&pdev->dev, 0);
178
179	return 0;
180}
181
182#ifdef CONFIG_PM_SLEEP
183static int sirfsoc_pwrc_resume(struct device *dev)
184{
185	struct sirfsoc_pwrc_drvdata *pwrcdrv = dev_get_drvdata(dev);
186	struct input_dev *input = pwrcdrv->input;
187
188	/*
189	 * Do not mask pwrc interrupt as we want pwrc work as a wakeup source
190	 * if users touch X_ONKEY_B, see arch/arm/mach-prima2/pm.c
191	 */
192	mutex_lock(&input->mutex);
193	if (input->users)
194		sirfsoc_pwrc_toggle_interrupts(pwrcdrv, true);
195	mutex_unlock(&input->mutex);
196
197	return 0;
198}
199#endif
200
201static SIMPLE_DEV_PM_OPS(sirfsoc_pwrc_pm_ops, NULL, sirfsoc_pwrc_resume);
202
203static struct platform_driver sirfsoc_pwrc_driver = {
204	.probe		= sirfsoc_pwrc_probe,
205	.remove		= sirfsoc_pwrc_remove,
206	.driver		= {
207		.name	= "sirfsoc-pwrc",
208		.owner	= THIS_MODULE,
209		.pm	= &sirfsoc_pwrc_pm_ops,
210		.of_match_table = sirfsoc_pwrc_of_match,
211	}
212};
213
214module_platform_driver(sirfsoc_pwrc_driver);
215
216MODULE_LICENSE("GPLv2");
217MODULE_AUTHOR("Binghua Duan <Binghua.Duan@csr.com>, Xianglong Du <Xianglong.Du@csr.com>");
218MODULE_DESCRIPTION("CSR Prima2 PWRC Driver");
219MODULE_ALIAS("platform:sirfsoc-pwrc");