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
 18struct 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
 31static 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
 38static 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
 52static 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
 70static 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
 83static 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
 92static 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
100static const struct of_device_id sirfsoc_pwrc_of_match[] = {
101	{ .compatible = "sirf,prima2-pwrc" },
102	{},
103};
104MODULE_DEVICE_TABLE(of, sirfsoc_pwrc_of_match);
105
106static 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
174static 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
191static SIMPLE_DEV_PM_OPS(sirfsoc_pwrc_pm_ops, NULL, sirfsoc_pwrc_resume);
192
193static 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
202module_platform_driver(sirfsoc_pwrc_driver);
203
204MODULE_LICENSE("GPL v2");
205MODULE_AUTHOR("Binghua Duan <Binghua.Duan@csr.com>, Xianglong Du <Xianglong.Du@csr.com>");
206MODULE_DESCRIPTION("CSR Prima2 PWRC Driver");
207MODULE_ALIAS("platform:sirfsoc-pwrc");