snvs_pwrkey.c

  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
 36struct 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
 47static 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
 72static 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
106static 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
113static 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
231static const struct of_device_id imx_snvs_pwrkey_ids[] = {
232	{ .compatible = "fsl,sec-v4.0-pwrkey" },
233	{ /* sentinel */ }
234};
235MODULE_DEVICE_TABLE(of, imx_snvs_pwrkey_ids);
236
237static 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};
244module_platform_driver(imx_snvs_pwrkey_driver);
245
246MODULE_AUTHOR("Freescale Semiconductor");
247MODULE_DESCRIPTION("i.MX snvs power key Driver");
248MODULE_LICENSE("GPL");