1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Cirrus Logic CLPS711X Keypad driver
4 *
5 * Copyright (C) 2014 Alexander Shiyan <shc_work@mail.ru>
6 */
7
8#include <linux/input.h>
9#include <linux/mod_devicetable.h>
10#include <linux/module.h>
11#include <linux/gpio/consumer.h>
12#include <linux/platform_device.h>
13#include <linux/property.h>
14#include <linux/regmap.h>
15#include <linux/sched.h>
16#include <linux/input/matrix_keypad.h>
17#include <linux/mfd/syscon.h>
18#include <linux/mfd/syscon/clps711x.h>
19
20#define CLPS711X_KEYPAD_COL_COUNT	8
21
22struct clps711x_gpio_data {
23	struct gpio_desc *desc;
24	DECLARE_BITMAP(last_state, CLPS711X_KEYPAD_COL_COUNT);
25};
26
27struct clps711x_keypad_data {
28	struct regmap			*syscon;
29	int				row_count;
30	unsigned int			row_shift;
31	struct clps711x_gpio_data	*gpio_data;
32};
33
34static void clps711x_keypad_poll(struct input_dev *input)
35{
36	const unsigned short *keycodes = input->keycode;
37	struct clps711x_keypad_data *priv = input_get_drvdata(input);
38	bool sync = false;
39	int col, row;
40
41	for (col = 0; col < CLPS711X_KEYPAD_COL_COUNT; col++) {
42		/* Assert column */
43		regmap_update_bits(priv->syscon, SYSCON_OFFSET,
44				   SYSCON1_KBDSCAN_MASK,
45				   SYSCON1_KBDSCAN(8 + col));
46
47		/* Scan rows */
48		for (row = 0; row < priv->row_count; row++) {
49			struct clps711x_gpio_data *data = &priv->gpio_data[row];
50			bool state, state1;
51
52			/* Read twice for protection against fluctuations */
53			do {
54				state = gpiod_get_value_cansleep(data->desc);
55				cond_resched();
56				state1 = gpiod_get_value_cansleep(data->desc);
57			} while (state != state1);
58
59			if (test_bit(col, data->last_state) != state) {
60				int code = MATRIX_SCAN_CODE(row, col,
61							    priv->row_shift);
62
63				if (state) {
64					set_bit(col, data->last_state);
65					input_event(input,
66						    EV_MSC, MSC_SCAN, code);
67				} else {
68					clear_bit(col, data->last_state);
69				}
70
71				if (keycodes[code])
72					input_report_key(input,
73							 keycodes[code], state);
74				sync = true;
75			}
76		}
77
78		/* Set all columns to low */
79		regmap_update_bits(priv->syscon, SYSCON_OFFSET,
80				   SYSCON1_KBDSCAN_MASK, SYSCON1_KBDSCAN(1));
81	}
82
83	if (sync)
84		input_sync(input);
85}
86
87static int clps711x_keypad_probe(struct platform_device *pdev)
88{
89	struct clps711x_keypad_data *priv;
90	struct device *dev = &pdev->dev;
91	struct input_dev *input;
92	u32 poll_interval;
93	int i, err;
94
95	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
96	if (!priv)
97		return -ENOMEM;
98
99	priv->syscon = syscon_regmap_lookup_by_phandle(dev->of_node, "syscon");
100	if (IS_ERR(priv->syscon))
101		return PTR_ERR(priv->syscon);
102
103	priv->row_count = gpiod_count(dev, "row");
104	if (priv->row_count < 1)
105		return -EINVAL;
106
107	priv->gpio_data = devm_kcalloc(dev,
108				priv->row_count, sizeof(*priv->gpio_data),
109				GFP_KERNEL);
110	if (!priv->gpio_data)
111		return -ENOMEM;
112
113	priv->row_shift = get_count_order(CLPS711X_KEYPAD_COL_COUNT);
114
115	for (i = 0; i < priv->row_count; i++) {
116		struct clps711x_gpio_data *data = &priv->gpio_data[i];
117
118		data->desc = devm_gpiod_get_index(dev, "row", i, GPIOD_IN);
119		if (IS_ERR(data->desc))
120			return PTR_ERR(data->desc);
121	}
122
123	err = device_property_read_u32(dev, "poll-interval", &poll_interval);
124	if (err)
125		return err;
126
127	input = devm_input_allocate_device(dev);
128	if (!input)
129		return -ENOMEM;
130
131	input_set_drvdata(input, priv);
132
133	input->name		= pdev->name;
134	input->dev.parent	= dev;
135	input->id.bustype	= BUS_HOST;
136	input->id.vendor	= 0x0001;
137	input->id.product	= 0x0001;
138	input->id.version	= 0x0100;
139
140	err = matrix_keypad_build_keymap(NULL, NULL, priv->row_count,
141					 CLPS711X_KEYPAD_COL_COUNT,
142					 NULL, input);
143	if (err)
144		return err;
145
146	input_set_capability(input, EV_MSC, MSC_SCAN);
147	if (device_property_read_bool(dev, "autorepeat"))
148		__set_bit(EV_REP, input->evbit);
149
150	/* Set all columns to low */
151	regmap_update_bits(priv->syscon, SYSCON_OFFSET, SYSCON1_KBDSCAN_MASK,
152			   SYSCON1_KBDSCAN(1));
153
154
155	err = input_setup_polling(input, clps711x_keypad_poll);
156	if (err)
157		return err;
158
159	input_set_poll_interval(input, poll_interval);
160
161	err = input_register_device(input);
162	if (err)
163		return err;
164
165	return 0;
166}
167
168static const struct of_device_id clps711x_keypad_of_match[] = {
169	{ .compatible = "cirrus,ep7209-keypad", },
170	{ }
171};
172MODULE_DEVICE_TABLE(of, clps711x_keypad_of_match);
173
174static struct platform_driver clps711x_keypad_driver = {
175	.driver	= {
176		.name		= "clps711x-keypad",
177		.of_match_table	= clps711x_keypad_of_match,
178	},
179	.probe	= clps711x_keypad_probe,
180};
181module_platform_driver(clps711x_keypad_driver);
182
183MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
184MODULE_DESCRIPTION("Cirrus Logic CLPS711X Keypad driver");
185MODULE_LICENSE("GPL");
186