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 
22 struct clps711x_gpio_data {
23 	struct gpio_desc *desc;
24 	DECLARE_BITMAP(last_state, CLPS711X_KEYPAD_COL_COUNT);
25 };
26 
27 struct 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 
clps711x_keypad_poll(struct input_dev * input)34 static 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 
clps711x_keypad_probe(struct platform_device * pdev)87 static 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 
168 static const struct of_device_id clps711x_keypad_of_match[] = {
169 	{ .compatible = "cirrus,ep7209-keypad", },
170 	{ }
171 };
172 MODULE_DEVICE_TABLE(of, clps711x_keypad_of_match);
173 
174 static 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 };
181 module_platform_driver(clps711x_keypad_driver);
182 
183 MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
184 MODULE_DESCRIPTION("Cirrus Logic CLPS711X Keypad driver");
185 MODULE_LICENSE("GPL");
186