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/input-polldev.h>
10 #include <linux/module.h>
11 #include <linux/of_gpio.h>
12 #include <linux/platform_device.h>
13 #include <linux/regmap.h>
14 #include <linux/sched.h>
15 #include <linux/input/matrix_keypad.h>
16 #include <linux/mfd/syscon.h>
17 #include <linux/mfd/syscon/clps711x.h>
18 
19 #define CLPS711X_KEYPAD_COL_COUNT	8
20 
21 struct clps711x_gpio_data {
22 	struct gpio_desc *desc;
23 	DECLARE_BITMAP(last_state, CLPS711X_KEYPAD_COL_COUNT);
24 };
25 
26 struct clps711x_keypad_data {
27 	struct regmap			*syscon;
28 	int				row_count;
29 	unsigned int			row_shift;
30 	struct clps711x_gpio_data	*gpio_data;
31 };
32 
33 static void clps711x_keypad_poll(struct input_polled_dev *dev)
34 {
35 	const unsigned short *keycodes = dev->input->keycode;
36 	struct clps711x_keypad_data *priv = dev->private;
37 	bool sync = false;
38 	int col, row;
39 
40 	for (col = 0; col < CLPS711X_KEYPAD_COL_COUNT; col++) {
41 		/* Assert column */
42 		regmap_update_bits(priv->syscon, SYSCON_OFFSET,
43 				   SYSCON1_KBDSCAN_MASK,
44 				   SYSCON1_KBDSCAN(8 + col));
45 
46 		/* Scan rows */
47 		for (row = 0; row < priv->row_count; row++) {
48 			struct clps711x_gpio_data *data = &priv->gpio_data[row];
49 			bool state, state1;
50 
51 			/* Read twice for protection against fluctuations */
52 			do {
53 				state = gpiod_get_value_cansleep(data->desc);
54 				cond_resched();
55 				state1 = gpiod_get_value_cansleep(data->desc);
56 			} while (state != state1);
57 
58 			if (test_bit(col, data->last_state) != state) {
59 				int code = MATRIX_SCAN_CODE(row, col,
60 							    priv->row_shift);
61 
62 				if (state) {
63 					set_bit(col, data->last_state);
64 					input_event(dev->input, EV_MSC,
65 						    MSC_SCAN, code);
66 				} else {
67 					clear_bit(col, data->last_state);
68 				}
69 
70 				if (keycodes[code])
71 					input_report_key(dev->input,
72 							 keycodes[code], state);
73 				sync = true;
74 			}
75 		}
76 
77 		/* Set all columns to low */
78 		regmap_update_bits(priv->syscon, SYSCON_OFFSET,
79 				   SYSCON1_KBDSCAN_MASK, SYSCON1_KBDSCAN(1));
80 	}
81 
82 	if (sync)
83 		input_sync(dev->input);
84 }
85 
86 static int clps711x_keypad_probe(struct platform_device *pdev)
87 {
88 	struct clps711x_keypad_data *priv;
89 	struct device *dev = &pdev->dev;
90 	struct device_node *np = dev->of_node;
91 	struct input_polled_dev *poll_dev;
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 =
100 		syscon_regmap_lookup_by_compatible("cirrus,ep7209-syscon1");
101 	if (IS_ERR(priv->syscon))
102 		return PTR_ERR(priv->syscon);
103 
104 	priv->row_count = of_gpio_named_count(np, "row-gpios");
105 	if (priv->row_count < 1)
106 		return -EINVAL;
107 
108 	priv->gpio_data = devm_kcalloc(dev,
109 				priv->row_count, sizeof(*priv->gpio_data),
110 				GFP_KERNEL);
111 	if (!priv->gpio_data)
112 		return -ENOMEM;
113 
114 	priv->row_shift = get_count_order(CLPS711X_KEYPAD_COL_COUNT);
115 
116 	for (i = 0; i < priv->row_count; i++) {
117 		struct clps711x_gpio_data *data = &priv->gpio_data[i];
118 
119 		data->desc = devm_gpiod_get_index(dev, "row", i, GPIOD_IN);
120 		if (IS_ERR(data->desc))
121 			return PTR_ERR(data->desc);
122 	}
123 
124 	err = of_property_read_u32(np, "poll-interval", &poll_interval);
125 	if (err)
126 		return err;
127 
128 	poll_dev = input_allocate_polled_device();
129 	if (!poll_dev)
130 		return -ENOMEM;
131 
132 	poll_dev->private		= priv;
133 	poll_dev->poll			= clps711x_keypad_poll;
134 	poll_dev->poll_interval		= poll_interval;
135 	poll_dev->input->name		= pdev->name;
136 	poll_dev->input->dev.parent	= dev;
137 	poll_dev->input->id.bustype	= BUS_HOST;
138 	poll_dev->input->id.vendor	= 0x0001;
139 	poll_dev->input->id.product	= 0x0001;
140 	poll_dev->input->id.version	= 0x0100;
141 
142 	err = matrix_keypad_build_keymap(NULL, NULL, priv->row_count,
143 					 CLPS711X_KEYPAD_COL_COUNT,
144 					 NULL, poll_dev->input);
145 	if (err)
146 		goto out_err;
147 
148 	input_set_capability(poll_dev->input, EV_MSC, MSC_SCAN);
149 	if (of_property_read_bool(np, "autorepeat"))
150 		__set_bit(EV_REP, poll_dev->input->evbit);
151 
152 	platform_set_drvdata(pdev, poll_dev);
153 
154 	/* Set all columns to low */
155 	regmap_update_bits(priv->syscon, SYSCON_OFFSET, SYSCON1_KBDSCAN_MASK,
156 			   SYSCON1_KBDSCAN(1));
157 
158 	err = input_register_polled_device(poll_dev);
159 	if (err)
160 		goto out_err;
161 
162 	return 0;
163 
164 out_err:
165 	input_free_polled_device(poll_dev);
166 	return err;
167 }
168 
169 static int clps711x_keypad_remove(struct platform_device *pdev)
170 {
171 	struct input_polled_dev *poll_dev = platform_get_drvdata(pdev);
172 
173 	input_unregister_polled_device(poll_dev);
174 	input_free_polled_device(poll_dev);
175 
176 	return 0;
177 }
178 
179 static const struct of_device_id clps711x_keypad_of_match[] = {
180 	{ .compatible = "cirrus,ep7209-keypad", },
181 	{ }
182 };
183 MODULE_DEVICE_TABLE(of, clps711x_keypad_of_match);
184 
185 static struct platform_driver clps711x_keypad_driver = {
186 	.driver	= {
187 		.name		= "clps711x-keypad",
188 		.of_match_table	= clps711x_keypad_of_match,
189 	},
190 	.probe	= clps711x_keypad_probe,
191 	.remove	= clps711x_keypad_remove,
192 };
193 module_platform_driver(clps711x_keypad_driver);
194 
195 MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
196 MODULE_DESCRIPTION("Cirrus Logic CLPS711X Keypad driver");
197 MODULE_LICENSE("GPL");
198