1 /*
2  * Cirrus Logic CLPS711X Keypad driver
3  *
4  * Copyright (C) 2014 Alexander Shiyan <shc_work@mail.ru>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  */
11 
12 #include <linux/input.h>
13 #include <linux/input-polldev.h>
14 #include <linux/module.h>
15 #include <linux/of_gpio.h>
16 #include <linux/platform_device.h>
17 #include <linux/regmap.h>
18 #include <linux/sched.h>
19 #include <linux/input/matrix_keypad.h>
20 #include <linux/mfd/syscon.h>
21 #include <linux/mfd/syscon/clps711x.h>
22 
23 #define CLPS711X_KEYPAD_COL_COUNT	8
24 
25 struct clps711x_gpio_data {
26 	struct gpio_desc *desc;
27 	DECLARE_BITMAP(last_state, CLPS711X_KEYPAD_COL_COUNT);
28 };
29 
30 struct clps711x_keypad_data {
31 	struct regmap			*syscon;
32 	int				row_count;
33 	unsigned int			row_shift;
34 	struct clps711x_gpio_data	*gpio_data;
35 };
36 
37 static void clps711x_keypad_poll(struct input_polled_dev *dev)
38 {
39 	const unsigned short *keycodes = dev->input->keycode;
40 	struct clps711x_keypad_data *priv = dev->private;
41 	bool sync = false;
42 	int col, row;
43 
44 	for (col = 0; col < CLPS711X_KEYPAD_COL_COUNT; col++) {
45 		/* Assert column */
46 		regmap_update_bits(priv->syscon, SYSCON_OFFSET,
47 				   SYSCON1_KBDSCAN_MASK,
48 				   SYSCON1_KBDSCAN(8 + col));
49 
50 		/* Scan rows */
51 		for (row = 0; row < priv->row_count; row++) {
52 			struct clps711x_gpio_data *data = &priv->gpio_data[row];
53 			bool state, state1;
54 
55 			/* Read twice for protection against fluctuations */
56 			do {
57 				state = gpiod_get_value_cansleep(data->desc);
58 				cond_resched();
59 				state1 = gpiod_get_value_cansleep(data->desc);
60 			} while (state != state1);
61 
62 			if (test_bit(col, data->last_state) != state) {
63 				int code = MATRIX_SCAN_CODE(row, col,
64 							    priv->row_shift);
65 
66 				if (state) {
67 					set_bit(col, data->last_state);
68 					input_event(dev->input, EV_MSC,
69 						    MSC_SCAN, code);
70 				} else {
71 					clear_bit(col, data->last_state);
72 				}
73 
74 				if (keycodes[code])
75 					input_report_key(dev->input,
76 							 keycodes[code], state);
77 				sync = true;
78 			}
79 		}
80 
81 		/* Set all columns to low */
82 		regmap_update_bits(priv->syscon, SYSCON_OFFSET,
83 				   SYSCON1_KBDSCAN_MASK, SYSCON1_KBDSCAN(1));
84 	}
85 
86 	if (sync)
87 		input_sync(dev->input);
88 }
89 
90 static int clps711x_keypad_probe(struct platform_device *pdev)
91 {
92 	struct clps711x_keypad_data *priv;
93 	struct device *dev = &pdev->dev;
94 	struct device_node *np = dev->of_node;
95 	struct input_polled_dev *poll_dev;
96 	u32 poll_interval;
97 	int i, err;
98 
99 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
100 	if (!priv)
101 		return -ENOMEM;
102 
103 	priv->syscon =
104 		syscon_regmap_lookup_by_compatible("cirrus,ep7209-syscon1");
105 	if (IS_ERR(priv->syscon))
106 		return PTR_ERR(priv->syscon);
107 
108 	priv->row_count = of_gpio_named_count(np, "row-gpios");
109 	if (priv->row_count < 1)
110 		return -EINVAL;
111 
112 	priv->gpio_data = devm_kcalloc(dev,
113 				priv->row_count, sizeof(*priv->gpio_data),
114 				GFP_KERNEL);
115 	if (!priv->gpio_data)
116 		return -ENOMEM;
117 
118 	priv->row_shift = get_count_order(CLPS711X_KEYPAD_COL_COUNT);
119 
120 	for (i = 0; i < priv->row_count; i++) {
121 		struct clps711x_gpio_data *data = &priv->gpio_data[i];
122 
123 		data->desc = devm_gpiod_get_index(dev, "row", i, GPIOD_IN);
124 		if (IS_ERR(data->desc))
125 			return PTR_ERR(data->desc);
126 	}
127 
128 	err = of_property_read_u32(np, "poll-interval", &poll_interval);
129 	if (err)
130 		return err;
131 
132 	poll_dev = input_allocate_polled_device();
133 	if (!poll_dev)
134 		return -ENOMEM;
135 
136 	poll_dev->private		= priv;
137 	poll_dev->poll			= clps711x_keypad_poll;
138 	poll_dev->poll_interval		= poll_interval;
139 	poll_dev->input->name		= pdev->name;
140 	poll_dev->input->dev.parent	= dev;
141 	poll_dev->input->id.bustype	= BUS_HOST;
142 	poll_dev->input->id.vendor	= 0x0001;
143 	poll_dev->input->id.product	= 0x0001;
144 	poll_dev->input->id.version	= 0x0100;
145 
146 	err = matrix_keypad_build_keymap(NULL, NULL, priv->row_count,
147 					 CLPS711X_KEYPAD_COL_COUNT,
148 					 NULL, poll_dev->input);
149 	if (err)
150 		goto out_err;
151 
152 	input_set_capability(poll_dev->input, EV_MSC, MSC_SCAN);
153 	if (of_property_read_bool(np, "autorepeat"))
154 		__set_bit(EV_REP, poll_dev->input->evbit);
155 
156 	platform_set_drvdata(pdev, poll_dev);
157 
158 	/* Set all columns to low */
159 	regmap_update_bits(priv->syscon, SYSCON_OFFSET, SYSCON1_KBDSCAN_MASK,
160 			   SYSCON1_KBDSCAN(1));
161 
162 	err = input_register_polled_device(poll_dev);
163 	if (err)
164 		goto out_err;
165 
166 	return 0;
167 
168 out_err:
169 	input_free_polled_device(poll_dev);
170 	return err;
171 }
172 
173 static int clps711x_keypad_remove(struct platform_device *pdev)
174 {
175 	struct input_polled_dev *poll_dev = platform_get_drvdata(pdev);
176 
177 	input_unregister_polled_device(poll_dev);
178 	input_free_polled_device(poll_dev);
179 
180 	return 0;
181 }
182 
183 static const struct of_device_id clps711x_keypad_of_match[] = {
184 	{ .compatible = "cirrus,ep7209-keypad", },
185 	{ }
186 };
187 MODULE_DEVICE_TABLE(of, clps711x_keypad_of_match);
188 
189 static struct platform_driver clps711x_keypad_driver = {
190 	.driver	= {
191 		.name		= "clps711x-keypad",
192 		.of_match_table	= clps711x_keypad_of_match,
193 	},
194 	.probe	= clps711x_keypad_probe,
195 	.remove	= clps711x_keypad_remove,
196 };
197 module_platform_driver(clps711x_keypad_driver);
198 
199 MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
200 MODULE_DESCRIPTION("Cirrus Logic CLPS711X Keypad driver");
201 MODULE_LICENSE("GPL");
202