summaryrefslogtreecommitdiff
path: root/drivers/input/cros_ec_keyb.c
blob: 8c1a25c73f772e9f3282b3b477d3467f11b6dd6b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
// SPDX-License-Identifier: GPL-2.0+
/*
 * Chromium OS Matrix Keyboard
 *
 * Copyright (c) 2012 The Chromium OS Authors.
 */

#include <common.h>
#include <cros_ec.h>
#include <dm.h>
#include <errno.h>
#include <input.h>
#include <keyboard.h>
#include <key_matrix.h>
#include <stdio_dev.h>

enum {
	KBC_MAX_KEYS		= 8,	/* Maximum keys held down at once */
	KBC_REPEAT_RATE_MS	= 30,
	KBC_REPEAT_DELAY_MS	= 240,
};

struct cros_ec_keyb_priv {
	struct input_config *input;	/* The input layer */
	struct key_matrix matrix;	/* The key matrix layer */
	int key_rows;			/* Number of keyboard rows */
	int key_cols;			/* Number of keyboard columns */
	int ghost_filter;		/* 1 to enable ghost filter, else 0 */
};


/**
 * Check the keyboard controller and return a list of key matrix positions
 * for which a key is pressed
 *
 * @param dev		Keyboard device
 * @param keys		List of keys that we have detected
 * @param max_count	Maximum number of keys to return
 * @param samep		Set to true if this scan repeats the last, else false
 * @return number of pressed keys, 0 for none, -EIO on error
 */
static int check_for_keys(struct udevice *dev, struct key_matrix_key *keys,
			  int max_count, bool *samep)
{
	struct cros_ec_keyb_priv *priv = dev_get_priv(dev);
	struct key_matrix_key *key;
	static struct mbkp_keyscan last_scan;
	static bool last_scan_valid;
	struct mbkp_keyscan scan;
	unsigned int row, col, bit, data;
	int num_keys;

	if (cros_ec_scan_keyboard(dev->parent, &scan)) {
		debug("%s: keyboard scan failed\n", __func__);
		return -EIO;
	}
	*samep = last_scan_valid && !memcmp(&last_scan, &scan, sizeof(scan));

	/*
	 * This is a bit odd. The EC has no way to tell us that it has run
	 * out of key scans. It just returns the same scan over and over
	 * again. So the only way to detect that we have run out is to detect
	 * that this scan is the same as the last.
	 */
	last_scan_valid = true;
	memcpy(&last_scan, &scan, sizeof(last_scan));

	for (col = num_keys = bit = 0; col < priv->matrix.num_cols;
			col++) {
		for (row = 0; row < priv->matrix.num_rows; row++) {
			unsigned int mask = 1 << (bit & 7);

			data = scan.data[bit / 8];
			if ((data & mask) && num_keys < max_count) {
				key = keys + num_keys++;
				key->row = row;
				key->col = col;
				key->valid = 1;
			}
			bit++;
		}
	}

	return num_keys;
}

/**
 * Check the keyboard, and send any keys that are pressed.
 *
 * This is called by input_tstc() and input_getc() when they need more
 * characters
 *
 * @param input		Input configuration
 * @return 1, to indicate that we have something to look at
 */
int cros_ec_kbc_check(struct input_config *input)
{
	struct udevice *dev = input->dev;
	struct cros_ec_keyb_priv *priv = dev_get_priv(dev);
	static struct key_matrix_key last_keys[KBC_MAX_KEYS];
	static int last_num_keys;
	struct key_matrix_key keys[KBC_MAX_KEYS];
	int keycodes[KBC_MAX_KEYS];
	int num_keys, num_keycodes;
	int irq_pending, sent;
	bool same = false;

	/*
	 * Loop until the EC has no more keyscan records, or we have
	 * received at least one character. This means we know that tstc()
	 * will always return non-zero if keys have been pressed.
	 *
	 * Without this loop, a key release (which generates no new ascii
	 * characters) will cause us to exit this function, and just tstc()
	 * may return 0 before all keys have been read from the EC.
	 */
	do {
		irq_pending = cros_ec_interrupt_pending(dev->parent);
		if (irq_pending) {
			num_keys = check_for_keys(dev, keys, KBC_MAX_KEYS,
						  &same);
			if (num_keys < 0)
				return 0;
			last_num_keys = num_keys;
			memcpy(last_keys, keys, sizeof(keys));
		} else {
			/*
			 * EC doesn't want to be asked, so use keys from last
			 * time.
			 */
			num_keys = last_num_keys;
			memcpy(keys, last_keys, sizeof(keys));
		}

		if (num_keys < 0)
			return -1;
		num_keycodes = key_matrix_decode(&priv->matrix, keys,
				num_keys, keycodes, KBC_MAX_KEYS);
		sent = input_send_keycodes(input, keycodes, num_keycodes);

		/*
		 * For those ECs without an interrupt, stop scanning when we
		 * see that the scan is the same as last time.
		 */
		if ((irq_pending < 0) && same)
			break;
	} while (irq_pending && !sent);

	return 1;
}

/**
 * Decode MBKP keyboard details from the device tree
 *
 * @param blob		Device tree blob
 * @param node		Node to decode from
 * @param config	Configuration data read from fdt
 * @return 0 if ok, -1 on error
 */
static int cros_ec_keyb_decode_fdt(struct udevice *dev,
				   struct cros_ec_keyb_priv *config)
{
	/*
	 * Get keyboard rows and columns - at present we are limited to
	 * 8 columns by the protocol (one byte per row scan)
	 */
	config->key_rows = dev_read_u32_default(dev, "keypad,num-rows", 0);
	config->key_cols = dev_read_u32_default(dev, "keypad,num-columns", 0);
	if (!config->key_rows || !config->key_cols ||
			config->key_rows * config->key_cols / 8
				> CROS_EC_KEYSCAN_COLS) {
		debug("%s: Invalid key matrix size %d x %d\n", __func__,
		      config->key_rows, config->key_cols);
		return -1;
	}
	config->ghost_filter = dev_read_bool(dev, "google,needs-ghost-filter");

	return 0;
}

static int cros_ec_kbd_probe(struct udevice *dev)
{
	struct cros_ec_keyb_priv *priv = dev_get_priv(dev);
	struct keyboard_priv *uc_priv = dev_get_uclass_priv(dev);
	struct stdio_dev *sdev = &uc_priv->sdev;
	struct input_config *input = &uc_priv->input;
	int ret;

	ret = cros_ec_keyb_decode_fdt(dev, priv);
	if (ret) {
		debug("%s: Cannot decode node (ret=%d)\n", __func__, ret);
		return -EINVAL;
	}
	input_set_delays(input, KBC_REPEAT_DELAY_MS, KBC_REPEAT_RATE_MS);
	ret = key_matrix_init(&priv->matrix, priv->key_rows, priv->key_cols,
			      priv->ghost_filter);
	if (ret) {
		debug("%s: cannot init key matrix\n", __func__);
		return ret;
	}
	ret = key_matrix_decode_fdt(dev, &priv->matrix);
	if (ret) {
		debug("%s: Could not decode key matrix from fdt\n", __func__);
		return ret;
	}
	debug("%s: Matrix keyboard %dx%d ready\n", __func__, priv->key_rows,
	      priv->key_cols);

	priv->input = input;
	input->dev = dev;
	input_add_tables(input, false);
	input->read_keys = cros_ec_kbc_check;
	strcpy(sdev->name, "cros-ec-keyb");

	/* Register the device. cros_ec_init_keyboard() will be called soon */
	return input_stdio_register(sdev);
}

static const struct keyboard_ops cros_ec_kbd_ops = {
};

static const struct udevice_id cros_ec_kbd_ids[] = {
	{ .compatible = "google,cros-ec-keyb" },
	{ }
};

U_BOOT_DRIVER(cros_ec_kbd) = {
	.name	= "cros_ec_kbd",
	.id	= UCLASS_KEYBOARD,
	.of_match = cros_ec_kbd_ids,
	.probe = cros_ec_kbd_probe,
	.ops	= &cros_ec_kbd_ops,
	.priv_auto_alloc_size = sizeof(struct cros_ec_keyb_priv),
};