2 * Chromium OS Matrix Keyboard
4 * Copyright (c) 2012 The Chromium OS Authors.
6 * SPDX-License-Identifier: GPL-2.0+
15 #include <key_matrix.h>
16 #include <stdio_dev.h>
19 KBC_MAX_KEYS = 8, /* Maximum keys held down at once */
20 KBC_REPEAT_RATE_MS = 30,
21 KBC_REPEAT_DELAY_MS = 240,
24 struct cros_ec_keyb_priv {
25 struct input_config *input; /* The input layer */
26 struct key_matrix matrix; /* The key matrix layer */
27 int key_rows; /* Number of keyboard rows */
28 int key_cols; /* Number of keyboard columns */
29 int ghost_filter; /* 1 to enable ghost filter, else 0 */
34 * Check the keyboard controller and return a list of key matrix positions
35 * for which a key is pressed
37 * @param dev Keyboard device
38 * @param keys List of keys that we have detected
39 * @param max_count Maximum number of keys to return
40 * @param samep Set to true if this scan repeats the last, else false
41 * @return number of pressed keys, 0 for none, -EIO on error
43 static int check_for_keys(struct udevice *dev, struct key_matrix_key *keys,
44 int max_count, bool *samep)
46 struct cros_ec_keyb_priv *priv = dev_get_priv(dev);
47 struct key_matrix_key *key;
48 static struct mbkp_keyscan last_scan;
49 static bool last_scan_valid;
50 struct mbkp_keyscan scan;
51 unsigned int row, col, bit, data;
54 if (cros_ec_scan_keyboard(dev->parent, &scan)) {
55 debug("%s: keyboard scan failed\n", __func__);
58 *samep = last_scan_valid && !memcmp(&last_scan, &scan, sizeof(scan));
61 * This is a bit odd. The EC has no way to tell us that it has run
62 * out of key scans. It just returns the same scan over and over
63 * again. So the only way to detect that we have run out is to detect
64 * that this scan is the same as the last.
66 last_scan_valid = true;
67 memcpy(&last_scan, &scan, sizeof(last_scan));
69 for (col = num_keys = bit = 0; col < priv->matrix.num_cols;
71 for (row = 0; row < priv->matrix.num_rows; row++) {
72 unsigned int mask = 1 << (bit & 7);
74 data = scan.data[bit / 8];
75 if ((data & mask) && num_keys < max_count) {
76 key = keys + num_keys++;
89 * Check the keyboard, and send any keys that are pressed.
91 * This is called by input_tstc() and input_getc() when they need more
94 * @param input Input configuration
95 * @return 1, to indicate that we have something to look at
97 int cros_ec_kbc_check(struct input_config *input)
99 struct udevice *dev = input->dev;
100 struct cros_ec_keyb_priv *priv = dev_get_priv(dev);
101 static struct key_matrix_key last_keys[KBC_MAX_KEYS];
102 static int last_num_keys;
103 struct key_matrix_key keys[KBC_MAX_KEYS];
104 int keycodes[KBC_MAX_KEYS];
105 int num_keys, num_keycodes;
106 int irq_pending, sent;
110 * Loop until the EC has no more keyscan records, or we have
111 * received at least one character. This means we know that tstc()
112 * will always return non-zero if keys have been pressed.
114 * Without this loop, a key release (which generates no new ascii
115 * characters) will cause us to exit this function, and just tstc()
116 * may return 0 before all keys have been read from the EC.
119 irq_pending = cros_ec_interrupt_pending(dev->parent);
121 num_keys = check_for_keys(dev, keys, KBC_MAX_KEYS,
125 last_num_keys = num_keys;
126 memcpy(last_keys, keys, sizeof(keys));
129 * EC doesn't want to be asked, so use keys from last
132 num_keys = last_num_keys;
133 memcpy(keys, last_keys, sizeof(keys));
138 num_keycodes = key_matrix_decode(&priv->matrix, keys,
139 num_keys, keycodes, KBC_MAX_KEYS);
140 sent = input_send_keycodes(input, keycodes, num_keycodes);
143 * For those ECs without an interrupt, stop scanning when we
144 * see that the scan is the same as last time.
146 if ((irq_pending < 0) && same)
148 } while (irq_pending && !sent);
154 * Decode MBKP keyboard details from the device tree
156 * @param blob Device tree blob
157 * @param node Node to decode from
158 * @param config Configuration data read from fdt
159 * @return 0 if ok, -1 on error
161 static int cros_ec_keyb_decode_fdt(struct udevice *dev,
162 struct cros_ec_keyb_priv *config)
165 * Get keyboard rows and columns - at present we are limited to
166 * 8 columns by the protocol (one byte per row scan)
168 config->key_rows = dev_read_u32_default(dev, "keypad,num-rows", 0);
169 config->key_cols = dev_read_u32_default(dev, "keypad,num-columns", 0);
170 if (!config->key_rows || !config->key_cols ||
171 config->key_rows * config->key_cols / 8
172 > CROS_EC_KEYSCAN_COLS) {
173 debug("%s: Invalid key matrix size %d x %d\n", __func__,
174 config->key_rows, config->key_cols);
177 config->ghost_filter = dev_read_bool(dev, "google,needs-ghost-filter");
182 static int cros_ec_kbd_probe(struct udevice *dev)
184 struct cros_ec_keyb_priv *priv = dev_get_priv(dev);
185 struct keyboard_priv *uc_priv = dev_get_uclass_priv(dev);
186 struct stdio_dev *sdev = &uc_priv->sdev;
187 struct input_config *input = &uc_priv->input;
190 ret = cros_ec_keyb_decode_fdt(dev, priv);
192 debug("%s: Cannot decode node (ret=%d)\n", __func__, ret);
195 input_set_delays(input, KBC_REPEAT_DELAY_MS, KBC_REPEAT_RATE_MS);
196 ret = key_matrix_init(&priv->matrix, priv->key_rows, priv->key_cols,
199 debug("%s: cannot init key matrix\n", __func__);
202 ret = key_matrix_decode_fdt(dev, &priv->matrix);
204 debug("%s: Could not decode key matrix from fdt\n", __func__);
207 debug("%s: Matrix keyboard %dx%d ready\n", __func__, priv->key_rows,
212 input_add_tables(input, false);
213 input->read_keys = cros_ec_kbc_check;
214 strcpy(sdev->name, "cros-ec-keyb");
216 /* Register the device. cros_ec_init_keyboard() will be called soon */
217 return input_stdio_register(sdev);
220 static const struct keyboard_ops cros_ec_kbd_ops = {
223 static const struct udevice_id cros_ec_kbd_ids[] = {
224 { .compatible = "google,cros-ec-keyb" },
228 U_BOOT_DRIVER(cros_ec_kbd) = {
229 .name = "cros_ec_kbd",
230 .id = UCLASS_KEYBOARD,
231 .of_match = cros_ec_kbd_ids,
232 .probe = cros_ec_kbd_probe,
233 .ops = &cros_ec_kbd_ops,
234 .priv_auto_alloc_size = sizeof(struct cros_ec_keyb_priv),