2 * Chromium OS Matrix Keyboard
4 * Copyright (c) 2012 The Chromium OS Authors.
6 * SPDX-License-Identifier: GPL-2.0+
16 #include <key_matrix.h>
17 #include <stdio_dev.h>
19 DECLARE_GLOBAL_DATA_PTR;
22 KBC_MAX_KEYS = 8, /* Maximum keys held down at once */
23 KBC_REPEAT_RATE_MS = 30,
24 KBC_REPEAT_DELAY_MS = 240,
27 struct cros_ec_keyb_priv {
28 struct input_config *input; /* The input layer */
29 struct key_matrix matrix; /* The key matrix layer */
30 int key_rows; /* Number of keyboard rows */
31 int key_cols; /* Number of keyboard columns */
32 int ghost_filter; /* 1 to enable ghost filter, else 0 */
37 * Check the keyboard controller and return a list of key matrix positions
38 * for which a key is pressed
40 * @param dev Keyboard device
41 * @param keys List of keys that we have detected
42 * @param max_count Maximum number of keys to return
43 * @param samep Set to true if this scan repeats the last, else false
44 * @return number of pressed keys, 0 for none, -EIO on error
46 static int check_for_keys(struct udevice *dev, struct key_matrix_key *keys,
47 int max_count, bool *samep)
49 struct cros_ec_keyb_priv *priv = dev_get_priv(dev);
50 struct key_matrix_key *key;
51 static struct mbkp_keyscan last_scan;
52 static bool last_scan_valid;
53 struct mbkp_keyscan scan;
54 unsigned int row, col, bit, data;
57 if (cros_ec_scan_keyboard(dev->parent, &scan)) {
58 debug("%s: keyboard scan failed\n", __func__);
61 *samep = last_scan_valid && !memcmp(&last_scan, &scan, sizeof(scan));
64 * This is a bit odd. The EC has no way to tell us that it has run
65 * out of key scans. It just returns the same scan over and over
66 * again. So the only way to detect that we have run out is to detect
67 * that this scan is the same as the last.
69 last_scan_valid = true;
70 memcpy(&last_scan, &scan, sizeof(last_scan));
72 for (col = num_keys = bit = 0; col < priv->matrix.num_cols;
74 for (row = 0; row < priv->matrix.num_rows; row++) {
75 unsigned int mask = 1 << (bit & 7);
77 data = scan.data[bit / 8];
78 if ((data & mask) && num_keys < max_count) {
79 key = keys + num_keys++;
92 * Check the keyboard, and send any keys that are pressed.
94 * This is called by input_tstc() and input_getc() when they need more
97 * @param input Input configuration
98 * @return 1, to indicate that we have something to look at
100 int cros_ec_kbc_check(struct input_config *input)
102 struct udevice *dev = input->dev;
103 struct cros_ec_keyb_priv *priv = dev_get_priv(dev);
104 static struct key_matrix_key last_keys[KBC_MAX_KEYS];
105 static int last_num_keys;
106 struct key_matrix_key keys[KBC_MAX_KEYS];
107 int keycodes[KBC_MAX_KEYS];
108 int num_keys, num_keycodes;
109 int irq_pending, sent;
113 * Loop until the EC has no more keyscan records, or we have
114 * received at least one character. This means we know that tstc()
115 * will always return non-zero if keys have been pressed.
117 * Without this loop, a key release (which generates no new ascii
118 * characters) will cause us to exit this function, and just tstc()
119 * may return 0 before all keys have been read from the EC.
122 irq_pending = cros_ec_interrupt_pending(dev->parent);
124 num_keys = check_for_keys(dev, keys, KBC_MAX_KEYS,
128 last_num_keys = num_keys;
129 memcpy(last_keys, keys, sizeof(keys));
132 * EC doesn't want to be asked, so use keys from last
135 num_keys = last_num_keys;
136 memcpy(keys, last_keys, sizeof(keys));
141 num_keycodes = key_matrix_decode(&priv->matrix, keys,
142 num_keys, keycodes, KBC_MAX_KEYS);
143 sent = input_send_keycodes(input, keycodes, num_keycodes);
146 * For those ECs without an interrupt, stop scanning when we
147 * see that the scan is the same as last time.
149 if ((irq_pending < 0) && same)
151 } while (irq_pending && !sent);
157 * Decode MBKP keyboard details from the device tree
159 * @param blob Device tree blob
160 * @param node Node to decode from
161 * @param config Configuration data read from fdt
162 * @return 0 if ok, -1 on error
164 static int cros_ec_keyb_decode_fdt(const void *blob, int node,
165 struct cros_ec_keyb_priv *config)
168 * Get keyboard rows and columns - at present we are limited to
169 * 8 columns by the protocol (one byte per row scan)
171 config->key_rows = fdtdec_get_int(blob, node, "keypad,num-rows", 0);
172 config->key_cols = fdtdec_get_int(blob, node, "keypad,num-columns", 0);
173 if (!config->key_rows || !config->key_cols ||
174 config->key_rows * config->key_cols / 8
175 > CROS_EC_KEYSCAN_COLS) {
176 debug("%s: Invalid key matrix size %d x %d\n", __func__,
177 config->key_rows, config->key_cols);
180 config->ghost_filter = fdtdec_get_bool(blob, node,
181 "google,needs-ghost-filter");
185 static int cros_ec_kbd_probe(struct udevice *dev)
187 struct cros_ec_keyb_priv *priv = dev_get_priv(dev);
188 struct keyboard_priv *uc_priv = dev_get_uclass_priv(dev);
189 struct stdio_dev *sdev = &uc_priv->sdev;
190 struct input_config *input = &uc_priv->input;
191 const void *blob = gd->fdt_blob;
192 int node = dev_of_offset(dev);
195 if (cros_ec_keyb_decode_fdt(blob, node, priv))
197 input_set_delays(input, KBC_REPEAT_DELAY_MS, KBC_REPEAT_RATE_MS);
198 ret = key_matrix_init(&priv->matrix, priv->key_rows, priv->key_cols,
201 debug("%s: cannot init key matrix\n", __func__);
204 ret = key_matrix_decode_fdt(&priv->matrix, gd->fdt_blob, node);
206 debug("%s: Could not decode key matrix from fdt\n", __func__);
209 debug("%s: Matrix keyboard %dx%d ready\n", __func__, priv->key_rows,
214 input_add_tables(input, false);
215 input->read_keys = cros_ec_kbc_check;
216 strcpy(sdev->name, "cros-ec-keyb");
218 /* Register the device. cros_ec_init_keyboard() will be called soon */
219 return input_stdio_register(sdev);
222 static const struct keyboard_ops cros_ec_kbd_ops = {
225 static const struct udevice_id cros_ec_kbd_ids[] = {
226 { .compatible = "google,cros-ec-keyb" },
230 U_BOOT_DRIVER(cros_ec_kbd) = {
231 .name = "cros_ec_kbd",
232 .id = UCLASS_KEYBOARD,
233 .of_match = cros_ec_kbd_ids,
234 .probe = cros_ec_kbd_probe,
235 .ops = &cros_ec_kbd_ops,
236 .priv_auto_alloc_size = sizeof(struct cros_ec_keyb_priv),