1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Chromium OS Matrix Keyboard
4 *
5 * Copyright (c) 2012 The Chromium OS Authors.
6 */
7
8 #include <cros_ec.h>
9 #include <dm.h>
10 #include <errno.h>
11 #include <input.h>
12 #include <keyboard.h>
13 #include <key_matrix.h>
14 #include <log.h>
15 #include <stdio_dev.h>
16
17 enum {
18 KBC_MAX_KEYS = 8, /* Maximum keys held down at once */
19 KBC_REPEAT_RATE_MS = 30,
20 KBC_REPEAT_DELAY_MS = 240,
21 };
22
23 struct cros_ec_keyb_priv {
24 struct input_config *input; /* The input layer */
25 struct key_matrix matrix; /* The key matrix layer */
26 int key_rows; /* Number of keyboard rows */
27 int key_cols; /* Number of keyboard columns */
28 int ghost_filter; /* 1 to enable ghost filter, else 0 */
29 };
30
31 /**
32 * Check the keyboard controller and return a list of key matrix positions
33 * for which a key is pressed
34 *
35 * @param dev Keyboard device
36 * @param keys List of keys that we have detected
37 * @param max_count Maximum number of keys to return
38 * @param samep Set to true if this scan repeats the last, else false
39 * Return: number of pressed keys, 0 for none, -EIO on error
40 */
check_for_keys(struct udevice * dev,struct key_matrix_key * keys,int max_count,bool * samep)41 static int check_for_keys(struct udevice *dev, struct key_matrix_key *keys,
42 int max_count, bool *samep)
43 {
44 struct cros_ec_keyb_priv *priv = dev_get_priv(dev);
45 struct key_matrix_key *key;
46 static struct mbkp_keyscan last_scan;
47 static bool last_scan_valid;
48 struct ec_response_get_next_event event;
49 struct mbkp_keyscan *scan = (struct mbkp_keyscan *)
50 &event.data.key_matrix;
51 unsigned int row, col, bit, data;
52 int num_keys;
53 int ret;
54
55 /* Get pending MKBP event. It may not be a key matrix event. */
56 do {
57 ret = cros_ec_get_next_event(dev->parent, &event);
58 /* The EC has no events for us at this time. */
59 if (ret == -EC_RES_UNAVAILABLE)
60 return -EIO;
61 else if (ret)
62 break;
63 } while (event.event_type != EC_MKBP_EVENT_KEY_MATRIX);
64
65 /* Try the old command if the EC doesn't support the above. */
66 if (ret == -EC_RES_INVALID_COMMAND) {
67 if (cros_ec_scan_keyboard(dev->parent, scan)) {
68 debug("%s: keyboard scan failed\n", __func__);
69 return -EIO;
70 }
71 } else if (ret) {
72 debug("%s: Error getting next MKBP event. (%d)\n",
73 __func__, ret);
74 return -EIO;
75 }
76 *samep = last_scan_valid && !memcmp(&last_scan, scan, sizeof(*scan));
77
78 /*
79 * This is a bit odd. The EC has no way to tell us that it has run
80 * out of key scans. It just returns the same scan over and over
81 * again. So the only way to detect that we have run out is to detect
82 * that this scan is the same as the last.
83 */
84 last_scan_valid = true;
85 memcpy(&last_scan, scan, sizeof(last_scan));
86
87 for (col = num_keys = bit = 0; col < priv->matrix.num_cols;
88 col++) {
89 for (row = 0; row < priv->matrix.num_rows; row++) {
90 unsigned int mask = 1 << (bit & 7);
91
92 data = scan->data[bit / 8];
93 if ((data & mask) && num_keys < max_count) {
94 key = keys + num_keys++;
95 key->row = row;
96 key->col = col;
97 key->valid = 1;
98 }
99 bit++;
100 }
101 }
102
103 return num_keys;
104 }
105
106 /**
107 * Check the keyboard, and send any keys that are pressed.
108 *
109 * This is called by input_tstc() and input_getc() when they need more
110 * characters
111 *
112 * @param input Input configuration
113 * Return: 1, to indicate that we have something to look at
114 */
cros_ec_kbc_check(struct input_config * input)115 int cros_ec_kbc_check(struct input_config *input)
116 {
117 struct udevice *dev = input->dev;
118 struct cros_ec_keyb_priv *priv = dev_get_priv(dev);
119 static struct key_matrix_key last_keys[KBC_MAX_KEYS];
120 static int last_num_keys;
121 struct key_matrix_key keys[KBC_MAX_KEYS];
122 int keycodes[KBC_MAX_KEYS];
123 int num_keys, num_keycodes;
124 int irq_pending, sent;
125 bool same = false;
126
127 /*
128 * Loop until the EC has no more keyscan records, or we have
129 * received at least one character. This means we know that tstc()
130 * will always return non-zero if keys have been pressed.
131 *
132 * Without this loop, a key release (which generates no new ascii
133 * characters) will cause us to exit this function, and just tstc()
134 * may return 0 before all keys have been read from the EC.
135 */
136 do {
137 irq_pending = cros_ec_interrupt_pending(dev->parent);
138 if (irq_pending) {
139 num_keys = check_for_keys(dev, keys, KBC_MAX_KEYS,
140 &same);
141 if (num_keys < 0)
142 return 0;
143 last_num_keys = num_keys;
144 memcpy(last_keys, keys, sizeof(keys));
145 } else {
146 /*
147 * EC doesn't want to be asked, so use keys from last
148 * time.
149 */
150 num_keys = last_num_keys;
151 memcpy(keys, last_keys, sizeof(keys));
152 }
153
154 if (num_keys < 0)
155 return -1;
156 num_keycodes = key_matrix_decode(&priv->matrix, keys,
157 num_keys, keycodes, KBC_MAX_KEYS);
158 sent = input_send_keycodes(input, keycodes, num_keycodes);
159
160 /*
161 * For those ECs without an interrupt, stop scanning when we
162 * see that the scan is the same as last time.
163 */
164 if ((irq_pending < 0) && same)
165 break;
166 } while (irq_pending && !sent);
167
168 return 1;
169 }
170
171 /**
172 * Decode MBKP keyboard details from the device tree
173 *
174 * @param blob Device tree blob
175 * @param node Node to decode from
176 * @param config Configuration data read from fdt
177 * Return: 0 if ok, -1 on error
178 */
cros_ec_keyb_decode_fdt(struct udevice * dev,struct cros_ec_keyb_priv * config)179 static int cros_ec_keyb_decode_fdt(struct udevice *dev,
180 struct cros_ec_keyb_priv *config)
181 {
182 /*
183 * Get keyboard rows and columns - at present we are limited to
184 * 8 columns by the protocol (one byte per row scan)
185 */
186 config->key_rows = dev_read_u32_default(dev, "keypad,num-rows", 0);
187 config->key_cols = dev_read_u32_default(dev, "keypad,num-columns", 0);
188 if (!config->key_rows || !config->key_cols ||
189 config->key_rows * config->key_cols / 8
190 > CROS_EC_KEYSCAN_COLS) {
191 debug("%s: Invalid key matrix size %d x %d\n", __func__,
192 config->key_rows, config->key_cols);
193 return -1;
194 }
195 config->ghost_filter = dev_read_bool(dev, "google,needs-ghost-filter");
196
197 return 0;
198 }
199
cros_ec_kbd_probe(struct udevice * dev)200 static int cros_ec_kbd_probe(struct udevice *dev)
201 {
202 struct cros_ec_keyb_priv *priv = dev_get_priv(dev);
203 struct keyboard_priv *uc_priv = dev_get_uclass_priv(dev);
204 struct stdio_dev *sdev = &uc_priv->sdev;
205 struct input_config *input = &uc_priv->input;
206 int ret;
207
208 ret = cros_ec_keyb_decode_fdt(dev, priv);
209 if (ret) {
210 debug("%s: Cannot decode node (ret=%d)\n", __func__, ret);
211 return -EINVAL;
212 }
213 input_set_delays(input, KBC_REPEAT_DELAY_MS, KBC_REPEAT_RATE_MS);
214 ret = key_matrix_init(&priv->matrix, priv->key_rows, priv->key_cols,
215 priv->ghost_filter);
216 if (ret) {
217 debug("%s: cannot init key matrix\n", __func__);
218 return ret;
219 }
220 ret = key_matrix_decode_fdt(dev, &priv->matrix);
221 if (ret) {
222 debug("%s: Could not decode key matrix from fdt\n", __func__);
223 return ret;
224 }
225 debug("%s: Matrix keyboard %dx%d ready\n", __func__, priv->key_rows,
226 priv->key_cols);
227
228 priv->input = input;
229 input->dev = dev;
230 input_add_tables(input, false);
231 input->read_keys = cros_ec_kbc_check;
232 strcpy(sdev->name, "cros-ec-keyb");
233
234 /* Register the device. cros_ec_init_keyboard() will be called soon */
235 return input_stdio_register(sdev);
236 }
237
238 static const struct keyboard_ops cros_ec_kbd_ops = {
239 };
240
241 static const struct udevice_id cros_ec_kbd_ids[] = {
242 { .compatible = "google,cros-ec-keyb" },
243 { }
244 };
245
246 U_BOOT_DRIVER(google_cros_ec_keyb) = {
247 .name = "google_cros_ec_keyb",
248 .id = UCLASS_KEYBOARD,
249 .of_match = cros_ec_kbd_ids,
250 .probe = cros_ec_kbd_probe,
251 .ops = &cros_ec_kbd_ops,
252 .priv_auto = sizeof(struct cros_ec_keyb_priv),
253 };
254