1 /* 2 * Chromium OS Matrix Keyboard 3 * 4 * Copyright (c) 2012 The Chromium OS Authors. 5 * 6 * SPDX-License-Identifier: GPL-2.0+ 7 */ 8 9 #include <common.h> 10 #include <cros_ec.h> 11 #include <errno.h> 12 #include <fdtdec.h> 13 #include <input.h> 14 #include <key_matrix.h> 15 #include <stdio_dev.h> 16 17 DECLARE_GLOBAL_DATA_PTR; 18 19 enum { 20 KBC_MAX_KEYS = 8, /* Maximum keys held down at once */ 21 KBC_REPEAT_RATE_MS = 30, 22 KBC_REPEAT_DELAY_MS = 240, 23 }; 24 25 static struct keyb { 26 struct cros_ec_dev *dev; /* The CROS_EC device */ 27 struct input_config input; /* The input layer */ 28 struct key_matrix matrix; /* The key matrix layer */ 29 int key_rows; /* Number of keyboard rows */ 30 int key_cols; /* Number of keyboard columns */ 31 int ghost_filter; /* 1 to enable ghost filter, else 0 */ 32 int inited; /* 1 if keyboard is ready */ 33 } config; 34 35 36 /** 37 * Check the keyboard controller and return a list of key matrix positions 38 * for which a key is pressed 39 * 40 * @param config Keyboard config 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 45 */ 46 static int check_for_keys(struct keyb *config, 47 struct key_matrix_key *keys, int max_count, 48 bool *samep) 49 { 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; 55 int num_keys; 56 57 if (cros_ec_scan_keyboard(config->dev, &scan)) { 58 debug("%s: keyboard scan failed\n", __func__); 59 return -EIO; 60 } 61 *samep = last_scan_valid && !memcmp(&last_scan, &scan, sizeof(scan)); 62 63 /* 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. 68 */ 69 last_scan_valid = true; 70 memcpy(&last_scan, &scan, sizeof(last_scan)); 71 72 for (col = num_keys = bit = 0; col < config->matrix.num_cols; 73 col++) { 74 for (row = 0; row < config->matrix.num_rows; row++) { 75 unsigned int mask = 1 << (bit & 7); 76 77 data = scan.data[bit / 8]; 78 if ((data & mask) && num_keys < max_count) { 79 key = keys + num_keys++; 80 key->row = row; 81 key->col = col; 82 key->valid = 1; 83 } 84 bit++; 85 } 86 } 87 88 return num_keys; 89 } 90 91 /** 92 * Test if keys are available to be read 93 * 94 * @return 0 if no keys available, 1 if keys are available 95 */ 96 static int kbd_tstc(struct stdio_dev *dev) 97 { 98 /* Just get input to do this for us */ 99 return config.inited ? input_tstc(&config.input) : 0; 100 } 101 102 /** 103 * Read a key 104 * 105 * @return ASCII key code, or 0 if no key, or -1 if error 106 */ 107 static int kbd_getc(struct stdio_dev *dev) 108 { 109 /* Just get input to do this for us */ 110 return config.inited ? input_getc(&config.input) : 0; 111 } 112 113 /** 114 * Check the keyboard, and send any keys that are pressed. 115 * 116 * This is called by input_tstc() and input_getc() when they need more 117 * characters 118 * 119 * @param input Input configuration 120 * @return 1, to indicate that we have something to look at 121 */ 122 int cros_ec_kbc_check(struct input_config *input) 123 { 124 static struct key_matrix_key last_keys[KBC_MAX_KEYS]; 125 static int last_num_keys; 126 struct key_matrix_key keys[KBC_MAX_KEYS]; 127 int keycodes[KBC_MAX_KEYS]; 128 int num_keys, num_keycodes; 129 int irq_pending, sent; 130 bool same = false; 131 132 /* 133 * Loop until the EC has no more keyscan records, or we have 134 * received at least one character. This means we know that tstc() 135 * will always return non-zero if keys have been pressed. 136 * 137 * Without this loop, a key release (which generates no new ascii 138 * characters) will cause us to exit this function, and just tstc() 139 * may return 0 before all keys have been read from the EC. 140 */ 141 do { 142 irq_pending = cros_ec_interrupt_pending(config.dev); 143 if (irq_pending) { 144 num_keys = check_for_keys(&config, keys, KBC_MAX_KEYS, 145 &same); 146 if (num_keys < 0) 147 return 0; 148 last_num_keys = num_keys; 149 memcpy(last_keys, keys, sizeof(keys)); 150 } else { 151 /* 152 * EC doesn't want to be asked, so use keys from last 153 * time. 154 */ 155 num_keys = last_num_keys; 156 memcpy(keys, last_keys, sizeof(keys)); 157 } 158 159 if (num_keys < 0) 160 return -1; 161 num_keycodes = key_matrix_decode(&config.matrix, keys, 162 num_keys, keycodes, KBC_MAX_KEYS); 163 sent = input_send_keycodes(input, keycodes, num_keycodes); 164 165 /* 166 * For those ECs without an interrupt, stop scanning when we 167 * see that the scan is the same as last time. 168 */ 169 if ((irq_pending < 0) && same) 170 break; 171 } while (irq_pending && !sent); 172 173 return 1; 174 } 175 176 /** 177 * Decode MBKP keyboard details from the device tree 178 * 179 * @param blob Device tree blob 180 * @param node Node to decode from 181 * @param config Configuration data read from fdt 182 * @return 0 if ok, -1 on error 183 */ 184 static int cros_ec_keyb_decode_fdt(const void *blob, int node, 185 struct keyb *config) 186 { 187 /* 188 * Get keyboard rows and columns - at present we are limited to 189 * 8 columns by the protocol (one byte per row scan) 190 */ 191 config->key_rows = fdtdec_get_int(blob, node, "keypad,num-rows", 0); 192 config->key_cols = fdtdec_get_int(blob, node, "keypad,num-columns", 0); 193 if (!config->key_rows || !config->key_cols || 194 config->key_rows * config->key_cols / 8 195 > CROS_EC_KEYSCAN_COLS) { 196 debug("%s: Invalid key matrix size %d x %d\n", __func__, 197 config->key_rows, config->key_cols); 198 return -1; 199 } 200 config->ghost_filter = fdtdec_get_bool(blob, node, 201 "google,needs-ghost-filter"); 202 return 0; 203 } 204 205 /** 206 * Set up the keyboard. This is called by the stdio device handler. 207 * 208 * We want to do this init when the keyboard is actually used rather than 209 * at start-up, since keyboard input may not currently be selected. 210 * 211 * @return 0 if ok, -1 on error 212 */ 213 static int cros_ec_init_keyboard(struct stdio_dev *dev) 214 { 215 const void *blob = gd->fdt_blob; 216 int node; 217 218 config.dev = board_get_cros_ec_dev(); 219 if (!config.dev) { 220 debug("%s: no cros_ec device: cannot init keyboard\n", 221 __func__); 222 return -1; 223 } 224 node = fdtdec_next_compatible(blob, 0, COMPAT_GOOGLE_CROS_EC_KEYB); 225 if (node < 0) { 226 debug("%s: Node not found\n", __func__); 227 return -1; 228 } 229 if (cros_ec_keyb_decode_fdt(blob, node, &config)) 230 return -1; 231 input_set_delays(&config.input, KBC_REPEAT_DELAY_MS, 232 KBC_REPEAT_RATE_MS); 233 if (key_matrix_init(&config.matrix, config.key_rows, 234 config.key_cols, config.ghost_filter)) { 235 debug("%s: cannot init key matrix\n", __func__); 236 return -1; 237 } 238 if (key_matrix_decode_fdt(&config.matrix, gd->fdt_blob, node)) { 239 debug("%s: Could not decode key matrix from fdt\n", __func__); 240 return -1; 241 } 242 config.inited = 1; 243 debug("%s: Matrix keyboard %dx%d ready\n", __func__, config.key_rows, 244 config.key_cols); 245 246 return 0; 247 } 248 249 int drv_keyboard_init(void) 250 { 251 struct stdio_dev dev; 252 253 if (input_init(&config.input, 0)) { 254 debug("%s: Cannot set up input\n", __func__); 255 return -1; 256 } 257 config.input.read_keys = cros_ec_kbc_check; 258 259 memset(&dev, '\0', sizeof(dev)); 260 strcpy(dev.name, "cros-ec-keyb"); 261 dev.flags = DEV_FLAGS_INPUT | DEV_FLAGS_SYSTEM; 262 dev.getc = kbd_getc; 263 dev.tstc = kbd_tstc; 264 dev.start = cros_ec_init_keyboard; 265 266 /* Register the device. cros_ec_init_keyboard() will be called soon */ 267 return input_stdio_register(&dev); 268 } 269