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 <dm.h> 12 #include <errno.h> 13 #include <fdtdec.h> 14 #include <input.h> 15 #include <keyboard.h> 16 #include <key_matrix.h> 17 #include <stdio_dev.h> 18 19 DECLARE_GLOBAL_DATA_PTR; 20 21 enum { 22 KBC_MAX_KEYS = 8, /* Maximum keys held down at once */ 23 KBC_REPEAT_RATE_MS = 30, 24 KBC_REPEAT_DELAY_MS = 240, 25 }; 26 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 */ 33 }; 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 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 45 */ 46 static int check_for_keys(struct udevice *dev, struct key_matrix_key *keys, 47 int max_count, bool *samep) 48 { 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; 55 int num_keys; 56 57 if (cros_ec_scan_keyboard(dev->parent, &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 < priv->matrix.num_cols; 73 col++) { 74 for (row = 0; row < priv->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 * Check the keyboard, and send any keys that are pressed. 93 * 94 * This is called by input_tstc() and input_getc() when they need more 95 * characters 96 * 97 * @param input Input configuration 98 * @return 1, to indicate that we have something to look at 99 */ 100 int cros_ec_kbc_check(struct input_config *input) 101 { 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; 110 bool same = false; 111 112 /* 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. 116 * 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. 120 */ 121 do { 122 irq_pending = cros_ec_interrupt_pending(dev->parent); 123 if (irq_pending) { 124 num_keys = check_for_keys(dev, keys, KBC_MAX_KEYS, 125 &same); 126 if (num_keys < 0) 127 return 0; 128 last_num_keys = num_keys; 129 memcpy(last_keys, keys, sizeof(keys)); 130 } else { 131 /* 132 * EC doesn't want to be asked, so use keys from last 133 * time. 134 */ 135 num_keys = last_num_keys; 136 memcpy(keys, last_keys, sizeof(keys)); 137 } 138 139 if (num_keys < 0) 140 return -1; 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); 144 145 /* 146 * For those ECs without an interrupt, stop scanning when we 147 * see that the scan is the same as last time. 148 */ 149 if ((irq_pending < 0) && same) 150 break; 151 } while (irq_pending && !sent); 152 153 return 1; 154 } 155 156 /** 157 * Decode MBKP keyboard details from the device tree 158 * 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 163 */ 164 static int cros_ec_keyb_decode_fdt(const void *blob, int node, 165 struct cros_ec_keyb_priv *config) 166 { 167 /* 168 * Get keyboard rows and columns - at present we are limited to 169 * 8 columns by the protocol (one byte per row scan) 170 */ 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); 178 return -1; 179 } 180 config->ghost_filter = fdtdec_get_bool(blob, node, 181 "google,needs-ghost-filter"); 182 return 0; 183 } 184 185 static int cros_ec_kbd_probe(struct udevice *dev) 186 { 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; 193 int ret; 194 195 if (cros_ec_keyb_decode_fdt(blob, node, priv)) 196 return -1; 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, 199 priv->ghost_filter); 200 if (ret) { 201 debug("%s: cannot init key matrix\n", __func__); 202 return ret; 203 } 204 ret = key_matrix_decode_fdt(&priv->matrix, gd->fdt_blob, node); 205 if (ret) { 206 debug("%s: Could not decode key matrix from fdt\n", __func__); 207 return ret; 208 } 209 debug("%s: Matrix keyboard %dx%d ready\n", __func__, priv->key_rows, 210 priv->key_cols); 211 212 priv->input = input; 213 input->dev = dev; 214 input_add_tables(input, false); 215 input->read_keys = cros_ec_kbc_check; 216 strcpy(sdev->name, "cros-ec-keyb"); 217 218 /* Register the device. cros_ec_init_keyboard() will be called soon */ 219 return input_stdio_register(sdev); 220 } 221 222 static const struct keyboard_ops cros_ec_kbd_ops = { 223 }; 224 225 static const struct udevice_id cros_ec_kbd_ids[] = { 226 { .compatible = "google,cros-ec-keyb" }, 227 { } 228 }; 229 230 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), 237 }; 238