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 <input.h> 14 #include <keyboard.h> 15 #include <key_matrix.h> 16 #include <stdio_dev.h> 17 18 enum { 19 KBC_MAX_KEYS = 8, /* Maximum keys held down at once */ 20 KBC_REPEAT_RATE_MS = 30, 21 KBC_REPEAT_DELAY_MS = 240, 22 }; 23 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 */ 30 }; 31 32 33 /** 34 * Check the keyboard controller and return a list of key matrix positions 35 * for which a key is pressed 36 * 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 42 */ 43 static int check_for_keys(struct udevice *dev, struct key_matrix_key *keys, 44 int max_count, bool *samep) 45 { 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; 52 int num_keys; 53 54 if (cros_ec_scan_keyboard(dev->parent, &scan)) { 55 debug("%s: keyboard scan failed\n", __func__); 56 return -EIO; 57 } 58 *samep = last_scan_valid && !memcmp(&last_scan, &scan, sizeof(scan)); 59 60 /* 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. 65 */ 66 last_scan_valid = true; 67 memcpy(&last_scan, &scan, sizeof(last_scan)); 68 69 for (col = num_keys = bit = 0; col < priv->matrix.num_cols; 70 col++) { 71 for (row = 0; row < priv->matrix.num_rows; row++) { 72 unsigned int mask = 1 << (bit & 7); 73 74 data = scan.data[bit / 8]; 75 if ((data & mask) && num_keys < max_count) { 76 key = keys + num_keys++; 77 key->row = row; 78 key->col = col; 79 key->valid = 1; 80 } 81 bit++; 82 } 83 } 84 85 return num_keys; 86 } 87 88 /** 89 * Check the keyboard, and send any keys that are pressed. 90 * 91 * This is called by input_tstc() and input_getc() when they need more 92 * characters 93 * 94 * @param input Input configuration 95 * @return 1, to indicate that we have something to look at 96 */ 97 int cros_ec_kbc_check(struct input_config *input) 98 { 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; 107 bool same = false; 108 109 /* 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. 113 * 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. 117 */ 118 do { 119 irq_pending = cros_ec_interrupt_pending(dev->parent); 120 if (irq_pending) { 121 num_keys = check_for_keys(dev, keys, KBC_MAX_KEYS, 122 &same); 123 if (num_keys < 0) 124 return 0; 125 last_num_keys = num_keys; 126 memcpy(last_keys, keys, sizeof(keys)); 127 } else { 128 /* 129 * EC doesn't want to be asked, so use keys from last 130 * time. 131 */ 132 num_keys = last_num_keys; 133 memcpy(keys, last_keys, sizeof(keys)); 134 } 135 136 if (num_keys < 0) 137 return -1; 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); 141 142 /* 143 * For those ECs without an interrupt, stop scanning when we 144 * see that the scan is the same as last time. 145 */ 146 if ((irq_pending < 0) && same) 147 break; 148 } while (irq_pending && !sent); 149 150 return 1; 151 } 152 153 /** 154 * Decode MBKP keyboard details from the device tree 155 * 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 160 */ 161 static int cros_ec_keyb_decode_fdt(struct udevice *dev, 162 struct cros_ec_keyb_priv *config) 163 { 164 /* 165 * Get keyboard rows and columns - at present we are limited to 166 * 8 columns by the protocol (one byte per row scan) 167 */ 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); 175 return -1; 176 } 177 config->ghost_filter = dev_read_bool(dev, "google,needs-ghost-filter"); 178 179 return 0; 180 } 181 182 static int cros_ec_kbd_probe(struct udevice *dev) 183 { 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; 188 int ret; 189 190 ret = cros_ec_keyb_decode_fdt(dev, priv); 191 if (ret) { 192 debug("%s: Cannot decode node (ret=%d)\n", __func__, ret); 193 return -EINVAL; 194 } 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, 197 priv->ghost_filter); 198 if (ret) { 199 debug("%s: cannot init key matrix\n", __func__); 200 return ret; 201 } 202 ret = key_matrix_decode_fdt(dev, &priv->matrix); 203 if (ret) { 204 debug("%s: Could not decode key matrix from fdt\n", __func__); 205 return ret; 206 } 207 debug("%s: Matrix keyboard %dx%d ready\n", __func__, priv->key_rows, 208 priv->key_cols); 209 210 priv->input = input; 211 input->dev = dev; 212 input_add_tables(input, false); 213 input->read_keys = cros_ec_kbc_check; 214 strcpy(sdev->name, "cros-ec-keyb"); 215 216 /* Register the device. cros_ec_init_keyboard() will be called soon */ 217 return input_stdio_register(sdev); 218 } 219 220 static const struct keyboard_ops cros_ec_kbd_ops = { 221 }; 222 223 static const struct udevice_id cros_ec_kbd_ids[] = { 224 { .compatible = "google,cros-ec-keyb" }, 225 { } 226 }; 227 228 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), 235 }; 236