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 DECLARE_GLOBAL_DATA_PTR; 19 20 enum { 21 KBC_MAX_KEYS = 8, /* Maximum keys held down at once */ 22 KBC_REPEAT_RATE_MS = 30, 23 KBC_REPEAT_DELAY_MS = 240, 24 }; 25 26 struct cros_ec_keyb_priv { 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 }; 33 34 35 /** 36 * Check the keyboard controller and return a list of key matrix positions 37 * for which a key is pressed 38 * 39 * @param dev Keyboard device 40 * @param keys List of keys that we have detected 41 * @param max_count Maximum number of keys to return 42 * @param samep Set to true if this scan repeats the last, else false 43 * @return number of pressed keys, 0 for none, -EIO on error 44 */ 45 static int check_for_keys(struct udevice *dev, struct key_matrix_key *keys, 46 int max_count, bool *samep) 47 { 48 struct cros_ec_keyb_priv *priv = dev_get_priv(dev); 49 struct key_matrix_key *key; 50 static struct mbkp_keyscan last_scan; 51 static bool last_scan_valid; 52 struct mbkp_keyscan scan; 53 unsigned int row, col, bit, data; 54 int num_keys; 55 56 if (cros_ec_scan_keyboard(dev->parent, &scan)) { 57 debug("%s: keyboard scan failed\n", __func__); 58 return -EIO; 59 } 60 *samep = last_scan_valid && !memcmp(&last_scan, &scan, sizeof(scan)); 61 62 /* 63 * This is a bit odd. The EC has no way to tell us that it has run 64 * out of key scans. It just returns the same scan over and over 65 * again. So the only way to detect that we have run out is to detect 66 * that this scan is the same as the last. 67 */ 68 last_scan_valid = true; 69 memcpy(&last_scan, &scan, sizeof(last_scan)); 70 71 for (col = num_keys = bit = 0; col < priv->matrix.num_cols; 72 col++) { 73 for (row = 0; row < priv->matrix.num_rows; row++) { 74 unsigned int mask = 1 << (bit & 7); 75 76 data = scan.data[bit / 8]; 77 if ((data & mask) && num_keys < max_count) { 78 key = keys + num_keys++; 79 key->row = row; 80 key->col = col; 81 key->valid = 1; 82 } 83 bit++; 84 } 85 } 86 87 return num_keys; 88 } 89 90 /** 91 * Check the keyboard, and send any keys that are pressed. 92 * 93 * This is called by input_tstc() and input_getc() when they need more 94 * characters 95 * 96 * @param input Input configuration 97 * @return 1, to indicate that we have something to look at 98 */ 99 int cros_ec_kbc_check(struct input_config *input) 100 { 101 struct udevice *dev = input->dev; 102 struct cros_ec_keyb_priv *priv = dev_get_priv(dev); 103 static struct key_matrix_key last_keys[KBC_MAX_KEYS]; 104 static int last_num_keys; 105 struct key_matrix_key keys[KBC_MAX_KEYS]; 106 int keycodes[KBC_MAX_KEYS]; 107 int num_keys, num_keycodes; 108 int irq_pending, sent; 109 bool same = false; 110 111 /* 112 * Loop until the EC has no more keyscan records, or we have 113 * received at least one character. This means we know that tstc() 114 * will always return non-zero if keys have been pressed. 115 * 116 * Without this loop, a key release (which generates no new ascii 117 * characters) will cause us to exit this function, and just tstc() 118 * may return 0 before all keys have been read from the EC. 119 */ 120 do { 121 irq_pending = cros_ec_interrupt_pending(dev->parent); 122 if (irq_pending) { 123 num_keys = check_for_keys(dev, keys, KBC_MAX_KEYS, 124 &same); 125 if (num_keys < 0) 126 return 0; 127 last_num_keys = num_keys; 128 memcpy(last_keys, keys, sizeof(keys)); 129 } else { 130 /* 131 * EC doesn't want to be asked, so use keys from last 132 * time. 133 */ 134 num_keys = last_num_keys; 135 memcpy(keys, last_keys, sizeof(keys)); 136 } 137 138 if (num_keys < 0) 139 return -1; 140 num_keycodes = key_matrix_decode(&priv->matrix, keys, 141 num_keys, keycodes, KBC_MAX_KEYS); 142 sent = input_send_keycodes(input, keycodes, num_keycodes); 143 144 /* 145 * For those ECs without an interrupt, stop scanning when we 146 * see that the scan is the same as last time. 147 */ 148 if ((irq_pending < 0) && same) 149 break; 150 } while (irq_pending && !sent); 151 152 return 1; 153 } 154 155 /** 156 * Decode MBKP keyboard details from the device tree 157 * 158 * @param blob Device tree blob 159 * @param node Node to decode from 160 * @param config Configuration data read from fdt 161 * @return 0 if ok, -1 on error 162 */ 163 static int cros_ec_keyb_decode_fdt(struct udevice *dev, 164 struct cros_ec_keyb_priv *config) 165 { 166 /* 167 * Get keyboard rows and columns - at present we are limited to 168 * 8 columns by the protocol (one byte per row scan) 169 */ 170 config->key_rows = dev_read_u32_default(dev, "keypad,num-rows", 0); 171 config->key_cols = dev_read_u32_default(dev, "keypad,num-columns", 0); 172 if (!config->key_rows || !config->key_cols || 173 config->key_rows * config->key_cols / 8 174 > CROS_EC_KEYSCAN_COLS) { 175 debug("%s: Invalid key matrix size %d x %d\n", __func__, 176 config->key_rows, config->key_cols); 177 return -1; 178 } 179 config->ghost_filter = dev_read_bool(dev, "google,needs-ghost-filter"); 180 181 return 0; 182 } 183 184 static int cros_ec_kbd_probe(struct udevice *dev) 185 { 186 struct cros_ec_keyb_priv *priv = dev_get_priv(dev); 187 struct keyboard_priv *uc_priv = dev_get_uclass_priv(dev); 188 struct stdio_dev *sdev = &uc_priv->sdev; 189 struct input_config *input = &uc_priv->input; 190 int ret; 191 192 ret = cros_ec_keyb_decode_fdt(dev, priv); 193 if (ret) { 194 debug("%s: Cannot decode node (ret=%d)\n", __func__, ret); 195 return -EINVAL; 196 } 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(dev, &priv->matrix); 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