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