1 /* 2 * (C) Copyright 2011 3 * NVIDIA Corporation <www.nvidia.com> 4 * 5 * See file CREDITS for list of people who contributed to this 6 * project. 7 * 8 * This program is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU General Public License as 10 * published by the Free Software Foundation; either version 2 of 11 * the License, or (at your option) any later version. 12 * 13 * This program is distributed in the hope that it will be useful, 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 * GNU General Public License for more details. 17 * 18 * You should have received a copy of the GNU General Public License 19 * along with this program; if not, write to the Free Software 20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, 21 * MA 02111-1307 USA 22 */ 23 24 #include <common.h> 25 #include <fdtdec.h> 26 #include <input.h> 27 #include <key_matrix.h> 28 #include <stdio_dev.h> 29 #include <tegra-kbc.h> 30 #include <asm/io.h> 31 #include <asm/arch/clock.h> 32 #include <asm/arch/funcmux.h> 33 #include <asm/arch-tegra/timer.h> 34 #include <linux/input.h> 35 36 DECLARE_GLOBAL_DATA_PTR; 37 38 enum { 39 KBC_MAX_GPIO = 24, 40 KBC_MAX_KPENT = 8, /* size of keypress entry queue */ 41 }; 42 43 #define KBC_FIFO_TH_CNT_SHIFT 14 44 #define KBC_DEBOUNCE_CNT_SHIFT 4 45 #define KBC_CONTROL_FIFO_CNT_INT_EN (1 << 3) 46 #define KBC_CONTROL_KBC_EN (1 << 0) 47 #define KBC_INT_FIFO_CNT_INT_STATUS (1 << 2) 48 #define KBC_KPENT_VALID (1 << 7) 49 #define KBC_ST_STATUS (1 << 3) 50 51 enum { 52 KBC_DEBOUNCE_COUNT = 2, 53 KBC_REPEAT_RATE_MS = 30, 54 KBC_REPEAT_DELAY_MS = 240, 55 KBC_CLOCK_KHZ = 32, /* Keyboard uses a 32KHz clock */ 56 }; 57 58 /* keyboard controller config and state */ 59 static struct keyb { 60 struct input_config input; /* The input layer */ 61 struct key_matrix matrix; /* The key matrix layer */ 62 63 struct kbc_tegra *kbc; /* tegra keyboard controller */ 64 unsigned char inited; /* 1 if keyboard has been inited */ 65 unsigned char first_scan; /* 1 if this is our first key scan */ 66 unsigned char created; /* 1 if driver has been created */ 67 68 /* 69 * After init we must wait a short time before polling the keyboard. 70 * This gives the tegra keyboard controller time to react after reset 71 * and lets us grab keys pressed during reset. 72 */ 73 unsigned int init_dly_ms; /* Delay before we can read keyboard */ 74 unsigned int start_time_ms; /* Time that we inited (in ms) */ 75 unsigned int last_poll_ms; /* Time we should last polled */ 76 unsigned int next_repeat_ms; /* Next time we repeat a key */ 77 } config; 78 79 /** 80 * reads the keyboard fifo for current keypresses 81 * 82 * @param config Keyboard config 83 * @param fifo Place to put fifo results 84 * @param max_keycodes Maximum number of key codes to put in the fifo 85 * @return number of items put into fifo 86 */ 87 static int tegra_kbc_find_keys(struct keyb *config, int *fifo, 88 int max_keycodes) 89 { 90 struct key_matrix_key keys[KBC_MAX_KPENT], *key; 91 u32 kp_ent = 0; 92 int i; 93 94 for (key = keys, i = 0; i < KBC_MAX_KPENT; i++, key++) { 95 /* Get next word */ 96 if (!(i & 3)) 97 kp_ent = readl(&config->kbc->kp_ent[i / 4]); 98 99 key->valid = (kp_ent & KBC_KPENT_VALID) != 0; 100 key->row = (kp_ent >> 3) & 0xf; 101 key->col = kp_ent & 0x7; 102 103 /* Shift to get next entry */ 104 kp_ent >>= 8; 105 } 106 return key_matrix_decode(&config->matrix, keys, KBC_MAX_KPENT, fifo, 107 max_keycodes); 108 } 109 110 /** 111 * Process all the keypress sequences in fifo and send key codes 112 * 113 * The fifo contains zero or more keypress sets. Each set 114 * consists of from 1-8 keycodes, representing the keycodes which 115 * were simultaneously pressed during that scan. 116 * 117 * This function works through each set and generates ASCII characters 118 * for each. Not that one set may produce more than one ASCII characters - 119 * for example holding down 'd' and 'f' at the same time will generate 120 * two ASCII characters. 121 * 122 * Note: if fifo_cnt is 0, we will tell the input layer that no keys are 123 * pressed. 124 * 125 * @param config Keyboard config 126 * @param fifo_cnt Number of entries in the keyboard fifo 127 */ 128 static void process_fifo(struct keyb *config, int fifo_cnt) 129 { 130 int fifo[KBC_MAX_KPENT]; 131 int cnt = 0; 132 133 /* Always call input_send_keycodes() at least once */ 134 do { 135 if (fifo_cnt) 136 cnt = tegra_kbc_find_keys(config, fifo, KBC_MAX_KPENT); 137 138 input_send_keycodes(&config->input, fifo, cnt); 139 } while (--fifo_cnt > 0); 140 } 141 142 /** 143 * Check the keyboard controller and emit ASCII characters for any keys that 144 * are pressed. 145 * 146 * @param config Keyboard config 147 */ 148 static void check_for_keys(struct keyb *config) 149 { 150 int fifo_cnt; 151 152 if (!config->first_scan && 153 get_timer(config->last_poll_ms) < KBC_REPEAT_RATE_MS) 154 return; 155 config->last_poll_ms = get_timer(0); 156 config->first_scan = 0; 157 158 /* 159 * Once we get here we know the keyboard has been scanned. So if there 160 * scan waiting for us, we know that nothing is held down. 161 */ 162 fifo_cnt = (readl(&config->kbc->interrupt) >> 4) & 0xf; 163 process_fifo(config, fifo_cnt); 164 } 165 166 /** 167 * In order to detect keys pressed on boot, wait for the hardware to 168 * complete scanning the keys. This includes time to transition from 169 * Wkup mode to Continous polling mode and the repoll time. We can 170 * deduct the time that's already elapsed. 171 * 172 * @param config Keyboard config 173 */ 174 static void kbd_wait_for_fifo_init(struct keyb *config) 175 { 176 if (!config->inited) { 177 unsigned long elapsed_time; 178 long delay_ms; 179 180 elapsed_time = get_timer(config->start_time_ms); 181 delay_ms = config->init_dly_ms - elapsed_time; 182 if (delay_ms > 0) { 183 udelay(delay_ms * 1000); 184 debug("%s: delay %ldms\n", __func__, delay_ms); 185 } 186 187 config->inited = 1; 188 } 189 } 190 191 /** 192 * Check the tegra keyboard, and send any keys that are pressed. 193 * 194 * This is called by input_tstc() and input_getc() when they need more 195 * characters 196 * 197 * @param input Input configuration 198 * @return 1, to indicate that we have something to look at 199 */ 200 int tegra_kbc_check(struct input_config *input) 201 { 202 kbd_wait_for_fifo_init(&config); 203 check_for_keys(&config); 204 205 return 1; 206 } 207 208 /** 209 * Test if keys are available to be read 210 * 211 * @return 0 if no keys available, 1 if keys are available 212 */ 213 static int kbd_tstc(void) 214 { 215 /* Just get input to do this for us */ 216 return input_tstc(&config.input); 217 } 218 219 /** 220 * Read a key 221 * 222 * TODO: U-Boot wants 0 for no key, but Ctrl-@ is a valid key... 223 * 224 * @return ASCII key code, or 0 if no key, or -1 if error 225 */ 226 static int kbd_getc(void) 227 { 228 /* Just get input to do this for us */ 229 return input_getc(&config.input); 230 } 231 232 /* configures keyboard GPIO registers to use the rows and columns */ 233 static void config_kbc_gpio(struct kbc_tegra *kbc) 234 { 235 int i; 236 237 for (i = 0; i < KBC_MAX_GPIO; i++) { 238 u32 row_cfg, col_cfg; 239 u32 r_shift = 5 * (i % 6); 240 u32 c_shift = 4 * (i % 8); 241 u32 r_mask = 0x1f << r_shift; 242 u32 c_mask = 0xf << c_shift; 243 u32 r_offs = i / 6; 244 u32 c_offs = i / 8; 245 246 row_cfg = readl(&kbc->row_cfg[r_offs]); 247 col_cfg = readl(&kbc->col_cfg[c_offs]); 248 249 row_cfg &= ~r_mask; 250 col_cfg &= ~c_mask; 251 252 if (i < config.matrix.num_rows) { 253 row_cfg |= ((i << 1) | 1) << r_shift; 254 } else { 255 col_cfg |= (((i - config.matrix.num_rows) << 1) | 1) 256 << c_shift; 257 } 258 259 writel(row_cfg, &kbc->row_cfg[r_offs]); 260 writel(col_cfg, &kbc->col_cfg[c_offs]); 261 } 262 } 263 264 /** 265 * Start up the keyboard device 266 */ 267 static void tegra_kbc_open(void) 268 { 269 struct kbc_tegra *kbc = config.kbc; 270 unsigned int scan_period; 271 u32 val; 272 273 /* 274 * We will scan at twice the keyboard repeat rate, so that there is 275 * always a scan ready when we check it in check_for_keys(). 276 */ 277 scan_period = KBC_REPEAT_RATE_MS / 2; 278 writel(scan_period * KBC_CLOCK_KHZ, &kbc->rpt_dly); 279 writel(scan_period * KBC_CLOCK_KHZ, &kbc->init_dly); 280 /* 281 * Before reading from the keyboard we must wait for the init_dly 282 * plus the rpt_delay, plus 2ms for the row scan time. 283 */ 284 config.init_dly_ms = scan_period * 2 + 2; 285 286 val = KBC_DEBOUNCE_COUNT << KBC_DEBOUNCE_CNT_SHIFT; 287 val |= 1 << KBC_FIFO_TH_CNT_SHIFT; /* fifo interrupt threshold */ 288 val |= KBC_CONTROL_KBC_EN; /* enable */ 289 writel(val, &kbc->control); 290 291 config.start_time_ms = get_timer(0); 292 config.last_poll_ms = config.next_repeat_ms = get_timer(0); 293 config.first_scan = 1; 294 } 295 296 /** 297 * Set up the tegra keyboard. This is called by the stdio device handler 298 * 299 * We want to do this init when the keyboard is actually used rather than 300 * at start-up, since keyboard input may not currently be selected. 301 * 302 * Once the keyboard starts there will be a period during which we must 303 * wait for the keyboard to init. We do this only when a key is first 304 * read - see kbd_wait_for_fifo_init(). 305 * 306 * @return 0 if ok, -ve on error 307 */ 308 static int init_tegra_keyboard(void) 309 { 310 /* check if already created */ 311 if (config.created) 312 return 0; 313 314 #ifdef CONFIG_OF_CONTROL 315 int node; 316 317 node = fdtdec_next_compatible(gd->fdt_blob, 0, 318 COMPAT_NVIDIA_TEGRA20_KBC); 319 if (node < 0) { 320 debug("%s: cannot locate keyboard node\n", __func__); 321 return node; 322 } 323 config.kbc = (struct kbc_tegra *)fdtdec_get_addr(gd->fdt_blob, 324 node, "reg"); 325 if ((fdt_addr_t)config.kbc == FDT_ADDR_T_NONE) { 326 debug("%s: No keyboard register found\n", __func__); 327 return -1; 328 } 329 input_set_delays(&config.input, KBC_REPEAT_DELAY_MS, 330 KBC_REPEAT_RATE_MS); 331 332 /* Decode the keyboard matrix information (16 rows, 8 columns) */ 333 if (key_matrix_init(&config.matrix, 16, 8, 1)) { 334 debug("%s: Could not init key matrix\n", __func__); 335 return -1; 336 } 337 if (key_matrix_decode_fdt(&config.matrix, gd->fdt_blob, node)) { 338 debug("%s: Could not decode key matrix from fdt\n", __func__); 339 return -1; 340 } 341 if (config.matrix.fn_keycode) { 342 if (input_add_table(&config.input, KEY_FN, -1, 343 config.matrix.fn_keycode, 344 config.matrix.key_count)) 345 return -1; 346 } 347 #else 348 #error "Tegra keyboard driver requires FDT definitions" 349 #endif 350 351 /* Set up pin mux and enable the clock */ 352 funcmux_select(PERIPH_ID_KBC, FUNCMUX_DEFAULT); 353 clock_enable(PERIPH_ID_KBC); 354 config_kbc_gpio(config.kbc); 355 356 tegra_kbc_open(); 357 config.created = 1; 358 debug("%s: Tegra keyboard ready\n", __func__); 359 360 return 0; 361 } 362 363 int drv_keyboard_init(void) 364 { 365 struct stdio_dev dev; 366 char *stdinname = getenv("stdin"); 367 int error; 368 369 if (input_init(&config.input, 0)) { 370 debug("%s: Cannot set up input\n", __func__); 371 return -1; 372 } 373 config.input.read_keys = tegra_kbc_check; 374 375 memset(&dev, '\0', sizeof(dev)); 376 strcpy(dev.name, "tegra-kbc"); 377 dev.flags = DEV_FLAGS_INPUT | DEV_FLAGS_SYSTEM; 378 dev.getc = kbd_getc; 379 dev.tstc = kbd_tstc; 380 dev.start = init_tegra_keyboard; 381 382 /* Register the device. init_tegra_keyboard() will be called soon */ 383 error = input_stdio_register(&dev); 384 if (error) 385 return error; 386 #ifdef CONFIG_CONSOLE_MUX 387 error = iomux_doenv(stdin, stdinname); 388 if (error) 389 return error; 390 #endif 391 return 0; 392 } 393