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 67 /* 68 * After init we must wait a short time before polling the keyboard. 69 * This gives the tegra keyboard controller time to react after reset 70 * and lets us grab keys pressed during reset. 71 */ 72 unsigned int init_dly_ms; /* Delay before we can read keyboard */ 73 unsigned int start_time_ms; /* Time that we inited (in ms) */ 74 unsigned int last_poll_ms; /* Time we should last polled */ 75 unsigned int next_repeat_ms; /* Next time we repeat a key */ 76 } config; 77 78 /** 79 * reads the keyboard fifo for current keypresses 80 * 81 * @param config Keyboard config 82 * @param fifo Place to put fifo results 83 * @param max_keycodes Maximum number of key codes to put in the fifo 84 * @return number of items put into fifo 85 */ 86 static int tegra_kbc_find_keys(struct keyb *config, int *fifo, 87 int max_keycodes) 88 { 89 struct key_matrix_key keys[KBC_MAX_KPENT], *key; 90 u32 kp_ent = 0; 91 int i; 92 93 for (key = keys, i = 0; i < KBC_MAX_KPENT; i++, key++) { 94 /* Get next word */ 95 if (!(i & 3)) 96 kp_ent = readl(&config->kbc->kp_ent[i / 4]); 97 98 key->valid = (kp_ent & KBC_KPENT_VALID) != 0; 99 key->row = (kp_ent >> 3) & 0xf; 100 key->col = kp_ent & 0x7; 101 102 /* Shift to get next entry */ 103 kp_ent >>= 8; 104 } 105 return key_matrix_decode(&config->matrix, keys, KBC_MAX_KPENT, fifo, 106 max_keycodes); 107 } 108 109 /** 110 * Process all the keypress sequences in fifo and send key codes 111 * 112 * The fifo contains zero or more keypress sets. Each set 113 * consists of from 1-8 keycodes, representing the keycodes which 114 * were simultaneously pressed during that scan. 115 * 116 * This function works through each set and generates ASCII characters 117 * for each. Not that one set may produce more than one ASCII characters - 118 * for example holding down 'd' and 'f' at the same time will generate 119 * two ASCII characters. 120 * 121 * Note: if fifo_cnt is 0, we will tell the input layer that no keys are 122 * pressed. 123 * 124 * @param config Keyboard config 125 * @param fifo_cnt Number of entries in the keyboard fifo 126 */ 127 static void process_fifo(struct keyb *config, int fifo_cnt) 128 { 129 int fifo[KBC_MAX_KPENT]; 130 int cnt = 0; 131 132 /* Always call input_send_keycodes() at least once */ 133 do { 134 if (fifo_cnt) 135 cnt = tegra_kbc_find_keys(config, fifo, KBC_MAX_KPENT); 136 137 input_send_keycodes(&config->input, fifo, cnt); 138 } while (--fifo_cnt > 0); 139 } 140 141 /** 142 * Check the keyboard controller and emit ASCII characters for any keys that 143 * are pressed. 144 * 145 * @param config Keyboard config 146 */ 147 static void check_for_keys(struct keyb *config) 148 { 149 int fifo_cnt; 150 151 if (!config->first_scan && 152 get_timer(config->last_poll_ms) < KBC_REPEAT_RATE_MS) 153 return; 154 config->last_poll_ms = get_timer(0); 155 config->first_scan = 0; 156 157 /* 158 * Once we get here we know the keyboard has been scanned. So if there 159 * scan waiting for us, we know that nothing is held down. 160 */ 161 fifo_cnt = (readl(&config->kbc->interrupt) >> 4) & 0xf; 162 process_fifo(config, fifo_cnt); 163 } 164 165 /** 166 * In order to detect keys pressed on boot, wait for the hardware to 167 * complete scanning the keys. This includes time to transition from 168 * Wkup mode to Continous polling mode and the repoll time. We can 169 * deduct the time that's already elapsed. 170 * 171 * @param config Keyboard config 172 */ 173 static void kbd_wait_for_fifo_init(struct keyb *config) 174 { 175 if (!config->inited) { 176 unsigned long elapsed_time; 177 long delay_ms; 178 179 elapsed_time = get_timer(config->start_time_ms); 180 delay_ms = config->init_dly_ms - elapsed_time; 181 if (delay_ms > 0) { 182 udelay(delay_ms * 1000); 183 debug("%s: delay %ldms\n", __func__, delay_ms); 184 } 185 186 config->inited = 1; 187 } 188 } 189 190 /** 191 * Check the tegra keyboard, and send any keys that are pressed. 192 * 193 * This is called by input_tstc() and input_getc() when they need more 194 * characters 195 * 196 * @param input Input configuration 197 * @return 1, to indicate that we have something to look at 198 */ 199 int tegra_kbc_check(struct input_config *input) 200 { 201 kbd_wait_for_fifo_init(&config); 202 check_for_keys(&config); 203 204 return 1; 205 } 206 207 /** 208 * Test if keys are available to be read 209 * 210 * @return 0 if no keys available, 1 if keys are available 211 */ 212 static int kbd_tstc(void) 213 { 214 /* Just get input to do this for us */ 215 return input_tstc(&config.input); 216 } 217 218 /** 219 * Read a key 220 * 221 * TODO: U-Boot wants 0 for no key, but Ctrl-@ is a valid key... 222 * 223 * @return ASCII key code, or 0 if no key, or -1 if error 224 */ 225 static int kbd_getc(void) 226 { 227 /* Just get input to do this for us */ 228 return input_getc(&config.input); 229 } 230 231 /* configures keyboard GPIO registers to use the rows and columns */ 232 static void config_kbc_gpio(struct kbc_tegra *kbc) 233 { 234 int i; 235 236 for (i = 0; i < KBC_MAX_GPIO; i++) { 237 u32 row_cfg, col_cfg; 238 u32 r_shift = 5 * (i % 6); 239 u32 c_shift = 4 * (i % 8); 240 u32 r_mask = 0x1f << r_shift; 241 u32 c_mask = 0xf << c_shift; 242 u32 r_offs = i / 6; 243 u32 c_offs = i / 8; 244 245 row_cfg = readl(&kbc->row_cfg[r_offs]); 246 col_cfg = readl(&kbc->col_cfg[c_offs]); 247 248 row_cfg &= ~r_mask; 249 col_cfg &= ~c_mask; 250 251 if (i < config.matrix.num_rows) { 252 row_cfg |= ((i << 1) | 1) << r_shift; 253 } else { 254 col_cfg |= (((i - config.matrix.num_rows) << 1) | 1) 255 << c_shift; 256 } 257 258 writel(row_cfg, &kbc->row_cfg[r_offs]); 259 writel(col_cfg, &kbc->col_cfg[c_offs]); 260 } 261 } 262 263 /** 264 * Start up the keyboard device 265 */ 266 static void tegra_kbc_open(void) 267 { 268 struct kbc_tegra *kbc = config.kbc; 269 unsigned int scan_period; 270 u32 val; 271 272 /* 273 * We will scan at twice the keyboard repeat rate, so that there is 274 * always a scan ready when we check it in check_for_keys(). 275 */ 276 scan_period = KBC_REPEAT_RATE_MS / 2; 277 writel(scan_period * KBC_CLOCK_KHZ, &kbc->rpt_dly); 278 writel(scan_period * KBC_CLOCK_KHZ, &kbc->init_dly); 279 /* 280 * Before reading from the keyboard we must wait for the init_dly 281 * plus the rpt_delay, plus 2ms for the row scan time. 282 */ 283 config.init_dly_ms = scan_period * 2 + 2; 284 285 val = KBC_DEBOUNCE_COUNT << KBC_DEBOUNCE_CNT_SHIFT; 286 val |= 1 << KBC_FIFO_TH_CNT_SHIFT; /* fifo interrupt threshold */ 287 val |= KBC_CONTROL_KBC_EN; /* enable */ 288 writel(val, &kbc->control); 289 290 config.start_time_ms = get_timer(0); 291 config.last_poll_ms = config.next_repeat_ms = get_timer(0); 292 config.first_scan = 1; 293 } 294 295 /** 296 * Set up the tegra keyboard. This is called by the stdio device handler 297 * 298 * We want to do this init when the keyboard is actually used rather than 299 * at start-up, since keyboard input may not currently be selected. 300 * 301 * Once the keyboard starts there will be a period during which we must 302 * wait for the keyboard to init. We do this only when a key is first 303 * read - see kbd_wait_for_fifo_init(). 304 * 305 * @return 0 if ok, -ve on error 306 */ 307 static int init_tegra_keyboard(void) 308 { 309 #ifdef CONFIG_OF_CONTROL 310 int node; 311 312 node = fdtdec_next_compatible(gd->fdt_blob, 0, 313 COMPAT_NVIDIA_TEGRA20_KBC); 314 if (node < 0) { 315 debug("%s: cannot locate keyboard node\n", __func__); 316 return node; 317 } 318 config.kbc = (struct kbc_tegra *)fdtdec_get_addr(gd->fdt_blob, 319 node, "reg"); 320 if ((fdt_addr_t)config.kbc == FDT_ADDR_T_NONE) { 321 debug("%s: No keyboard register found\n", __func__); 322 return -1; 323 } 324 input_set_delays(&config.input, KBC_REPEAT_DELAY_MS, 325 KBC_REPEAT_RATE_MS); 326 327 /* Decode the keyboard matrix information (16 rows, 8 columns) */ 328 if (key_matrix_init(&config.matrix, 16, 8, 1)) { 329 debug("%s: Could not init key matrix\n", __func__); 330 return -1; 331 } 332 if (key_matrix_decode_fdt(&config.matrix, gd->fdt_blob, node)) { 333 debug("%s: Could not decode key matrix from fdt\n", __func__); 334 return -1; 335 } 336 if (config.matrix.fn_keycode) { 337 if (input_add_table(&config.input, KEY_FN, -1, 338 config.matrix.fn_keycode, 339 config.matrix.key_count)) 340 return -1; 341 } 342 #else 343 #error "Tegra keyboard driver requires FDT definitions" 344 #endif 345 346 /* Set up pin mux and enable the clock */ 347 funcmux_select(PERIPH_ID_KBC, FUNCMUX_DEFAULT); 348 clock_enable(PERIPH_ID_KBC); 349 config_kbc_gpio(config.kbc); 350 351 tegra_kbc_open(); 352 debug("%s: Tegra keyboard ready\n", __func__); 353 354 return 0; 355 } 356 357 int drv_keyboard_init(void) 358 { 359 struct stdio_dev dev; 360 361 if (input_init(&config.input, 0)) { 362 debug("%s: Cannot set up input\n", __func__); 363 return -1; 364 } 365 config.input.read_keys = tegra_kbc_check; 366 367 memset(&dev, '\0', sizeof(dev)); 368 strcpy(dev.name, "tegra-kbc"); 369 dev.flags = DEV_FLAGS_INPUT | DEV_FLAGS_SYSTEM; 370 dev.getc = kbd_getc; 371 dev.tstc = kbd_tstc; 372 dev.start = init_tegra_keyboard; 373 374 /* Register the device. init_tegra_keyboard() will be called soon */ 375 return input_stdio_register(&dev); 376 } 377