1 /* 2 * (C) Copyright 2011 3 * NVIDIA Corporation <www.nvidia.com> 4 * 5 * SPDX-License-Identifier: GPL-2.0+ 6 */ 7 8 #include <common.h> 9 #include <fdtdec.h> 10 #include <input.h> 11 #include <key_matrix.h> 12 #include <stdio_dev.h> 13 #include <tegra-kbc.h> 14 #include <asm/io.h> 15 #include <asm/arch/clock.h> 16 #include <asm/arch/funcmux.h> 17 #include <asm/arch-tegra/timer.h> 18 #include <linux/input.h> 19 20 DECLARE_GLOBAL_DATA_PTR; 21 22 enum { 23 KBC_MAX_GPIO = 24, 24 KBC_MAX_KPENT = 8, /* size of keypress entry queue */ 25 }; 26 27 #define KBC_FIFO_TH_CNT_SHIFT 14 28 #define KBC_DEBOUNCE_CNT_SHIFT 4 29 #define KBC_CONTROL_FIFO_CNT_INT_EN (1 << 3) 30 #define KBC_CONTROL_KBC_EN (1 << 0) 31 #define KBC_INT_FIFO_CNT_INT_STATUS (1 << 2) 32 #define KBC_KPENT_VALID (1 << 7) 33 #define KBC_ST_STATUS (1 << 3) 34 35 enum { 36 KBC_DEBOUNCE_COUNT = 2, 37 KBC_REPEAT_RATE_MS = 30, 38 KBC_REPEAT_DELAY_MS = 240, 39 KBC_CLOCK_KHZ = 32, /* Keyboard uses a 32KHz clock */ 40 }; 41 42 /* keyboard controller config and state */ 43 static struct keyb { 44 struct input_config input; /* The input layer */ 45 struct key_matrix matrix; /* The key matrix layer */ 46 47 struct kbc_tegra *kbc; /* tegra keyboard controller */ 48 unsigned char inited; /* 1 if keyboard has been inited */ 49 unsigned char first_scan; /* 1 if this is our first key scan */ 50 unsigned char created; /* 1 if driver has been created */ 51 52 /* 53 * After init we must wait a short time before polling the keyboard. 54 * This gives the tegra keyboard controller time to react after reset 55 * and lets us grab keys pressed during reset. 56 */ 57 unsigned int init_dly_ms; /* Delay before we can read keyboard */ 58 unsigned int start_time_ms; /* Time that we inited (in ms) */ 59 unsigned int last_poll_ms; /* Time we should last polled */ 60 unsigned int next_repeat_ms; /* Next time we repeat a key */ 61 } config; 62 63 /** 64 * reads the keyboard fifo for current keypresses 65 * 66 * @param config Keyboard config 67 * @param fifo Place to put fifo results 68 * @param max_keycodes Maximum number of key codes to put in the fifo 69 * @return number of items put into fifo 70 */ 71 static int tegra_kbc_find_keys(struct keyb *config, int *fifo, 72 int max_keycodes) 73 { 74 struct key_matrix_key keys[KBC_MAX_KPENT], *key; 75 u32 kp_ent = 0; 76 int i; 77 78 for (key = keys, i = 0; i < KBC_MAX_KPENT; i++, key++) { 79 /* Get next word */ 80 if (!(i & 3)) 81 kp_ent = readl(&config->kbc->kp_ent[i / 4]); 82 83 key->valid = (kp_ent & KBC_KPENT_VALID) != 0; 84 key->row = (kp_ent >> 3) & 0xf; 85 key->col = kp_ent & 0x7; 86 87 /* Shift to get next entry */ 88 kp_ent >>= 8; 89 } 90 return key_matrix_decode(&config->matrix, keys, KBC_MAX_KPENT, fifo, 91 max_keycodes); 92 } 93 94 /** 95 * Process all the keypress sequences in fifo and send key codes 96 * 97 * The fifo contains zero or more keypress sets. Each set 98 * consists of from 1-8 keycodes, representing the keycodes which 99 * were simultaneously pressed during that scan. 100 * 101 * This function works through each set and generates ASCII characters 102 * for each. Not that one set may produce more than one ASCII characters - 103 * for example holding down 'd' and 'f' at the same time will generate 104 * two ASCII characters. 105 * 106 * Note: if fifo_cnt is 0, we will tell the input layer that no keys are 107 * pressed. 108 * 109 * @param config Keyboard config 110 * @param fifo_cnt Number of entries in the keyboard fifo 111 */ 112 static void process_fifo(struct keyb *config, int fifo_cnt) 113 { 114 int fifo[KBC_MAX_KPENT]; 115 int cnt = 0; 116 117 /* Always call input_send_keycodes() at least once */ 118 do { 119 if (fifo_cnt) 120 cnt = tegra_kbc_find_keys(config, fifo, KBC_MAX_KPENT); 121 122 input_send_keycodes(&config->input, fifo, cnt); 123 } while (--fifo_cnt > 0); 124 } 125 126 /** 127 * Check the keyboard controller and emit ASCII characters for any keys that 128 * are pressed. 129 * 130 * @param config Keyboard config 131 */ 132 static void check_for_keys(struct keyb *config) 133 { 134 int fifo_cnt; 135 136 if (!config->first_scan && 137 get_timer(config->last_poll_ms) < KBC_REPEAT_RATE_MS) 138 return; 139 config->last_poll_ms = get_timer(0); 140 config->first_scan = 0; 141 142 /* 143 * Once we get here we know the keyboard has been scanned. So if there 144 * scan waiting for us, we know that nothing is held down. 145 */ 146 fifo_cnt = (readl(&config->kbc->interrupt) >> 4) & 0xf; 147 process_fifo(config, fifo_cnt); 148 } 149 150 /** 151 * In order to detect keys pressed on boot, wait for the hardware to 152 * complete scanning the keys. This includes time to transition from 153 * Wkup mode to Continous polling mode and the repoll time. We can 154 * deduct the time that's already elapsed. 155 * 156 * @param config Keyboard config 157 */ 158 static void kbd_wait_for_fifo_init(struct keyb *config) 159 { 160 if (!config->inited) { 161 unsigned long elapsed_time; 162 long delay_ms; 163 164 elapsed_time = get_timer(config->start_time_ms); 165 delay_ms = config->init_dly_ms - elapsed_time; 166 if (delay_ms > 0) { 167 udelay(delay_ms * 1000); 168 debug("%s: delay %ldms\n", __func__, delay_ms); 169 } 170 171 config->inited = 1; 172 } 173 } 174 175 /** 176 * Check the tegra keyboard, and send any keys that are pressed. 177 * 178 * This is called by input_tstc() and input_getc() when they need more 179 * characters 180 * 181 * @param input Input configuration 182 * @return 1, to indicate that we have something to look at 183 */ 184 static int tegra_kbc_check(struct input_config *input) 185 { 186 kbd_wait_for_fifo_init(&config); 187 check_for_keys(&config); 188 189 return 1; 190 } 191 192 /** 193 * Test if keys are available to be read 194 * 195 * @return 0 if no keys available, 1 if keys are available 196 */ 197 static int kbd_tstc(struct stdio_dev *dev) 198 { 199 /* Just get input to do this for us */ 200 return input_tstc(&config.input); 201 } 202 203 /** 204 * Read a key 205 * 206 * TODO: U-Boot wants 0 for no key, but Ctrl-@ is a valid key... 207 * 208 * @return ASCII key code, or 0 if no key, or -1 if error 209 */ 210 static int kbd_getc(struct stdio_dev *dev) 211 { 212 /* Just get input to do this for us */ 213 return input_getc(&config.input); 214 } 215 216 /* configures keyboard GPIO registers to use the rows and columns */ 217 static void config_kbc_gpio(struct kbc_tegra *kbc) 218 { 219 int i; 220 221 for (i = 0; i < KBC_MAX_GPIO; i++) { 222 u32 row_cfg, col_cfg; 223 u32 r_shift = 5 * (i % 6); 224 u32 c_shift = 4 * (i % 8); 225 u32 r_mask = 0x1f << r_shift; 226 u32 c_mask = 0xf << c_shift; 227 u32 r_offs = i / 6; 228 u32 c_offs = i / 8; 229 230 row_cfg = readl(&kbc->row_cfg[r_offs]); 231 col_cfg = readl(&kbc->col_cfg[c_offs]); 232 233 row_cfg &= ~r_mask; 234 col_cfg &= ~c_mask; 235 236 if (i < config.matrix.num_rows) { 237 row_cfg |= ((i << 1) | 1) << r_shift; 238 } else { 239 col_cfg |= (((i - config.matrix.num_rows) << 1) | 1) 240 << c_shift; 241 } 242 243 writel(row_cfg, &kbc->row_cfg[r_offs]); 244 writel(col_cfg, &kbc->col_cfg[c_offs]); 245 } 246 } 247 248 /** 249 * Start up the keyboard device 250 */ 251 static void tegra_kbc_open(void) 252 { 253 struct kbc_tegra *kbc = config.kbc; 254 unsigned int scan_period; 255 u32 val; 256 257 /* 258 * We will scan at twice the keyboard repeat rate, so that there is 259 * always a scan ready when we check it in check_for_keys(). 260 */ 261 scan_period = KBC_REPEAT_RATE_MS / 2; 262 writel(scan_period * KBC_CLOCK_KHZ, &kbc->rpt_dly); 263 writel(scan_period * KBC_CLOCK_KHZ, &kbc->init_dly); 264 /* 265 * Before reading from the keyboard we must wait for the init_dly 266 * plus the rpt_delay, plus 2ms for the row scan time. 267 */ 268 config.init_dly_ms = scan_period * 2 + 2; 269 270 val = KBC_DEBOUNCE_COUNT << KBC_DEBOUNCE_CNT_SHIFT; 271 val |= 1 << KBC_FIFO_TH_CNT_SHIFT; /* fifo interrupt threshold */ 272 val |= KBC_CONTROL_KBC_EN; /* enable */ 273 writel(val, &kbc->control); 274 275 config.start_time_ms = get_timer(0); 276 config.last_poll_ms = config.next_repeat_ms = get_timer(0); 277 config.first_scan = 1; 278 } 279 280 /** 281 * Set up the tegra keyboard. This is called by the stdio device handler 282 * 283 * We want to do this init when the keyboard is actually used rather than 284 * at start-up, since keyboard input may not currently be selected. 285 * 286 * Once the keyboard starts there will be a period during which we must 287 * wait for the keyboard to init. We do this only when a key is first 288 * read - see kbd_wait_for_fifo_init(). 289 * 290 * @return 0 if ok, -ve on error 291 */ 292 static int init_tegra_keyboard(struct stdio_dev *dev) 293 { 294 /* check if already created */ 295 if (config.created) 296 return 0; 297 298 #if CONFIG_IS_ENABLED(OF_CONTROL) 299 int node; 300 301 node = fdtdec_next_compatible(gd->fdt_blob, 0, 302 COMPAT_NVIDIA_TEGRA20_KBC); 303 if (node < 0) { 304 debug("%s: cannot locate keyboard node\n", __func__); 305 return node; 306 } 307 config.kbc = (struct kbc_tegra *)fdtdec_get_addr(gd->fdt_blob, 308 node, "reg"); 309 if ((fdt_addr_t)config.kbc == FDT_ADDR_T_NONE) { 310 debug("%s: No keyboard register found\n", __func__); 311 return -1; 312 } 313 input_set_delays(&config.input, KBC_REPEAT_DELAY_MS, 314 KBC_REPEAT_RATE_MS); 315 316 /* Decode the keyboard matrix information (16 rows, 8 columns) */ 317 if (key_matrix_init(&config.matrix, 16, 8, 1)) { 318 debug("%s: Could not init key matrix\n", __func__); 319 return -1; 320 } 321 if (key_matrix_decode_fdt(&config.matrix, gd->fdt_blob, node)) { 322 debug("%s: Could not decode key matrix from fdt\n", __func__); 323 return -1; 324 } 325 if (config.matrix.fn_keycode) { 326 if (input_add_table(&config.input, KEY_FN, -1, 327 config.matrix.fn_keycode, 328 config.matrix.key_count)) 329 return -1; 330 } 331 #else 332 #error "Tegra keyboard driver requires FDT definitions" 333 #endif 334 335 /* Set up pin mux and enable the clock */ 336 funcmux_select(PERIPH_ID_KBC, FUNCMUX_DEFAULT); 337 clock_enable(PERIPH_ID_KBC); 338 config_kbc_gpio(config.kbc); 339 340 tegra_kbc_open(); 341 config.created = 1; 342 debug("%s: Tegra keyboard ready\n", __func__); 343 344 return 0; 345 } 346 347 int drv_keyboard_init(void) 348 { 349 struct stdio_dev dev; 350 char *stdinname = getenv("stdin"); 351 int error; 352 353 if (input_init(&config.input, 0)) { 354 debug("%s: Cannot set up input\n", __func__); 355 return -1; 356 } 357 config.input.read_keys = tegra_kbc_check; 358 359 memset(&dev, '\0', sizeof(dev)); 360 strcpy(dev.name, "tegra-kbc"); 361 dev.flags = DEV_FLAGS_INPUT | DEV_FLAGS_SYSTEM; 362 dev.getc = kbd_getc; 363 dev.tstc = kbd_tstc; 364 dev.start = init_tegra_keyboard; 365 366 /* Register the device. init_tegra_keyboard() will be called soon */ 367 error = input_stdio_register(&dev); 368 if (error) 369 return error; 370 #ifdef CONFIG_CONSOLE_MUX 371 error = iomux_doenv(stdin, stdinname); 372 if (error) 373 return error; 374 #endif 375 return 0; 376 } 377