1// SPDX-License-Identifier: GPL-2.0+ 2/* 3 * (C) Copyright 2011 4 * NVIDIA Corporation <www.nvidia.com> 5 */ 6 7#include <dm.h> 8#include <fdtdec.h> 9#include <input.h> 10#include <keyboard.h> 11#include <key_matrix.h> 12#include <log.h> 13#include <stdio_dev.h> 14#include <tegra-kbc.h> 15#include <time.h> 16#include <asm/io.h> 17#include <asm/arch/clock.h> 18#include <asm/arch/funcmux.h> 19#include <asm/arch-tegra/timer.h> 20#include <linux/delay.h> 21#include <linux/input.h> 22 23enum { 24 KBC_MAX_GPIO = 24, 25 KBC_MAX_KPENT = 8, /* size of keypress entry queue */ 26}; 27 28#define KBC_FIFO_TH_CNT_SHIFT 14 29#define KBC_DEBOUNCE_CNT_SHIFT 4 30#define KBC_CONTROL_FIFO_CNT_INT_EN (1 << 3) 31#define KBC_CONTROL_KBC_EN (1 << 0) 32#define KBC_INT_FIFO_CNT_INT_STATUS (1 << 2) 33#define KBC_KPENT_VALID (1 << 7) 34#define KBC_ST_STATUS (1 << 3) 35 36enum { 37 KBC_DEBOUNCE_COUNT = 2, 38 KBC_REPEAT_RATE_MS = 30, 39 KBC_REPEAT_DELAY_MS = 240, 40 KBC_CLOCK_KHZ = 32, /* Keyboard uses a 32KHz clock */ 41}; 42 43/* keyboard controller config and state */ 44struct tegra_kbd_priv { 45 struct input_config *input; /* The input layer */ 46 struct key_matrix matrix; /* The key matrix layer */ 47 48 struct kbc_tegra *kbc; /* tegra keyboard controller */ 49 unsigned char inited; /* 1 if keyboard has been inited */ 50 unsigned char first_scan; /* 1 if this is our first key scan */ 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}; 62 63/** 64 * reads the keyboard fifo for current keypresses 65 * 66 * @param priv Keyboard private data 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 */ 71static int tegra_kbc_find_keys(struct tegra_kbd_priv *priv, 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(&priv->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(&priv->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 priv Keyboard private data 110 * @param fifo_cnt Number of entries in the keyboard fifo 111 */ 112static void process_fifo(struct tegra_kbd_priv *priv, 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(priv, fifo, KBC_MAX_KPENT); 121 122 input_send_keycodes(priv->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 priv Keyboard private data 131 */ 132static void check_for_keys(struct tegra_kbd_priv *priv) 133{ 134 int fifo_cnt; 135 136 if (!priv->first_scan && 137 get_timer(priv->last_poll_ms) < KBC_REPEAT_RATE_MS) 138 return; 139 priv->last_poll_ms = get_timer(0); 140 priv->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(&priv->kbc->interrupt) >> 4) & 0xf; 147 process_fifo(priv, 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 priv Keyboard private data 157 */ 158static void kbd_wait_for_fifo_init(struct tegra_kbd_priv *priv) 159{ 160 if (!priv->inited) { 161 unsigned long elapsed_time; 162 long delay_ms; 163 164 elapsed_time = get_timer(priv->start_time_ms); 165 delay_ms = priv->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 priv->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 */ 184static int tegra_kbc_check(struct input_config *input) 185{ 186 struct tegra_kbd_priv *priv = dev_get_priv(input->dev); 187 188 kbd_wait_for_fifo_init(priv); 189 check_for_keys(priv); 190 191 return 1; 192} 193 194/* configures keyboard GPIO registers to use the rows and columns */ 195static void config_kbc_gpio(struct tegra_kbd_priv *priv, struct kbc_tegra *kbc) 196{ 197 int i; 198 199 for (i = 0; i < KBC_MAX_GPIO; i++) { 200 u32 row_cfg, col_cfg; 201 u32 r_shift = 5 * (i % 6); 202 u32 c_shift = 4 * (i % 8); 203 u32 r_mask = 0x1f << r_shift; 204 u32 c_mask = 0xf << c_shift; 205 u32 r_offs = i / 6; 206 u32 c_offs = i / 8; 207 208 row_cfg = readl(&kbc->row_cfg[r_offs]); 209 col_cfg = readl(&kbc->col_cfg[c_offs]); 210 211 row_cfg &= ~r_mask; 212 col_cfg &= ~c_mask; 213 214 if (i < priv->matrix.num_rows) { 215 row_cfg |= ((i << 1) | 1) << r_shift; 216 } else { 217 col_cfg |= (((i - priv->matrix.num_rows) << 1) | 1) 218 << c_shift; 219 } 220 221 writel(row_cfg, &kbc->row_cfg[r_offs]); 222 writel(col_cfg, &kbc->col_cfg[c_offs]); 223 } 224} 225 226/** 227 * Start up the keyboard device 228 */ 229static void tegra_kbc_open(struct tegra_kbd_priv *priv) 230{ 231 struct kbc_tegra *kbc = priv->kbc; 232 unsigned int scan_period; 233 u32 val; 234 235 /* 236 * We will scan at twice the keyboard repeat rate, so that there is 237 * always a scan ready when we check it in check_for_keys(). 238 */ 239 scan_period = KBC_REPEAT_RATE_MS / 2; 240 writel(scan_period * KBC_CLOCK_KHZ, &kbc->rpt_dly); 241 writel(scan_period * KBC_CLOCK_KHZ, &kbc->init_dly); 242 /* 243 * Before reading from the keyboard we must wait for the init_dly 244 * plus the rpt_delay, plus 2ms for the row scan time. 245 */ 246 priv->init_dly_ms = scan_period * 2 + 2; 247 248 val = KBC_DEBOUNCE_COUNT << KBC_DEBOUNCE_CNT_SHIFT; 249 val |= 1 << KBC_FIFO_TH_CNT_SHIFT; /* fifo interrupt threshold */ 250 val |= KBC_CONTROL_KBC_EN; /* enable */ 251 writel(val, &kbc->control); 252 253 priv->start_time_ms = get_timer(0); 254 priv->last_poll_ms = get_timer(0); 255 priv->next_repeat_ms = priv->last_poll_ms; 256 priv->first_scan = 1; 257} 258 259static int tegra_kbd_start(struct udevice *dev) 260{ 261 struct tegra_kbd_priv *priv = dev_get_priv(dev); 262 263 /* Set up pin mux and enable the clock */ 264 funcmux_select(PERIPH_ID_KBC, FUNCMUX_DEFAULT); 265 clock_enable(PERIPH_ID_KBC); 266 config_kbc_gpio(priv, priv->kbc); 267 268 tegra_kbc_open(priv); 269 debug("%s: Tegra keyboard ready\n", __func__); 270 271 return 0; 272} 273 274/** 275 * Set up the tegra keyboard. This is called by the stdio device handler 276 * 277 * We want to do this init when the keyboard is actually used rather than 278 * at start-up, since keyboard input may not currently be selected. 279 * 280 * Once the keyboard starts there will be a period during which we must 281 * wait for the keyboard to init. We do this only when a key is first 282 * read - see kbd_wait_for_fifo_init(). 283 * 284 * Return: 0 if ok, -ve on error 285 */ 286static int tegra_kbd_probe(struct udevice *dev) 287{ 288 struct tegra_kbd_priv *priv = dev_get_priv(dev); 289 struct keyboard_priv *uc_priv = dev_get_uclass_priv(dev); 290 struct stdio_dev *sdev = &uc_priv->sdev; 291 struct input_config *input = &uc_priv->input; 292 int ret; 293 294 priv->kbc = dev_read_addr_ptr(dev); 295 if ((fdt_addr_t)priv->kbc == FDT_ADDR_T_NONE) { 296 debug("%s: No keyboard register found\n", __func__); 297 return -EINVAL; 298 } 299 input_set_delays(input, KBC_REPEAT_DELAY_MS, KBC_REPEAT_RATE_MS); 300 301 /* Decode the keyboard matrix information (16 rows, 8 columns) */ 302 ret = key_matrix_init(&priv->matrix, 16, 8, 1); 303 if (ret) { 304 debug("%s: Could not init key matrix: %d\n", __func__, ret); 305 return ret; 306 } 307 ret = key_matrix_decode_fdt(dev, &priv->matrix); 308 if (ret) { 309 debug("%s: Could not decode key matrix from fdt: %d\n", 310 __func__, ret); 311 return ret; 312 } 313 input_add_tables(input, false); 314 if (priv->matrix.fn_keycode) { 315 ret = input_add_table(input, KEY_FN, -1, 316 priv->matrix.fn_keycode, 317 priv->matrix.key_count); 318 if (ret) { 319 debug("%s: input_add_table() failed\n", __func__); 320 return ret; 321 } 322 } 323 324 /* Register the device. init_tegra_keyboard() will be called soon */ 325 priv->input = input; 326 input->dev = dev; 327 input->read_keys = tegra_kbc_check; 328 strcpy(sdev->name, "tegra-kbc"); 329 ret = input_stdio_register(sdev); 330 if (ret) { 331 debug("%s: input_stdio_register() failed\n", __func__); 332 return ret; 333 } 334 335 return 0; 336} 337 338static const struct keyboard_ops tegra_kbd_ops = { 339 .start = tegra_kbd_start, 340}; 341 342static const struct udevice_id tegra_kbd_ids[] = { 343 { .compatible = "nvidia,tegra20-kbc" }, 344 { } 345}; 346 347U_BOOT_DRIVER(tegra_kbd) = { 348 .name = "tegra_kbd", 349 .id = UCLASS_KEYBOARD, 350 .of_match = tegra_kbd_ids, 351 .probe = tegra_kbd_probe, 352 .ops = &tegra_kbd_ops, 353 .priv_auto = sizeof(struct tegra_kbd_priv), 354}; 355