/* * (C) Copyright 2011 * NVIDIA Corporation * * SPDX-License-Identifier: GPL-2.0+ */ #include #include #include #include #include #include #include #include #include #include #include DECLARE_GLOBAL_DATA_PTR; enum { KBC_MAX_GPIO = 24, KBC_MAX_KPENT = 8, /* size of keypress entry queue */ }; #define KBC_FIFO_TH_CNT_SHIFT 14 #define KBC_DEBOUNCE_CNT_SHIFT 4 #define KBC_CONTROL_FIFO_CNT_INT_EN (1 << 3) #define KBC_CONTROL_KBC_EN (1 << 0) #define KBC_INT_FIFO_CNT_INT_STATUS (1 << 2) #define KBC_KPENT_VALID (1 << 7) #define KBC_ST_STATUS (1 << 3) enum { KBC_DEBOUNCE_COUNT = 2, KBC_REPEAT_RATE_MS = 30, KBC_REPEAT_DELAY_MS = 240, KBC_CLOCK_KHZ = 32, /* Keyboard uses a 32KHz clock */ }; /* keyboard controller config and state */ static struct keyb { struct input_config input; /* The input layer */ struct key_matrix matrix; /* The key matrix layer */ struct kbc_tegra *kbc; /* tegra keyboard controller */ unsigned char inited; /* 1 if keyboard has been inited */ unsigned char first_scan; /* 1 if this is our first key scan */ unsigned char created; /* 1 if driver has been created */ /* * After init we must wait a short time before polling the keyboard. * This gives the tegra keyboard controller time to react after reset * and lets us grab keys pressed during reset. */ unsigned int init_dly_ms; /* Delay before we can read keyboard */ unsigned int start_time_ms; /* Time that we inited (in ms) */ unsigned int last_poll_ms; /* Time we should last polled */ unsigned int next_repeat_ms; /* Next time we repeat a key */ } config; /** * reads the keyboard fifo for current keypresses * * @param config Keyboard config * @param fifo Place to put fifo results * @param max_keycodes Maximum number of key codes to put in the fifo * @return number of items put into fifo */ static int tegra_kbc_find_keys(struct keyb *config, int *fifo, int max_keycodes) { struct key_matrix_key keys[KBC_MAX_KPENT], *key; u32 kp_ent = 0; int i; for (key = keys, i = 0; i < KBC_MAX_KPENT; i++, key++) { /* Get next word */ if (!(i & 3)) kp_ent = readl(&config->kbc->kp_ent[i / 4]); key->valid = (kp_ent & KBC_KPENT_VALID) != 0; key->row = (kp_ent >> 3) & 0xf; key->col = kp_ent & 0x7; /* Shift to get next entry */ kp_ent >>= 8; } return key_matrix_decode(&config->matrix, keys, KBC_MAX_KPENT, fifo, max_keycodes); } /** * Process all the keypress sequences in fifo and send key codes * * The fifo contains zero or more keypress sets. Each set * consists of from 1-8 keycodes, representing the keycodes which * were simultaneously pressed during that scan. * * This function works through each set and generates ASCII characters * for each. Not that one set may produce more than one ASCII characters - * for example holding down 'd' and 'f' at the same time will generate * two ASCII characters. * * Note: if fifo_cnt is 0, we will tell the input layer that no keys are * pressed. * * @param config Keyboard config * @param fifo_cnt Number of entries in the keyboard fifo */ static void process_fifo(struct keyb *config, int fifo_cnt) { int fifo[KBC_MAX_KPENT]; int cnt = 0; /* Always call input_send_keycodes() at least once */ do { if (fifo_cnt) cnt = tegra_kbc_find_keys(config, fifo, KBC_MAX_KPENT); input_send_keycodes(&config->input, fifo, cnt); } while (--fifo_cnt > 0); } /** * Check the keyboard controller and emit ASCII characters for any keys that * are pressed. * * @param config Keyboard config */ static void check_for_keys(struct keyb *config) { int fifo_cnt; if (!config->first_scan && get_timer(config->last_poll_ms) < KBC_REPEAT_RATE_MS) return; config->last_poll_ms = get_timer(0); config->first_scan = 0; /* * Once we get here we know the keyboard has been scanned. So if there * scan waiting for us, we know that nothing is held down. */ fifo_cnt = (readl(&config->kbc->interrupt) >> 4) & 0xf; process_fifo(config, fifo_cnt); } /** * In order to detect keys pressed on boot, wait for the hardware to * complete scanning the keys. This includes time to transition from * Wkup mode to Continous polling mode and the repoll time. We can * deduct the time that's already elapsed. * * @param config Keyboard config */ static void kbd_wait_for_fifo_init(struct keyb *config) { if (!config->inited) { unsigned long elapsed_time; long delay_ms; elapsed_time = get_timer(config->start_time_ms); delay_ms = config->init_dly_ms - elapsed_time; if (delay_ms > 0) { udelay(delay_ms * 1000); debug("%s: delay %ldms\n", __func__, delay_ms); } config->inited = 1; } } /** * Check the tegra keyboard, and send any keys that are pressed. * * This is called by input_tstc() and input_getc() when they need more * characters * * @param input Input configuration * @return 1, to indicate that we have something to look at */ static int tegra_kbc_check(struct input_config *input) { kbd_wait_for_fifo_init(&config); check_for_keys(&config); return 1; } /** * Test if keys are available to be read * * @return 0 if no keys available, 1 if keys are available */ static int kbd_tstc(struct stdio_dev *dev) { /* Just get input to do this for us */ return input_tstc(&config.input); } /** * Read a key * * TODO: U-Boot wants 0 for no key, but Ctrl-@ is a valid key... * * @return ASCII key code, or 0 if no key, or -1 if error */ static int kbd_getc(struct stdio_dev *dev) { /* Just get input to do this for us */ return input_getc(&config.input); } /* configures keyboard GPIO registers to use the rows and columns */ static void config_kbc_gpio(struct kbc_tegra *kbc) { int i; for (i = 0; i < KBC_MAX_GPIO; i++) { u32 row_cfg, col_cfg; u32 r_shift = 5 * (i % 6); u32 c_shift = 4 * (i % 8); u32 r_mask = 0x1f << r_shift; u32 c_mask = 0xf << c_shift; u32 r_offs = i / 6; u32 c_offs = i / 8; row_cfg = readl(&kbc->row_cfg[r_offs]); col_cfg = readl(&kbc->col_cfg[c_offs]); row_cfg &= ~r_mask; col_cfg &= ~c_mask; if (i < config.matrix.num_rows) { row_cfg |= ((i << 1) | 1) << r_shift; } else { col_cfg |= (((i - config.matrix.num_rows) << 1) | 1) << c_shift; } writel(row_cfg, &kbc->row_cfg[r_offs]); writel(col_cfg, &kbc->col_cfg[c_offs]); } } /** * Start up the keyboard device */ static void tegra_kbc_open(void) { struct kbc_tegra *kbc = config.kbc; unsigned int scan_period; u32 val; /* * We will scan at twice the keyboard repeat rate, so that there is * always a scan ready when we check it in check_for_keys(). */ scan_period = KBC_REPEAT_RATE_MS / 2; writel(scan_period * KBC_CLOCK_KHZ, &kbc->rpt_dly); writel(scan_period * KBC_CLOCK_KHZ, &kbc->init_dly); /* * Before reading from the keyboard we must wait for the init_dly * plus the rpt_delay, plus 2ms for the row scan time. */ config.init_dly_ms = scan_period * 2 + 2; val = KBC_DEBOUNCE_COUNT << KBC_DEBOUNCE_CNT_SHIFT; val |= 1 << KBC_FIFO_TH_CNT_SHIFT; /* fifo interrupt threshold */ val |= KBC_CONTROL_KBC_EN; /* enable */ writel(val, &kbc->control); config.start_time_ms = get_timer(0); config.last_poll_ms = config.next_repeat_ms = get_timer(0); config.first_scan = 1; } /** * Set up the tegra keyboard. This is called by the stdio device handler * * We want to do this init when the keyboard is actually used rather than * at start-up, since keyboard input may not currently be selected. * * Once the keyboard starts there will be a period during which we must * wait for the keyboard to init. We do this only when a key is first * read - see kbd_wait_for_fifo_init(). * * @return 0 if ok, -ve on error */ static int init_tegra_keyboard(struct stdio_dev *dev) { /* check if already created */ if (config.created) return 0; #if CONFIG_IS_ENABLED(OF_CONTROL) int node; node = fdtdec_next_compatible(gd->fdt_blob, 0, COMPAT_NVIDIA_TEGRA20_KBC); if (node < 0) { debug("%s: cannot locate keyboard node\n", __func__); return node; } config.kbc = (struct kbc_tegra *)fdtdec_get_addr(gd->fdt_blob, node, "reg"); if ((fdt_addr_t)config.kbc == FDT_ADDR_T_NONE) { debug("%s: No keyboard register found\n", __func__); return -1; } input_set_delays(&config.input, KBC_REPEAT_DELAY_MS, KBC_REPEAT_RATE_MS); /* Decode the keyboard matrix information (16 rows, 8 columns) */ if (key_matrix_init(&config.matrix, 16, 8, 1)) { debug("%s: Could not init key matrix\n", __func__); return -1; } if (key_matrix_decode_fdt(&config.matrix, gd->fdt_blob, node)) { debug("%s: Could not decode key matrix from fdt\n", __func__); return -1; } if (config.matrix.fn_keycode) { if (input_add_table(&config.input, KEY_FN, -1, config.matrix.fn_keycode, config.matrix.key_count)) return -1; } #else #error "Tegra keyboard driver requires FDT definitions" #endif /* Set up pin mux and enable the clock */ funcmux_select(PERIPH_ID_KBC, FUNCMUX_DEFAULT); clock_enable(PERIPH_ID_KBC); config_kbc_gpio(config.kbc); tegra_kbc_open(); config.created = 1; debug("%s: Tegra keyboard ready\n", __func__); return 0; } int drv_keyboard_init(void) { struct stdio_dev dev; char *stdinname = getenv("stdin"); int error; if (input_init(&config.input, 0)) { debug("%s: Cannot set up input\n", __func__); return -1; } config.input.read_keys = tegra_kbc_check; memset(&dev, '\0', sizeof(dev)); strcpy(dev.name, "tegra-kbc"); dev.flags = DEV_FLAGS_INPUT | DEV_FLAGS_SYSTEM; dev.getc = kbd_getc; dev.tstc = kbd_tstc; dev.start = init_tegra_keyboard; /* Register the device. init_tegra_keyboard() will be called soon */ error = input_stdio_register(&dev); if (error) return error; #ifdef CONFIG_CONSOLE_MUX error = iomux_doenv(stdin, stdinname); if (error) return error; #endif return 0; }