diff options
Diffstat (limited to 'drivers/input')
| -rw-r--r-- | drivers/input/tegra-kbc.c | 375 |
1 files changed, 375 insertions, 0 deletions
diff --git a/drivers/input/tegra-kbc.c b/drivers/input/tegra-kbc.c new file mode 100644 index 000000000..f164791be --- /dev/null +++ b/drivers/input/tegra-kbc.c @@ -0,0 +1,375 @@ +/* + * (C) Copyright 2011 + * NVIDIA Corporation <www.nvidia.com> + * + * See file CREDITS for list of people who contributed to this + * project. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + */ + +#include <common.h> +#include <fdtdec.h> +#include <input.h> +#include <key_matrix.h> +#include <stdio_dev.h> +#include <tegra-kbc.h> +#include <asm/io.h> +#include <asm/arch/clock.h> +#include <asm/arch/funcmux.h> +#include <asm/arch/timer.h> +#include <linux/input.h> + +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 */ + + /* + * 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 + */ +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(void) +{ + /* 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(void) +{ + /* 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(void) +{ +#ifdef CONFIG_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; + } + + /* Decode the keyboard matrix information (16 rows, 8 columns) */ + if (key_matrix_init(&config.matrix, 16, 8)) { + 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(); + debug("%s: Tegra keyboard ready\n", __func__); + + return 0; +} + +int drv_keyboard_init(void) +{ + struct stdio_dev dev; + + if (input_init(&config.input, 0, KBC_REPEAT_DELAY_MS, + KBC_REPEAT_RATE_MS)) { + 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 */ + return input_stdio_register(&dev); +} |