--- /dev/null
+/*
+ * (C) Copyright 2011
+ * NVIDIA Corporation <www.nvidia.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#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-tegra/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 */
+ 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
+ */
+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)
+{
+ /* check if already created */
+ if (config.created)
+ return 0;
+
+#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;
+ }
+ 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;
+}
Code Review / kvmfornfv.git / blobdiff