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 0000000..f164791
--- /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);
+}