1 files changed, 137 insertions, 0 deletions
diff --git a/common/i8042.c b/common/i8042.c
new file mode 100644
index 0000000000..42c6095ecc
--- /dev/null
+++ b/common/i8042.c
@@ -0,0 +1,137 @@
+/* Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ *
+ * Chrome OS EC i8042 interface code.
+ */
+
+#include "board.h"
+#include "common.h"
+#include "i8042.h"
+#include "keyboard.h"
+/* TODO: Code in common.c should not directly access chip registers */
+#include "registers.h"
+#include "task.h"
+#include "timer.h"
+#include "uart.h"
+#include "util.h"
+
+
+#define I8042_DEBUG 1
+
+#define MAX_QUEUED_KEY_PRESS 16
+
+/* Circular buffer to host.
+ * head: next to dequeqe
+ * tail: next to enqueue
+ * head == tail: empty.
+ * tail + 1 == head: full
+ */
+static int head_to_buffer = 0;
+static int tail_to_buffer = 0;
+#define HOST_BUFFER_SIZE (16)
+static uint8_t to_host_buffer[HOST_BUFFER_SIZE];
+
+
+void i8042_init()
+{
+	head_to_buffer = tail_to_buffer = 0;
+	LM4_LPC_ST(3) = 0;  /* clear the TOH bit */
+}
+
+
+void i8042_receives_data(int data)
+{
+	int ret_len;
+	uint8_t output[MAX_SCAN_CODE_LEN];
+	enum ec_error_list ret;
+
+	ret_len = handle_keyboard_data(data, output);
+	ret = i8042_send_to_host(ret_len, output);
+	ASSERT(ret == EC_SUCCESS);
+}
+
+
+void i8042_receives_command(int cmd)
+{
+	int ret_len;
+	uint8_t output[MAX_SCAN_CODE_LEN];
+	enum ec_error_list ret;
+
+	ret_len = handle_keyboard_command(cmd, output);
+	ret = i8042_send_to_host(ret_len, output);
+	ASSERT(ret == EC_SUCCESS);
+}
+
+
+static void enq_to_host(int len, uint8_t *to_host)
+{
+	int from, to;
+
+	/* TODO: need atomic protection */
+	if ((tail_to_buffer + len) <= (head_to_buffer + HOST_BUFFER_SIZE - 1)) {
+		for (from = 0, to = tail_to_buffer; from < len;) {
+			to_host_buffer[to++] = to_host[from++];
+			to %= HOST_BUFFER_SIZE;
+		}
+		tail_to_buffer = (tail_to_buffer + len) % HOST_BUFFER_SIZE;
+	}
+	/* end of atomic protection */
+}
+
+
+void i8042_command_task(void)
+{
+	while (1) {
+		/* Either a new byte to host or host picking up can un-block. */
+		task_wait_msg(-1);
+
+		while (1) {
+			uint8_t chr;
+			int empty = 0;
+
+			/* TODO: need atomic protection */
+			if (head_to_buffer == tail_to_buffer) {
+				empty = 1;  /* nothing to host */
+			}
+			/* end of atomic protection */
+			if (empty) break;
+
+			/* if the host still didn't read that away,
+			   try next time. */
+			if (LM4_LPC_ST(3) & (1 << 0 /* TOH */)) {
+#if I8042_DEBUG >= 5
+				uart_printf("[%d] i8042_command_task() "
+					    "cannot send to host due to TOH\n",
+					    get_time().le.lo);
+#endif
+				break;
+			}
+
+			/* TODO: need atomic protection */
+			chr = to_host_buffer[head_to_buffer];
+			head_to_buffer =
+				(head_to_buffer + 1) % HOST_BUFFER_SIZE;
+			/* end of atomic protection */
+
+			/* Write to host. TOH is set automatically. */
+			LPC_POOL_KEYBOARD[1] = chr;
+#if I8042_DEBUG >= 4
+			uart_printf("[%d] i8042_command_task() "
+				    "sends to host: 0x%02x\n",
+				    get_time().le.lo, chr);
+#endif
+		}
+	}
+}
+
+
+enum ec_error_list i8042_send_to_host(int len, uint8_t *to_host)
+{
+	enq_to_host(len, to_host);
+
+	/* Wake up the task to handle the command */
+	task_send_msg(TASK_ID_I8042CMD, TASK_ID_I8042CMD, 0);
+
+	return EC_SUCCESS;
+}