mec1322: keyboard scan support

This adds keyboard scan module driver. Keyboard scan task is not enabled
yet as the LPC layer is not finished and thus i8042 protocol cannot be
enabled.

Since KSO00-KSO03 are used as JTAG, we use KSO04-KSO16 so as to preserve
JTAG functionality. Unfortunately we don't have enough KSO pins, so
trace debug port must be disabled, as done in this CL.

BUG=chrome-os-partner:24107
TEST=Set 'ksstate on'. Short KSI pins and KSO pins, and see
corresponding key shown as pressed.
TEST=Check keypress is detected when console shows 'KB wait'.
BRANCH=None

Change-Id: I366a27453ef95030d251e525313eb4627eb4340f
Signed-off-by: Vic (Chun-Ju) Yang <victoryang@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/179319
Reviewed-by: Randall Spangler <rspangler@chromium.org>

5 files changed, 91 insertions, 0 deletions

diff --git a/board/mec1322_evb/board.c b/board/mec1322_evb/board.c
index ced2c5ab27..f70fe5749d 100644
--- a/board/mec1322_evb/board.c
+++ b/board/mec1322_evb/board.c
@@ -10,6 +10,9 @@
 #include "registers.h"
 #include "util.h"
 
+#define GPIO_KB_INPUT GPIO_INPUT
+#define GPIO_KB_OUTPUT (GPIO_ODR_HIGH | GPIO_PULL_UP)
+
 /* GPIO signal list.  Must match order from enum gpio_signal. */
 const struct gpio_info gpio_list[] = {
 	{"LED1", GPIO_PORT(15), (1 << 4), GPIO_ODR_LOW, NULL},
@@ -28,6 +31,13 @@ const struct gpio_alt_func gpio_alt_funcs[] = {
 	{GPIO_PORT(3),  (1 << 4), 3, MODULE_PWM_FAN},
 	{GPIO_PORT(14), (1 << 0), 3, MODULE_PWM_FAN},
 	{GPIO_PORT(1),  0x60,     2, MODULE_I2C},  /* I2C0 */
+	{GPIO_PORT(0),  0xfe,     3, MODULE_KEYBOARD_SCAN, GPIO_KB_OUTPUT},
+	{GPIO_PORT(1),  0x03,     3, MODULE_KEYBOARD_SCAN, GPIO_KB_OUTPUT},
+	{GPIO_PORT(3),  0x04,     3, MODULE_KEYBOARD_SCAN, GPIO_KB_INPUT},
+	{GPIO_PORT(4),  0x0d,     3, MODULE_KEYBOARD_SCAN, GPIO_KB_INPUT},
+	{GPIO_PORT(10), 0xd8,     3, MODULE_KEYBOARD_SCAN, GPIO_KB_OUTPUT},
+	{GPIO_PORT(12), 0x60,     2, MODULE_KEYBOARD_SCAN, GPIO_KB_INPUT},
+	{GPIO_PORT(14), 0x14,     3, MODULE_KEYBOARD_SCAN, GPIO_KB_INPUT},
 };
 const int gpio_alt_funcs_count = ARRAY_SIZE(gpio_alt_funcs);
 
diff --git a/chip/mec1322/build.mk b/chip/mec1322/build.mk
index bbc040a284..60376d1a5f 100644
--- a/chip/mec1322/build.mk
+++ b/chip/mec1322/build.mk
@@ -18,3 +18,4 @@ chip-$(CONFIG_I2C)+=i2c.o
 chip-$(CONFIG_LPC)+=lpc.o
 chip-$(CONFIG_PWM)+=pwm.o
 chip-$(CONFIG_WATCHDOG)+=watchdog.o
+chip-$(HAS_TASK_KEYSCAN)+=keyboard_raw.o
diff --git a/chip/mec1322/keyboard_raw.c b/chip/mec1322/keyboard_raw.c
new file mode 100644
index 0000000000..155ff839f2
--- /dev/null
+++ b/chip/mec1322/keyboard_raw.c
@@ -0,0 +1,66 @@
+/* Copyright (c) 2013 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.
+ *
+ * Raw keyboard I/O layer for MEC1322
+ */
+
+#include "gpio.h"
+#include "keyboard_config.h"
+#include "keyboard_raw.h"
+#include "keyboard_scan.h"
+#include "registers.h"
+#include "task.h"
+#include "util.h"
+
+void keyboard_raw_init(void)
+{
+	keyboard_raw_enable_interrupt(0);
+	gpio_config_module(MODULE_KEYBOARD_SCAN, 1);
+
+	/* Enable keyboard scan interrupt */
+	MEC1322_INT_ENABLE(17) |= 1 << 21;
+	MEC1322_INT_BLK_EN |= 1 << 17;
+	MEC1322_KS_KSI_INT_EN = 0xff;
+}
+
+void keyboard_raw_task_start(void)
+{
+	task_enable_irq(MEC1322_IRQ_KSC_INT);
+}
+
+test_mockable void keyboard_raw_drive_column(int out)
+{
+	if (out == KEYBOARD_COLUMN_ALL)
+		MEC1322_KS_KSO_SEL = 1 << 5; /* KSEN=0, KSALL=1 */
+	else if (out == KEYBOARD_COLUMN_NONE)
+		MEC1322_KS_KSO_SEL = 1 << 6; /* KSEN=1 */
+	else
+		MEC1322_KS_KSO_SEL = out + 4; /* KSO starts from KSO04 */
+}
+
+test_mockable int keyboard_raw_read_rows(void)
+{
+	/* Invert it so 0=not pressed, 1=pressed */
+	return (MEC1322_KS_KSI_INPUT & 0xff) ^ 0xff;
+}
+
+void keyboard_raw_enable_interrupt(int enable)
+{
+	if (enable) {
+		task_clear_pending_irq(MEC1322_IRQ_KSC_INT);
+		task_enable_irq(MEC1322_IRQ_KSC_INT);
+	} else {
+		task_disable_irq(MEC1322_IRQ_KSC_INT);
+	}
+}
+
+static void keyboard_raw_interrupt(void)
+{
+	/* Clear interrupt status bits */
+	MEC1322_KS_KSI_STATUS = 0xff;
+
+	/* Wake keyboard scan task to handle interrupt */
+	task_wake(TASK_ID_KEYSCAN);
+}
+DECLARE_IRQ(MEC1322_IRQ_KSC_INT, keyboard_raw_interrupt, 1);
diff --git a/chip/mec1322/registers.h b/chip/mec1322/registers.h
index 3f9c350c5c..4972681047 100644
--- a/chip/mec1322/registers.h
+++ b/chip/mec1322/registers.h
@@ -41,6 +41,8 @@
 /* EC Subsystem */
 #define MEC1322_EC_BASE        0x4000fc00
 #define MEC1322_EC_INT_CTRL    REG32(MEC1322_EC_BASE + 0x18)
+#define MEC1322_EC_TRACE_EN    REG32(MEC1322_EC_BASE + 0x1c)
+#define MEC1322_EC_JTAG_EN     REG32(MEC1322_EC_BASE + 0x20)
 
 
 /* Interrupt aggregator */
@@ -240,6 +242,15 @@ static inline uintptr_t gpio_port_base(int port_id)
 #define MEC1322_I2C_MASTER_RX_BUF(port) REG8(MEC1322_I2C_ADDR(port, 0x54))
 
 
+/* Keyboard scan matrix */
+#define MEC1322_KS_BASE        0x40009c00
+#define MEC1322_KS_KSO_SEL     REG32(MEC1322_KS_BASE + 0x4)
+#define MEC1322_KS_KSI_INPUT   REG32(MEC1322_KS_BASE + 0x8)
+#define MEC1322_KS_KSI_STATUS  REG32(MEC1322_KS_BASE + 0xc)
+#define MEC1322_KS_KSI_INT_EN  REG32(MEC1322_KS_BASE + 0x10)
+#define MEC1322_KS_EXT_CTRL    REG32(MEC1322_KS_BASE + 0x14)
+
+
 /* IRQ Numbers */
 #define MEC1322_IRQ_I2C_0        0
 #define MEC1322_IRQ_I2C_1        1
diff --git a/chip/mec1322/system.c b/chip/mec1322/system.c
index 7425ccc30f..aa7b36e459 100644
--- a/chip/mec1322/system.c
+++ b/chip/mec1322/system.c
@@ -47,6 +47,9 @@ void system_pre_init(void)
 	/* Enable direct NVIC */
 	MEC1322_EC_INT_CTRL |= 1;
 
+	/* Disable ARM TRACE debug port */
+	MEC1322_EC_TRACE_EN &= ~1;
+
 	/* Deassert nSIO_RESET */
 	MEC1322_PCR_PWR_RST_CTL &= ~(1 << 0);