Add keyboard_raw interface

This is the low-level platform-dependent interface to drive keyboard
columns, read rows, and handle keyboard interrupts.

Both lm4 and stm32 had something like this before, but the interfaces
weren't fully explicit or compatible.

BUG=chrome-os-partner:18360
BRANCH=none
TEST=manual

- Build all platforms.
- Boot system and test typing on keyboard.
- Hold power+refresh+esc to test boot key detection; should go to recovery.

Change-Id: Ie3bcc1d066a4da5204f0e236daeb52c4064a6213
Signed-off-by: Randall Spangler <rspangler@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/46156

1 files changed, 135 insertions, 0 deletions

diff --git a/chip/stm32/keyboard_raw.c b/chip/stm32/keyboard_raw.c
new file mode 100644
index 0000000000..e6a3dc65eb
--- /dev/null
+++ b/chip/stm32/keyboard_raw.c
@@ -0,0 +1,135 @@
+/* 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 STM32
+ *
+ * To make this code portable, we rely heavily on looping over the keyboard
+ * input and output entries in the board's gpio_list[]. Each set of inputs or
+ * outputs must be listed in consecutive, increasing order so that scan loops
+ * can iterate beginning at KB_IN00 or KB_OUT00 for however many GPIOs are
+ * utilized (KB_INPUTS or KB_OUTPUTS).
+ */
+
+#include "gpio.h"
+#include "keyboard_raw.h"
+#include "keyboard_scan.h"
+#include "registers.h"
+#include "task.h"
+#include "util.h"
+
+/* Mask of external interrupts on input lines */
+static unsigned int irq_mask;
+
+static const uint32_t kb_out_ports[] = { KB_OUT_PORT_LIST };
+
+static void set_irq_mask(void)
+{
+	int i;
+
+	for (i = GPIO_KB_IN00; i < GPIO_KB_IN00 + KB_INPUTS; i++)
+		irq_mask |= gpio_list[i].mask;
+}
+
+void keyboard_raw_init(void)
+{
+	/* Determine EXTI_PR mask to use for the board */
+	set_irq_mask();
+
+	/* Ensure interrupts are disabled in EXTI_PR */
+	keyboard_raw_enable_interrupt(0);
+}
+
+void keyboard_raw_task_start(void)
+{
+	/* Enable interrupts for keyboard matrix inputs */
+	gpio_enable_interrupt(GPIO_KB_IN00);
+	gpio_enable_interrupt(GPIO_KB_IN01);
+	gpio_enable_interrupt(GPIO_KB_IN02);
+	gpio_enable_interrupt(GPIO_KB_IN03);
+	gpio_enable_interrupt(GPIO_KB_IN04);
+	gpio_enable_interrupt(GPIO_KB_IN05);
+	gpio_enable_interrupt(GPIO_KB_IN06);
+	gpio_enable_interrupt(GPIO_KB_IN07);
+}
+
+void keyboard_raw_drive_column(int out)
+{
+	int i, done = 0;
+
+	for (i = 0; i < ARRAY_SIZE(kb_out_ports); i++) {
+		uint32_t bsrr = 0;
+		int j;
+
+		for (j = GPIO_KB_OUT00; j <= GPIO_KB_OUT12; j++) {
+			if (gpio_list[j].port != kb_out_ports[i])
+				continue;
+
+			if (out == KEYBOARD_COLUMN_ALL) {
+				/* drive low (clear bit) */
+				bsrr |= gpio_list[j].mask << 16;
+			} else if (out == KEYBOARD_COLUMN_NONE) {
+				/* put output in hi-Z state (set bit) */
+				bsrr |= gpio_list[j].mask;
+			} else if (j - GPIO_KB_OUT00 == out) {
+				/*
+				 * Drive specified output low, others => hi-Z.
+				 *
+				 * To avoid conflict, tri-state all outputs
+				 * first, then assert specified output.
+				 */
+				keyboard_raw_drive_column(KEYBOARD_COLUMN_NONE);
+				bsrr |= gpio_list[j].mask << 16;
+				done = 1;
+				break;
+			}
+		}
+
+		if (bsrr)
+			STM32_GPIO_BSRR_OFF(kb_out_ports[i]) = bsrr;
+
+		if (done)
+			break;
+	}
+}
+
+int keyboard_raw_read_rows(void)
+{
+	int i;
+	unsigned int port, prev_port = 0;
+	int state = 0;
+	uint16_t port_val = 0;
+
+	for (i = 0; i < KB_INPUTS; i++) {
+		port = gpio_list[GPIO_KB_IN00 + i].port;
+		if (port != prev_port) {
+			port_val = STM32_GPIO_IDR_OFF(port);
+			prev_port = port;
+		}
+
+		if (port_val & gpio_list[GPIO_KB_IN00 + i].mask)
+			state |= 1 << i;
+	}
+
+	/* Invert it so 0=not pressed, 1=pressed */
+	return state ^ 0xff;
+}
+
+void keyboard_raw_enable_interrupt(int enable)
+{
+	if (enable) {
+		/*
+		 * Assert all outputs would trigger un-wanted interrupts.
+		 * Clear them before enable interrupt.
+		 */
+		STM32_EXTI_PR |= irq_mask;
+		STM32_EXTI_IMR |= irq_mask;	/* 1: unmask interrupt */
+	} else {
+		STM32_EXTI_IMR &= ~irq_mask;	/* 0: mask interrupts */
+	}
+}
+
+void keyboard_raw_gpio_interrupt(enum gpio_signal signal)
+{
+	task_wake(TASK_ID_KEYSCAN);
+}