drivers: add NPCX7 cros_kb_raw driver

NPCX keyboard scanning module is supported by up to 18 open-drain
output signals and 8 input signals. Switch-based keyboard matrices are
supported by Schmitt trigger inputs that have internal pull-up
resistors. For power efficiency, the inputs include interrupt and
wake-up capability so that pressing/releasing keys can be identified
without scanning the keyboard matrix in either Active, Sleep or Deep
Sleep power state.

The CL also includes:
— Add npcx cros_kb_raw device tree declarations.
— cros_kb_raw api implementations
- Enable Volteer keyboard scan task

BRANCH=none
BUG=b:167405015, b:172676906
TEST=build pass by zmake configure -B ./build projects/experimental/volteer.
TEST=check all the keys on volteer platform by "ksstate".

Change-Id: I1cbdaa0e81cbb4447daede82774711f4d50f613d
Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Wealian Liao <whliao@nuvoton.corp-partner.google.com>
Signed-off-by: Mulin Chao <MLChao@nuvoton.com>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/zephyr-chrome/+/2523940
Commit-Queue: Jack Rosenthal <jrosenth@chromium.org>
Reviewed-by: Yuval Peress <peress@chromium.org>
Reviewed-by: Jett Rink <jettrink@chromium.org>
Reviewed-by: Jack Rosenthal <jrosenth@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2630148
Tested-by: Jack Rosenthal <jrosenth@chromium.org>

3 files changed, 237 insertions, 0 deletions

diff --git a/zephyr/include/drivers/cros_kb_raw.h b/zephyr/include/drivers/cros_kb_raw.h
new file mode 100644
index 0000000000..1724f59d95
--- /dev/null
+++ b/zephyr/include/drivers/cros_kb_raw.h
@@ -0,0 +1,169 @@
+/*
+ * Copyright 2020 Google LLC
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/**
+ * @file
+ * @brief Chrome OS-specific API for raw keyboard access
+ * This exists only support the interface expected by the Chrome OS EC. It seems
+ * better to implement this so we can make use of most of the existing code in
+ * its keyboard_scan.c file and thus make sure we operate the same way.
+ *
+ * It provides raw access to keyboard GPIOs.
+ *
+ * The keyboard matrix is read (by the caller, keyboard_scan.c in ECOS) by
+ * driving output signals on the column lines and reading the row lines.
+ *
+ * This API and any drivers should be removed once we can safely move to using
+ * the Zephyr kscan API.
+ */
+
+#ifndef ZEPHYR_INCLUDE_DRIVERS_CROS_KB_RAW_H_
+#define ZEPHYR_INCLUDE_DRIVERS_CROS_KB_RAW_H_
+
+#include <kernel.h>
+#include <device.h>
+
+/**
+ * @brief CROS Keyboard Raw Driver APIs
+ * @defgroup cros_kb_raw_interface CROS Keyboard Raw Driver APIs
+ * @ingroup io_interfaces
+ * @{
+ */
+
+/**
+ * @cond INTERNAL_HIDDEN
+ *
+ * cros keyboard raw driver API definition and system call entry points
+ *
+ * (Internal use only.)
+ */
+typedef int (*cros_kb_raw_api_init)(const struct device *dev);
+
+typedef int (*cros_kb_raw_api_drive_column)(const struct device *dev, int col);
+
+typedef int (*cros_kb_raw_api_read_rows)(const struct device *dev);
+
+typedef int (*cros_kb_raw_api_enable_interrupt)(const struct device *dev,
+						int enable);
+
+__subsystem struct cros_kb_raw_driver_api {
+	cros_kb_raw_api_init init;
+	cros_kb_raw_api_drive_column drive_colum;
+	cros_kb_raw_api_read_rows read_rows;
+	cros_kb_raw_api_enable_interrupt enable_interrupt;
+};
+
+/**
+ * @endcond
+ */
+
+/**
+ * @brief Initialize the raw keyboard interface.
+ *
+ * Must be called before any other functions in this interface.
+ *
+ * @param dev Pointer to the device structure for the keyboard driver instance.
+ *
+ * @return 0 If successful.
+ * @retval -ENOTSUP Not supported api function.
+ */
+__syscall int cros_kb_raw_init(const struct device *dev);
+
+static inline int z_impl_cros_kb_raw_init(const struct device *dev)
+{
+	const struct cros_kb_raw_driver_api *api =
+		(const struct cros_kb_raw_driver_api *)dev->api;
+
+	if (!api->init) {
+		return -ENOTSUP;
+	}
+
+	return api->init(dev);
+}
+
+/**
+ * @brief Drive the specified column low.
+ *
+ * Other columns are tristated.  See enum keyboard_column_index for special
+ * values for <col>.
+ *
+ * @param dev Pointer to the device structure for the keyboard driver instance.
+ * @param col Specified column is driven to low.
+ *
+ * @return 0 If successful.
+ * @retval -ENOTSUP Not supported api function.
+ */
+__syscall int cros_kb_raw_drive_column(const struct device *dev, int col);
+static inline int z_impl_cros_kb_raw_drive_column(const struct device *dev,
+						  int col)
+{
+	const struct cros_kb_raw_driver_api *api =
+		(const struct cros_kb_raw_driver_api *)dev->api;
+
+	if (!api->drive_colum) {
+		return -ENOTSUP;
+	}
+
+	return api->drive_colum(dev, col);
+}
+
+/**
+ * @brief Read raw row state.
+ *
+ * Bits are 1 if signal is present, 0 if not present.
+ *
+ * @param dev Pointer to the device structure for the keyboard driver instance.
+ *
+ * @return current raw row state value.
+ */
+__syscall int cros_kb_raw_read_rows(const struct device *dev);
+static inline int z_impl_cros_kb_raw_read_rows(const struct device *dev)
+{
+	const struct cros_kb_raw_driver_api *api =
+		(const struct cros_kb_raw_driver_api *)dev->api;
+
+	if (!api->read_rows) {
+		return 0;
+	}
+
+	return api->read_rows(dev);
+}
+
+/**
+ * @brief Enable or disable keyboard interrupts.
+ *
+ * Enabling interrupts will clear any pending interrupt bits.  To avoid missing
+ * any interrupts that occur between the end of scanning and then, you should
+ * call cros_kb_raw_read_rows() after this.  If it returns non-zero, disable
+ * interrupts and go back to polling mode instead of waiting for an interrupt.
+ *
+ * @param dev Pointer to the device structure for the keyboard driver instance.
+ * @param enable If 1, enable keyboard interrupt. Otherwise, disable it.
+ *
+ * @return 0 If successful.
+ * @retval -ENOTSUP Not supported api function.
+ */
+__syscall int cros_kb_raw_enable_interrupt(const struct device *dev,
+					   int enable);
+
+static inline int z_impl_cros_kb_raw_enable_interrupt(const struct device *dev,
+						      int enable)
+{
+	const struct cros_kb_raw_driver_api *api =
+		(const struct cros_kb_raw_driver_api *)dev->api;
+
+	if (!api->enable_interrupt) {
+		return -ENOTSUP;
+	}
+
+	return api->enable_interrupt(dev, enable);
+}
+
+/**
+ * @}
+ */
+#include <syscalls/cros_kb_raw.h>
+#endif /* ZEPHYR_INCLUDE_DRIVERS_CROS_KB_RAW_H_ */
diff --git a/zephyr/include/dt-bindings/cros-kb-raw/npcx_cros_kb_raw.h b/zephyr/include/dt-bindings/cros-kb-raw/npcx_cros_kb_raw.h
new file mode 100644
index 0000000000..f979ae8481
--- /dev/null
+++ b/zephyr/include/dt-bindings/cros-kb-raw/npcx_cros_kb_raw.h
@@ -0,0 +1,9 @@
+/*
+ * Copyright 2020 Google LLC
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+#ifndef ZEPHYR_INCLUDE_DT_BINDINGS_CROS_KB_RAW_NPCX_CROS_KB_RAW_H_
+#define ZEPHYR_INCLUDE_DT_BINDINGS_CROS_KB_RAW_NPCX_CROS_KB_RAW_H_
+
+#endif /* ZEPHYR_INCLUDE_DT_BINDINGS_CROS_KB_RAW_NPCX_CROS_KB_RAW_H_ */
diff --git a/zephyr/include/soc/nuvoton_npcx/reg_def_cros.h b/zephyr/include/soc/nuvoton_npcx/reg_def_cros.h
new file mode 100644
index 0000000000..022c58fc24
--- /dev/null
+++ b/zephyr/include/soc/nuvoton_npcx/reg_def_cros.h
@@ -0,0 +1,59 @@
+/*
+ * Copyright (c) 2020 Nuvoton Technology Corporation.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/*
+ * @file
+ * @brief Nuvoton NPCX register structure definitions used by the Chrome OS EC.
+ */
+
+#ifndef _NUVOTON_NPCX_REG_DEF_CROS_H
+#define _NUVOTON_NPCX_REG_DEF_CROS_H
+
+/*
+ * KBS (Keyboard Scan) device registers
+ */
+struct kbs_reg {
+	volatile uint8_t reserved1[4];
+	/* 0x004: Keyboard Scan In */
+	volatile uint8_t KBSIN;
+	/* 0x005: Keyboard Scan In Pull-Up Enable */
+	volatile uint8_t KBSINPU;
+	/* 0x006: Keyboard Scan Out 0 */
+	volatile uint16_t KBSOUT0;
+	/* 0x008: Keyboard Scan Out 1 */
+	volatile uint16_t KBSOUT1;
+	/* 0x00A: Keyboard Scan Buffer Index */
+	volatile uint8_t KBS_BUF_INDX;
+	/* 0x00B: Keyboard Scan Buffer Data */
+	volatile uint8_t KBS_BUF_DATA;
+	/* 0x00C: Keyboard Scan Event */
+	volatile uint8_t KBSEVT;
+	/* 0x00D: Keyboard Scan Control */
+	volatile uint8_t KBSCTL;
+	/* 0x00E: Keyboard Scan Configuration Index */
+	volatile uint8_t KBS_CFG_INDX;
+	/* 0x00F: Keyboard Scan Configuration Data */
+	volatile uint8_t KBS_CFG_DATA;
+};
+
+/* KBS register fields */
+#define NPCX_KBSBUFINDX                  0
+#define NPCX_KBSEVT_KBSDONE              0
+#define NPCX_KBSEVT_KBSERR               1
+#define NPCX_KBSCTL_START                0
+#define NPCX_KBSCTL_KBSMODE              1
+#define NPCX_KBSCTL_KBSIEN               2
+#define NPCX_KBSCTL_KBSINC               3
+#define NPCX_KBSCTL_KBHDRV_FIELD         FIELD(6, 2)
+#define NPCX_KBSCFGINDX                  0
+/* Index of 'Automatic Scan' configuration register */
+#define KBS_CFG_INDX_DLY1                0 /* Keyboard Scan Delay T1 Byte */
+#define KBS_CFG_INDX_DLY2                1 /* Keyboard Scan Delay T2 Byte */
+#define KBS_CFG_INDX_RTYTO               2 /* Keyboard Scan Retry Timeout */
+#define KBS_CFG_INDX_CNUM                3 /* Keyboard Scan Columns Number */
+#define KBS_CFG_INDX_CDIV                4 /* Keyboard Scan Clock Divisor */
+
+#endif /* _NUVOTON_NPCX_REG_DEF_CROS_H */