ec/starlabs/merlin: Add support for Nuvoton EC's

Support was created for the NPCE9m5x series, using version 1.1
of the datasheet. The specific model tested was the NPCE985P/G,
on the StarLite Mk IV with version 1.00 of the EC firmware.

Signed-off-by: Sean Rhodes <sean@starlabs.systems>
Change-Id: Ib66baf1e88f5d548ce955dffa00c9b88255b2f95
Reviewed-on: https://review.coreboot.org/c/coreboot/+/62702
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Paul Menzel <paulepanter@mailbox.org>

4 files changed, 322 insertions, 7 deletions

diff --git a/src/ec/starlabs/merlin/Kconfig b/src/ec/starlabs/merlin/Kconfig
index 93101b74ec..ff6077a806 100644
--- a/src/ec/starlabs/merlin/Kconfig
+++ b/src/ec/starlabs/merlin/Kconfig
@@ -1,5 +1,11 @@
 ## SPDX-License-Identifier: GPL-2.0-only
 
+config EC_STARLABS_NUVOTON
+	bool
+	select EC_ACPI
+	help
+	  Interface to Nuvoton embedded controller principally in Star Labs notebooks.
+
 config EC_STARLABS_ITE
 	bool
 	select EC_ACPI
@@ -33,21 +39,21 @@ config EC_STARLABS_ITE_BIN_PATH
 config EC_STARLABS_KBL_LEVELS
 	bool
 	default n
-	depends on EC_STARLABS_ITE
+	depends on EC_STARLABS_ITE || EC_STARLABS_NUVOTON
 	help
 	  Select if the mainboard supports multiple levels of brightness for the keyboard.
 
 config EC_STARLABS_FAN
 	bool
 	default n
-	depends on EC_STARLABS_ITE
+	depends on EC_STARLABS_ITE || EC_STARLABS_NUVOTON
 	help
 	  Select if the mainboard has a fan.
 
 config EC_STARLABS_MAX_CHARGE
 	bool
 	default n
-	depends on EC_STARLABS_ITE
+	depends on EC_STARLABS_ITE || EC_STARLABS_NUVOTON
 	help
 	  Select if the mainboard supports limiting the maximum charge of the battery.
 
diff --git a/src/ec/starlabs/merlin/Makefile.inc b/src/ec/starlabs/merlin/Makefile.inc
index 3445ef3aa9..ac0d5e3fee 100644
--- a/src/ec/starlabs/merlin/Makefile.inc
+++ b/src/ec/starlabs/merlin/Makefile.inc
@@ -26,3 +26,12 @@ warn_no_ite_fw:
 endif
 endif
 endif
+
+ifeq ($(CONFIG_EC_STARLABS_NUVOTON),y)
+
+EC_VARIANT_DIR := $(call strip_quotes, $(CONFIG_EC_VARIANT_DIR))
+CPPFLAGS_common += -I$(src)/ec/starlabs/merlin/variants/$(EC_VARIANT_DIR)
+
+all-y += nuvoton.c
+
+endif
diff --git a/src/ec/starlabs/merlin/ec.h b/src/ec/starlabs/merlin/ec.h
index 1e7607d8fc..6a6cda5ee1 100644
--- a/src/ec/starlabs/merlin/ec.h
+++ b/src/ec/starlabs/merlin/ec.h
@@ -1,19 +1,20 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
 
 /*
- * EC communication interface for ITE Embedded Controller.
+ * EC communication interface for Embedded Controller.
  */
 
-#ifndef _EC_STARLABS_ITE_H
-#define _EC_STARLABS_ITE_H
+#ifndef _EC_STARLABS_EC_H
+#define _EC_STARLABS_EC_H
 
 /*
  * Define the expected value of the PNP base address that is fixed through
  * the BADRSEL register controlled within the EC domain by the EC Firmware.
  */
 #define ITE_FIXED_ADDR		0x4e
+#define NUVOTON_FIXED_ADDR	0x4e
 
-/* Logical device number (LDN) assignments. */
+/* Logical device number (LDN) assignments for ITE. */
 #define ITE_SP1			0x01	/* Serial Port 1 (UART) */
 #define ITE_SP2			0x02	/* Serial Port 2 (UART) */
 #define ITE_SWUC		0x04	/* System Wake-Up Control (SWUC) */
@@ -30,9 +31,21 @@
 #define ITE_PMC4		0x18	/* Power Management I/F Channel 4 (PMC4) */
 #define ITE_PMC5		0x19	/* Power Management I/F Channel 5 (PMC5) */
 
+/* Logical device number (LDN) assignments for Nuvoton. */
+#define NUVOTON_MSWC		0x04	/* Mobile System Wake-Up Control (MSWC) */
+#define NUVOTON_KBCM		0x05	/* KBC / Mouse Interface */
+#define NUVOTON_KBCK		0x06	/* KBC / Keyboard Interface */
+#define NUVOTON_SHM		0x0f	/* Shared Memory (SHM) */
+#define NUVOTON_PM1		0x11	/* Power Management I/F Channel 1 (PM1) */
+#define NUVOTON_PM2		0x12	/* Power Management I/F Channel 2 (PM2) */
+#define NUVOTON_PM3		0x17	/* Power Management I/F Channel 3 (PM3) */
+#define NUVOTON_ESHM		0x1d	/* Extended Shared Memory (ESHM) */
+#define NUVOTON_PM4		0x1e	/* Power Management I/F Channel 3 (PM4) */
+
 /* Host domain registers. */
 #define ITE_CHIPID1		0x20	/* Device ID register 1 */
 #define ITE_CHIPID2		0x21	/* Device ID register 2 */
+#define NUVOTON_CHIPID		0x27	/* Device ID register */
 
 /* EC RAM common offsets */
 #define ECRAM_MAJOR_VERSION	0x00
diff --git a/src/ec/starlabs/merlin/nuvoton.c b/src/ec/starlabs/merlin/nuvoton.c
new file mode 100644
index 0000000000..ee8a66176f
--- /dev/null
+++ b/src/ec/starlabs/merlin/nuvoton.c
@@ -0,0 +1,287 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <console/console.h>
+#include <device/device.h>
+#include <device/pnp.h>
+#include <ec/acpi/ec.h>
+#include <option.h>
+#include <pc80/keyboard.h>
+
+#include "ec.h"
+#include "ecdefs.h"
+
+uint16_t ec_get_version(void)
+{
+	return (ec_read(ECRAM_MAJOR_VERSION) << 8) | ec_read(ECRAM_MINOR_VERSION);
+}
+
+static uint8_t get_ec_value_from_option(const char *name,
+					unsigned int fallback,
+					const uint8_t *lut,
+					size_t lut_size)
+{
+	unsigned int index = get_uint_option(name, fallback);
+	if (index >= lut_size)
+		index = fallback;
+	return lut[index];
+}
+
+static uint16_t ec_get_chip_id(unsigned int port)
+{
+	return pnp_read_index(port, NUVOTON_CHIPID);
+}
+
+static void merlin_init(struct device *dev)
+{
+	if (!dev->enabled)
+		return;
+
+	/*
+	 * The address/data IO port pair for the Nuvoton EC are configurable
+	 * through the EC domain and are fixed by the EC's firmware blob. If
+	 * the value(s) passed through the "dev" structure don't match the
+	 * expected values then output severe warnings.
+	 */
+	if (dev->path.pnp.port != NUVOTON_FIXED_ADDR) {
+		printk(BIOS_ERR, "NUVOTON: Incorrect ports defined in devicetree.cb.\n");
+		printk(BIOS_ERR, "NUVOTON: Serious operational issues will arise.\n");
+		return;
+	}
+
+	const uint16_t chip_id = ec_get_chip_id(dev->path.pnp.port);
+
+	if (chip_id != NUVOTON_CHIPID_VAL) {
+		printk(BIOS_ERR, "NUVOTON: Expected chip ID 0x%04x, but got 0x%04x instead.\n",
+			NUVOTON_CHIPID_VAL, chip_id);
+		return;
+	}
+
+	pc_keyboard_init(NO_AUX_DEVICE);
+
+	/*
+	 * Restore settings from CMOS into EC RAM:
+	 *
+	 * kbl_timeout
+	 * fn_ctrl_swap
+	 * max_charge
+	 * fan_mode
+	 * fn_lock_state
+	 * trackpad_state
+	 * kbl_brightness
+	 * kbl_state
+	 */
+
+	/*
+	 * Keyboard Backlight Timeout
+	 *
+	 * Setting:	kbl_timeout
+	 *
+	 * Values:	30 Seconds, 1 Minute, 3 Minutes, 5 Minutes, Never
+	 * Default:	30 Seconds
+	 *
+	 */
+	const uint8_t kbl_timeout[] = {
+		SEC_30,
+		MIN_1,
+		MIN_3,
+		MIN_5,
+		NEVER
+	};
+
+	ec_write(ECRAM_KBL_TIMEOUT,
+		get_ec_value_from_option("kbl_timeout",
+					 0,
+					 kbl_timeout,
+					 ARRAY_SIZE(kbl_timeout)));
+
+	/*
+	 * Fn Ctrl Reverse
+	 *
+	 * Setting:	fn_ctrl_swap
+	 *
+	 * Values:	Enabled, Disabled
+	 * Default:	Disabled
+	 *
+	 */
+	const uint8_t fn_ctrl_swap[] = {
+		FN_CTRL,
+		CTRL_FN
+	};
+
+	ec_write(ECRAM_FN_CTRL_REVERSE,
+		get_ec_value_from_option("fn_ctrl_swap",
+					 1,
+					 fn_ctrl_swap,
+					 ARRAY_SIZE(fn_ctrl_swap)));
+
+	/*
+	 * Maximum Charge Level
+	 *
+	 * Setting:	max_charge
+	 *
+	 * Values:	60%, 80%, 100%
+	 * Default:	100%
+	 *
+	 */
+	const uint8_t max_charge[] = {
+		CHARGE_100,
+		CHARGE_80,
+		CHARGE_60
+	};
+
+	if (CONFIG(EC_STARLABS_MAX_CHARGE))
+		ec_write(ECRAM_MAX_CHARGE,
+			get_ec_value_from_option("max_charge",
+						 0,
+						 max_charge,
+						 ARRAY_SIZE(max_charge)));
+
+	/*
+	 * Fan Mode
+	 *
+	 * Setting:	fan_mode
+	 *
+	 * Values:	Quiet, Normal, Aggressive
+	 * Default:	Normal
+	 *
+	 */
+	const uint8_t fan_mode[] = {
+		FAN_NORMAL,
+		FAN_AGGRESSIVE,
+		FAN_QUIET
+	};
+
+	if (CONFIG(EC_STARLABS_FAN))
+		ec_write(ECRAM_FAN_MODE,
+			get_ec_value_from_option("fan_mode",
+						 0,
+						 fan_mode,
+						 ARRAY_SIZE(fan_mode)));
+
+	/*
+	 * Function Lock
+	 *
+	 * Setting:	fn_lock_state
+	 *
+	 * Values:	Locked, Unlocked
+	 * Default:	Locked
+	 *
+	 */
+	const uint8_t fn_lock_state[] = {
+		UNLOCKED,
+		LOCKED
+	};
+
+	ec_write(ECRAM_FN_LOCK_STATE,
+		get_ec_value_from_option("fn_lock_state",
+					 1,
+					 fn_lock_state,
+					 ARRAY_SIZE(fn_lock_state)));
+
+	/*
+	 * Trackpad State
+	 *
+	 * Setting:	trackpad_state
+	 *
+	 * Values:	Enabled, Disabled
+	 * Default:	Enabled
+	 *
+	 */
+	const uint8_t trackpad_state[] = {
+		TRACKPAD_ENABLED,
+		TRACKPAD_DISABLED
+	};
+
+	ec_write(ECRAM_TRACKPAD_STATE,
+		get_ec_value_from_option("trackpad_state",
+					 0,
+					 trackpad_state,
+					 ARRAY_SIZE(trackpad_state)));
+
+	/*
+	 * Keyboard Backlight Brightness
+	 *
+	 * Setting:	kbl_brightness
+	 *
+	 * Values:	Off, Low, High / Off, On
+	 * Default:	Low
+	 *
+	 */
+	const uint8_t kbl_brightness[] = {
+		KBL_ON,
+		KBL_OFF,
+		KBL_LOW,
+		KBL_HIGH
+	};
+
+	if (CONFIG(EC_STARLABS_KBL_LEVELS))
+		ec_write(ECRAM_KBL_BRIGHTNESS,
+			get_ec_value_from_option("kbl_brightness",
+						 2,
+						 kbl_brightness,
+						 ARRAY_SIZE(kbl_brightness)));
+	else
+		ec_write(ECRAM_KBL_BRIGHTNESS,
+			get_ec_value_from_option("kbl_brightness",
+						 0,
+						 kbl_brightness,
+						 ARRAY_SIZE(kbl_brightness)));
+
+	/*
+	 * Keyboard Backlight State
+	 *
+	 * Setting:	kbl_state
+	 *
+	 * Values:	Off, On
+	 * Default:	On
+	 *
+	 */
+	const uint8_t kbl_state[] = {
+		KBL_DISABLED,
+		KBL_ENABLED
+	};
+
+	ec_write(ECRAM_KBL_STATE,
+		get_ec_value_from_option("kbl_state",
+					 1,
+					 kbl_state,
+					 ARRAY_SIZE(kbl_state)));
+}
+
+static struct device_operations ops = {
+	.init		= merlin_init,
+	.read_resources	= noop_read_resources,
+	.set_resources	= noop_set_resources,
+};
+
+static struct pnp_info pnp_dev_info[] = {
+	/* System Wake-Up Control (SWUC) */
+	{ NULL,	NUVOTON_MSWC,	PNP_IO0 | PNP_IRQ0,		0xfff0,		},
+	/* KBC / Mouse Interface */
+	{ NULL, NUVOTON_KBCM,	PNP_IRQ0,					},
+	/* KBC / Keyboard Interface */
+	{ NULL, NUVOTON_KBCK,	PNP_IO0 | PNP_IO1 | PNP_IRQ0,	0x07ff,	0x07ff,	},
+	/* Shared Memory / Flash Interface (SMFI) */
+	{ NULL, NUVOTON_SHM,	PNP_IO0 | PNP_IRQ0,		0xfff0,		},
+	/* Power Management I/F Channel 1 (PMC1) */
+	{ NULL, NUVOTON_PM1,	PNP_IO0 | PNP_IO1 | PNP_IRQ0,	0x07ff,	0x07ff,	},
+	/* Power Management I/F Channel 2 (PMC2) */
+	{ NULL, NUVOTON_PM2,	PNP_IO0 | PNP_IO1 | PNP_IO2 | PNP_IRQ0,	0x07fc,
+				0x07fc, 0xfff0,					},
+	/* Power Management I/F Channel 3 (PMC3) */
+	{ NULL, NUVOTON_PM3,	PNP_IO0 | PNP_IO1 | PNP_IRQ0,	0x07ff,	0x07ff,	},
+	/* Extended Shared Memory (ESHM) */
+	{ NULL, NUVOTON_ESHM							},
+	/* Power Management I/F Channel 4 (PMC4) */
+	{ NULL, NUVOTON_PM4,	PNP_IO0 | PNP_IO1 | PNP_IRQ0,	0x07ff,	0x07ff,	},
+};
+
+static void enable_dev(struct device *dev)
+{
+	pnp_enable_devices(dev, &ops, ARRAY_SIZE(pnp_dev_info), pnp_dev_info);
+}
+
+struct chip_operations ec_starlabs_merlin_ops = {
+	CHIP_NAME("NUVOTON EC")
+	.enable_dev = enable_dev
+};