zephyr: Shim nct38xx io expander alert

Zephyr upstream added NCT38XX GPIO support except for TCPC
functionality. The NCT38XX GPIO & TCPC share the same alert pin. The
alert should be handled at the same position.

This CL adds nct38xx_get_gpio_device_from_port() for Cros NCT38XX alert
handler. It can connect Cros TCPC alert & Zephyr NCT38XX GPIO alter
handler. So we can process the GPIO & TCPC alert at Cros task. The
following is the TCPC binding example:
usbc {
	compatible = "named-usbc-ports";
	#address-cells = <1>;
	#size-cells = <0>;
	port0: usbc-port@0 {
		reg = <0>;
		tcpc {
			compatible = "nuvoton,nct38xx";
			gpio-dev = <&nct3807_gpio>;
		};
	};
};

BUG=b:203672150
BRANCH=none
TEST=test GPIO interrupt on NCT38XX

Cq-Depend: chromium:3297249
Signed-off-by: Wealian Liao <whliao@nuvoton.corp-partner.google.com>
Change-Id: Iec355ccb581590d24cc9fcc809449b3654014a40
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/3271801
Reviewed-by: Keith Short <keithshort@chromium.org>
Reviewed-by: Jack Rosenthal <jrosenth@chromium.org>
Commit-Queue: Keith Short <keithshort@chromium.org>

5 files changed, 106 insertions, 7 deletions

diff --git a/driver/tcpm/nct38xx.c b/driver/tcpm/nct38xx.c
index 00240516e5..0d45c8aa9f 100644
--- a/driver/tcpm/nct38xx.c
+++ b/driver/tcpm/nct38xx.c
@@ -14,6 +14,17 @@
 #include "tcpm/tcpci.h"
 #include "usb_common.h"
 
+#ifdef CONFIG_ZEPHYR
+#include <device.h>
+#include <drivers/gpio/gpio_nct38xx.h>
+#include "usbc/tcpc_nct38xx.h"
+#endif
+
+#if defined(CONFIG_ZEPHYR) && defined(CONFIG_IO_EXPANDER_NCT38XX)
+#error CONFIG_IO_EXPANDER_NCT38XX cannot be used with Zephyr.
+#error Enable the Zephyr driver CONFIG_GPIO_NCT38XX instead.
+#endif
+
 #if !defined(CONFIG_USB_PD_TCPM_TCPCI)
 #error "NCT38XX is using part of standard TCPCI control"
 #error "Please upgrade your board configuration"
@@ -134,8 +145,19 @@ static int nct38xx_init(int port)
 	 * Enable the Vendor Define alert event only when the IO expander
 	 * feature is defined
 	 */
-	if (IS_ENABLED(CONFIG_IO_EXPANDER_NCT38XX))
+	if (IS_ENABLED(CONFIG_IO_EXPANDER_NCT38XX) ||
+	    IS_ENABLED(CONFIG_GPIO_NCT38XX)) {
+#ifdef CONFIG_ZEPHYR
+		const struct device *dev =
+			nct38xx_get_gpio_device_from_port(port);
+
+		if (!device_is_ready(dev)) {
+			CPRINTS("C%d: device is not ready", port);
+			return EC_ERROR_BUSY;
+		}
+#endif /* CONFIG_ZEPHYR */
 		reg |= TCPC_REG_ALERT_VENDOR_DEF;
+	}
 
 	rv = tcpc_update16(port,
 			   TCPC_REG_ALERT_MASK,
@@ -244,6 +266,20 @@ __overridable int board_map_nct38xx_tcpc_port_to_ioex(int port)
 	return port;
 }
 
+static inline void nct38xx_tcpc_vendor_defined_alert(int port)
+{
+#ifdef CONFIG_ZEPHYR
+	const struct device *dev = nct38xx_get_gpio_device_from_port(port);
+
+	nct38xx_gpio_alert_handler(dev);
+#else
+	int ioexport;
+
+	ioexport = board_map_nct38xx_tcpc_port_to_ioex(port);
+	nct38xx_ioex_event_handler(ioexport);
+#endif /* CONFIG_ZEPHYR */
+}
+
 static void nct38xx_tcpc_alert(int port)
 {
 	int alert, rv;
@@ -274,12 +310,10 @@ static void nct38xx_tcpc_alert(int port)
 	 * tcpci_tcpc_alert().  Check the Vendor Defined Alert bit to
 	 * handle the IOEX IO's interrupt event.
 	 */
-	if (IS_ENABLED(CONFIG_IO_EXPANDER_NCT38XX) &&
-		rv == EC_SUCCESS && (alert & TCPC_REG_ALERT_VENDOR_DEF)) {
-		int ioexport;
-
-		ioexport = board_map_nct38xx_tcpc_port_to_ioex(port);
-		nct38xx_ioex_event_handler(ioexport);
+	if ((IS_ENABLED(CONFIG_IO_EXPANDER_NCT38XX) ||
+	     IS_ENABLED(CONFIG_GPIO_NCT38XX)) &&
+	    rv == EC_SUCCESS && (alert & TCPC_REG_ALERT_VENDOR_DEF)) {
+		nct38xx_tcpc_vendor_defined_alert(port);
 	}
 }
 
diff --git a/zephyr/dts/bindings/usbc/nuvoton,nct38xx.yaml b/zephyr/dts/bindings/usbc/nuvoton,nct38xx.yaml
new file mode 100644
index 0000000000..2d85d14f79
--- /dev/null
+++ b/zephyr/dts/bindings/usbc/nuvoton,nct38xx.yaml
@@ -0,0 +1,14 @@
+# Copyright 2021 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.
+
+description: Nuvoton NCT38XX USB TCPC binding
+
+compatible: "nuvoton,nct38xx"
+
+properties:
+  gpio-dev:
+    type: phandle
+    description: |
+      Pointer to the NCT38XX GPIO device. This is used to binding the Cros TCPC
+      port index to Zephyr NCT38XX GPIO device.
diff --git a/zephyr/shim/include/usbc/tcpc_nct38xx.h b/zephyr/shim/include/usbc/tcpc_nct38xx.h
new file mode 100644
index 0000000000..fa60d1caa9
--- /dev/null
+++ b/zephyr/shim/include/usbc/tcpc_nct38xx.h
@@ -0,0 +1,18 @@
+/* Copyright 2021 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.
+ */
+
+#ifndef __CROS_EC_TCPC_NCT38XX_H
+#define __CROS_EC_TCPC_NCT38XX_H
+
+/**
+ * @brief Get the NCT38XX GPIO device from the TCPC port enumeration
+ *
+ * @param port The enumeration of TCPC port
+ *
+ * @return NULL if failed, otherwise a pointer to NCT38XX GPIO device
+ */
+const struct device *nct38xx_get_gpio_device_from_port(const int port);
+
+#endif /* __CROS_EC_TCPC_NCT38XX_H */
diff --git a/zephyr/shim/src/CMakeLists.txt b/zephyr/shim/src/CMakeLists.txt
index 0c795f6b9b..fe9a5a015d 100644
--- a/zephyr/shim/src/CMakeLists.txt
+++ b/zephyr/shim/src/CMakeLists.txt
@@ -53,3 +53,5 @@ zephyr_library_sources_ifdef(CONFIG_PLATFORM_EC_WATCHDOG    watchdog.c)
 zephyr_library_sources_ifdef(CONFIG_PLATFORM_EC_BC12_DETECT_PI3USB9201
 	                                                     bc12_pi3usb9201.c)
 zephyr_library_sources_ifdef(CONFIG_PLATFORM_EC_USBC_PPC    ppc.c)
+zephyr_library_sources_ifdef(CONFIG_PLATFORM_EC_USB_PD_TCPM_NCT38XX
+                                                            tcpc_nct38xx.c)
diff --git a/zephyr/shim/src/tcpc_nct38xx.c b/zephyr/shim/src/tcpc_nct38xx.c
new file mode 100644
index 0000000000..d18e4ccbbe
--- /dev/null
+++ b/zephyr/shim/src/tcpc_nct38xx.c
@@ -0,0 +1,31 @@
+/* Copyright 2021 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.
+ */
+
+#include <device.h>
+#include <devicetree.h>
+
+#include "config.h"
+#include "usbc/tcpc_nct38xx.h"
+
+#define TCPC_PORT(id) DT_REG_ADDR(DT_PARENT(id))
+
+#define GPIO_DEV_WITH_COMMA(id) DEVICE_DT_GET(DT_PHANDLE(id, gpio_dev)),
+
+#define GPIO_DEV_BINDING(id)                        \
+	COND_CODE_1(DT_NODE_HAS_PROP(id, gpio_dev), \
+		    ([TCPC_PORT(id)] = GPIO_DEV_WITH_COMMA(id)), ())
+
+/* NCT38XX GPIO device pool for binding the TCPC port and NCT38XX GPIO device */
+static const struct device
+	*nct38xx_gpio_devices[CONFIG_PLATFORM_EC_USB_PD_PORT_MAX_COUNT] = {
+		DT_FOREACH_STATUS_OKAY(nuvoton_nct38xx, GPIO_DEV_BINDING)
+	};
+
+const struct device *nct38xx_get_gpio_device_from_port(const int port)
+{
+	if (port < 0 || port >= CONFIG_PLATFORM_EC_USB_PD_PORT_MAX_COUNT)
+		return NULL;
+	return nct38xx_gpio_devices[port];
+}