drivers: add support for pic32cx

PIC32CX is a newer debug board used on automotive platforms like
sa8797p. It uses human-readable commands over serial but speaks a
different dialect than alpaca. Add a new driver to support it and extend
available config options.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>

Author: brgl

device.h

@@ -103,6 +103,7 @@ extern const struct control_ops local_gpio_ops;
 extern const struct control_ops external_ops;
 extern const struct control_ops qcomlt_dbg_ops;
 extern const struct control_ops laurent_ops;
+extern const struct control_ops pic32cx_ops;
 
 extern const struct console_ops conmux_console_ops;
 extern const struct console_ops console_ops;

device_parser.c

@@ -172,6 +172,9 @@ static void parse_board(struct device_parser *dp)
 		} else if (!strcmp(key, "alpaca")) {
 			dev->control_dev = strdup(value);
 			set_control_ops(dev, &alpaca_ops);
+		} else if (!strcmp(key, "pic32cx")) {
+			dev->control_dev = strdup(value);
+			set_control_ops(dev, &pic32cx_ops);
 		} else if (!strcmp(key, "external")) {
 			dev->control_dev = strdup(value);
 			set_control_ops(dev, &external_ops);

drivers/pic32cx.c

@@ -0,0 +1,89 @@
+/*
+ * Copyright (c) 2026 Qualcomm Technologies, Inc. and/or its subsidiaries
+ * All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <err.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <termios.h>
+#include <unistd.h>
+
+#include "device.h"
+#include "tty.h"
+
+struct pic32cx {
+	int fd;
+	struct termios tios;
+	bool fastboot_pressed;
+};
+
+static void pic32cx_device_write(struct pic32cx *pic32cx, const char *fmt, ...)
+{
+	char buf[32];
+	va_list va;
+	int count;
+	va_start(va, fmt);
+	count = vsnprintf(buf, sizeof(buf), fmt, va);
+	va_end(va);
+
+	write(pic32cx->fd, buf, count);
+}
+
+static void pic32cx_device_power(struct pic32cx *pic32cx, int on)
+{
+	pic32cx_device_write(pic32cx, "PWR_OFF %d\r", !on);
+}
+
+static void *pic32cx_open(struct device *dev)
+{
+	struct pic32cx *pic32cx;
+
+	dev->has_power_key = true;
+
+	pic32cx = calloc(1, sizeof(*pic32cx));
+
+	pic32cx->fd = tty_open(dev->control_dev, &pic32cx->tios);
+	if (pic32cx->fd < 0)
+		err(1, "failed to open %s", dev->control_dev);
+
+	pic32cx_device_power(pic32cx, 1);
+
+	sleep(5);
+
+	return pic32cx;
+}
+
+static int pic32cx_power(struct device *dev, bool on)
+{
+	pic32cx_device_power(dev->cdb, on);
+
+	return 0;
+}
+
+static void pic32cx_key(struct device *dev, int key, bool asserted)
+{
+	struct pic32cx *pic32cx = dev->cdb;
+
+	switch (key) {
+	case DEVICE_KEY_FASTBOOT:
+		if (asserted)
+			pic32cx->fastboot_pressed = true;
+		if (!asserted && pic32cx->fastboot_pressed) {
+			pic32cx_device_write(pic32cx, "MD_FASTBOOT\r");
+			pic32cx->fastboot_pressed = false;
+		}
+		break;
+	}
+}
+
+const struct control_ops pic32cx_ops = {
+	.open = pic32cx_open,
+	.power = pic32cx_power,
+	.key = pic32cx_key,
+};

meson.build

@@ -72,6 +72,7 @@ drivers_srcs = ['drivers/alpaca.c',
 		'drivers/ftdi-gpio.c',
 		'drivers/laurent.c',
 		'drivers/local-gpio.c',
+		'drivers/pic32cx.c',
 		'drivers/qcomlt_dbg.c',
 		]
 

schema.yaml

@@ -85,6 +85,10 @@ properties:
           description: Alpaca board control device path
           $ref: "#/$defs/device_path"
 
+        pic32cx:
+          description: PIC32CX board control device path
+          $ref: "#/$defs/device_path"
+
         users:
           description: User access allowance for the board
           type: array