Add local gpio control

This driver permits controlling local (on the system) gpios
by using the libgpiod library.

Support for gpiod v1 and v2 is added, and parses the options
via the yaml parser.

This can be tested with the gpio-sim module:
https://docs.kernel.org/admin-guide/gpio/gpio-sim.html

Signed-off-by: Neil Armstrong <[email protected]>

README

@@ -61,3 +61,26 @@ devices:
     fastboot: 91671140
     fastboot_set_active: true
     fastboot_key_timeout: 2
+
+  - board: testboard
+    console: /dev/serial/by-id/usb-1234-if00-port0
+    name: GPIO controller board
+    local_gpio:
+      - power:
+          chip: gpiochip0
+          line: 7
+          active_low: true
+      - fastboot_key:
+          chip: gpiochip0
+          line: 8
+          active_low: true
+      - power_key:
+          chip: gpiochip0
+          line: 14
+          active_low: true
+      - usb_disconnect:
+          chip: gpiochip1
+          line: 4
+    fastboot: cacafada
+    fastboot_set_active: true
+    fastboot_key_timeout: 2

ci/archlinux.sh

@@ -20,6 +20,7 @@ pacman -Syu --noconfirm \
 	libftdi-compat \
 	libyaml \
 	systemd-libs \
+	libgpiod \
 	pkgconf \
 	meson \
 	$PKGS_CC

ci/debian.cross-compile.sh

@@ -22,6 +22,7 @@ apt install -y --no-install-recommends \
 	libftdi-dev:${ARCH} \
 	libudev-dev:${ARCH} \
 	libyaml-dev:${ARCH} \
+	libgpiod-dev:${ARCH} \
 	gcc-`dpkg-architecture -a ${ARCH} -q DEB_TARGET_GNU_TYPE`
 
 echo "Install finished: $0"

ci/debian.i386.sh

@@ -23,6 +23,7 @@ apt install -y --no-install-recommends \
 	libftdi-dev:i386 \
 	libudev-dev:i386 \
 	libyaml-dev:i386 \
+	libgpiod-dev:i386 \
 	$PKGS_CC
 
 echo "Install finished: $0"

ci/debian.sh

@@ -32,6 +32,7 @@ apt install -y --no-install-recommends \
 	libftdi-dev \
 	libudev-dev \
 	libyaml-dev \
+	libgpiod-dev \
 	meson \
 	$PKGS_CC
 

ci/fedora.sh

@@ -20,6 +20,7 @@ dnf -y install \
 	libftdi-devel \
 	libudev-devel \
 	libyaml-devel \
+	libgpiod-devel \
 	meson \
 	$PKGS_CC
 

device.h

@@ -93,6 +93,7 @@ extern const struct control_ops alpaca_ops;
 extern const struct control_ops cdb_assist_ops;
 extern const struct control_ops conmux_ops;
 extern const struct control_ops ftdi_gpio_ops;
+extern const struct control_ops local_gpio_ops;
 extern const struct control_ops external_ops;
 extern const struct control_ops qcomlt_dbg_ops;
 

device_parser.c

@@ -129,6 +129,13 @@ static void parse_board(struct device_parser *dp)
 			continue;
 		}
 
+		if (!strcmp(key, "local_gpio")) {
+			dev->control_options = local_gpio_ops.parse_options(dp);
+			if (dev->control_options)
+				set_control_ops(dev, &local_gpio_ops);
+			continue;
+		}
+
 		device_parser_expect(dp, YAML_SCALAR_EVENT, value, TOKEN_LENGTH);
 
 		if (!strcmp(key, "board")) {

local-gpio-v1.c

@@ -0,0 +1,94 @@
+/*
+ * Copyright (c) 2023, Linaro Ltd.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ *
+ * 3. Neither the name of the copyright holder nor the names of its contributors
+ * may be used to endorse or promote products derived from this software without
+ * specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+#include <ctype.h>
+#include <err.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <stdbool.h>
+
+/* local-gpio implementation for libgpiod major version 1 */
+
+#include "local-gpio.h"
+
+#include <gpiod.h>
+
+int local_gpio_init(struct local_gpio *local_gpio)
+{
+	int i;
+
+	for (i = 0; i < GPIO_COUNT; ++i) {
+		struct gpiod_line_request_config cfg;
+
+		if (!local_gpio->options->gpios[i].present)
+			continue;
+
+		local_gpio->gpios[i].chip =
+			gpiod_chip_open_lookup(local_gpio->options->gpios[i].chip);
+		if (!local_gpio->gpios[i].chip) {
+			err(1, "Unable to open gpiochip '%s'",
+			    local_gpio->options->gpios[i].chip);
+			return -1;
+		}
+
+		cfg.consumer = "cdba";
+		cfg.request_type = GPIOD_LINE_REQUEST_DIRECTION_OUTPUT;
+		cfg.flags = 0;
+
+		if (local_gpio->options->gpios[i].active_low)
+			cfg.flags = GPIOD_LINE_REQUEST_FLAG_ACTIVE_LOW;
+
+		local_gpio->gpios[i].line = gpiod_chip_get_line(local_gpio->gpios[i].chip,
+							local_gpio->options->gpios[i].offset);
+
+		if (!local_gpio->gpios[i].line) {
+			err(1, "Unable to find gpio %d offset %u",
+			    i, local_gpio->options->gpios[i].offset);
+			return -1;
+		}
+
+		if (gpiod_line_request(local_gpio->gpios[i].line, &cfg, 0))  {
+			err(1, "Unable to request gpio %d offset %u",
+			    i, local_gpio->options->gpios[i].offset);
+			return -1;
+		}
+	}
+
+	return 0;
+}
+
+int local_gpio_set_value(struct local_gpio *local_gpio, unsigned int gpio, bool on)
+{
+	return gpiod_line_set_value(local_gpio->gpios[gpio].line, on);
+}

local-gpio-v2.c

@@ -0,0 +1,128 @@
+/*
+ * Copyright (c) 2023, Linaro Ltd.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ *
+ * 3. Neither the name of the copyright holder nor the names of its contributors
+ * may be used to endorse or promote products derived from this software without
+ * specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+#define _GNU_SOURCE
+#include <ctype.h>
+#include <err.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <stdbool.h>
+
+/* local-gpio implementation for libgpiod major version 2 */
+
+#include "local-gpio.h"
+
+#include <gpiod.h>
+
+int local_gpio_init(struct local_gpio *local_gpio)
+{
+	struct gpiod_request_config *req_cfg;
+	int i;
+
+	req_cfg = gpiod_request_config_new();
+	if (!req_cfg) {
+		err(1, "Unable to allocate request config");
+		return -1;
+	}
+	gpiod_request_config_set_consumer(req_cfg, "cdba");
+
+	for (i = 0; i < GPIO_COUNT; ++i) {
+		struct gpiod_line_settings *line_settings;
+		struct gpiod_line_config *line_cfg;
+		char *gpiochip_path;
+
+		if (!local_gpio->options->gpios[i].present)
+			continue;
+
+		if (asprintf(&gpiochip_path, "/dev/%s", local_gpio->options->gpios[i].chip) < 0) {
+			free(local_gpio);
+			return -1;
+		}
+
+		local_gpio->gpios[i].chip = gpiod_chip_open(gpiochip_path);
+		if (!local_gpio->gpios[i].chip) {
+			err(1, "Unable to open gpiochip '%s'", local_gpio->options->gpios[i].chip);
+			return -1;
+		}
+
+		line_settings = gpiod_line_settings_new();
+		if (!line_settings) {
+			err(1, "Unable to allocate gpio line settings");
+			return -1;
+		}
+		if (gpiod_line_settings_set_direction(line_settings,
+						      GPIOD_LINE_DIRECTION_OUTPUT) < 0) {
+			err(1, "Unable to set line direction");
+			return -1;
+		}
+		if (local_gpio->options->gpios[i].active_low)
+			gpiod_line_settings_set_active_low(line_settings, true);
+		if (gpiod_line_settings_set_output_value(line_settings,
+							 GPIOD_LINE_VALUE_INACTIVE) < 0) {
+			err(1, "Unable to set line output value");
+			return -1;
+		}
+
+		line_cfg = gpiod_line_config_new();
+		if (!line_cfg) {
+			err(1, "Unable to allocate gpio line settings");
+			return -1;
+		}
+		if (gpiod_line_config_add_line_settings(line_cfg,
+							&local_gpio->options->gpios[i].offset, 1,
+							line_settings) < 0) {
+			err(1, "Unable to set line config");
+			return -1;
+		}
+
+		local_gpio->gpios[i].line = gpiod_chip_request_lines(local_gpio->gpios[i].chip,
+								     req_cfg, line_cfg);
+
+		if (!local_gpio->gpios[i].line) {
+			err(1, "Unable to request gpio %d offset %u",
+			    i, local_gpio->options->gpios[i].offset);
+			return -1;
+		}
+	}
+
+	return 0;
+}
+
+int local_gpio_set_value(struct local_gpio *local_gpio, unsigned int gpio, bool on)
+{
+	return gpiod_line_request_set_value(local_gpio->gpios[gpio].line,
+					    local_gpio->options->gpios[gpio].offset,
+					    on ? GPIOD_LINE_VALUE_ACTIVE
+					       : GPIOD_LINE_VALUE_INACTIVE);
+}