Merge tag 'gpio-v5.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio

Pull GPIO updates from Linus Walleij:
 "This is the bulk of GPIO development for the v5.7 kernel cycle.

  Core and userspace API:

   - The userspace API KFIFOs have been imoproved with locks that do not
     block interrupts. This makes us better at getting events to
     userspace without blocking or disturbing new events arriving in the
     same time. This was reviewed by the KFIFO maintainer Stefani. This
     is a generic improvement which paves the road for similar
     improvements in other subsystems.

   - We provide a new ioctl() for monitoring changes in the line
     information, such as when multiple clients are taking lines and
     giving them back, possibly reconfiguring them in the process: we
     can now monitor that and not get stuck with stale static
     information.

   - An example tool 'gpio-watch' is provided to showcase this
     functionality.

   - Timestamps for events are switched to ktime_get_ns() which is
     monotonic. We previously had a 'realtime' stamp which could move
     forward and *backward* in time, which probably would just cause
     silent bugs and weird behaviour. In the long run we see two
     relevant timestamps: ktime_get_ns() or the timestamp sometimes
     provided by the GPIO hardware itself, if that exists.

   - Device Tree overlay support for GPIO hogs. On systems that load
     overlays, these overlays can now contain hogs, and will then be
     respected.

   - Handle pin control interaction with nonexisting pin ranges in the
     GPIO library core instead of in the individual drivers.

  New drivers:

   - New driver for the Mellanox BlueField 2 GPIO controller.

  Driver improvements:

   - Introduce the BGPIOF_NO_SET_ON_INPUT flag to the generic MMIO GPIO
     library and use this flag in the MT7621 driver.

   - Texas Instruments OMAP CPU power management improvements, such as
     blocking of idle on pending GPIO interrupts"

* tag 'gpio-v5.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (59 commits)
  Revert "gpio: eic-sprd: Use devm_platform_ioremap_resource()"
  pinctrl: Unconditionally assign .request()/.free()
  gpio: Unconditionally assign .request()/.free()
  gpio: export of_pinctrl_get to modules
  pinctrl: Define of_pinctrl_get() dummy for !PINCTRL
  gpio: Rename variable in core APIs
  gpio: Avoid using pin ranges with !PINCTRL
  gpiolib: Remove unused gpio_chip parameter from gpio_set_bias()
  gpiolib: Pass gpio_desc to gpio_set_config()
  gpiolib: Introduce gpiod_set_config()
  tools: gpio: Fix out-of-tree build regression
  gpio: gpiolib: fix a doc warning
  gpio: tegra186: Add Tegra194 pin ranges for GG.0 and GG.1
  gpio: tegra186: Add support for pin ranges
  gpio: Support GPIO controllers without pin-ranges
  ARM: integrator: impd1: Use GPIO_LOOKUP() helper macro
  gpio: brcmstb: support gpio-line-names property
  tools: gpio: Fix typo in gpio-utils
  tools: gpio-hammer: Apply scripts/Lindent and retain good changes
  gpiolib: gpio_name_to_desc: factor out !name check
  ...

6 files changed, 132 insertions, 7 deletions

diff --git a/tools/gpio/.gitignore b/tools/gpio/.gitignore
index d0a66c48865c..a00d604027a2 100644
--- a/tools/gpio/.gitignore
+++ b/tools/gpio/.gitignore
@@ -1,5 +1,6 @@
 # SPDX-License-Identifier: GPL-2.0-only
 gpio-event-mon
 gpio-hammer
+gpio-watch
 lsgpio
 include/linux/gpio.h
diff --git a/tools/gpio/Build b/tools/gpio/Build
index 4141f35837db..67c7b7f6a717 100644
--- a/tools/gpio/Build
+++ b/tools/gpio/Build
@@ -2,3 +2,4 @@ gpio-utils-y += gpio-utils.o
 lsgpio-y += lsgpio.o gpio-utils.o
 gpio-hammer-y += gpio-hammer.o gpio-utils.o
 gpio-event-mon-y += gpio-event-mon.o gpio-utils.o
+gpio-watch-y += gpio-watch.o
diff --git a/tools/gpio/Makefile b/tools/gpio/Makefile
index 6080de58861f..440434027557 100644
--- a/tools/gpio/Makefile
+++ b/tools/gpio/Makefile
@@ -18,7 +18,7 @@ MAKEFLAGS += -r
 
 override CFLAGS += -O2 -Wall -g -D_GNU_SOURCE -I$(OUTPUT)include
 
-ALL_TARGETS := lsgpio gpio-hammer gpio-event-mon
+ALL_TARGETS := lsgpio gpio-hammer gpio-event-mon gpio-watch
 ALL_PROGRAMS := $(patsubst %,$(OUTPUT)%,$(ALL_TARGETS))
 
 all: $(ALL_PROGRAMS)
@@ -35,7 +35,7 @@ $(OUTPUT)include/linux/gpio.h: ../../include/uapi/linux/gpio.h
 
 prepare: $(OUTPUT)include/linux/gpio.h
 
-GPIO_UTILS_IN := $(output)gpio-utils-in.o
+GPIO_UTILS_IN := $(OUTPUT)gpio-utils-in.o
 $(GPIO_UTILS_IN): prepare FORCE
 	$(Q)$(MAKE) $(build)=gpio-utils
 
@@ -66,6 +66,15 @@ $(GPIO_EVENT_MON_IN): prepare FORCE $(OUTPUT)gpio-utils-in.o
 $(OUTPUT)gpio-event-mon: $(GPIO_EVENT_MON_IN)
 	$(QUIET_LINK)$(CC) $(CFLAGS) $(LDFLAGS) $< -o $@
 
+#
+# gpio-watch
+#
+GPIO_WATCH_IN := $(OUTPUT)gpio-watch-in.o
+$(GPIO_WATCH_IN): prepare FORCE
+	$(Q)$(MAKE) $(build)=gpio-watch
+$(OUTPUT)gpio-watch: $(GPIO_WATCH_IN)
+	$(QUIET_LINK)$(CC) $(CFLAGS) $(LDFLAGS) $< -o $@
+
 clean:
 	rm -f $(ALL_PROGRAMS)
 	rm -f $(OUTPUT)include/linux/gpio.h
diff --git a/tools/gpio/gpio-hammer.c b/tools/gpio/gpio-hammer.c
index 0e0060a6eb34..9fd926e8cb52 100644
--- a/tools/gpio/gpio-hammer.c
+++ b/tools/gpio/gpio-hammer.c
@@ -77,7 +77,7 @@ int hammer_device(const char *device_name, unsigned int *lines, int nlines,
 
 		fprintf(stdout, "[%c] ", swirr[j]);
 		j++;
-		if (j == sizeof(swirr)-1)
+		if (j == sizeof(swirr) - 1)
 			j = 0;
 
 		fprintf(stdout, "[");
@@ -135,7 +135,14 @@ int main(int argc, char **argv)
 			device_name = optarg;
 			break;
 		case 'o':
-			lines[i] = strtoul(optarg, NULL, 10);
+			/*
+			 * Avoid overflow. Do not immediately error, we want to
+			 * be able to accurately report on the amount of times
+			 * '-o' was given to give an accurate error message
+			 */
+			if (i < GPIOHANDLES_MAX)
+				lines[i] = strtoul(optarg, NULL, 10);
+
 			i++;
 			break;
 		case '?':
@@ -143,6 +150,14 @@ int main(int argc, char **argv)
 			return -1;
 		}
 	}
+
+	if (i >= GPIOHANDLES_MAX) {
+		fprintf(stderr,
+			"Only %d occurrences of '-o' are allowed, %d were found\n",
+			GPIOHANDLES_MAX, i + 1);
+		return -1;
+	}
+
 	nlines = i;
 
 	if (!device_name || !nlines) {
diff --git a/tools/gpio/gpio-utils.c b/tools/gpio/gpio-utils.c
index 53470de6a502..06003789e7c7 100644
--- a/tools/gpio/gpio-utils.c
+++ b/tools/gpio/gpio-utils.c
@@ -17,7 +17,7 @@
 #include <linux/gpio.h>
 #include "gpio-utils.h"
 
-#define COMSUMER "gpio-utils"
+#define CONSUMER "gpio-utils"
 
 /**
  * doc: Operation of gpio
@@ -209,7 +209,7 @@ int gpiotools_gets(const char *device_name, unsigned int *lines,
 
 	ret = gpiotools_request_linehandle(device_name, lines, nlines,
 					   GPIOHANDLE_REQUEST_INPUT, data,
-					   COMSUMER);
+					   CONSUMER);
 	if (ret < 0)
 		return ret;
 
@@ -259,7 +259,7 @@ int gpiotools_sets(const char *device_name, unsigned int *lines,
 
 	ret = gpiotools_request_linehandle(device_name, lines, nlines,
 					   GPIOHANDLE_REQUEST_OUTPUT, data,
-					   COMSUMER);
+					   CONSUMER);
 	if (ret < 0)
 		return ret;
 
diff --git a/tools/gpio/gpio-watch.c b/tools/gpio/gpio-watch.c
new file mode 100644
index 000000000000..5cea24fddfa7
--- /dev/null
+++ b/tools/gpio/gpio-watch.c
@@ -0,0 +1,99 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * gpio-watch - monitor unrequested lines for property changes using the
+ *              character device
+ *
+ * Copyright (C) 2019 BayLibre SAS
+ * Author: Bartosz Golaszewski <bgolaszewski@baylibre.com>
+ */
+
+#include <ctype.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <linux/gpio.h>
+#include <poll.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/ioctl.h>
+#include <unistd.h>
+
+int main(int argc, char **argv)
+{
+	struct gpioline_info_changed chg;
+	struct gpioline_info req;
+	struct pollfd pfd;
+	int fd, i, j, ret;
+	char *event, *end;
+	ssize_t rd;
+
+	if (argc < 3)
+		goto err_usage;
+
+	fd = open(argv[1], O_RDWR | O_CLOEXEC);
+	if (fd < 0) {
+		perror("unable to open gpiochip");
+		return EXIT_FAILURE;
+	}
+
+	for (i = 0, j = 2; i < argc - 2; i++, j++) {
+		memset(&req, 0, sizeof(req));
+
+		req.line_offset = strtoul(argv[j], &end, 0);
+		if (*end != '\0')
+			goto err_usage;
+
+		ret = ioctl(fd, GPIO_GET_LINEINFO_WATCH_IOCTL, &req);
+		if (ret) {
+			perror("unable to set up line watch");
+			return EXIT_FAILURE;
+		}
+	}
+
+	pfd.fd = fd;
+	pfd.events = POLLIN | POLLPRI;
+
+	for (;;) {
+		ret = poll(&pfd, 1, 5000);
+		if (ret < 0) {
+			perror("error polling the linechanged fd");
+			return EXIT_FAILURE;
+		} else if (ret > 0) {
+			memset(&chg, 0, sizeof(chg));
+			rd = read(pfd.fd, &chg, sizeof(chg));
+			if (rd < 0 || rd != sizeof(chg)) {
+				if (rd != sizeof(chg))
+					errno = EIO;
+
+				perror("error reading line change event");
+				return EXIT_FAILURE;
+			}
+
+			switch (chg.event_type) {
+			case GPIOLINE_CHANGED_REQUESTED:
+				event = "requested";
+				break;
+			case GPIOLINE_CHANGED_RELEASED:
+				event = "released";
+				break;
+			case GPIOLINE_CHANGED_CONFIG:
+				event = "config changed";
+				break;
+			default:
+				fprintf(stderr,
+					"invalid event type received from the kernel\n");
+				return EXIT_FAILURE;
+			}
+
+			printf("line %u: %s at %llu\n",
+			       chg.info.line_offset, event, chg.timestamp);
+		}
+	}
+
+	return 0;
+
+err_usage:
+	printf("%s: <gpiochip> <line0> <line1> ...\n", argv[0]);
+	return EXIT_FAILURE;
+}