From: Michael Welling <mwelling@ieee.org>
To: Linus Walleij <linus.walleij@linaro.org>
Cc: linux-gpio@vger.kernel.org,
Alexandre Courbot <acourbot@nvidia.com>,
Markus Pargmann <mpa@pengutronix.de>,
Lee Campbell <leecam@google.com>,
Bamvor Jian Zhang <bamvor.zhangjian@linaro.org>,
Grant Likely <grant.likely@linaro.org>,
Arnd Bergmann <arnd@arndb.de>, Mark Brown <broonie@kernel.org>,
Dmitry Torokhov <dmitry.torokhov@gmail.com>,
Johan Hovold <johan@kernel.org>
Subject: Re: [PATCH 2/2] tools/gpio: add the gpio-hammer tool
Date: Wed, 27 Apr 2016 11:00:35 -0500 [thread overview]
Message-ID: <20160427160034.GA20392@deathstar> (raw)
In-Reply-To: <1461660866-18683-2-git-send-email-linus.walleij@linaro.org>
On Tue, Apr 26, 2016 at 10:54:26AM +0200, Linus Walleij wrote:
> The gpio-hammer is used from userspace as an example of how
> to retrieve a GPIO handle for one or several GPIO lines and
> hammer the outputs from low to high and back again. It will
> pulse the selected lines once per second for a specified
> number of times or indefinitely if no loop count is
> supplied.
>
> Example output:
> $ gpio-hammer -n gpiochip0 -o5 -o6 -o7
> Hammer lines [5, 6, 7] on gpiochip0, initial states: [1, 1, 1]
> [-] [5: 0, 6: 0, 7: 0]
>
> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Michael Welling <mwelling@ieee.org>
Below is the output from my target. You will notice that a kernel warning is spewed out if I use the mcp23s08.
The processor GPIOs work fine as verified by blinking LEDs.
root@som3517-som200:~# ./lsgpio
GPIO chip: gpiochip4, "mcp23s08", 8 GPIO lines
line 0: unnamed unused
line 1: unnamed unused
line 2: unnamed unused
line 3: unnamed unused
line 4: unnamed unused
line 5: unnamed unused
line 6: unnamed unused
line 7: unnamed unused
GPIO chip: gpiochip3, "gpio", 32 GPIO lines
line 0: unnamed unused
line 1: unnamed unused
line 2: unnamed unused
line 3: unnamed unused
line 4: unnamed unused
line 5: unnamed unused
line 6: unnamed unused
line 7: unnamed unused
line 8: unnamed "spi1.3" [kernel output]
line 9: unnamed unused
line 10: unnamed unused
line 11: unnamed unused
line 12: unnamed unused
line 13: unnamed unused
line 14: unnamed unused
line 15: unnamed unused
line 16: unnamed unused
line 17: unnamed unused
line 18: unnamed unused
line 19: unnamed unused
line 20: unnamed unused
line 21: unnamed unused
line 22: unnamed unused
line 23: unnamed unused
line 24: unnamed unused
line 25: unnamed unused
line 26: unnamed unused
line 27: unnamed unused
line 28: unnamed unused
line 29: unnamed unused
line 30: unnamed unused
line 31: unnamed unused
GPIO chip: gpiochip2, "gpio", 32 GPIO lines
line 0: unnamed unused
line 1: unnamed unused
line 2: unnamed unused
line 3: unnamed unused
line 4: unnamed unused
line 5: unname[ 40.820783] random: nonblocking pool is initialized
d unused
line 6: unnamed unused
line 7: unnamed unused
line 8: unnamed unused
line 9: unnamed unused
line 10: unnamed unused
line 11: unnamed unused
line 12: unnamed unused
line 13: unnamed unused
line 14: unnamed unused
line 15: unnamed unused
line 16: unnamed unused
line 17: unnamed unused
line 18: unnamed unused
line 19: unnamed unused
line 20: unnamed unused
line 21: unnamed unused
line 22: unnamed unused
line 23: unnamed unused
line 24: unnamed unused
line 25: unnamed unused
line 26: unnamed unused
line 27: unnamed unused
line 28: unnamed unused
line 29: unnamed unused
line 30: unnamed unused
line 31: unnamed unused
GPIO chip: gpiochip1, "gpio", 32 GPIO lines
line 0: unnamed unused
line 1: unnamed unused
line 2: unnamed unused
line 3: unnamed unused
line 4: unnamed unused
line 5: unnamed unused
line 6: unnamed unused
line 7: unnamed unused
line 8: unnamed unused
line 9: unnamed unused
line 10: unnamed unused
line 11: unnamed unused
line 12: unnamed "cd" [kernel active-low]
line 13: unnamed "enable" [kernel output]
line 14: unnamed "spi1.2" [kernel output]
line 15: unnamed unused
line 16: unnamed unused
line 17: unnamed unused
line 18: unnamed unused
line 19: unnamed unused
line 20: unnamed unused
line 21: unnamed unused
line 22: unnamed unused
line 23: unnamed unused
line 24: unnamed unused
line 25: unnamed unused
line 26: unnamed unused
line 27: unnamed unused
line 28: unnamed unused
line 29: unnamed unused
line 30: unnamed unused
line 31: unnamed unused
GPIO chip: gpiochip0, "gpio", 32 GPIO lines
line 0: unnamed unused
line 1: unnamed unused
line 2: unnamed unused
line 3: unnamed unused
line 4: unnamed unused
line 5: unnamed "spi1.0" [kernel output]
line 6: unnamed "spi1.1" [kernel output]
line 7: unnamed unused
line 8: unnamed unused
line 9: unnamed unused
line 10: unnamed unused
line 11: unnamed unused
line 12: unnamed unused
line 13: unnamed unused
line 14: unnamed unused
line 15: unnamed unused
line 16: unnamed unused
line 17: unnamed unused
line 18: unnamed unused
line 19: unnamed unused
line 20: unnamed unused
line 21: unnamed unused
line 22: unnamed unused
line 23: unnamed unused
line 24: unnamed unused
line 25: unnamed unused
line 26: unnamed unused
line 27: unnamed unused
line 28: unnamed unused
line 29: unnamed unused
line 30: unnamed unused
line 31: unnamed unused
root@som3517-som200:~# ./gpio-hammer -n gpiochip0 -o7
Hammer lines [7] on gpiochip0, initial states: [1]
^C] [7: 1]
root@som3517-som200:~# ./gpio-hammer -n gpiochip3 -o4
Hammer lines [4] on gpiochip3, initial states: [1]
^C] [4: 1]
root@som3517-som200:~# ./gpio-hammer -n gpiochip1 -o9
Hammer lines [9] on gpiochip1, initial states: [1]
^C] [9: 0]
root@som3517-som200:~# ./gpio-hammer -n gpiochip4 -o0
[ 187.511606] ------------[ cut here ]------------
[ 187.516949] WARNING: CPU: 0 PID: 830 at /home/michael/projects/linux/linux-git/drivers/gpio/gpiolib.c:1907 gpiod_get_value+0x60/0xa4
[ 187.529770] Modules linked in:
[ 187.533082] CPU: 0 PID: 830 Comm: gpio-hammer Tainted: G W 4.6.0-rc1-00084-g6f4ee91-dirty #2
[ 187.543231] Hardware name: Generic AM33XX (Flattened Device Tree)
[ 187.549753] [<c010fee4>] (unwind_backtrace) from [<c010c10c>] (show_stack+0x10/0x14)
[ 187.557993] [<c010c10c>] (show_stack) from [<c0464074>] (dump_stack+0xb0/0xe4)
[ 187.565695] [<c0464074>] (dump_stack) from [<c01345d4>] (__warn+0xd4/0x100)
[ 187.573109] [<c01345d4>] (__warn) from [<c01346ac>] (warn_slowpath_null+0x20/0x28)
[ 187.581163] [<c01346ac>] (warn_slowpath_null) from [<c049e3d8>] (gpiod_get_value+0x60/0xa4)
[ 187.590046] [<c049e3d8>] (gpiod_get_value) from [<c049f7a8>] (linehandle_ioctl+0x114/0x19c)
[ 187.598932] [<c049f7a8>] (linehandle_ioctl) from [<c0296710>] (do_vfs_ioctl+0x8c/0xa18)
[ 187.607445] [<c0296710>] (do_vfs_ioctl) from [<c0297108>] (SyS_ioctl+0x6c/0x7c)
[ 187.615233] [<c0297108>] (SyS_ioctl) from [<c0107820>] (ret_fast_syscall+0x0/0x1c)
[ 187.623616] ---[ end trace 9b8ac986d34a8efa ]---
.
.
root@som3517-som200:~# uname -a
Linux som3517-som200 4.6.0-rc1-00084-g6f4ee91-dirty #2 SMP Wed Apr 27 10:46:00 CDT 2016 armv7l GNU/Linux
root@som3517-som200:~# cat /proc/cpuinfo
processor : 0
model name : ARMv7 Processor rev 2 (v7l)
BogoMIPS : 273.94
Features : half thumb fastmult vfp edsp thumbee neon vfpv3 tls vfpd32
CPU implementer : 0x41
CPU architecture: 7
CPU variant : 0x3
CPU part : 0xc08
CPU revision : 2
Hardware : Generic AM33XX (Flattened Device Tree)
Revision : 0000
Serial : 0000000000000000
> ---
> tools/gpio/Makefile | 5 +-
> tools/gpio/gpio-hammer.c | 189 +++++++++++++++++++++++++++++++++++++++++++++++
> 2 files changed, 192 insertions(+), 2 deletions(-)
> create mode 100644 tools/gpio/gpio-hammer.c
>
> diff --git a/tools/gpio/Makefile b/tools/gpio/Makefile
> index c155d6bc47a7..aea23949054e 100644
> --- a/tools/gpio/Makefile
> +++ b/tools/gpio/Makefile
> @@ -1,12 +1,13 @@
> CC = $(CROSS_COMPILE)gcc
> CFLAGS += -O2 -Wall -g -D_GNU_SOURCE
>
> -all: lsgpio
> +all: lsgpio gpio-hammer
>
> lsgpio: lsgpio.o gpio-utils.o
> +gpio-hammer: gpio-hammer.o gpio-utils.o
>
> %.o: %.c gpio-utils.h
>
> .PHONY: clean
> clean:
> - rm -f *.o lsgpio
> + rm -f *.o lsgpio gpio-hammer
> diff --git a/tools/gpio/gpio-hammer.c b/tools/gpio/gpio-hammer.c
> new file mode 100644
> index 000000000000..37b3f141053d
> --- /dev/null
> +++ b/tools/gpio/gpio-hammer.c
> @@ -0,0 +1,189 @@
> +/*
> + * gpio-hammer - example swiss army knife to shake GPIO lines on a system
> + *
> + * Copyright (C) 2016 Linus Walleij
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms of the GNU General Public License version 2 as published by
> + * the Free Software Foundation.
> + *
> + * Usage:
> + * gpio-hammer -n <device-name> -o <offset1> -o <offset2>
> + */
> +
> +#include <unistd.h>
> +#include <stdlib.h>
> +#include <stdbool.h>
> +#include <stdio.h>
> +#include <dirent.h>
> +#include <errno.h>
> +#include <string.h>
> +#include <poll.h>
> +#include <fcntl.h>
> +#include <getopt.h>
> +#include <sys/ioctl.h>
> +#include <linux/gpio.h>
> +
> +int hammer_device(const char *device_name, unsigned int *lines, int nlines,
> + unsigned int loops)
> +{
> + struct gpiohandle_request req;
> + struct gpiohandle_data data;
> + char *chrdev_name;
> + char swirr[] = "-\\|/";
> + int fd;
> + int ret;
> + int i, j;
> + unsigned int iteration = 0;
> +
> + ret = asprintf(&chrdev_name, "/dev/%s", device_name);
> + if (ret < 0)
> + return -ENOMEM;
> +
> + fd = open(chrdev_name, 0);
> + if (fd == -1) {
> + ret = -errno;
> + fprintf(stderr, "Failed to open %s\n", chrdev_name);
> + goto exit_close_error;
> + }
> +
> + /* Request lines as output */
> + for (i = 0; i < nlines; i++)
> + req.lineoffsets[i] = lines[i];
> + req.flags = GPIOHANDLE_REQUEST_OUTPUT; /* Request as output */
> + strcpy(req.consumer_label, "gpio-hammer");
> + req.lines = nlines;
> + ret = ioctl(fd, GPIO_GET_LINEHANDLE_IOCTL, &req);
> + if (ret == -1) {
> + ret = -errno;
> + fprintf(stderr, "Failed to issue GET LINEHANDLE "
> + "IOCTL (%d)\n",
> + ret);
> + goto exit_close_error;
> + }
> +
> + /* Read initial states */
> + ret = ioctl(req.fd, GPIOHANDLE_GET_LINE_VALUES_IOCTL, &data);
> + if (ret == -1) {
> + ret = -errno;
> + fprintf(stderr, "Failed to issue GPIOHANDLE GET LINE "
> + "VALUES IOCTL (%d)\n",
> + ret);
> + goto exit_close_error;
> + }
> + fprintf(stdout, "Hammer lines [");
> + for (i = 0; i < nlines; i++) {
> + fprintf(stdout, "%d", lines[i]);
> + if (i != (nlines - 1))
> + fprintf(stdout, ", ");
> + }
> + fprintf(stdout, "] on %s, initial states: [", device_name);
> + for (i = 0; i < nlines; i++) {
> + fprintf(stdout, "%d", data.values[i]);
> + if (i != (nlines - 1))
> + fprintf(stdout, ", ");
> + }
> + fprintf(stdout, "]\n");
> +
> + /* Hammertime! */
> + j = 0;
> + while (1) {
> + /* Invert all lines so we blink */
> + for (i = 0; i < nlines; i++)
> + data.values[i] = !data.values[i];
> +
> + ret = ioctl(req.fd, GPIOHANDLE_SET_LINE_VALUES_IOCTL, &data);
> + if (ret == -1) {
> + ret = -errno;
> + fprintf(stderr, "Failed to issue GPIOHANDLE SET LINE "
> + "VALUES IOCTL (%d)\n",
> + ret);
> + goto exit_close_error;
> + }
> + /* Re-read values to get status */
> + ret = ioctl(req.fd, GPIOHANDLE_GET_LINE_VALUES_IOCTL, &data);
> + if (ret == -1) {
> + ret = -errno;
> + fprintf(stderr, "Failed to issue GPIOHANDLE GET LINE "
> + "VALUES IOCTL (%d)\n",
> + ret);
> + goto exit_close_error;
> + }
> +
> + fprintf(stdout, "[%c] ", swirr[j]);
> + j++;
> + if (j == sizeof(swirr)-1)
> + j = 0;
> +
> + fprintf(stdout, "[");
> + for (i = 0; i < nlines; i++) {
> + fprintf(stdout, "%d: %d", lines[i], data.values[i]);
> + if (i != (nlines - 1))
> + fprintf(stdout, ", ");
> + }
> + fprintf(stdout, "]\r");
> + fflush(stdout);
> + sleep(1);
> + iteration++;
> + if (loops && iteration == loops)
> + break;
> + }
> + fprintf(stdout, "\n");
> + ret = 0;
> +
> +exit_close_error:
> + if (close(fd) == -1)
> + perror("Failed to close GPIO character device file");
> + free(chrdev_name);
> + return ret;
> +}
> +
> +void print_usage(void)
> +{
> + fprintf(stderr, "Usage: gpio-hammer [options]...\n"
> + "Hammer GPIO lines, 0->1->0->1...\n"
> + " -n <name> Hammer GPIOs on a named device (must be stated)\n"
> + " -o <n> Offset[s] to hammer, at least one, several can be stated\n"
> + " [-c <n>] Do <n> loops (optional, infinite loop if not stated)\n"
> + " -? This helptext\n"
> + "\n"
> + "Example:\n"
> + "gpio-hammer -n gpiochip0 -o 4\n"
> + );
> +}
> +
> +int main(int argc, char **argv)
> +{
> + const char *device_name = NULL;
> + unsigned int lines[GPIOHANDLES_MAX];
> + unsigned int loops = 0;
> + int nlines;
> + int c;
> + int i;
> +
> + i = 0;
> + while ((c = getopt(argc, argv, "c:n:o:?")) != -1) {
> + switch (c) {
> + case 'c':
> + loops = strtoul(optarg, NULL, 10);
> + break;
> + case 'n':
> + device_name = optarg;
> + break;
> + case 'o':
> + lines[i] = strtoul(optarg, NULL, 10);
> + i++;
> + break;
> + case '?':
> + print_usage();
> + return -1;
> + }
> + }
> + nlines = i;
> +
> + if (!device_name || !nlines) {
> + print_usage();
> + return -1;
> + }
> + return hammer_device(device_name, lines, nlines, loops);
> +}
> --
> 2.4.11
>
next prev parent reply other threads:[~2016-04-27 16:00 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-26 8:54 [PATCH 1/2] gpio: userspace ABI for reading/writing GPIO lines Linus Walleij
2016-04-26 8:54 ` [PATCH 2/2] tools/gpio: add the gpio-hammer tool Linus Walleij
2016-04-27 16:00 ` Michael Welling [this message]
2016-05-31 11:59 ` Linus Walleij
2016-06-01 3:43 ` Michael Welling
2016-06-01 17:35 ` Linus Walleij
2016-06-01 18:09 ` Michael Welling
2016-06-01 21:40 ` Linus Walleij
2016-06-02 14:59 ` Michael Welling
2016-06-15 9:48 ` Linus Walleij
2016-04-28 7:47 ` Alexander Stein
2016-04-26 16:44 ` [PATCH 1/2] gpio: userspace ABI for reading/writing GPIO lines Dmitry Torokhov
2016-05-27 13:22 ` Linus Walleij
2016-05-27 17:36 ` Dmitry Torokhov
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