From patchwork Tue Jan 11 13:37:19 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bartosz Golaszewski X-Patchwork-Id: 531286 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7178BC433F5 for ; Tue, 11 Jan 2022 13:37:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240618AbiAKNha (ORCPT ); Tue, 11 Jan 2022 08:37:30 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44334 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240572AbiAKNha (ORCPT ); Tue, 11 Jan 2022 08:37:30 -0500 Received: from mail-wr1-x436.google.com (mail-wr1-x436.google.com [IPv6:2a00:1450:4864:20::436]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CF5B4C06173F for ; Tue, 11 Jan 2022 05:37:29 -0800 (PST) Received: by mail-wr1-x436.google.com with SMTP id l25so22153467wrb.13 for ; Tue, 11 Jan 2022 05:37:29 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bgdev-pl.20210112.gappssmtp.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=h8p80Tn6IMEQvSpV9M3jq2rt7b4lafUnGCFI66AEg9s=; b=xgRGjqhVI/1VZqgNPFjDggRAZmJLDTFkuIBPeaD0JiY6r9CuBbhe2x6oLZH3HUbRxM 9zD/P+H3nUDqKcxi6eQ9XIvWVjrrraMfXnb2T8piQCQhNiaEvC8okYOnMBOPeOm2wrRv VHoGviPIVfvn4jtsu3ycz93rbcdr/fMRNno1tSsaTBrmdG/6A1Q9y4iBpR0E8y3wy8XA Xdb30yfCWyQ0Na/godR4exn5HgHsIge2Id2DxyAJe9Fn7beoJyUIxM08K7ekNCLP4Q4E cYi8ZQct4ZNXbzz+j2QOFJw7Gmhy18K+g+jpWesOAS+QbApsSXJOORPw9IXKHv8tBi3D E4yg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=h8p80Tn6IMEQvSpV9M3jq2rt7b4lafUnGCFI66AEg9s=; b=Lcf4JDqu9yNSU6j2EKpDb34LgjkHisDlo9sOu1BzCZBK14U6Tj5T3HIMx6MoLvS8M7 +wR0VbV5Pw8FY7Z9nBMfi5tRl9B+lblgjFrmQyCa3RBNTFCWDPDTu2doa8hv5MU7VIxE W3lT9kukZsqxzTKpPqA6cpFFUY/t6skaN57LYa4gY09n90LbST2JY9MBVuTtso9h0sgw ruaqIfC7+Yz7LW1wJlVm5b3eXXdNUGppRmc/tacPNt7ietdMvsOH/VSK0RMryShJ5f8W Qe3qvIn6tDafbMHs3sEDN0fXwAqSKzc08FhHM+2+4uRGcPr91XK/kmS8OEKeqZVXzY78 mxtg== X-Gm-Message-State: AOAM533/SjJbMCqdO5NQZUqpprgmeE3WrnhqYZi9ElMz6cLky2aG3dXR 38B87z5bXzqVJ2SBtW6HaF17Xg== X-Google-Smtp-Source: ABdhPJyw/06MoaCRxCCw8L1D5bLPRxDFeOJiaLHVCbhSiIohFPM3SE/mTFOi3AhSd22rRjDYWzpzRA== X-Received: by 2002:adf:edcf:: with SMTP id v15mr3784099wro.501.1641908248143; Tue, 11 Jan 2022 05:37:28 -0800 (PST) Received: from debian-brgl.home ([2a01:cb1d:334:ac00:7d50:ff5:f5c1:e225]) by smtp.gmail.com with ESMTPSA id f9sm1976186wry.115.2022.01.11.05.37.27 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 11 Jan 2022 05:37:27 -0800 (PST) From: Bartosz Golaszewski To: Kent Gibson , Linus Walleij , Andy Shevchenko , Viresh Kumar Cc: linux-gpio@vger.kernel.org, Bartosz Golaszewski Subject: [PATCH 1/2] libgpiosim: new library for controlling the gpio-sim module Date: Tue, 11 Jan 2022 14:37:19 +0100 Message-Id: <20220111133720.713541-2-brgl@bgdev.pl> X-Mailer: git-send-email 2.30.1 In-Reply-To: <20220111133720.713541-1-brgl@bgdev.pl> References: <20220111133720.713541-1-brgl@bgdev.pl> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org Add a C library for controlling the gpio-sim kernel module from various libgpiod test suites. This aims at replacing the old gpio-mockup module and its user-space library - libgpio-mockup - in the project's tree. Signed-off-by: Bartosz Golaszewski --- configure.ac | 7 +- tests/Makefile.am | 4 +- tests/gpiosim/.gitignore | 4 + tests/gpiosim/Makefile.am | 16 + tests/gpiosim/gpiosim-selftest.c | 157 +++++ tests/gpiosim/gpiosim.c | 1009 ++++++++++++++++++++++++++++++ tests/gpiosim/gpiosim.h | 64 ++ 7 files changed, 1257 insertions(+), 4 deletions(-) create mode 100644 tests/gpiosim/.gitignore create mode 100644 tests/gpiosim/Makefile.am create mode 100644 tests/gpiosim/gpiosim-selftest.c create mode 100644 tests/gpiosim/gpiosim.c create mode 100644 tests/gpiosim/gpiosim.h diff --git a/configure.ac b/configure.ac index ce6de99..8e74104 100644 --- a/configure.ac +++ b/configure.ac @@ -1,5 +1,5 @@ # SPDX-License-Identifier: GPL-2.0-or-later -# SPDX-FileCopyrightText: 2017-2021 Bartosz Golaszewski +# SPDX-FileCopyrightText: 2017-2022 Bartosz Golaszewski AC_PREREQ([2.69]) @@ -31,6 +31,7 @@ AC_SUBST(ABI_CXX_VERSION, [2.1.1]) # ABI version for libgpiomockup (we need this since it can be installed if we # enable install-tests). AC_SUBST(ABI_MOCKUP_VERSION, [0.1.0]) +AC_SUBST(ABI_GPIOSIM_VERSION, [0.1.0]) AC_CONFIG_AUX_DIR([autostuff]) AC_CONFIG_MACRO_DIRS([m4]) @@ -126,10 +127,11 @@ AC_DEFUN([FUNC_NOT_FOUND_TESTS], if test "x$with_tests" = xtrue then - # For libgpiomockup + # For libgpiomockup & libgpiosim AC_CHECK_FUNC([qsort], [], [FUNC_NOT_FOUND_TESTS([qsort])]) PKG_CHECK_MODULES([KMOD], [libkmod >= 18]) PKG_CHECK_MODULES([UDEV], [libudev >= 215]) + PKG_CHECK_MODULES([MOUNT], [mount >= 2.33.1]) # For core library tests PKG_CHECK_MODULES([GLIB], [glib-2.0 >= 2.50]) @@ -224,6 +226,7 @@ AC_CONFIG_FILES([Makefile tools/Makefile tests/Makefile tests/mockup/Makefile + tests/gpiosim/Makefile bindings/cxx/libgpiodcxx.pc bindings/Makefile bindings/cxx/Makefile diff --git a/tests/Makefile.am b/tests/Makefile.am index 43b215e..8a3d7c9 100644 --- a/tests/Makefile.am +++ b/tests/Makefile.am @@ -1,7 +1,7 @@ # SPDX-License-Identifier: GPL-2.0-or-later -# SPDX-FileCopyrightText: 2017-2021 Bartosz Golaszewski +# SPDX-FileCopyrightText: 2017-2022 Bartosz Golaszewski -SUBDIRS = mockup +SUBDIRS = mockup gpiosim AM_CFLAGS = -I$(top_srcdir)/include/ -I$(top_srcdir)/tests/mockup/ AM_CFLAGS += -include $(top_builddir)/config.h diff --git a/tests/gpiosim/.gitignore b/tests/gpiosim/.gitignore new file mode 100644 index 0000000..5731644 --- /dev/null +++ b/tests/gpiosim/.gitignore @@ -0,0 +1,4 @@ +# SPDX-License-Identifier: GPL-2.0-or-later +# SPDX-FileCopyrightText: 2017-2022 Bartosz Golaszewski + +gpiosim-selftest diff --git a/tests/gpiosim/Makefile.am b/tests/gpiosim/Makefile.am new file mode 100644 index 0000000..ab5838a --- /dev/null +++ b/tests/gpiosim/Makefile.am @@ -0,0 +1,16 @@ +# SPDX-License-Identifier: GPL-2.0-or-later +# SPDX-FileCopyrightText: 2021-2022 Bartosz Golaszewski + +lib_LTLIBRARIES = libgpiosim.la +noinst_PROGRAMS = gpiosim-selftest + +AM_CFLAGS = -Wall -Wextra -g -fvisibility=hidden -std=gnu89 +AM_CFLAGS += -include $(top_builddir)/config.h + +libgpiosim_la_SOURCES = gpiosim.c gpiosim.h +libgpiosim_la_CFLAGS = $(AM_CFLAGS) $(KMOD_CFLAGS) $(MOUNT_CFLAGS) +libgpiosim_la_LDFLAGS = -version-info $(subst .,:,$(ABI_GPIOSIM_VERSION)) +libgpiosim_la_LDFLAGS += $(KMOD_LIBS) $(MOUNT_LIBS) + +gpiosim_selftest_SOURCES = gpiosim-selftest.c +gpiosim_selftest_LDADD = libgpiosim.la diff --git a/tests/gpiosim/gpiosim-selftest.c b/tests/gpiosim/gpiosim-selftest.c new file mode 100644 index 0000000..205580d --- /dev/null +++ b/tests/gpiosim/gpiosim-selftest.c @@ -0,0 +1,157 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +// SPDX-FileCopyrightText: 2021-2022 Bartosz Golaszewski + +#include +#include + +#include "gpiosim.h" + +#define UNUSED __attribute__((unused)) + +static const char *const line_names[] = { + "foo", + "bar", + "foobar", + NULL, + "barfoo", +}; + +int main(int argc UNUSED, char **argv UNUSED) +{ + struct gpiosim_bank *bank0, *bank1; + struct gpiosim_dev *dev; + struct gpiosim_ctx *ctx; + int ret, i; + + printf("Creating gpiosim context\n"); + + ctx = gpiosim_ctx_new(); + if (!ctx) { + perror("unable to create the gpios-sim context"); + return EXIT_FAILURE; + } + + printf("Creating a chip with random name\n"); + + dev = gpiosim_dev_new(ctx, NULL); + if (!dev) { + perror("Unable to create a chip with random name"); + return EXIT_FAILURE; + } + + printf("Creating a bank with a random name\n"); + + bank0 = gpiosim_bank_new(dev, NULL); + if (!bank0) { + perror("Unable to create a bank with random name"); + return EXIT_FAILURE; + } + + printf("Creating a bank with a specific name\n"); + + bank1 = gpiosim_bank_new(dev, "foobar"); + if (!bank1) { + perror("Unable to create a bank with a specific name"); + return EXIT_FAILURE; + } + + printf("Setting the label of bank #2 to foobar\n"); + + ret = gpiosim_bank_set_label(bank1, "foobar"); + if (ret) { + perror("Unable to set the label of bank #2"); + return EXIT_FAILURE; + } + + printf("Setting the number of lines in bank #1 to 16\n"); + + ret = gpiosim_bank_set_num_lines(bank0, 16); + if (ret) { + perror("Unable to set the number of lines"); + return EXIT_FAILURE; + } + + printf("Setting the number of lines in bank #2 to 8\n"); + + ret = gpiosim_bank_set_num_lines(bank1, 8); + if (ret) { + perror("Unable to set the number of lines"); + return EXIT_FAILURE; + } + + printf("Setting names for some lines in bank #1\n"); + + for (i = 0; i < 5; i++) { + ret = gpiosim_bank_set_line_name(bank0, i, line_names[i]); + if (ret) { + perror("Unable to set line names"); + return EXIT_FAILURE; + } + } + + printf("Hog a line on bank #2\n"); + + ret = gpiosim_bank_hog_line(bank1, 3, "xyz", + GPIOSIM_HOG_DIR_OUTPUT_HIGH); + if (ret) { + perror("Unable to hog a line"); + return EXIT_FAILURE; + } + + printf("Enabling the GPIO device\n"); + + ret = gpiosim_dev_enable(dev); + if (ret) { + perror("Unable to enable the device"); + return EXIT_FAILURE; + } + + printf("Setting the pull of a single line to pull-up\n"); + + ret = gpiosim_bank_set_pull(bank0, 6, GPIOSIM_PULL_UP); + if (ret) { + perror("Unable to set the pull"); + return EXIT_FAILURE; + } + + printf("Reading the pull back\n"); + + ret = gpiosim_bank_get_pull(bank0, 6); + if (ret < 0) { + perror("Unable to read the pull"); + return EXIT_FAILURE; + } + + if (ret != GPIOSIM_PULL_UP) { + fprintf(stderr, "Invalid pull value read\n"); + return EXIT_FAILURE; + } + + printf("Reading the value\n"); + + ret = gpiosim_bank_get_value(bank0, 6); + if (ret < 0) { + perror("Unable to read the value"); + return EXIT_FAILURE; + } + + if (ret != 1) { + fprintf(stderr, "Invalid value read\n"); + return EXIT_FAILURE; + } + + printf("Disabling the GPIO device\n"); + + ret = gpiosim_dev_disable(dev); + if (ret) { + perror("Error while disabling the device"); + return EXIT_FAILURE; + } + + gpiosim_bank_unref(bank1); + gpiosim_bank_unref(bank0); + gpiosim_dev_unref(dev); + gpiosim_ctx_unref(ctx); + + return EXIT_SUCCESS; +} diff --git a/tests/gpiosim/gpiosim.c b/tests/gpiosim/gpiosim.c new file mode 100644 index 0000000..60a3e50 --- /dev/null +++ b/tests/gpiosim/gpiosim.c @@ -0,0 +1,1009 @@ +// SPDX-License-Identifier: LGPL-2.1-or-later +// SPDX-FileCopyrightText: 2021-2022 Bartosz Golaszewski + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "gpiosim.h" + +#define GPIOSIM_API __attribute__((visibility("default"))) +#define ARRAY_SIZE(x) (sizeof(x) / sizeof(*(x))) +#define MIN_KERNEL_VERSION KERNEL_VERSION(5, 15, 0) + +struct refcount { + unsigned int cnt; + void (*release)(struct refcount *); +}; + +static void refcount_init(struct refcount *ref, + void (*release)(struct refcount *)) +{ + ref->cnt = 1; + ref->release = release; +} + +static void refcount_inc(struct refcount *ref) +{ + ref->cnt++; +} + +static void refcount_dec(struct refcount *ref) +{ + ref->cnt--; + + if (!ref->cnt) + ref->release(ref); +} + +struct list_head { + struct list_head *prev; + struct list_head *next; +}; + +static void list_init(struct list_head *list) +{ + list->next = list; + list->prev = list; +} + +static void list_add(struct list_head *new, struct list_head *head) +{ + struct list_head *prev = head->prev; + + head->prev = new; + new->next = head; + new->prev = prev; + prev->next = new; +} + +static void list_del(struct list_head *entry) +{ + struct list_head *prev = entry->prev, *next = entry->next; + + prev->next = next; + next->prev = prev; +} + +#define container_of(ptr, type, member) ({ \ + void *__mptr = (void *)(ptr); \ + ((type *)(__mptr - offsetof(type, member))); \ +}) + +#define list_entry(ptr, type, member) \ + container_of(ptr, type, member) + +#define list_first_entry(ptr, type, member) \ + list_entry((ptr)->next, type, member) + +#define list_next_entry(pos, member) \ + list_entry((pos)->member.next, typeof(*(pos)), member) + +#define list_entry_is_head(pos, head, member) \ + (&pos->member == (head)) + +#define list_for_each_entry(pos, head, member) \ + for (pos = list_first_entry(head, typeof(*pos), member); \ + !list_entry_is_head(pos, head, member); \ + pos = list_next_entry(pos, member)) + +static int open_write_close(int base_fd, const char *where, const char *what) +{ + ssize_t written, size = strlen(what) + 1; + int fd; + + fd = openat(base_fd, where, O_WRONLY); + if (fd < 0) + return -1; + + written = write(fd, what, size); + close(fd); + if (written < 0) { + return -1; + } else if (written != size) { + errno = EIO; + return -1; + } + + return 0; +} + +static int open_read_close(int base_fd, const char *where, + char *buf, size_t bufsize) +{ + ssize_t rd; + int fd; + + fd = openat(base_fd, where, O_RDONLY); + if (fd < 0) + return -1; + + memset(buf, 0, bufsize); + rd = read(fd, buf, bufsize); + close(fd); + if (rd < 0) + return -1; + + if (buf[rd - 1] == '\n') + buf[rd - 1] = '\0'; + + return 0; +} + +static int check_kernel_version(void) +{ + unsigned int major, minor, release; + struct utsname un; + int ret; + + ret = uname(&un); + if (ret) + return -1; + + ret = sscanf(un.release, "%u.%u.%u", &major, &minor, &release); + if (ret != 3) { + errno = EFAULT; + return -1; + } + + if (KERNEL_VERSION(major, minor, release) < MIN_KERNEL_VERSION) { + errno = EOPNOTSUPP; + return -1; + } + + return 0; +} + +static int check_gpiosim_module(void) +{ + struct kmod_module *module; + struct kmod_ctx *kmod; + const char *modpath; + int ret, initstate; + + kmod = kmod_new(NULL, NULL); + if (!kmod) + return -1; + + ret = kmod_module_new_from_name(kmod, "gpio-sim", &module); + if (ret) + goto out_unref_kmod; + +again: + /* First check if the module is already loaded or built-in. */ + initstate = kmod_module_get_initstate(module); + if (initstate < 0) { + if (errno == ENOENT) { + /* + * It's not loaded, let's see if we can do it manually. + * See if we can find the module. + */ + modpath = kmod_module_get_path(module); + if (!modpath) { + /* libkmod doesn't set errno. */ + errno = ENOENT; + ret = -1; + goto out_unref_module; + } + + ret = kmod_module_probe_insert_module(module, + KMOD_PROBE_IGNORE_LOADED, + NULL, NULL, NULL, NULL); + if (ret) + goto out_unref_module; + + goto again; + } else { + if (errno == 0) + errno = EOPNOTSUPP; + + goto out_unref_module; + } + } + + if (initstate != KMOD_MODULE_BUILTIN && + initstate != KMOD_MODULE_LIVE && + initstate != KMOD_MODULE_COMING) { + errno = EPERM; + goto out_unref_module; + } + + ret = 0; + +out_unref_module: + kmod_module_unref(module); +out_unref_kmod: + kmod_unref(kmod); + return ret; +} + +/* We don't have mkdtempat()... :( */ +static char *make_random_dir_at(int at) +{ + static const char chars[] = "abcdefghijklmnoprstquvwxyz" + "ABCDEFGHIJKLMNOPRSTQUVWXYZ" + "0123456789"; + + char name[] = "XXXXXXXXXXXX\0"; + unsigned int idx, i; + int ret; + +again: + for (i = 0; i < sizeof(name) - 1; i++) { + ret = getrandom(&idx, sizeof(idx), GRND_NONBLOCK); + if (ret != sizeof(idx)) { + if (ret >= 0) + errno = EAGAIN; + + return NULL; + } + + name[i] = chars[idx % (ARRAY_SIZE(chars) - 1)]; + } + + ret = mkdirat(at, name, 0600); + if (ret) { + if (errno == EEXIST) + goto again; + + return NULL; + } + + return strdup(name); +} + +static char *configfs_make_item_name(int at, const char *name) +{ + char *item_name; + int ret; + + if (name) { + item_name = strdup(name); + if (!item_name) + return NULL; + + ret = mkdirat(at, item_name, 0600); + if (ret) { + free(item_name); + return NULL; + } + } else { + item_name = make_random_dir_at(at); + if (!item_name) + return NULL; + } + + return item_name; +} + +struct gpiosim_ctx { + struct refcount refcnt; + int cfs_dir_fd; + char *cfs_mnt_dir; +}; + +struct gpiosim_dev { + struct refcount refcnt; + struct gpiosim_ctx *ctx; + bool live; + char *item_name; + char *dev_name; + int cfs_dir_fd; + int sysfs_dir_fd; + struct list_head banks; +}; + +struct gpiosim_bank { + struct refcount refcnt; + struct gpiosim_dev *dev; + struct list_head siblings; + char *item_name; + char *chip_name; + char *dev_path; + int cfs_dir_fd; + int sysfs_dir_fd; + unsigned int num_lines; +}; + +static int ctx_open_configfs_dir(struct gpiosim_ctx *ctx, const char *cfs_path) +{ + char *path; + int ret; + + ret = asprintf(&path, "%s/gpio-sim", cfs_path); + if (ret < 0) + return -1; + + ctx->cfs_dir_fd = open(path, O_RDONLY); + free(path); + if (ctx->cfs_dir_fd < 0) + return -1; + + return 0; +} + +/* + * We don't need to check the configfs module as loading gpio-sim will pull it + * in but we need to find out if and where configfs was mounted. If it wasn't + * then as a last resort we'll try to mount it ourselves. + */ +static int ctx_get_configfs_fd(struct gpiosim_ctx *ctx) +{ + struct libmnt_context *mntctx; + struct libmnt_iter *iter; + struct libmnt_table *tb; + struct libmnt_fs *fs; + const char *type; + int ret; + + /* Try to find out if and where configfs is mounted. */ + mntctx = mnt_new_context(); + if (!mntctx) + return -1; + + ret = mnt_context_get_mtab(mntctx, &tb); + if (ret) + goto out_free_ctx; + + iter = mnt_new_iter(MNT_ITER_FORWARD); + if (!iter) + goto out_free_ctx; + + while (mnt_table_next_fs(tb, iter, &fs) == 0) { + type = mnt_fs_get_fstype(fs); + + if (strcmp(type, "configfs") == 0) { + ret = ctx_open_configfs_dir(ctx, mnt_fs_get_target(fs)); + if (ret) + goto out_free_iter; + + ret = 0; + goto out_free_iter; + } + } + + /* Didn't find any configfs mounts - let's try to do it ourselves. */ + ctx->cfs_mnt_dir = strdup("/tmp/gpiosim-configfs-XXXXXX"); + if (!ctx->cfs_mnt_dir) + goto out_free_iter; + + ctx->cfs_mnt_dir = mkdtemp(ctx->cfs_mnt_dir); + if (!ctx->cfs_mnt_dir) + goto out_free_tmpdir; + + ret = mount(NULL, ctx->cfs_mnt_dir, "configfs", MS_RELATIME, NULL); + if (ret) + goto out_rm_tmpdir; + + ret = ctx_open_configfs_dir(ctx, ctx->cfs_mnt_dir); + if (ret == 0) + /* Skip unmounting & deleting the tmp directory on success. */ + goto out_free_iter; + + umount(ctx->cfs_mnt_dir); +out_rm_tmpdir: + rmdir(ctx->cfs_mnt_dir); +out_free_tmpdir: + free(ctx->cfs_mnt_dir); + ctx->cfs_mnt_dir = NULL; +out_free_iter: + mnt_free_iter(iter); +out_free_ctx: + mnt_free_context(mntctx); + + return ret; +} + +static void ctx_release(struct refcount *ref) +{ + struct gpiosim_ctx *ctx = container_of(ref, struct gpiosim_ctx, refcnt); + + close(ctx->cfs_dir_fd); + + if (ctx->cfs_mnt_dir) { + umount(ctx->cfs_mnt_dir); + rmdir(ctx->cfs_mnt_dir); + free(ctx->cfs_mnt_dir); + } + + free(ctx); +} + +GPIOSIM_API struct gpiosim_ctx *gpiosim_ctx_new(void) +{ + struct gpiosim_ctx *ctx; + int ret; + + ret = check_kernel_version(); + if (ret) + return NULL; + + ret = check_gpiosim_module(); + if (ret) + return NULL; + + ctx = malloc(sizeof(*ctx)); + if (!ctx) + return NULL; + + memset(ctx, 0, sizeof(*ctx)); + refcount_init(&ctx->refcnt, ctx_release); + + ret = ctx_get_configfs_fd(ctx); + if (ret) { + free(ctx); + return NULL; + } + + return ctx; +} + +GPIOSIM_API struct gpiosim_ctx *gpiosim_ctx_ref(struct gpiosim_ctx *ctx) +{ + refcount_inc(&ctx->refcnt); + + return ctx; +} + +GPIOSIM_API void gpiosim_ctx_unref(struct gpiosim_ctx *ctx) +{ + refcount_dec(&ctx->refcnt); +} + +static void dev_release(struct refcount *ref) +{ + struct gpiosim_dev *dev = container_of(ref, struct gpiosim_dev, refcnt); + struct gpiosim_ctx *ctx = dev->ctx; + + if (dev->live) + gpiosim_dev_disable(dev); + + unlinkat(ctx->cfs_dir_fd, dev->item_name, AT_REMOVEDIR); + close(dev->cfs_dir_fd); + free(dev->dev_name); + free(dev->item_name); + gpiosim_ctx_unref(ctx); + free(dev); +} + +GPIOSIM_API struct gpiosim_dev * +gpiosim_dev_new(struct gpiosim_ctx *ctx, const char *name) +{ + struct gpiosim_dev *dev; + int configfs_fd, ret; + char devname[128]; + char *item_name; + + item_name = configfs_make_item_name(ctx->cfs_dir_fd, name); + if (!item_name) + return NULL; + + configfs_fd = openat(ctx->cfs_dir_fd, item_name, O_RDONLY); + if (configfs_fd < 0) + goto err_unlink; + + dev = malloc(sizeof(*dev)); + if (!dev) + goto err_close_fd; + + ret = open_read_close(configfs_fd, "dev_name", + devname, sizeof(devname)); + if (ret) + goto err_free_dev; + + memset(dev, 0, sizeof(*dev)); + refcount_init(&dev->refcnt, dev_release); + list_init(&dev->banks); + dev->cfs_dir_fd = configfs_fd; + dev->sysfs_dir_fd = -1; + dev->item_name = item_name; + + dev->dev_name = strdup(devname); + if (!dev->dev_name) + goto err_free_dev; + + dev->ctx = gpiosim_ctx_ref(ctx); + + return dev; + +err_free_dev: + free(dev); +err_close_fd: + close(configfs_fd); +err_unlink: + unlinkat(ctx->cfs_dir_fd, item_name, AT_REMOVEDIR); + free(item_name); + + return NULL; +} + +GPIOSIM_API struct gpiosim_dev *gpiosim_dev_ref(struct gpiosim_dev *dev) +{ + refcount_inc(&dev->refcnt); + + return dev; +} + +GPIOSIM_API void gpiosim_dev_unref(struct gpiosim_dev *dev) +{ + refcount_dec(&dev->refcnt); +} + +GPIOSIM_API const char *gpiosim_dev_get_name(struct gpiosim_dev *dev) +{ + return dev->dev_name; +} + +static bool dev_check_pending(struct gpiosim_dev *dev) +{ + if (dev->live) + errno = EBUSY; + + return !dev->live; +} + +static bool dev_check_live(struct gpiosim_dev *dev) +{ + if (!dev->live) + errno = ENODEV; + + return dev->live; +} + +static int bank_set_chip_name(struct gpiosim_bank *bank) +{ + char chip_name[32]; + int ret; + + ret = open_read_close(bank->cfs_dir_fd, "chip_name", + chip_name, sizeof(chip_name)); + if (ret) + return -1; + + bank->chip_name = strdup(chip_name); + if (!bank->chip_name) + return -1; + + return 0; +} + +static int bank_set_dev_path(struct gpiosim_bank *bank) +{ + char dev_path[64]; + + snprintf(dev_path, sizeof(dev_path), "/dev/%s", bank->chip_name); + + bank->dev_path = strdup(dev_path); + if (!bank->dev_path) + return -1; + + return 0; +} + +static int bank_open_sysfs_dir(struct gpiosim_bank *bank) +{ + struct gpiosim_dev *dev = bank->dev; + int fd; + + fd = openat(dev->sysfs_dir_fd, bank->chip_name, O_RDONLY); + if (fd < 0) + return -1; + + bank->sysfs_dir_fd = fd; + + return 0; +} + +static int bank_enable(struct gpiosim_bank *bank) +{ + int ret; + + ret = bank_set_chip_name(bank); + if (ret) + return -1; + + ret = bank_set_dev_path(bank); + if (ret) + return -1; + + return bank_open_sysfs_dir(bank); +} + +static int dev_open_sysfs_dir(struct gpiosim_dev *dev) +{ + int ret, fd; + char *sysp; + + ret = asprintf(&sysp, "/sys/devices/platform/%s", dev->dev_name); + if (ret < 0) + return -1; + + fd = open(sysp, O_RDONLY); + free(sysp); + if (fd < 0) + return -1; + + dev->sysfs_dir_fd = fd; + + return 0; +} + +/* Closes the sysfs dir for this device and all its child banks. */ +static void dev_close_sysfs_dirs(struct gpiosim_dev *dev) +{ + struct gpiosim_bank *bank; + + list_for_each_entry(bank, &dev->banks, siblings) { + free(bank->chip_name); + free(bank->dev_path); + bank->chip_name = bank->dev_path = NULL; + + if (bank->sysfs_dir_fd < 0) + break; + + close(bank->sysfs_dir_fd); + bank->sysfs_dir_fd = -1; + } + + close(dev->sysfs_dir_fd); + dev->sysfs_dir_fd = -1; +} + +GPIOSIM_API int gpiosim_dev_enable(struct gpiosim_dev *dev) +{ + struct gpiosim_bank *bank; + int ret; + + if (!dev_check_pending(dev)) + return -1; + + ret = open_write_close(dev->cfs_dir_fd, "live", "1"); + if (ret) + return -1; + + ret = dev_open_sysfs_dir(dev); + if (ret) { + open_write_close(dev->cfs_dir_fd, "live", "0"); + return -1; + } + + bank = container_of(&dev->banks, struct gpiosim_bank, siblings); + + list_for_each_entry(bank, &dev->banks, siblings) { + ret = bank_enable(bank); + if (ret) { + dev_close_sysfs_dirs(dev); + open_write_close(dev->cfs_dir_fd, "live", "0"); + return -1; + } + } + + dev->live = true; + + return 0; +} + +GPIOSIM_API int gpiosim_dev_disable(struct gpiosim_dev *dev) +{ + int ret; + + if (!dev_check_live(dev)) + return -1; + + ret = open_write_close(dev->cfs_dir_fd, "live", "0"); + if (ret) + return ret; + + dev_close_sysfs_dirs(dev); + + dev->live = false; + + return 0; +} + +static void bank_release(struct refcount *ref) +{ + struct gpiosim_bank *bank = container_of(ref, struct gpiosim_bank, + refcnt); + struct gpiosim_dev *dev = bank->dev; + unsigned int i; + char buf[64]; + + for (i = 0; i < bank->num_lines; i++) { + snprintf(buf, sizeof(buf), "line%u/hog", i); + unlinkat(bank->cfs_dir_fd, buf, AT_REMOVEDIR); + snprintf(buf, sizeof(buf), "line%u", i); + unlinkat(bank->cfs_dir_fd, buf, AT_REMOVEDIR); + } + + list_del(&bank->siblings); + unlinkat(dev->cfs_dir_fd, bank->item_name, AT_REMOVEDIR); + gpiosim_dev_unref(dev); + close(bank->cfs_dir_fd); + free(bank->item_name); + free(bank); +} + +GPIOSIM_API struct gpiosim_bank* +gpiosim_bank_new(struct gpiosim_dev *dev, const char *name) +{ + struct gpiosim_bank *bank; + int configfs_fd; + char *item_name; + + if (!dev_check_pending(dev)) + return NULL; + + item_name = configfs_make_item_name(dev->cfs_dir_fd, name); + if (!item_name) + return NULL; + + configfs_fd = openat(dev->cfs_dir_fd, item_name, O_RDONLY); + if (configfs_fd < 0) + goto err_unlink; + + bank = malloc(sizeof(*bank)); + if (!bank) + goto err_close_cfs; + + memset(bank, 0, sizeof(*bank)); + + refcount_init(&bank->refcnt, bank_release); + list_add(&bank->siblings, &dev->banks); + bank->cfs_dir_fd = configfs_fd; + bank->dev = gpiosim_dev_ref(dev); + bank->item_name = item_name; + + return bank; + +err_close_cfs: + close(configfs_fd); +err_unlink: + unlinkat(dev->cfs_dir_fd, item_name, AT_REMOVEDIR); + + return NULL; +} + +GPIOSIM_API struct gpiosim_bank *gpiosim_bank_ref(struct gpiosim_bank *bank) +{ + refcount_inc(&bank->refcnt); + + return bank; +} + +GPIOSIM_API void gpiosim_bank_unref(struct gpiosim_bank *bank) +{ + refcount_dec(&bank->refcnt); +} + +GPIOSIM_API const char *gpiosim_bank_get_chip_name(struct gpiosim_bank *bank) +{ + return bank->chip_name; +} + +GPIOSIM_API const char *gpiosim_bank_get_dev_path(struct gpiosim_bank *bank) +{ + return bank->dev_path; +} + +GPIOSIM_API int gpiosim_bank_set_label(struct gpiosim_bank *bank, + const char *label) +{ + if (!dev_check_pending(bank->dev)) + return -1; + + return open_write_close(bank->cfs_dir_fd, "label", label); +} + +GPIOSIM_API int gpiosim_bank_set_num_lines(struct gpiosim_bank *bank, + unsigned int num_lines) +{ + char buf[32]; + int ret; + + if (!dev_check_pending(bank->dev)) + return -1; + + snprintf(buf, sizeof(buf), "%u", num_lines); + + ret = open_write_close(bank->cfs_dir_fd, "num_lines", buf); + if (ret) + return -1; + + bank->num_lines = num_lines; + + return 0; +} + +/* + * Create a sub-directory under given bank's configfs directory. Do nothing + * if the directory exists and is writable. Mode is O_RDONLY. + */ +static int bank_mkdirat(struct gpiosim_bank *bank, const char *path) +{ + int ret; + + ret = faccessat(bank->cfs_dir_fd, path, W_OK, 0); + if (ret) { + if (errno == ENOENT) { + ret = mkdirat(bank->cfs_dir_fd, path, O_RDONLY); + if (ret) + return -1; + } else { + return -1; + } + } + + return 0; +} + +GPIOSIM_API int gpiosim_bank_set_line_name(struct gpiosim_bank *bank, + unsigned int offset, + const char *name) +{ + char buf[32]; + int ret, fd; + + if (!dev_check_pending(bank->dev)) + return -1; + + snprintf(buf, sizeof(buf), "line%u", offset); + + ret = bank_mkdirat(bank, buf); + if (ret) + return -1; + + fd = openat(bank->cfs_dir_fd, buf, O_RDONLY); + if (fd < 0) + return -1; + + ret = open_write_close(fd, "name", name ?: ""); + close(fd); + return ret; +} + +GPIOSIM_API int gpiosim_bank_hog_line(struct gpiosim_bank *bank, + unsigned int offset, + const char *name, int direction) +{ + char buf[64], *dir; + int ret, fd; + + switch (direction) { + case GPIOSIM_HOG_DIR_INPUT: + dir = "input"; + break; + case GPIOSIM_HOG_DIR_OUTPUT_HIGH: + dir = "output-high"; + break; + case GPIOSIM_HOG_DIR_OUTPUT_LOW: + dir = "output-low"; + break; + default: + return -EINVAL; + } + + if (!dev_check_pending(bank->dev)) + return -1; + + snprintf(buf, sizeof(buf), "line%u", offset); + + ret = bank_mkdirat(bank, buf); + if (ret) + return -1; + + snprintf(buf, sizeof(buf), "line%u/hog", offset); + + ret = bank_mkdirat(bank, buf); + if (ret) + return -1; + + fd = openat(bank->cfs_dir_fd, buf, O_RDONLY); + if (fd < 0) + return -1; + + ret = open_write_close(fd, "name", name ?: ""); + if (ret) { + close(fd); + return -1; + } + + ret = open_write_close(fd, "direction", dir); + close(fd); + return ret; +} + +GPIOSIM_API int gpiosim_bank_clear_hog(struct gpiosim_bank *bank, + unsigned int offset) +{ + char buf[64]; + + snprintf(buf, sizeof(buf), "line%u/hog", offset); + + return unlinkat(bank->cfs_dir_fd, buf, AT_REMOVEDIR); +} + +static int sysfs_read_bank_attr(struct gpiosim_bank *bank, unsigned int offset, + const char *attr, char *buf, + unsigned int bufsize) +{ + struct gpiosim_dev *dev = bank->dev; + char where[32]; + + if (!dev_check_live(dev)) + return -1; + + snprintf(where, sizeof(where), "sim_gpio%u/%s", offset, attr); + + return open_read_close(bank->sysfs_dir_fd, where, buf, bufsize); +} + +GPIOSIM_API int gpiosim_bank_get_value(struct gpiosim_bank *bank, + unsigned int offset) +{ + char what[3]; + int ret; + + ret = sysfs_read_bank_attr(bank, offset, "value", what, sizeof(what)); + if (ret) + return ret; + + if (what[0] == '0') + return 0; + if (what[0] == '1') + return 1; + + errno = EIO; + return -1; +} + +GPIOSIM_API int gpiosim_bank_get_pull(struct gpiosim_bank *bank, + unsigned int offset) +{ + char what[16]; + int ret; + + ret = sysfs_read_bank_attr(bank, offset, "pull", what, sizeof(what)); + if (ret) + return ret; + + if (strcmp(what, "pull-down") == 0) + return GPIOSIM_PULL_DOWN; + if (strcmp(what, "pull-up") == 0) + return GPIOSIM_PULL_UP; + + errno = EIO; + return -1; +} + +GPIOSIM_API int gpiosim_bank_set_pull(struct gpiosim_bank *bank, + unsigned int offset, int pull) +{ + struct gpiosim_dev *dev = bank->dev; + char where[32], what[16]; + + if (!dev_check_live(dev)) + return -1; + + if (pull != GPIOSIM_PULL_DOWN && pull != GPIOSIM_PULL_UP) { + errno = EINVAL; + return -1; + } + + snprintf(where, sizeof(where), "sim_gpio%u/pull", offset); + snprintf(what, sizeof(what), + pull == GPIOSIM_PULL_DOWN ? "pull-down" : "pull-up"); + + return open_write_close(bank->sysfs_dir_fd, where, what); +} diff --git a/tests/gpiosim/gpiosim.h b/tests/gpiosim/gpiosim.h new file mode 100644 index 0000000..6cb71de --- /dev/null +++ b/tests/gpiosim/gpiosim.h @@ -0,0 +1,64 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ +/* SPDX-FileCopyrightText: 2021-2022 Bartosz Golaszewski */ + +#ifndef __GPIOD_GPIOSIM_H__ +#define __GPIOD_GPIOSIM_H__ + +#ifdef __cplusplus +extern "C" { +#endif + +struct gpiosim_ctx; +struct gpiosim_dev; +struct gpiosim_bank; + +enum { + GPIOSIM_PULL_DOWN = 1, + GPIOSIM_PULL_UP, +}; + +enum { + GPIOSIM_HOG_DIR_INPUT = 1, + GPIOSIM_HOG_DIR_OUTPUT_HIGH, + GPIOSIM_HOG_DIR_OUTPUT_LOW, +}; + +struct gpiosim_ctx *gpiosim_ctx_new(void); +struct gpiosim_ctx *gpiosim_ctx_ref(struct gpiosim_ctx *ctx); +void gpiosim_ctx_unref(struct gpiosim_ctx *ctx); + +struct gpiosim_dev * +gpiosim_dev_new(struct gpiosim_ctx *ctx, const char *name); +struct gpiosim_dev *gpiosim_dev_ref(struct gpiosim_dev *dev); +void gpiosim_dev_unref(struct gpiosim_dev *dev); +const char *gpiosim_dev_get_name(struct gpiosim_dev *dev); + +int gpiosim_dev_enable(struct gpiosim_dev *dev); +int gpiosim_dev_disable(struct gpiosim_dev *dev); + +struct gpiosim_bank* +gpiosim_bank_new(struct gpiosim_dev *dev, const char *name); +struct gpiosim_bank *gpiosim_bank_ref(struct gpiosim_bank *bank); +void gpiosim_bank_unref(struct gpiosim_bank *bank); +const char *gpiosim_bank_get_chip_name(struct gpiosim_bank *bank); +const char *gpiosim_bank_get_dev_path(struct gpiosim_bank *bank); + +int gpiosim_bank_set_label(struct gpiosim_bank *bank, const char *label); +int gpiosim_bank_set_num_lines(struct gpiosim_bank *bank, + unsigned int num_lines); +int gpiosim_bank_set_line_name(struct gpiosim_bank *bank, + unsigned int offset, const char *name); +int gpiosim_bank_hog_line(struct gpiosim_bank *bank, unsigned int offset, + const char *name, int direction); +int gpiosim_bank_clear_hog(struct gpiosim_bank *bank, unsigned int offset); + +int gpiosim_bank_get_value(struct gpiosim_bank *bank, unsigned int offset); +int gpiosim_bank_get_pull(struct gpiosim_bank *bank, unsigned int offset); +int gpiosim_bank_set_pull(struct gpiosim_bank *bank, + unsigned int offset, int pull); + +#ifdef __cplusplus +} /* extern "C" */ +#endif + +#endif /* __GPIOD_GPIOSIM_H__ */