From mboxrd@z Thu Jan 1 00:00:00 1970 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 E56ACC433EF for ; Wed, 15 Dec 2021 13:42:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242951AbhLONms (ORCPT ); Wed, 15 Dec 2021 08:42:48 -0500 Received: from mga02.intel.com ([134.134.136.20]:34641 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242923AbhLONmk (ORCPT ); Wed, 15 Dec 2021 08:42:40 -0500 X-IronPort-AV: E=McAfee;i="6200,9189,10198"; a="226509039" X-IronPort-AV: E=Sophos;i="5.88,207,1635231600"; d="scan'208";a="226509039" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Dec 2021 05:42:40 -0800 X-IronPort-AV: E=Sophos;i="5.88,207,1635231600"; d="scan'208";a="518774324" Received: from cdobraun-mobl.ger.corp.intel.com (HELO tkristo-desk.intel.com) ([10.251.212.15]) by orsmga008-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Dec 2021 05:42:37 -0800 From: Tero Kristo To: linux-input@vger.kernel.org, benjamin.tissoires@redhat.com, jikos@kernel.org, tero.kristo@linux.intel.com Cc: linux-kernel@vger.kernel.org, dmitry.torokhov@gmail.com, peter.hutterer@who-t.net Subject: [RFCv5 2/2] samples: hid-bpf: add HID USI samples Date: Wed, 15 Dec 2021 15:42:20 +0200 Message-Id: <20211215134220.1735144-3-tero.kristo@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20211215134220.1735144-1-tero.kristo@linux.intel.com> References: <20211215134220.1735144-1-tero.kristo@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org These samples add HID USI client and server code. These are not compiled within kernel tree and are provided strictly as RFC only; the target for these is to build them external to the kernel tree. The provided samples run HID USI client-server communication over D-BUS. Signed-off-by: Tero Kristo --- samples/bpf/hid_usi.h | 21 ++ samples/bpf/hid_usi_client.c | 154 +++++++++++ samples/bpf/hid_usi_server.c | 438 ++++++++++++++++++++++++++++++ samples/bpf/hid_usi_server_kern.c | 267 ++++++++++++++++++ 4 files changed, 880 insertions(+) create mode 100644 samples/bpf/hid_usi.h create mode 100644 samples/bpf/hid_usi_client.c create mode 100644 samples/bpf/hid_usi_server.c create mode 100644 samples/bpf/hid_usi_server_kern.c diff --git a/samples/bpf/hid_usi.h b/samples/bpf/hid_usi.h new file mode 100644 index 000000000000..90803375d9c1 --- /dev/null +++ b/samples/bpf/hid_usi.h @@ -0,0 +1,21 @@ +/* SPDX-License-Identifier: GPL-2.0 + * + * Copyright(c) 2021 Intel Corporation. + */ + +#ifndef HID_USI_H_ +#define HID_USI_H_ + +#include + +enum { + USI_PEN_ID = 0, + USI_PEN_IN_RANGE, + USI_PEN_TOUCHING, + USI_PEN_COLOR, + USI_PEN_LINE_WIDTH, + USI_PEN_LINE_STYLE, + USI_NUM_PARAMS +}; + +#endif /* HID_USI_H */ diff --git a/samples/bpf/hid_usi_client.c b/samples/bpf/hid_usi_client.c new file mode 100644 index 000000000000..81a956798f62 --- /dev/null +++ b/samples/bpf/hid_usi_client.c @@ -0,0 +1,154 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2021, Intel Corporation + */ + +#include +#include +#include + +static void usi_var_get(GDBusProxy *proxy, const char *var) +{ + GVariant *result; + unsigned int val; + const GVariantType *type; + char *str; + + result = g_dbus_proxy_get_cached_property(proxy, var); + type = g_variant_get_type(result); + if (g_variant_type_equal(type, G_VARIANT_TYPE_UINT32)) { + g_variant_get(result, "u", &val); + printf("Value for %s (u): %u\n", var, val); + } else if (g_variant_type_equal(type, G_VARIANT_TYPE_STRING)) { + g_variant_get(result, "&s", &str); + printf("Value for %s (s): %s\n", var, str); + } else { + printf("Unsupported type %s for %s\n", + g_variant_get_type_string(result), var); + } + g_variant_unref(result); +} + +static void usi_dump_vars(GDBusProxy *proxy) +{ + gchar **vars; + int i; + + vars = g_dbus_proxy_get_cached_property_names(proxy); + + i = 0; + while (vars && vars[i]) { + usi_var_get(proxy, vars[i]); + i++; + } + + g_strfreev(vars); +} + +static void usi_var_set(GDBusProxy *proxy, const char *var, unsigned int value) +{ + GError *error = NULL; + + g_dbus_proxy_call_sync(proxy, + "org.freedesktop.DBus.Properties.Set", + g_variant_new("(su)", var, value), + G_DBUS_CALL_FLAGS_NONE, -1, NULL, &error); + + g_assert_no_error(error); +} + +static void usage(void) +{ + extern const char *__progname; + + printf("Usage: %s [--help] [--dump] [--color] [--width] [--style] [value]\n", + __progname); + + printf("\nOptions:\n"); + printf(" --help, -h this help text\n"); + printf(" --color [value] gets/sets stylus color\n"); + printf(" --width [value] gets/sets stylus line width\n"); + printf(" --style [value] gets/sets stylus line style\n"); + printf(" --dump dump all variables\n"); +} + +int main(int argc, char *argv[]) +{ + GDBusProxy *proxy; + GDBusConnection *conn; + GError *error = NULL; + const char *version; + GVariant *variant; + const char *var = NULL; + static struct option options[] = { + { "help", no_argument, NULL, 'h' }, + { "color", no_argument, NULL, 'c' }, + { "width", no_argument, NULL, 'w' }, + { "style", no_argument, NULL, 's' }, + { "dump", no_argument, NULL, 'd' }, + }; + int opt; + int retval = 0; + unsigned int value; + + conn = g_bus_get_sync(G_BUS_TYPE_SESSION, NULL, &error); + g_assert_no_error(error); + + proxy = g_dbus_proxy_new_sync(conn, + G_DBUS_PROXY_FLAGS_NONE, + NULL, /* GDBusInterfaceInfo */ + "org.universalstylus.PenServer", /* name */ + "/org/universalstylus/Pen", /* object path */ + "org.universalstylus.PenInterface", /* interface */ + NULL, /* GCancellable */ + &error); + g_assert_no_error(error); + + /* read the version property of the interface */ + variant = g_dbus_proxy_get_cached_property(proxy, "Version"); + g_assert(variant != NULL); + g_variant_get(variant, "s", &version); + g_variant_unref(variant); + printf("Server version v%s\n", version); + + while ((opt = getopt_long(argc, argv, "hcwsd", options, NULL)) != -1) { + switch (opt) { + case 'c': + var = "LineColor"; + break; + case 'w': + var = "LineWidth"; + break; + case 's': + var = "LineStyle"; + break; + case 'd': + usi_dump_vars(proxy); + goto exit; + + default: + usage(); + retval = EXIT_FAILURE; + goto exit; + } + } + + if (!var) { + usage(); + retval = EXIT_FAILURE; + goto exit; + } + if (argc == optind) { + usi_var_get(proxy, var); + } else if (argc == optind + 1) { + value = atoi(argv[argc - 1]); + usi_var_set(proxy, var, value); + } else { + usage(); + retval = EXIT_FAILURE; + } + +exit: + g_object_unref(proxy); + g_object_unref(conn); + return retval; +} diff --git a/samples/bpf/hid_usi_server.c b/samples/bpf/hid_usi_server.c new file mode 100644 index 000000000000..6d2012b018ac --- /dev/null +++ b/samples/bpf/hid_usi_server.c @@ -0,0 +1,438 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2021, Intel Corporation + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "bpf_util.h" +#include +#include + +#include + +#include "hid_usi.h" + +static const char *version = "0.5"; +static GMainLoop *mainloop; + +static char *sysfs_path; +static int sysfs_fd; +static int prog_count; +static int cache, wr_cache; + +static const struct option long_options[] = { + { "help", no_argument, NULL, 'h' }, +}; + +struct prog { + int fd; + enum bpf_attach_type type; +}; + +static struct prog progs[10]; + +static const char *server_introspection_xml = + DBUS_INTROSPECT_1_0_XML_DOCTYPE_DECL_NODE + "\n" + " \n" + " \n" + " \n" + " \n" + " \n" + + " \n" + " \n" + " \n" + " \n" + " \n" + " \n" + " \n" + " \n" + " \n" + " \n" + " \n" + " \n" + " \n" + + " \n" + " \n" + " \n" + " \n" + " \n" + " \n" + "\n"; + +static void int_exit(int sig) +{ + int ret; + + for (prog_count--; prog_count >= 0 ; prog_count--) { + ret = bpf_prog_detach2(progs[prog_count].fd, sysfs_fd, progs[prog_count].type); + if (ret) + fprintf(stderr, "bpf_prog_detach2: returned %m\n"); + } + + close(sysfs_fd); + exit(0); +} + +static void usage(const char *prog) +{ + fprintf(stderr, + "usage: %s /sys/bus/hid/devices//modalias\n\n", + prog); +} + +static int param_to_idx(const char *param) +{ + if (!strcmp(param, "LineColor")) + return USI_PEN_COLOR; + if (!strcmp(param, "LineWidth")) + return USI_PEN_LINE_WIDTH; + if (!strcmp(param, "LineStyle")) + return USI_PEN_LINE_STYLE; + + return -EINVAL; +} + +static int write_value(const char *param, int value) +{ + int err; + int idx = param_to_idx(param); + + printf("%s: param=%s (%d), value=%d\n", __func__, param, idx, value); + err = bpf_map_update_elem(wr_cache, &idx, &value, BPF_ANY); + if (err) { + printf("Update failed for %d, err=%d\n", idx, err); + return err; + } + + return 0; +} + +static int read_value(const char *param) +{ + int value = -ENOENT; + int idx = param_to_idx(param); + + bpf_map_lookup_elem(cache, &idx, &value); + + return value; +} + +static DBusHandlerResult usi_set_prop(DBusConnection *conn, DBusError *err, + DBusMessage *msg, DBusMessage *reply) +{ + const char *property; + unsigned int value; + int ret; + + if (!dbus_message_get_args(msg, err, + DBUS_TYPE_STRING, &property, + DBUS_TYPE_UINT32, &value, + DBUS_TYPE_INVALID)) + return -1; + + if (write_value(property, value) < 0) + return DBUS_HANDLER_RESULT_NOT_YET_HANDLED; + + return DBUS_HANDLER_RESULT_HANDLED; +} + +static DBusHandlerResult usi_get_prop(DBusConnection *conn, DBusError *err, + DBusMessage *msg, DBusMessage *reply) +{ + const char *property; + int value; + + if (!dbus_message_get_args(msg, err, + DBUS_TYPE_STRING, &property, + DBUS_TYPE_INVALID)) + return -1; + + if (!strcmp(property, "Version")) { + dbus_message_append_args(reply, + DBUS_TYPE_STRING, &version, + DBUS_TYPE_INVALID); + } else { + value = read_value(property); + if (value < 0) + return DBUS_HANDLER_RESULT_NOT_YET_HANDLED; + + dbus_message_append_args(reply, + DBUS_TYPE_UINT32, &value, + DBUS_TYPE_INVALID); + } + + return DBUS_HANDLER_RESULT_HANDLED; +} + +static DBusHandlerResult usi_get_all_props(DBusConnection *conn, DBusError *err, + DBusMessage *reply) +{ + DBusMessageIter array, dict, iter, variant; + const char *props[] = { + "Version", "LineColor", "LineWidth", "LineStyle" + }; + const char *types[] = { "s", "u", "u", "u" }; + int i; + unsigned int value; + void *ptr; + int itype; + + dbus_message_iter_init_append(reply, &iter); + dbus_message_iter_open_container(&iter, DBUS_TYPE_ARRAY, "{sv}", &array); + + for (i = 0; i < ARRAY_SIZE(props); i++) { + dbus_message_iter_open_container(&array, DBUS_TYPE_DICT_ENTRY, NULL, &dict); + dbus_message_iter_append_basic(&dict, DBUS_TYPE_STRING, &props[i]); + dbus_message_iter_open_container(&dict, DBUS_TYPE_VARIANT, types[i], &variant); + if (i == 0) { + ptr = &version; + itype = DBUS_TYPE_STRING; + } else { + value = read_value(props[i]); + ptr = &value; + itype = DBUS_TYPE_UINT32; + } + dbus_message_iter_append_basic(&variant, itype, ptr); + dbus_message_iter_close_container(&dict, &variant); + dbus_message_iter_close_container(&array, &dict); + } + + dbus_message_iter_close_container(&iter, &array); + + return DBUS_HANDLER_RESULT_HANDLED; +} + +static DBusHandlerResult usi_message_handler(DBusConnection *conn, + DBusMessage *message, void *data) +{ + DBusHandlerResult result = DBUS_HANDLER_RESULT_NOT_YET_HANDLED; + DBusMessage *reply; + DBusError err; + int value; + + fprintf(stderr, "Got D-Bus request: %s.%s on %s\n", + dbus_message_get_interface(message), + dbus_message_get_member(message), + dbus_message_get_path(message)); + + dbus_error_init(&err); + + reply = dbus_message_new_method_return(message); + if (!reply) + return DBUS_HANDLER_RESULT_NEED_MEMORY; + + if (dbus_message_is_method_call(message, DBUS_INTERFACE_INTROSPECTABLE, "Introspect")) { + dbus_message_append_args(reply, + DBUS_TYPE_STRING, &server_introspection_xml, + DBUS_TYPE_INVALID); + + } else if (dbus_message_is_method_call(message, DBUS_INTERFACE_PROPERTIES, "Get")) { + result = usi_get_prop(conn, &err, message, reply); + } else if (dbus_message_is_method_call(message, DBUS_INTERFACE_PROPERTIES, "GetAll")) { + result = usi_get_all_props(conn, &err, reply); + } else if (dbus_message_is_method_call(message, DBUS_INTERFACE_PROPERTIES, "Set")) { + result = usi_set_prop(conn, &err, message, reply); + } else { + dbus_message_unref(reply); + return DBUS_HANDLER_RESULT_NOT_YET_HANDLED; + } + + if (dbus_error_is_set(&err)) { + dbus_message_unref(reply); + + reply = dbus_message_new_error(message, err.name, err.message); + dbus_error_free(&err); + + if (!reply) + return DBUS_HANDLER_RESULT_NEED_MEMORY; + } + + result = DBUS_HANDLER_RESULT_HANDLED; + + if (!dbus_connection_send(conn, reply, NULL)) + result = DBUS_HANDLER_RESULT_NEED_MEMORY; + + dbus_message_unref(reply); + + return result; +} + +const DBusObjectPathVTable usi_vtable = { + .message_function = usi_message_handler, +}; + +static int server_run(void) +{ + DBusConnection *conn; + DBusError err; + int rv; + + dbus_error_init(&err); + + conn = dbus_bus_get(DBUS_BUS_SESSION, &err); + if (!conn) { + fprintf(stderr, "Failed to get a session DBus connection: %s\n", err.message); + goto fail; + } + + rv = dbus_bus_request_name(conn, "org.universalstylus.PenServer", + DBUS_NAME_FLAG_REPLACE_EXISTING, &err); + if (rv != DBUS_REQUEST_NAME_REPLY_PRIMARY_OWNER) { + fprintf(stderr, "Failed to request name on bus: %s\n", err.message); + goto fail; + } + + if (!dbus_connection_register_object_path(conn, + "/org/universalstylus/Pen", + &usi_vtable, NULL)) { + fprintf(stderr, "Failed to register a object path for 'Pen'\n"); + goto fail; + } + + printf("Starting dbus USI server v%s\n", version); + mainloop = g_main_loop_new(NULL, false); + dbus_connection_setup_with_g_main(conn, NULL); + g_main_loop_run(mainloop); + + return 0; +fail: + dbus_error_free(&err); + return -1; +} + +static int attach_progs(int argc, char **argv) +{ + char filename[256]; + struct bpf_prog_info info = {}; + __u32 info_len = sizeof(info); + struct bpf_object *obj; + struct bpf_program *prog; + int err = 0; + char buf[BUFSIZ]; + char param[16]; + char op[8]; + int value; + int m, n; + struct sockaddr_un addr; + struct sockaddr_un from; + socklen_t from_len = sizeof(from); + + snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]); + obj = bpf_object__open_file(filename, NULL); + err = libbpf_get_error(obj); + if (err) { + fprintf(stderr, "ERROR: opening BPF object file failed\n"); + obj = NULL; + err = 1; + goto cleanup; + } + + /* load BPF program */ + err = bpf_object__load(obj); + if (err) { + fprintf(stderr, "ERROR: loading BPF object file failed\n"); + goto cleanup; + } + + sysfs_fd = open(sysfs_path, O_RDONLY); + + bpf_object__for_each_program(prog, obj) { + progs[prog_count].fd = bpf_program__fd(prog); + progs[prog_count].type = bpf_program__get_expected_attach_type(prog); + + err = bpf_prog_attach(progs[prog_count].fd, + sysfs_fd, + progs[prog_count].type, + 0); + if (err) { + fprintf(stderr, "bpf_prog_attach: err=%m\n"); + progs[prog_count].fd = 0; + goto cleanup; + } + printf("attached BPF program with FD=%d, type=%d\n", + progs[prog_count].fd, progs[prog_count].type); + prog_count++; + } + + signal(SIGINT, int_exit); + signal(SIGTERM, int_exit); + + err = bpf_obj_get_info_by_fd(progs[0].fd, &info, &info_len); + if (err) { + printf("can't get prog info - %s\n", strerror(errno)); + goto cleanup; + } + + cache = bpf_object__find_map_fd_by_name(obj, "cache"); + if (cache < 0) { + printf("can't get 'cache' shared mem from object - %m\n"); + goto cleanup; + } + + wr_cache = bpf_object__find_map_fd_by_name(obj, "wr_cache"); + if (wr_cache < 0) { + printf("can't get 'wr_cache' shared mem from object - %m\n"); + goto cleanup; + } + + server_run(); + + return 0; + + cleanup: + for (prog_count--; prog_count >= 0; prog_count--) { + if (bpf_prog_detach2(progs[prog_count].fd, sysfs_fd, progs[prog_count].type)) + fprintf(stderr, "bpf_prog_detach2: returned %m\n"); + } + + bpf_object__close(obj); + return err; +} + +int main(int argc, char **argv) +{ + int opt; + + while ((opt = getopt_long(argc, argv, "h", long_options, + NULL)) != -1) { + switch (opt) { + default: + usage(basename(argv[0])); + return 1; + } + } + + if (optind == argc) { + usage(basename(argv[0])); + return 1; + } + + sysfs_path = argv[optind]; + if (!sysfs_path) { + perror("hidraw"); + return 1; + } + + printf("sysfs_path: %s\n", sysfs_path); + + return attach_progs(argc, argv); +} diff --git a/samples/bpf/hid_usi_server_kern.c b/samples/bpf/hid_usi_server_kern.c new file mode 100644 index 000000000000..3ecf638fb94d --- /dev/null +++ b/samples/bpf/hid_usi_server_kern.c @@ -0,0 +1,267 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright(c) 2021 Intel Corporation. */ +#include +#include +#include +#include +#include + +#include "hid_usi.h" + +#define MS_TO_JIFFIES(t) ((t) * HZ / 1000) + +static const char param_names[USI_NUM_PARAMS][6] = { + "id", + "range", + "touch", + "color", + "width", + "style", +}; + +struct { + __uint(type, BPF_MAP_TYPE_RINGBUF); + __uint(max_entries, 4096); +} ringbuf SEC(".maps"); + +struct { + __uint(type, BPF_MAP_TYPE_ARRAY); + __type(key, int); + __type(value, int); + __uint(max_entries, USI_NUM_PARAMS); +} cache SEC(".maps"); + +struct { + __uint(type, BPF_MAP_TYPE_ARRAY); + __type(key, int); + __type(value, int); + __uint(max_entries, USI_NUM_PARAMS); +} wr_cache SEC(".maps"); + +struct rep_data { + int offset; + int size; + int idx; +}; + +static struct rep_data inputs[USI_NUM_PARAMS]; +static struct rep_data features[USI_NUM_PARAMS]; +static bool work_pending; +static u64 last_pen_event; + +SEC("hid/work") +int hid_work(struct hid_bpf_ctx *ctx) +{ + int i, tmp; + int *wrc, *c; + u8 *buf; + bool have_work = false; + + for (i = USI_PEN_COLOR; i < USI_NUM_PARAMS; i++) { + tmp = i; + + wrc = bpf_map_lookup_elem(&wr_cache, &tmp); + c = bpf_map_lookup_elem(&cache, &tmp); + + if (!wrc || !c) + continue; + + if (*wrc == -1) + continue; + + if (*wrc != *c) { + bpf_printk("updating %s to %x", param_names[i], + *wrc); + buf = bpf_ringbuf_reserve(&ringbuf, 16, 0); + if (!buf) + continue; + + buf[0] = features[i].idx; + buf[1] = 1; + if (i == USI_PEN_LINE_STYLE && *wrc == 6) + buf[2] = 255; + else + buf[2] = *wrc; + + bpf_hid_raw_request(ctx, buf, 3, + HID_FEATURE_REPORT, + HID_REQ_SET_REPORT); + + bpf_ringbuf_discard(buf, 0); + + *c = *wrc; + + *wrc = -1; + + have_work = true; + break; + } + } + + if (have_work) + bpf_hid_schedule_work(ctx, MS_TO_JIFFIES(100)); + else + work_pending = false; + + return 0; +} + +SEC("hid/raw_event") +int hid_raw_event(struct hid_bpf_ctx *ctx) +{ + u32 i; + u32 tmp; + int val, new_val; + int *wrc, *c; + u8 *buf; + u32 flags = 0; + int offset; + int size; + int in_range; + int touching; + u64 jiffies; + + if (ctx->event.data[0] != inputs[USI_PEN_IN_RANGE].idx) + return 0; + + in_range = bpf_hid_get_data(ctx, inputs[USI_PEN_IN_RANGE].offset, + inputs[USI_PEN_IN_RANGE].size); + touching = bpf_hid_get_data(ctx, inputs[USI_PEN_TOUCHING].offset, + inputs[USI_PEN_TOUCHING].size); + + if (!touching) { + last_pen_event = 0; + return 0; + } + + jiffies = bpf_jiffies64(); + + if (!last_pen_event) + last_pen_event = jiffies; + + for (i = USI_PEN_COLOR; i < USI_NUM_PARAMS; i++) { + offset = inputs[i].offset; + size = inputs[i].size; + val = bpf_hid_get_data(ctx, offset, size); + + new_val = val; + if (i == USI_PEN_LINE_STYLE && new_val == 255) + new_val = 6; + + /* + * Make a local copy of 'i' which we can refer via a + * pointer to satisfy BPF verifier. + */ + tmp = i; + + wrc = bpf_map_lookup_elem(&wr_cache, &tmp); + c = bpf_map_lookup_elem(&cache, &tmp); + if (!wrc || !c) + continue; + + if (*wrc != -1 && *wrc != *c && !work_pending) { + bpf_hid_schedule_work(ctx, MS_TO_JIFFIES(200)); + work_pending = true; + } + + if (jiffies < last_pen_event + MS_TO_JIFFIES(200)) + *c = new_val; + + if (new_val != *c) + new_val = *c; + + if (new_val != val) + bpf_hid_set_data(ctx, offset, size, new_val); + } + + return 0; +} + +static void process_tag(struct hid_bpf_ctx *ctx, struct rep_data *data, + struct hid_bpf_parser *parser, u64 *idx) +{ + u32 i; + int id; + u32 offset; + + for (i = 0; i < parser->local.usage_index && i < 16; i++) { + offset = parser->report.current_offset + + i * parser->global.report_size; + + switch (parser->local.usage[i]) { + case HID_DG_PEN_COLOR: + id = USI_PEN_COLOR; + break; + case HID_DG_PEN_LINE_WIDTH: + id = USI_PEN_LINE_WIDTH; + break; + case HID_DG_PEN_LINE_STYLE_INK: + id = USI_PEN_LINE_STYLE; + break; + case HID_DG_INRANGE: + if (parser->local.usage_index == 1) + continue; + + id = USI_PEN_IN_RANGE; + break; + case HID_DG_TIPSWITCH: + if (parser->local.usage_index == 1) + continue; + + id = USI_PEN_TOUCHING; + break; + default: + continue; + } + + data[id].offset = offset + 8; + data[id].size = parser->global.report_size; + data[id].idx = parser->report.id; + + bpf_printk("parsed id=%d, offset=%d, idx=%d", + id, data[id].offset, data[id].idx); + } +} + +static u64 process_hid_rdesc_item(struct hid_bpf_ctx *ctx, + struct hid_bpf_parser *parser, u64 *idx, + void *data) +{ + struct hid_bpf_item *item = &parser->item; + + switch (item->type) { + case HID_ITEM_TYPE_MAIN: + if (item->tag == HID_MAIN_ITEM_TAG_INPUT) + process_tag(ctx, inputs, parser, idx); + if (item->tag == HID_MAIN_ITEM_TAG_FEATURE) + process_tag(ctx, features, parser, idx); + } + + return 0; +} + +SEC("hid/rdesc_fixup") +int hid_rdesc_fixup(struct hid_bpf_ctx *ctx) +{ + int ret; + int *wrc; + int i, tmp; + + if (ctx->type != HID_BPF_RDESC_FIXUP) + return 0; + + ret = bpf_hid_foreach_rdesc_item(ctx, process_hid_rdesc_item, (void *)0, 0); + for (i = USI_PEN_COLOR; i < USI_NUM_PARAMS; i++) { + tmp = i; + wrc = bpf_map_lookup_elem(&wr_cache, &tmp); + if (!wrc) + continue; + *wrc = -1; + } + + bpf_printk("ret: %d", ret); + return 0; +} + +char _license[] SEC("license") = "GPL"; +u32 _version SEC("version") = LINUX_VERSION_CODE; -- 2.25.1