Alex Elder | 4ccb6b7 | 2014-10-28 19:36:00 -0500 | [diff] [blame] | 1 | /* |
| 2 | * Greybus protocol handling |
| 3 | * |
Alex Elder | d3d2bea | 2015-03-26 21:25:01 -0500 | [diff] [blame] | 4 | * Copyright 2014-2015 Google Inc. |
| 5 | * Copyright 2014-2015 Linaro Ltd. |
Alex Elder | 4ccb6b7 | 2014-10-28 19:36:00 -0500 | [diff] [blame] | 6 | * |
| 7 | * Released under the GPLv2 only. |
| 8 | */ |
| 9 | |
Greg Kroah-Hartman | 7422a1e | 2014-12-24 13:01:45 -0800 | [diff] [blame] | 10 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| 11 | |
Alex Elder | 4ccb6b7 | 2014-10-28 19:36:00 -0500 | [diff] [blame] | 12 | #include "greybus.h" |
| 13 | |
| 14 | /* Global list of registered protocols */ |
| 15 | static DEFINE_SPINLOCK(gb_protocols_lock); |
| 16 | static LIST_HEAD(gb_protocols); |
| 17 | |
| 18 | /* Caller must hold gb_protocols_lock */ |
Viresh Kumar | 8fd4658 | 2015-05-20 16:47:59 +0530 | [diff] [blame] | 19 | static struct gb_protocol *gb_protocol_find(u8 id, u8 major, u8 minor) |
Alex Elder | 4ccb6b7 | 2014-10-28 19:36:00 -0500 | [diff] [blame] | 20 | { |
| 21 | struct gb_protocol *protocol; |
| 22 | |
Alex Elder | dbb8894 | 2014-11-05 16:12:52 -0600 | [diff] [blame] | 23 | list_for_each_entry(protocol, &gb_protocols, links) { |
| 24 | if (protocol->id < id) |
| 25 | continue; |
| 26 | if (protocol->id > id) |
| 27 | break; |
| 28 | |
| 29 | if (protocol->major > major) |
| 30 | continue; |
| 31 | if (protocol->major < major) |
| 32 | break; |
| 33 | |
| 34 | if (protocol->minor > minor) |
| 35 | continue; |
| 36 | if (protocol->minor < minor) |
| 37 | break; |
| 38 | |
| 39 | return protocol; |
| 40 | } |
Alex Elder | 4ccb6b7 | 2014-10-28 19:36:00 -0500 | [diff] [blame] | 41 | return NULL; |
| 42 | } |
| 43 | |
Greg Kroah-Hartman | 12a5dfc | 2014-12-24 13:01:40 -0800 | [diff] [blame] | 44 | int __gb_protocol_register(struct gb_protocol *protocol, struct module *module) |
Alex Elder | 4ccb6b7 | 2014-10-28 19:36:00 -0500 | [diff] [blame] | 45 | { |
Alex Elder | 4ccb6b7 | 2014-10-28 19:36:00 -0500 | [diff] [blame] | 46 | struct gb_protocol *existing; |
Alex Elder | 19d03de | 2014-11-05 16:12:53 -0600 | [diff] [blame] | 47 | u8 id = protocol->id; |
| 48 | u8 major = protocol->major; |
| 49 | u8 minor = protocol->minor; |
Alex Elder | 4ccb6b7 | 2014-10-28 19:36:00 -0500 | [diff] [blame] | 50 | |
Greg Kroah-Hartman | 12a5dfc | 2014-12-24 13:01:40 -0800 | [diff] [blame] | 51 | protocol->owner = module; |
| 52 | |
Greg Kroah-Hartman | 6869eb5 | 2015-01-23 10:06:24 +0800 | [diff] [blame] | 53 | /* |
| 54 | * The protocols list is sorted first by protocol id (low to |
| 55 | * high), then by major version (high to low), and finally |
| 56 | * by minor version (high to low). Searching only by |
| 57 | * protocol id will produce the newest implemented version |
| 58 | * of the protocol. |
| 59 | */ |
Alex Elder | 4ccb6b7 | 2014-10-28 19:36:00 -0500 | [diff] [blame] | 60 | spin_lock_irq(&gb_protocols_lock); |
Alex Elder | 4ccb6b7 | 2014-10-28 19:36:00 -0500 | [diff] [blame] | 61 | |
Greg Kroah-Hartman | 6869eb5 | 2015-01-23 10:06:24 +0800 | [diff] [blame] | 62 | list_for_each_entry(existing, &gb_protocols, links) { |
| 63 | if (existing->id < id) |
| 64 | continue; |
| 65 | if (existing->id > id) |
| 66 | break; |
| 67 | |
| 68 | if (existing->major > major) |
| 69 | continue; |
| 70 | if (existing->major < major) |
| 71 | break; |
| 72 | |
| 73 | if (existing->minor > minor) |
| 74 | continue; |
| 75 | if (existing->minor < minor) |
| 76 | break; |
| 77 | |
| 78 | /* A matching protocol has already been registered */ |
Alex Elder | dbb8894 | 2014-11-05 16:12:52 -0600 | [diff] [blame] | 79 | spin_unlock_irq(&gb_protocols_lock); |
Greg Kroah-Hartman | 6869eb5 | 2015-01-23 10:06:24 +0800 | [diff] [blame] | 80 | |
Greg Kroah-Hartman | 7c7d5b9 | 2014-12-23 15:16:51 -0800 | [diff] [blame] | 81 | return -EEXIST; |
Alex Elder | 4ccb6b7 | 2014-10-28 19:36:00 -0500 | [diff] [blame] | 82 | } |
| 83 | |
Alex Elder | dbb8894 | 2014-11-05 16:12:52 -0600 | [diff] [blame] | 84 | /* |
| 85 | * We need to insert the protocol here, before the existing one |
| 86 | * (or before the head if we searched the whole list) |
| 87 | */ |
Greg Kroah-Hartman | c1a0a8f | 2015-01-23 10:05:58 +0800 | [diff] [blame] | 88 | list_add_tail(&protocol->links, &existing->links); |
Alex Elder | dbb8894 | 2014-11-05 16:12:52 -0600 | [diff] [blame] | 89 | spin_unlock_irq(&gb_protocols_lock); |
| 90 | |
Greg Kroah-Hartman | 7422a1e | 2014-12-24 13:01:45 -0800 | [diff] [blame] | 91 | pr_info("Registered %s protocol.\n", protocol->name); |
| 92 | |
Greg Kroah-Hartman | fb69cb5 | 2014-12-23 15:16:53 -0800 | [diff] [blame] | 93 | /* |
| 94 | * Go try to bind any unbound connections, as we have a |
| 95 | * new protocol in the system |
| 96 | */ |
| 97 | gb_bundle_bind_protocols(); |
| 98 | |
Greg Kroah-Hartman | 7c7d5b9 | 2014-12-23 15:16:51 -0800 | [diff] [blame] | 99 | return 0; |
Alex Elder | 4ccb6b7 | 2014-10-28 19:36:00 -0500 | [diff] [blame] | 100 | } |
Greg Kroah-Hartman | 12a5dfc | 2014-12-24 13:01:40 -0800 | [diff] [blame] | 101 | EXPORT_SYMBOL_GPL(__gb_protocol_register); |
Alex Elder | 4ccb6b7 | 2014-10-28 19:36:00 -0500 | [diff] [blame] | 102 | |
Alex Elder | 19d03de | 2014-11-05 16:12:53 -0600 | [diff] [blame] | 103 | /* |
| 104 | * De-register a previously registered protocol. |
| 105 | * |
| 106 | * XXX Currently this fails (and reports an error to the caller) if |
| 107 | * XXX the protocol is currently in use. We may want to forcefully |
| 108 | * XXX kill off a protocol and all its active users at some point. |
Viresh Kumar | 696e0cc | 2014-11-21 11:26:30 +0530 | [diff] [blame] | 109 | * XXX But I think that's better handled by quiescing modules that |
Alex Elder | 19d03de | 2014-11-05 16:12:53 -0600 | [diff] [blame] | 110 | * XXX have users and having those users drop their reference. |
| 111 | * |
| 112 | * Returns true if successful, false otherwise. |
| 113 | */ |
Greg Kroah-Hartman | 7c7d5b9 | 2014-12-23 15:16:51 -0800 | [diff] [blame] | 114 | int gb_protocol_deregister(struct gb_protocol *protocol) |
Alex Elder | 4ccb6b7 | 2014-10-28 19:36:00 -0500 | [diff] [blame] | 115 | { |
Alex Elder | dbb8894 | 2014-11-05 16:12:52 -0600 | [diff] [blame] | 116 | u8 protocol_count = 0; |
Alex Elder | 0e44765 | 2014-11-05 16:12:51 -0600 | [diff] [blame] | 117 | |
Greg Kroah-Hartman | 7c7d5b9 | 2014-12-23 15:16:51 -0800 | [diff] [blame] | 118 | if (!protocol) |
| 119 | return 0; |
| 120 | |
Alex Elder | 4ccb6b7 | 2014-10-28 19:36:00 -0500 | [diff] [blame] | 121 | spin_lock_irq(&gb_protocols_lock); |
Viresh Kumar | 8fd4658 | 2015-05-20 16:47:59 +0530 | [diff] [blame] | 122 | protocol = gb_protocol_find(protocol->id, protocol->major, |
| 123 | protocol->minor); |
Alex Elder | 0e44765 | 2014-11-05 16:12:51 -0600 | [diff] [blame] | 124 | if (protocol) { |
| 125 | protocol_count = protocol->count; |
| 126 | if (!protocol_count) |
| 127 | list_del(&protocol->links); |
| 128 | } |
Alex Elder | 4ccb6b7 | 2014-10-28 19:36:00 -0500 | [diff] [blame] | 129 | spin_unlock_irq(&gb_protocols_lock); |
Alex Elder | 4ccb6b7 | 2014-10-28 19:36:00 -0500 | [diff] [blame] | 130 | |
Greg Kroah-Hartman | 7422a1e | 2014-12-24 13:01:45 -0800 | [diff] [blame] | 131 | if (protocol) |
| 132 | pr_info("Deregistered %s protocol.\n", protocol->name); |
| 133 | |
Alex Elder | 0e44765 | 2014-11-05 16:12:51 -0600 | [diff] [blame] | 134 | return protocol && !protocol_count; |
Alex Elder | 4ccb6b7 | 2014-10-28 19:36:00 -0500 | [diff] [blame] | 135 | } |
Greg Kroah-Hartman | df469a9 | 2014-12-23 15:16:52 -0800 | [diff] [blame] | 136 | EXPORT_SYMBOL_GPL(gb_protocol_deregister); |
Alex Elder | 4ccb6b7 | 2014-10-28 19:36:00 -0500 | [diff] [blame] | 137 | |
Alex Elder | 0e44765 | 2014-11-05 16:12:51 -0600 | [diff] [blame] | 138 | /* Returns the requested protocol if available, or a null pointer */ |
| 139 | struct gb_protocol *gb_protocol_get(u8 id, u8 major, u8 minor) |
Alex Elder | 4ccb6b7 | 2014-10-28 19:36:00 -0500 | [diff] [blame] | 140 | { |
| 141 | struct gb_protocol *protocol; |
Alex Elder | 0e44765 | 2014-11-05 16:12:51 -0600 | [diff] [blame] | 142 | u8 protocol_count; |
Alex Elder | 4ccb6b7 | 2014-10-28 19:36:00 -0500 | [diff] [blame] | 143 | |
| 144 | spin_lock_irq(&gb_protocols_lock); |
Viresh Kumar | 8fd4658 | 2015-05-20 16:47:59 +0530 | [diff] [blame] | 145 | protocol = gb_protocol_find(id, major, minor); |
Alex Elder | 0e44765 | 2014-11-05 16:12:51 -0600 | [diff] [blame] | 146 | if (protocol) { |
Greg Kroah-Hartman | 12a5dfc | 2014-12-24 13:01:40 -0800 | [diff] [blame] | 147 | if (!try_module_get(protocol->owner)) { |
| 148 | protocol = NULL; |
| 149 | } else { |
| 150 | protocol_count = protocol->count; |
| 151 | if (protocol_count != U8_MAX) |
| 152 | protocol->count++; |
| 153 | } |
Alex Elder | 0e44765 | 2014-11-05 16:12:51 -0600 | [diff] [blame] | 154 | } |
Alex Elder | 4ccb6b7 | 2014-10-28 19:36:00 -0500 | [diff] [blame] | 155 | spin_unlock_irq(&gb_protocols_lock); |
Alex Elder | 4ccb6b7 | 2014-10-28 19:36:00 -0500 | [diff] [blame] | 156 | |
Alex Elder | 0e44765 | 2014-11-05 16:12:51 -0600 | [diff] [blame] | 157 | if (protocol) |
| 158 | WARN_ON(protocol_count == U8_MAX); |
| 159 | else |
| 160 | pr_err("protocol id %hhu version %hhu.%hhu not found\n", |
| 161 | id, major, minor); |
| 162 | |
| 163 | return protocol; |
Alex Elder | 4ccb6b7 | 2014-10-28 19:36:00 -0500 | [diff] [blame] | 164 | } |
| 165 | |
Viresh Kumar | 36e79de | 2015-01-21 18:12:36 +0530 | [diff] [blame] | 166 | int gb_protocol_get_version(struct gb_connection *connection, int type, |
| 167 | void *request, int request_size, |
| 168 | struct gb_protocol_version_response *response, |
| 169 | __u8 major) |
| 170 | { |
| 171 | int retval; |
| 172 | |
| 173 | retval = gb_operation_sync(connection, type, request, request_size, |
| 174 | response, sizeof(*response)); |
| 175 | if (retval) |
| 176 | return retval; |
| 177 | |
| 178 | if (response->major > major) { |
| 179 | dev_err(&connection->dev, |
| 180 | "unsupported major version (%hhu > %hhu)\n", |
| 181 | response->major, major); |
| 182 | return -ENOTSUPP; |
| 183 | } |
| 184 | |
| 185 | dev_dbg(&connection->dev, "version_major = %u version_minor = %u\n", |
| 186 | response->major, response->minor); |
| 187 | |
| 188 | return 0; |
| 189 | } |
| 190 | EXPORT_SYMBOL_GPL(gb_protocol_get_version); |
| 191 | |
Alex Elder | 0e44765 | 2014-11-05 16:12:51 -0600 | [diff] [blame] | 192 | void gb_protocol_put(struct gb_protocol *protocol) |
Alex Elder | 4ccb6b7 | 2014-10-28 19:36:00 -0500 | [diff] [blame] | 193 | { |
Alex Elder | d3d2bea | 2015-03-26 21:25:01 -0500 | [diff] [blame] | 194 | u8 id; |
Greg Kroah-Hartman | 23ad7bb | 2014-12-24 13:12:10 -0800 | [diff] [blame] | 195 | u8 major; |
| 196 | u8 minor; |
Alex Elder | 0e44765 | 2014-11-05 16:12:51 -0600 | [diff] [blame] | 197 | u8 protocol_count; |
Alex Elder | 4ccb6b7 | 2014-10-28 19:36:00 -0500 | [diff] [blame] | 198 | |
Greg Kroah-Hartman | 23ad7bb | 2014-12-24 13:12:10 -0800 | [diff] [blame] | 199 | if (!protocol) |
| 200 | return; |
| 201 | |
Alex Elder | d3d2bea | 2015-03-26 21:25:01 -0500 | [diff] [blame] | 202 | id = protocol->id; |
Greg Kroah-Hartman | 23ad7bb | 2014-12-24 13:12:10 -0800 | [diff] [blame] | 203 | major = protocol->major; |
| 204 | minor = protocol->minor; |
| 205 | |
Alex Elder | 4ccb6b7 | 2014-10-28 19:36:00 -0500 | [diff] [blame] | 206 | spin_lock_irq(&gb_protocols_lock); |
Viresh Kumar | 8fd4658 | 2015-05-20 16:47:59 +0530 | [diff] [blame] | 207 | protocol = gb_protocol_find(id, major, minor); |
Alex Elder | 0e44765 | 2014-11-05 16:12:51 -0600 | [diff] [blame] | 208 | if (protocol) { |
| 209 | protocol_count = protocol->count; |
| 210 | if (protocol_count) |
| 211 | protocol->count--; |
Greg Kroah-Hartman | 12a5dfc | 2014-12-24 13:01:40 -0800 | [diff] [blame] | 212 | module_put(protocol->owner); |
Alex Elder | 0e44765 | 2014-11-05 16:12:51 -0600 | [diff] [blame] | 213 | } |
Alex Elder | 4ccb6b7 | 2014-10-28 19:36:00 -0500 | [diff] [blame] | 214 | spin_unlock_irq(&gb_protocols_lock); |
Alex Elder | 0e44765 | 2014-11-05 16:12:51 -0600 | [diff] [blame] | 215 | if (protocol) |
| 216 | WARN_ON(!protocol_count); |
| 217 | else |
| 218 | pr_err("protocol id %hhu version %hhu.%hhu not found\n", |
Alex Elder | d3d2bea | 2015-03-26 21:25:01 -0500 | [diff] [blame] | 219 | id, major, minor); |
Alex Elder | 4ccb6b7 | 2014-10-28 19:36:00 -0500 | [diff] [blame] | 220 | } |