Bjorn Andersson | 026dad4 | 2016-09-01 15:27:59 -0700 | [diff] [blame] | 1 | /* |
| 2 | * remote processor messaging bus |
| 3 | * |
| 4 | * Copyright (C) 2011 Texas Instruments, Inc. |
| 5 | * Copyright (C) 2011 Google, Inc. |
| 6 | * |
| 7 | * Ohad Ben-Cohen <ohad@wizery.com> |
| 8 | * Brian Swetland <swetland@google.com> |
| 9 | * |
| 10 | * This software is licensed under the terms of the GNU General Public |
| 11 | * License version 2, as published by the Free Software Foundation, and |
| 12 | * may be copied, distributed, and modified under those terms. |
| 13 | * |
| 14 | * This program is distributed in the hope that it will be useful, |
| 15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 17 | * GNU General Public License for more details. |
| 18 | */ |
| 19 | |
| 20 | #define pr_fmt(fmt) "%s: " fmt, __func__ |
| 21 | |
| 22 | #include <linux/kernel.h> |
| 23 | #include <linux/rpmsg.h> |
| 24 | |
Bjorn Andersson | 8b881c0 | 2016-09-01 15:28:02 -0700 | [diff] [blame^] | 25 | #include "rpmsg_internal.h" |
| 26 | |
Bjorn Andersson | 026dad4 | 2016-09-01 15:27:59 -0700 | [diff] [blame] | 27 | /** |
| 28 | * rpmsg_create_ept() - create a new rpmsg_endpoint |
| 29 | * @rpdev: rpmsg channel device |
| 30 | * @cb: rx callback handler |
| 31 | * @priv: private data for the driver's use |
| 32 | * @chinfo: channel_info with the local rpmsg address to bind with @cb |
| 33 | * |
| 34 | * Every rpmsg address in the system is bound to an rx callback (so when |
| 35 | * inbound messages arrive, they are dispatched by the rpmsg bus using the |
| 36 | * appropriate callback handler) by means of an rpmsg_endpoint struct. |
| 37 | * |
| 38 | * This function allows drivers to create such an endpoint, and by that, |
| 39 | * bind a callback, and possibly some private data too, to an rpmsg address |
| 40 | * (either one that is known in advance, or one that will be dynamically |
| 41 | * assigned for them). |
| 42 | * |
| 43 | * Simple rpmsg drivers need not call rpmsg_create_ept, because an endpoint |
| 44 | * is already created for them when they are probed by the rpmsg bus |
| 45 | * (using the rx callback provided when they registered to the rpmsg bus). |
| 46 | * |
| 47 | * So things should just work for simple drivers: they already have an |
| 48 | * endpoint, their rx callback is bound to their rpmsg address, and when |
| 49 | * relevant inbound messages arrive (i.e. messages which their dst address |
| 50 | * equals to the src address of their rpmsg channel), the driver's handler |
| 51 | * is invoked to process it. |
| 52 | * |
| 53 | * That said, more complicated drivers might do need to allocate |
| 54 | * additional rpmsg addresses, and bind them to different rx callbacks. |
| 55 | * To accomplish that, those drivers need to call this function. |
| 56 | * |
| 57 | * Drivers should provide their @rpdev channel (so the new endpoint would belong |
| 58 | * to the same remote processor their channel belongs to), an rx callback |
| 59 | * function, an optional private data (which is provided back when the |
| 60 | * rx callback is invoked), and an address they want to bind with the |
| 61 | * callback. If @addr is RPMSG_ADDR_ANY, then rpmsg_create_ept will |
| 62 | * dynamically assign them an available rpmsg address (drivers should have |
| 63 | * a very good reason why not to always use RPMSG_ADDR_ANY here). |
| 64 | * |
| 65 | * Returns a pointer to the endpoint on success, or NULL on error. |
| 66 | */ |
| 67 | struct rpmsg_endpoint *rpmsg_create_ept(struct rpmsg_device *rpdev, |
| 68 | rpmsg_rx_cb_t cb, void *priv, |
| 69 | struct rpmsg_channel_info chinfo) |
| 70 | { |
| 71 | return rpdev->ops->create_ept(rpdev, cb, priv, chinfo); |
| 72 | } |
| 73 | EXPORT_SYMBOL(rpmsg_create_ept); |
Bjorn Andersson | c9bd6f4 | 2016-09-01 15:28:01 -0700 | [diff] [blame] | 74 | |
| 75 | /** |
| 76 | * rpmsg_destroy_ept() - destroy an existing rpmsg endpoint |
| 77 | * @ept: endpoing to destroy |
| 78 | * |
| 79 | * Should be used by drivers to destroy an rpmsg endpoint previously |
| 80 | * created with rpmsg_create_ept(). |
| 81 | */ |
| 82 | void rpmsg_destroy_ept(struct rpmsg_endpoint *ept) |
| 83 | { |
| 84 | ept->ops->destroy_ept(ept); |
| 85 | } |
| 86 | EXPORT_SYMBOL(rpmsg_destroy_ept); |
| 87 | |
| 88 | /** |
| 89 | * rpmsg_send() - send a message across to the remote processor |
| 90 | * @ept: the rpmsg endpoint |
| 91 | * @data: payload of message |
| 92 | * @len: length of payload |
| 93 | * |
| 94 | * This function sends @data of length @len on the @ept endpoint. |
| 95 | * The message will be sent to the remote processor which the @ept |
| 96 | * endpoint belongs to, using @ept's address and its associated rpmsg |
| 97 | * device destination addresses. |
| 98 | * In case there are no TX buffers available, the function will block until |
| 99 | * one becomes available, or a timeout of 15 seconds elapses. When the latter |
| 100 | * happens, -ERESTARTSYS is returned. |
| 101 | * |
| 102 | * Can only be called from process context (for now). |
| 103 | * |
| 104 | * Returns 0 on success and an appropriate error value on failure. |
| 105 | */ |
| 106 | int rpmsg_send(struct rpmsg_endpoint *ept, void *data, int len) |
| 107 | { |
| 108 | return ept->ops->send(ept, data, len); |
| 109 | } |
| 110 | EXPORT_SYMBOL(rpmsg_send); |
| 111 | |
| 112 | /** |
| 113 | * rpmsg_sendto() - send a message across to the remote processor, specify dst |
| 114 | * @ept: the rpmsg endpoint |
| 115 | * @data: payload of message |
| 116 | * @len: length of payload |
| 117 | * @dst: destination address |
| 118 | * |
| 119 | * This function sends @data of length @len to the remote @dst address. |
| 120 | * The message will be sent to the remote processor which the @ept |
| 121 | * endpoint belongs to, using @ept's address as source. |
| 122 | * In case there are no TX buffers available, the function will block until |
| 123 | * one becomes available, or a timeout of 15 seconds elapses. When the latter |
| 124 | * happens, -ERESTARTSYS is returned. |
| 125 | * |
| 126 | * Can only be called from process context (for now). |
| 127 | * |
| 128 | * Returns 0 on success and an appropriate error value on failure. |
| 129 | */ |
| 130 | int rpmsg_sendto(struct rpmsg_endpoint *ept, void *data, int len, u32 dst) |
| 131 | { |
| 132 | return ept->ops->sendto(ept, data, len, dst); |
| 133 | } |
| 134 | EXPORT_SYMBOL(rpmsg_sendto); |
| 135 | |
| 136 | /** |
| 137 | * rpmsg_send_offchannel() - send a message using explicit src/dst addresses |
| 138 | * @ept: the rpmsg endpoint |
| 139 | * @src: source address |
| 140 | * @dst: destination address |
| 141 | * @data: payload of message |
| 142 | * @len: length of payload |
| 143 | * |
| 144 | * This function sends @data of length @len to the remote @dst address, |
| 145 | * and uses @src as the source address. |
| 146 | * The message will be sent to the remote processor which the @ept |
| 147 | * endpoint belongs to. |
| 148 | * In case there are no TX buffers available, the function will block until |
| 149 | * one becomes available, or a timeout of 15 seconds elapses. When the latter |
| 150 | * happens, -ERESTARTSYS is returned. |
| 151 | * |
| 152 | * Can only be called from process context (for now). |
| 153 | * |
| 154 | * Returns 0 on success and an appropriate error value on failure. |
| 155 | */ |
| 156 | int rpmsg_send_offchannel(struct rpmsg_endpoint *ept, u32 src, u32 dst, |
| 157 | void *data, int len) |
| 158 | { |
| 159 | return ept->ops->send_offchannel(ept, src, dst, data, len); |
| 160 | } |
| 161 | EXPORT_SYMBOL(rpmsg_send_offchannel); |
| 162 | |
| 163 | /** |
| 164 | * rpmsg_send() - send a message across to the remote processor |
| 165 | * @ept: the rpmsg endpoint |
| 166 | * @data: payload of message |
| 167 | * @len: length of payload |
| 168 | * |
| 169 | * This function sends @data of length @len on the @ept endpoint. |
| 170 | * The message will be sent to the remote processor which the @ept |
| 171 | * endpoint belongs to, using @ept's address as source and its associated |
| 172 | * rpdev's address as destination. |
| 173 | * In case there are no TX buffers available, the function will immediately |
| 174 | * return -ENOMEM without waiting until one becomes available. |
| 175 | * |
| 176 | * Can only be called from process context (for now). |
| 177 | * |
| 178 | * Returns 0 on success and an appropriate error value on failure. |
| 179 | */ |
| 180 | int rpmsg_trysend(struct rpmsg_endpoint *ept, void *data, int len) |
| 181 | { |
| 182 | return ept->ops->trysend(ept, data, len); |
| 183 | } |
| 184 | EXPORT_SYMBOL(rpmsg_trysend); |
| 185 | |
| 186 | /** |
| 187 | * rpmsg_sendto() - send a message across to the remote processor, specify dst |
| 188 | * @ept: the rpmsg endpoint |
| 189 | * @data: payload of message |
| 190 | * @len: length of payload |
| 191 | * @dst: destination address |
| 192 | * |
| 193 | * This function sends @data of length @len to the remote @dst address. |
| 194 | * The message will be sent to the remote processor which the @ept |
| 195 | * endpoint belongs to, using @ept's address as source. |
| 196 | * In case there are no TX buffers available, the function will immediately |
| 197 | * return -ENOMEM without waiting until one becomes available. |
| 198 | * |
| 199 | * Can only be called from process context (for now). |
| 200 | * |
| 201 | * Returns 0 on success and an appropriate error value on failure. |
| 202 | */ |
| 203 | int rpmsg_trysendto(struct rpmsg_endpoint *ept, void *data, int len, u32 dst) |
| 204 | { |
| 205 | return ept->ops->trysendto(ept, data, len, dst); |
| 206 | } |
| 207 | EXPORT_SYMBOL(rpmsg_trysendto); |
| 208 | |
| 209 | /** |
| 210 | * rpmsg_send_offchannel() - send a message using explicit src/dst addresses |
| 211 | * @ept: the rpmsg endpoint |
| 212 | * @src: source address |
| 213 | * @dst: destination address |
| 214 | * @data: payload of message |
| 215 | * @len: length of payload |
| 216 | * |
| 217 | * This function sends @data of length @len to the remote @dst address, |
| 218 | * and uses @src as the source address. |
| 219 | * The message will be sent to the remote processor which the @ept |
| 220 | * endpoint belongs to. |
| 221 | * In case there are no TX buffers available, the function will immediately |
| 222 | * return -ENOMEM without waiting until one becomes available. |
| 223 | * |
| 224 | * Can only be called from process context (for now). |
| 225 | * |
| 226 | * Returns 0 on success and an appropriate error value on failure. |
| 227 | */ |
| 228 | int rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept, u32 src, u32 dst, |
| 229 | void *data, int len) |
| 230 | { |
| 231 | return ept->ops->trysend_offchannel(ept, src, dst, data, len); |
| 232 | } |
| 233 | EXPORT_SYMBOL(rpmsg_trysend_offchannel); |
Bjorn Andersson | 8b881c0 | 2016-09-01 15:28:02 -0700 | [diff] [blame^] | 234 | |
| 235 | /* |
| 236 | * match an rpmsg channel with a channel info struct. |
| 237 | * this is used to make sure we're not creating rpmsg devices for channels |
| 238 | * that already exist. |
| 239 | */ |
| 240 | static int rpmsg_device_match(struct device *dev, void *data) |
| 241 | { |
| 242 | struct rpmsg_channel_info *chinfo = data; |
| 243 | struct rpmsg_device *rpdev = to_rpmsg_device(dev); |
| 244 | |
| 245 | if (chinfo->src != RPMSG_ADDR_ANY && chinfo->src != rpdev->src) |
| 246 | return 0; |
| 247 | |
| 248 | if (chinfo->dst != RPMSG_ADDR_ANY && chinfo->dst != rpdev->dst) |
| 249 | return 0; |
| 250 | |
| 251 | if (strncmp(chinfo->name, rpdev->id.name, RPMSG_NAME_SIZE)) |
| 252 | return 0; |
| 253 | |
| 254 | /* found a match ! */ |
| 255 | return 1; |
| 256 | } |
| 257 | |
| 258 | struct device *rpmsg_find_device(struct device *parent, |
| 259 | struct rpmsg_channel_info *chinfo) |
| 260 | { |
| 261 | return device_find_child(parent, chinfo, rpmsg_device_match); |
| 262 | |
| 263 | } |
| 264 | EXPORT_SYMBOL(rpmsg_find_device); |