1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (c) 2011-2017, The Linux Foundation 4 */ 5 6 #include <linux/slab.h> 7 #include <linux/pm_runtime.h> 8 #include "slimbus.h" 9 10 /** 11 * slim_msg_response() - Deliver Message response received from a device to the 12 * framework. 13 * 14 * @ctrl: Controller handle 15 * @reply: Reply received from the device 16 * @len: Length of the reply 17 * @tid: Transaction ID received with which framework can associate reply. 18 * 19 * Called by controller to inform framework about the response received. 20 * This helps in making the API asynchronous, and controller-driver doesn't need 21 * to manage 1 more table other than the one managed by framework mapping TID 22 * with buffers 23 */ 24 void slim_msg_response(struct slim_controller *ctrl, u8 *reply, u8 tid, u8 len) 25 { 26 struct slim_msg_txn *txn; 27 struct slim_val_inf *msg; 28 unsigned long flags; 29 30 spin_lock_irqsave(&ctrl->txn_lock, flags); 31 txn = idr_find(&ctrl->tid_idr, tid); 32 spin_unlock_irqrestore(&ctrl->txn_lock, flags); 33 34 if (txn == NULL) 35 return; 36 37 msg = txn->msg; 38 if (msg == NULL || msg->rbuf == NULL) { 39 dev_err(ctrl->dev, "Got response to invalid TID:%d, len:%d\n", 40 tid, len); 41 return; 42 } 43 44 slim_free_txn_tid(ctrl, txn); 45 memcpy(msg->rbuf, reply, len); 46 if (txn->comp) 47 complete(txn->comp); 48 49 /* Remove runtime-pm vote now that response was received for TID txn */ 50 pm_runtime_mark_last_busy(ctrl->dev); 51 pm_runtime_put_autosuspend(ctrl->dev); 52 } 53 EXPORT_SYMBOL_GPL(slim_msg_response); 54 55 /** 56 * slim_alloc_txn_tid() - Allocate a tid to txn 57 * 58 * @ctrl: Controller handle 59 * @txn: transaction to be allocated with tid. 60 * 61 * Return: zero on success with valid txn->tid and error code on failures. 62 */ 63 int slim_alloc_txn_tid(struct slim_controller *ctrl, struct slim_msg_txn *txn) 64 { 65 unsigned long flags; 66 int ret = 0; 67 68 spin_lock_irqsave(&ctrl->txn_lock, flags); 69 ret = idr_alloc_cyclic(&ctrl->tid_idr, txn, 1, 70 SLIM_MAX_TIDS, GFP_ATOMIC); 71 if (ret < 0) { 72 spin_unlock_irqrestore(&ctrl->txn_lock, flags); 73 return ret; 74 } 75 txn->tid = ret; 76 spin_unlock_irqrestore(&ctrl->txn_lock, flags); 77 return 0; 78 } 79 EXPORT_SYMBOL_GPL(slim_alloc_txn_tid); 80 81 /** 82 * slim_free_txn_tid() - Free tid of txn 83 * 84 * @ctrl: Controller handle 85 * @txn: transaction whose tid should be freed 86 */ 87 void slim_free_txn_tid(struct slim_controller *ctrl, struct slim_msg_txn *txn) 88 { 89 unsigned long flags; 90 91 spin_lock_irqsave(&ctrl->txn_lock, flags); 92 idr_remove(&ctrl->tid_idr, txn->tid); 93 spin_unlock_irqrestore(&ctrl->txn_lock, flags); 94 } 95 EXPORT_SYMBOL_GPL(slim_free_txn_tid); 96 97 /** 98 * slim_do_transfer() - Process a SLIMbus-messaging transaction 99 * 100 * @ctrl: Controller handle 101 * @txn: Transaction to be sent over SLIMbus 102 * 103 * Called by controller to transmit messaging transactions not dealing with 104 * Interface/Value elements. (e.g. transmitting a message to assign logical 105 * address to a slave device 106 * 107 * Return: -ETIMEDOUT: If transmission of this message timed out 108 * (e.g. due to bus lines not being clocked or driven by controller) 109 */ 110 int slim_do_transfer(struct slim_controller *ctrl, struct slim_msg_txn *txn) 111 { 112 DECLARE_COMPLETION_ONSTACK(done); 113 bool need_tid = false, clk_pause_msg = false; 114 int ret; 115 unsigned long time_left; 116 117 /* 118 * do not vote for runtime-PM if the transactions are part of clock 119 * pause sequence 120 */ 121 if (ctrl->sched.clk_state == SLIM_CLK_ENTERING_PAUSE && 122 (txn->mt == SLIM_MSG_MT_CORE && 123 txn->mc >= SLIM_MSG_MC_BEGIN_RECONFIGURATION && 124 txn->mc <= SLIM_MSG_MC_RECONFIGURE_NOW)) 125 clk_pause_msg = true; 126 127 if (!clk_pause_msg) { 128 ret = pm_runtime_get_sync(ctrl->dev); 129 if (ctrl->sched.clk_state != SLIM_CLK_ACTIVE) { 130 dev_err(ctrl->dev, "ctrl wrong state:%d, ret:%d\n", 131 ctrl->sched.clk_state, ret); 132 goto slim_xfer_err; 133 } 134 } 135 /* Initialize tid to invalid value */ 136 txn->tid = 0; 137 need_tid = slim_tid_txn(txn->mt, txn->mc); 138 139 if (need_tid) { 140 ret = slim_alloc_txn_tid(ctrl, txn); 141 if (ret) 142 return ret; 143 144 if (!txn->msg->comp) 145 txn->comp = &done; 146 else 147 txn->comp = txn->comp; 148 } 149 150 ret = ctrl->xfer_msg(ctrl, txn); 151 152 if (!ret && need_tid && !txn->msg->comp) { 153 unsigned long ms = txn->rl + HZ; 154 155 time_left = wait_for_completion_timeout(txn->comp, 156 msecs_to_jiffies(ms)); 157 if (!time_left) { 158 ret = -ETIMEDOUT; 159 slim_free_txn_tid(ctrl, txn); 160 } 161 } 162 163 if (ret) 164 dev_err(ctrl->dev, "Tx:MT:0x%x, MC:0x%x, LA:0x%x failed:%d\n", 165 txn->mt, txn->mc, txn->la, ret); 166 167 slim_xfer_err: 168 if (!clk_pause_msg && (txn->tid == 0 || ret == -ETIMEDOUT)) { 169 /* 170 * remove runtime-pm vote if this was TX only, or 171 * if there was error during this transaction 172 */ 173 pm_runtime_mark_last_busy(ctrl->dev); 174 pm_runtime_put_autosuspend(ctrl->dev); 175 } 176 return ret; 177 } 178 EXPORT_SYMBOL_GPL(slim_do_transfer); 179 180 static int slim_val_inf_sanity(struct slim_controller *ctrl, 181 struct slim_val_inf *msg, u8 mc) 182 { 183 if (!msg || msg->num_bytes > 16 || 184 (msg->start_offset + msg->num_bytes) > 0xC00) 185 goto reterr; 186 switch (mc) { 187 case SLIM_MSG_MC_REQUEST_VALUE: 188 case SLIM_MSG_MC_REQUEST_INFORMATION: 189 if (msg->rbuf != NULL) 190 return 0; 191 break; 192 193 case SLIM_MSG_MC_CHANGE_VALUE: 194 case SLIM_MSG_MC_CLEAR_INFORMATION: 195 if (msg->wbuf != NULL) 196 return 0; 197 break; 198 199 case SLIM_MSG_MC_REQUEST_CHANGE_VALUE: 200 case SLIM_MSG_MC_REQUEST_CLEAR_INFORMATION: 201 if (msg->rbuf != NULL && msg->wbuf != NULL) 202 return 0; 203 break; 204 } 205 reterr: 206 if (msg) 207 dev_err(ctrl->dev, "Sanity check failed:msg:offset:0x%x, mc:%d\n", 208 msg->start_offset, mc); 209 return -EINVAL; 210 } 211 212 static u16 slim_slicesize(int code) 213 { 214 static const u8 sizetocode[16] = { 215 0, 1, 2, 3, 3, 4, 4, 5, 5, 5, 5, 6, 6, 6, 6, 7 216 }; 217 218 code = clamp(code, 1, (int)ARRAY_SIZE(sizetocode)); 219 220 return sizetocode[code - 1]; 221 } 222 223 /** 224 * slim_xfer_msg() - Transfer a value info message on slim device 225 * 226 * @sbdev: slim device to which this msg has to be transfered 227 * @msg: value info message pointer 228 * @mc: message code of the message 229 * 230 * Called by drivers which want to transfer a vlaue or info elements. 231 * 232 * Return: -ETIMEDOUT: If transmission of this message timed out 233 */ 234 int slim_xfer_msg(struct slim_device *sbdev, struct slim_val_inf *msg, 235 u8 mc) 236 { 237 DEFINE_SLIM_LDEST_TXN(txn_stack, mc, 6, sbdev->laddr, msg); 238 struct slim_msg_txn *txn = &txn_stack; 239 struct slim_controller *ctrl = sbdev->ctrl; 240 int ret; 241 u16 sl; 242 243 if (!ctrl) 244 return -EINVAL; 245 246 ret = slim_val_inf_sanity(ctrl, msg, mc); 247 if (ret) 248 return ret; 249 250 sl = slim_slicesize(msg->num_bytes); 251 252 dev_dbg(ctrl->dev, "SB xfer msg:os:%x, len:%d, MC:%x, sl:%x\n", 253 msg->start_offset, msg->num_bytes, mc, sl); 254 255 txn->ec = ((sl | (1 << 3)) | ((msg->start_offset & 0xFFF) << 4)); 256 257 switch (mc) { 258 case SLIM_MSG_MC_REQUEST_CHANGE_VALUE: 259 case SLIM_MSG_MC_CHANGE_VALUE: 260 case SLIM_MSG_MC_REQUEST_CLEAR_INFORMATION: 261 case SLIM_MSG_MC_CLEAR_INFORMATION: 262 txn->rl += msg->num_bytes; 263 break; 264 default: 265 break; 266 } 267 268 if (slim_tid_txn(txn->mt, txn->mc)) 269 txn->rl++; 270 271 return slim_do_transfer(ctrl, txn); 272 } 273 EXPORT_SYMBOL_GPL(slim_xfer_msg); 274 275 static void slim_fill_msg(struct slim_val_inf *msg, u32 addr, 276 size_t count, u8 *rbuf, u8 *wbuf) 277 { 278 msg->start_offset = addr; 279 msg->num_bytes = count; 280 msg->rbuf = rbuf; 281 msg->wbuf = wbuf; 282 msg->comp = NULL; 283 } 284 285 /** 286 * slim_read() - Read SLIMbus value element 287 * 288 * @sdev: client handle. 289 * @addr: address of value element to read. 290 * @count: number of bytes to read. Maximum bytes allowed are 16. 291 * @val: will return what the value element value was 292 * 293 * Return: -EINVAL for Invalid parameters, -ETIMEDOUT If transmission of 294 * this message timed out (e.g. due to bus lines not being clocked 295 * or driven by controller) 296 */ 297 int slim_read(struct slim_device *sdev, u32 addr, size_t count, u8 *val) 298 { 299 struct slim_val_inf msg; 300 301 slim_fill_msg(&msg, addr, count, val, NULL); 302 303 return slim_xfer_msg(sdev, &msg, SLIM_MSG_MC_REQUEST_VALUE); 304 } 305 EXPORT_SYMBOL_GPL(slim_read); 306 307 /** 308 * slim_readb() - Read byte from SLIMbus value element 309 * 310 * @sdev: client handle. 311 * @addr: address in the value element to read. 312 * 313 * Return: byte value of value element. 314 */ 315 int slim_readb(struct slim_device *sdev, u32 addr) 316 { 317 int ret; 318 u8 buf; 319 320 ret = slim_read(sdev, addr, 1, &buf); 321 if (ret < 0) 322 return ret; 323 else 324 return buf; 325 } 326 EXPORT_SYMBOL_GPL(slim_readb); 327 328 /** 329 * slim_write() - Write SLIMbus value element 330 * 331 * @sdev: client handle. 332 * @addr: address in the value element to write. 333 * @count: number of bytes to write. Maximum bytes allowed are 16. 334 * @val: value to write to value element 335 * 336 * Return: -EINVAL for Invalid parameters, -ETIMEDOUT If transmission of 337 * this message timed out (e.g. due to bus lines not being clocked 338 * or driven by controller) 339 */ 340 int slim_write(struct slim_device *sdev, u32 addr, size_t count, u8 *val) 341 { 342 struct slim_val_inf msg; 343 344 slim_fill_msg(&msg, addr, count, NULL, val); 345 346 return slim_xfer_msg(sdev, &msg, SLIM_MSG_MC_CHANGE_VALUE); 347 } 348 EXPORT_SYMBOL_GPL(slim_write); 349 350 /** 351 * slim_writeb() - Write byte to SLIMbus value element 352 * 353 * @sdev: client handle. 354 * @addr: address of value element to write. 355 * @value: value to write to value element 356 * 357 * Return: -EINVAL for Invalid parameters, -ETIMEDOUT If transmission of 358 * this message timed out (e.g. due to bus lines not being clocked 359 * or driven by controller) 360 * 361 */ 362 int slim_writeb(struct slim_device *sdev, u32 addr, u8 value) 363 { 364 return slim_write(sdev, addr, 1, &value); 365 } 366 EXPORT_SYMBOL_GPL(slim_writeb); 367