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, 0, 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() - Freee 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. transmittting 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, timeout; 115 116 /* 117 * do not vote for runtime-PM if the transactions are part of clock 118 * pause sequence 119 */ 120 if (ctrl->sched.clk_state == SLIM_CLK_ENTERING_PAUSE && 121 (txn->mt == SLIM_MSG_MT_CORE && 122 txn->mc >= SLIM_MSG_MC_BEGIN_RECONFIGURATION && 123 txn->mc <= SLIM_MSG_MC_RECONFIGURE_NOW)) 124 clk_pause_msg = true; 125 126 if (!clk_pause_msg) { 127 ret = pm_runtime_get_sync(ctrl->dev); 128 if (ctrl->sched.clk_state != SLIM_CLK_ACTIVE) { 129 dev_err(ctrl->dev, "ctrl wrong state:%d, ret:%d\n", 130 ctrl->sched.clk_state, ret); 131 goto slim_xfer_err; 132 } 133 } 134 135 need_tid = slim_tid_txn(txn->mt, txn->mc); 136 137 if (need_tid) { 138 ret = slim_alloc_txn_tid(ctrl, txn); 139 if (ret) 140 return ret; 141 142 if (!txn->msg->comp) 143 txn->comp = &done; 144 else 145 txn->comp = txn->comp; 146 } 147 148 ret = ctrl->xfer_msg(ctrl, txn); 149 150 if (!ret && need_tid && !txn->msg->comp) { 151 unsigned long ms = txn->rl + HZ; 152 153 timeout = wait_for_completion_timeout(txn->comp, 154 msecs_to_jiffies(ms)); 155 if (!timeout) { 156 ret = -ETIMEDOUT; 157 slim_free_txn_tid(ctrl, txn); 158 } 159 } 160 161 if (ret) 162 dev_err(ctrl->dev, "Tx:MT:0x%x, MC:0x%x, LA:0x%x failed:%d\n", 163 txn->mt, txn->mc, txn->la, ret); 164 165 slim_xfer_err: 166 if (!clk_pause_msg && (!need_tid || ret == -ETIMEDOUT)) { 167 /* 168 * remove runtime-pm vote if this was TX only, or 169 * if there was error during this transaction 170 */ 171 pm_runtime_mark_last_busy(ctrl->dev); 172 pm_runtime_put_autosuspend(ctrl->dev); 173 } 174 return ret; 175 } 176 EXPORT_SYMBOL_GPL(slim_do_transfer); 177 178 static int slim_val_inf_sanity(struct slim_controller *ctrl, 179 struct slim_val_inf *msg, u8 mc) 180 { 181 if (!msg || msg->num_bytes > 16 || 182 (msg->start_offset + msg->num_bytes) > 0xC00) 183 goto reterr; 184 switch (mc) { 185 case SLIM_MSG_MC_REQUEST_VALUE: 186 case SLIM_MSG_MC_REQUEST_INFORMATION: 187 if (msg->rbuf != NULL) 188 return 0; 189 break; 190 191 case SLIM_MSG_MC_CHANGE_VALUE: 192 case SLIM_MSG_MC_CLEAR_INFORMATION: 193 if (msg->wbuf != NULL) 194 return 0; 195 break; 196 197 case SLIM_MSG_MC_REQUEST_CHANGE_VALUE: 198 case SLIM_MSG_MC_REQUEST_CLEAR_INFORMATION: 199 if (msg->rbuf != NULL && msg->wbuf != NULL) 200 return 0; 201 break; 202 } 203 reterr: 204 if (msg) 205 dev_err(ctrl->dev, "Sanity check failed:msg:offset:0x%x, mc:%d\n", 206 msg->start_offset, mc); 207 return -EINVAL; 208 } 209 210 static u16 slim_slicesize(int code) 211 { 212 static const u8 sizetocode[16] = { 213 0, 1, 2, 3, 3, 4, 4, 5, 5, 5, 5, 6, 6, 6, 6, 7 214 }; 215 216 code = clamp(code, 1, (int)ARRAY_SIZE(sizetocode)); 217 218 return sizetocode[code - 1]; 219 } 220 221 /** 222 * slim_xfer_msg() - Transfer a value info message on slim device 223 * 224 * @sbdev: slim device to which this msg has to be transfered 225 * @msg: value info message pointer 226 * @mc: message code of the message 227 * 228 * Called by drivers which want to transfer a vlaue or info elements. 229 * 230 * Return: -ETIMEDOUT: If transmission of this message timed out 231 */ 232 int slim_xfer_msg(struct slim_device *sbdev, struct slim_val_inf *msg, 233 u8 mc) 234 { 235 DEFINE_SLIM_LDEST_TXN(txn_stack, mc, 6, sbdev->laddr, msg); 236 struct slim_msg_txn *txn = &txn_stack; 237 struct slim_controller *ctrl = sbdev->ctrl; 238 int ret; 239 u16 sl; 240 241 if (!ctrl) 242 return -EINVAL; 243 244 ret = slim_val_inf_sanity(ctrl, msg, mc); 245 if (ret) 246 return ret; 247 248 sl = slim_slicesize(msg->num_bytes); 249 250 dev_dbg(ctrl->dev, "SB xfer msg:os:%x, len:%d, MC:%x, sl:%x\n", 251 msg->start_offset, msg->num_bytes, mc, sl); 252 253 txn->ec = ((sl | (1 << 3)) | ((msg->start_offset & 0xFFF) << 4)); 254 255 switch (mc) { 256 case SLIM_MSG_MC_REQUEST_CHANGE_VALUE: 257 case SLIM_MSG_MC_CHANGE_VALUE: 258 case SLIM_MSG_MC_REQUEST_CLEAR_INFORMATION: 259 case SLIM_MSG_MC_CLEAR_INFORMATION: 260 txn->rl += msg->num_bytes; 261 default: 262 break; 263 } 264 265 if (slim_tid_txn(txn->mt, txn->mc)) 266 txn->rl++; 267 268 return slim_do_transfer(ctrl, txn); 269 } 270 EXPORT_SYMBOL_GPL(slim_xfer_msg); 271 272 static void slim_fill_msg(struct slim_val_inf *msg, u32 addr, 273 size_t count, u8 *rbuf, u8 *wbuf) 274 { 275 msg->start_offset = addr; 276 msg->num_bytes = count; 277 msg->rbuf = rbuf; 278 msg->wbuf = wbuf; 279 msg->comp = NULL; 280 } 281 282 /** 283 * slim_read() - Read SLIMbus value element 284 * 285 * @sdev: client handle. 286 * @addr: address of value element to read. 287 * @count: number of bytes to read. Maximum bytes allowed are 16. 288 * @val: will return what the value element value was 289 * 290 * Return: -EINVAL for Invalid parameters, -ETIMEDOUT If transmission of 291 * this message timed out (e.g. due to bus lines not being clocked 292 * or driven by controller) 293 */ 294 int slim_read(struct slim_device *sdev, u32 addr, size_t count, u8 *val) 295 { 296 struct slim_val_inf msg; 297 298 slim_fill_msg(&msg, addr, count, val, NULL); 299 300 return slim_xfer_msg(sdev, &msg, SLIM_MSG_MC_REQUEST_VALUE); 301 } 302 EXPORT_SYMBOL_GPL(slim_read); 303 304 /** 305 * slim_readb() - Read byte from SLIMbus value element 306 * 307 * @sdev: client handle. 308 * @addr: address in the value element to read. 309 * 310 * Return: byte value of value element. 311 */ 312 int slim_readb(struct slim_device *sdev, u32 addr) 313 { 314 int ret; 315 u8 buf; 316 317 ret = slim_read(sdev, addr, 1, &buf); 318 if (ret < 0) 319 return ret; 320 else 321 return buf; 322 } 323 EXPORT_SYMBOL_GPL(slim_readb); 324 325 /** 326 * slim_write() - Write SLIMbus value element 327 * 328 * @sdev: client handle. 329 * @addr: address in the value element to write. 330 * @count: number of bytes to write. Maximum bytes allowed are 16. 331 * @val: value to write to value element 332 * 333 * Return: -EINVAL for Invalid parameters, -ETIMEDOUT If transmission of 334 * this message timed out (e.g. due to bus lines not being clocked 335 * or driven by controller) 336 */ 337 int slim_write(struct slim_device *sdev, u32 addr, size_t count, u8 *val) 338 { 339 struct slim_val_inf msg; 340 341 slim_fill_msg(&msg, addr, count, NULL, val); 342 343 return slim_xfer_msg(sdev, &msg, SLIM_MSG_MC_CHANGE_VALUE); 344 } 345 EXPORT_SYMBOL_GPL(slim_write); 346 347 /** 348 * slim_writeb() - Write byte to SLIMbus value element 349 * 350 * @sdev: client handle. 351 * @addr: address of value element to write. 352 * @value: value to write to value element 353 * 354 * Return: -EINVAL for Invalid parameters, -ETIMEDOUT If transmission of 355 * this message timed out (e.g. due to bus lines not being clocked 356 * or driven by controller) 357 * 358 */ 359 int slim_writeb(struct slim_device *sdev, u32 addr, u8 value) 360 { 361 return slim_write(sdev, addr, 1, &value); 362 } 363 EXPORT_SYMBOL_GPL(slim_writeb); 364