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