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