drivers/slimbus/messaging.c

   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);