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, id: tid); |
32 | spin_unlock_irqrestore(lock: &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(dev: ctrl->dev); |
51 | pm_runtime_put_autosuspend(dev: 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, ptr: txn, start: 1, |
70 | SLIM_MAX_TIDS, GFP_ATOMIC); |
71 | if (ret < 0) { |
72 | spin_unlock_irqrestore(lock: &ctrl->txn_lock, flags); |
73 | return ret; |
74 | } |
75 | txn->tid = ret; |
76 | spin_unlock_irqrestore(lock: &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, id: txn->tid); |
93 | spin_unlock_irqrestore(lock: &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, 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(dev: 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 | /* Initialize tid to invalid value */ |
135 | txn->tid = 0; |
136 | need_tid = slim_tid_txn(mt: txn->mt, mc: txn->mc); |
137 | |
138 | if (need_tid) { |
139 | ret = slim_alloc_txn_tid(ctrl, txn); |
140 | if (ret) |
141 | return ret; |
142 | |
143 | if (!txn->msg->comp) |
144 | txn->comp = &done; |
145 | else |
146 | txn->comp = txn->comp; |
147 | } |
148 | |
149 | ret = ctrl->xfer_msg(ctrl, txn); |
150 | |
151 | if (!ret && need_tid && !txn->msg->comp) { |
152 | unsigned long ms = txn->rl + HZ; |
153 | |
154 | timeout = wait_for_completion_timeout(x: txn->comp, |
155 | timeout: msecs_to_jiffies(m: ms)); |
156 | if (!timeout) { |
157 | ret = -ETIMEDOUT; |
158 | slim_free_txn_tid(ctrl, txn); |
159 | } |
160 | } |
161 | |
162 | if (ret) |
163 | dev_err(ctrl->dev, "Tx:MT:0x%x, MC:0x%x, LA:0x%x failed:%d\n" , |
164 | txn->mt, txn->mc, txn->la, ret); |
165 | |
166 | slim_xfer_err: |
167 | if (!clk_pause_msg && (txn->tid == 0 || ret == -ETIMEDOUT)) { |
168 | /* |
169 | * remove runtime-pm vote if this was TX only, or |
170 | * if there was error during this transaction |
171 | */ |
172 | pm_runtime_mark_last_busy(dev: ctrl->dev); |
173 | pm_runtime_put_autosuspend(dev: ctrl->dev); |
174 | } |
175 | return ret; |
176 | } |
177 | EXPORT_SYMBOL_GPL(slim_do_transfer); |
178 | |
179 | static int slim_val_inf_sanity(struct slim_controller *ctrl, |
180 | struct slim_val_inf *msg, u8 mc) |
181 | { |
182 | if (!msg || msg->num_bytes > 16 || |
183 | (msg->start_offset + msg->num_bytes) > 0xC00) |
184 | goto reterr; |
185 | switch (mc) { |
186 | case SLIM_MSG_MC_REQUEST_VALUE: |
187 | case SLIM_MSG_MC_REQUEST_INFORMATION: |
188 | if (msg->rbuf != NULL) |
189 | return 0; |
190 | break; |
191 | |
192 | case SLIM_MSG_MC_CHANGE_VALUE: |
193 | case SLIM_MSG_MC_CLEAR_INFORMATION: |
194 | if (msg->wbuf != NULL) |
195 | return 0; |
196 | break; |
197 | |
198 | case SLIM_MSG_MC_REQUEST_CHANGE_VALUE: |
199 | case SLIM_MSG_MC_REQUEST_CLEAR_INFORMATION: |
200 | if (msg->rbuf != NULL && msg->wbuf != NULL) |
201 | return 0; |
202 | break; |
203 | } |
204 | reterr: |
205 | if (msg) |
206 | dev_err(ctrl->dev, "Sanity check failed:msg:offset:0x%x, mc:%d\n" , |
207 | msg->start_offset, mc); |
208 | return -EINVAL; |
209 | } |
210 | |
211 | static u16 slim_slicesize(int code) |
212 | { |
213 | static const u8 sizetocode[16] = { |
214 | 0, 1, 2, 3, 3, 4, 4, 5, 5, 5, 5, 6, 6, 6, 6, 7 |
215 | }; |
216 | |
217 | code = clamp(code, 1, (int)ARRAY_SIZE(sizetocode)); |
218 | |
219 | return sizetocode[code - 1]; |
220 | } |
221 | |
222 | /** |
223 | * slim_xfer_msg() - Transfer a value info message on slim device |
224 | * |
225 | * @sbdev: slim device to which this msg has to be transfered |
226 | * @msg: value info message pointer |
227 | * @mc: message code of the message |
228 | * |
229 | * Called by drivers which want to transfer a vlaue or info elements. |
230 | * |
231 | * Return: -ETIMEDOUT: If transmission of this message timed out |
232 | */ |
233 | int slim_xfer_msg(struct slim_device *sbdev, struct slim_val_inf *msg, |
234 | u8 mc) |
235 | { |
236 | DEFINE_SLIM_LDEST_TXN(txn_stack, mc, 6, sbdev->laddr, msg); |
237 | struct slim_msg_txn *txn = &txn_stack; |
238 | struct slim_controller *ctrl = sbdev->ctrl; |
239 | int ret; |
240 | u16 sl; |
241 | |
242 | if (!ctrl) |
243 | return -EINVAL; |
244 | |
245 | ret = slim_val_inf_sanity(ctrl, msg, mc); |
246 | if (ret) |
247 | return ret; |
248 | |
249 | sl = slim_slicesize(code: msg->num_bytes); |
250 | |
251 | dev_dbg(ctrl->dev, "SB xfer msg:os:%x, len:%d, MC:%x, sl:%x\n" , |
252 | msg->start_offset, msg->num_bytes, mc, sl); |
253 | |
254 | txn->ec = ((sl | (1 << 3)) | ((msg->start_offset & 0xFFF) << 4)); |
255 | |
256 | switch (mc) { |
257 | case SLIM_MSG_MC_REQUEST_CHANGE_VALUE: |
258 | case SLIM_MSG_MC_CHANGE_VALUE: |
259 | case SLIM_MSG_MC_REQUEST_CLEAR_INFORMATION: |
260 | case SLIM_MSG_MC_CLEAR_INFORMATION: |
261 | txn->rl += msg->num_bytes; |
262 | break; |
263 | default: |
264 | break; |
265 | } |
266 | |
267 | if (slim_tid_txn(mt: txn->mt, mc: txn->mc)) |
268 | txn->rl++; |
269 | |
270 | return slim_do_transfer(ctrl, txn); |
271 | } |
272 | EXPORT_SYMBOL_GPL(slim_xfer_msg); |
273 | |
274 | static void slim_fill_msg(struct slim_val_inf *msg, u32 addr, |
275 | size_t count, u8 *rbuf, u8 *wbuf) |
276 | { |
277 | msg->start_offset = addr; |
278 | msg->num_bytes = count; |
279 | msg->rbuf = rbuf; |
280 | msg->wbuf = wbuf; |
281 | msg->comp = NULL; |
282 | } |
283 | |
284 | /** |
285 | * slim_read() - Read SLIMbus value element |
286 | * |
287 | * @sdev: client handle. |
288 | * @addr: address of value element to read. |
289 | * @count: number of bytes to read. Maximum bytes allowed are 16. |
290 | * @val: will return what the value element value was |
291 | * |
292 | * Return: -EINVAL for Invalid parameters, -ETIMEDOUT If transmission of |
293 | * this message timed out (e.g. due to bus lines not being clocked |
294 | * or driven by controller) |
295 | */ |
296 | int slim_read(struct slim_device *sdev, u32 addr, size_t count, u8 *val) |
297 | { |
298 | struct slim_val_inf msg; |
299 | |
300 | slim_fill_msg(msg: &msg, addr, count, rbuf: val, NULL); |
301 | |
302 | return slim_xfer_msg(sdev, &msg, SLIM_MSG_MC_REQUEST_VALUE); |
303 | } |
304 | EXPORT_SYMBOL_GPL(slim_read); |
305 | |
306 | /** |
307 | * slim_readb() - Read byte from SLIMbus value element |
308 | * |
309 | * @sdev: client handle. |
310 | * @addr: address in the value element to read. |
311 | * |
312 | * Return: byte value of value element. |
313 | */ |
314 | int slim_readb(struct slim_device *sdev, u32 addr) |
315 | { |
316 | int ret; |
317 | u8 buf; |
318 | |
319 | ret = slim_read(sdev, addr, 1, &buf); |
320 | if (ret < 0) |
321 | return ret; |
322 | else |
323 | return buf; |
324 | } |
325 | EXPORT_SYMBOL_GPL(slim_readb); |
326 | |
327 | /** |
328 | * slim_write() - Write SLIMbus value element |
329 | * |
330 | * @sdev: client handle. |
331 | * @addr: address in the value element to write. |
332 | * @count: number of bytes to write. Maximum bytes allowed are 16. |
333 | * @val: value to write to value element |
334 | * |
335 | * Return: -EINVAL for Invalid parameters, -ETIMEDOUT If transmission of |
336 | * this message timed out (e.g. due to bus lines not being clocked |
337 | * or driven by controller) |
338 | */ |
339 | int slim_write(struct slim_device *sdev, u32 addr, size_t count, u8 *val) |
340 | { |
341 | struct slim_val_inf msg; |
342 | |
343 | slim_fill_msg(msg: &msg, addr, count, NULL, wbuf: val); |
344 | |
345 | return slim_xfer_msg(sdev, &msg, SLIM_MSG_MC_CHANGE_VALUE); |
346 | } |
347 | EXPORT_SYMBOL_GPL(slim_write); |
348 | |
349 | /** |
350 | * slim_writeb() - Write byte to SLIMbus value element |
351 | * |
352 | * @sdev: client handle. |
353 | * @addr: address of value element to write. |
354 | * @value: value to write to value element |
355 | * |
356 | * Return: -EINVAL for Invalid parameters, -ETIMEDOUT If transmission of |
357 | * this message timed out (e.g. due to bus lines not being clocked |
358 | * or driven by controller) |
359 | * |
360 | */ |
361 | int slim_writeb(struct slim_device *sdev, u32 addr, u8 value) |
362 | { |
363 | return slim_write(sdev, addr, 1, &value); |
364 | } |
365 | EXPORT_SYMBOL_GPL(slim_writeb); |
366 | |