1 /*
2  * Copyright (c) 2012 Qualcomm Atheros, Inc.
3  *
4  * Permission to use, copy, modify, and/or distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include <linux/interrupt.h>
18 
19 #include "wil6210.h"
20 #include "trace.h"
21 
22 /**
23  * Theory of operation:
24  *
25  * There is ISR pseudo-cause register,
26  * dma_rgf->DMA_RGF.PSEUDO_CAUSE.PSEUDO_CAUSE
27  * Its bits represents OR'ed bits from 3 real ISR registers:
28  * TX, RX, and MISC.
29  *
30  * Registers may be configured to either "write 1 to clear" or
31  * "clear on read" mode
32  *
33  * When handling interrupt, one have to mask/unmask interrupts for the
34  * real ISR registers, or hardware may malfunction.
35  *
36  */
37 
38 #define WIL6210_IRQ_DISABLE	(0xFFFFFFFFUL)
39 #define WIL6210_IMC_RX		BIT_DMA_EP_RX_ICR_RX_DONE
40 #define WIL6210_IMC_TX		(BIT_DMA_EP_TX_ICR_TX_DONE | \
41 				BIT_DMA_EP_TX_ICR_TX_DONE_N(0))
42 #define WIL6210_IMC_MISC	(ISR_MISC_FW_READY | \
43 				 ISR_MISC_MBOX_EVT | \
44 				 ISR_MISC_FW_ERROR)
45 
46 #define WIL6210_IRQ_PSEUDO_MASK (u32)(~(BIT_DMA_PSEUDO_CAUSE_RX | \
47 					BIT_DMA_PSEUDO_CAUSE_TX | \
48 					BIT_DMA_PSEUDO_CAUSE_MISC))
49 
50 #if defined(CONFIG_WIL6210_ISR_COR)
51 /* configure to Clear-On-Read mode */
52 #define WIL_ICR_ICC_VALUE	(0xFFFFFFFFUL)
53 
54 static inline void wil_icr_clear(u32 x, void __iomem *addr)
55 {
56 }
57 #else /* defined(CONFIG_WIL6210_ISR_COR) */
58 /* configure to Write-1-to-Clear mode */
59 #define WIL_ICR_ICC_VALUE	(0UL)
60 
61 static inline void wil_icr_clear(u32 x, void __iomem *addr)
62 {
63 	iowrite32(x, addr);
64 }
65 #endif /* defined(CONFIG_WIL6210_ISR_COR) */
66 
67 static inline u32 wil_ioread32_and_clear(void __iomem *addr)
68 {
69 	u32 x = ioread32(addr);
70 
71 	wil_icr_clear(x, addr);
72 
73 	return x;
74 }
75 
76 static void wil6210_mask_irq_tx(struct wil6210_priv *wil)
77 {
78 	iowrite32(WIL6210_IRQ_DISABLE, wil->csr +
79 		  HOSTADDR(RGF_DMA_EP_TX_ICR) +
80 		  offsetof(struct RGF_ICR, IMS));
81 }
82 
83 static void wil6210_mask_irq_rx(struct wil6210_priv *wil)
84 {
85 	iowrite32(WIL6210_IRQ_DISABLE, wil->csr +
86 		  HOSTADDR(RGF_DMA_EP_RX_ICR) +
87 		  offsetof(struct RGF_ICR, IMS));
88 }
89 
90 static void wil6210_mask_irq_misc(struct wil6210_priv *wil)
91 {
92 	iowrite32(WIL6210_IRQ_DISABLE, wil->csr +
93 		  HOSTADDR(RGF_DMA_EP_MISC_ICR) +
94 		  offsetof(struct RGF_ICR, IMS));
95 }
96 
97 static void wil6210_mask_irq_pseudo(struct wil6210_priv *wil)
98 {
99 	wil_dbg_irq(wil, "%s()\n", __func__);
100 
101 	iowrite32(WIL6210_IRQ_DISABLE, wil->csr +
102 		  HOSTADDR(RGF_DMA_PSEUDO_CAUSE_MASK_SW));
103 
104 	clear_bit(wil_status_irqen, &wil->status);
105 }
106 
107 void wil6210_unmask_irq_tx(struct wil6210_priv *wil)
108 {
109 	iowrite32(WIL6210_IMC_TX, wil->csr +
110 		  HOSTADDR(RGF_DMA_EP_TX_ICR) +
111 		  offsetof(struct RGF_ICR, IMC));
112 }
113 
114 void wil6210_unmask_irq_rx(struct wil6210_priv *wil)
115 {
116 	iowrite32(WIL6210_IMC_RX, wil->csr +
117 		  HOSTADDR(RGF_DMA_EP_RX_ICR) +
118 		  offsetof(struct RGF_ICR, IMC));
119 }
120 
121 static void wil6210_unmask_irq_misc(struct wil6210_priv *wil)
122 {
123 	iowrite32(WIL6210_IMC_MISC, wil->csr +
124 		  HOSTADDR(RGF_DMA_EP_MISC_ICR) +
125 		  offsetof(struct RGF_ICR, IMC));
126 }
127 
128 static void wil6210_unmask_irq_pseudo(struct wil6210_priv *wil)
129 {
130 	wil_dbg_irq(wil, "%s()\n", __func__);
131 
132 	set_bit(wil_status_irqen, &wil->status);
133 
134 	iowrite32(WIL6210_IRQ_PSEUDO_MASK, wil->csr +
135 		  HOSTADDR(RGF_DMA_PSEUDO_CAUSE_MASK_SW));
136 }
137 
138 void wil6210_disable_irq(struct wil6210_priv *wil)
139 {
140 	wil_dbg_irq(wil, "%s()\n", __func__);
141 
142 	wil6210_mask_irq_tx(wil);
143 	wil6210_mask_irq_rx(wil);
144 	wil6210_mask_irq_misc(wil);
145 	wil6210_mask_irq_pseudo(wil);
146 }
147 
148 void wil6210_enable_irq(struct wil6210_priv *wil)
149 {
150 	wil_dbg_irq(wil, "%s()\n", __func__);
151 
152 	iowrite32(WIL_ICR_ICC_VALUE, wil->csr + HOSTADDR(RGF_DMA_EP_RX_ICR) +
153 		  offsetof(struct RGF_ICR, ICC));
154 	iowrite32(WIL_ICR_ICC_VALUE, wil->csr + HOSTADDR(RGF_DMA_EP_TX_ICR) +
155 		  offsetof(struct RGF_ICR, ICC));
156 	iowrite32(WIL_ICR_ICC_VALUE, wil->csr + HOSTADDR(RGF_DMA_EP_MISC_ICR) +
157 		  offsetof(struct RGF_ICR, ICC));
158 
159 	/* interrupt moderation parameters */
160 	if (wil->wdev->iftype == NL80211_IFTYPE_MONITOR) {
161 		/* disable interrupt moderation for monitor
162 		 * to get better timestamp precision
163 		 */
164 		iowrite32(0, wil->csr + HOSTADDR(RGF_DMA_ITR_CNT_CRL));
165 	} else {
166 		iowrite32(WIL6210_ITR_TRSH,
167 			  wil->csr + HOSTADDR(RGF_DMA_ITR_CNT_TRSH));
168 		iowrite32(BIT_DMA_ITR_CNT_CRL_EN,
169 			  wil->csr + HOSTADDR(RGF_DMA_ITR_CNT_CRL));
170 	}
171 
172 	wil6210_unmask_irq_pseudo(wil);
173 	wil6210_unmask_irq_tx(wil);
174 	wil6210_unmask_irq_rx(wil);
175 	wil6210_unmask_irq_misc(wil);
176 }
177 
178 static irqreturn_t wil6210_irq_rx(int irq, void *cookie)
179 {
180 	struct wil6210_priv *wil = cookie;
181 	u32 isr = wil_ioread32_and_clear(wil->csr +
182 					 HOSTADDR(RGF_DMA_EP_RX_ICR) +
183 					 offsetof(struct RGF_ICR, ICR));
184 
185 	trace_wil6210_irq_rx(isr);
186 	wil_dbg_irq(wil, "ISR RX 0x%08x\n", isr);
187 
188 	if (!isr) {
189 		wil_err(wil, "spurious IRQ: RX\n");
190 		return IRQ_NONE;
191 	}
192 
193 	wil6210_mask_irq_rx(wil);
194 
195 	if (isr & BIT_DMA_EP_RX_ICR_RX_DONE) {
196 		wil_dbg_irq(wil, "RX done\n");
197 		isr &= ~BIT_DMA_EP_RX_ICR_RX_DONE;
198 		wil_dbg_txrx(wil, "NAPI schedule\n");
199 		napi_schedule(&wil->napi_rx);
200 	}
201 
202 	if (isr)
203 		wil_err(wil, "un-handled RX ISR bits 0x%08x\n", isr);
204 
205 	/* Rx IRQ will be enabled when NAPI processing finished */
206 
207 	return IRQ_HANDLED;
208 }
209 
210 static irqreturn_t wil6210_irq_tx(int irq, void *cookie)
211 {
212 	struct wil6210_priv *wil = cookie;
213 	u32 isr = wil_ioread32_and_clear(wil->csr +
214 					 HOSTADDR(RGF_DMA_EP_TX_ICR) +
215 					 offsetof(struct RGF_ICR, ICR));
216 
217 	trace_wil6210_irq_tx(isr);
218 	wil_dbg_irq(wil, "ISR TX 0x%08x\n", isr);
219 
220 	if (!isr) {
221 		wil_err(wil, "spurious IRQ: TX\n");
222 		return IRQ_NONE;
223 	}
224 
225 	wil6210_mask_irq_tx(wil);
226 
227 	if (isr & BIT_DMA_EP_TX_ICR_TX_DONE) {
228 		wil_dbg_irq(wil, "TX done\n");
229 		napi_schedule(&wil->napi_tx);
230 		isr &= ~BIT_DMA_EP_TX_ICR_TX_DONE;
231 		/* clear also all VRING interrupts */
232 		isr &= ~(BIT(25) - 1UL);
233 	}
234 
235 	if (isr)
236 		wil_err(wil, "un-handled TX ISR bits 0x%08x\n", isr);
237 
238 	/* Tx IRQ will be enabled when NAPI processing finished */
239 
240 	return IRQ_HANDLED;
241 }
242 
243 static void wil_notify_fw_error(struct wil6210_priv *wil)
244 {
245 	struct device *dev = &wil_to_ndev(wil)->dev;
246 	char *envp[3] = {
247 		[0] = "SOURCE=wil6210",
248 		[1] = "EVENT=FW_ERROR",
249 		[2] = NULL,
250 	};
251 	kobject_uevent_env(&dev->kobj, KOBJ_CHANGE, envp);
252 }
253 
254 static void wil_cache_mbox_regs(struct wil6210_priv *wil)
255 {
256 	/* make shadow copy of registers that should not change on run time */
257 	wil_memcpy_fromio_32(&wil->mbox_ctl, wil->csr + HOST_MBOX,
258 			     sizeof(struct wil6210_mbox_ctl));
259 	wil_mbox_ring_le2cpus(&wil->mbox_ctl.rx);
260 	wil_mbox_ring_le2cpus(&wil->mbox_ctl.tx);
261 }
262 
263 static irqreturn_t wil6210_irq_misc(int irq, void *cookie)
264 {
265 	struct wil6210_priv *wil = cookie;
266 	u32 isr = wil_ioread32_and_clear(wil->csr +
267 					 HOSTADDR(RGF_DMA_EP_MISC_ICR) +
268 					 offsetof(struct RGF_ICR, ICR));
269 
270 	trace_wil6210_irq_misc(isr);
271 	wil_dbg_irq(wil, "ISR MISC 0x%08x\n", isr);
272 
273 	if (!isr) {
274 		wil_err(wil, "spurious IRQ: MISC\n");
275 		return IRQ_NONE;
276 	}
277 
278 	wil6210_mask_irq_misc(wil);
279 
280 	if (isr & ISR_MISC_FW_ERROR) {
281 		wil_err(wil, "Firmware error detected\n");
282 		clear_bit(wil_status_fwready, &wil->status);
283 		/*
284 		 * do not clear @isr here - we do 2-nd part in thread
285 		 * there, user space get notified, and it should be done
286 		 * in non-atomic context
287 		 */
288 	}
289 
290 	if (isr & ISR_MISC_FW_READY) {
291 		wil_dbg_irq(wil, "IRQ: FW ready\n");
292 		wil_cache_mbox_regs(wil);
293 		set_bit(wil_status_reset_done, &wil->status);
294 		/**
295 		 * Actual FW ready indicated by the
296 		 * WMI_FW_READY_EVENTID
297 		 */
298 		isr &= ~ISR_MISC_FW_READY;
299 	}
300 
301 	wil->isr_misc = isr;
302 
303 	if (isr) {
304 		return IRQ_WAKE_THREAD;
305 	} else {
306 		wil6210_unmask_irq_misc(wil);
307 		return IRQ_HANDLED;
308 	}
309 }
310 
311 static irqreturn_t wil6210_irq_misc_thread(int irq, void *cookie)
312 {
313 	struct wil6210_priv *wil = cookie;
314 	u32 isr = wil->isr_misc;
315 
316 	trace_wil6210_irq_misc_thread(isr);
317 	wil_dbg_irq(wil, "Thread ISR MISC 0x%08x\n", isr);
318 
319 	if (isr & ISR_MISC_FW_ERROR) {
320 		wil_notify_fw_error(wil);
321 		isr &= ~ISR_MISC_FW_ERROR;
322 	}
323 
324 	if (isr & ISR_MISC_MBOX_EVT) {
325 		wil_dbg_irq(wil, "MBOX event\n");
326 		wmi_recv_cmd(wil);
327 		isr &= ~ISR_MISC_MBOX_EVT;
328 	}
329 
330 	if (isr)
331 		wil_err(wil, "un-handled MISC ISR bits 0x%08x\n", isr);
332 
333 	wil->isr_misc = 0;
334 
335 	wil6210_unmask_irq_misc(wil);
336 
337 	return IRQ_HANDLED;
338 }
339 
340 /**
341  * thread IRQ handler
342  */
343 static irqreturn_t wil6210_thread_irq(int irq, void *cookie)
344 {
345 	struct wil6210_priv *wil = cookie;
346 
347 	wil_dbg_irq(wil, "Thread IRQ\n");
348 	/* Discover real IRQ cause */
349 	if (wil->isr_misc)
350 		wil6210_irq_misc_thread(irq, cookie);
351 
352 	wil6210_unmask_irq_pseudo(wil);
353 
354 	return IRQ_HANDLED;
355 }
356 
357 /* DEBUG
358  * There is subtle bug in hardware that causes IRQ to raise when it should be
359  * masked. It is quite rare and hard to debug.
360  *
361  * Catch irq issue if it happens and print all I can.
362  */
363 static int wil6210_debug_irq_mask(struct wil6210_priv *wil, u32 pseudo_cause)
364 {
365 	if (!test_bit(wil_status_irqen, &wil->status)) {
366 		u32 icm_rx = wil_ioread32_and_clear(wil->csr +
367 				HOSTADDR(RGF_DMA_EP_RX_ICR) +
368 				offsetof(struct RGF_ICR, ICM));
369 		u32 icr_rx = wil_ioread32_and_clear(wil->csr +
370 				HOSTADDR(RGF_DMA_EP_RX_ICR) +
371 				offsetof(struct RGF_ICR, ICR));
372 		u32 imv_rx = ioread32(wil->csr +
373 				HOSTADDR(RGF_DMA_EP_RX_ICR) +
374 				offsetof(struct RGF_ICR, IMV));
375 		u32 icm_tx = wil_ioread32_and_clear(wil->csr +
376 				HOSTADDR(RGF_DMA_EP_TX_ICR) +
377 				offsetof(struct RGF_ICR, ICM));
378 		u32 icr_tx = wil_ioread32_and_clear(wil->csr +
379 				HOSTADDR(RGF_DMA_EP_TX_ICR) +
380 				offsetof(struct RGF_ICR, ICR));
381 		u32 imv_tx = ioread32(wil->csr +
382 				HOSTADDR(RGF_DMA_EP_TX_ICR) +
383 				offsetof(struct RGF_ICR, IMV));
384 		u32 icm_misc = wil_ioread32_and_clear(wil->csr +
385 				HOSTADDR(RGF_DMA_EP_MISC_ICR) +
386 				offsetof(struct RGF_ICR, ICM));
387 		u32 icr_misc = wil_ioread32_and_clear(wil->csr +
388 				HOSTADDR(RGF_DMA_EP_MISC_ICR) +
389 				offsetof(struct RGF_ICR, ICR));
390 		u32 imv_misc = ioread32(wil->csr +
391 				HOSTADDR(RGF_DMA_EP_MISC_ICR) +
392 				offsetof(struct RGF_ICR, IMV));
393 		wil_err(wil, "IRQ when it should be masked: pseudo 0x%08x\n"
394 				"Rx   icm:icr:imv 0x%08x 0x%08x 0x%08x\n"
395 				"Tx   icm:icr:imv 0x%08x 0x%08x 0x%08x\n"
396 				"Misc icm:icr:imv 0x%08x 0x%08x 0x%08x\n",
397 				pseudo_cause,
398 				icm_rx, icr_rx, imv_rx,
399 				icm_tx, icr_tx, imv_tx,
400 				icm_misc, icr_misc, imv_misc);
401 
402 		return -EINVAL;
403 	}
404 
405 	return 0;
406 }
407 
408 static irqreturn_t wil6210_hardirq(int irq, void *cookie)
409 {
410 	irqreturn_t rc = IRQ_HANDLED;
411 	struct wil6210_priv *wil = cookie;
412 	u32 pseudo_cause = ioread32(wil->csr + HOSTADDR(RGF_DMA_PSEUDO_CAUSE));
413 
414 	/**
415 	 * pseudo_cause is Clear-On-Read, no need to ACK
416 	 */
417 	if ((pseudo_cause == 0) || ((pseudo_cause & 0xff) == 0xff))
418 		return IRQ_NONE;
419 
420 	/* FIXME: IRQ mask debug */
421 	if (wil6210_debug_irq_mask(wil, pseudo_cause))
422 		return IRQ_NONE;
423 
424 	trace_wil6210_irq_pseudo(pseudo_cause);
425 	wil_dbg_irq(wil, "Pseudo IRQ 0x%08x\n", pseudo_cause);
426 
427 	wil6210_mask_irq_pseudo(wil);
428 
429 	/* Discover real IRQ cause
430 	 * There are 2 possible phases for every IRQ:
431 	 * - hard IRQ handler called right here
432 	 * - threaded handler called later
433 	 *
434 	 * Hard IRQ handler reads and clears ISR.
435 	 *
436 	 * If threaded handler requested, hard IRQ handler
437 	 * returns IRQ_WAKE_THREAD and saves ISR register value
438 	 * for the threaded handler use.
439 	 *
440 	 * voting for wake thread - need at least 1 vote
441 	 */
442 	if ((pseudo_cause & BIT_DMA_PSEUDO_CAUSE_RX) &&
443 	    (wil6210_irq_rx(irq, cookie) == IRQ_WAKE_THREAD))
444 		rc = IRQ_WAKE_THREAD;
445 
446 	if ((pseudo_cause & BIT_DMA_PSEUDO_CAUSE_TX) &&
447 	    (wil6210_irq_tx(irq, cookie) == IRQ_WAKE_THREAD))
448 		rc = IRQ_WAKE_THREAD;
449 
450 	if ((pseudo_cause & BIT_DMA_PSEUDO_CAUSE_MISC) &&
451 	    (wil6210_irq_misc(irq, cookie) == IRQ_WAKE_THREAD))
452 		rc = IRQ_WAKE_THREAD;
453 
454 	/* if thread is requested, it will unmask IRQ */
455 	if (rc != IRQ_WAKE_THREAD)
456 		wil6210_unmask_irq_pseudo(wil);
457 
458 	return rc;
459 }
460 
461 static int wil6210_request_3msi(struct wil6210_priv *wil, int irq)
462 {
463 	int rc;
464 	/*
465 	 * IRQ's are in the following order:
466 	 * - Tx
467 	 * - Rx
468 	 * - Misc
469 	 */
470 
471 	rc = request_irq(irq, wil6210_irq_tx, IRQF_SHARED,
472 			 WIL_NAME"_tx", wil);
473 	if (rc)
474 		return rc;
475 
476 	rc = request_irq(irq + 1, wil6210_irq_rx, IRQF_SHARED,
477 			 WIL_NAME"_rx", wil);
478 	if (rc)
479 		goto free0;
480 
481 	rc = request_threaded_irq(irq + 2, wil6210_irq_misc,
482 				  wil6210_irq_misc_thread,
483 				  IRQF_SHARED, WIL_NAME"_misc", wil);
484 	if (rc)
485 		goto free1;
486 
487 	return 0;
488 	/* error branch */
489 free1:
490 	free_irq(irq + 1, wil);
491 free0:
492 	free_irq(irq, wil);
493 
494 	return rc;
495 }
496 
497 int wil6210_init_irq(struct wil6210_priv *wil, int irq)
498 {
499 	int rc;
500 	if (wil->n_msi == 3)
501 		rc = wil6210_request_3msi(wil, irq);
502 	else
503 		rc = request_threaded_irq(irq, wil6210_hardirq,
504 					  wil6210_thread_irq,
505 					  wil->n_msi ? 0 : IRQF_SHARED,
506 					  WIL_NAME, wil);
507 	if (rc)
508 		return rc;
509 
510 	wil6210_enable_irq(wil);
511 
512 	return 0;
513 }
514 
515 void wil6210_fini_irq(struct wil6210_priv *wil, int irq)
516 {
517 	wil6210_disable_irq(wil);
518 	free_irq(irq, wil);
519 	if (wil->n_msi == 3) {
520 		free_irq(irq + 1, wil);
521 		free_irq(irq + 2, wil);
522 	}
523 }
524