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 	wil6210_unmask_irq_pseudo(wil);
160 	wil6210_unmask_irq_tx(wil);
161 	wil6210_unmask_irq_rx(wil);
162 	wil6210_unmask_irq_misc(wil);
163 }
164 
165 static irqreturn_t wil6210_irq_rx(int irq, void *cookie)
166 {
167 	struct wil6210_priv *wil = cookie;
168 	u32 isr = wil_ioread32_and_clear(wil->csr +
169 					 HOSTADDR(RGF_DMA_EP_RX_ICR) +
170 					 offsetof(struct RGF_ICR, ICR));
171 
172 	trace_wil6210_irq_rx(isr);
173 	wil_dbg_irq(wil, "ISR RX 0x%08x\n", isr);
174 
175 	if (!isr) {
176 		wil_err(wil, "spurious IRQ: RX\n");
177 		return IRQ_NONE;
178 	}
179 
180 	wil6210_mask_irq_rx(wil);
181 
182 	if (isr & BIT_DMA_EP_RX_ICR_RX_DONE) {
183 		wil_dbg_irq(wil, "RX done\n");
184 		isr &= ~BIT_DMA_EP_RX_ICR_RX_DONE;
185 		wil_dbg_txrx(wil, "NAPI schedule\n");
186 		napi_schedule(&wil->napi_rx);
187 	}
188 
189 	if (isr)
190 		wil_err(wil, "un-handled RX ISR bits 0x%08x\n", isr);
191 
192 	/* Rx IRQ will be enabled when NAPI processing finished */
193 
194 	return IRQ_HANDLED;
195 }
196 
197 static irqreturn_t wil6210_irq_tx(int irq, void *cookie)
198 {
199 	struct wil6210_priv *wil = cookie;
200 	u32 isr = wil_ioread32_and_clear(wil->csr +
201 					 HOSTADDR(RGF_DMA_EP_TX_ICR) +
202 					 offsetof(struct RGF_ICR, ICR));
203 
204 	trace_wil6210_irq_tx(isr);
205 	wil_dbg_irq(wil, "ISR TX 0x%08x\n", isr);
206 
207 	if (!isr) {
208 		wil_err(wil, "spurious IRQ: TX\n");
209 		return IRQ_NONE;
210 	}
211 
212 	wil6210_mask_irq_tx(wil);
213 
214 	if (isr & BIT_DMA_EP_TX_ICR_TX_DONE) {
215 		wil_dbg_irq(wil, "TX done\n");
216 		napi_schedule(&wil->napi_tx);
217 		isr &= ~BIT_DMA_EP_TX_ICR_TX_DONE;
218 		/* clear also all VRING interrupts */
219 		isr &= ~(BIT(25) - 1UL);
220 	}
221 
222 	if (isr)
223 		wil_err(wil, "un-handled TX ISR bits 0x%08x\n", isr);
224 
225 	/* Tx IRQ will be enabled when NAPI processing finished */
226 
227 	return IRQ_HANDLED;
228 }
229 
230 static void wil_notify_fw_error(struct wil6210_priv *wil)
231 {
232 	struct device *dev = &wil_to_ndev(wil)->dev;
233 	char *envp[3] = {
234 		[0] = "SOURCE=wil6210",
235 		[1] = "EVENT=FW_ERROR",
236 		[2] = NULL,
237 	};
238 	kobject_uevent_env(&dev->kobj, KOBJ_CHANGE, envp);
239 }
240 
241 static void wil_cache_mbox_regs(struct wil6210_priv *wil)
242 {
243 	/* make shadow copy of registers that should not change on run time */
244 	wil_memcpy_fromio_32(&wil->mbox_ctl, wil->csr + HOST_MBOX,
245 			     sizeof(struct wil6210_mbox_ctl));
246 	wil_mbox_ring_le2cpus(&wil->mbox_ctl.rx);
247 	wil_mbox_ring_le2cpus(&wil->mbox_ctl.tx);
248 }
249 
250 static irqreturn_t wil6210_irq_misc(int irq, void *cookie)
251 {
252 	struct wil6210_priv *wil = cookie;
253 	u32 isr = wil_ioread32_and_clear(wil->csr +
254 					 HOSTADDR(RGF_DMA_EP_MISC_ICR) +
255 					 offsetof(struct RGF_ICR, ICR));
256 
257 	trace_wil6210_irq_misc(isr);
258 	wil_dbg_irq(wil, "ISR MISC 0x%08x\n", isr);
259 
260 	if (!isr) {
261 		wil_err(wil, "spurious IRQ: MISC\n");
262 		return IRQ_NONE;
263 	}
264 
265 	wil6210_mask_irq_misc(wil);
266 
267 	if (isr & ISR_MISC_FW_ERROR) {
268 		wil_err(wil, "Firmware error detected\n");
269 		clear_bit(wil_status_fwready, &wil->status);
270 		/*
271 		 * do not clear @isr here - we do 2-nd part in thread
272 		 * there, user space get notified, and it should be done
273 		 * in non-atomic context
274 		 */
275 	}
276 
277 	if (isr & ISR_MISC_FW_READY) {
278 		wil_dbg_irq(wil, "IRQ: FW ready\n");
279 		wil_cache_mbox_regs(wil);
280 		set_bit(wil_status_reset_done, &wil->status);
281 		/**
282 		 * Actual FW ready indicated by the
283 		 * WMI_FW_READY_EVENTID
284 		 */
285 		isr &= ~ISR_MISC_FW_READY;
286 	}
287 
288 	wil->isr_misc = isr;
289 
290 	if (isr) {
291 		return IRQ_WAKE_THREAD;
292 	} else {
293 		wil6210_unmask_irq_misc(wil);
294 		return IRQ_HANDLED;
295 	}
296 }
297 
298 static irqreturn_t wil6210_irq_misc_thread(int irq, void *cookie)
299 {
300 	struct wil6210_priv *wil = cookie;
301 	u32 isr = wil->isr_misc;
302 
303 	trace_wil6210_irq_misc_thread(isr);
304 	wil_dbg_irq(wil, "Thread ISR MISC 0x%08x\n", isr);
305 
306 	if (isr & ISR_MISC_FW_ERROR) {
307 		wil_notify_fw_error(wil);
308 		isr &= ~ISR_MISC_FW_ERROR;
309 	}
310 
311 	if (isr & ISR_MISC_MBOX_EVT) {
312 		wil_dbg_irq(wil, "MBOX event\n");
313 		wmi_recv_cmd(wil);
314 		isr &= ~ISR_MISC_MBOX_EVT;
315 	}
316 
317 	if (isr)
318 		wil_err(wil, "un-handled MISC ISR bits 0x%08x\n", isr);
319 
320 	wil->isr_misc = 0;
321 
322 	wil6210_unmask_irq_misc(wil);
323 
324 	return IRQ_HANDLED;
325 }
326 
327 /**
328  * thread IRQ handler
329  */
330 static irqreturn_t wil6210_thread_irq(int irq, void *cookie)
331 {
332 	struct wil6210_priv *wil = cookie;
333 
334 	wil_dbg_irq(wil, "Thread IRQ\n");
335 	/* Discover real IRQ cause */
336 	if (wil->isr_misc)
337 		wil6210_irq_misc_thread(irq, cookie);
338 
339 	wil6210_unmask_irq_pseudo(wil);
340 
341 	return IRQ_HANDLED;
342 }
343 
344 /* DEBUG
345  * There is subtle bug in hardware that causes IRQ to raise when it should be
346  * masked. It is quite rare and hard to debug.
347  *
348  * Catch irq issue if it happens and print all I can.
349  */
350 static int wil6210_debug_irq_mask(struct wil6210_priv *wil, u32 pseudo_cause)
351 {
352 	if (!test_bit(wil_status_irqen, &wil->status)) {
353 		u32 icm_rx = wil_ioread32_and_clear(wil->csr +
354 				HOSTADDR(RGF_DMA_EP_RX_ICR) +
355 				offsetof(struct RGF_ICR, ICM));
356 		u32 icr_rx = wil_ioread32_and_clear(wil->csr +
357 				HOSTADDR(RGF_DMA_EP_RX_ICR) +
358 				offsetof(struct RGF_ICR, ICR));
359 		u32 imv_rx = ioread32(wil->csr +
360 				HOSTADDR(RGF_DMA_EP_RX_ICR) +
361 				offsetof(struct RGF_ICR, IMV));
362 		u32 icm_tx = wil_ioread32_and_clear(wil->csr +
363 				HOSTADDR(RGF_DMA_EP_TX_ICR) +
364 				offsetof(struct RGF_ICR, ICM));
365 		u32 icr_tx = wil_ioread32_and_clear(wil->csr +
366 				HOSTADDR(RGF_DMA_EP_TX_ICR) +
367 				offsetof(struct RGF_ICR, ICR));
368 		u32 imv_tx = ioread32(wil->csr +
369 				HOSTADDR(RGF_DMA_EP_TX_ICR) +
370 				offsetof(struct RGF_ICR, IMV));
371 		u32 icm_misc = wil_ioread32_and_clear(wil->csr +
372 				HOSTADDR(RGF_DMA_EP_MISC_ICR) +
373 				offsetof(struct RGF_ICR, ICM));
374 		u32 icr_misc = wil_ioread32_and_clear(wil->csr +
375 				HOSTADDR(RGF_DMA_EP_MISC_ICR) +
376 				offsetof(struct RGF_ICR, ICR));
377 		u32 imv_misc = ioread32(wil->csr +
378 				HOSTADDR(RGF_DMA_EP_MISC_ICR) +
379 				offsetof(struct RGF_ICR, IMV));
380 		wil_err(wil, "IRQ when it should be masked: pseudo 0x%08x\n"
381 				"Rx   icm:icr:imv 0x%08x 0x%08x 0x%08x\n"
382 				"Tx   icm:icr:imv 0x%08x 0x%08x 0x%08x\n"
383 				"Misc icm:icr:imv 0x%08x 0x%08x 0x%08x\n",
384 				pseudo_cause,
385 				icm_rx, icr_rx, imv_rx,
386 				icm_tx, icr_tx, imv_tx,
387 				icm_misc, icr_misc, imv_misc);
388 
389 		return -EINVAL;
390 	}
391 
392 	return 0;
393 }
394 
395 static irqreturn_t wil6210_hardirq(int irq, void *cookie)
396 {
397 	irqreturn_t rc = IRQ_HANDLED;
398 	struct wil6210_priv *wil = cookie;
399 	u32 pseudo_cause = ioread32(wil->csr + HOSTADDR(RGF_DMA_PSEUDO_CAUSE));
400 
401 	/**
402 	 * pseudo_cause is Clear-On-Read, no need to ACK
403 	 */
404 	if ((pseudo_cause == 0) || ((pseudo_cause & 0xff) == 0xff))
405 		return IRQ_NONE;
406 
407 	/* FIXME: IRQ mask debug */
408 	if (wil6210_debug_irq_mask(wil, pseudo_cause))
409 		return IRQ_NONE;
410 
411 	trace_wil6210_irq_pseudo(pseudo_cause);
412 	wil_dbg_irq(wil, "Pseudo IRQ 0x%08x\n", pseudo_cause);
413 
414 	wil6210_mask_irq_pseudo(wil);
415 
416 	/* Discover real IRQ cause
417 	 * There are 2 possible phases for every IRQ:
418 	 * - hard IRQ handler called right here
419 	 * - threaded handler called later
420 	 *
421 	 * Hard IRQ handler reads and clears ISR.
422 	 *
423 	 * If threaded handler requested, hard IRQ handler
424 	 * returns IRQ_WAKE_THREAD and saves ISR register value
425 	 * for the threaded handler use.
426 	 *
427 	 * voting for wake thread - need at least 1 vote
428 	 */
429 	if ((pseudo_cause & BIT_DMA_PSEUDO_CAUSE_RX) &&
430 	    (wil6210_irq_rx(irq, cookie) == IRQ_WAKE_THREAD))
431 		rc = IRQ_WAKE_THREAD;
432 
433 	if ((pseudo_cause & BIT_DMA_PSEUDO_CAUSE_TX) &&
434 	    (wil6210_irq_tx(irq, cookie) == IRQ_WAKE_THREAD))
435 		rc = IRQ_WAKE_THREAD;
436 
437 	if ((pseudo_cause & BIT_DMA_PSEUDO_CAUSE_MISC) &&
438 	    (wil6210_irq_misc(irq, cookie) == IRQ_WAKE_THREAD))
439 		rc = IRQ_WAKE_THREAD;
440 
441 	/* if thread is requested, it will unmask IRQ */
442 	if (rc != IRQ_WAKE_THREAD)
443 		wil6210_unmask_irq_pseudo(wil);
444 
445 	return rc;
446 }
447 
448 static int wil6210_request_3msi(struct wil6210_priv *wil, int irq)
449 {
450 	int rc;
451 	/*
452 	 * IRQ's are in the following order:
453 	 * - Tx
454 	 * - Rx
455 	 * - Misc
456 	 */
457 
458 	rc = request_irq(irq, wil6210_irq_tx, IRQF_SHARED,
459 			 WIL_NAME"_tx", wil);
460 	if (rc)
461 		return rc;
462 
463 	rc = request_irq(irq + 1, wil6210_irq_rx, IRQF_SHARED,
464 			 WIL_NAME"_rx", wil);
465 	if (rc)
466 		goto free0;
467 
468 	rc = request_threaded_irq(irq + 2, wil6210_irq_misc,
469 				  wil6210_irq_misc_thread,
470 				  IRQF_SHARED, WIL_NAME"_misc", wil);
471 	if (rc)
472 		goto free1;
473 
474 	return 0;
475 	/* error branch */
476 free1:
477 	free_irq(irq + 1, wil);
478 free0:
479 	free_irq(irq, wil);
480 
481 	return rc;
482 }
483 
484 int wil6210_init_irq(struct wil6210_priv *wil, int irq)
485 {
486 	int rc;
487 	if (wil->n_msi == 3)
488 		rc = wil6210_request_3msi(wil, irq);
489 	else
490 		rc = request_threaded_irq(irq, wil6210_hardirq,
491 					  wil6210_thread_irq,
492 					  wil->n_msi ? 0 : IRQF_SHARED,
493 					  WIL_NAME, wil);
494 	if (rc)
495 		return rc;
496 
497 	wil6210_enable_irq(wil);
498 
499 	return 0;
500 }
501 
502 void wil6210_fini_irq(struct wil6210_priv *wil, int irq)
503 {
504 	wil6210_disable_irq(wil);
505 	free_irq(irq, wil);
506 	if (wil->n_msi == 3) {
507 		free_irq(irq + 1, wil);
508 		free_irq(irq + 2, wil);
509 	}
510 }
511