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 
21 /**
22  * Theory of operation:
23  *
24  * There is ISR pseudo-cause register,
25  * dma_rgf->DMA_RGF.PSEUDO_CAUSE.PSEUDO_CAUSE
26  * Its bits represents OR'ed bits from 3 real ISR registers:
27  * TX, RX, and MISC.
28  *
29  * Registers may be configured to either "write 1 to clear" or
30  * "clear on read" mode
31  *
32  * When handling interrupt, one have to mask/unmask interrupts for the
33  * real ISR registers, or hardware may malfunction.
34  *
35  */
36 
37 #define WIL6210_IRQ_DISABLE	(0xFFFFFFFFUL)
38 #define WIL6210_IMC_RX		BIT_DMA_EP_RX_ICR_RX_DONE
39 #define WIL6210_IMC_TX		(BIT_DMA_EP_TX_ICR_TX_DONE | \
40 				BIT_DMA_EP_TX_ICR_TX_DONE_N(0))
41 #define WIL6210_IMC_MISC	(ISR_MISC_FW_READY | \
42 				 ISR_MISC_MBOX_EVT | \
43 				 ISR_MISC_FW_ERROR)
44 
45 #define WIL6210_IRQ_PSEUDO_MASK (u32)(~(BIT_DMA_PSEUDO_CAUSE_RX | \
46 					BIT_DMA_PSEUDO_CAUSE_TX | \
47 					BIT_DMA_PSEUDO_CAUSE_MISC))
48 
49 #if defined(CONFIG_WIL6210_ISR_COR)
50 /* configure to Clear-On-Read mode */
51 #define WIL_ICR_ICC_VALUE	(0xFFFFFFFFUL)
52 
53 static inline void wil_icr_clear(u32 x, void __iomem *addr)
54 {
55 }
56 #else /* defined(CONFIG_WIL6210_ISR_COR) */
57 /* configure to Write-1-to-Clear mode */
58 #define WIL_ICR_ICC_VALUE	(0UL)
59 
60 static inline void wil_icr_clear(u32 x, void __iomem *addr)
61 {
62 	iowrite32(x, addr);
63 }
64 #endif /* defined(CONFIG_WIL6210_ISR_COR) */
65 
66 static inline u32 wil_ioread32_and_clear(void __iomem *addr)
67 {
68 	u32 x = ioread32(addr);
69 
70 	wil_icr_clear(x, addr);
71 
72 	return x;
73 }
74 
75 static void wil6210_mask_irq_tx(struct wil6210_priv *wil)
76 {
77 	iowrite32(WIL6210_IRQ_DISABLE, wil->csr +
78 		  HOSTADDR(RGF_DMA_EP_TX_ICR) +
79 		  offsetof(struct RGF_ICR, IMS));
80 }
81 
82 static void wil6210_mask_irq_rx(struct wil6210_priv *wil)
83 {
84 	iowrite32(WIL6210_IRQ_DISABLE, wil->csr +
85 		  HOSTADDR(RGF_DMA_EP_RX_ICR) +
86 		  offsetof(struct RGF_ICR, IMS));
87 }
88 
89 static void wil6210_mask_irq_misc(struct wil6210_priv *wil)
90 {
91 	iowrite32(WIL6210_IRQ_DISABLE, wil->csr +
92 		  HOSTADDR(RGF_DMA_EP_MISC_ICR) +
93 		  offsetof(struct RGF_ICR, IMS));
94 }
95 
96 static void wil6210_mask_irq_pseudo(struct wil6210_priv *wil)
97 {
98 	wil_dbg_irq(wil, "%s()\n", __func__);
99 
100 	iowrite32(WIL6210_IRQ_DISABLE, wil->csr +
101 		  HOSTADDR(RGF_DMA_PSEUDO_CAUSE_MASK_SW));
102 
103 	clear_bit(wil_status_irqen, &wil->status);
104 }
105 
106 static void wil6210_unmask_irq_tx(struct wil6210_priv *wil)
107 {
108 	iowrite32(WIL6210_IMC_TX, wil->csr +
109 		  HOSTADDR(RGF_DMA_EP_TX_ICR) +
110 		  offsetof(struct RGF_ICR, IMC));
111 }
112 
113 static void wil6210_unmask_irq_rx(struct wil6210_priv *wil)
114 {
115 	iowrite32(WIL6210_IMC_RX, wil->csr +
116 		  HOSTADDR(RGF_DMA_EP_RX_ICR) +
117 		  offsetof(struct RGF_ICR, IMC));
118 }
119 
120 static void wil6210_unmask_irq_misc(struct wil6210_priv *wil)
121 {
122 	iowrite32(WIL6210_IMC_MISC, wil->csr +
123 		  HOSTADDR(RGF_DMA_EP_MISC_ICR) +
124 		  offsetof(struct RGF_ICR, IMC));
125 }
126 
127 static void wil6210_unmask_irq_pseudo(struct wil6210_priv *wil)
128 {
129 	wil_dbg_irq(wil, "%s()\n", __func__);
130 
131 	set_bit(wil_status_irqen, &wil->status);
132 
133 	iowrite32(WIL6210_IRQ_PSEUDO_MASK, wil->csr +
134 		  HOSTADDR(RGF_DMA_PSEUDO_CAUSE_MASK_SW));
135 }
136 
137 void wil6210_disable_irq(struct wil6210_priv *wil)
138 {
139 	wil_dbg_irq(wil, "%s()\n", __func__);
140 
141 	wil6210_mask_irq_tx(wil);
142 	wil6210_mask_irq_rx(wil);
143 	wil6210_mask_irq_misc(wil);
144 	wil6210_mask_irq_pseudo(wil);
145 }
146 
147 void wil6210_enable_irq(struct wil6210_priv *wil)
148 {
149 	wil_dbg_irq(wil, "%s()\n", __func__);
150 
151 	iowrite32(WIL_ICR_ICC_VALUE, wil->csr + HOSTADDR(RGF_DMA_EP_RX_ICR) +
152 		  offsetof(struct RGF_ICR, ICC));
153 	iowrite32(WIL_ICR_ICC_VALUE, wil->csr + HOSTADDR(RGF_DMA_EP_TX_ICR) +
154 		  offsetof(struct RGF_ICR, ICC));
155 	iowrite32(WIL_ICR_ICC_VALUE, wil->csr + HOSTADDR(RGF_DMA_EP_MISC_ICR) +
156 		  offsetof(struct RGF_ICR, ICC));
157 
158 	wil6210_unmask_irq_pseudo(wil);
159 	wil6210_unmask_irq_tx(wil);
160 	wil6210_unmask_irq_rx(wil);
161 	wil6210_unmask_irq_misc(wil);
162 }
163 
164 static irqreturn_t wil6210_irq_rx(int irq, void *cookie)
165 {
166 	struct wil6210_priv *wil = cookie;
167 	u32 isr = wil_ioread32_and_clear(wil->csr +
168 					 HOSTADDR(RGF_DMA_EP_RX_ICR) +
169 					 offsetof(struct RGF_ICR, ICR));
170 
171 	wil_dbg_irq(wil, "ISR RX 0x%08x\n", isr);
172 
173 	if (!isr) {
174 		wil_err(wil, "spurious IRQ: RX\n");
175 		return IRQ_NONE;
176 	}
177 
178 	wil6210_mask_irq_rx(wil);
179 
180 	if (isr & BIT_DMA_EP_RX_ICR_RX_DONE) {
181 		wil_dbg_irq(wil, "RX done\n");
182 		isr &= ~BIT_DMA_EP_RX_ICR_RX_DONE;
183 		wil_rx_handle(wil);
184 	}
185 
186 	if (isr)
187 		wil_err(wil, "un-handled RX ISR bits 0x%08x\n", isr);
188 
189 	wil6210_unmask_irq_rx(wil);
190 
191 	return IRQ_HANDLED;
192 }
193 
194 static irqreturn_t wil6210_irq_tx(int irq, void *cookie)
195 {
196 	struct wil6210_priv *wil = cookie;
197 	u32 isr = wil_ioread32_and_clear(wil->csr +
198 					 HOSTADDR(RGF_DMA_EP_TX_ICR) +
199 					 offsetof(struct RGF_ICR, ICR));
200 
201 	wil_dbg_irq(wil, "ISR TX 0x%08x\n", isr);
202 
203 	if (!isr) {
204 		wil_err(wil, "spurious IRQ: TX\n");
205 		return IRQ_NONE;
206 	}
207 
208 	wil6210_mask_irq_tx(wil);
209 
210 	if (isr & BIT_DMA_EP_TX_ICR_TX_DONE) {
211 		uint i;
212 		wil_dbg_irq(wil, "TX done\n");
213 		isr &= ~BIT_DMA_EP_TX_ICR_TX_DONE;
214 		for (i = 0; i < 24; i++) {
215 			u32 mask = BIT_DMA_EP_TX_ICR_TX_DONE_N(i);
216 			if (isr & mask) {
217 				isr &= ~mask;
218 				wil_dbg_irq(wil, "TX done(%i)\n", i);
219 				wil_tx_complete(wil, i);
220 			}
221 		}
222 	}
223 
224 	if (isr)
225 		wil_err(wil, "un-handled TX ISR bits 0x%08x\n", isr);
226 
227 	wil6210_unmask_irq_tx(wil);
228 
229 	return IRQ_HANDLED;
230 }
231 
232 static void wil_notify_fw_error(struct wil6210_priv *wil)
233 {
234 	struct device *dev = &wil_to_ndev(wil)->dev;
235 	char *envp[3] = {
236 		[0] = "SOURCE=wil6210",
237 		[1] = "EVENT=FW_ERROR",
238 		[2] = NULL,
239 	};
240 	kobject_uevent_env(&dev->kobj, KOBJ_CHANGE, envp);
241 }
242 
243 static void wil_cache_mbox_regs(struct wil6210_priv *wil)
244 {
245 	/* make shadow copy of registers that should not change on run time */
246 	wil_memcpy_fromio_32(&wil->mbox_ctl, wil->csr + HOST_MBOX,
247 			     sizeof(struct wil6210_mbox_ctl));
248 	wil_mbox_ring_le2cpus(&wil->mbox_ctl.rx);
249 	wil_mbox_ring_le2cpus(&wil->mbox_ctl.tx);
250 }
251 
252 static irqreturn_t wil6210_irq_misc(int irq, void *cookie)
253 {
254 	struct wil6210_priv *wil = cookie;
255 	u32 isr = wil_ioread32_and_clear(wil->csr +
256 					 HOSTADDR(RGF_DMA_EP_MISC_ICR) +
257 					 offsetof(struct RGF_ICR, ICR));
258 
259 	wil_dbg_irq(wil, "ISR MISC 0x%08x\n", isr);
260 
261 	if (!isr) {
262 		wil_err(wil, "spurious IRQ: MISC\n");
263 		return IRQ_NONE;
264 	}
265 
266 	wil6210_mask_irq_misc(wil);
267 
268 	if (isr & ISR_MISC_FW_ERROR) {
269 		wil_err(wil, "Firmware error detected\n");
270 		clear_bit(wil_status_fwready, &wil->status);
271 		/*
272 		 * do not clear @isr here - we do 2-nd part in thread
273 		 * there, user space get notified, and it should be done
274 		 * in non-atomic context
275 		 */
276 	}
277 
278 	if (isr & ISR_MISC_FW_READY) {
279 		wil_dbg_irq(wil, "IRQ: FW ready\n");
280 		wil_cache_mbox_regs(wil);
281 		set_bit(wil_status_reset_done, &wil->status);
282 		/**
283 		 * Actual FW ready indicated by the
284 		 * WMI_FW_READY_EVENTID
285 		 */
286 		isr &= ~ISR_MISC_FW_READY;
287 	}
288 
289 	wil->isr_misc = isr;
290 
291 	if (isr) {
292 		return IRQ_WAKE_THREAD;
293 	} else {
294 		wil6210_unmask_irq_misc(wil);
295 		return IRQ_HANDLED;
296 	}
297 }
298 
299 static irqreturn_t wil6210_irq_misc_thread(int irq, void *cookie)
300 {
301 	struct wil6210_priv *wil = cookie;
302 	u32 isr = wil->isr_misc;
303 
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 	wil_dbg_irq(wil, "Pseudo IRQ 0x%08x\n", pseudo_cause);
412 
413 	wil6210_mask_irq_pseudo(wil);
414 
415 	/* Discover real IRQ cause
416 	 * There are 2 possible phases for every IRQ:
417 	 * - hard IRQ handler called right here
418 	 * - threaded handler called later
419 	 *
420 	 * Hard IRQ handler reads and clears ISR.
421 	 *
422 	 * If threaded handler requested, hard IRQ handler
423 	 * returns IRQ_WAKE_THREAD and saves ISR register value
424 	 * for the threaded handler use.
425 	 *
426 	 * voting for wake thread - need at least 1 vote
427 	 */
428 	if ((pseudo_cause & BIT_DMA_PSEUDO_CAUSE_RX) &&
429 	    (wil6210_irq_rx(irq, cookie) == IRQ_WAKE_THREAD))
430 		rc = IRQ_WAKE_THREAD;
431 
432 	if ((pseudo_cause & BIT_DMA_PSEUDO_CAUSE_TX) &&
433 	    (wil6210_irq_tx(irq, cookie) == IRQ_WAKE_THREAD))
434 		rc = IRQ_WAKE_THREAD;
435 
436 	if ((pseudo_cause & BIT_DMA_PSEUDO_CAUSE_MISC) &&
437 	    (wil6210_irq_misc(irq, cookie) == IRQ_WAKE_THREAD))
438 		rc = IRQ_WAKE_THREAD;
439 
440 	/* if thread is requested, it will unmask IRQ */
441 	if (rc != IRQ_WAKE_THREAD)
442 		wil6210_unmask_irq_pseudo(wil);
443 
444 	return rc;
445 }
446 
447 static int wil6210_request_3msi(struct wil6210_priv *wil, int irq)
448 {
449 	int rc;
450 	/*
451 	 * IRQ's are in the following order:
452 	 * - Tx
453 	 * - Rx
454 	 * - Misc
455 	 */
456 
457 	rc = request_irq(irq, wil6210_irq_tx, IRQF_SHARED,
458 			 WIL_NAME"_tx", wil);
459 	if (rc)
460 		return rc;
461 
462 	rc = request_irq(irq + 1, wil6210_irq_rx, IRQF_SHARED,
463 			 WIL_NAME"_rx", wil);
464 	if (rc)
465 		goto free0;
466 
467 	rc = request_threaded_irq(irq + 2, wil6210_irq_misc,
468 				  wil6210_irq_misc_thread,
469 				  IRQF_SHARED, WIL_NAME"_misc", wil);
470 	if (rc)
471 		goto free1;
472 
473 	return 0;
474 	/* error branch */
475 free1:
476 	free_irq(irq + 1, wil);
477 free0:
478 	free_irq(irq, wil);
479 
480 	return rc;
481 }
482 
483 int wil6210_init_irq(struct wil6210_priv *wil, int irq)
484 {
485 	int rc;
486 	if (wil->n_msi == 3)
487 		rc = wil6210_request_3msi(wil, irq);
488 	else
489 		rc = request_threaded_irq(irq, wil6210_hardirq,
490 					  wil6210_thread_irq,
491 					  wil->n_msi ? 0 : IRQF_SHARED,
492 					  WIL_NAME, wil);
493 	if (rc)
494 		return rc;
495 
496 	wil6210_enable_irq(wil);
497 
498 	return 0;
499 }
500 
501 void wil6210_fini_irq(struct wil6210_priv *wil, int irq)
502 {
503 	wil6210_disable_irq(wil);
504 	free_irq(irq, wil);
505 	if (wil->n_msi == 3) {
506 		free_irq(irq + 1, wil);
507 		free_irq(irq + 2, wil);
508 	}
509 }
510