xref: /netbsd-src/sys/arch/arm/imx/imx23_icoll.c (revision 181254a7b1bdde6873432bffef2d2decc4b5c22f)
1 /* $Id: imx23_icoll.c,v 1.3 2014/02/25 08:39:39 martin Exp $ */
2 
3 /*
4  * Copyright (c) 2012 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Petri Laakso.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 #include <sys/param.h>
33 #include <sys/bus.h>
34 #include <sys/cpu.h>
35 #include <sys/device.h>
36 #include <sys/errno.h>
37 #include <sys/systm.h>
38 
39 #include <arm/cpufunc.h>
40 
41 #define _INTR_PRIVATE
42 #include <arm/pic/picvar.h>
43 
44 #include <arm/imx/imx23_icollreg.h>
45 #include <arm/imx/imx23var.h>
46 
47 #define ICOLL_SOFT_RST_LOOP 455		/* At least 1 us ... */
48 #define ICOLL_READ(sc, reg)						\
49 	bus_space_read_4(sc->sc_iot, sc->sc_hdl, (reg))
50 #define ICOLL_WRITE(sc, reg, val)					\
51 	bus_space_write_4(sc->sc_iot, sc->sc_hdl, (reg), (val))
52 
53 #define ICOLL_IRQ_REG_SIZE 0x10
54 #define ICOLL_CLR_IRQ(sc, irq)						\
55 	ICOLL_WRITE(sc, HW_ICOLL_INTERRUPT0_CLR +			\
56 			(irq) * ICOLL_IRQ_REG_SIZE,			\
57 			HW_ICOLL_INTERRUPT_ENABLE)
58 #define ICOLL_SET_IRQ(sc, irq)						\
59 	ICOLL_WRITE(sc, HW_ICOLL_INTERRUPT0_SET +			\
60 			(irq) * ICOLL_IRQ_REG_SIZE,			\
61 			HW_ICOLL_INTERRUPT_ENABLE)
62 #define ICOLL_GET_PRIO(sc, irq)						\
63 	__SHIFTOUT(ICOLL_READ(sc, HW_ICOLL_INTERRUPT0 +			\
64 			(irq) * ICOLL_IRQ_REG_SIZE),			\
65 			HW_ICOLL_INTERRUPT_PRIORITY)
66 
67 #define PICTOSOFTC(pic)							\
68 	((struct icoll_softc *)((char *)(pic) -				\
69 		offsetof(struct icoll_softc, sc_pic)))
70 
71 /*
72  * pic callbacks.
73  */
74 static void	icoll_unblock_irqs(struct pic_softc *, size_t, uint32_t);
75 static void	icoll_block_irqs(struct pic_softc *, size_t, uint32_t);
76 static int	icoll_find_pending_irqs(struct pic_softc *);
77 static void	icoll_establish_irq(struct pic_softc *, struct intrsource *);
78 static void	icoll_source_name(struct pic_softc *, int, char *, size_t);
79 static void	icoll_set_priority(struct pic_softc *, int);
80 
81 /*
82  * autoconf(9) callbacks.
83  */
84 static int	icoll_match(device_t, cfdata_t, void *);
85 static void	icoll_attach(device_t, device_t, void *);
86 static int	icoll_activate(device_t, enum devact);
87 
88 /*
89  * ARM interrupt handler.
90  */
91 void imx23_intr_dispatch(struct clockframe *);
92 
93 const static struct pic_ops icoll_pic_ops = {
94 	.pic_unblock_irqs = icoll_unblock_irqs,
95 	.pic_block_irqs = icoll_block_irqs,
96 	.pic_find_pending_irqs = icoll_find_pending_irqs,
97 	.pic_establish_irq = icoll_establish_irq,
98 	.pic_source_name = icoll_source_name,
99 	.pic_set_priority = icoll_set_priority
100 };
101 
102 struct icoll_softc {
103 	device_t sc_dev;
104 	struct pic_softc sc_pic;
105 	bus_space_tag_t sc_iot;
106 	bus_space_handle_t sc_hdl;
107 };
108 
109 /* For IRQ handler. */
110 static struct icoll_softc *icoll_sc;
111 
112 /*
113  * Private to driver.
114  */
115 static void	icoll_reset(struct icoll_softc *);
116 
117 CFATTACH_DECL3_NEW(icoll,
118 	sizeof(struct icoll_softc),
119 	icoll_match,
120 	icoll_attach,
121 	NULL,
122 	icoll_activate,
123 	NULL,
124 	NULL,
125 	0);
126 
127 /*
128  * ARM interrupt handler.
129  */
130 void
131 imx23_intr_dispatch(struct clockframe *frame)
132 {
133 	struct cpu_info * const ci = curcpu();
134 	struct pic_softc *pic_sc;
135 	int saved_spl;
136 	uint8_t irq;
137 	uint8_t prio;
138 
139 	pic_sc = &icoll_sc->sc_pic;
140 
141 	ci->ci_data.cpu_nintr++;
142 
143 	/* Save current spl. */
144 	saved_spl = curcpl();
145 
146 	/* IRQ to be handled. */
147 	irq = __SHIFTOUT(ICOLL_READ(icoll_sc, HW_ICOLL_STAT),
148 	    HW_ICOLL_STAT_VECTOR_NUMBER);
149 
150 	/* Save IRQ's priority. Acknowledge it later. */
151 	prio = ICOLL_GET_PRIO(icoll_sc, irq);
152 
153 	/*
154 	 * Notify ICOLL to deassert IRQ before re-enabling the IRQ's.
155 	 * This is done by writing anything to HW_ICOLL_VECTOR.
156 	 */
157 	ICOLL_WRITE(icoll_sc, HW_ICOLL_VECTOR,
158 	    __SHIFTIN(0x3fffffff, HW_ICOLL_VECTOR_IRQVECTOR));
159 
160 	/* Bogus IRQ. */
161 	if (irq == 0x7f) {
162 		cpsie(I32_bit);
163 		ICOLL_WRITE(icoll_sc, HW_ICOLL_LEVELACK, (1<<prio));
164 		cpsid(I32_bit);
165 		return;
166 	}
167 
168 	/* Raise the spl to the level of the IRQ. */
169 	if (pic_sc->pic_sources[irq]->is_ipl > ci->ci_cpl)
170 		saved_spl = _splraise(pic_sc->pic_sources[irq]->is_ipl);
171 
172 	/* Call the handler registered for the IRQ. */
173 	cpsie(I32_bit);
174 	pic_dispatch(pic_sc->pic_sources[irq], frame);
175 
176 	/*
177 	 * Acknowledge the IRQ by writing its priority to HW_ICOLL_LEVELACK.
178 	 * Interrupts should be enabled.
179 	 */
180 	ICOLL_WRITE(icoll_sc, HW_ICOLL_LEVELACK, (1<<prio));
181 	cpsid(I32_bit);
182 
183 	/* Restore the saved spl. */
184 	splx(saved_spl);
185 
186 	return;
187 }
188 
189 /*
190  * pic callbacks.
191  */
192 static void
193 icoll_unblock_irqs(struct pic_softc *pic, size_t irq_base, uint32_t irq_mask)
194 {
195 	struct icoll_softc *sc = PICTOSOFTC(pic);
196 	uint8_t b;
197 
198 	for (;;) {
199 		b = ffs(irq_mask);
200 		if (b == 0) break;
201 		b--;	/* Zero based index. */
202 		ICOLL_SET_IRQ(sc, irq_base + b);
203 		irq_mask &= ~(1<<b);
204 	}
205 
206 	return;
207 }
208 
209 static void
210 icoll_block_irqs(struct pic_softc *pic, size_t irq_base, uint32_t irq_mask)
211 {
212 	struct icoll_softc *sc = PICTOSOFTC(pic);
213 	uint8_t b;
214 
215 	for (;;) {
216 		b = ffs(irq_mask);
217 		if (b == 0) break;
218 		b--;	/* Zero based index. */
219 		ICOLL_CLR_IRQ(sc, irq_base + b);
220 		irq_mask &= ~(1<<b);
221 	}
222 
223 	return;
224 }
225 
226 static int
227 icoll_find_pending_irqs(struct pic_softc *pic)
228 {
229 	return 0; /* ICOLL HW doesn't provide list of pending interrupts. */
230 }
231 
232 static void
233 icoll_establish_irq(struct pic_softc *pic, struct intrsource *is)
234 {
235 	return; /* Nothing to establish. */
236 }
237 
238 static void
239 icoll_source_name(struct pic_softc *pic, int irq, char *is_source, size_t size)
240 {
241 	snprintf(is_source, size, "irq %d", irq);
242 }
243 
244 /*
245  * Set new interrupt priority level by enabling or disabling IRQ's.
246  */
247 static void
248 icoll_set_priority(struct pic_softc *pic, int newipl)
249 {
250 	struct icoll_softc *sc = PICTOSOFTC(pic);
251 	struct intrsource *is;
252 	int i;
253 
254 	for (i = 0; i < pic->pic_maxsources; i++) {
255 		is = pic->pic_sources[i];
256 		if (is == NULL)
257 			continue;
258 		if (is->is_ipl > newipl)
259 			ICOLL_SET_IRQ(sc, pic->pic_irqbase + is->is_irq);
260 		else
261 			ICOLL_CLR_IRQ(sc, pic->pic_irqbase + is->is_irq);
262 	}
263 }
264 
265 /*
266  * autoconf(9) callbacks.
267  */
268 static int
269 icoll_match(device_t parent, cfdata_t match, void *aux)
270 {
271 	struct apb_attach_args *aa = aux;
272 
273 	if ((aa->aa_addr == HW_ICOLL_BASE) && (aa->aa_size == HW_ICOLL_SIZE))
274 		return 1;
275 
276 	return 0;
277 }
278 
279 static void
280 icoll_attach(device_t parent, device_t self, void *aux)
281 {
282 	static int icoll_attached = 0;
283 	struct icoll_softc *sc = device_private(self);
284 	struct apb_attach_args *aa = aux;
285 
286 	if (icoll_attached)
287 		return;
288 
289 	icoll_sc = sc;
290 
291 	sc->sc_dev = self;
292 	sc->sc_iot = aa->aa_iot;
293 
294 	sc->sc_pic.pic_maxsources = IRQ_LAST + 1;
295 	sc->sc_pic.pic_ops = &icoll_pic_ops;
296 	strlcpy(sc->sc_pic.pic_name, device_xname(self),
297 	    sizeof(sc->sc_pic.pic_name));
298 
299 	if (bus_space_map(sc->sc_iot,
300 	    aa->aa_addr, aa->aa_size, 0, &(sc->sc_hdl))) {
301 		aprint_error_dev(sc->sc_dev, "unable to map bus space\n");
302 		return;
303 	}
304 
305 	icoll_reset(sc);
306 	pic_add(&sc->sc_pic, 0);
307 	aprint_normal("\n");
308 	icoll_attached = 1;
309 
310 	return;
311 }
312 
313 static int
314 icoll_activate(device_t self, enum devact act)
315 {
316 	return EOPNOTSUPP;
317 }
318 
319 /*
320  * Reset the ICOLL block.
321  *
322  * Inspired by i.MX23 RM "39.3.10 Correct Way to Soft Reset a Block"
323  */
324 static void
325 icoll_reset(struct icoll_softc *sc)
326 {
327 	unsigned int loop;
328 
329 	/*
330 	 * Prepare for soft-reset by making sure that SFTRST is not currently
331 	 * asserted. Also clear CLKGATE so we can wait for its assertion below.
332 	 */
333 	ICOLL_WRITE(sc, HW_ICOLL_CTRL_CLR, HW_ICOLL_CTRL_SFTRST);
334 
335 	/* Wait at least a microsecond for SFTRST to deassert. */
336 	loop = 0;
337 	while ((ICOLL_READ(sc, HW_ICOLL_CTRL) & HW_ICOLL_CTRL_SFTRST) ||
338 	    (loop < ICOLL_SOFT_RST_LOOP)) {
339 		loop++;
340 	}
341 
342 	/* Clear CLKGATE so we can wait for its assertion below. */
343 	ICOLL_WRITE(sc, HW_ICOLL_CTRL_CLR, HW_ICOLL_CTRL_CLKGATE);
344 
345 	/* Soft-reset the block. */
346 	ICOLL_WRITE(sc, HW_ICOLL_CTRL_SET, HW_ICOLL_CTRL_SFTRST);
347 
348 	/* Wait until clock is in the gated state. */
349 	while (!(ICOLL_READ(sc, HW_ICOLL_CTRL) & HW_ICOLL_CTRL_CLKGATE));
350 
351 	/* Bring block out of reset. */
352 	ICOLL_WRITE(sc, HW_ICOLL_CTRL_CLR, HW_ICOLL_CTRL_SFTRST);
353 
354 	loop = 0;
355 	while ((ICOLL_READ(sc, HW_ICOLL_CTRL) & HW_ICOLL_CTRL_SFTRST) ||
356 	    (loop < ICOLL_SOFT_RST_LOOP)) {
357 		loop++;
358 	}
359 
360 	ICOLL_WRITE(sc, HW_ICOLL_CTRL_CLR, HW_ICOLL_CTRL_CLKGATE);
361 
362 	/* Wait until clock is in the NON-gated state. */
363 	while (ICOLL_READ(sc, HW_ICOLL_CTRL) & HW_ICOLL_CTRL_CLKGATE);
364 
365 	return;
366 }
367