xref: /netbsd-src/sys/arch/arm/imx/imx23_icoll.c (revision 6a493d6bc668897c91594964a732d38505b70cbb)
1 /* $Id: imx23_icoll.c,v 1.2 2012/12/16 19:40:00 jkunz 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 #define _INTR_PRIVATE
40 #include <arm/pic/picvar.h>
41 
42 #include <arm/imx/imx23_icollreg.h>
43 #include <arm/imx/imx23var.h>
44 
45 #define ICOLL_SOFT_RST_LOOP 455		/* At least 1 us ... */
46 #define ICOLL_READ(sc, reg)						\
47 	bus_space_read_4(sc->sc_iot, sc->sc_hdl, (reg))
48 #define ICOLL_WRITE(sc, reg, val)					\
49 	bus_space_write_4(sc->sc_iot, sc->sc_hdl, (reg), (val))
50 
51 #define ICOLL_IRQ_REG_SIZE 0x10
52 #define ICOLL_CLR_IRQ(sc, irq)						\
53 	ICOLL_WRITE(sc, HW_ICOLL_INTERRUPT0_CLR +			\
54 			(irq) * ICOLL_IRQ_REG_SIZE,			\
55 			HW_ICOLL_INTERRUPT_ENABLE)
56 #define ICOLL_SET_IRQ(sc, irq)						\
57 	ICOLL_WRITE(sc, HW_ICOLL_INTERRUPT0_SET +			\
58 			(irq) * ICOLL_IRQ_REG_SIZE,			\
59 			HW_ICOLL_INTERRUPT_ENABLE)
60 #define ICOLL_GET_PRIO(sc, irq)						\
61 	__SHIFTOUT(ICOLL_READ(sc, HW_ICOLL_INTERRUPT0 +			\
62 			(irq) * ICOLL_IRQ_REG_SIZE),			\
63 			HW_ICOLL_INTERRUPT_PRIORITY)
64 
65 #define PICTOSOFTC(pic)							\
66 	((struct icoll_softc *)((char *)(pic) -				\
67 		offsetof(struct icoll_softc, sc_pic)))
68 
69 /*
70  * pic callbacks.
71  */
72 static void	icoll_unblock_irqs(struct pic_softc *, size_t, uint32_t);
73 static void	icoll_block_irqs(struct pic_softc *, size_t, uint32_t);
74 static int	icoll_find_pending_irqs(struct pic_softc *);
75 static void	icoll_establish_irq(struct pic_softc *, struct intrsource *);
76 static void	icoll_source_name(struct pic_softc *, int, char *, size_t);
77 static void	icoll_set_priority(struct pic_softc *, int);
78 
79 /*
80  * autoconf(9) callbacks.
81  */
82 static int	icoll_match(device_t, cfdata_t, void *);
83 static void	icoll_attach(device_t, device_t, void *);
84 static int	icoll_activate(device_t, enum devact);
85 
86 /*
87  * ARM interrupt handler.
88  */
89 void imx23_intr_dispatch(struct clockframe *);
90 
91 const static struct pic_ops icoll_pic_ops = {
92 	.pic_unblock_irqs = icoll_unblock_irqs,
93 	.pic_block_irqs = icoll_block_irqs,
94 	.pic_find_pending_irqs = icoll_find_pending_irqs,
95 	.pic_establish_irq = icoll_establish_irq,
96 	.pic_source_name = icoll_source_name,
97 	.pic_set_priority = icoll_set_priority
98 };
99 
100 struct icoll_softc {
101 	device_t sc_dev;
102 	struct pic_softc sc_pic;
103 	bus_space_tag_t sc_iot;
104 	bus_space_handle_t sc_hdl;
105 };
106 
107 /* For IRQ handler. */
108 static struct icoll_softc *icoll_sc;
109 
110 /*
111  * Private to driver.
112  */
113 static void	icoll_reset(struct icoll_softc *);
114 
115 CFATTACH_DECL3_NEW(icoll,
116 	sizeof(struct icoll_softc),
117 	icoll_match,
118 	icoll_attach,
119 	NULL,
120 	icoll_activate,
121 	NULL,
122 	NULL,
123 	0);
124 
125 /*
126  * ARM interrupt handler.
127  */
128 void
129 imx23_intr_dispatch(struct clockframe *frame)
130 {
131 	struct cpu_info * const ci = curcpu();
132 	struct pic_softc *pic_sc;
133 	int saved_spl;
134 	uint8_t irq;
135 	uint8_t prio;
136 
137 	pic_sc = &icoll_sc->sc_pic;
138 
139 	ci->ci_data.cpu_nintr++;
140 
141 	/* Save current spl. */
142 	saved_spl = curcpl();
143 
144 	/* IRQ to be handled. */
145 	irq = __SHIFTOUT(ICOLL_READ(icoll_sc, HW_ICOLL_STAT),
146 	    HW_ICOLL_STAT_VECTOR_NUMBER);
147 
148 	/* Save IRQ's priority. Acknowledge it later. */
149 	prio = ICOLL_GET_PRIO(icoll_sc, irq);
150 
151 	/*
152 	 * Notify ICOLL to deassert IRQ before re-enabling the IRQ's.
153 	 * This is done by writing anything to HW_ICOLL_VECTOR.
154 	 */
155 	ICOLL_WRITE(icoll_sc, HW_ICOLL_VECTOR,
156 	    __SHIFTIN(0x3fffffff, HW_ICOLL_VECTOR_IRQVECTOR));
157 
158 	/* Bogus IRQ. */
159 	if (irq == 0x7f) {
160 		cpsie(I32_bit);
161 		ICOLL_WRITE(icoll_sc, HW_ICOLL_LEVELACK, (1<<prio));
162 		cpsid(I32_bit);
163 		return;
164 	}
165 
166 	/* Raise the spl to the level of the IRQ. */
167 	if (pic_sc->pic_sources[irq]->is_ipl > ci->ci_cpl)
168 		saved_spl = _splraise(pic_sc->pic_sources[irq]->is_ipl);
169 
170 	/* Call the handler registered for the IRQ. */
171 	cpsie(I32_bit);
172 	pic_dispatch(pic_sc->pic_sources[irq], frame);
173 
174 	/*
175 	 * Acknowledge the IRQ by writing its priority to HW_ICOLL_LEVELACK.
176 	 * Interrupts should be enabled.
177 	 */
178 	ICOLL_WRITE(icoll_sc, HW_ICOLL_LEVELACK, (1<<prio));
179 	cpsid(I32_bit);
180 
181 	/* Restore the saved spl. */
182 	splx(saved_spl);
183 
184 	return;
185 }
186 
187 /*
188  * pic callbacks.
189  */
190 static void
191 icoll_unblock_irqs(struct pic_softc *pic, size_t irq_base, uint32_t irq_mask)
192 {
193 	struct icoll_softc *sc = PICTOSOFTC(pic);
194 	uint8_t b;
195 
196 	for (;;) {
197 		b = ffs(irq_mask);
198 		if (b == 0) break;
199 		b--;	/* Zero based index. */
200 		ICOLL_SET_IRQ(sc, irq_base + b);
201 		irq_mask &= ~(1<<b);
202 	}
203 
204 	return;
205 }
206 
207 static void
208 icoll_block_irqs(struct pic_softc *pic, size_t irq_base, uint32_t irq_mask)
209 {
210 	struct icoll_softc *sc = PICTOSOFTC(pic);
211 	uint8_t b;
212 
213 	for (;;) {
214 		b = ffs(irq_mask);
215 		if (b == 0) break;
216 		b--;	/* Zero based index. */
217 		ICOLL_CLR_IRQ(sc, irq_base + b);
218 		irq_mask &= ~(1<<b);
219 	}
220 
221 	return;
222 }
223 
224 static int
225 icoll_find_pending_irqs(struct pic_softc *pic)
226 {
227 	return 0; /* ICOLL HW doesn't provide list of pending interrupts. */
228 }
229 
230 static void
231 icoll_establish_irq(struct pic_softc *pic, struct intrsource *is)
232 {
233 	return; /* Nothing to establish. */
234 }
235 
236 static void
237 icoll_source_name(struct pic_softc *pic, int irq, char *is_source, size_t size)
238 {
239 	snprintf(is_source, size, "irq %d", irq);
240 }
241 
242 /*
243  * Set new interrupt priority level by enabling or disabling IRQ's.
244  */
245 static void
246 icoll_set_priority(struct pic_softc *pic, int newipl)
247 {
248 	struct icoll_softc *sc = PICTOSOFTC(pic);
249 	struct intrsource *is;
250 	int i;
251 
252 	for (i = 0; i < pic->pic_maxsources; i++) {
253 		is = pic->pic_sources[i];
254 		if (is == NULL)
255 			continue;
256 		if (is->is_ipl > newipl)
257 			ICOLL_SET_IRQ(sc, pic->pic_irqbase + is->is_irq);
258 		else
259 			ICOLL_CLR_IRQ(sc, pic->pic_irqbase + is->is_irq);
260 	}
261 }
262 
263 /*
264  * autoconf(9) callbacks.
265  */
266 static int
267 icoll_match(device_t parent, cfdata_t match, void *aux)
268 {
269 	struct apb_attach_args *aa = aux;
270 
271 	if ((aa->aa_addr == HW_ICOLL_BASE) && (aa->aa_size == HW_ICOLL_SIZE))
272 		return 1;
273 
274 	return 0;
275 }
276 
277 static void
278 icoll_attach(device_t parent, device_t self, void *aux)
279 {
280 	static int icoll_attached = 0;
281 	struct icoll_softc *sc = device_private(self);
282 	struct apb_attach_args *aa = aux;
283 
284 	if (icoll_attached)
285 		return;
286 
287 	icoll_sc = sc;
288 
289 	sc->sc_dev = self;
290 	sc->sc_iot = aa->aa_iot;
291 
292 	sc->sc_pic.pic_maxsources = IRQ_LAST + 1;
293 	sc->sc_pic.pic_ops = &icoll_pic_ops;
294 	strlcpy(sc->sc_pic.pic_name, device_xname(self),
295 	    sizeof(sc->sc_pic.pic_name));
296 
297 	if (bus_space_map(sc->sc_iot,
298 	    aa->aa_addr, aa->aa_size, 0, &(sc->sc_hdl))) {
299 		aprint_error_dev(sc->sc_dev, "unable to map bus space\n");
300 		return;
301 	}
302 
303 	icoll_reset(sc);
304 	pic_add(&sc->sc_pic, 0);
305 	aprint_normal("\n");
306 	icoll_attached = 1;
307 
308 	return;
309 }
310 
311 static int
312 icoll_activate(device_t self, enum devact act)
313 {
314 	return EOPNOTSUPP;
315 }
316 
317 /*
318  * Reset the ICOLL block.
319  *
320  * Inspired by i.MX23 RM "39.3.10 Correct Way to Soft Reset a Block"
321  */
322 static void
323 icoll_reset(struct icoll_softc *sc)
324 {
325 	unsigned int loop;
326 
327 	/*
328 	 * Prepare for soft-reset by making sure that SFTRST is not currently
329 	 * asserted. Also clear CLKGATE so we can wait for its assertion below.
330 	 */
331 	ICOLL_WRITE(sc, HW_ICOLL_CTRL_CLR, HW_ICOLL_CTRL_SFTRST);
332 
333 	/* Wait at least a microsecond for SFTRST to deassert. */
334 	loop = 0;
335 	while ((ICOLL_READ(sc, HW_ICOLL_CTRL) & HW_ICOLL_CTRL_SFTRST) ||
336 	    (loop < ICOLL_SOFT_RST_LOOP)) {
337 		loop++;
338 	}
339 
340 	/* Clear CLKGATE so we can wait for its assertion below. */
341 	ICOLL_WRITE(sc, HW_ICOLL_CTRL_CLR, HW_ICOLL_CTRL_CLKGATE);
342 
343 	/* Soft-reset the block. */
344 	ICOLL_WRITE(sc, HW_ICOLL_CTRL_SET, HW_ICOLL_CTRL_SFTRST);
345 
346 	/* Wait until clock is in the gated state. */
347 	while (!(ICOLL_READ(sc, HW_ICOLL_CTRL) & HW_ICOLL_CTRL_CLKGATE));
348 
349 	/* Bring block out of reset. */
350 	ICOLL_WRITE(sc, HW_ICOLL_CTRL_CLR, HW_ICOLL_CTRL_SFTRST);
351 
352 	loop = 0;
353 	while ((ICOLL_READ(sc, HW_ICOLL_CTRL) & HW_ICOLL_CTRL_SFTRST) ||
354 	    (loop < ICOLL_SOFT_RST_LOOP)) {
355 		loop++;
356 	}
357 
358 	ICOLL_WRITE(sc, HW_ICOLL_CTRL_CLR, HW_ICOLL_CTRL_CLKGATE);
359 
360 	/* Wait until clock is in the NON-gated state. */
361 	while (ICOLL_READ(sc, HW_ICOLL_CTRL) & HW_ICOLL_CTRL_CLKGATE);
362 
363 	return;
364 }
365