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      1 /* $NetBSD: am18xx_intc.c,v 1.2 2026/07/30 15:08:08 yurix Exp $ */
      2 
      3 /*-
      4 * Copyright (c) 2025 The NetBSD Foundation, Inc.
      5 * All rights reserved.
      6 *
      7 * This code is derived from software contributed to The NetBSD Foundation
      8 * by Yuri Honegger.
      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 /*
     33  * Interrupt controller for the TI AM18XX SOC
     34  */
     35 
     36 #define _INTR_PRIVATE
     37 
     38 #include <sys/cdefs.h>
     39 #include <sys/cpu.h>
     40 #include <sys/device.h>
     41 
     42 #include <dev/fdt/fdtvar.h>
     43 
     44 #include <arm/armreg.h>
     45 #include <arm/pic/picvar.h>
     46 
     47 struct am18xx_intc_softc {
     48 	struct pic_softc sc_pic;
     49 	bus_space_tag_t sc_bst;
     50 	bus_space_handle_t sc_bsh;
     51 	int sc_num_irqs;
     52 };
     53 
     54 static int 	am18xx_intc_match(device_t, cfdata_t, void *);
     55 static void 	am18xx_intc_attach(device_t, device_t, void *);
     56 
     57 static void	am18xx_intc_unblock_irqs(struct pic_softc *, size_t, uint32_t);
     58 static void	am18xx_intc_block_irqs(struct pic_softc *, size_t, uint32_t);
     59 static void	am18xx_intc_establish_irq(struct pic_softc *,
     60 					  struct intrsource *);
     61 static void	am18xx_intc_set_priority(struct pic_softc *, int);
     62 static void	am18xx_intc_irq_handler(void *);
     63 static void	*am18xx_intc_fdt_establish(device_t, u_int *, int, int,
     64 					   int (*)(void *), void *,
     65 					   const char *);
     66 static void 	am18xx_intc_fdt_disestablish(device_t, void *);
     67 static bool 	am18xx_intc_fdt_intrstr(device_t, u_int *, char *, size_t);
     68 static void 	am18xx_intc_enable_interrupts(struct am18xx_intc_softc *);
     69 
     70 #define AM18XX_AINTC_CR 	0x4
     71 #define AM18XX_AINTC_GER 	0x10
     72 #define AM18XX_AINTC_SECR1	0x280
     73 #define AM18XX_AINTC_ESR1 	0x300
     74 #define AM18XX_AINTC_ECR1 	0x380
     75 #define AM18XX_AINTC_CMR0 	0x400
     76 #define AM18XX_AINTC_HIER 	0x1500
     77 
     78 #define AM18XX_AINTC_GER_ENABLE	1
     79 #define AM18XX_AINTC_HIER_IRQ	2
     80 #define AM18XX_AINTC_IRQ_CHANNEL	4 /* any number between 2 and 31 works */
     81 
     82 #define	INTC_READ(sc, reg)					\
     83 	bus_space_read_4((sc)->sc_bst, (sc)->sc_bsh, reg)
     84 #define	INTC_WRITE(sc, reg, val)				\
     85 	bus_space_write_4((sc)->sc_bst, (sc)->sc_bsh, reg, val)
     86 #define	PICTOSOFTC(pic)	\
     87 	((struct am18xx_intc_softc *) \
     88 	     ((uintptr_t)(pic) - offsetof(struct am18xx_intc_softc, sc_pic)))
     89 
     90 static struct am18xx_intc_softc *intc_softc;
     91 
     92 CFATTACH_DECL_NEW(am18xxintc, sizeof(struct am18xx_intc_softc),
     93 		  am18xx_intc_match, am18xx_intc_attach, NULL, NULL);
     94 
     95 static const struct device_compatible_entry compat_data[] = {
     96 	{ .compat = "ti,cp-intc" },
     97 	DEVICE_COMPAT_EOL
     98 };
     99 
    100 static const struct fdtbus_interrupt_controller_func am18xx_intc_fdt_funcs = {
    101 	.establish = am18xx_intc_fdt_establish,
    102 	.disestablish = am18xx_intc_fdt_disestablish,
    103 	.intrstr = am18xx_intc_fdt_intrstr,
    104 };
    105 
    106 static const struct pic_ops am18xx_intc_picops = {
    107 	.pic_unblock_irqs = am18xx_intc_unblock_irqs,
    108 	.pic_block_irqs = am18xx_intc_block_irqs,
    109 	.pic_establish_irq = am18xx_intc_establish_irq,
    110 	.pic_set_priority = am18xx_intc_set_priority,
    111 };
    112 
    113 static void *
    114 am18xx_intc_fdt_establish(device_t dev, u_int *specifier, int ipl, int flags,
    115 			  int (*func)(void *), void *arg, const char *xname)
    116 {
    117 	struct am18xx_intc_softc * const sc = device_private(dev);
    118 
    119 	const u_int irq = be32toh(specifier[0]);
    120 	if (irq >= sc->sc_num_irqs) {
    121 		device_printf(dev, "IRQ %u is out of range\n", irq);
    122 		return NULL;
    123 	}
    124 
    125 	const u_int mpsafe = (flags & FDT_INTR_MPSAFE) ? IST_MPSAFE : 0;
    126 	return intr_establish_xname(irq, ipl, IST_LEVEL | mpsafe, func, arg,
    127 				    xname);
    128 }
    129 
    130 static void
    131 am18xx_intc_fdt_disestablish(device_t dev, void *ih)
    132 {
    133 	return intr_disestablish(ih);
    134 }
    135 
    136 static bool
    137 am18xx_intc_fdt_intrstr(device_t dev, u_int *specifier, char *buf,
    138 		      size_t buflen)
    139 {
    140 	const u_int irq = be32toh(specifier[0]);
    141 	snprintf(buf, buflen, "irq %d", irq);
    142 	return true;
    143 }
    144 
    145 static void
    146 am18xx_intc_unblock_irqs(struct pic_softc *pic, size_t irq_base, uint32_t mask)
    147 {
    148 	struct am18xx_intc_softc * const sc = PICTOSOFTC(pic);
    149 
    150 	const size_t group = irq_base / 32;
    151 	uint32_t esr_reg = AM18XX_AINTC_ESR1 + 4 * group;
    152 	INTC_WRITE(sc, esr_reg, mask);
    153 }
    154 
    155 static void
    156 am18xx_intc_block_irqs(struct pic_softc *pic, size_t irq_base, uint32_t mask)
    157 {
    158 	struct am18xx_intc_softc * const sc = PICTOSOFTC(pic);
    159 
    160 	const size_t group = irq_base / 32;
    161 	uint32_t ecr_reg = AM18XX_AINTC_ECR1 + 4 * group;
    162 	INTC_WRITE(sc, ecr_reg, mask);
    163 }
    164 
    165 static void
    166 am18xx_intc_establish_irq(struct pic_softc *pic, struct intrsource *is)
    167 {
    168 	struct am18xx_intc_softc * const sc = PICTOSOFTC(pic);
    169 
    170 	/* there is one CMR register per 4 interrupts*/
    171 	uint32_t cmr_reg = AM18XX_AINTC_CMR0 + (is->is_irq & (~0x3));
    172 	uint32_t cmr_shift = (is->is_irq % 4) * 8;
    173 
    174 	/* update CMR register with channel */
    175 	uint32_t cmr = INTC_READ(sc, cmr_reg);
    176 	cmr = cmr & ~(0xFF<<cmr_shift);
    177 	cmr |= AM18XX_AINTC_IRQ_CHANNEL << cmr_shift;
    178 	INTC_WRITE(sc, cmr_reg, cmr);
    179 }
    180 
    181 static void
    182 am18xx_intc_set_priority(struct pic_softc *pic, int new_ipl)
    183 {
    184 	curcpu()->ci_cpl = new_ipl;
    185 }
    186 
    187 static int
    188 find_pending_irqs(struct am18xx_intc_softc *sc, size_t group)
    189 {
    190 	uint32_t reg = AM18XX_AINTC_SECR1 + (4 * group);
    191 	uint32_t pending = INTC_READ(sc, reg);
    192 
    193 	/* clear interrupts */
    194 	INTC_WRITE(sc, reg, pending);
    195 
    196 	if (pending == 0)
    197 		return 0;
    198 
    199 	return pic_mark_pending_sources(&sc->sc_pic, group * 32, pending);
    200 }
    201 
    202 static void
    203 am18xx_intc_irq_handler(void *frame)
    204 {
    205 	struct cpu_info * const ci = curcpu();
    206 	struct am18xx_intc_softc * const sc = intc_softc;
    207 	const int old_ipl = ci->ci_cpl;
    208 	const uint32_t oldipl_mask = __BIT(old_ipl);
    209 	int ipl_mask = 0;
    210 
    211 	ci->ci_data.cpu_nintr++;
    212 
    213 	for (int group = 0; group <= sc->sc_num_irqs/32; group++) {
    214 		ipl_mask |= find_pending_irqs(sc, group);
    215 	}
    216 
    217 	if ((ipl_mask & ~oldipl_mask) > oldipl_mask)
    218 		pic_do_pending_ints(I32_bit, old_ipl, frame);
    219 }
    220 
    221 /*
    222  * Enable interrupt according to the TRM section 11.3.2
    223  */
    224 static void am18xx_intc_enable_interrupts(struct am18xx_intc_softc *sc)
    225 {
    226 	/* disable interrupts */
    227 	INTC_WRITE(sc, AM18XX_AINTC_GER, 0);
    228 	INTC_WRITE(sc, AM18XX_AINTC_HIER, 0);
    229 
    230 	/* disable nesting and prioritization in CR */
    231 	INTC_WRITE(sc, AM18XX_AINTC_CR, 0);
    232 
    233 	/* disable all interrupts, clear their status */
    234 	for (int i = 0; i <= sc->sc_num_irqs / 32; i++) {
    235 		INTC_WRITE(sc, AM18XX_AINTC_ECR1 + 4 * i, 0xFFFFFFFF);
    236 		INTC_WRITE(sc, AM18XX_AINTC_SECR1 + 4 * i, 0xFFFFFFFF);
    237 	}
    238 
    239 	/* enable IRQ interrupts */
    240 	INTC_WRITE(sc, AM18XX_AINTC_HIER, AM18XX_AINTC_HIER_IRQ);
    241 
    242 	/* set enable bit in GER */
    243 	INTC_WRITE(sc, AM18XX_AINTC_GER, AM18XX_AINTC_GER_ENABLE);
    244 }
    245 
    246 int
    247 am18xx_intc_match(device_t parent, cfdata_t cf, void *aux)
    248 {
    249 	struct fdt_attach_args * const faa = aux;
    250 
    251 	return of_compatible_match(faa->faa_phandle, compat_data);
    252 }
    253 
    254 void
    255 am18xx_intc_attach(device_t parent, device_t self, void *aux)
    256 {
    257 	struct am18xx_intc_softc * const sc = device_private(self);
    258 	struct fdt_attach_args * const faa = aux;
    259 	const int phandle = faa->faa_phandle;
    260 	bus_addr_t addr;
    261 	bus_size_t size;
    262 	uint32_t maxsources;
    263 
    264 	sc->sc_bst = faa->faa_bst;
    265 	intc_softc = sc;
    266 
    267 	if (fdtbus_get_reg(phandle, 0, &addr, &size) != 0) {
    268 		aprint_error(": couldn't get registers\n");
    269 		return;
    270 	}
    271 	if (bus_space_map(sc->sc_bst, addr, size, 0, &sc->sc_bsh) != 0) {
    272 		aprint_error(": couldn't map registers\n");
    273 		return;
    274 	}
    275 
    276 	if (of_getprop_uint32(phandle, "ti,intc-size", &maxsources) != 0) {
    277 		aprint_error(": couldn't get max interrupt number\n");
    278 		return;
    279 	}
    280 	sc->sc_num_irqs = maxsources;
    281 
    282 	sc->sc_pic.pic_ops = &am18xx_intc_picops;
    283 	sc->sc_pic.pic_maxsources = maxsources;
    284 	strlcpy(sc->sc_pic.pic_name, device_xname(self),
    285 		sizeof(sc->sc_pic.pic_name));
    286 
    287 	pic_add(&sc->sc_pic, 0);
    288 	fdtbus_register_interrupt_controller(self, phandle,
    289 					     &am18xx_intc_fdt_funcs);
    290 
    291 	arm_fdt_irq_set_handler(am18xx_intc_irq_handler);
    292 	am18xx_intc_enable_interrupts(sc);
    293 
    294 	aprint_normal("\n");
    295 }
    296 
    297