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      1 /*	$NetBSD: wrap030_timer.c,v 1.2 2026/08/07 23:37:46 thorpej Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2026 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Jason R. Thorpe.
      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/cdefs.h>
     33 __KERNEL_RCSID(0, "$NetBSD: wrap030_timer.c,v 1.2 2026/08/07 23:37:46 thorpej Exp $");
     34 
     35 #include <sys/param.h>
     36 #include <sys/bus.h>
     37 #include <sys/device.h>
     38 #include <sys/intr.h>
     39 #include <sys/systm.h>
     40 
     41 #include <machine/clockvar.h>
     42 
     43 #include <dev/fdt/fdtvar.h>
     44 
     45 struct wraptmr_softc {
     46 	device_t	sc_dev;
     47 	bus_space_tag_t	sc_st;
     48 	bus_space_handle_t sc_sh;
     49 	void		*sc_ih;
     50 	uint32_t	sc_freq;
     51 	uint32_t	sc_reload;
     52 	struct clock_if sc_clkif;
     53 };
     54 
     55 #define	TIMER_ARM(sc)							\
     56 	bus_space_write_1((sc)->sc_st, (sc)->sc_sh, (sc)->sc_reload, 0)
     57 #define	TIMER_DISARM(sc)						\
     58 	bus_space_write_1((sc)->sc_st, (sc)->sc_sh, 0, 0)
     59 
     60 static const struct device_compatible_entry compat_data[] = {
     61 	{ .compat = "techav,wrap030-timer" },
     62 	DEVICE_COMPAT_EOL
     63 };
     64 
     65 static uint32_t
     66 wraptmr_us_to_ticks(struct wraptmr_softc *sc, unsigned int interval_us)
     67 {
     68 	const uint32_t tick_ns = 1000000000 / sc->sc_freq;
     69 	const uint64_t interval_ns = interval_us * 1000;
     70 	const uint64_t ticks = interval_ns / tick_ns;
     71 
     72 	if (ticks == 0 || ticks > 0xffff) {
     73 		panic("%s: impossible interval %u us (ticks=%llu)", __func__,
     74 		    interval_us, ticks);
     75 	}
     76 
     77 	return (uint32_t)ticks;
     78 }
     79 
     80 static int
     81 wraptmr_init(struct clock_if *clk, int (*intrfunc)(void *))
     82 {
     83 	struct wraptmr_softc *sc =
     84 	    container_of(clk, struct wraptmr_softc, sc_clkif);
     85 	int phandle = devhandle_to_of(device_handle(sc->sc_dev));
     86 	char intrstr[128];
     87 
     88 	KASSERT(sc->sc_dev == clk->clk_dev);
     89 
     90 	if (!fdtbus_intr_str(phandle, 0, intrstr, sizeof(intrstr))) {
     91 		aprint_error_dev(sc->sc_dev, "failed to decode interrupt\n");
     92 		return ENXIO;
     93 	}
     94 
     95 	sc->sc_ih = fdtbus_intr_establish_xname(phandle, 0, IPL_SCHED,
     96 	    FDT_INTR_MPSAFE, intrfunc, NULL, device_xname(sc->sc_dev));
     97 	if (sc->sc_ih == NULL) {
     98 		aprint_error_dev(sc->sc_dev,
     99 		    "failed to establish interrupt at %s\n", intrstr);
    100 		return ENXIO;
    101 	}
    102 	aprint_normal_dev(sc->sc_dev, "interrupting at %s\n", intrstr);
    103 
    104 	return 0;
    105 }
    106 
    107 static int
    108 wraptmr_arm(struct clock_if *clk, unsigned int interval_us)
    109 {
    110 	struct wraptmr_softc *sc =
    111 	    container_of(clk, struct wraptmr_softc, sc_clkif);
    112 
    113 	sc->sc_reload = wraptmr_us_to_ticks(sc, interval_us);
    114 	TIMER_ARM(sc);
    115 
    116 	return 0;
    117 }
    118 
    119 static void
    120 wraptmr_intr(struct clock_if *clk)
    121 {
    122 	struct wraptmr_softc *sc =
    123 	    container_of(clk, struct wraptmr_softc, sc_clkif);
    124 
    125 	TIMER_ARM(sc);
    126 }
    127 
    128 static void
    129 wraptmr_disarm(struct clock_if *clk)
    130 {
    131 	struct wraptmr_softc *sc =
    132 	    container_of(clk, struct wraptmr_softc, sc_clkif);
    133 
    134 	TIMER_DISARM(sc);
    135 }
    136 
    137 static int
    138 wraptmr_match(device_t parent, cfdata_t cf, void *aux)
    139 {
    140 	struct fdt_attach_args * const faa = aux;
    141 
    142 	return of_compatible_match(faa->faa_phandle, compat_data);
    143 }
    144 
    145 static void
    146 wraptmr_attach(device_t parent, device_t self, void *aux)
    147 {
    148 	struct wraptmr_softc * const sc = device_private(self);
    149 	struct fdt_attach_args * const faa = aux;
    150 	const int phandle = faa->faa_phandle;
    151 	bus_addr_t addr;
    152 	bus_size_t size;
    153 	struct clk *clk;
    154 	int error;
    155 
    156 	sc->sc_dev = self;
    157 	sc->sc_st = faa->faa_bst;
    158 
    159 	if (fdtbus_get_reg(phandle, 0, &addr, &size) != 0) {
    160 		aprint_error(": couldn't get registers\n");
    161 		return;
    162 	}
    163 
    164 	error = bus_space_map(sc->sc_st, addr, size, 0, &sc->sc_sh);
    165 	if (error) {
    166 		aprint_error(": couldn't map registers (error=%d)\n", error);
    167 		return;
    168 	}
    169 
    170 	/* Make sure the timer is disabled. */
    171 	TIMER_DISARM(sc);
    172 
    173 	clk = fdtbus_clock_get_index(phandle, 0);
    174 	if (clk == NULL) {
    175 		aprint_error(": couldn't get clock handle\n");
    176 		return;
    177 	}
    178 
    179 	sc->sc_freq = clk_get_rate(clk);
    180 
    181 	aprint_naive("\n");
    182 	aprint_normal(": frequency %u Hz\n", sc->sc_freq);
    183 
    184 	sc->sc_clkif.clk_dev = self;
    185 	sc->sc_clkif.clk_init = wraptmr_init;
    186 	sc->sc_clkif.clk_arm = wraptmr_arm;
    187 	sc->sc_clkif.clk_intr = wraptmr_intr;
    188 	sc->sc_clkif.clk_disarm = wraptmr_disarm;
    189 	clock_attach(&sc->sc_clkif);
    190 }
    191 
    192 CFATTACH_DECL_NEW(wraptmr, sizeof(struct wraptmr_softc),
    193     wraptmr_match, wraptmr_attach, NULL, NULL);
    194