/* $NetBSD: pgtimer.c,v 1.1 2026/07/19 01:48:24 thorpej Exp $ */ /*- * Copyright (c) 2025 The NetBSD Foundation, Inc. * All rights reserved. * * This code is derived from software contributed to The NetBSD Foundation * by Jason R. Thorpe. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ #include __KERNEL_RCSID(0, "$NetBSD: pgtimer.c,v 1.1 2026/07/19 01:48:24 thorpej Exp $"); #include #include #include #include #include #include #include struct pgtimer_softc { device_t sc_dev; bus_space_tag_t sc_st; bus_space_handle_t sc_sh; uint32_t sc_reg_shift; void *sc_ih; uint32_t sc_freq; struct clock_attach_args sc_clock_args; void (*sc_handler)(struct clockframe *); struct evcnt *sc_evcnt; }; #define TIMER_CSR 0 #define CSR_ENAB __BIT(0) #define CSR_IPEND __BIT(1) #define TIMER_VAL 1 #define REG_OFF(sc, r) ((r) << (sc)->sc_reg_shift) #define REG_READ(sc, r) \ bus_space_read_1((sc)->sc_st, (sc)->sc_sh, REG_OFF((sc), (r))) #define REG_WRITE(sc, r, v) \ bus_space_write_1((sc)->sc_st, (sc)->sc_sh, REG_OFF((sc), (r)), (v)) static const struct device_compatible_entry compat_data[] = { { .compat = "pg68k,ioctl010-timer" }, DEVICE_COMPAT_EOL }; static uint32_t pgtimer_us_to_ticks(struct pgtimer_softc *sc, unsigned int interval_us) { const uint32_t tick_ns = 1000000000 / sc->sc_freq; const uint64_t interval_ns = interval_us * 1000; const uint64_t ticks = interval_ns / tick_ns; if (ticks == 0 || ticks > 0xffff) { panic("%s: impossible interval %u us (ticks=%llu)", __func__, interval_us, ticks); } return (uint32_t)ticks; } static void pgtimer_initclock(void *arg, unsigned int interval_us, struct evcnt *ev, void (*func)(struct clockframe *)) { struct pgtimer_softc *sc = arg; const uint32_t ticks = pgtimer_us_to_ticks(sc, interval_us); sc->sc_handler = func; sc->sc_evcnt = ev; /* * Changing the counter reload value implicitly disables the * timer. The reload value is set by writing the high byte * followed by the load byte to the Value register. The reload * value is unpredictable until both bytes have been written. */ REG_WRITE(sc, TIMER_VAL, (uint8_t)(ticks >> 8)); REG_WRITE(sc, TIMER_VAL, (uint8_t)ticks); REG_WRITE(sc, TIMER_CSR, CSR_ENAB); } #define CLOCK_HANDLER() \ do { \ /* Clear interrupt condition. */ \ REG_READ(sc, TIMER_CSR); \ \ /* Timer auto-reloads. */ \ \ /* Increment the counter and call the handler. */ \ sc->sc_evcnt->ev_count++; \ sc->sc_handler((struct clockframe *)v); \ } while (/*CONSTCOND*/0) static int pgtimer_hardclock(void *v) { struct pgtimer_softc *sc = clock_devices[CLOCK_HARDCLOCK]; CLOCK_HANDLER(); return 1; } static int pgtimer_statclock(void *v) { struct pgtimer_softc *sc = clock_devices[CLOCK_STATCLOCK]; CLOCK_HANDLER(); return 1; } static void *pgtimer_isrs[NCLOCKS] = { [CLOCK_HARDCLOCK] = pgtimer_hardclock, [CLOCK_STATCLOCK] = pgtimer_statclock, }; static int pgtimer_match(device_t parent, cfdata_t cf, void *aux) { struct fdt_attach_args * const faa = aux; return of_compatible_match(faa->faa_phandle, compat_data); } static void pgtimer_attach(device_t parent, device_t self, void *aux) { struct pgtimer_softc * const sc = device_private(self); struct fdt_attach_args * const faa = aux; const int phandle = faa->faa_phandle; bus_addr_t addr; bus_size_t size; char intrstr[128]; struct clk *clk; uint32_t clk_div; int which, error; sc->sc_dev = self; sc->sc_st = faa->faa_bst; if (fdtbus_get_reg(phandle, 0, &addr, &size) != 0) { aprint_error(": couldn't get registers\n"); return; } if (of_getprop_uint32(phandle, "reg-shift", &sc->sc_reg_shift)) { /* missing or bad reg-shift property, assume 0 */ sc->sc_reg_shift = 0; } error = bus_space_map(sc->sc_st, addr, size, 0, &sc->sc_sh); if (error) { aprint_error(": couldn't map registers (error=%d)\n", error); return; } /* Make sure the timer is disabled. */ REG_WRITE(sc, TIMER_CSR, 0); clk = fdtbus_clock_get_index(phandle, 0); if (clk == NULL) { aprint_error(": couldn't get clock handle\n"); return; } if (!fdtbus_intr_str(phandle, 0, intrstr, sizeof(intrstr))) { aprint_error(": failed to decode interrupt\n"); return; } /* * The input to the I/O controller is the main system clock, * which the timer divides itself internally. Firmware will * provide this value in the device tree. */ if (of_getprop_uint32(phandle, "clock-div", &clk_div)) { /* default to divide-by-16 */ clk_div = 16; } sc->sc_freq = clk_get_rate(clk) / clk_div; aprint_naive("\n"); aprint_normal(": frequency %u Hz\n", sc->sc_freq); which = clock_from_phandle(phandle); if (which == CLOCK_NONE || pgtimer_isrs[which] == NULL) { return; } sc->sc_ih = fdtbus_intr_establish_xname(phandle, 0, IPL_SCHED, FDT_INTR_MPSAFE, pgtimer_isrs[which], NULL, device_xname(self)); if (sc->sc_ih == NULL) { aprint_error_dev(self, "failed to establish interrupt at %s\n", intrstr); return; } aprint_normal_dev(self, "interrupting at %s\n", intrstr); sc->sc_clock_args.ca_initfunc = pgtimer_initclock; sc->sc_clock_args.ca_arg = sc; sc->sc_clock_args.ca_which = which; clock_attach(self, &sc->sc_clock_args); } CFATTACH_DECL_NEW(pgtimer, sizeof(struct pgtimer_softc), pgtimer_match, pgtimer_attach, NULL, NULL);