1 /* $NetBSD: tegra_rtc.c,v 1.2 2015/12/13 17:39:19 jmcneill Exp $ */ 2 3 /*- 4 * Copyright (c) 2015 Jared D. McNeill <jmcneill@invisible.ca> 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 22 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #include <sys/cdefs.h> 30 __KERNEL_RCSID(0, "$NetBSD: tegra_rtc.c,v 1.2 2015/12/13 17:39:19 jmcneill Exp $"); 31 32 #include <sys/param.h> 33 #include <sys/bus.h> 34 #include <sys/device.h> 35 #include <sys/intr.h> 36 #include <sys/systm.h> 37 #include <sys/kernel.h> 38 #include <sys/kmem.h> 39 40 #include <dev/clock_subr.h> 41 42 #include <arm/nvidia/tegra_reg.h> 43 #include <arm/nvidia/tegra_rtcreg.h> 44 #include <arm/nvidia/tegra_var.h> 45 46 #include <dev/fdt/fdtvar.h> 47 48 static int tegra_rtc_match(device_t, cfdata_t, void *); 49 static void tegra_rtc_attach(device_t, device_t, void *); 50 51 struct tegra_rtc_softc { 52 device_t sc_dev; 53 bus_space_tag_t sc_bst; 54 bus_space_handle_t sc_bsh; 55 56 struct todr_chip_handle sc_todr; 57 }; 58 59 static int tegra_rtc_gettime(todr_chip_handle_t, struct timeval *); 60 static int tegra_rtc_settime(todr_chip_handle_t, struct timeval *); 61 62 CFATTACH_DECL_NEW(tegra_rtc, sizeof(struct tegra_rtc_softc), 63 tegra_rtc_match, tegra_rtc_attach, NULL, NULL); 64 65 #define RTC_READ(sc, reg) \ 66 bus_space_read_4((sc)->sc_bst, (sc)->sc_bsh, (reg)) 67 #define RTC_WRITE(sc, reg, val) \ 68 bus_space_write_4((sc)->sc_bst, (sc)->sc_bsh, (reg), (val)) 69 70 static int 71 tegra_rtc_match(device_t parent, cfdata_t cf, void *aux) 72 { 73 const char * const compatible[] = { "nvidia,tegra124-rtc", NULL }; 74 struct fdt_attach_args * const faa = aux; 75 76 return of_match_compatible(faa->faa_phandle, compatible); 77 } 78 79 static void 80 tegra_rtc_attach(device_t parent, device_t self, void *aux) 81 { 82 struct tegra_rtc_softc * const sc = device_private(self); 83 struct fdt_attach_args * const faa = aux; 84 bus_addr_t addr; 85 bus_size_t size; 86 int error; 87 88 if (fdtbus_get_reg(faa->faa_phandle, 0, &addr, &size) != 0) { 89 aprint_error(": couldn't get registers\n"); 90 return; 91 } 92 93 sc->sc_dev = self; 94 sc->sc_bst = faa->faa_bst; 95 error = bus_space_map(sc->sc_bst, addr, size, 0, &sc->sc_bsh); 96 if (error) { 97 aprint_error(": couldn't map %#llx: %d", (uint64_t)addr, error); 98 return; 99 } 100 101 aprint_naive("\n"); 102 aprint_normal(": RTC\n"); 103 104 sc->sc_todr.todr_gettime = tegra_rtc_gettime; 105 sc->sc_todr.todr_settime = tegra_rtc_settime; 106 sc->sc_todr.cookie = sc; 107 todr_attach(&sc->sc_todr); 108 } 109 110 static int 111 tegra_rtc_gettime(todr_chip_handle_t tch, struct timeval *tv) 112 { 113 struct tegra_rtc_softc * const sc = tch->cookie; 114 115 tv->tv_sec = RTC_READ(sc, RTC_SECONDS_REG); 116 tv->tv_usec = 0; 117 118 return 0; 119 } 120 121 static int 122 tegra_rtc_settime(todr_chip_handle_t tch, struct timeval *tv) 123 { 124 struct tegra_rtc_softc * const sc = tch->cookie; 125 int retry = 500; 126 127 while (--retry > 0) { 128 if ((RTC_READ(sc, RTC_BUSY_REG) & RTC_BUSY_STATUS) == 0) 129 break; 130 delay(1); 131 } 132 if (retry == 0) { 133 device_printf(sc->sc_dev, "RTC write failed (BUSY)\n"); 134 return ETIMEDOUT; 135 } 136 137 RTC_WRITE(sc, RTC_SECONDS_REG, tv->tv_sec); 138 139 return 0; 140 } 141