1 /* $Id: imx23_rtc.c,v 1.2 2019/10/18 04:09:01 msaitoh Exp $ */ 2 3 /* 4 * Copyright (c) 2014 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/types.h> 34 #include <sys/bus.h> 35 #include <sys/cdefs.h> 36 #include <sys/device.h> 37 #include <sys/errno.h> 38 39 #include <arm/imx/imx23_rtcreg.h> 40 #include <arm/imx/imx23_rtcvar.h> 41 #include <arm/imx/imx23var.h> 42 43 typedef struct rtc_softc { 44 device_t sc_dev; 45 bus_space_tag_t sc_iot; 46 bus_space_handle_t sc_hdl; 47 } *rtc_softc_t; 48 49 static int rtc_match(device_t, cfdata_t, void *); 50 static void rtc_attach(device_t, device_t, void *); 51 static int rtc_activate(device_t, enum devact); 52 53 static void rtc_init(struct rtc_softc *); 54 static void rtc_reset(struct rtc_softc *); 55 56 static rtc_softc_t _sc = NULL; 57 58 CFATTACH_DECL3_NEW(rtc, 59 sizeof(struct rtc_softc), 60 rtc_match, 61 rtc_attach, 62 NULL, 63 rtc_activate, 64 NULL, 65 NULL, 66 0 67 ); 68 69 #define RTC_RD(sc, reg) \ 70 bus_space_read_4(sc->sc_iot, sc->sc_hdl, (reg)) 71 #define RTC_WR(sc, reg, val) \ 72 bus_space_write_4(sc->sc_iot, sc->sc_hdl, (reg), (val)) 73 74 #define RTC_SOFT_RST_LOOP 455 /* At least 1 us ... */ 75 76 static int 77 rtc_match(device_t parent, cfdata_t match, void *aux) 78 { 79 struct apb_attach_args *aa = aux; 80 81 if ((aa->aa_addr == HW_RTC_BASE) && 82 (aa->aa_size == HW_RTC_BASE_SIZE)) 83 return 1; 84 85 return 0; 86 } 87 88 static void 89 rtc_attach(device_t parent, device_t self, void *aux) 90 { 91 struct rtc_softc *sc = device_private(self); 92 struct apb_attach_args *aa = aux; 93 static int rtc_attached = 0; 94 95 sc->sc_dev = self; 96 sc->sc_iot = aa->aa_iot; 97 98 if (rtc_attached) { 99 aprint_error_dev(sc->sc_dev, "rtc is already attached\n"); 100 return; 101 } 102 103 if (bus_space_map(sc->sc_iot, aa->aa_addr, aa->aa_size, 0, 104 &sc->sc_hdl)) 105 { 106 aprint_error_dev(sc->sc_dev, "Unable to map bus space\n"); 107 return; 108 } 109 110 111 rtc_init(sc); 112 rtc_reset(sc); 113 114 aprint_normal("\n"); 115 116 rtc_attached = 1; 117 118 return; 119 } 120 121 static int 122 rtc_activate(device_t self, enum devact act) 123 { 124 125 return EOPNOTSUPP; 126 } 127 128 static void 129 rtc_init(struct rtc_softc *sc) 130 { 131 _sc = sc; 132 return; 133 } 134 135 /* 136 * Remove pulldown resistors on the headphone outputs. 137 */ 138 void 139 rtc_release_gnd(int val) 140 { 141 struct rtc_softc *sc = _sc; 142 143 if (sc == NULL) { 144 aprint_error("rtc is not initialized"); 145 return; 146 } 147 if(val) 148 RTC_WR(sc, HW_RTC_PERSISTENT0_SET, (1<<19)); 149 else 150 RTC_WR(sc, HW_RTC_PERSISTENT0_CLR, (1<<19)); 151 152 return; 153 } 154 155 /* 156 * Reset the RTC block. 157 * 158 * Inspired by i.MX23 RM "39.3.10 Correct Way to Soft Reset a Block" 159 */ 160 static void 161 rtc_reset(struct rtc_softc *sc) 162 { 163 unsigned int loop; 164 165 /* Prepare for soft-reset by making sure that SFTRST is not currently 166 * asserted. Also clear CLKGATE so we can wait for its assertion below. 167 */ 168 RTC_WR(sc, HW_RTC_CTRL_CLR, HW_RTC_CTRL_SFTRST); 169 170 /* Wait at least a microsecond for SFTRST to deassert. */ 171 loop = 0; 172 while ((RTC_RD(sc, HW_RTC_CTRL) & HW_RTC_CTRL_SFTRST) || 173 (loop < RTC_SOFT_RST_LOOP)) 174 loop++; 175 176 /* Clear CLKGATE so we can wait for its assertion below. */ 177 RTC_WR(sc, HW_RTC_CTRL_CLR, HW_RTC_CTRL_CLKGATE); 178 179 /* Soft-reset the block. */ 180 RTC_WR(sc, HW_RTC_CTRL_SET, HW_RTC_CTRL_SFTRST); 181 182 /* Wait until clock is in the gated state. */ 183 while (!(RTC_RD(sc, HW_RTC_CTRL) & HW_RTC_CTRL_CLKGATE)); 184 185 /* Bring block out of reset. */ 186 RTC_WR(sc, HW_RTC_CTRL_CLR, HW_RTC_CTRL_SFTRST); 187 188 loop = 0; 189 while ((RTC_RD(sc, HW_RTC_CTRL) & HW_RTC_CTRL_SFTRST) || 190 (loop < RTC_SOFT_RST_LOOP)) 191 loop++; 192 193 RTC_WR(sc, HW_RTC_CTRL_CLR, HW_RTC_CTRL_CLKGATE); 194 195 /* Wait until clock is in the NON-gated state. */ 196 while (RTC_RD(sc, HW_RTC_CTRL) & HW_RTC_CTRL_CLKGATE); 197 198 return; 199 } 200
Indexes created Fri Sep 26 08:10:20 GMT 2025