jh7110_wdt.c revision 1.1
1 /* $NetBSD: jh7110_wdt.c,v 1.1 2026/08/25 20:46:17 riz 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 Jeffrey C. Rizzo 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: jh7110_wdt.c,v 1.1 2026/08/25 20:46:17 riz Exp $"); 34 35 #include <sys/param.h> 36 #include <sys/bus.h> 37 #include <sys/device.h> 38 #include <sys/systm.h> 39 #include <sys/wdog.h> 40 41 #include <dev/sysmon/sysmonvar.h> 42 43 #include <dev/fdt/fdtvar.h> 44 45 /* 46 * The JH7110 WDT appears to be a clone of the ARM SP805 watchdog module. 47 * 48 * Register definitions and operating principles were taken from the 49 * ARM Watchdog Module (SP805) Technical Reference Manual, retrieved from 50 * https://community.arm.com/cfs-file/__key/communityserver-discussions-components-files/468/DDI0270-_2800_4_2900_-2-_2800_1_2900_.pdf 51 * 52 */ 53 54 #define JH7110_WDT_PERIOD_DEFAULT 15 55 56 #define JH7110_WDT_LOAD 0x00 57 #define JH7110_WDT_VALUE 0x04 58 #define JH7110_WDT_CONTROL 0x08 59 #define JH7110_WDT_CONTROL_INTEN __BIT(0) 60 #define JH7110_WDT_CONTROL_RESEN __BIT(1) 61 62 #define JH7110_WDT_INTCLR 0x0c 63 #define JH7110_WDT_MIS 0x14 64 65 #define JH7110_WDT_LOCK 0xc00 66 #define JH7110_WDT_UNLOCK_KEY 0x1ACCE551 67 68 #define JH7110_WDT_PERIPHID0 0xfe0 69 #define JH7110_WDT_PERIPHID1 0xfe4 70 #define JH7110_WDT_PERIPHID2 0xfe8 71 #define JH7110_WDT_PERIPHID3 0xfec 72 #define JH7110_WDT_PCELLID0 0xff0 73 #define JH7110_WDT_PCELLID1 0xff4 74 #define JH7110_WDT_PCELLID2 0xff8 75 #define JH7110_WDT_PCELLID3 0xffc 76 77 enum { 78 JH7110_WDT_CLK_APB = 0, 79 JH7110_WDT_CLK_CORE = 1, 80 }; 81 82 static const struct device_compatible_entry compat_data[] = { 83 { .compat = "starfive,jh7110-wdt" }, 84 DEVICE_COMPAT_EOL 85 }; 86 87 struct jh7110_wdt_softc { 88 device_t sc_dev; 89 bus_space_tag_t sc_bst; 90 bus_space_handle_t sc_bsh; 91 92 struct sysmon_wdog sc_smw; 93 u_int sc_rate; 94 }; 95 96 static inline uint32_t 97 jh7110_wdt_read(struct jh7110_wdt_softc *sc, bus_size_t reg) 98 { 99 return bus_space_read_4(sc->sc_bst, sc->sc_bsh, reg); 100 } 101 102 static inline void 103 jh7110_wdt_write(struct jh7110_wdt_softc *sc, bus_size_t reg, uint32_t val) 104 { 105 bus_space_write_4(sc->sc_bst, sc->sc_bsh, reg, val); 106 } 107 108 static void 109 jh7110_wdt_stop(struct jh7110_wdt_softc *sc) 110 { 111 jh7110_wdt_write(sc, JH7110_WDT_LOCK, JH7110_WDT_UNLOCK_KEY); 112 113 uint32_t val = jh7110_wdt_read(sc, JH7110_WDT_CONTROL); 114 jh7110_wdt_write(sc, JH7110_WDT_CONTROL, val & ~JH7110_WDT_CONTROL_INTEN); 115 116 jh7110_wdt_write(sc, JH7110_WDT_LOCK, 1); 117 } 118 119 static void 120 jh7110_wdt_start(struct jh7110_wdt_softc *sc, uint32_t count) 121 { 122 jh7110_wdt_write(sc, JH7110_WDT_LOCK, JH7110_WDT_UNLOCK_KEY); 123 124 uint32_t val = jh7110_wdt_read(sc, JH7110_WDT_CONTROL); 125 jh7110_wdt_write(sc, JH7110_WDT_CONTROL, val & ~JH7110_WDT_CONTROL_INTEN); 126 val = jh7110_wdt_read(sc, JH7110_WDT_CONTROL); 127 jh7110_wdt_write(sc, JH7110_WDT_CONTROL, val | JH7110_WDT_CONTROL_RESEN); 128 jh7110_wdt_write(sc, JH7110_WDT_INTCLR, 1); 129 jh7110_wdt_write(sc, JH7110_WDT_LOAD, count); 130 val = jh7110_wdt_read(sc, JH7110_WDT_CONTROL); 131 jh7110_wdt_write(sc, JH7110_WDT_CONTROL, val | JH7110_WDT_CONTROL_INTEN); 132 133 jh7110_wdt_write(sc, JH7110_WDT_LOCK, 1); 134 } 135 136 static int 137 jh7110_wdt_setmode(struct sysmon_wdog *smw) 138 { 139 struct jh7110_wdt_softc * const sc = smw->smw_cookie; 140 141 if ((smw->smw_mode & WDOG_MODE_MASK) == WDOG_MODE_DISARMED) { 142 jh7110_wdt_stop(sc); 143 return 0; 144 } 145 146 if (smw->smw_period == WDOG_PERIOD_DEFAULT) 147 sc->sc_smw.smw_period = JH7110_WDT_PERIOD_DEFAULT; 148 else 149 sc->sc_smw.smw_period = smw->smw_period; 150 151 if (sc->sc_smw.smw_period == 0) { 152 jh7110_wdt_stop(sc); 153 } else { 154 /* wdt counts down twice before resetting, so halve rate */ 155 uint32_t counter = sc->sc_smw.smw_period * sc->sc_rate / 2; 156 jh7110_wdt_start(sc, (uint32_t)counter); 157 } 158 159 return 0; 160 } 161 162 static int 163 jh7110_wdt_tickle(struct sysmon_wdog *smw) 164 { 165 struct jh7110_wdt_softc * const sc = smw->smw_cookie; 166 167 jh7110_wdt_write(sc, JH7110_WDT_LOCK, JH7110_WDT_UNLOCK_KEY); 168 169 jh7110_wdt_write(sc, JH7110_WDT_INTCLR, 1); 170 171 jh7110_wdt_write(sc, JH7110_WDT_LOCK, 1); 172 return 0; 173 } 174 175 static int 176 jh7110_wdt_match(device_t parent, cfdata_t cf, void *aux) 177 { 178 struct fdt_attach_args * const faa = aux; 179 180 return of_compatible_match(faa->faa_phandle, compat_data); 181 } 182 183 static void 184 jh7110_wdt_attach(device_t parent, device_t self, void *aux) 185 { 186 struct jh7110_wdt_softc * const sc = device_private(self); 187 struct fdt_attach_args * const faa = aux; 188 const int phandle = faa->faa_phandle; 189 bus_addr_t addr; 190 bus_size_t size; 191 int error; 192 193 if (fdtbus_get_reg(phandle, 0, &addr, &size) != 0) { 194 aprint_error(": couldn't get registers\n"); 195 return; 196 } 197 198 sc->sc_dev = self; 199 sc->sc_bst = faa->faa_bst; 200 error = bus_space_map(sc->sc_bst, addr, size, 0, &sc->sc_bsh); 201 if (error) { 202 aprint_error(": couldn't map %#" PRIxBUSADDR ": %d", addr, 203 error); 204 return; 205 } 206 207 struct { 208 const char *jwc_name; 209 u_int jwc_rate; 210 } jh7110_wdt_clk[] = { 211 [JH7110_WDT_CLK_APB] = { 212 .jwc_name = "apb", 213 }, 214 [JH7110_WDT_CLK_CORE] = { 215 .jwc_name = "core", 216 }, 217 }; 218 for (size_t i = 0; i < __arraycount(jh7110_wdt_clk); i++) { 219 const char *cr = jh7110_wdt_clk[i].jwc_name; 220 221 struct clk *clk = fdtbus_clock_get(phandle, cr); 222 if (clk == NULL) { 223 aprint_error(": couldn't get clock '%s'\n", cr); 224 return; 225 } 226 error = clk_enable(clk); 227 if (error) { 228 aprint_error(": couldn't enable clock '%s'\n", cr); 229 return; 230 } 231 u_int rate = clk_get_rate(clk); 232 if (rate == 0) { 233 aprint_error(": couldn't get rate for clock '%s'\n", cr); 234 return; 235 } 236 jh7110_wdt_clk[i].jwc_rate = rate; 237 } 238 239 /* de-assert resets */ 240 struct fdtbus_reset *rst; 241 for (u_int n = 0; (rst = fdtbus_reset_get_index(phandle, n)) != NULL; n++) { 242 if (fdtbus_reset_deassert(rst) != 0) { 243 aprint_error(": couldn't de-assert reset #%d\n", n); 244 return; 245 } 246 } 247 248 sc->sc_rate = jh7110_wdt_clk[JH7110_WDT_CLK_CORE].jwc_rate; 249 250 aprint_naive("\n"); 251 aprint_normal(": watchdog\n"); 252 253 sc->sc_smw.smw_name = device_xname(self); 254 sc->sc_smw.smw_cookie = sc; 255 sc->sc_smw.smw_setmode = jh7110_wdt_setmode; 256 sc->sc_smw.smw_tickle = jh7110_wdt_tickle; 257 sc->sc_smw.smw_period = JH7110_WDT_PERIOD_DEFAULT; 258 sysmon_wdog_register(&sc->sc_smw); 259 } 260 261 CFATTACH_DECL_NEW(jh7110_wdt, sizeof(struct jh7110_wdt_softc), 262 jh7110_wdt_match, jh7110_wdt_attach, NULL, NULL); 263
Indexes created Mon Oct 26 00:26:21 UTC 2026