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      1 /*	$NetBSD: imxsnvs.c,v 1.3 2025/09/07 21:45:11 thorpej Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 2014 Ryo Shimizu
      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
     18  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
     19  * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
     20  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
     21  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
     22  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
     24  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
     25  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     26  * POSSIBILITY OF SUCH DAMAGE.
     27  */
     28 
     29 /*
     30  * i.MX6,7 Secure Non-Volatile Storage
     31  */
     32 #include <sys/cdefs.h>
     33 __KERNEL_RCSID(0, "$NetBSD: imxsnvs.c,v 1.3 2025/09/07 21:45:11 thorpej Exp $");
     34 
     35 #include "locators.h"
     36 #include <sys/bus.h>
     37 #include <sys/device.h>
     38 #include <sys/param.h>
     39 #include <dev/clock_subr.h>
     40 
     41 #include <arm/imx/imxsnvsreg.h>
     42 #include <arm/imx/imxsnvsvar.h>
     43 
     44 struct imxsnvs_softc {
     45 	device_t sc_dev;
     46 	bus_space_tag_t sc_iot;
     47 	bus_space_handle_t sc_ioh;
     48 	struct todr_chip_handle sc_todr;
     49 };
     50 
     51 #define SNVS_READ(sc, reg)					\
     52 	bus_space_read_4((sc)->sc_iot, (sc)->sc_ioh, reg)
     53 
     54 #define SNVS_WRITE(sc, reg, val)				\
     55 	bus_space_write_4((sc)->sc_iot, (sc)->sc_ioh, reg, val)
     56 
     57 static int imxsnvs_rtc_enable(struct imxsnvs_softc *);
     58 static int imxsnvs_rtc_disable(struct imxsnvs_softc *);
     59 static int imxsnvs_gettime(todr_chip_handle_t, struct timeval *);
     60 static int imxsnvs_settime(todr_chip_handle_t, struct timeval *);
     61 
     62 
     63 CFATTACH_DECL_NEW(imxsnvs, sizeof(struct imxsnvs_softc),
     64     imxsnvs_match, imxsnvs_attach, NULL, NULL);
     65 
     66 /* ARGSUSED */
     67 int
     68 imxsnvs_attach_common(device_t parent __unused, device_t self,
     69                       bus_space_tag_t iot, paddr_t iobase, size_t size,
     70                       int intr __unused, int flags __unused)
     71 {
     72 	struct imxsnvs_softc *sc;
     73 	uint32_t v1, v2;
     74 
     75 	sc = device_private(self);
     76 	sc->sc_dev = self;
     77 	sc->sc_iot = iot;
     78 
     79 	aprint_naive("\n");
     80 	aprint_normal(": Secure Non-Volatile Storage\n");
     81 	if (bus_space_map(sc->sc_iot, iobase, size, 0,
     82 	    &sc->sc_ioh)) {
     83 		aprint_error_dev(self, "Cannot map registers\n");
     84 		return 1;
     85 	}
     86 
     87 	v1 = SNVS_READ(sc, SNVS_HPVIDR1);
     88 	v2 = SNVS_READ(sc, SNVS_HPVIDR2);
     89 	aprint_verbose_dev(self, "id=0x%llx, ver=%lld.%lld, ip_era=0x%llx, "
     90 	    "intg_opt=0x%llx, eco_rev=0x%llx, config_opt=0x%llx\n",
     91 	    __SHIFTOUT(v1, SNVS_HPVIDR1_IP_ID),
     92 	    __SHIFTOUT(v1, SNVS_HPVIDR1_MAJOR_REV),
     93 	    __SHIFTOUT(v1, SNVS_HPVIDR1_MINOR_REV),
     94 	    __SHIFTOUT(v2, SNVS_HPVIDR2_IP_ERA),
     95 	    __SHIFTOUT(v2, SNVS_HPVIDR2_INTG_OPT),
     96 	    __SHIFTOUT(v2, SNVS_HPVIDR2_ECO_REV),
     97 	    __SHIFTOUT(v2, SNVS_HPVIDR2_CONFIG_OPT));
     98 
     99 	if (imxsnvs_rtc_enable(sc) != 0) {
    100 		aprint_error_dev(self, "cannot enable RTC\n");
    101 		return 1;
    102 	}
    103 
    104 	sc->sc_todr.todr_gettime = imxsnvs_gettime;
    105 	sc->sc_todr.todr_settime = imxsnvs_settime;
    106 	sc->sc_todr.todr_dev = self;
    107 	todr_attach(&sc->sc_todr);
    108 
    109 	return 0;
    110 }
    111 
    112 static int
    113 imxsnvs_rtc_enable(struct imxsnvs_softc *sc)
    114 {
    115 	uint32_t v;
    116 	int timeout;
    117 
    118 	/* enable SRTC */
    119 	v = SNVS_READ(sc, SNVS_LPCR);
    120 	SNVS_WRITE(sc, SNVS_LPCR, v | SNVS_LPCR_SRTC_ENV);
    121 	for (timeout = 10000; timeout > 0; timeout--) {
    122 		if (SNVS_READ(sc, SNVS_LPCR) & SNVS_LPCR_SRTC_ENV)
    123 			break;
    124 	}
    125 	if (timeout == 0)
    126 		return ETIMEDOUT;
    127 
    128 	return 0;
    129 }
    130 
    131 static int
    132 imxsnvs_rtc_disable(struct imxsnvs_softc *sc)
    133 {
    134 	uint32_t v;
    135 	int timeout;
    136 
    137 	/* disable SRTC */
    138 	v = SNVS_READ(sc, SNVS_LPCR);
    139 	SNVS_WRITE(sc, SNVS_LPCR, v & ~SNVS_LPCR_SRTC_ENV);
    140 	for (timeout = 10000; timeout > 0; timeout--) {
    141 		if (!(SNVS_READ(sc, SNVS_LPCR) & SNVS_LPCR_SRTC_ENV))
    142 			break;
    143 	}
    144 	if (timeout == 0)
    145 		return ETIMEDOUT;
    146 
    147 	return 0;
    148 }
    149 
    150 static int
    151 imxsnvs_gettime(todr_chip_handle_t tch, struct timeval *tvp)
    152 {
    153 	struct imxsnvs_softc *sc = device_private(tch->todr_dev);
    154 	uint64_t c1, c2;
    155 
    156 	c2 = ((uint64_t)SNVS_READ(sc, SNVS_LPSRTCMR) << 32) +
    157 	    SNVS_READ(sc, SNVS_LPSRTCLR);
    158 	do {
    159 		c1 = c2;
    160 		c2 = ((uint64_t)SNVS_READ(sc, SNVS_LPSRTCMR) << 32) +
    161 		    SNVS_READ(sc, SNVS_LPSRTCLR);
    162 	} while (c1 != c2);
    163 
    164 	tvp->tv_sec = c1 >> SVNS_COUNTER_SHIFT;
    165 	tvp->tv_usec = (c1 % SVNS_COUNTER_HZ) * 1000000 / SVNS_COUNTER_HZ;
    166 
    167 	return 0;
    168 }
    169 
    170 static int
    171 imxsnvs_settime(todr_chip_handle_t tch, struct timeval *tvp)
    172 {
    173 	struct imxsnvs_softc *sc = device_private(tch->todr_dev);
    174 	uint64_t c, h, l;
    175 	int rv;
    176 
    177 	c = (uint64_t)tvp->tv_sec * SVNS_COUNTER_HZ +
    178 	    (uint64_t)tvp->tv_usec * SVNS_COUNTER_HZ / 1000000;
    179 	h = __SHIFTIN((c >> 32) & SNVS_LPSRTCMR_SRTC, SNVS_LPSRTCMR_SRTC);
    180 	l = c & 0xffffffff;
    181 
    182 	if ((rv = imxsnvs_rtc_disable(sc)) != 0)
    183 		return rv;
    184 
    185 	SNVS_WRITE(sc, SNVS_LPSRTCMR, h);
    186 	SNVS_WRITE(sc, SNVS_LPSRTCLR, l);
    187 
    188 	if ((rv = imxsnvs_rtc_enable(sc)) != 0)
    189 		return rv;
    190 
    191 	return 0;
    192 }
    193