Home | History | Annotate | Line # | Download | only in starfive
      1 /* $NetBSD: jh7110_trng.c,v 1.2 2025/02/09 09:09:49 skrll Exp $ */
      2 
      3 /*-
      4  * Copyright (c) 2025 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Nick Hudson
      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_trng.c,v 1.2 2025/02/09 09:09:49 skrll Exp $");
     34 
     35 #include <sys/param.h>
     36 
     37 #include <sys/bus.h>
     38 #include <sys/device.h>
     39 #include <sys/condvar.h>
     40 #include <sys/mutex.h>
     41 #include <sys/rndsource.h>
     42 
     43 #include <dev/fdt/fdtvar.h>
     44 
     45 
     46 struct jh7110_trng_softc {
     47 	device_t		sc_dev;
     48 	bus_space_tag_t		sc_bst;
     49 	bus_space_handle_t	sc_bsh;
     50 	int			sc_phandle;
     51 
     52 	kmutex_t		sc_lock;
     53 	kcondvar_t		sc_cv;
     54 	void *			sc_ih;
     55 	bool			sc_reseeddone;
     56 	size_t			sc_bytes_wanted;
     57 
     58 	krndsource_t		sc_rndsource;
     59 };
     60 
     61 
     62 #define RD4(sc, reg)							       \
     63 	bus_space_read_4((sc)->sc_bst, (sc)->sc_bsh, (reg))
     64 #define WR4(sc, reg, val)						       \
     65 	bus_space_write_4((sc)->sc_bst, (sc)->sc_bsh, (reg), (val))
     66 
     67 
     68 /* Register definitions */
     69 // https://doc-en.rvspace.org/JH7110/TRM/JH7110_TRM/control_registers_trng.html?hl=trng
     70 #define JH7110_TRNG_CTRL		0x0000
     71 #define  JH7110_TRNG_CTRL_NOP			0x0
     72 #define  JH7110_TRNG_CTRL_RANDOMIZE		0x1
     73 #define  JH7110_TRNG_CTRL_RANDOM_RESEED		0x2
     74 #define  JH7110_TRNG_CTRL_NONCE_RESEED		0x3
     75 #define JH7110_TRNG_STAT		0x0004
     76 #define  JH7110_TRNG_STAT_SEEDED		__BIT(9)
     77 
     78 #define JH7110_TRNG_MODE		0x0008
     79 #define  JH7110_TRNG_MODE_R256			__BIT(3)
     80 #define JH7110_TRNG_SMODE		0x000c
     81 #define JH7110_TRNG_IENABLE		0x0010
     82 #define  JH7110_TRNG_IENABLE_GLOBAL		__BIT(31)
     83 #define  JH7110_TRNG_IENABLE_LFSR_LOCKUP	__BIT(4)
     84 #define  JH7110_TRNG_IENABLE_RQST_LOCKUP	__BIT(3)
     85 #define  JH7110_TRNG_IENABLE_AGE_ALARM		__BIT(2)
     86 #define  JH7110_TRNG_IENABLE_SEED_DONE		__BIT(1)
     87 #define  JH7110_TRNG_IENABLE_RAND_RDY		__BIT(0)
     88 #define JH7110_TRNG_ISTATUS		0x0014
     89 #define  JH7110_TRNG_ISTATUS_LFSR_LOCKUP	__BIT(4)
     90 #define  JH7110_TRNG_ISTATUS_RQST_LOCKUP	__BIT(3)
     91 #define  JH7110_TRNG_ISTATUS_AGE_ALARM		__BIT(2)
     92 #define  JH7110_TRNG_ISTATUS_SEED_DONE		__BIT(1)
     93 #define  JH7110_TRNG_ISTATUS_RAND_RDY		__BIT(0)
     94 #define JH7110_TRNG_FEATURES		0x001c
     95 #define  JH7110_TRNG_FEATURES_MM_RESET_STATE	__BIT(3)
     96 #define  JH7110_TRNG_FEATURES_RAND_SEED_AVAIL	__BIT(2)
     97 #define  JH7110_TRNG_FEATURES_MAX_RAND_LENGTH	__BITS(1,0)
     98 
     99 #define  JH7110_TRNG_FEATURES_BITS					       \
    100 	"\177\020"	/* New bitmask */				       \
    101 	"f\003\01mode reset state\0"		/* bit  3 (1) */	       \
    102 	    "=\x0" "test mode\0"					       \
    103 	    "=\x1" "mission mode\0"					       \
    104 	"f\002\01ring oscillator\0"		/* bit  2 (1) */	       \
    105 	    "=\x0" "not preset\0"					       \
    106 	    "=\x1" "present\0"						       \
    107 	"f\000\02max rand length\0"		/* bits 0 .. 1 */	       \
    108 	    "=\x0" "128-bit\0"						       \
    109 	    "=\x1" "256-bit\0"						       \
    110 	"\0"
    111 
    112 
    113 #define JH7110_TRNG_DATA0		0x0020
    114 #define JH7110_TRNG_DATA1		0x0024
    115 #define JH7110_TRNG_DATA2		0x0028
    116 #define JH7110_TRNG_DATA3		0x002c
    117 #define JH7110_TRNG_DATA4		0x0030
    118 #define JH7110_TRNG_DATA5		0x0034
    119 #define JH7110_TRNG_DATA6		0x0038
    120 #define JH7110_TRNG_DATA7		0x003c
    121 
    122 #define JH7110_TRNG_BCONF		0x0068
    123 #define  JH7110_TRNG_BCONF_AUTO_RESEED_LOOPBACK	__BIT(5)
    124 #define  JH7110_TRNG_BCONF_MODE_AFTER_RST	__BIT(4)
    125 #define  JH7110_TRNG_BCONF_PRNG_LEN_AFTER_RST	__BIT(3)
    126 #define  JH7110_TRNG_BCONF_MAX_PRNG_LEN		__BIT(2)
    127 #define  JH7110_TRNG_BCONF_BITS						       \
    128 	"\177\020"	/* New bitmask */				       \
    129 	"f\005\01auto reseed loopback\0"	/* bit  5 (1) */	       \
    130 	    "=\x0" "not present\0"					       \
    131 	    "=\x1" "present\0"						       \
    132 	"f\004\01mode after reset\0"		/* bit  4 (1) */	       \
    133 	    "=\x0" "test mode\0"					       \
    134 	    "=\x1" "mission mode\0"					       \
    135 	"f\003\01PRNG after reset\0"		/* bit  3 (1) */	       \
    136 	    "=\x0" "not preset\0"					       \
    137 	    "=\x1" "present\0"						       \
    138 	"f\002\01max PRNG length\0"		/* bit  2 (1) */	       \
    139 	    "=\x0" "128-bit\0"						       \
    140 	    "=\x1" "256-bit\0"						       \
    141 	"\0"
    142 
    143 
    144 #define RD4(sc, reg)							       \
    145 	bus_space_read_4((sc)->sc_bst, (sc)->sc_bsh, (reg))
    146 #define WR4(sc, reg, val)						       \
    147 	bus_space_write_4((sc)->sc_bst, (sc)->sc_bsh, (reg), (val))
    148 
    149 
    150 static void
    151 jh7110_trng_irqenable(struct jh7110_trng_softc *sc)
    152 {
    153 	WR4(sc, JH7110_TRNG_IENABLE,
    154 	    JH7110_TRNG_IENABLE_GLOBAL |
    155 	    JH7110_TRNG_IENABLE_SEED_DONE |
    156 	    JH7110_TRNG_IENABLE_RAND_RDY |
    157 	    JH7110_TRNG_IENABLE_LFSR_LOCKUP);
    158 }
    159 
    160 static void
    161 jh7110_trng_irqdisable(struct jh7110_trng_softc *sc)
    162 {
    163 	WR4(sc, JH7110_TRNG_IENABLE, 0);
    164 }
    165 
    166 static void
    167 jh7110_trng_probe(struct jh7110_trng_softc *sc, uint32_t istat)
    168 {
    169 	KASSERT(mutex_owned(&sc->sc_lock));
    170 
    171 	if (sc->sc_bytes_wanted != 0) {
    172 		uint32_t data[8];
    173 		const uint32_t stat = RD4(sc, JH7110_TRNG_STAT);
    174 
    175 		if (stat & JH7110_TRNG_STAT_SEEDED) {
    176 			if (istat & JH7110_TRNG_ISTATUS_RAND_RDY) {
    177 
    178 				WR4(sc, JH7110_TRNG_ISTATUS,
    179 				    JH7110_TRNG_ISTATUS_RAND_RDY);
    180 
    181 				data[0] = RD4(sc, JH7110_TRNG_DATA0);
    182 				data[1] = RD4(sc, JH7110_TRNG_DATA1);
    183 				data[2] = RD4(sc, JH7110_TRNG_DATA2);
    184 				data[3] = RD4(sc, JH7110_TRNG_DATA3);
    185 				data[4] = RD4(sc, JH7110_TRNG_DATA4);
    186 				data[5] = RD4(sc, JH7110_TRNG_DATA5);
    187 				data[6] = RD4(sc, JH7110_TRNG_DATA6);
    188 				data[7] = RD4(sc, JH7110_TRNG_DATA7);
    189 
    190 				rnd_add_data_sync(&sc->sc_rndsource, &data,
    191 				    sizeof(data), sizeof(data) * NBBY);
    192 
    193 				sc->sc_bytes_wanted -=
    194 				    MIN(sc->sc_bytes_wanted, sizeof(data));
    195 
    196 				if (sc->sc_bytes_wanted == 0)
    197 					jh7110_trng_irqdisable(sc);
    198 			}
    199 		} else {
    200 			WR4(sc, JH7110_TRNG_CTRL,
    201 			    JH7110_TRNG_CTRL_RANDOM_RESEED);
    202 		}
    203 		explicit_memset(data, 0, sizeof data);
    204 	}
    205 	if (sc->sc_bytes_wanted != 0) {
    206 		WR4(sc, JH7110_TRNG_CTRL,
    207 		    JH7110_TRNG_CTRL_RANDOMIZE);
    208 	}
    209 }
    210 
    211 static void
    212 jh7110_trng_get(size_t bytes_wanted, void *arg)
    213 {
    214 	struct jh7110_trng_softc * const sc = arg;
    215 
    216 	mutex_enter(&sc->sc_lock);
    217 	sc->sc_bytes_wanted += bytes_wanted;
    218 
    219 	jh7110_trng_irqenable(sc);
    220 
    221 	const uint32_t istat = RD4(sc, JH7110_TRNG_ISTATUS);
    222 	jh7110_trng_probe(sc, istat);
    223 
    224 	mutex_exit(&sc->sc_lock);
    225 }
    226 
    227 
    228 static int
    229 jh7110_trng_intr(void *priv)
    230 {
    231 	struct jh7110_trng_softc * const sc = priv;
    232 
    233 	mutex_enter(&sc->sc_lock);
    234 
    235 	const uint32_t istat = RD4(sc, JH7110_TRNG_ISTATUS);
    236 
    237 	if (istat & JH7110_TRNG_ISTATUS_RAND_RDY) {
    238 		KASSERT(RD4(sc, JH7110_TRNG_STAT) & JH7110_TRNG_STAT_SEEDED);
    239 		jh7110_trng_probe(sc, istat);
    240 		//sc->sc_randready = true;
    241 
    242 	}
    243 
    244 	if (istat & JH7110_TRNG_ISTATUS_SEED_DONE)
    245 		sc->sc_reseeddone = true;
    246 
    247 #if 0
    248 	if (istat & JH7110_TRNG_ISTATUS_LFSR_LOCKUP) {
    249 		sc->sc_reseeddone = false;
    250 	}
    251 #endif
    252 	WR4(sc, JH7110_TRNG_ISTATUS, istat);
    253 
    254 	if (sc->sc_reseeddone)
    255 		cv_broadcast(&sc->sc_cv);
    256 
    257 	mutex_exit(&sc->sc_lock);
    258 
    259 	return 1;
    260 }
    261 
    262 
    263 static void
    264 jh7110_trng_init(struct jh7110_trng_softc *sc)
    265 {
    266 	/* Mask and clear all interrupts. */
    267 	WR4(sc, JH7110_TRNG_IENABLE,  0U);
    268 	WR4(sc, JH7110_TRNG_ISTATUS, ~0U);
    269 
    270 	WR4(sc, JH7110_TRNG_MODE, JH7110_TRNG_MODE_R256);
    271 
    272 	mutex_enter(&sc->sc_lock);
    273 
    274 	jh7110_trng_irqenable(sc);
    275 
    276 	sc->sc_reseeddone = false;
    277 	WR4(sc, JH7110_TRNG_CTRL, JH7110_TRNG_CTRL_RANDOM_RESEED);
    278 
    279 	while (!sc->sc_reseeddone) {
    280 		const int error = cv_timedwait(&sc->sc_cv, &sc->sc_lock, 1);
    281 		if (error) {
    282 			printf("%s: timedout\n", __func__);
    283 			mutex_exit(&sc->sc_lock);
    284 			return;
    285 		}
    286 	}
    287 	mutex_exit(&sc->sc_lock);
    288 }
    289 
    290 static void
    291 jh7110_trng_attach_i(device_t self)
    292 {
    293 	struct jh7110_trng_softc * const sc = device_private(self);
    294 
    295 	jh7110_trng_init(sc);
    296 
    297 	/* set up an rndsource */
    298 	rndsource_setcb(&sc->sc_rndsource, &jh7110_trng_get, sc);
    299 	rnd_attach_source(&sc->sc_rndsource, device_xname(self), RND_TYPE_RNG,
    300 	    RND_FLAG_COLLECT_VALUE | RND_FLAG_HASCB);
    301 }
    302 
    303 /* Compat string(s) */
    304 static const struct device_compatible_entry compat_data[] = {
    305 	{ .compat = "starfive,jh7110-trng" },
    306 	DEVICE_COMPAT_EOL
    307 };
    308 
    309 
    310 static int
    311 jh7110_trng_match(device_t parent, cfdata_t cf, void *aux)
    312 {
    313 	struct fdt_attach_args * const faa = aux;
    314 
    315 	return of_compatible_match(faa->faa_phandle, compat_data);
    316 }
    317 
    318 static void
    319 jh7110_trng_attach(device_t parent, device_t self, void *aux)
    320 {
    321 	struct jh7110_trng_softc * const sc = device_private(self);
    322 	struct fdt_attach_args * const faa = aux;
    323 	const int phandle = faa->faa_phandle;
    324 	bus_space_tag_t bst = faa->faa_bst;
    325 	bus_addr_t addr;
    326 	bus_size_t size;
    327 	int error;
    328 
    329 	if (fdtbus_get_reg(phandle, 0, &addr, &size) != 0) {
    330 		aprint_error(": couldn't get registers\n");
    331 		return;
    332 	}
    333 
    334 	error = bus_space_map(bst, addr, size, 0, &sc->sc_bsh);
    335 	if (error) {
    336 		aprint_error(": couldn't map %#" PRIxBUSADDR ": %d", addr,
    337 		    error);
    338 		return;
    339 	}
    340 
    341 	/* Enable the hclk clock.  */
    342 	error = fdtbus_clock_enable(phandle, "hclk", true);
    343 	if (error) {
    344 		aprint_error(": couldn't enable 'hclk' clock\n");
    345 		return;
    346 	}
    347 
    348 	/* Enable the hclk clock.  */
    349 	error = fdtbus_clock_enable(phandle, "ahb", true);
    350 	if (error) {
    351 		aprint_error(": couldn't enable 'ahb' clock\n");
    352 		return;
    353 	}
    354 
    355 	/* Get a reset handle if we need and try to deassert it.  */
    356 	struct fdtbus_reset * const rst = fdtbus_reset_get_index(phandle, 0);
    357 	if (rst != NULL) {
    358 		if (fdtbus_reset_deassert(rst) != 0) {
    359 			aprint_error(": couldn't de-assert reset\n");
    360 			return;
    361 		}
    362 	}
    363 
    364 	sc->sc_dev = self;
    365 	sc->sc_phandle = phandle;
    366 	sc->sc_bst = bst;
    367 
    368 	mutex_init(&sc->sc_lock, MUTEX_DEFAULT, IPL_VM);
    369 	cv_init(&sc->sc_cv, "jh7110trng");
    370 
    371 	aprint_naive("\n");
    372 	aprint_normal(": JH7110 TRNG\n");
    373 
    374 	char buf[256];
    375 
    376 	snprintb(buf, sizeof(buf), JH7110_TRNG_FEATURES_BITS,
    377 	    RD4(sc, JH7110_TRNG_FEATURES));
    378 	aprint_verbose_dev(sc->sc_dev, "Features    : %s\n", buf);
    379 
    380 	snprintb(buf, sizeof(buf), JH7110_TRNG_BCONF_BITS,
    381 	    RD4(sc, JH7110_TRNG_BCONF));
    382 	aprint_verbose_dev(sc->sc_dev, "Build config: %s\n", buf);
    383 
    384 	char intrstr[128];
    385 	if (!fdtbus_intr_str(phandle, 0, intrstr, sizeof(intrstr))) {
    386 		aprint_error_dev(self, "failed to decode interrupt\n");
    387 		return;
    388 	}
    389 
    390 	sc->sc_ih = fdtbus_intr_establish_xname(phandle, 0, IPL_VM,
    391 	    FDT_INTR_MPSAFE, jh7110_trng_intr, sc, device_xname(self));
    392 	if (sc->sc_ih == NULL) {
    393 		aprint_error_dev(self, "failed to establish interrupt on %s\n",
    394 		    intrstr);
    395 		return;
    396 	}
    397 	aprint_normal_dev(self, "interrupting on %s\n", intrstr);
    398 
    399 	config_interrupts(self, jh7110_trng_attach_i);
    400 }
    401 
    402 CFATTACH_DECL_NEW(jh7110_trng, sizeof(struct jh7110_trng_softc),
    403 	jh7110_trng_match, jh7110_trng_attach, NULL, NULL);
    404