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rk_spi.c revision 1.6.4.2
      1 /*	$NetBSD: rk_spi.c,v 1.6.4.2 2021/06/17 04:46:18 thorpej Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 2019 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Tobias Nygren.
      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: rk_spi.c,v 1.6.4.2 2021/06/17 04:46:18 thorpej Exp $");
     34 
     35 #include <sys/param.h>
     36 #include <sys/device.h>
     37 #include <sys/systm.h>
     38 #include <sys/bus.h>
     39 #include <sys/intr.h>
     40 #include <sys/kernel.h>
     41 #include <sys/bitops.h>
     42 #include <dev/spi/spivar.h>
     43 #include <dev/fdt/fdtvar.h>
     44 #include <arm/fdt/arm_fdtvar.h>
     45 
     46 #define SPI_CTRLR0		0x00
     47 #define SPI_CTRLR0_MTM		__BIT(21)
     48 #define SPI_CTRLR0_OPM		__BIT(20)
     49 #define SPI_CTRLR0_XFM		__BITS(19, 18)
     50 #define SPI_CTRLR0_FRF		__BITS(17, 16)
     51 #define SPI_CTRLR0_RSD		__BITS(15, 14)
     52 #define SPI_CTRLR0_BHT		__BIT(13)
     53 #define SPI_CTRLR0_FBM		__BIT(12)
     54 #define SPI_CTRLR0_EM		__BIT(11)
     55 #define SPI_CTRLR0_RW		__BIT(10)
     56 #define SPI_CTRLR0_CSM		__BITS(9, 8)
     57 #define SPI_CTRLR0_SCPOL	__BIT(7)
     58 #define SPI_CTRLR0_SCPH		__BIT(6)
     59 #define SPI_CTRLR0_CFS		__BITS(5, 2)
     60 #define SPI_CTRLR0_DFS		__BITS(1, 0)
     61 #define SPI_CTRLR0_DFS_4BIT	0x0
     62 #define SPI_CTRLR0_DFS_8BIT	0x1
     63 #define SPI_CTRLR0_DFS_16BIT	0x2
     64 
     65 #define SPI_CTRLR1		0x04
     66 #define SPI_CTRLR1_NDM		__BITS(15, 0)
     67 
     68 #define SPI_ENR			0x08
     69 #define SPI_ENR_ENR		__BIT(0)
     70 
     71 #define SPI_SER			0x0c
     72 #define SPI_SER_SER1		__BIT(1)
     73 #define SPI_SER_SER0		__BIT(0)
     74 
     75 #define SPI_BAUDR		0x10
     76 #define SPI_BAUDR_BAUDR		__BITS(15, 0)
     77 
     78 #define SPI_TXFTLR		0x14
     79 #define SPI_TXFTLR_TXFLTR	__BITS(4, 0)
     80 
     81 #define SPI_RXFTLR		0x18
     82 #define SPI_RXFLTR_RXFLTR	__BITS(4, 0)
     83 
     84 #define SPI_TXFLR		0x1c
     85 #define SPI_TXFLR_TXFLR		__BITS(5, 0)
     86 
     87 #define SPI_RXFLR		0x20
     88 #define SPI_RXFLR_RXFLR		__BITS(5, 0)
     89 
     90 #define SPI_SR			0x24
     91 #define SPI_SR_RFF		__BIT(4)
     92 #define SPI_SR_RFE		__BIT(3)
     93 #define SPI_SR_TFE		__BIT(2)
     94 #define SPI_SR_TFF		__BIT(1)
     95 #define SPI_SR_BSF		__BIT(0)
     96 
     97 #define SPI_IPR			0x28
     98 #define SPI_IPR_IPR		__BIT(0)
     99 
    100 #define SPI_IMR			0x2c
    101 #define SPI_IMR_RFFIM		__BIT(4)
    102 #define SPI_IMR_RFOIM		__BIT(3)
    103 #define SPI_IMR_RFUIM		__BIT(2)
    104 #define SPI_IMR_TFOIM		__BIT(1)
    105 #define SPI_IMR_TFEIM		__BIT(0)
    106 
    107 #define SPI_ISR			0x30
    108 #define SPI_ISR_RFFIS		__BIT(4)
    109 #define SPI_ISR_RFOIS		__BIT(3)
    110 #define SPI_ISR_RFUIS		__BIT(2)
    111 #define SPI_ISR_TFOIS		__BIT(1)
    112 #define SPI_ISR_TFEIS		__BIT(0)
    113 
    114 #define SPI_RISR		0x34
    115 #define SPI_RISR_RFFRIS		__BIT(4)
    116 #define SPI_RISR_RFORIS		__BIT(3)
    117 #define SPI_RISR_RFURIS		__BIT(2)
    118 #define SPI_RISR_TFORIS		__BIT(1)
    119 #define SPI_RISR_TFERIS		__BIT(0)
    120 
    121 #define SPI_ICR			0x38
    122 #define SPI_ICR_CTFOI		__BIT(3)
    123 #define SPI_ICR_CRFOI		__BIT(2)
    124 #define SPI_ICR_CRFUI		__BIT(1)
    125 #define SPI_ICR_CCI		__BIT(0)
    126 #define SPI_ICR_ALL		__BITS(3, 0)
    127 
    128 #define SPI_DMACR		0x3c
    129 #define SPI_DMACR_TDE		__BIT(1)
    130 #define SPI_DMACR_RDE		__BIT(0)
    131 
    132 #define SPI_DMATDLR		0x40
    133 #define SPI_DMATDLR_TDL		__BITS(4, 0)
    134 
    135 #define SPI_DMARDLR		0x44
    136 #define SPI_DMARDLR_RDL		__BITS(4, 0)
    137 
    138 #define SPI_TXDR		0x400
    139 #define SPI_TXDR_TXDR		__BITS(15, 0)
    140 
    141 #define SPI_RXDR		0x800
    142 #define SPI_RXDR_RXDR		__BITS(15, 0)
    143 
    144 #define SPI_FIFOLEN		32
    145 
    146 static const struct device_compatible_entry compat_data[] = {
    147 	{ .compat = "rockchip,rk3066-spi" },
    148 	{ .compat = "rockchip,rk3328-spi" },
    149 	{ .compat = "rockchip,rk3399-spi" },
    150 	DEVICE_COMPAT_EOL
    151 };
    152 
    153 struct rk_spi_softc {
    154 	device_t		sc_dev;
    155 	bus_space_tag_t		sc_bst;
    156 	bus_space_handle_t	sc_bsh;
    157 	void			*sc_ih;
    158 	u_int			sc_spi_freq;
    159 	struct spi_controller	sc_spi;
    160 	SIMPLEQ_HEAD(,spi_transfer) sc_q;
    161 	struct spi_transfer	*sc_transfer;
    162 	struct spi_chunk	*sc_rchunk, *sc_wchunk;
    163 	volatile bool		sc_running;
    164 };
    165 
    166 #define SPIREG_READ(sc, reg) \
    167     bus_space_read_4((sc)->sc_bst, (sc)->sc_bsh, (reg))
    168 #define SPIREG_WRITE(sc, reg, val) \
    169     bus_space_write_4((sc)->sc_bst, (sc)->sc_bsh, (reg), (val))
    170 
    171 static int rk_spi_match(device_t, cfdata_t, void *);
    172 static void rk_spi_attach(device_t, device_t, void *);
    173 
    174 static int rk_spi_configure(void *, int, int, int);
    175 static int rk_spi_transfer(void *, struct spi_transfer *);
    176 
    177 static void rk_spi_txfifo_fill(struct rk_spi_softc * const, size_t);
    178 static void rk_spi_rxfifo_drain(struct rk_spi_softc * const, size_t);
    179 static void rk_spi_rxtx(struct rk_spi_softc * const);
    180 static void rk_spi_set_interrupt_mask(struct rk_spi_softc * const);
    181 static void rk_spi_start(struct rk_spi_softc * const);
    182 static int rk_spi_intr(void *);
    183 
    184 CFATTACH_DECL_NEW(rk_spi, sizeof(struct rk_spi_softc),
    185     rk_spi_match, rk_spi_attach, NULL, NULL);
    186 
    187 static int
    188 rk_spi_match(device_t parent, cfdata_t cf, void *aux)
    189 {
    190 	struct fdt_attach_args * const faa = aux;
    191 
    192 	return of_compatible_match(faa->faa_phandle, compat_data);
    193 }
    194 
    195 static void
    196 rk_spi_attach(device_t parent, device_t self, void *aux)
    197 {
    198 	struct rk_spi_softc * const sc = device_private(self);
    199 	struct fdt_attach_args * const faa = aux;
    200 	const int phandle = faa->faa_phandle;
    201 	bus_addr_t addr;
    202 	bus_size_t size;
    203 	struct clk *sclk, *pclk;
    204 	char intrstr[128];
    205 
    206 	sc->sc_dev = self;
    207 	sc->sc_bst = faa->faa_bst;
    208 	SIMPLEQ_INIT(&sc->sc_q);
    209 
    210 	if ((sclk = fdtbus_clock_get(phandle, "spiclk")) == NULL
    211 	    || clk_enable(sclk) != 0) {
    212 		aprint_error(": couldn't enable sclk\n");
    213 		return;
    214 	}
    215 
    216 	if ((pclk = fdtbus_clock_get(phandle, "apb_pclk")) == NULL
    217 	    || clk_enable(pclk) != 0) {
    218 		aprint_error(": couldn't enable pclk\n");
    219 		return;
    220 	}
    221 
    222 	sc->sc_spi_freq = clk_get_rate(sclk);
    223 
    224 	if (fdtbus_get_reg(phandle, 0, &addr, &size) != 0
    225 	    || bus_space_map(sc->sc_bst, addr, size, 0, &sc->sc_bsh) != 0) {
    226 		aprint_error(": couldn't map registers\n");
    227 		return;
    228 	}
    229 
    230 	SPIREG_WRITE(sc, SPI_ENR, 0);
    231 	SPIREG_WRITE(sc, SPI_IMR, 0);
    232 
    233 	if (!fdtbus_intr_str(phandle, 0, intrstr, sizeof(intrstr))) {
    234 		aprint_error(": failed to decode interrupt\n");
    235 		return;
    236 	}
    237 
    238 	sc->sc_ih = fdtbus_intr_establish_xname(phandle, 0, IPL_VM, 0,
    239 	    rk_spi_intr, sc, device_xname(self));
    240 	if (sc->sc_ih == NULL) {
    241 		aprint_error(": unable to establish interrupt\n");
    242 		return;
    243 	}
    244 
    245 	aprint_naive("\n");
    246 	aprint_normal(": SPI\n");
    247 	aprint_normal_dev(self, "interrupting on %s\n", intrstr);
    248 
    249 	sc->sc_spi.sct_cookie = sc;
    250 	sc->sc_spi.sct_configure = rk_spi_configure;
    251 	sc->sc_spi.sct_transfer = rk_spi_transfer;
    252 	sc->sc_spi.sct_nslaves = 2;
    253 
    254 	fdtbus_register_spi_controller(&sc->sc_spi, phandle);
    255 
    256 	struct spibus_attach_args sba = {
    257 		.sba_controller = &sc->sc_spi,
    258 	};
    259 	config_found(self, &sba, spibus_print,
    260 	    CFARG_DEVHANDLE, device_handle(self),
    261 	    CFARG_EOL);
    262 }
    263 
    264 static int
    265 rk_spi_configure(void *cookie, int slave, int mode, int speed)
    266 {
    267 	struct rk_spi_softc * const sc = cookie;
    268 	uint32_t ctrlr0;
    269 	uint16_t divider;
    270 
    271 	divider = (sc->sc_spi_freq / speed) & ~1;
    272 	if (divider < 2) {
    273 		aprint_error_dev(sc->sc_dev,
    274 		    "spi_clk %u is too low for speed %u, using speed %u\n",
    275 		     sc->sc_spi_freq, speed, sc->sc_spi_freq / 2);
    276 		divider = 2;
    277 	}
    278 
    279 	if (slave >= sc->sc_spi.sct_nslaves)
    280 		return EINVAL;
    281 
    282 	ctrlr0 = SPI_CTRLR0_BHT | __SHIFTIN(SPI_CTRLR0_DFS_8BIT, SPI_CTRLR0_DFS);
    283 
    284 	switch (mode) {
    285 	case SPI_MODE_0:
    286 		ctrlr0 |= 0;
    287 		break;
    288 	case SPI_MODE_1:
    289 		ctrlr0 |= SPI_CTRLR0_SCPH;
    290 		break;
    291 	case SPI_MODE_2:
    292 		ctrlr0 |= SPI_CTRLR0_SCPOL;
    293 		break;
    294 	case SPI_MODE_3:
    295 		ctrlr0 |= SPI_CTRLR0_SCPH | SPI_CTRLR0_SCPOL;
    296 		break;
    297 	default:
    298 		return EINVAL;
    299 	}
    300 
    301 	SPIREG_WRITE(sc, SPI_ENR, 0);
    302 	SPIREG_WRITE(sc, SPI_SER, 0);
    303 	SPIREG_WRITE(sc, SPI_CTRLR0, ctrlr0);
    304 	SPIREG_WRITE(sc, SPI_BAUDR, divider);
    305 
    306 	SPIREG_WRITE(sc, SPI_DMACR, 0);
    307 	SPIREG_WRITE(sc, SPI_DMATDLR, 0);
    308 	SPIREG_WRITE(sc, SPI_DMARDLR, 0);
    309 
    310 	SPIREG_WRITE(sc, SPI_IPR, 0);
    311 	SPIREG_WRITE(sc, SPI_IMR, 0);
    312 	SPIREG_WRITE(sc, SPI_ICR, SPI_ICR_ALL);
    313 
    314 	SPIREG_WRITE(sc, SPI_ENR, 1);
    315 
    316 	return 0;
    317 }
    318 
    319 static int
    320 rk_spi_transfer(void *cookie, struct spi_transfer *st)
    321 {
    322 	struct rk_spi_softc * const sc = cookie;
    323 	int s;
    324 
    325 	s = splbio();
    326 	spi_transq_enqueue(&sc->sc_q, st);
    327 	if (sc->sc_running == false) {
    328 		rk_spi_start(sc);
    329 	}
    330 	splx(s);
    331 
    332 	return 0;
    333 }
    334 
    335 static void
    336 rk_spi_txfifo_fill(struct rk_spi_softc * const sc, size_t maxlen)
    337 {
    338 	struct spi_chunk *chunk = sc->sc_wchunk;
    339 	size_t len;
    340 	uint8_t b;
    341 
    342 	if (chunk == NULL)
    343 		return;
    344 
    345 	len = MIN(maxlen, chunk->chunk_wresid);
    346 	chunk->chunk_wresid -= len;
    347 	while (len--) {
    348 		if (chunk->chunk_wptr) {
    349 			b = *chunk->chunk_wptr++;
    350 		} else {
    351 			b = 0;
    352 		}
    353 		bus_space_write_1(sc->sc_bst, sc->sc_bsh, SPI_TXDR, b);
    354 	}
    355 	if (sc->sc_wchunk->chunk_wresid == 0) {
    356 		sc->sc_wchunk = sc->sc_wchunk->chunk_next;
    357 	}
    358 }
    359 
    360 static void
    361 rk_spi_rxfifo_drain(struct rk_spi_softc * const sc, size_t maxlen)
    362 {
    363 	struct spi_chunk *chunk = sc->sc_rchunk;
    364 	size_t len;
    365 	uint8_t b;
    366 
    367 	if (chunk == NULL)
    368 		return;
    369 
    370 	len = MIN(maxlen, chunk->chunk_rresid);
    371 	chunk->chunk_rresid -= len;
    372 
    373 	while (len--) {
    374 		b = bus_space_read_1(sc->sc_bst, sc->sc_bsh, SPI_RXDR);
    375 		if (chunk->chunk_rptr) {
    376 			*chunk->chunk_rptr++ = b;
    377 		}
    378 	}
    379 	if (sc->sc_rchunk->chunk_rresid == 0) {
    380 		sc->sc_rchunk = sc->sc_rchunk->chunk_next;
    381 	}
    382 }
    383 
    384 static void
    385 rk_spi_rxtx(struct rk_spi_softc * const sc)
    386 {
    387 	bool again;
    388 	uint32_t reg;
    389 	size_t avail;
    390 
    391 	/* Service both FIFOs until no more progress can be made. */
    392 	again = true;
    393 	while (again) {
    394 		again = false;
    395 		reg = SPIREG_READ(sc, SPI_RXFLR);
    396 		avail = __SHIFTOUT(reg, SPI_RXFLR_RXFLR);
    397 		if (avail > 0) {
    398 			KASSERT(sc->sc_rchunk != NULL);
    399 			rk_spi_rxfifo_drain(sc, avail);
    400 			again = true;
    401 		}
    402 		reg = SPIREG_READ(sc, SPI_TXFLR);
    403 		avail = SPI_FIFOLEN - __SHIFTOUT(reg, SPI_TXFLR_TXFLR);
    404 		if (avail > 0 && sc->sc_wchunk != NULL) {
    405 			rk_spi_txfifo_fill(sc, avail);
    406 			again = true;
    407 		}
    408 	}
    409 }
    410 
    411 static void
    412 rk_spi_set_interrupt_mask(struct rk_spi_softc * const sc)
    413 {
    414 	uint32_t imr = SPI_IMR_RFOIM | SPI_IMR_RFUIM | SPI_IMR_TFOIM;
    415 	int len;
    416 
    417 	/*
    418 	 * Delay rx interrupts until the FIFO has the # of bytes we'd
    419 	 * ideally like to receive, or FIFO is half full.
    420 	 */
    421 	len = sc->sc_rchunk != NULL
    422 	    ? MIN(sc->sc_rchunk->chunk_rresid, SPI_FIFOLEN / 2) : 0;
    423 	if (len > 0) {
    424 		SPIREG_WRITE(sc, SPI_RXFTLR, len - 1);
    425 		imr |= SPI_IMR_RFFIM;
    426 	}
    427 
    428 	/*
    429 	 * Delay tx interrupts until the FIFO can accept the # of bytes we'd
    430 	 * ideally like to transmit, or the FIFO is half empty.
    431 	 */
    432 	len = sc->sc_wchunk != NULL
    433 	    ? MIN(sc->sc_wchunk->chunk_wresid, SPI_FIFOLEN / 2) : 0;
    434 	if (len > 0) {
    435 		SPIREG_WRITE(sc, SPI_TXFTLR, SPI_FIFOLEN - len);
    436 		imr |= SPI_IMR_TFEIM;
    437 	}
    438 
    439 	/* If xfer is done, then interrupt as soon as the tx fifo is empty. */
    440 	if (!ISSET(imr, (SPI_IMR_RFFIM | SPI_IMR_TFEIM))) {
    441 		SPIREG_WRITE(sc, SPI_TXFTLR, 0);
    442 		imr |= SPI_IMR_TFEIM;
    443 	}
    444 
    445 	SPIREG_WRITE(sc, SPI_IMR, imr);
    446 }
    447 
    448 static void
    449 rk_spi_start(struct rk_spi_softc * const sc)
    450 {
    451 	struct spi_transfer *st;
    452 
    453 	while ((st = spi_transq_first(&sc->sc_q)) != NULL) {
    454 		spi_transq_dequeue(&sc->sc_q);
    455 		KASSERT(sc->sc_transfer == NULL);
    456 		sc->sc_transfer = st;
    457 		sc->sc_rchunk = sc->sc_wchunk = st->st_chunks;
    458 		sc->sc_running = true;
    459 
    460 		KASSERT(st->st_slave < sc->sc_spi.sct_nslaves);
    461 		SPIREG_WRITE(sc, SPI_SER, 1 << st->st_slave);
    462 
    463 		rk_spi_rxtx(sc);
    464 		rk_spi_set_interrupt_mask(sc);
    465 
    466 		if (!cold)
    467 			return;
    468 
    469 		for (;;) {
    470 			(void) rk_spi_intr(sc);
    471 			if (ISSET(st->st_flags, SPI_F_DONE))
    472 				break;
    473 		}
    474 	}
    475 	sc->sc_running = false;
    476 }
    477 
    478 static int
    479 rk_spi_intr(void *cookie)
    480 {
    481 	struct rk_spi_softc * const sc = cookie;
    482 	struct spi_transfer *st;
    483 	uint32_t isr;
    484 	uint32_t sr;
    485 	uint32_t icr = SPI_ICR_CCI;
    486 
    487 	isr = SPIREG_READ(sc, SPI_ISR);
    488 	if (!isr)
    489 		return 0;
    490 
    491 	if (ISSET(isr, SPI_ISR_RFOIS)) {
    492 		device_printf(sc->sc_dev, "RXFIFO overflow\n");
    493 		icr |= SPI_ICR_CRFOI;
    494 	}
    495 	if (ISSET(isr, SPI_ISR_RFUIS)) {
    496 		device_printf(sc->sc_dev, "RXFIFO underflow\n");
    497 		icr |= SPI_ICR_CRFUI;
    498 	}
    499 	if (ISSET(isr, SPI_ISR_TFOIS)) {
    500 		device_printf(sc->sc_dev, "TXFIFO overflow\n");
    501 		icr |= SPI_ICR_CTFOI;
    502 	}
    503 
    504 	rk_spi_rxtx(sc);
    505 
    506 	if (sc->sc_rchunk == NULL && sc->sc_wchunk == NULL) {
    507 		do {
    508 			sr = SPIREG_READ(sc, SPI_SR);
    509 		} while (ISSET(sr, SPI_SR_BSF));
    510 		SPIREG_WRITE(sc, SPI_IMR, 0);
    511 		SPIREG_WRITE(sc, SPI_SER, 0);
    512 		st = sc->sc_transfer;
    513 		sc->sc_transfer = NULL;
    514 		KASSERT(st != NULL);
    515 		spi_done(st, 0);
    516 		sc->sc_running = false;
    517 	} else {
    518 		rk_spi_set_interrupt_mask(sc);
    519 	}
    520 
    521 	SPIREG_WRITE(sc, SPI_ICR, icr);
    522 
    523 	return 1;
    524 }
    525