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imxspi.c revision 1.2.12.1
      1 /*	$NetBSD: imxspi.c,v 1.2.12.1 2017/08/28 17:51:30 skrll Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2014  Genetec Corporation.  All rights reserved.
      5  * Written by Hashimoto Kenichi for Genetec Corporation.
      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 GENETEC CORPORATION ``AS IS'' AND
     17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     18  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     19  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL GENETEC CORPORATION
     20  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     21  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     22  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     23  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     24  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     25  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     26  * POSSIBILITY OF SUCH DAMAGE.
     27  */
     28 
     29 /*
     30  * this module support CSPI and eCSPI.
     31  * i.MX51 have 2 eCSPI and 1 CSPI modules.
     32  */
     33 
     34 #include <sys/cdefs.h>
     35 __KERNEL_RCSID(0, "$NetBSD: imxspi.c,v 1.2.12.1 2017/08/28 17:51:30 skrll Exp $");
     36 
     37 #include "opt_imx.h"
     38 #include "opt_imxspi.h"
     39 
     40 #include <sys/param.h>
     41 #include <sys/systm.h>
     42 #include <sys/kernel.h>
     43 #include <sys/device.h>
     44 #include <sys/errno.h>
     45 #include <sys/proc.h>
     46 #include <sys/intr.h>
     47 
     48 #include <sys/bus.h>
     49 #include <machine/cpu.h>
     50 #include <machine/intr.h>
     51 
     52 #include <arm/imx/imxspivar.h>
     53 #include <arm/imx/imxspireg.h>
     54 
     55 /* SPI service routines */
     56 static int imxspi_configure_enhanced(void *, int, int, int);
     57 static int imxspi_configure(void *, int, int, int);
     58 static int imxspi_transfer(void *, struct spi_transfer *);
     59 static int imxspi_intr(void *);
     60 
     61 /* internal stuff */
     62 void imxspi_done(struct imxspi_softc *, int);
     63 void imxspi_send(struct imxspi_softc *);
     64 void imxspi_recv(struct imxspi_softc *);
     65 void imxspi_sched(struct imxspi_softc *);
     66 
     67 #define	IMXSPI(x)							      \
     68 	((sc->sc_enhanced) ? __CONCAT(ECSPI_, x) : __CONCAT(CSPI_, x))
     69 #define	READ_REG(sc, x)							      \
     70 	bus_space_read_4(sc->sc_iot, sc->sc_ioh, IMXSPI(x))
     71 #define	WRITE_REG(sc, x, v)						      \
     72 	bus_space_write_4(sc->sc_iot, sc->sc_ioh, IMXSPI(x), (v))
     73 
     74 #ifdef IMXSPI_DEBUG
     75 int imxspi_debug = IMXSPI_DEBUG;
     76 #define	DPRINTFN(n,x)   if (imxspi_debug>(n)) printf x;
     77 #else
     78 #define	DPRINTFN(n,x)
     79 #endif
     80 
     81 int
     82 imxspi_attach_common(device_t parent, struct imxspi_softc *sc, void *aux)
     83 {
     84 	struct imxspi_attach_args *saa = aux;
     85 	struct spibus_attach_args sba;
     86 	bus_addr_t addr = saa->saa_addr;
     87 	bus_size_t size = saa->saa_size;
     88 
     89 	sc->sc_iot = saa->saa_iot;
     90 	sc->sc_freq = saa->saa_freq;
     91 	sc->sc_tag = saa->saa_tag;
     92 	sc->sc_enhanced = saa->saa_enhanced;
     93 	if (size <= 0)
     94 		size = SPI_SIZE;
     95 
     96 	if (bus_space_map(sc->sc_iot, addr, size, 0, &sc->sc_ioh)) {
     97 		aprint_error_dev(sc->sc_dev, "couldn't map registers\n");
     98 		return 1;
     99 	}
    100 
    101 	aprint_normal(": i.MX %sCSPI Controller (clock %ld Hz)\n",
    102 	    ((sc->sc_enhanced) ? "e" : ""), sc->sc_freq);
    103 
    104 	/* Initialize SPI controller */
    105 	sc->sc_spi.sct_cookie = sc;
    106 	if (sc->sc_enhanced)
    107 		sc->sc_spi.sct_configure = imxspi_configure_enhanced;
    108 	else
    109 		sc->sc_spi.sct_configure = imxspi_configure;
    110 	sc->sc_spi.sct_transfer = imxspi_transfer;
    111 
    112 	/* sc->sc_spi.sct_nslaves must have been initialized by machdep code */
    113 	sc->sc_spi.sct_nslaves = saa->saa_nslaves;
    114 	if (!sc->sc_spi.sct_nslaves)
    115 		aprint_error_dev(sc->sc_dev, "no slaves!\n");
    116 
    117 	sba.sba_controller = &sc->sc_spi;
    118 
    119 	/* initialize the queue */
    120 	SIMPLEQ_INIT(&sc->sc_q);
    121 
    122 	/* configure SPI */
    123 	/* Setup Control Register */
    124 	WRITE_REG(sc, CONREG, __SHIFTIN(0, IMXSPI(CON_DRCTL)) |
    125 	    __SHIFTIN(8 - 1, IMXSPI(CON_BITCOUNT)) |
    126 	    __SHIFTIN(0xf, IMXSPI(CON_MODE)) | IMXSPI(CON_ENABLE));
    127 
    128 	/* TC and RR interruption */
    129 	WRITE_REG(sc, INTREG,  (IMXSPI(INTR_TC_EN) | IMXSPI(INTR_RR_EN)));
    130 	WRITE_REG(sc, STATREG, IMXSPI(STAT_CLR));
    131 
    132 	WRITE_REG(sc, PERIODREG, 0x0);
    133 
    134 	/* enable device interrupts */
    135 	sc->sc_ih = intr_establish(saa->saa_irq, IPL_BIO, IST_LEVEL,
    136 	    imxspi_intr, sc);
    137 
    138 	/* attach slave devices */
    139 	(void)config_found_ia(sc->sc_dev, "spibus", &sba, spibus_print);
    140 
    141 	return 0;
    142 }
    143 
    144 static int
    145 imxspi_configure(void *arg, int slave, int mode, int speed)
    146 {
    147 	struct imxspi_softc *sc = arg;
    148 	uint32_t div_cnt = 0;
    149 	uint32_t div;
    150 	uint32_t contrl = 0;
    151 
    152 	div = (sc->sc_freq + (speed - 1)) / speed;
    153 	div = div - 1;
    154 	for (div_cnt = 0; div > 0; div_cnt++)
    155 		div >>= 1;
    156 
    157 	div_cnt = div_cnt - 2;
    158 	if (div_cnt >= 7)
    159 		div_cnt = 7;
    160 
    161 	contrl = READ_REG(sc, CONREG);
    162 	contrl &= ~CSPI_CON_DIV;
    163 	contrl |= __SHIFTIN(div_cnt, CSPI_CON_DIV);
    164 
    165 	contrl &= ~(CSPI_CON_POL | CSPI_CON_PHA);
    166 	switch (mode) {
    167 	case SPI_MODE_0:
    168 		/* CPHA = 0, CPOL = 0 */
    169 		break;
    170 	case SPI_MODE_1:
    171 		/* CPHA = 1, CPOL = 0 */
    172 		contrl |= CSPI_CON_PHA;
    173 		break;
    174 	case SPI_MODE_2:
    175 		/* CPHA = 0, CPOL = 1 */
    176 		contrl |= CSPI_CON_POL;
    177 		break;
    178 	case SPI_MODE_3:
    179 		/* CPHA = 1, CPOL = 1 */
    180 		contrl |= CSPI_CON_POL;
    181 		contrl |= CSPI_CON_PHA;
    182 		break;
    183 	default:
    184 		return EINVAL;
    185 	}
    186 	WRITE_REG(sc, CONREG, contrl);
    187 
    188 	DPRINTFN(3, ("%s: slave %d mode %d speed %d\n",
    189 		__func__, slave, mode, speed));
    190 
    191 	return 0;
    192 }
    193 
    194 static int
    195 imxspi_configure_enhanced(void *arg, int slave, int mode, int speed)
    196 {
    197 	struct imxspi_softc *sc = arg;
    198 	uint32_t div_cnt = 0;
    199 	uint32_t div;
    200 	uint32_t contrl = 0;
    201 	uint32_t config = 0;
    202 
    203 	div = (sc->sc_freq + (speed - 1)) / speed;
    204 	for (div_cnt = 0; div > 0; div_cnt++)
    205 		div >>= 1;
    206 
    207 	if (div_cnt >= 15)
    208 		div_cnt = 15;
    209 
    210 	contrl = READ_REG(sc, CONREG);
    211 	contrl |= __SHIFTIN(div_cnt, ECSPI_CON_DIV);
    212 	contrl |= __SHIFTIN(slave, ECSPI_CON_CS);
    213 	contrl |= __SHIFTIN(__BIT(slave), ECSPI_CON_MODE);
    214 	WRITE_REG(sc, CONREG, contrl);
    215 
    216 	config = bus_space_read_4(sc->sc_iot, sc->sc_ioh, ECSPI_CONFIGREG);
    217 	config &= ~(__SHIFTIN(__BIT(slave), ECSPI_CONFIG_SCLK_POL) |
    218 	    __SHIFTIN(__BIT(slave), ECSPI_CONFIG_SCLK_PHA));
    219 	switch (mode) {
    220 	case SPI_MODE_0:
    221 		/* CPHA = 0, CPOL = 0 */
    222 		break;
    223 	case SPI_MODE_1:
    224 		/* CPHA = 1, CPOL = 0 */
    225 		config |= __SHIFTIN(__BIT(slave), ECSPI_CONFIG_SCLK_PHA);
    226 		break;
    227 	case SPI_MODE_2:
    228 		/* CPHA = 0, CPOL = 1 */
    229 		config |= __SHIFTIN(__BIT(slave), ECSPI_CONFIG_SCLK_POL);
    230 		break;
    231 	case SPI_MODE_3:
    232 		/* CPHA = 1, CPOL = 1 */
    233 		config |= __SHIFTIN(__BIT(slave), ECSPI_CONFIG_SCLK_PHA);
    234 		config |= __SHIFTIN(__BIT(slave), ECSPI_CONFIG_SCLK_POL);
    235 		break;
    236 	default:
    237 		return EINVAL;
    238 	}
    239 	config |= __SHIFTIN(__BIT(slave), ECSPI_CONFIG_SSB_CTL);
    240 	bus_space_write_4(sc->sc_iot, sc->sc_ioh, ECSPI_CONFIGREG, config);
    241 
    242 	DPRINTFN(3, ("%s: slave %d mode %d speed %d\n",
    243 		__func__, slave, mode, speed));
    244 
    245 	return 0;
    246 }
    247 
    248 void
    249 imxspi_send(struct imxspi_softc *sc)
    250 {
    251 	uint32_t data;
    252 	struct spi_chunk *chunk;
    253 
    254 	/* fill the fifo */
    255 	while ((chunk = sc->sc_wchunk) != NULL) {
    256 		while (chunk->chunk_wresid) {
    257 			/* transmit fifo full? */
    258 			if (READ_REG(sc, STATREG) & IMXSPI(STAT_TF))
    259 				goto out;
    260 
    261 			if (chunk->chunk_wptr) {
    262 				data = *chunk->chunk_wptr;
    263 				chunk->chunk_wptr++;
    264 			} else {
    265 				data = 0xff;
    266 			}
    267 			chunk->chunk_wresid--;
    268 
    269 			WRITE_REG(sc, TXDATA, data);
    270 		}
    271 		/* advance to next transfer */
    272 		sc->sc_wchunk = sc->sc_wchunk->chunk_next;
    273 	}
    274 out:
    275 	if (!(READ_REG(sc, STATREG) & IMXSPI(INTR_TE_EN)))
    276 		WRITE_REG(sc, CONREG, READ_REG(sc, CONREG) | IMXSPI(CON_XCH));
    277 }
    278 
    279 void
    280 imxspi_recv(struct imxspi_softc *sc)
    281 {
    282 	uint32_t		data;
    283 	struct spi_chunk	*chunk;
    284 
    285 	while ((chunk = sc->sc_rchunk) != NULL) {
    286 		while (chunk->chunk_rresid) {
    287 			/* rx fifo empty? */
    288 			if ((!(READ_REG(sc, STATREG) & IMXSPI(STAT_RR))))
    289 				return;
    290 
    291 			/* collect rx data */
    292 			data = READ_REG(sc, RXDATA);
    293 			if (chunk->chunk_rptr) {
    294 				*chunk->chunk_rptr = data & 0xff;
    295 				chunk->chunk_rptr++;
    296 			}
    297 
    298 			chunk->chunk_rresid--;
    299 		}
    300 		/* advance next to next transfer */
    301 		sc->sc_rchunk = sc->sc_rchunk->chunk_next;
    302 	}
    303 }
    304 
    305 
    306 void
    307 imxspi_sched(struct imxspi_softc *sc)
    308 {
    309 	struct spi_transfer *st;
    310 	uint32_t chipselect;
    311 
    312 	while ((st = spi_transq_first(&sc->sc_q)) != NULL) {
    313 		/* remove the item */
    314 		spi_transq_dequeue(&sc->sc_q);
    315 
    316 		/* note that we are working on it */
    317 		sc->sc_transfer = st;
    318 
    319 		/* chip slect */
    320 		if (sc->sc_tag->spi_cs_enable != NULL)
    321 			sc->sc_tag->spi_cs_enable(sc->sc_tag->cookie,
    322 			    st->st_slave);
    323 
    324 		/* chip slect */
    325 		chipselect = READ_REG(sc, CONREG);
    326 		chipselect &= ~IMXSPI(CON_CS);
    327 		chipselect |= __SHIFTIN(st->st_slave, IMXSPI(CON_CS));
    328 		WRITE_REG(sc, CONREG, chipselect);
    329 
    330 		delay(1);
    331 
    332 		/* setup chunks */
    333 		sc->sc_rchunk = sc->sc_wchunk = st->st_chunks;
    334 
    335 		/* now kick the master start to get the chip running */
    336 		imxspi_send(sc);
    337 
    338 		sc->sc_running = TRUE;
    339 		return;
    340 	}
    341 
    342 	DPRINTFN(2, ("%s: nothing to do anymore\n", __func__));
    343 	sc->sc_running = FALSE;
    344 }
    345 
    346 void
    347 imxspi_done(struct imxspi_softc *sc, int err)
    348 {
    349 	struct spi_transfer *st;
    350 
    351 	/* called from interrupt handler */
    352 	if ((st = sc->sc_transfer) != NULL) {
    353 		if (sc->sc_tag->spi_cs_disable != NULL)
    354 			sc->sc_tag->spi_cs_disable(sc->sc_tag->cookie,
    355 			    st->st_slave);
    356 
    357 		sc->sc_transfer = NULL;
    358 		spi_done(st, err);
    359 	}
    360 	/* make sure we clear these bits out */
    361 	sc->sc_wchunk = sc->sc_rchunk = NULL;
    362 	imxspi_sched(sc);
    363 }
    364 
    365 static int
    366 imxspi_intr(void *arg)
    367 {
    368 	struct imxspi_softc *sc = arg;
    369 	uint32_t intr, sr;
    370 	int err = 0;
    371 
    372 	if ((intr = READ_REG(sc, INTREG)) == 0) {
    373 		/* interrupts are not enabled, get out */
    374 		DPRINTFN(4, ("%s: interrupts are not enabled\n", __func__));
    375 		return 0;
    376 	}
    377 
    378 	sr = READ_REG(sc, STATREG);
    379 	if (!(sr & intr)) {
    380 		/* interrupt did not happen, get out */
    381 		DPRINTFN(3, ("%s: interrupts did not happen\n", __func__));
    382 		return 0;
    383 	}
    384 
    385 	/* RXFIFO ready? */
    386 	if (sr & IMXSPI(INTR_RR_EN)) {
    387 		imxspi_recv(sc);
    388 		if (sc->sc_wchunk == NULL && sc->sc_rchunk == NULL)
    389 			imxspi_done(sc, err);
    390 	}
    391 
    392 	/* Transfer Conplete? */
    393 	if (sr & IMXSPI(INTR_TC_EN)) {
    394 		/* complete TX */
    395 		imxspi_send(sc);
    396 	}
    397 
    398 	/* status register clear */
    399 	WRITE_REG(sc, STATREG, sr);
    400 
    401 	return 1;
    402 }
    403 
    404 int
    405 imxspi_transfer(void *arg, struct spi_transfer *st)
    406 {
    407 	struct imxspi_softc *sc = arg;
    408 	int s;
    409 
    410 	/* make sure we select the right chip */
    411 	s = splbio();
    412 	spi_transq_enqueue(&sc->sc_q, st);
    413 	if (sc->sc_running == FALSE)
    414 		imxspi_sched(sc);
    415 	splx(s);
    416 
    417 	return 0;
    418 }
    419 
    420