at91_twi.c revision 234293
1204076Spjd/*- 2204076Spjd * Copyright (c) 2006 M. Warner Losh. All rights reserved. 3211877Spjd * 4204076Spjd * Redistribution and use in source and binary forms, with or without 5204076Spjd * modification, are permitted provided that the following conditions 6204076Spjd * are met: 7204076Spjd * 1. Redistributions of source code must retain the above copyright 8204076Spjd * notice, this list of conditions and the following disclaimer. 9204076Spjd * 2. Redistributions in binary form must reproduce the above copyright 10204076Spjd * notice, this list of conditions and the following disclaimer in the 11204076Spjd * documentation and/or other materials provided with the distribution. 12204076Spjd * 13204076Spjd * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND 14204076Spjd * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15204076Spjd * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16204076Spjd * ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE 17204076Spjd * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18204076Spjd * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19204076Spjd * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20204076Spjd * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21204076Spjd * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22204076Spjd * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23204076Spjd * SUCH DAMAGE. 24204076Spjd */ 25204076Spjd 26204076Spjd#include <sys/cdefs.h> 27204076Spjd__FBSDID("$FreeBSD: head/sys/arm/at91/at91_twi.c 234293 2012-04-14 17:27:34Z marius $"); 28204076Spjd 29204076Spjd#include <sys/param.h> 30204076Spjd#include <sys/systm.h> 31204076Spjd#include <sys/bus.h> 32204076Spjd#include <sys/conf.h> 33204076Spjd#include <sys/kernel.h> 34204076Spjd#include <sys/lock.h> 35204076Spjd#include <sys/mbuf.h> 36204076Spjd#include <sys/malloc.h> 37204076Spjd#include <sys/module.h> 38204076Spjd#include <sys/mutex.h> 39204076Spjd#include <sys/rman.h> 40204076Spjd#include <machine/bus.h> 41204076Spjd 42204076Spjd#include <arm/at91/at91_twireg.h> 43204076Spjd#include <arm/at91/at91var.h> 44204076Spjd 45213009Spjd#include <dev/iicbus/iiconf.h> 46204076Spjd#include <dev/iicbus/iicbus.h> 47204076Spjd#include "iicbus_if.h" 48204076Spjd 49204076Spjd#define TWI_SLOW_CLOCK 1500 50204076Spjd#define TWI_FAST_CLOCK 45000 51204076Spjd#define TWI_FASTEST_CLOCK 90000 52204076Spjd 53204076Spjdstruct at91_twi_softc 54204076Spjd{ 55204076Spjd device_t dev; /* Myself */ 56204076Spjd void *intrhand; /* Interrupt handle */ 57212038Spjd struct resource *irq_res; /* IRQ resource */ 58204076Spjd struct resource *mem_res; /* Memory resource */ 59204076Spjd struct mtx sc_mtx; /* basically a perimeter lock */ 60204076Spjd volatile uint32_t flags; 61211977Spjd uint32_t cwgr; 62204076Spjd int sc_started; 63204076Spjd int twi_addr; 64204076Spjd device_t iicbus; 65204076Spjd}; 66204076Spjd 67204076Spjdstatic inline uint32_t 68219864SpjdRD4(struct at91_twi_softc *sc, bus_size_t off) 69219864Spjd{ 70204076Spjd 71204076Spjd return bus_read_4(sc->mem_res, off); 72204076Spjd} 73204076Spjd 74204076Spjdstatic inline void 75204076SpjdWR4(struct at91_twi_softc *sc, bus_size_t off, uint32_t val) 76204076Spjd{ 77204076Spjd 78211984Spjd bus_write_4(sc->mem_res, off, val); 79211984Spjd} 80204076Spjd 81204076Spjd#define AT91_TWI_LOCK(_sc) mtx_lock(&(_sc)->sc_mtx) 82204076Spjd#define AT91_TWI_UNLOCK(_sc) mtx_unlock(&(_sc)->sc_mtx) 83204076Spjd#define AT91_TWI_LOCK_INIT(_sc) \ 84204076Spjd mtx_init(&_sc->sc_mtx, device_get_nameunit(_sc->dev), \ 85204076Spjd "twi", MTX_DEF) 86204076Spjd#define AT91_TWI_LOCK_DESTROY(_sc) mtx_destroy(&_sc->sc_mtx); 87204076Spjd#define AT91_TWI_ASSERT_LOCKED(_sc) mtx_assert(&_sc->sc_mtx, MA_OWNED); 88204076Spjd#define AT91_TWI_ASSERT_UNLOCKED(_sc) mtx_assert(&_sc->sc_mtx, MA_NOTOWNED); 89204076Spjd#define TWI_DEF_CLK 100000 90204076Spjd 91204076Spjdstatic devclass_t at91_twi_devclass; 92204076Spjd 93204076Spjd/* bus entry points */ 94204076Spjd 95204076Spjdstatic int at91_twi_probe(device_t dev); 96204076Spjdstatic int at91_twi_attach(device_t dev); 97204076Spjdstatic int at91_twi_detach(device_t dev); 98204076Spjdstatic void at91_twi_intr(void *); 99204076Spjd 100204076Spjd/* helper routines */ 101204076Spjdstatic int at91_twi_activate(device_t dev); 102204076Spjdstatic void at91_twi_deactivate(device_t dev); 103204076Spjd 104204076Spjdstatic int 105204076Spjdat91_twi_probe(device_t dev) 106204076Spjd{ 107204076Spjd 108204076Spjd device_set_desc(dev, "TWI"); 109204076Spjd return (0); 110211877Spjd} 111211877Spjd 112211877Spjdstatic int 113211877Spjdat91_twi_attach(device_t dev) 114211877Spjd{ 115211877Spjd struct at91_twi_softc *sc = device_get_softc(dev); 116211877Spjd int err; 117211877Spjd 118211877Spjd sc->dev = dev; 119211877Spjd err = at91_twi_activate(dev); 120211877Spjd if (err) 121211877Spjd goto out; 122211877Spjd 123211877Spjd AT91_TWI_LOCK_INIT(sc); 124211877Spjd 125211877Spjd /* 126211877Spjd * Activate the interrupt 127211877Spjd */ 128211877Spjd err = bus_setup_intr(dev, sc->irq_res, INTR_TYPE_MISC | INTR_MPSAFE, 129211877Spjd NULL, at91_twi_intr, sc, &sc->intrhand); 130204076Spjd if (err) { 131204076Spjd AT91_TWI_LOCK_DESTROY(sc); 132204076Spjd goto out; 133204076Spjd } 134204076Spjd sc->cwgr = TWI_CWGR_CKDIV(8 * at91_master_clock / TWI_FASTEST_CLOCK) | 135204076Spjd TWI_CWGR_CHDIV(TWI_CWGR_DIV(TWI_DEF_CLK)) | 136204076Spjd TWI_CWGR_CLDIV(TWI_CWGR_DIV(TWI_DEF_CLK)); 137204076Spjd WR4(sc, TWI_CR, TWI_CR_SWRST); 138204076Spjd WR4(sc, TWI_CR, TWI_CR_MSEN | TWI_CR_SVDIS); 139204076Spjd WR4(sc, TWI_CWGR, sc->cwgr); 140204076Spjd 141204076Spjd if ((sc->iicbus = device_add_child(dev, "iicbus", -1)) == NULL) 142204076Spjd device_printf(dev, "could not allocate iicbus instance\n"); 143204076Spjd /* probe and attach the iicbus */ 144204076Spjd bus_generic_attach(dev); 145204076Spjdout: 146204076Spjd if (err) 147204076Spjd at91_twi_deactivate(dev); 148204076Spjd return (err); 149204076Spjd} 150204076Spjd 151204076Spjdstatic int 152204076Spjdat91_twi_detach(device_t dev) 153204076Spjd{ 154204076Spjd struct at91_twi_softc *sc; 155210879Spjd int rv; 156210879Spjd 157210879Spjd sc = device_get_softc(dev); 158204076Spjd at91_twi_deactivate(dev); 159204076Spjd if (sc->iicbus && (rv = device_delete_child(dev, sc->iicbus)) != 0) 160204076Spjd return (rv); 161204076Spjd 162210879Spjd AT91_TWI_LOCK_DESTROY(sc); 163210879Spjd 164210879Spjd return (0); 165204076Spjd} 166204076Spjd 167204076Spjdstatic int 168204076Spjdat91_twi_activate(device_t dev) 169204076Spjd{ 170204076Spjd struct at91_twi_softc *sc; 171204076Spjd int rid; 172204076Spjd 173204076Spjd sc = device_get_softc(dev); 174204076Spjd rid = 0; 175204076Spjd sc->mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid, 176204076Spjd RF_ACTIVE); 177204076Spjd if (sc->mem_res == NULL) 178204076Spjd goto errout; 179204076Spjd rid = 0; 180204076Spjd sc->irq_res = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid, 181204076Spjd RF_ACTIVE); 182204076Spjd if (sc->irq_res == NULL) 183204076Spjd goto errout; 184204076Spjd return (0); 185204076Spjderrout: 186223181Strociny at91_twi_deactivate(dev); 187220271Spjd return (ENOMEM); 188220271Spjd} 189220271Spjd 190223181Strocinystatic void 191220271Spjdat91_twi_deactivate(device_t dev) 192204076Spjd{ 193204076Spjd struct at91_twi_softc *sc; 194204076Spjd 195204076Spjd sc = device_get_softc(dev); 196204076Spjd if (sc->intrhand) 197204076Spjd bus_teardown_intr(dev, sc->irq_res, sc->intrhand); 198204076Spjd sc->intrhand = 0; 199204076Spjd bus_generic_detach(sc->dev); 200204076Spjd if (sc->mem_res) 201204076Spjd bus_release_resource(dev, SYS_RES_MEMORY, 202204076Spjd rman_get_rid(sc->mem_res), sc->mem_res); 203204076Spjd sc->mem_res = 0; 204204076Spjd if (sc->irq_res) 205204076Spjd bus_release_resource(dev, SYS_RES_IRQ, 206204076Spjd rman_get_rid(sc->irq_res), sc->irq_res); 207204076Spjd sc->irq_res = 0; 208204076Spjd return; 209204076Spjd} 210204076Spjd 211204076Spjdstatic void 212204076Spjdat91_twi_intr(void *xsc) 213204076Spjd{ 214204076Spjd struct at91_twi_softc *sc = xsc; 215204076Spjd uint32_t status; 216204076Spjd 217204076Spjd status = RD4(sc, TWI_SR); 218204076Spjd if (status == 0) 219204076Spjd return; 220204076Spjd AT91_TWI_LOCK(sc); 221204076Spjd sc->flags |= status & (TWI_SR_OVRE | TWI_SR_UNRE | TWI_SR_NACK); 222204076Spjd if (status & TWI_SR_RXRDY) 223204076Spjd sc->flags |= TWI_SR_RXRDY; 224204076Spjd if (status & TWI_SR_TXRDY) 225204076Spjd sc->flags |= TWI_SR_TXRDY; 226204076Spjd if (status & TWI_SR_TXCOMP) 227204076Spjd sc->flags |= TWI_SR_TXCOMP; 228204076Spjd WR4(sc, TWI_IDR, status); 229204076Spjd wakeup(sc); 230204076Spjd AT91_TWI_UNLOCK(sc); 231204076Spjd return; 232204076Spjd} 233204076Spjd 234204076Spjdstatic int 235204076Spjdat91_twi_wait(struct at91_twi_softc *sc, uint32_t bit) 236204076Spjd{ 237204076Spjd int err = 0; 238204076Spjd int counter = 100000; 239204076Spjd uint32_t sr; 240204076Spjd 241204076Spjd AT91_TWI_ASSERT_LOCKED(sc); 242204076Spjd while (!((sr = RD4(sc, TWI_SR)) & bit) && counter-- > 0 && 243204076Spjd !(sr & TWI_SR_NACK)) 244204076Spjd continue; 245204076Spjd if (counter <= 0) 246204076Spjd err = EBUSY; 247204076Spjd else if (sr & TWI_SR_NACK) 248204076Spjd err = ENXIO; // iic nack convention 249204076Spjd return (err); 250214284Spjd} 251214284Spjd 252214284Spjdstatic int 253214284Spjdat91_twi_rst_card(device_t dev, u_char speed, u_char addr, u_char *oldaddr) 254204076Spjd{ 255218138Spjd struct at91_twi_softc *sc; 256204076Spjd int clk; 257204076Spjd 258204076Spjd sc = device_get_softc(dev); 259214284Spjd AT91_TWI_LOCK(sc); 260214284Spjd if (oldaddr) 261214284Spjd *oldaddr = sc->twi_addr; 262214284Spjd sc->twi_addr = addr; 263214284Spjd 264214284Spjd /* 265214284Spjd * speeds are for 1.5kb/s, 45kb/s and 90kb/s. 266220865Spjd */ 267204076Spjd switch (speed) { 268219830Spjd case IIC_SLOW: 269219830Spjd clk = TWI_SLOW_CLOCK; 270219830Spjd break; 271219830Spjd 272219830Spjd case IIC_FAST: 273219830Spjd clk = TWI_FAST_CLOCK; 274219830Spjd break; 275219830Spjd 276219830Spjd case IIC_UNKNOWN: 277219830Spjd case IIC_FASTEST: 278219830Spjd default: 279219830Spjd clk = TWI_FASTEST_CLOCK; 280219831Spjd break; 281219830Spjd } 282204076Spjd sc->cwgr = TWI_CWGR_CKDIV(1) | TWI_CWGR_CHDIV(TWI_CWGR_DIV(clk)) | 283204076Spjd TWI_CWGR_CLDIV(TWI_CWGR_DIV(clk)); 284204076Spjd WR4(sc, TWI_CR, TWI_CR_SWRST); 285204076Spjd WR4(sc, TWI_CR, TWI_CR_MSEN | TWI_CR_SVDIS); 286219843Spjd WR4(sc, TWI_CWGR, sc->cwgr); 287204076Spjd printf("setting cwgr to %#x\n", sc->cwgr); 288204076Spjd AT91_TWI_UNLOCK(sc); 289204076Spjd 290204076Spjd return 0; 291204076Spjd} 292204076Spjd 293204076Spjdstatic int 294204076Spjdat91_twi_callback(device_t dev, int index, caddr_t data) 295204076Spjd{ 296204076Spjd int error = 0; 297204076Spjd 298204076Spjd switch (index) { 299204076Spjd case IIC_REQUEST_BUS: 300204076Spjd break; 301204076Spjd 302204076Spjd case IIC_RELEASE_BUS: 303204076Spjd break; 304204076Spjd 305204076Spjd default: 306204076Spjd error = EINVAL; 307204076Spjd } 308204076Spjd 309204076Spjd return (error); 310204076Spjd} 311204076Spjd 312204076Spjdstatic int 313204076Spjdat91_twi_transfer(device_t dev, struct iic_msg *msgs, uint32_t nmsgs) 314204076Spjd{ 315204076Spjd struct at91_twi_softc *sc; 316204076Spjd int i, len, err; 317204076Spjd uint32_t rdwr; 318204076Spjd uint8_t *buf; 319204076Spjd uint32_t sr; 320204076Spjd 321204076Spjd sc = device_get_softc(dev); 322204076Spjd err = 0; 323204076Spjd AT91_TWI_LOCK(sc); 324204076Spjd for (i = 0; i < nmsgs; i++) { 325204076Spjd /* 326204076Spjd * The linux atmel driver doesn't use the internal device 327204076Spjd * address feature of twi. A separate i2c message needs to 328204076Spjd * be written to use this. 329218138Spjd * See http://lists.arm.linux.org.uk/pipermail/linux-arm-kernel/2004-September/024411.html 330204076Spjd * for details. Upon reflection, we could use this as an 331204076Spjd * optimization, but it is unclear the code bloat will 332204076Spjd * result in faster/better operations. 333204076Spjd */ 334204076Spjd rdwr = (msgs[i].flags & IIC_M_RD) ? TWI_MMR_MREAD : 0; 335204076Spjd WR4(sc, TWI_MMR, TWI_MMR_DADR(msgs[i].slave) | rdwr); 336204076Spjd len = msgs[i].len; 337204076Spjd buf = msgs[i].buf; 338204076Spjd /* zero byte transfers aren't allowed */ 339204076Spjd if (len == 0 || buf == NULL) { 340204076Spjd err = EINVAL; 341204076Spjd goto out; 342204076Spjd } 343204076Spjd if (len == 1 && msgs[i].flags & IIC_M_RD) 344204076Spjd WR4(sc, TWI_CR, TWI_CR_START | TWI_CR_STOP); 345204076Spjd else 346204076Spjd WR4(sc, TWI_CR, TWI_CR_START); 347204076Spjd if (msgs[i].flags & IIC_M_RD) { 348220007Spjd sr = RD4(sc, TWI_SR); 349204076Spjd while (!(sr & TWI_SR_TXCOMP)) { 350214276Spjd if ((sr = RD4(sc, TWI_SR)) & TWI_SR_RXRDY) { 351204076Spjd len--; 352204076Spjd *buf++ = RD4(sc, TWI_RHR) & 0xff; 353214275Spjd if (len == 1) 354214275Spjd WR4(sc, TWI_CR, TWI_CR_STOP); 355209182Spjd } 356223181Strociny } 357220271Spjd if (len > 0 || (sr & TWI_SR_NACK)) { 358220271Spjd err = ENXIO; // iic nack convention 359220271Spjd goto out; 360223181Strociny } 361204076Spjd } else { 362204076Spjd while (len--) { 363204076Spjd if ((err = at91_twi_wait(sc, TWI_SR_TXRDY))) 364212038Spjd goto out; 365204076Spjd WR4(sc, TWI_THR, *buf++); 366204076Spjd } 367204076Spjd WR4(sc, TWI_CR, TWI_CR_STOP); 368204076Spjd } 369204076Spjd if ((err = at91_twi_wait(sc, TWI_SR_TXCOMP))) 370204076Spjd break; 371204076Spjd } 372213009Spjdout: 373204076Spjd if (err) { 374204076Spjd WR4(sc, TWI_CR, TWI_CR_SWRST); 375219482Strociny WR4(sc, TWI_CR, TWI_CR_MSEN | TWI_CR_SVDIS); 376204076Spjd WR4(sc, TWI_CWGR, sc->cwgr); 377204076Spjd } 378204076Spjd AT91_TWI_UNLOCK(sc); 379204076Spjd return (err); 380219818Spjd} 381204076Spjd 382204076Spjdstatic device_method_t at91_twi_methods[] = { 383204076Spjd /* Device interface */ 384204076Spjd DEVMETHOD(device_probe, at91_twi_probe), 385212038Spjd DEVMETHOD(device_attach, at91_twi_attach), 386212038Spjd DEVMETHOD(device_detach, at91_twi_detach), 387212038Spjd 388219818Spjd /* iicbus interface */ 389212038Spjd DEVMETHOD(iicbus_callback, at91_twi_callback), 390212038Spjd DEVMETHOD(iicbus_reset, at91_twi_rst_card), 391212038Spjd DEVMETHOD(iicbus_transfer, at91_twi_transfer), 392212038Spjd DEVMETHOD_END 393204076Spjd}; 394204076Spjd 395204076Spjdstatic driver_t at91_twi_driver = { 396204076Spjd "at91_twi", 397204076Spjd at91_twi_methods, 398204076Spjd sizeof(struct at91_twi_softc), 399204076Spjd}; 400204076Spjd 401204076SpjdDRIVER_MODULE(at91_twi, atmelarm, at91_twi_driver, at91_twi_devclass, NULL, 402204076Spjd NULL); 403204076SpjdDRIVER_MODULE(iicbus, at91_twi, iicbus_driver, iicbus_devclass, NULL, NULL); 404204076SpjdMODULE_DEPEND(at91_twi, iicbus, 1, 1, 1); 405204076Spjd