1155324Simp/*- 2155324Simp * Copyright (c) 2006 M. Warner Losh. All rights reserved. 3155324Simp * 4155324Simp * Redistribution and use in source and binary forms, with or without 5155324Simp * modification, are permitted provided that the following conditions 6155324Simp * are met: 7155324Simp * 1. Redistributions of source code must retain the above copyright 8155324Simp * notice, this list of conditions and the following disclaimer. 9155324Simp * 2. Redistributions in binary form must reproduce the above copyright 10155324Simp * notice, this list of conditions and the following disclaimer in the 11155324Simp * documentation and/or other materials provided with the distribution. 12155324Simp * 13185265Simp * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND 14185265Simp * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15185265Simp * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16185265Simp * ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE 17185265Simp * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18185265Simp * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19185265Simp * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20185265Simp * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21185265Simp * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22185265Simp * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23185265Simp * SUCH DAMAGE. 24155324Simp */ 25155324Simp 26155324Simp#include <sys/cdefs.h> 27155324Simp__FBSDID("$FreeBSD$"); 28155324Simp 29155324Simp#include <sys/param.h> 30155324Simp#include <sys/systm.h> 31155324Simp#include <sys/bus.h> 32155324Simp#include <sys/conf.h> 33155324Simp#include <sys/kernel.h> 34155324Simp#include <sys/lock.h> 35155324Simp#include <sys/mbuf.h> 36155324Simp#include <sys/malloc.h> 37155324Simp#include <sys/module.h> 38155324Simp#include <sys/mutex.h> 39155324Simp#include <sys/rman.h> 40155324Simp#include <machine/bus.h> 41155324Simp 42155324Simp#include <arm/at91/at91_twireg.h> 43187601Simp#include <arm/at91/at91var.h> 44155324Simp 45157563Simp#include <dev/iicbus/iiconf.h> 46157563Simp#include <dev/iicbus/iicbus.h> 47157563Simp#include "iicbus_if.h" 48157563Simp 49236080Smarius#define TWI_SLOW_CLOCK 1500 50236080Smarius#define TWI_FAST_CLOCK 45000 51236080Smarius#define TWI_FASTEST_CLOCK 90000 52167852Simp 53155324Simpstruct at91_twi_softc 54155324Simp{ 55155324Simp device_t dev; /* Myself */ 56155324Simp void *intrhand; /* Interrupt handle */ 57155324Simp struct resource *irq_res; /* IRQ resource */ 58155324Simp struct resource *mem_res; /* Memory resource */ 59155324Simp struct mtx sc_mtx; /* basically a perimeter lock */ 60164744Simp volatile uint32_t flags; 61155324Simp uint32_t cwgr; 62157563Simp int sc_started; 63157563Simp int twi_addr; 64157563Simp device_t iicbus; 65155324Simp}; 66155324Simp 67155324Simpstatic inline uint32_t 68155324SimpRD4(struct at91_twi_softc *sc, bus_size_t off) 69155324Simp{ 70236080Smarius 71155324Simp return bus_read_4(sc->mem_res, off); 72155324Simp} 73155324Simp 74155324Simpstatic inline void 75155324SimpWR4(struct at91_twi_softc *sc, bus_size_t off, uint32_t val) 76155324Simp{ 77236080Smarius 78155324Simp bus_write_4(sc->mem_res, off, val); 79155324Simp} 80155324Simp 81236080Smarius#define AT91_TWI_LOCK(_sc) mtx_lock(&(_sc)->sc_mtx) 82155324Simp#define AT91_TWI_UNLOCK(_sc) mtx_unlock(&(_sc)->sc_mtx) 83236080Smarius#define AT91_TWI_LOCK_INIT(_sc) \ 84155324Simp mtx_init(&_sc->sc_mtx, device_get_nameunit(_sc->dev), \ 85155324Simp "twi", MTX_DEF) 86236080Smarius#define AT91_TWI_LOCK_DESTROY(_sc) mtx_destroy(&_sc->sc_mtx); 87236080Smarius#define AT91_TWI_ASSERT_LOCKED(_sc) mtx_assert(&_sc->sc_mtx, MA_OWNED); 88236080Smarius#define AT91_TWI_ASSERT_UNLOCKED(_sc) mtx_assert(&_sc->sc_mtx, MA_NOTOWNED); 89236080Smarius#define TWI_DEF_CLK 100000 90155324Simp 91155324Simpstatic devclass_t at91_twi_devclass; 92155324Simp 93155324Simp/* bus entry points */ 94155324Simp 95155324Simpstatic int at91_twi_probe(device_t dev); 96155324Simpstatic int at91_twi_attach(device_t dev); 97155324Simpstatic int at91_twi_detach(device_t dev); 98155324Simpstatic void at91_twi_intr(void *); 99155324Simp 100155324Simp/* helper routines */ 101155324Simpstatic int at91_twi_activate(device_t dev); 102155324Simpstatic void at91_twi_deactivate(device_t dev); 103155324Simp 104155324Simpstatic int 105155324Simpat91_twi_probe(device_t dev) 106155324Simp{ 107236080Smarius 108155324Simp device_set_desc(dev, "TWI"); 109155324Simp return (0); 110155324Simp} 111155324Simp 112155324Simpstatic int 113155324Simpat91_twi_attach(device_t dev) 114155324Simp{ 115155324Simp struct at91_twi_softc *sc = device_get_softc(dev); 116155324Simp int err; 117155324Simp 118155324Simp sc->dev = dev; 119155324Simp err = at91_twi_activate(dev); 120155324Simp if (err) 121155324Simp goto out; 122155324Simp 123155324Simp AT91_TWI_LOCK_INIT(sc); 124155324Simp 125155324Simp /* 126155324Simp * Activate the interrupt 127155324Simp */ 128155324Simp err = bus_setup_intr(dev, sc->irq_res, INTR_TYPE_MISC | INTR_MPSAFE, 129166901Spiso NULL, at91_twi_intr, sc, &sc->intrhand); 130155324Simp if (err) { 131155324Simp AT91_TWI_LOCK_DESTROY(sc); 132155324Simp goto out; 133155324Simp } 134187601Simp sc->cwgr = TWI_CWGR_CKDIV(8 * at91_master_clock / TWI_FASTEST_CLOCK) | 135155324Simp TWI_CWGR_CHDIV(TWI_CWGR_DIV(TWI_DEF_CLK)) | 136155324Simp TWI_CWGR_CLDIV(TWI_CWGR_DIV(TWI_DEF_CLK)); 137155324Simp WR4(sc, TWI_CR, TWI_CR_SWRST); 138155324Simp WR4(sc, TWI_CR, TWI_CR_MSEN | TWI_CR_SVDIS); 139155324Simp WR4(sc, TWI_CWGR, sc->cwgr); 140157563Simp 141157563Simp if ((sc->iicbus = device_add_child(dev, "iicbus", -1)) == NULL) 142157563Simp device_printf(dev, "could not allocate iicbus instance\n"); 143157563Simp /* probe and attach the iicbus */ 144157563Simp bus_generic_attach(dev); 145237093Smariusout: 146155324Simp if (err) 147155324Simp at91_twi_deactivate(dev); 148155324Simp return (err); 149155324Simp} 150155324Simp 151155324Simpstatic int 152155324Simpat91_twi_detach(device_t dev) 153155324Simp{ 154157563Simp struct at91_twi_softc *sc; 155157563Simp int rv; 156157563Simp 157157563Simp sc = device_get_softc(dev); 158157563Simp at91_twi_deactivate(dev); 159157563Simp if (sc->iicbus && (rv = device_delete_child(dev, sc->iicbus)) != 0) 160157563Simp return (rv); 161157563Simp 162181303Sjhb AT91_TWI_LOCK_DESTROY(sc); 163181303Sjhb 164157563Simp return (0); 165155324Simp} 166155324Simp 167155324Simpstatic int 168155324Simpat91_twi_activate(device_t dev) 169155324Simp{ 170155324Simp struct at91_twi_softc *sc; 171155324Simp int rid; 172155324Simp 173155324Simp sc = device_get_softc(dev); 174155324Simp rid = 0; 175155324Simp sc->mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid, 176155324Simp RF_ACTIVE); 177155324Simp if (sc->mem_res == NULL) 178155324Simp goto errout; 179155324Simp rid = 0; 180155324Simp sc->irq_res = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid, 181155324Simp RF_ACTIVE); 182163523Simp if (sc->irq_res == NULL) 183155324Simp goto errout; 184155324Simp return (0); 185155324Simperrout: 186155324Simp at91_twi_deactivate(dev); 187155324Simp return (ENOMEM); 188155324Simp} 189155324Simp 190155324Simpstatic void 191155324Simpat91_twi_deactivate(device_t dev) 192155324Simp{ 193155324Simp struct at91_twi_softc *sc; 194155324Simp 195155324Simp sc = device_get_softc(dev); 196155324Simp if (sc->intrhand) 197155324Simp bus_teardown_intr(dev, sc->irq_res, sc->intrhand); 198155324Simp sc->intrhand = 0; 199155324Simp bus_generic_detach(sc->dev); 200155324Simp if (sc->mem_res) 201179375Simp bus_release_resource(dev, SYS_RES_MEMORY, 202155324Simp rman_get_rid(sc->mem_res), sc->mem_res); 203155324Simp sc->mem_res = 0; 204155324Simp if (sc->irq_res) 205155324Simp bus_release_resource(dev, SYS_RES_IRQ, 206155324Simp rman_get_rid(sc->irq_res), sc->irq_res); 207155324Simp sc->irq_res = 0; 208155324Simp return; 209155324Simp} 210155324Simp 211155324Simpstatic void 212155324Simpat91_twi_intr(void *xsc) 213155324Simp{ 214155324Simp struct at91_twi_softc *sc = xsc; 215155324Simp uint32_t status; 216155324Simp 217155324Simp status = RD4(sc, TWI_SR); 218155324Simp if (status == 0) 219155324Simp return; 220181303Sjhb AT91_TWI_LOCK(sc); 221164744Simp sc->flags |= status & (TWI_SR_OVRE | TWI_SR_UNRE | TWI_SR_NACK); 222155324Simp if (status & TWI_SR_RXRDY) 223164744Simp sc->flags |= TWI_SR_RXRDY; 224155324Simp if (status & TWI_SR_TXRDY) 225164744Simp sc->flags |= TWI_SR_TXRDY; 226164744Simp if (status & TWI_SR_TXCOMP) 227164744Simp sc->flags |= TWI_SR_TXCOMP; 228164744Simp WR4(sc, TWI_IDR, status); 229155324Simp wakeup(sc); 230181303Sjhb AT91_TWI_UNLOCK(sc); 231155324Simp return; 232155324Simp} 233155324Simp 234157563Simpstatic int 235162130Simpat91_twi_wait(struct at91_twi_softc *sc, uint32_t bit) 236155324Simp{ 237157563Simp int err = 0; 238164503Simp int counter = 100000; 239164744Simp uint32_t sr; 240157563Simp 241181303Sjhb AT91_TWI_ASSERT_LOCKED(sc); 242167852Simp while (!((sr = RD4(sc, TWI_SR)) & bit) && counter-- > 0 && 243167852Simp !(sr & TWI_SR_NACK)) 244164503Simp continue; 245163523Simp if (counter <= 0) 246164744Simp err = EBUSY; 247164744Simp else if (sr & TWI_SR_NACK) 248167852Simp err = ENXIO; // iic nack convention 249157563Simp return (err); 250157563Simp} 251157563Simp 252157563Simpstatic int 253157563Simpat91_twi_rst_card(device_t dev, u_char speed, u_char addr, u_char *oldaddr) 254157563Simp{ 255157563Simp struct at91_twi_softc *sc; 256164744Simp int clk; 257157563Simp 258157563Simp sc = device_get_softc(dev); 259181303Sjhb AT91_TWI_LOCK(sc); 260157563Simp if (oldaddr) 261157563Simp *oldaddr = sc->twi_addr; 262164744Simp sc->twi_addr = addr; 263157563Simp 264157563Simp /* 265157563Simp * speeds are for 1.5kb/s, 45kb/s and 90kb/s. 266157563Simp */ 267157563Simp switch (speed) { 268157563Simp case IIC_SLOW: 269167852Simp clk = TWI_SLOW_CLOCK; 270155324Simp break; 271157563Simp 272157563Simp case IIC_FAST: 273167852Simp clk = TWI_FAST_CLOCK; 274157563Simp break; 275157563Simp 276157563Simp case IIC_UNKNOWN: 277157563Simp case IIC_FASTEST: 278157563Simp default: 279167852Simp clk = TWI_FASTEST_CLOCK; 280157563Simp break; 281155324Simp } 282164744Simp sc->cwgr = TWI_CWGR_CKDIV(1) | TWI_CWGR_CHDIV(TWI_CWGR_DIV(clk)) | 283164744Simp TWI_CWGR_CLDIV(TWI_CWGR_DIV(clk)); 284157563Simp WR4(sc, TWI_CR, TWI_CR_SWRST); 285157563Simp WR4(sc, TWI_CR, TWI_CR_MSEN | TWI_CR_SVDIS); 286157563Simp WR4(sc, TWI_CWGR, sc->cwgr); 287164744Simp printf("setting cwgr to %#x\n", sc->cwgr); 288181303Sjhb AT91_TWI_UNLOCK(sc); 289155324Simp 290164503Simp return 0; 291157563Simp} 292157563Simp 293157563Simpstatic int 294194015Savgat91_twi_callback(device_t dev, int index, caddr_t data) 295157563Simp{ 296157563Simp int error = 0; 297157563Simp 298157563Simp switch (index) { 299157563Simp case IIC_REQUEST_BUS: 300155324Simp break; 301157563Simp 302157563Simp case IIC_RELEASE_BUS: 303157563Simp break; 304157563Simp 305155324Simp default: 306157563Simp error = EINVAL; 307155324Simp } 308157563Simp 309157563Simp return (error); 310155324Simp} 311155324Simp 312162130Simpstatic int 313162130Simpat91_twi_transfer(device_t dev, struct iic_msg *msgs, uint32_t nmsgs) 314162130Simp{ 315162130Simp struct at91_twi_softc *sc; 316164744Simp int i, len, err; 317162130Simp uint32_t rdwr; 318162130Simp uint8_t *buf; 319167852Simp uint32_t sr; 320162130Simp 321162130Simp sc = device_get_softc(dev); 322164744Simp err = 0; 323164744Simp AT91_TWI_LOCK(sc); 324162130Simp for (i = 0; i < nmsgs; i++) { 325162130Simp /* 326162130Simp * The linux atmel driver doesn't use the internal device 327162130Simp * address feature of twi. A separate i2c message needs to 328162130Simp * be written to use this. 329162130Simp * See http://lists.arm.linux.org.uk/pipermail/linux-arm-kernel/2004-September/024411.html 330164744Simp * for details. Upon reflection, we could use this as an 331164744Simp * optimization, but it is unclear the code bloat will 332164744Simp * result in faster/better operations. 333162130Simp */ 334162130Simp rdwr = (msgs[i].flags & IIC_M_RD) ? TWI_MMR_MREAD : 0; 335162130Simp WR4(sc, TWI_MMR, TWI_MMR_DADR(msgs[i].slave) | rdwr); 336162130Simp len = msgs[i].len; 337162130Simp buf = msgs[i].buf; 338167852Simp /* zero byte transfers aren't allowed */ 339167852Simp if (len == 0 || buf == NULL) { 340167852Simp err = EINVAL; 341167852Simp goto out; 342167852Simp } 343213203Sticso if (len == 1 && msgs[i].flags & IIC_M_RD) 344167852Simp WR4(sc, TWI_CR, TWI_CR_START | TWI_CR_STOP); 345167852Simp else 346167852Simp WR4(sc, TWI_CR, TWI_CR_START); 347162130Simp if (msgs[i].flags & IIC_M_RD) { 348167852Simp sr = RD4(sc, TWI_SR); 349167852Simp while (!(sr & TWI_SR_TXCOMP)) { 350167852Simp if ((sr = RD4(sc, TWI_SR)) & TWI_SR_RXRDY) { 351167852Simp len--; 352167852Simp *buf++ = RD4(sc, TWI_RHR) & 0xff; 353213201Sticso if (len == 1) 354167852Simp WR4(sc, TWI_CR, TWI_CR_STOP); 355167852Simp } 356162130Simp } 357167852Simp if (len > 0 || (sr & TWI_SR_NACK)) { 358167852Simp err = ENXIO; // iic nack convention 359167852Simp goto out; 360167852Simp } 361162130Simp } else { 362162130Simp while (len--) { 363167852Simp if ((err = at91_twi_wait(sc, TWI_SR_TXRDY))) 364164744Simp goto out; 365167852Simp WR4(sc, TWI_THR, *buf++); 366162130Simp } 367236082Smarius WR4(sc, TWI_CR, TWI_CR_STOP); 368162130Simp } 369164744Simp if ((err = at91_twi_wait(sc, TWI_SR_TXCOMP))) 370164744Simp break; 371162130Simp } 372237093Smariusout: 373164744Simp if (err) { 374167852Simp WR4(sc, TWI_CR, TWI_CR_SWRST); 375167852Simp WR4(sc, TWI_CR, TWI_CR_MSEN | TWI_CR_SVDIS); 376167852Simp WR4(sc, TWI_CWGR, sc->cwgr); 377164744Simp } 378164744Simp AT91_TWI_UNLOCK(sc); 379164744Simp return (err); 380162130Simp} 381162130Simp 382155324Simpstatic device_method_t at91_twi_methods[] = { 383155324Simp /* Device interface */ 384155324Simp DEVMETHOD(device_probe, at91_twi_probe), 385155324Simp DEVMETHOD(device_attach, at91_twi_attach), 386155324Simp DEVMETHOD(device_detach, at91_twi_detach), 387155324Simp 388157563Simp /* iicbus interface */ 389157563Simp DEVMETHOD(iicbus_callback, at91_twi_callback), 390157563Simp DEVMETHOD(iicbus_reset, at91_twi_rst_card), 391162130Simp DEVMETHOD(iicbus_transfer, at91_twi_transfer), 392236080Smarius DEVMETHOD_END 393155324Simp}; 394155324Simp 395155324Simpstatic driver_t at91_twi_driver = { 396155324Simp "at91_twi", 397155324Simp at91_twi_methods, 398155324Simp sizeof(struct at91_twi_softc), 399155324Simp}; 400155324Simp 401236080SmariusDRIVER_MODULE(at91_twi, atmelarm, at91_twi_driver, at91_twi_devclass, NULL, 402236080Smarius NULL); 403236080SmariusDRIVER_MODULE(iicbus, at91_twi, iicbus_driver, iicbus_devclass, NULL, NULL); 404166532SimpMODULE_DEPEND(at91_twi, iicbus, 1, 1, 1); 405