1 files changed, 402 insertions, 0 deletions
diff --git a/sys/dev/altera/sdcard/altera_sdcard.c b/sys/dev/altera/sdcard/altera_sdcard.c
new file mode 100644
index 0000000..4572206
--- /dev/null
+++ b/sys/dev/altera/sdcard/altera_sdcard.c
@@ -0,0 +1,402 @@
+/*-
+ * Copyright (c) 2012 Robert N. M. Watson
+ * All rights reserved.
+ *
+ * This software was developed by SRI International and the University of
+ * Cambridge Computer Laboratory under DARPA/AFRL contract (FA8750-10-C-0237)
+ * ("CTSRD"), as part of the DARPA CRASH research programme.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/param.h>
+#include <sys/bus.h>
+#include <sys/condvar.h>
+#include <sys/conf.h>
+#include <sys/bio.h>
+#include <sys/kernel.h>
+#include <sys/lock.h>
+#include <sys/malloc.h>
+#include <sys/module.h>
+#include <sys/mutex.h>
+#include <sys/rman.h>
+#include <sys/systm.h>
+#include <sys/taskqueue.h>
+
+#include <machine/bus.h>
+#include <machine/resource.h>
+
+#include <geom/geom_disk.h>
+
+#include <dev/altera/sdcard/altera_sdcard.h>
+
+/*
+ * Device driver for the Altera University Program Secure Data Card IP Core,
+ * as described in the similarly named SOPC Builder IP Core specification.
+ * This soft core is not a full SD host controller interface (SDHCI) but
+ * instead provides a set of memory mapped registers and memory buffer that
+ * mildly abstract the SD Card protocol, but without providing DMA or
+ * interrupts.  However, it does hide the details of voltage and
+ * communications negotiation.  This driver implements disk(9), but due to the
+ * lack of interrupt support, must rely on timer-driven polling to determine
+ * when I/Os have completed.
+ *
+ * TODO:
+ *
+ * 1. Implement DISKFLAG_CANDELETE / SD Card sector erase support.
+ * 2. Implement d_ident from SD Card CID serial number field.
+ * 3. Handle read-only SD Cards.
+ * 4. Tune timeouts based on real-world SD Card speeds.
+ */
+
+void
+altera_sdcard_attach(struct altera_sdcard_softc *sc)
+{
+
+	ALTERA_SDCARD_LOCK_INIT(sc);
+	ALTERA_SDCARD_CONDVAR_INIT(sc);
+	sc->as_disk = NULL;
+	bioq_init(&sc->as_bioq);
+	sc->as_currentbio = NULL;
+	sc->as_state = ALTERA_SDCARD_STATE_NOCARD;
+	sc->as_taskqueue = taskqueue_create("altera_sdcardc taskq", M_WAITOK,
+	    taskqueue_thread_enqueue, &sc->as_taskqueue);
+	taskqueue_start_threads(&sc->as_taskqueue, 1, PI_DISK,
+	    "altera_sdcardc%d taskqueue", sc->as_unit);
+	TIMEOUT_TASK_INIT(sc->as_taskqueue, &sc->as_task, 0,
+	    altera_sdcard_task, sc);
+
+	/*
+	 * Kick off timer-driven processing with a manual poll so that we
+	 * synchronously detect an already-inserted SD Card during the boot or
+	 * other driver attach point.
+	 */
+	altera_sdcard_task(sc, 1);
+}
+
+void
+altera_sdcard_detach(struct altera_sdcard_softc *sc)
+{
+
+	KASSERT(sc->as_taskqueue != NULL, ("%s: taskqueue not present",
+	    __func__));
+
+	/*
+	 * Winding down the driver on detach is a bit complex.  Update the
+	 * flags to indicate that a detach has been requested, and then wait
+	 * for in-progress I/O to wind down before continuing.
+	 */
+	ALTERA_SDCARD_LOCK(sc);
+	sc->as_flags |= ALTERA_SDCARD_FLAG_DETACHREQ;
+	while (sc->as_state != ALTERA_SDCARD_STATE_DETACHED)
+		ALTERA_SDCARD_CONDVAR_WAIT(sc);
+	ALTERA_SDCARD_UNLOCK(sc);
+
+	/*
+	 * Now wait for the possibly still executing taskqueue to drain.  In
+	 * principle no more events will be scheduled as we've transitioned to
+	 * a detached state, but there might still be a request in execution.
+	 */
+	while (taskqueue_cancel_timeout(sc->as_taskqueue, &sc->as_task, NULL))
+		taskqueue_drain_timeout(sc->as_taskqueue, &sc->as_task);
+
+	/*
+	 * Simulate a disk removal if one is present to deal with any pending
+	 * or queued I/O.
+	 */
+	if (sc->as_disk != NULL)
+		altera_sdcard_disk_remove(sc);
+	KASSERT(bioq_first(&sc->as_bioq) == NULL,
+	    ("%s: non-empty bioq", __func__));
+
+	/*
+	 * Free any remaining allocated resources.
+	 */
+	taskqueue_free(sc->as_taskqueue);
+	sc->as_taskqueue = NULL;
+	ALTERA_SDCARD_CONDVAR_DESTROY(sc);
+	ALTERA_SDCARD_LOCK_DESTROY(sc);
+}
+
+/*
+ * Set up and start the next I/O.  Transition to the I/O state, but allow the
+ * caller to schedule the next timeout, as this may be called either from an
+ * initial attach context, or from the task queue, which requires different
+ * behaviour.
+ */
+static void
+altera_sdcard_nextio(struct altera_sdcard_softc *sc)
+{
+	struct bio *bp;
+
+	ALTERA_SDCARD_LOCK_ASSERT(sc);
+	KASSERT(sc->as_currentbio == NULL,
+	    ("%s: bio already active", __func__));
+
+	bp = bioq_takefirst(&sc->as_bioq);
+	if (bp == NULL)
+		panic("%s: bioq empty", __func__);
+	altera_sdcard_io_start(sc, bp);
+	sc->as_state = ALTERA_SDCARD_STATE_IO;
+}
+
+static void
+altera_sdcard_task_nocard(struct altera_sdcard_softc *sc)
+{
+
+	ALTERA_SDCARD_LOCK_ASSERT(sc);
+
+	/*
+	 * Handle device driver detach.
+	 */
+	if (sc->as_flags & ALTERA_SDCARD_FLAG_DETACHREQ) {
+		sc->as_state = ALTERA_SDCARD_STATE_DETACHED;
+		return;
+	}
+
+	/*
+	 * If there is no card insertion, remain in NOCARD.
+	 */
+	if (!(altera_sdcard_read_asr(sc) & ALTERA_SDCARD_ASR_CARDPRESENT))
+		return;
+
+	/*
+	 * Read the CSD -- it may contain values that the driver can't handle,
+	 * either because of an unsupported version/feature, or because the
+	 * card is misbehaving.  This triggers a transition to
+	 * ALTERA_SDCARD_STATE_BADCARD.  We rely on the CSD read to print a
+	 * banner about how the card is problematic, since it has more
+	 * information.  The bad card state allows us to print that banner
+	 * once rather than each time we notice the card is there, and still
+	 * bad.
+	 */
+	if (altera_sdcard_read_csd(sc) != 0) {
+		sc->as_state = ALTERA_SDCARD_STATE_BADCARD;
+		return;
+	}
+
+	/*
+	 * Process card insertion and upgrade to the IDLE state.
+	 */
+	altera_sdcard_disk_insert(sc);
+	sc->as_state = ALTERA_SDCARD_STATE_IDLE;
+}
+
+static void
+altera_sdcard_task_badcard(struct altera_sdcard_softc *sc)
+{
+
+	ALTERA_SDCARD_LOCK_ASSERT(sc);
+
+	/*
+	 * Handle device driver detach.
+	 */
+	if (sc->as_flags & ALTERA_SDCARD_FLAG_DETACHREQ) {
+		sc->as_state = ALTERA_SDCARD_STATE_DETACHED;
+		return;
+	}
+
+	/*
+	 * Handle safe card removal -- no teardown is required, just a state
+	 * transition.
+	 */
+	if (!(altera_sdcard_read_asr(sc) & ALTERA_SDCARD_ASR_CARDPRESENT))
+		sc->as_state = ALTERA_SDCARD_STATE_NOCARD;
+}
+
+static void
+altera_sdcard_task_idle(struct altera_sdcard_softc *sc)
+{
+
+	ALTERA_SDCARD_LOCK_ASSERT(sc);
+
+	/*
+	 * Handle device driver detach.
+	 */
+	if (sc->as_flags & ALTERA_SDCARD_FLAG_DETACHREQ) {
+		sc->as_state = ALTERA_SDCARD_STATE_DETACHED;
+		return;
+	}
+
+	/*
+	 * Handle safe card removal.
+	 */
+	if (!(altera_sdcard_read_asr(sc) & ALTERA_SDCARD_ASR_CARDPRESENT)) {
+		altera_sdcard_disk_remove(sc);
+		sc->as_state = ALTERA_SDCARD_STATE_NOCARD;
+	}
+}
+
+static void
+altera_sdcard_task_io(struct altera_sdcard_softc *sc)
+{
+	uint16_t asr;
+
+	ALTERA_SDCARD_LOCK_ASSERT(sc);
+	KASSERT(sc->as_currentbio != NULL, ("%s: no current I/O", __func__));
+
+	asr = altera_sdcard_read_asr(sc);
+
+	/*
+	 * Check for unexpected card removal during an I/O.
+	 */
+	if (!(asr & ALTERA_SDCARD_ASR_CARDPRESENT)) {
+		altera_sdcard_disk_remove(sc);
+		if (sc->as_flags & ALTERA_SDCARD_FLAG_DETACHREQ)
+			sc->as_state = ALTERA_SDCARD_STATE_DETACHED;
+		else
+			sc->as_state = ALTERA_SDCARD_STATE_NOCARD;
+		return;
+	}
+
+	/*
+	 * If the I/O isn't complete, remain in the IO state without further
+	 * action, even if DETACHREQ is in flight.
+	 */
+	if (asr & ALTERA_SDCARD_ASR_CMDINPROGRESS)
+		return;
+
+	/*
+	 * Handle various forms of I/O completion, successful and otherwise.
+	 * The I/O layer may restart the transaction if an error occurred, in
+	 * which case remain in the IO state and reschedule.
+	 */
+	if (!altera_sdcard_io_complete(sc, asr))
+		return;
+
+	/*
+	 * Now that I/O is complete, process detach requests in preference to
+	 * starting new I/O.
+	 */
+	if (sc->as_flags & ALTERA_SDCARD_FLAG_DETACHREQ) {
+		sc->as_state = ALTERA_SDCARD_STATE_DETACHED;
+		return;
+	}
+
+	/*
+	 * Finally, either start the next I/O or transition to the IDLE state.
+	 */
+	if (bioq_first(&sc->as_bioq) != NULL)
+		altera_sdcard_nextio(sc);
+	else
+		sc->as_state = ALTERA_SDCARD_STATE_IDLE;
+}
+
+static void
+altera_sdcard_task_rechedule(struct altera_sdcard_softc *sc)
+{
+	int interval;
+
+	/*
+	 * Reschedule based on new state.  Or not, if detaching the device
+	 * driver.  Treat a bad card as though it were no card at all.
+	 */
+	switch (sc->as_state) {
+	case ALTERA_SDCARD_STATE_NOCARD:
+	case ALTERA_SDCARD_STATE_BADCARD:
+		interval = ALTERA_SDCARD_TIMEOUT_NOCARD;
+		break;
+
+	case ALTERA_SDCARD_STATE_IDLE:
+		interval = ALTERA_SDCARD_TIMEOUT_IDLE;
+		break;
+
+	case ALTERA_SDCARD_STATE_IO:
+		if (sc->as_flags & ALTERA_SDCARD_FLAG_IOERROR)
+			interval = ALTERA_SDCARD_TIMEOUT_IOERROR;
+		else
+			interval = ALTERA_SDCARD_TIMEOUT_IO;
+		break;
+
+	default:
+		panic("%s: invalid exit state %d", __func__, sc->as_state);
+	}
+	taskqueue_enqueue_timeout(sc->as_taskqueue, &sc->as_task, interval);
+}
+
+/*
+ * Because the Altera SD Card IP Core doesn't support interrupts, we do all
+ * asynchronous work from a timeout.  Poll at two different rates -- an
+ * infrequent check for card insertion status changes, and a frequent one for
+ * I/O completion.  The task should never start in DETACHED, as that would
+ * imply that a previous instance failed to cancel rather than reschedule.
+ */
+void
+altera_sdcard_task(void *arg, int pending)
+{
+	struct altera_sdcard_softc *sc;
+
+	sc = arg;
+	KASSERT(sc->as_state != ALTERA_SDCARD_STATE_DETACHED,
+	    ("%s: already in detached", __func__));
+
+	ALTERA_SDCARD_LOCK(sc);
+	switch (sc->as_state) {
+	case ALTERA_SDCARD_STATE_NOCARD:
+		altera_sdcard_task_nocard(sc);
+		break;
+
+	case ALTERA_SDCARD_STATE_BADCARD:
+		altera_sdcard_task_badcard(sc);
+		break;
+
+	case ALTERA_SDCARD_STATE_IDLE:
+		altera_sdcard_task_idle(sc);
+		break;
+
+	case ALTERA_SDCARD_STATE_IO:
+		altera_sdcard_task_io(sc);
+		break;
+
+	default:
+		panic("%s: invalid enter state %d", __func__, sc->as_state);
+	}
+
+	/*
+	 * If we have transitioned to DETACHED, signal the detach thread and
+	 * cancel the timeout-driven task.  Otherwise reschedule on an
+	 * appropriate timeout.
+	 */
+	if (sc->as_state == ALTERA_SDCARD_STATE_DETACHED)
+		ALTERA_SDCARD_CONDVAR_SIGNAL(sc);
+	else
+		altera_sdcard_task_rechedule(sc);
+	ALTERA_SDCARD_UNLOCK(sc);
+}
+
+void
+altera_sdcard_start(struct altera_sdcard_softc *sc)
+{
+
+	ALTERA_SDCARD_LOCK_ASSERT(sc);
+
+	KASSERT(sc->as_state == ALTERA_SDCARD_STATE_IDLE,
+	    ("%s: starting when not IDLE", __func__));
+
+	taskqueue_cancel_timeout(sc->as_taskqueue, &sc->as_task, NULL);
+	altera_sdcard_nextio(sc);
+	taskqueue_enqueue_timeout(sc->as_taskqueue, &sc->as_task,
+	    ALTERA_SDCARD_TIMEOUT_IO);
+}