@@ -1865,7 +1865,9 @@ M: Martin Povišer <povik+lin@cutebit.org>
L: asahi@lists.linux.dev
L: alsa-devel@alsa-project.org (moderated for non-subscribers)
S: Maintained
+F: Documentation/devicetree/bindings/dma/apple,sio.yaml
F: Documentation/devicetree/bindings/sound/apple,*
+F: drivers/dma/apple-sio.c
F: sound/soc/apple/*
F: sound/soc/codecs/cs42l83-i2c.c
@@ -93,6 +93,16 @@ config APPLE_ADMAC
help
Enable support for Audio DMA Controller found on Apple Silicon SoCs.
+config APPLE_SIO
+ tristate "Apple SIO support"
+ depends on ARCH_APPLE || COMPILE_TEST
+ depends on APPLE_RTKIT
+ select DMA_ENGINE
+ default ARCH_APPLE
+ help
+ Enable support for the SIO coprocessor found on Apple Silicon SoCs
+ where it provides DMA services.
+
config AT_HDMAC
tristate "Atmel AHB DMA support"
depends on ARCH_AT91
@@ -18,6 +18,7 @@ obj-$(CONFIG_AMBA_PL08X) += amba-pl08x.o
obj-$(CONFIG_AMCC_PPC440SPE_ADMA) += ppc4xx/
obj-$(CONFIG_AMD_PTDMA) += ptdma/
obj-$(CONFIG_APPLE_ADMAC) += apple-admac.o
+obj-$(CONFIG_APPLE_SIO) += apple-sio.o
obj-$(CONFIG_AT_HDMAC) += at_hdmac.o
obj-$(CONFIG_AT_XDMAC) += at_xdmac.o
obj-$(CONFIG_AXI_DMAC) += dma-axi-dmac.o
new file mode 100644
@@ -0,0 +1,956 @@
+// SPDX-License-Identifier: GPL-2.0-only OR MIT
+/*
+ * Driver for SIO coprocessor on t8103 (M1) and other Apple SoCs
+ *
+ * Copyright (C) The Asahi Linux Contributors
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bits.h>
+#include <linux/completion.h>
+#include <linux/device.h>
+#include <linux/dma-mapping.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/of_dma.h>
+#include <linux/soc/apple/rtkit.h>
+
+#include "dmaengine.h"
+
+#define NCHANNELS_MAX 0x80
+
+#define REG_CPU_CONTROL 0x44
+#define CPU_CONTROL_RUN BIT(4)
+
+#define SIOMSG_DATA GENMASK(63, 32)
+#define SIOMSG_TYPE GENMASK(23, 16)
+#define SIOMSG_PARAM GENMASK(31, 24)
+#define SIOMSG_TAG GENMASK(13, 8)
+#define SIOMSG_EP GENMASK(7, 0)
+
+#define EP_SIO 0x20
+
+#define MSG_START 0x2
+#define MSG_SETUP 0x3
+#define MSG_CONFIGURE 0x5
+#define MSG_ISSUE 0x6
+#define MSG_TERMINATE 0x8
+#define MSG_ACK 0x65
+#define MSG_NACK 0x66
+#define MSG_STARTED 0x67
+#define MSG_REPORT 0x68
+
+#define SIO_CALL_TIMEOUT_MS 100
+#define SIO_SHMEM_SIZE 0x1000
+#define SIO_NO_DESC_SLOTS 64
+
+/*
+ * There are two kinds of 'transaction descriptors' in play here.
+ *
+ * There's the struct sio_tx, and the struct dma_async_tx_descriptor embedded
+ * inside, which jointly represent a transaction to the dmaengine subsystem.
+ * At this time we only support those transactions to be cyclic.
+ *
+ * Then there are the coprocessor descriptors, which is what the coprocessor
+ * knows and understands. These don't seem to have a cyclic regime, so we can't
+ * map the dmaengine transaction on an exact coprocessor counterpart. Instead
+ * we continually queue up many coprocessor descriptors to implement a cyclic
+ * transaction.
+ *
+ * The number below is the maximum of how far ahead (how many) coprocessor
+ * descriptors we should be queuing up, per channel, for a cyclic transaction.
+ * Basically it's a made-up number.
+ */
+#define SIO_MAX_NINFLIGHT 4
+
+struct sio_coproc_desc {
+ u32 pad1;
+ u32 flag;
+ u64 unk;
+ u64 iova;
+ u64 size;
+ u64 pad2;
+ u64 pad3;
+} __packed;
+static_assert(sizeof(struct sio_coproc_desc) == 48);
+
+struct sio_shmem_chan_config {
+ u32 datashape;
+ u32 timeout;
+ u32 fifo;
+ u32 threshold;
+ u32 limit;
+} __packed;
+
+struct sio_data;
+struct sio_tx;
+
+struct sio_chan {
+ unsigned int no;
+ struct sio_data *host;
+ struct dma_chan chan;
+ struct tasklet_struct tasklet;
+ struct work_struct terminate_wq;
+
+ spinlock_t lock;
+ struct sio_tx *current_tx;
+ /*
+ * 'tx_cookie' is used for distinguishing between transactions from
+ * within tag ack/nack callbacks. Without it, we would have no way
+ * of knowing if the current transaction is the one the callback handler
+ * was installed for.
+ */
+ unsigned long tx_cookie;
+ int nperiod_acks;
+
+ /*
+ * We maintain a 'submitted' and 'issued' list mainly for interface
+ * correctness. Typical use of the driver (per channel) will be
+ * prepping, submitting and issuing a single cyclic transaction which
+ * will stay current until terminate_all is called.
+ */
+ struct list_head submitted;
+ struct list_head issued;
+
+ struct list_head to_free;
+};
+
+#define SIO_NTAGS 16
+
+typedef void (*sio_ack_callback)(struct sio_chan *, void *, bool);
+
+struct sio_data {
+ void __iomem *base;
+ struct dma_device dma;
+ struct device *dev;
+ struct apple_rtkit *rtk;
+ void *shmem;
+ struct sio_coproc_desc *shmem_desc_base;
+ unsigned long *desc_allocated;
+
+ struct sio_tagdata {
+ static_assert(sizeof(unsigned long) * 8 >= SIO_NTAGS);
+ unsigned long allocated;
+ int last_tag;
+
+ struct completion completions[SIO_NTAGS];
+ bool atomic[SIO_NTAGS];
+ bool acked[SIO_NTAGS];
+
+ sio_ack_callback ack_callback[SIO_NTAGS];
+ void *cookie[SIO_NTAGS];
+ } tags;
+
+ int nchannels;
+ struct sio_chan channels[];
+};
+
+struct sio_tx {
+ struct dma_async_tx_descriptor tx;
+ struct list_head node;
+ struct completion done;
+
+ bool terminated;
+ size_t period_len;
+ int nperiods;
+ int ninflight;
+ int next;
+
+ struct sio_coproc_desc *siodesc[];
+};
+
+static int sio_send_siomsg(struct sio_data *sio, u64 msg);
+static int sio_send_siomsg_atomic(struct sio_data *sio, u64 msg,
+ sio_ack_callback ack_callback,
+ void *cookie);
+static int sio_call(struct sio_data *sio, u64 msg);
+
+static struct sio_chan *to_sio_chan(struct dma_chan *chan)
+{
+ return container_of(chan, struct sio_chan, chan);
+}
+
+static struct sio_tx *to_sio_tx(struct dma_async_tx_descriptor *tx)
+{
+ return container_of(tx, struct sio_tx, tx);
+}
+
+static int sio_alloc_tag(struct sio_data *sio)
+{
+ struct sio_tagdata *tags = &sio->tags;
+ int tag, i;
+
+ /*
+ * Because tag number 0 is special, the usable tag range
+ * is 1...(SIO_NTAGS - 1). So, to pick the next usable tag,
+ * we do modulo (SIO_NTAGS - 1) *then* plus one.
+ */
+
+#define SIO_USABLE_TAGS (SIO_NTAGS - 1)
+ tag = (READ_ONCE(tags->last_tag) % SIO_USABLE_TAGS) + 1;
+
+ for (i = 0; i < SIO_USABLE_TAGS; i++) {
+ if (!test_and_set_bit(tag, &tags->allocated))
+ break;
+
+ tag = (tag % SIO_USABLE_TAGS) + 1;
+ }
+
+ WRITE_ONCE(tags->last_tag, tag);
+
+ if (i < SIO_USABLE_TAGS)
+ return tag;
+ else
+ return -EBUSY;
+#undef SIO_USABLE_TAGS
+}
+
+static void sio_free_tag(struct sio_data *sio, int tag)
+{
+ struct sio_tagdata *tags = &sio->tags;
+
+ if (WARN_ON(tag >= SIO_NTAGS))
+ return;
+
+ tags->atomic[tag] = false;
+ tags->ack_callback[tag] = NULL;
+
+ WARN_ON(!test_and_clear_bit(tag, &tags->allocated));
+}
+
+static void sio_set_tag_atomic(struct sio_data *sio, int tag,
+ sio_ack_callback ack_callback,
+ void *cookie)
+{
+ struct sio_tagdata *tags = &sio->tags;
+
+ tags->atomic[tag] = true;
+ tags->ack_callback[tag] = ack_callback;
+ tags->cookie[tag] = cookie;
+}
+
+struct sio_coproc_desc *sio_alloc_desc(struct sio_data *sio)
+{
+ int i;
+
+ for (i = 0; i < SIO_NO_DESC_SLOTS; i++)
+ if (!test_and_set_bit(i, sio->desc_allocated))
+ return sio->shmem_desc_base + i;
+
+ return NULL;
+}
+
+void sio_free_desc(struct sio_data *sio, struct sio_coproc_desc *desc)
+{
+ clear_bit(desc - sio->shmem_desc_base, sio->desc_allocated);
+}
+
+int sio_coproc_desc_slot(struct sio_data *sio, struct sio_coproc_desc *desc)
+{
+ return (desc - sio->shmem_desc_base) * 4;
+}
+
+static enum dma_transfer_direction sio_chan_direction(int channo)
+{
+ /* Channel directions are fixed based on channel number */
+ return (channo & 1) ? DMA_DEV_TO_MEM : DMA_MEM_TO_DEV;
+}
+
+static dma_cookie_t sio_tx_submit(struct dma_async_tx_descriptor *tx)
+{
+ struct sio_tx *siotx = to_sio_tx(tx);
+ struct sio_chan *siochan = to_sio_chan(tx->chan);
+ unsigned long flags;
+ dma_cookie_t cookie;
+
+ spin_lock_irqsave(&siochan->lock, flags);
+ cookie = dma_cookie_assign(tx);
+ list_add_tail(&siotx->node, &siochan->submitted);
+ spin_unlock_irqrestore(&siochan->lock, flags);
+
+ return cookie;
+}
+
+static int sio_tx_free(struct dma_async_tx_descriptor *tx)
+{
+ struct sio_data *sio = to_sio_chan(tx->chan)->host;
+ struct sio_tx *siotx = to_sio_tx(tx);
+ int i;
+
+ for (i = 0; i < siotx->nperiods; i++)
+ if (siotx->siodesc[i])
+ sio_free_desc(sio, siotx->siodesc[i]);
+ kfree(siotx);
+
+ return 0;
+}
+
+static struct dma_async_tx_descriptor *sio_prep_dma_cyclic(
+ struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,
+ size_t period_len, enum dma_transfer_direction direction,
+ unsigned long flags)
+{
+ struct sio_chan *siochan = to_sio_chan(chan);
+ struct sio_tx *siotx = NULL;
+ int i, nperiods = buf_len / period_len;
+
+ if (direction != sio_chan_direction(siochan->no))
+ return NULL;
+
+ siotx = kzalloc(struct_size(siotx, siodesc, nperiods), GFP_NOWAIT);
+ if (!siotx)
+ return NULL;
+
+ init_completion(&siotx->done);
+ dma_async_tx_descriptor_init(&siotx->tx, chan);
+ siotx->period_len = period_len;
+ siotx->nperiods = nperiods;
+
+ for (i = 0; i < nperiods; i++) {
+ struct sio_coproc_desc *d;
+
+ siotx->siodesc[i] = d = sio_alloc_desc(siochan->host);
+ if (!d) {
+ sio_tx_free(&siotx->tx);
+ return NULL;
+ }
+
+ d->flag = 1; // not sure what's up with this
+ d->iova = buf_addr + period_len * i;
+ d->size = period_len;
+ }
+ dma_wmb();
+
+ siotx->tx.tx_submit = sio_tx_submit;
+ siotx->tx.desc_free = sio_tx_free;
+
+ return &siotx->tx;
+}
+
+static enum dma_status sio_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
+ struct dma_tx_state *txstate)
+{
+ struct sio_chan *siochan = to_sio_chan(chan);
+ struct sio_tx *siotx;
+ enum dma_status ret;
+ unsigned long flags;
+ int periods_residue;
+ size_t residue;
+
+ ret = dma_cookie_status(chan, cookie, txstate);
+ if (ret == DMA_COMPLETE || !txstate)
+ return ret;
+
+ spin_lock_irqsave(&siochan->lock, flags);
+ siotx = siochan->current_tx;
+
+ if (siotx && siotx->tx.cookie == cookie) {
+ ret = DMA_IN_PROGRESS;
+ periods_residue = siotx->next - siotx->ninflight;
+ while (periods_residue < 0)
+ periods_residue += siotx->nperiods;
+ residue = (siotx->nperiods - periods_residue) * siotx->period_len;
+ } else {
+ ret = DMA_IN_PROGRESS;
+ residue = 0;
+ list_for_each_entry(siotx, &siochan->issued, node) {
+ if (siotx->tx.cookie == cookie) {
+ residue = siotx->period_len * siotx->nperiods;
+ break;
+ }
+ }
+ }
+ spin_unlock_irqrestore(&siochan->lock, flags);
+ dma_set_residue(txstate, residue);
+
+ return ret;
+}
+
+static bool sio_fill_in_locked(struct sio_chan *siochan);
+
+static void sio_handle_issue_ack(struct sio_chan *siochan, void *cookie, bool ok)
+{
+ unsigned long flags;
+ unsigned long tx_cookie = (unsigned long) cookie;
+ struct sio_tx *tx;
+
+ if (!ok) {
+ dev_err(siochan->host->dev, "nacked issue on chan %d\n", siochan->no);
+ return;
+ }
+
+ spin_lock_irqsave(&siochan->lock, flags);
+ if (!siochan->current_tx || tx_cookie != siochan->tx_cookie ||
+ siochan->current_tx->terminated)
+ goto out;
+
+ tx = siochan->current_tx;
+ tx->next = (tx->next + 1) % tx->nperiods;
+ tx->ninflight++;
+ sio_fill_in_locked(siochan);
+
+out:
+ spin_unlock_irqrestore(&siochan->lock, flags);
+}
+
+static bool sio_fill_in_locked(struct sio_chan *siochan)
+{
+ struct sio_data *sio = siochan->host;
+ struct sio_tx *tx = siochan->current_tx;
+ struct sio_coproc_desc *d = tx->siodesc[tx->next];
+ int ret;
+
+ if (tx->ninflight >= SIO_MAX_NINFLIGHT || tx->terminated)
+ return false;
+
+ ret = sio_send_siomsg_atomic(sio, FIELD_PREP(SIOMSG_EP, siochan->no) |
+ FIELD_PREP(SIOMSG_TYPE, MSG_ISSUE) |
+ FIELD_PREP(SIOMSG_DATA, sio_coproc_desc_slot(sio, d)),
+ sio_handle_issue_ack, (void *) siochan->tx_cookie);
+ if (ret < 0)
+ dev_err_ratelimited(sio->dev, "can't issue on chan %d ninflight %d: %d\n",
+ siochan->no, tx->ninflight, ret);
+ return true;
+}
+
+static void sio_update_current_tx_locked(struct sio_chan *siochan)
+{
+ struct sio_tx *tx;
+
+ if (!list_empty(&siochan->issued) && !siochan->current_tx) {
+ tx = list_first_entry(&siochan->issued, struct sio_tx, node);
+ list_del(&tx->node);
+
+ siochan->current_tx = tx;
+ sio_fill_in_locked(siochan);
+ }
+}
+
+static void sio_issue_pending(struct dma_chan *chan)
+{
+ struct sio_chan *siochan = to_sio_chan(chan);
+ unsigned long flags;
+
+ spin_lock_irqsave(&siochan->lock, flags);
+ list_splice_tail_init(&siochan->submitted, &siochan->issued);
+ sio_update_current_tx_locked(siochan);
+ spin_unlock_irqrestore(&siochan->lock, flags);
+}
+
+static int sio_terminate_all(struct dma_chan *chan)
+{
+ struct sio_chan *siochan = to_sio_chan(chan);
+ unsigned long flags;
+
+ spin_lock_irqsave(&siochan->lock, flags);
+ if (siochan->current_tx) {
+ siochan->current_tx->terminated = true;
+ schedule_work(&siochan->terminate_wq);
+ }
+ list_splice_tail_init(&siochan->submitted, &siochan->to_free);
+ list_splice_tail_init(&siochan->issued, &siochan->to_free);
+ spin_unlock_irqrestore(&siochan->lock, flags);
+
+ return 0;
+}
+
+static void sio_terminate_work(struct work_struct *wq)
+{
+ struct sio_chan *siochan = container_of(wq, struct sio_chan, terminate_wq);
+ struct sio_tx *tx, *_tx;
+ unsigned long flags;
+ LIST_HEAD(to_free);
+ int ret;
+
+ spin_lock_irqsave(&siochan->lock, flags);
+ tx = siochan->current_tx;
+ list_splice_tail_init(&siochan->to_free, &to_free);
+ spin_unlock_irqrestore(&siochan->lock, flags);
+
+ if (WARN_ON(!tx))
+ return;
+
+ ret = sio_call(siochan->host, FIELD_PREP(SIOMSG_EP, siochan->no) |
+ FIELD_PREP(SIOMSG_TYPE, MSG_TERMINATE));
+ if (ret < 0)
+ dev_err(siochan->host->dev, "terminate call on chan %d failed: %d\n",
+ siochan->no, ret);
+
+ ret = wait_for_completion_timeout(&tx->done, msecs_to_jiffies(500));
+ if (!ret)
+ dev_err(siochan->host->dev, "terminate descriptor wait timed out\n");
+
+ tasklet_kill(&siochan->tasklet);
+
+ spin_lock_irqsave(&siochan->lock, flags);
+ WARN_ON(siochan->current_tx != tx);
+ siochan->current_tx = NULL;
+ sio_update_current_tx_locked(siochan);
+ spin_unlock_irqrestore(&siochan->lock, flags);
+
+ sio_tx_free(&tx->tx);
+ list_for_each_entry_safe(tx, _tx, &to_free, node) {
+ list_del(&tx->node);
+ sio_tx_free(&tx->tx);
+ }
+}
+
+static void sio_synchronize(struct dma_chan *chan)
+{
+ struct sio_chan *siochan = to_sio_chan(chan);
+
+ flush_work(&siochan->terminate_wq);
+}
+
+static int sio_alloc_chan_resources(struct dma_chan *chan)
+{
+ struct sio_chan *siochan = to_sio_chan(chan);
+
+ dma_cookie_init(&siochan->chan);
+ return 0;
+}
+
+static void sio_free_chan_resources(struct dma_chan *chan)
+{
+ sio_terminate_all(chan);
+ sio_synchronize(chan);
+}
+
+static struct dma_chan *sio_dma_of_xlate(struct of_phandle_args *dma_spec,
+ struct of_dma *ofdma)
+{
+ struct sio_data *sio = (struct sio_data *) ofdma->of_dma_data;
+ unsigned int index = dma_spec->args[0];
+
+ if (dma_spec->args_count != 1 || index >= sio->nchannels)
+ return ERR_PTR(-EINVAL);
+
+ return dma_get_slave_channel(&sio->channels[index].chan);
+}
+
+static void sio_rtk_crashed(void *cookie)
+{
+ struct sio_data *sio = cookie;
+
+ dev_err(sio->dev, "SIO down (crashed)");
+}
+
+static void sio_process_report(struct sio_chan *siochan)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&siochan->lock, flags);
+ if (siochan->current_tx) {
+ struct sio_tx *tx = siochan->current_tx;
+
+ siochan->nperiod_acks++;
+ if (tx->ninflight)
+ tx->ninflight--;
+ if (!tx->terminated)
+ tasklet_schedule(&siochan->tasklet);
+ if (!sio_fill_in_locked(siochan) && !tx->ninflight)
+ complete(&tx->done);
+ }
+ spin_unlock_irqrestore(&siochan->lock, flags);
+}
+
+static void sio_recv_msg(void *cookie, u8 ep, u64 msg)
+{
+ struct sio_data *sio = cookie;
+ struct sio_tagdata *tags = &sio->tags;
+ u32 data;
+ u8 param, type, tag, sioep;
+
+ if (ep != EP_SIO)
+ goto unknown;
+
+ data = FIELD_GET(SIOMSG_DATA, msg);
+ param = FIELD_GET(SIOMSG_PARAM, msg);
+ type = FIELD_GET(SIOMSG_TYPE, msg);
+ tag = FIELD_GET(SIOMSG_TAG, msg);
+ sioep = FIELD_GET(SIOMSG_EP, msg);
+
+ switch (type) {
+ case MSG_STARTED:
+ dev_info(sio->dev, "SIO protocol v%u\n", data);
+ type = MSG_ACK; /* Pretend this is an ACK */
+ fallthrough;
+ case MSG_ACK:
+ case MSG_NACK:
+ if (WARN_ON(tag >= SIO_NTAGS))
+ break;
+
+ if (tags->atomic[tag]) {
+ sio_ack_callback callback = tags->ack_callback[tag];
+
+ if (callback && !WARN_ON(sioep >= sio->nchannels))
+ callback(&sio->channels[sioep],
+ tags->cookie[tag], type == MSG_ACK);
+ if (type == MSG_NACK)
+ dev_err(sio->dev, "got a NACK on channel %d\n", sioep);
+ sio_free_tag(sio, tag);
+ } else {
+ tags->acked[tag] = (type == MSG_ACK);
+ complete(&tags->completions[tag]);
+ }
+ break;
+
+ case MSG_REPORT:
+ if (WARN_ON(sioep >= sio->nchannels))
+ break;
+
+ sio_process_report(&sio->channels[sioep]);
+ break;
+
+ default:
+ goto unknown;
+ }
+ return;
+
+unknown:
+ dev_warn(sio->dev, "received unknown message: ep %x data %016llx\n",
+ ep, msg);
+}
+
+static int _sio_send_siomsg(struct sio_data *sio, u64 msg, bool atomic,
+ sio_ack_callback ack_callback, void *cookie)
+{
+ int tag, ret;
+
+ tag = sio_alloc_tag(sio);
+ if (tag < 0)
+ return tag;
+
+ if (atomic)
+ sio_set_tag_atomic(sio, tag, ack_callback, cookie);
+ else
+ reinit_completion(&sio->tags.completions[tag]);
+
+ msg &= ~SIOMSG_TAG;
+ msg |= FIELD_PREP(SIOMSG_TAG, tag);
+ ret = apple_rtkit_send_message(sio->rtk, EP_SIO, msg, NULL,
+ atomic);
+ if (ret < 0) {
+ sio_free_tag(sio, tag);
+ return ret;
+ }
+
+ return tag;
+}
+
+static int sio_send_siomsg(struct sio_data *sio, u64 msg)
+{
+ return _sio_send_siomsg(sio, msg, false, NULL, NULL);
+}
+
+static int sio_send_siomsg_atomic(struct sio_data *sio, u64 msg,
+ sio_ack_callback ack_callback,
+ void *cookie)
+{
+ return _sio_send_siomsg(sio, msg, true, ack_callback, cookie);
+}
+
+static int sio_call(struct sio_data *sio, u64 msg)
+{
+ int tag, ret;
+
+ tag = sio_send_siomsg(sio, msg);
+ if (tag < 0)
+ return tag;
+
+ ret = wait_for_completion_timeout(&sio->tags.completions[tag],
+ msecs_to_jiffies(SIO_CALL_TIMEOUT_MS));
+ if (!ret) {
+ dev_warn(sio->dev, "call %8x timed out\n", msg);
+ sio_free_tag(sio, tag);
+ return -ETIME;
+ }
+
+ ret = sio->tags.acked[tag];
+ sio_free_tag(sio, tag);
+
+ return ret;
+}
+
+static const struct apple_rtkit_ops sio_rtkit_ops = {
+ .crashed = sio_rtk_crashed,
+ .recv_message = sio_recv_msg,
+};
+
+static void sio_chan_tasklet(struct tasklet_struct *t)
+{
+ struct sio_chan *siochan = container_of(t, struct sio_chan, tasklet);
+ struct sio_tx *siotx;
+ struct dmaengine_desc_callback cb;
+ struct dmaengine_result tx_result;
+ unsigned long flags;
+ int nacks;
+
+ spin_lock_irqsave(&siochan->lock, flags);
+ siotx = siochan->current_tx;
+ nacks = siochan->nperiod_acks;
+ siochan->nperiod_acks = 0;
+ spin_unlock_irqrestore(&siochan->lock, flags);
+
+ if (!siotx || !nacks)
+ return;
+
+ tx_result.result = DMA_TRANS_NOERROR;
+ tx_result.residue = 0;
+
+ dmaengine_desc_get_callback(&siotx->tx, &cb);
+ while (nacks--)
+ dmaengine_desc_callback_invoke(&cb, &tx_result);
+}
+
+static int sio_device_config(struct dma_chan *chan,
+ struct dma_slave_config *config)
+{
+ struct sio_chan *siochan = to_sio_chan(chan);
+ struct sio_data *sio = siochan->host;
+ bool is_tx = sio_chan_direction(siochan->no) == DMA_MEM_TO_DEV;
+ struct sio_shmem_chan_config *cfg = sio->shmem;
+ int ret;
+
+ switch (is_tx ? config->dst_addr_width : config->src_addr_width) {
+ case DMA_SLAVE_BUSWIDTH_1_BYTE:
+ cfg->datashape = 0;
+ break;
+ case DMA_SLAVE_BUSWIDTH_2_BYTES:
+ cfg->datashape = 1;
+ break;
+ case DMA_SLAVE_BUSWIDTH_4_BYTES:
+ cfg->datashape = 2;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ cfg->fifo = 0x800;
+ cfg->limit = 0x800;
+ cfg->threshold = 0x800;
+ dma_wmb();
+
+ ret = sio_call(sio, FIELD_PREP(SIOMSG_TYPE, MSG_CONFIGURE) |
+ FIELD_PREP(SIOMSG_EP, siochan->no));
+
+ if (ret == 1)
+ ret = 0;
+ else if (ret == 0)
+ ret = -EINVAL;
+ return ret;
+}
+
+static int sio_alloc_shmem(struct sio_data *sio)
+{
+ dma_addr_t iova;
+ int err;
+
+ sio->shmem = dma_alloc_coherent(sio->dev, SIO_SHMEM_SIZE,
+ &iova, GFP_KERNEL);
+ if (!sio->shmem)
+ return -ENOMEM;
+
+ sio->shmem_desc_base = (struct sio_coproc_desc *) (sio->shmem + 56);
+ sio->desc_allocated = devm_kzalloc(sio->dev, SIO_NO_DESC_SLOTS / 32,
+ GFP_KERNEL);
+ if (!sio->desc_allocated)
+ return -ENOMEM;
+
+ err = sio_call(sio, FIELD_PREP(SIOMSG_TYPE, MSG_SETUP) |
+ FIELD_PREP(SIOMSG_PARAM, 1) |
+ FIELD_PREP(SIOMSG_DATA, iova >> 12));
+ if (err != 1) {
+ if (err == 0)
+ err = -EINVAL;
+ return err;
+ }
+
+ err = sio_call(sio, FIELD_PREP(SIOMSG_TYPE, MSG_SETUP) |
+ FIELD_PREP(SIOMSG_PARAM, 2) |
+ FIELD_PREP(SIOMSG_DATA, SIO_SHMEM_SIZE));
+ if (err != 1) {
+ if (err == 0)
+ err = -EINVAL;
+ return err;
+ }
+
+ return 0;
+}
+
+static int sio_send_dt_params(struct sio_data *sio)
+{
+ struct device_node *np = sio->dev->of_node;
+ const char *propname = "apple,sio-firmware-params";
+ int nparams, err, i;
+
+ nparams = of_property_count_u32_elems(np, propname);
+ if (nparams < 0) {
+ err = nparams;
+ goto badprop;
+ }
+
+ for (i = 0; i < nparams / 2; i++) {
+ u32 key, val;
+
+ err = of_property_read_u32_index(np, propname, 2 * i, &key);
+ if (err)
+ goto badprop;
+ err = of_property_read_u32_index(np, propname, 2 * i + 1, &val);
+ if (err)
+ goto badprop;
+
+ err = sio_call(sio, FIELD_PREP(SIOMSG_TYPE, MSG_SETUP) |
+ FIELD_PREP(SIOMSG_PARAM, key & 0xff) |
+ FIELD_PREP(SIOMSG_EP, key >> 8) |
+ FIELD_PREP(SIOMSG_DATA, val));
+ if (err < 1) {
+ if (err == 0)
+ err = -ENXIO;
+ return dev_err_probe(sio->dev, err, "sending SIO parameter %#x value %#x\n",
+ key, val);
+ }
+ }
+
+ return 0;
+
+badprop:
+ return dev_err_probe(sio->dev, err, "failed to read '%s'\n", propname);
+}
+
+static int sio_probe(struct platform_device *pdev)
+{
+ struct device_node *np = pdev->dev.of_node;
+ struct sio_data *sio;
+ struct dma_device *dma;
+ int nchannels;
+ int err, i;
+
+ err = of_property_read_u32(np, "dma-channels", &nchannels);
+ if (err || nchannels > NCHANNELS_MAX)
+ return dev_err_probe(&pdev->dev, -EINVAL,
+ "missing or invalid dma-channels property\n");
+
+ sio = devm_kzalloc(&pdev->dev, struct_size(sio, channels, nchannels), GFP_KERNEL);
+ if (!sio)
+ return -ENOMEM;
+
+ platform_set_drvdata(pdev, sio);
+ sio->dev = &pdev->dev;
+ sio->nchannels = nchannels;
+
+ sio->base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(sio->base))
+ return PTR_ERR(sio->base);
+
+ sio->rtk = devm_apple_rtkit_init(&pdev->dev, sio, NULL, 0, &sio_rtkit_ops);
+ if (IS_ERR(sio->rtk))
+ return dev_err_probe(&pdev->dev, PTR_ERR(sio->rtk),
+ "couldn't initialize rtkit\n");
+ for (i = 1; i < SIO_NTAGS; i++)
+ init_completion(&sio->tags.completions[i]);
+
+ dma = &sio->dma;
+ dma_cap_set(DMA_PRIVATE, dma->cap_mask);
+ dma_cap_set(DMA_CYCLIC, dma->cap_mask);
+
+ dma->dev = &pdev->dev;
+ dma->device_alloc_chan_resources = sio_alloc_chan_resources;
+ dma->device_free_chan_resources = sio_free_chan_resources;
+ dma->device_tx_status = sio_tx_status;
+ dma->device_issue_pending = sio_issue_pending;
+ dma->device_terminate_all = sio_terminate_all;
+ dma->device_synchronize = sio_synchronize;
+ dma->device_prep_dma_cyclic = sio_prep_dma_cyclic;
+ dma->device_config = sio_device_config;
+
+ dma->directions = BIT(DMA_MEM_TO_DEV);
+ dma->residue_granularity = DMA_RESIDUE_GRANULARITY_SEGMENT;
+ dma->dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
+ BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
+ BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
+
+ INIT_LIST_HEAD(&dma->channels);
+ for (i = 0; i < nchannels; i++) {
+ struct sio_chan *siochan = &sio->channels[i];
+
+ siochan->host = sio;
+ siochan->no = i;
+ siochan->chan.device = &sio->dma;
+ spin_lock_init(&siochan->lock);
+ INIT_LIST_HEAD(&siochan->submitted);
+ INIT_LIST_HEAD(&siochan->issued);
+ INIT_LIST_HEAD(&siochan->to_free);
+ list_add_tail(&siochan->chan.device_node, &dma->channels);
+ tasklet_setup(&siochan->tasklet, sio_chan_tasklet);
+ INIT_WORK(&siochan->terminate_wq, sio_terminate_work);
+ }
+
+ writel(CPU_CONTROL_RUN, sio->base + REG_CPU_CONTROL);
+
+ err = apple_rtkit_boot(sio->rtk);
+ if (err)
+ return dev_err_probe(&pdev->dev, err, "SIO did not boot\n");
+
+ err = apple_rtkit_start_ep(sio->rtk, EP_SIO);
+ if (err)
+ return dev_err_probe(&pdev->dev, err, "starting SIO endpoint\n");
+
+ err = sio_call(sio, FIELD_PREP(SIOMSG_TYPE, MSG_START));
+ if (err < 1) {
+ if (err == 0)
+ err = -ENXIO;
+ return dev_err_probe(&pdev->dev, err, "starting SIO service\n");
+ }
+
+ err = sio_send_dt_params(sio);
+ if (err < 0)
+ return dev_err_probe(&pdev->dev, err, "failed to send boot-up parameters\n");
+
+ err = sio_alloc_shmem(sio);
+ if (err < 0)
+ return err;
+
+ err = dma_async_device_register(&sio->dma);
+ if (err)
+ return dev_err_probe(&pdev->dev, err, "failed to register DMA device\n");
+
+ err = of_dma_controller_register(pdev->dev.of_node, sio_dma_of_xlate, sio);
+ if (err) {
+ dma_async_device_unregister(&sio->dma);
+ return dev_err_probe(&pdev->dev, err, "failed to register with OF\n");
+ }
+
+ return 0;
+}
+
+static int sio_remove(struct platform_device *pdev)
+{
+ struct sio_data *sio = platform_get_drvdata(pdev);
+
+ of_dma_controller_free(pdev->dev.of_node);
+ dma_async_device_unregister(&sio->dma);
+ return 0;
+}
+
+static const struct of_device_id sio_of_match[] = {
+ { .compatible = "apple,sio", },
+ { }
+};
+MODULE_DEVICE_TABLE(of, sio_of_match);
+
+static struct platform_driver apple_sio_driver = {
+ .driver = {
+ .name = "apple-sio",
+ .of_match_table = sio_of_match,
+ },
+ .probe = sio_probe,
+ .remove = sio_remove,
+};
+module_platform_driver(apple_sio_driver);
+
+MODULE_AUTHOR("Martin Povišer <povik+lin@cutebit.org>");
+MODULE_DESCRIPTION("Driver for SIO coprocessor on Apple SoCs");
+MODULE_LICENSE("Dual MIT/GPL");