diff options
Diffstat (limited to 'drivers/dma/apple-admac.c')
| -rw-r--r-- | drivers/dma/apple-admac.c | 957 |
1 files changed, 957 insertions, 0 deletions
diff --git a/drivers/dma/apple-admac.c b/drivers/dma/apple-admac.c new file mode 100644 index 000000000..4cf8da77b --- /dev/null +++ b/drivers/dma/apple-admac.c @@ -0,0 +1,957 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Driver for Audio DMA Controller (ADMAC) on t8103 (M1) and other Apple chips + * + * Copyright (C) The Asahi Linux Contributors + */ + +#include <linux/bits.h> +#include <linux/bitfield.h> +#include <linux/device.h> +#include <linux/init.h> +#include <linux/module.h> +#include <linux/of_device.h> +#include <linux/of_dma.h> +#include <linux/reset.h> +#include <linux/spinlock.h> +#include <linux/interrupt.h> + +#include "dmaengine.h" + +#define NCHANNELS_MAX 64 +#define IRQ_NOUTPUTS 4 + +/* + * For allocation purposes we split the cache + * memory into blocks of fixed size (given in bytes). + */ +#define SRAM_BLOCK 2048 + +#define RING_WRITE_SLOT GENMASK(1, 0) +#define RING_READ_SLOT GENMASK(5, 4) +#define RING_FULL BIT(9) +#define RING_EMPTY BIT(8) +#define RING_ERR BIT(10) + +#define STATUS_DESC_DONE BIT(0) +#define STATUS_ERR BIT(6) + +#define FLAG_DESC_NOTIFY BIT(16) + +#define REG_TX_START 0x0000 +#define REG_TX_STOP 0x0004 +#define REG_RX_START 0x0008 +#define REG_RX_STOP 0x000c +#define REG_IMPRINT 0x0090 +#define REG_TX_SRAM_SIZE 0x0094 +#define REG_RX_SRAM_SIZE 0x0098 + +#define REG_CHAN_CTL(ch) (0x8000 + (ch) * 0x200) +#define REG_CHAN_CTL_RST_RINGS BIT(0) + +#define REG_DESC_RING(ch) (0x8070 + (ch) * 0x200) +#define REG_REPORT_RING(ch) (0x8074 + (ch) * 0x200) + +#define REG_RESIDUE(ch) (0x8064 + (ch) * 0x200) + +#define REG_BUS_WIDTH(ch) (0x8040 + (ch) * 0x200) + +#define BUS_WIDTH_8BIT 0x00 +#define BUS_WIDTH_16BIT 0x01 +#define BUS_WIDTH_32BIT 0x02 +#define BUS_WIDTH_FRAME_2_WORDS 0x10 +#define BUS_WIDTH_FRAME_4_WORDS 0x20 + +#define REG_CHAN_SRAM_CARVEOUT(ch) (0x8050 + (ch) * 0x200) +#define CHAN_SRAM_CARVEOUT_SIZE GENMASK(31, 16) +#define CHAN_SRAM_CARVEOUT_BASE GENMASK(15, 0) + +#define REG_CHAN_FIFOCTL(ch) (0x8054 + (ch) * 0x200) +#define CHAN_FIFOCTL_LIMIT GENMASK(31, 16) +#define CHAN_FIFOCTL_THRESHOLD GENMASK(15, 0) + +#define REG_DESC_WRITE(ch) (0x10000 + ((ch) / 2) * 0x4 + ((ch) & 1) * 0x4000) +#define REG_REPORT_READ(ch) (0x10100 + ((ch) / 2) * 0x4 + ((ch) & 1) * 0x4000) + +#define REG_TX_INTSTATE(idx) (0x0030 + (idx) * 4) +#define REG_RX_INTSTATE(idx) (0x0040 + (idx) * 4) +#define REG_GLOBAL_INTSTATE(idx) (0x0050 + (idx) * 4) +#define REG_CHAN_INTSTATUS(ch, idx) (0x8010 + (ch) * 0x200 + (idx) * 4) +#define REG_CHAN_INTMASK(ch, idx) (0x8020 + (ch) * 0x200 + (idx) * 4) + +struct admac_data; +struct admac_tx; + +struct admac_chan { + unsigned int no; + struct admac_data *host; + struct dma_chan chan; + struct tasklet_struct tasklet; + + u32 carveout; + + spinlock_t lock; + struct admac_tx *current_tx; + 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; +}; + +struct admac_sram { + u32 size; + /* + * SRAM_CARVEOUT has 16-bit fields, so the SRAM cannot be larger than + * 64K and a 32-bit bitfield over 2K blocks covers it. + */ + u32 allocated; +}; + +struct admac_data { + struct dma_device dma; + struct device *dev; + __iomem void *base; + struct reset_control *rstc; + + struct mutex cache_alloc_lock; + struct admac_sram txcache, rxcache; + + int irq; + int irq_index; + int nchannels; + struct admac_chan channels[]; +}; + +struct admac_tx { + struct dma_async_tx_descriptor tx; + bool cyclic; + dma_addr_t buf_addr; + dma_addr_t buf_end; + size_t buf_len; + size_t period_len; + + size_t submitted_pos; + size_t reclaimed_pos; + + struct list_head node; +}; + +static int admac_alloc_sram_carveout(struct admac_data *ad, + enum dma_transfer_direction dir, + u32 *out) +{ + struct admac_sram *sram; + int i, ret = 0, nblocks; + + if (dir == DMA_MEM_TO_DEV) + sram = &ad->txcache; + else + sram = &ad->rxcache; + + mutex_lock(&ad->cache_alloc_lock); + + nblocks = sram->size / SRAM_BLOCK; + for (i = 0; i < nblocks; i++) + if (!(sram->allocated & BIT(i))) + break; + + if (i < nblocks) { + *out = FIELD_PREP(CHAN_SRAM_CARVEOUT_BASE, i * SRAM_BLOCK) | + FIELD_PREP(CHAN_SRAM_CARVEOUT_SIZE, SRAM_BLOCK); + sram->allocated |= BIT(i); + } else { + ret = -EBUSY; + } + + mutex_unlock(&ad->cache_alloc_lock); + + return ret; +} + +static void admac_free_sram_carveout(struct admac_data *ad, + enum dma_transfer_direction dir, + u32 carveout) +{ + struct admac_sram *sram; + u32 base = FIELD_GET(CHAN_SRAM_CARVEOUT_BASE, carveout); + int i; + + if (dir == DMA_MEM_TO_DEV) + sram = &ad->txcache; + else + sram = &ad->rxcache; + + if (WARN_ON(base >= sram->size)) + return; + + mutex_lock(&ad->cache_alloc_lock); + i = base / SRAM_BLOCK; + sram->allocated &= ~BIT(i); + mutex_unlock(&ad->cache_alloc_lock); +} + +static void admac_modify(struct admac_data *ad, int reg, u32 mask, u32 val) +{ + void __iomem *addr = ad->base + reg; + u32 curr = readl_relaxed(addr); + + writel_relaxed((curr & ~mask) | (val & mask), addr); +} + +static struct admac_chan *to_admac_chan(struct dma_chan *chan) +{ + return container_of(chan, struct admac_chan, chan); +} + +static struct admac_tx *to_admac_tx(struct dma_async_tx_descriptor *tx) +{ + return container_of(tx, struct admac_tx, tx); +} + +static enum dma_transfer_direction admac_chan_direction(int channo) +{ + /* Channel directions are hardwired */ + return (channo & 1) ? DMA_DEV_TO_MEM : DMA_MEM_TO_DEV; +} + +static dma_cookie_t admac_tx_submit(struct dma_async_tx_descriptor *tx) +{ + struct admac_tx *adtx = to_admac_tx(tx); + struct admac_chan *adchan = to_admac_chan(tx->chan); + unsigned long flags; + dma_cookie_t cookie; + + spin_lock_irqsave(&adchan->lock, flags); + cookie = dma_cookie_assign(tx); + list_add_tail(&adtx->node, &adchan->submitted); + spin_unlock_irqrestore(&adchan->lock, flags); + + return cookie; +} + +static int admac_desc_free(struct dma_async_tx_descriptor *tx) +{ + kfree(to_admac_tx(tx)); + + return 0; +} + +static struct dma_async_tx_descriptor *admac_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 admac_chan *adchan = container_of(chan, struct admac_chan, chan); + struct admac_tx *adtx; + + if (direction != admac_chan_direction(adchan->no)) + return NULL; + + adtx = kzalloc(sizeof(*adtx), GFP_NOWAIT); + if (!adtx) + return NULL; + + adtx->cyclic = true; + + adtx->buf_addr = buf_addr; + adtx->buf_len = buf_len; + adtx->buf_end = buf_addr + buf_len; + adtx->period_len = period_len; + + adtx->submitted_pos = 0; + adtx->reclaimed_pos = 0; + + dma_async_tx_descriptor_init(&adtx->tx, chan); + adtx->tx.tx_submit = admac_tx_submit; + adtx->tx.desc_free = admac_desc_free; + + return &adtx->tx; +} + +/* + * Write one hardware descriptor for a dmaengine cyclic transaction. + */ +static void admac_cyclic_write_one_desc(struct admac_data *ad, int channo, + struct admac_tx *tx) +{ + dma_addr_t addr; + + addr = tx->buf_addr + (tx->submitted_pos % tx->buf_len); + + /* If happens means we have buggy code */ + WARN_ON_ONCE(addr + tx->period_len > tx->buf_end); + + dev_dbg(ad->dev, "ch%d descriptor: addr=0x%pad len=0x%zx flags=0x%lx\n", + channo, &addr, tx->period_len, FLAG_DESC_NOTIFY); + + writel_relaxed(lower_32_bits(addr), ad->base + REG_DESC_WRITE(channo)); + writel_relaxed(upper_32_bits(addr), ad->base + REG_DESC_WRITE(channo)); + writel_relaxed(tx->period_len, ad->base + REG_DESC_WRITE(channo)); + writel_relaxed(FLAG_DESC_NOTIFY, ad->base + REG_DESC_WRITE(channo)); + + tx->submitted_pos += tx->period_len; + tx->submitted_pos %= 2 * tx->buf_len; +} + +/* + * Write all the hardware descriptors for a dmaengine cyclic + * transaction there is space for. + */ +static void admac_cyclic_write_desc(struct admac_data *ad, int channo, + struct admac_tx *tx) +{ + int i; + + for (i = 0; i < 4; i++) { + if (readl_relaxed(ad->base + REG_DESC_RING(channo)) & RING_FULL) + break; + admac_cyclic_write_one_desc(ad, channo, tx); + } +} + +static int admac_ring_noccupied_slots(int ringval) +{ + int wrslot = FIELD_GET(RING_WRITE_SLOT, ringval); + int rdslot = FIELD_GET(RING_READ_SLOT, ringval); + + if (wrslot != rdslot) { + return (wrslot + 4 - rdslot) % 4; + } else { + WARN_ON((ringval & (RING_FULL | RING_EMPTY)) == 0); + + if (ringval & RING_FULL) + return 4; + else + return 0; + } +} + +/* + * Read from hardware the residue of a cyclic dmaengine transaction. + */ +static u32 admac_cyclic_read_residue(struct admac_data *ad, int channo, + struct admac_tx *adtx) +{ + u32 ring1, ring2; + u32 residue1, residue2; + int nreports; + size_t pos; + + ring1 = readl_relaxed(ad->base + REG_REPORT_RING(channo)); + residue1 = readl_relaxed(ad->base + REG_RESIDUE(channo)); + ring2 = readl_relaxed(ad->base + REG_REPORT_RING(channo)); + residue2 = readl_relaxed(ad->base + REG_RESIDUE(channo)); + + if (residue2 > residue1) { + /* + * Controller must have loaded next descriptor between + * the two residue reads + */ + nreports = admac_ring_noccupied_slots(ring1) + 1; + } else { + /* No descriptor load between the two reads, ring2 is safe to use */ + nreports = admac_ring_noccupied_slots(ring2); + } + + pos = adtx->reclaimed_pos + adtx->period_len * (nreports + 1) - residue2; + + return adtx->buf_len - pos % adtx->buf_len; +} + +static enum dma_status admac_tx_status(struct dma_chan *chan, dma_cookie_t cookie, + struct dma_tx_state *txstate) +{ + struct admac_chan *adchan = to_admac_chan(chan); + struct admac_data *ad = adchan->host; + struct admac_tx *adtx; + + enum dma_status ret; + size_t residue; + unsigned long flags; + + ret = dma_cookie_status(chan, cookie, txstate); + if (ret == DMA_COMPLETE || !txstate) + return ret; + + spin_lock_irqsave(&adchan->lock, flags); + adtx = adchan->current_tx; + + if (adtx && adtx->tx.cookie == cookie) { + ret = DMA_IN_PROGRESS; + residue = admac_cyclic_read_residue(ad, adchan->no, adtx); + } else { + ret = DMA_IN_PROGRESS; + residue = 0; + list_for_each_entry(adtx, &adchan->issued, node) { + if (adtx->tx.cookie == cookie) { + residue = adtx->buf_len; + break; + } + } + } + spin_unlock_irqrestore(&adchan->lock, flags); + + dma_set_residue(txstate, residue); + return ret; +} + +static void admac_start_chan(struct admac_chan *adchan) +{ + struct admac_data *ad = adchan->host; + u32 startbit = 1 << (adchan->no / 2); + + writel_relaxed(STATUS_DESC_DONE | STATUS_ERR, + ad->base + REG_CHAN_INTSTATUS(adchan->no, ad->irq_index)); + writel_relaxed(STATUS_DESC_DONE | STATUS_ERR, + ad->base + REG_CHAN_INTMASK(adchan->no, ad->irq_index)); + + switch (admac_chan_direction(adchan->no)) { + case DMA_MEM_TO_DEV: + writel_relaxed(startbit, ad->base + REG_TX_START); + break; + case DMA_DEV_TO_MEM: + writel_relaxed(startbit, ad->base + REG_RX_START); + break; + default: + break; + } + dev_dbg(adchan->host->dev, "ch%d start\n", adchan->no); +} + +static void admac_stop_chan(struct admac_chan *adchan) +{ + struct admac_data *ad = adchan->host; + u32 stopbit = 1 << (adchan->no / 2); + + switch (admac_chan_direction(adchan->no)) { + case DMA_MEM_TO_DEV: + writel_relaxed(stopbit, ad->base + REG_TX_STOP); + break; + case DMA_DEV_TO_MEM: + writel_relaxed(stopbit, ad->base + REG_RX_STOP); + break; + default: + break; + } + dev_dbg(adchan->host->dev, "ch%d stop\n", adchan->no); +} + +static void admac_reset_rings(struct admac_chan *adchan) +{ + struct admac_data *ad = adchan->host; + + writel_relaxed(REG_CHAN_CTL_RST_RINGS, + ad->base + REG_CHAN_CTL(adchan->no)); + writel_relaxed(0, ad->base + REG_CHAN_CTL(adchan->no)); +} + +static void admac_start_current_tx(struct admac_chan *adchan) +{ + struct admac_data *ad = adchan->host; + int ch = adchan->no; + + admac_reset_rings(adchan); + writel_relaxed(0, ad->base + REG_CHAN_CTL(ch)); + + admac_cyclic_write_one_desc(ad, ch, adchan->current_tx); + admac_start_chan(adchan); + admac_cyclic_write_desc(ad, ch, adchan->current_tx); +} + +static void admac_issue_pending(struct dma_chan *chan) +{ + struct admac_chan *adchan = to_admac_chan(chan); + struct admac_tx *tx; + unsigned long flags; + + spin_lock_irqsave(&adchan->lock, flags); + list_splice_tail_init(&adchan->submitted, &adchan->issued); + if (!list_empty(&adchan->issued) && !adchan->current_tx) { + tx = list_first_entry(&adchan->issued, struct admac_tx, node); + list_del(&tx->node); + + adchan->current_tx = tx; + adchan->nperiod_acks = 0; + admac_start_current_tx(adchan); + } + spin_unlock_irqrestore(&adchan->lock, flags); +} + +static int admac_pause(struct dma_chan *chan) +{ + struct admac_chan *adchan = to_admac_chan(chan); + + admac_stop_chan(adchan); + + return 0; +} + +static int admac_resume(struct dma_chan *chan) +{ + struct admac_chan *adchan = to_admac_chan(chan); + + admac_start_chan(adchan); + + return 0; +} + +static int admac_terminate_all(struct dma_chan *chan) +{ + struct admac_chan *adchan = to_admac_chan(chan); + unsigned long flags; + + spin_lock_irqsave(&adchan->lock, flags); + admac_stop_chan(adchan); + admac_reset_rings(adchan); + + if (adchan->current_tx) { + list_add_tail(&adchan->current_tx->node, &adchan->to_free); + adchan->current_tx = NULL; + } + /* + * Descriptors can only be freed after the tasklet + * has been killed (in admac_synchronize). + */ + list_splice_tail_init(&adchan->submitted, &adchan->to_free); + list_splice_tail_init(&adchan->issued, &adchan->to_free); + spin_unlock_irqrestore(&adchan->lock, flags); + + return 0; +} + +static void admac_synchronize(struct dma_chan *chan) +{ + struct admac_chan *adchan = to_admac_chan(chan); + struct admac_tx *adtx, *_adtx; + unsigned long flags; + LIST_HEAD(head); + + spin_lock_irqsave(&adchan->lock, flags); + list_splice_tail_init(&adchan->to_free, &head); + spin_unlock_irqrestore(&adchan->lock, flags); + + tasklet_kill(&adchan->tasklet); + + list_for_each_entry_safe(adtx, _adtx, &head, node) { + list_del(&adtx->node); + admac_desc_free(&adtx->tx); + } +} + +static int admac_alloc_chan_resources(struct dma_chan *chan) +{ + struct admac_chan *adchan = to_admac_chan(chan); + struct admac_data *ad = adchan->host; + int ret; + + dma_cookie_init(&adchan->chan); + ret = admac_alloc_sram_carveout(ad, admac_chan_direction(adchan->no), + &adchan->carveout); + if (ret < 0) + return ret; + + writel_relaxed(adchan->carveout, + ad->base + REG_CHAN_SRAM_CARVEOUT(adchan->no)); + return 0; +} + +static void admac_free_chan_resources(struct dma_chan *chan) +{ + struct admac_chan *adchan = to_admac_chan(chan); + + admac_terminate_all(chan); + admac_synchronize(chan); + admac_free_sram_carveout(adchan->host, admac_chan_direction(adchan->no), + adchan->carveout); +} + +static struct dma_chan *admac_dma_of_xlate(struct of_phandle_args *dma_spec, + struct of_dma *ofdma) +{ + struct admac_data *ad = (struct admac_data *) ofdma->of_dma_data; + unsigned int index; + + if (dma_spec->args_count != 1) + return NULL; + + index = dma_spec->args[0]; + + if (index >= ad->nchannels) { + dev_err(ad->dev, "channel index %u out of bounds\n", index); + return NULL; + } + + return dma_get_slave_channel(&ad->channels[index].chan); +} + +static int admac_drain_reports(struct admac_data *ad, int channo) +{ + int count; + + for (count = 0; count < 4; count++) { + u32 countval_hi, countval_lo, unk1, flags; + + if (readl_relaxed(ad->base + REG_REPORT_RING(channo)) & RING_EMPTY) + break; + + countval_lo = readl_relaxed(ad->base + REG_REPORT_READ(channo)); + countval_hi = readl_relaxed(ad->base + REG_REPORT_READ(channo)); + unk1 = readl_relaxed(ad->base + REG_REPORT_READ(channo)); + flags = readl_relaxed(ad->base + REG_REPORT_READ(channo)); + + dev_dbg(ad->dev, "ch%d report: countval=0x%llx unk1=0x%x flags=0x%x\n", + channo, ((u64) countval_hi) << 32 | countval_lo, unk1, flags); + } + + return count; +} + +static void admac_handle_status_err(struct admac_data *ad, int channo) +{ + bool handled = false; + + if (readl_relaxed(ad->base + REG_DESC_RING(channo)) & RING_ERR) { + writel_relaxed(RING_ERR, ad->base + REG_DESC_RING(channo)); + dev_err_ratelimited(ad->dev, "ch%d descriptor ring error\n", channo); + handled = true; + } + + if (readl_relaxed(ad->base + REG_REPORT_RING(channo)) & RING_ERR) { + writel_relaxed(RING_ERR, ad->base + REG_REPORT_RING(channo)); + dev_err_ratelimited(ad->dev, "ch%d report ring error\n", channo); + handled = true; + } + + if (unlikely(!handled)) { + dev_err(ad->dev, "ch%d unknown error, masking errors as cause of IRQs\n", channo); + admac_modify(ad, REG_CHAN_INTMASK(channo, ad->irq_index), + STATUS_ERR, 0); + } +} + +static void admac_handle_status_desc_done(struct admac_data *ad, int channo) +{ + struct admac_chan *adchan = &ad->channels[channo]; + unsigned long flags; + int nreports; + + writel_relaxed(STATUS_DESC_DONE, + ad->base + REG_CHAN_INTSTATUS(channo, ad->irq_index)); + + spin_lock_irqsave(&adchan->lock, flags); + nreports = admac_drain_reports(ad, channo); + + if (adchan->current_tx) { + struct admac_tx *tx = adchan->current_tx; + + adchan->nperiod_acks += nreports; + tx->reclaimed_pos += nreports * tx->period_len; + tx->reclaimed_pos %= 2 * tx->buf_len; + + admac_cyclic_write_desc(ad, channo, tx); + tasklet_schedule(&adchan->tasklet); + } + spin_unlock_irqrestore(&adchan->lock, flags); +} + +static void admac_handle_chan_int(struct admac_data *ad, int no) +{ + u32 cause = readl_relaxed(ad->base + REG_CHAN_INTSTATUS(no, ad->irq_index)); + + if (cause & STATUS_ERR) + admac_handle_status_err(ad, no); + + if (cause & STATUS_DESC_DONE) + admac_handle_status_desc_done(ad, no); +} + +static irqreturn_t admac_interrupt(int irq, void *devid) +{ + struct admac_data *ad = devid; + u32 rx_intstate, tx_intstate, global_intstate; + int i; + + rx_intstate = readl_relaxed(ad->base + REG_RX_INTSTATE(ad->irq_index)); + tx_intstate = readl_relaxed(ad->base + REG_TX_INTSTATE(ad->irq_index)); + global_intstate = readl_relaxed(ad->base + REG_GLOBAL_INTSTATE(ad->irq_index)); + + if (!tx_intstate && !rx_intstate && !global_intstate) + return IRQ_NONE; + + for (i = 0; i < ad->nchannels; i += 2) { + if (tx_intstate & 1) + admac_handle_chan_int(ad, i); + tx_intstate >>= 1; + } + + for (i = 1; i < ad->nchannels; i += 2) { + if (rx_intstate & 1) + admac_handle_chan_int(ad, i); + rx_intstate >>= 1; + } + + if (global_intstate) { + dev_warn(ad->dev, "clearing unknown global interrupt flag: %x\n", + global_intstate); + writel_relaxed(~(u32) 0, ad->base + REG_GLOBAL_INTSTATE(ad->irq_index)); + } + + return IRQ_HANDLED; +} + +static void admac_chan_tasklet(struct tasklet_struct *t) +{ + struct admac_chan *adchan = from_tasklet(adchan, t, tasklet); + struct admac_tx *adtx; + struct dmaengine_desc_callback cb; + struct dmaengine_result tx_result; + int nacks; + + spin_lock_irq(&adchan->lock); + adtx = adchan->current_tx; + nacks = adchan->nperiod_acks; + adchan->nperiod_acks = 0; + spin_unlock_irq(&adchan->lock); + + if (!adtx || !nacks) + return; + + tx_result.result = DMA_TRANS_NOERROR; + tx_result.residue = 0; + + dmaengine_desc_get_callback(&adtx->tx, &cb); + while (nacks--) + dmaengine_desc_callback_invoke(&cb, &tx_result); +} + +static int admac_device_config(struct dma_chan *chan, + struct dma_slave_config *config) +{ + struct admac_chan *adchan = to_admac_chan(chan); + struct admac_data *ad = adchan->host; + bool is_tx = admac_chan_direction(adchan->no) == DMA_MEM_TO_DEV; + int wordsize = 0; + u32 bus_width = 0; + + switch (is_tx ? config->dst_addr_width : config->src_addr_width) { + case DMA_SLAVE_BUSWIDTH_1_BYTE: + wordsize = 1; + bus_width |= BUS_WIDTH_8BIT; + break; + case DMA_SLAVE_BUSWIDTH_2_BYTES: + wordsize = 2; + bus_width |= BUS_WIDTH_16BIT; + break; + case DMA_SLAVE_BUSWIDTH_4_BYTES: + wordsize = 4; + bus_width |= BUS_WIDTH_32BIT; + break; + default: + return -EINVAL; + } + + /* + * We take port_window_size to be the number of words in a frame. + * + * The controller has some means of out-of-band signalling, to the peripheral, + * of words position in a frame. That's where the importance of this control + * comes from. + */ + switch (is_tx ? config->dst_port_window_size : config->src_port_window_size) { + case 0 ... 1: + break; + case 2: + bus_width |= BUS_WIDTH_FRAME_2_WORDS; + break; + case 4: + bus_width |= BUS_WIDTH_FRAME_4_WORDS; + break; + default: + return -EINVAL; + } + + writel_relaxed(bus_width, ad->base + REG_BUS_WIDTH(adchan->no)); + + /* + * By FIFOCTL_LIMIT we seem to set the maximal number of bytes allowed to be + * held in controller's per-channel FIFO. Transfers seem to be triggered + * around the time FIFO occupancy touches FIFOCTL_THRESHOLD. + * + * The numbers we set are more or less arbitrary. + */ + writel_relaxed(FIELD_PREP(CHAN_FIFOCTL_LIMIT, 0x30 * wordsize) + | FIELD_PREP(CHAN_FIFOCTL_THRESHOLD, 0x18 * wordsize), + ad->base + REG_CHAN_FIFOCTL(adchan->no)); + + return 0; +} + +static int admac_probe(struct platform_device *pdev) +{ + struct device_node *np = pdev->dev.of_node; + struct admac_data *ad; + struct dma_device *dma; + int nchannels; + int err, irq, i; + + err = of_property_read_u32(np, "dma-channels", &nchannels); + if (err || nchannels > NCHANNELS_MAX) { + dev_err(&pdev->dev, "missing or invalid dma-channels property\n"); + return -EINVAL; + } + + ad = devm_kzalloc(&pdev->dev, struct_size(ad, channels, nchannels), GFP_KERNEL); + if (!ad) + return -ENOMEM; + + platform_set_drvdata(pdev, ad); + ad->dev = &pdev->dev; + ad->nchannels = nchannels; + mutex_init(&ad->cache_alloc_lock); + + /* + * The controller has 4 IRQ outputs. Try them all until + * we find one we can use. + */ + for (i = 0; i < IRQ_NOUTPUTS; i++) { + irq = platform_get_irq_optional(pdev, i); + if (irq >= 0) { + ad->irq_index = i; + break; + } + } + + if (irq < 0) + return dev_err_probe(&pdev->dev, irq, "no usable interrupt\n"); + ad->irq = irq; + + ad->base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(ad->base)) + return dev_err_probe(&pdev->dev, PTR_ERR(ad->base), + "unable to obtain MMIO resource\n"); + + ad->rstc = devm_reset_control_get_optional_shared(&pdev->dev, NULL); + if (IS_ERR(ad->rstc)) + return PTR_ERR(ad->rstc); + + dma = &ad->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 = admac_alloc_chan_resources; + dma->device_free_chan_resources = admac_free_chan_resources; + dma->device_tx_status = admac_tx_status; + dma->device_issue_pending = admac_issue_pending; + dma->device_terminate_all = admac_terminate_all; + dma->device_synchronize = admac_synchronize; + dma->device_prep_dma_cyclic = admac_prep_dma_cyclic; + dma->device_config = admac_device_config; + dma->device_pause = admac_pause; + dma->device_resume = admac_resume; + + dma->directions = BIT(DMA_MEM_TO_DEV) | BIT(DMA_DEV_TO_MEM); + dma->residue_granularity = DMA_RESIDUE_GRANULARITY_BURST; + dma->src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) | + BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) | + BIT(DMA_SLAVE_BUSWIDTH_4_BYTES); + 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 admac_chan *adchan = &ad->channels[i]; + + adchan->host = ad; + adchan->no = i; + adchan->chan.device = &ad->dma; + spin_lock_init(&adchan->lock); + INIT_LIST_HEAD(&adchan->submitted); + INIT_LIST_HEAD(&adchan->issued); + INIT_LIST_HEAD(&adchan->to_free); + list_add_tail(&adchan->chan.device_node, &dma->channels); + tasklet_setup(&adchan->tasklet, admac_chan_tasklet); + } + + err = reset_control_reset(ad->rstc); + if (err) + return dev_err_probe(&pdev->dev, err, + "unable to trigger reset\n"); + + err = request_irq(irq, admac_interrupt, 0, dev_name(&pdev->dev), ad); + if (err) { + dev_err_probe(&pdev->dev, err, + "unable to register interrupt\n"); + goto free_reset; + } + + err = dma_async_device_register(&ad->dma); + if (err) { + dev_err_probe(&pdev->dev, err, "failed to register DMA device\n"); + goto free_irq; + } + + err = of_dma_controller_register(pdev->dev.of_node, admac_dma_of_xlate, ad); + if (err) { + dma_async_device_unregister(&ad->dma); + dev_err_probe(&pdev->dev, err, "failed to register with OF\n"); + goto free_irq; + } + + ad->txcache.size = readl_relaxed(ad->base + REG_TX_SRAM_SIZE); + ad->rxcache.size = readl_relaxed(ad->base + REG_RX_SRAM_SIZE); + + dev_info(&pdev->dev, "Audio DMA Controller\n"); + dev_info(&pdev->dev, "imprint %x TX cache %u RX cache %u\n", + readl_relaxed(ad->base + REG_IMPRINT), ad->txcache.size, ad->rxcache.size); + + return 0; + +free_irq: + free_irq(ad->irq, ad); +free_reset: + reset_control_rearm(ad->rstc); + return err; +} + +static int admac_remove(struct platform_device *pdev) +{ + struct admac_data *ad = platform_get_drvdata(pdev); + + of_dma_controller_free(pdev->dev.of_node); + dma_async_device_unregister(&ad->dma); + free_irq(ad->irq, ad); + reset_control_rearm(ad->rstc); + + return 0; +} + +static const struct of_device_id admac_of_match[] = { + { .compatible = "apple,admac", }, + { } +}; +MODULE_DEVICE_TABLE(of, admac_of_match); + +static struct platform_driver apple_admac_driver = { + .driver = { + .name = "apple-admac", + .of_match_table = admac_of_match, + }, + .probe = admac_probe, + .remove = admac_remove, +}; +module_platform_driver(apple_admac_driver); + +MODULE_AUTHOR("Martin PoviĊĦer <povik+lin@cutebit.org>"); +MODULE_DESCRIPTION("Driver for Audio DMA Controller (ADMAC) on Apple SoCs"); +MODULE_LICENSE("GPL"); |