linux/drivers/dma/apple-admac.c
Hector Martin 306f5df81f dmaengine: apple-admac: Keep upper bits of REG_BUS_WIDTH
For RX channels, REG_BUS_WIDTH seems to default to a value of 0xf00, and
macOS preserves the upper bits when setting the configuration in the
lower ones. If we reset the upper bits to 0, this causes framing errors
on suspend/resume (the data stream "tears" and channels get swapped
around). Keeping the upper bits untouched, like the macOS driver does,
fixes this issue.

Signed-off-by: Hector Martin <marcan@marcan.st>
Reviewed-by: Martin Povišer <povik+lin@cutebit.org>
Signed-off-by: Martin Povišer <povik+lin@cutebit.org>
Link: https://lore.kernel.org/r/20231029170704.82238-1-povik+lin@cutebit.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>
2023-11-24 18:57:56 +05:30

960 lines
25 KiB
C

// 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.h>
#include <linux/of_dma.h>
#include <linux/platform_device.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_WORD_SIZE GENMASK(3, 0)
#define BUS_WIDTH_FRAME_SIZE GENMASK(7, 4)
#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[] __counted_by(nchannels);
};
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 = readl_relaxed(ad->base + REG_BUS_WIDTH(adchan->no)) &
~(BUS_WIDTH_WORD_SIZE | BUS_WIDTH_FRAME_SIZE);
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 void 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);
}
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_new = admac_remove,
};
module_platform_driver(apple_admac_driver);
MODULE_AUTHOR("Martin Povišer <povik+lin@cutebit.org>");
MODULE_DESCRIPTION("Driver for Audio DMA Controller (ADMAC) on Apple SoCs");
MODULE_LICENSE("GPL");