blob: 9588773dd2eb670a2f6115fdaef39a0e88248015 [file] [log] [blame]
// 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 PoviĊĦer <povik+lin@cutebit.org>");
MODULE_DESCRIPTION("Driver for Audio DMA Controller (ADMAC) on Apple SoCs");
MODULE_LICENSE("GPL");