Add SSI DMAC support to RZ/G2L SoC.
Signed-off-by: Biju Das biju.das.jz@bp.renesas.com Reviewed-by: Lad Prabhakar prabhakar.mahadev-lad.rj@bp.renesas.com --- Note:- This patch has run time dependency on [1] [1] https://patchwork.kernel.org/project/linux-renesas-soc/patch/20210806095322....
v3->v4: * Updated the subject line as per style for the subsystem. * started using dmaengine_terminate_async instead of dmaengine_terminate_sync as it is called from atomic context. v2->v3: * Removed the passing legacy channel configuration parameters from dmaengine_slave_config function * started using dma_request_chan instead of deprecated dma_request_slave_channel v1->v2: * No change --- sound/soc/sh/rz-ssi.c | 256 ++++++++++++++++++++++++++++++++++++------ 1 file changed, 224 insertions(+), 32 deletions(-)
diff --git a/sound/soc/sh/rz-ssi.c b/sound/soc/sh/rz-ssi.c index 0809423a76fa..d1cde9d9207e 100644 --- a/sound/soc/sh/rz-ssi.c +++ b/sound/soc/sh/rz-ssi.c @@ -7,6 +7,7 @@ //
#include <linux/clk.h> +#include <linux/dmaengine.h> #include <linux/io.h> #include <linux/module.h> #include <linux/of_device.h> @@ -86,6 +87,7 @@ struct rz_ssi_stream { struct rz_ssi_priv *priv; struct snd_pcm_substream *substream; int fifo_sample_size; /* sample capacity of SSI FIFO */ + int dma_buffer_pos; /* The address for the next DMA descriptor */ int period_counter; /* for keeping track of periods transferred */ int sample_width; int buffer_pos; /* current frame position in the buffer */ @@ -94,6 +96,8 @@ struct rz_ssi_stream { int uerr_num; int oerr_num;
+ struct dma_chan *dma_ch; + int (*transfer)(struct rz_ssi_priv *ssi, struct rz_ssi_stream *strm); };
@@ -105,6 +109,7 @@ struct rz_ssi_priv { struct clk *sfr_clk; struct clk *clk;
+ phys_addr_t phys; int irq_int; int irq_tx; int irq_rx; @@ -128,8 +133,11 @@ struct rz_ssi_priv {
bool lrckp_fsync_fall; /* LR clock polarity (SSICR.LRCKP) */ bool bckp_rise; /* Bit clock polarity (SSICR.BCKP) */ + bool dma_rt; };
+static void rz_ssi_dma_complete(void *data); + static void rz_ssi_reg_writel(struct rz_ssi_priv *priv, uint reg, u32 data) { writel(data, (priv->base + reg)); @@ -175,6 +183,11 @@ rz_ssi_stream_get(struct rz_ssi_priv *ssi, struct snd_pcm_substream *substream) return stream; }
+static inline bool rz_ssi_is_dma_enabled(struct rz_ssi_priv *ssi) +{ + return (ssi->playback.dma_ch || ssi->capture.dma_ch); +} + static int rz_ssi_stream_is_valid(struct rz_ssi_priv *ssi, struct rz_ssi_stream *strm) { @@ -208,6 +221,7 @@ static int rz_ssi_stream_init(struct rz_ssi_priv *ssi,
strm->substream = substream; strm->sample_width = samples_to_bytes(runtime, 1); + strm->dma_buffer_pos = 0; strm->period_counter = 0; strm->buffer_pos = 0;
@@ -312,9 +326,12 @@ static int rz_ssi_start_stop(struct rz_ssi_priv *ssi, ssifcr = rz_ssi_reg_readl(ssi, SSIFCR) & ~0xF;
/* FIFO interrupt thresholds */ - rz_ssi_reg_writel(ssi, SSISCR, - SSISCR_TDES(strm->fifo_sample_size / 2 - 1) | - SSISCR_RDFS(0)); + if (rz_ssi_is_dma_enabled(ssi)) + rz_ssi_reg_writel(ssi, SSISCR, 0); + else + rz_ssi_reg_writel(ssi, SSISCR, + SSISCR_TDES(strm->fifo_sample_size / 2 - 1) | + SSISCR_RDFS(0));
/* enable IRQ */ if (is_play) { @@ -343,6 +360,10 @@ static int rz_ssi_start_stop(struct rz_ssi_priv *ssi, /* Disable TX/RX */ rz_ssi_reg_mask_setl(ssi, SSICR, SSICR_TEN | SSICR_REN, 0);
+ /* Cancel all remaining DMA transactions */ + if (rz_ssi_is_dma_enabled(ssi)) + dmaengine_terminate_async(strm->dma_ch); + /* Disable irqs */ rz_ssi_reg_mask_setl(ssi, SSICR, SSICR_TUIEN | SSICR_TOIEN | SSICR_RUIEN | SSICR_ROIEN, 0); @@ -559,12 +580,143 @@ static irqreturn_t rz_ssi_interrupt(int irq, void *data) return IRQ_HANDLED; }
+static int rz_ssi_dma_slave_config(struct rz_ssi_priv *ssi, + struct dma_chan *dma_ch, bool is_play) +{ + struct dma_slave_config cfg; + + memset(&cfg, 0, sizeof(cfg)); + + cfg.direction = is_play ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM; + cfg.dst_addr = ssi->phys + SSIFTDR; + cfg.src_addr = ssi->phys + SSIFRDR; + cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES; + cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES; + + return dmaengine_slave_config(dma_ch, &cfg); +} + +static int rz_ssi_dma_transfer(struct rz_ssi_priv *ssi, + struct rz_ssi_stream *strm) +{ + struct snd_pcm_substream *substream = strm->substream; + struct dma_async_tx_descriptor *desc; + struct snd_pcm_runtime *runtime; + enum dma_transfer_direction dir; + u32 dma_paddr, dma_size; + int amount; + + if (!rz_ssi_stream_is_valid(ssi, strm)) + return -EINVAL; + + runtime = substream->runtime; + if (runtime->status->state == SNDRV_PCM_STATE_DRAINING) + /* + * Stream is ending, so do not queue up any more DMA + * transfers otherwise we play partial sound clips + * because we can't shut off the DMA quick enough. + */ + return 0; + + dir = rz_ssi_stream_is_play(ssi, substream) ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM; + + /* Always transfer 1 period */ + amount = runtime->period_size; + + /* DMA physical address and size */ + dma_paddr = runtime->dma_addr + frames_to_bytes(runtime, + strm->dma_buffer_pos); + dma_size = frames_to_bytes(runtime, amount); + desc = dmaengine_prep_slave_single(strm->dma_ch, dma_paddr, dma_size, + dir, + DMA_PREP_INTERRUPT | DMA_CTRL_ACK); + if (!desc) { + dev_err(ssi->dev, "dmaengine_prep_slave_single() fail\n"); + return -ENOMEM; + } + + desc->callback = rz_ssi_dma_complete; + desc->callback_param = strm; + + if (dmaengine_submit(desc) < 0) { + dev_err(ssi->dev, "dmaengine_submit() fail\n"); + return -EIO; + } + + /* Update DMA pointer */ + strm->dma_buffer_pos += amount; + if (strm->dma_buffer_pos >= runtime->buffer_size) + strm->dma_buffer_pos = 0; + + /* Start DMA */ + dma_async_issue_pending(strm->dma_ch); + + return 0; +} + +static void rz_ssi_dma_complete(void *data) +{ + struct rz_ssi_stream *strm = (struct rz_ssi_stream *)data; + + if (!strm->running || !strm->substream || !strm->substream->runtime) + return; + + /* Note that next DMA transaction has probably already started */ + rz_ssi_pointer_update(strm, strm->substream->runtime->period_size); + + /* Queue up another DMA transaction */ + rz_ssi_dma_transfer(strm->priv, strm); +} + +static void rz_ssi_release_dma_channels(struct rz_ssi_priv *ssi) +{ + if (ssi->playback.dma_ch) { + dma_release_channel(ssi->playback.dma_ch); + ssi->playback.dma_ch = NULL; + if (ssi->dma_rt) + ssi->dma_rt = false; + } + + if (ssi->capture.dma_ch) { + dma_release_channel(ssi->capture.dma_ch); + ssi->capture.dma_ch = NULL; + } +} + +static int rz_ssi_dma_request(struct rz_ssi_priv *ssi, struct device *dev) +{ + ssi->playback.dma_ch = dma_request_chan(dev, "tx"); + ssi->capture.dma_ch = dma_request_chan(dev, "rx"); + if (!ssi->playback.dma_ch && !ssi->capture.dma_ch) { + ssi->playback.dma_ch = dma_request_chan(dev, "rt"); + if (!ssi->playback.dma_ch) + goto no_dma; + + ssi->dma_rt = true; + } + + if (ssi->playback.dma_ch && + (rz_ssi_dma_slave_config(ssi, ssi->playback.dma_ch, true) < 0)) + goto no_dma; + + if (ssi->capture.dma_ch && + (rz_ssi_dma_slave_config(ssi, ssi->capture.dma_ch, false) < 0)) + goto no_dma; + + return 0; + +no_dma: + rz_ssi_release_dma_channels(ssi); + + return -ENODEV; +} + static int rz_ssi_dai_trigger(struct snd_pcm_substream *substream, int cmd, struct snd_soc_dai *dai) { struct rz_ssi_priv *ssi = snd_soc_dai_get_drvdata(dai); struct rz_ssi_stream *strm = rz_ssi_stream_get(ssi, substream); - int ret = 0; + int ret = 0, i, num_transfer = 1; unsigned long flags;
switch (cmd) { @@ -580,9 +732,29 @@ static int rz_ssi_dai_trigger(struct snd_pcm_substream *substream, int cmd, if (ret) goto done;
- ret = strm->transfer(ssi, strm); - if (ret) - goto done; + if (ssi->dma_rt) { + bool is_playback; + + is_playback = rz_ssi_stream_is_play(ssi, substream); + ret = rz_ssi_dma_slave_config(ssi, ssi->playback.dma_ch, + is_playback); + /* Fallback to pio */ + if (ret < 0) { + ssi->playback.transfer = rz_ssi_pio_send; + ssi->capture.transfer = rz_ssi_pio_recv; + rz_ssi_release_dma_channels(ssi); + } + } + + /* For DMA, queue up multiple DMA descriptors */ + if (rz_ssi_is_dma_enabled(ssi)) + num_transfer = 4; + + for (i = 0; i < num_transfer; i++) { + ret = strm->transfer(ssi, strm); + if (ret) + goto done; + }
ret = rz_ssi_start_stop(ssi, strm, 1); break; @@ -743,6 +915,7 @@ static int rz_ssi_probe(struct platform_device *pdev) { struct rz_ssi_priv *ssi; struct clk *audio_clk; + struct resource *res; int ret;
ssi = devm_kzalloc(&pdev->dev, sizeof(*ssi), GFP_KERNEL); @@ -751,10 +924,11 @@ static int rz_ssi_probe(struct platform_device *pdev)
ssi->pdev = pdev; ssi->dev = &pdev->dev; - ssi->base = devm_platform_ioremap_resource(pdev, 0); + ssi->base = devm_platform_get_and_ioremap_resource(pdev, 0, &res); if (IS_ERR(ssi->base)) return PTR_ERR(ssi->base);
+ ssi->phys = res->start; ssi->clk = devm_clk_get(&pdev->dev, "ssi"); if (IS_ERR(ssi->clk)) return PTR_ERR(ssi->clk); @@ -781,8 +955,18 @@ static int rz_ssi_probe(struct platform_device *pdev)
ssi->audio_mck = ssi->audio_clk_1 ? ssi->audio_clk_1 : ssi->audio_clk_2;
- ssi->playback.transfer = rz_ssi_pio_send; - ssi->capture.transfer = rz_ssi_pio_recv; + /* Detect DMA support */ + ret = rz_ssi_dma_request(ssi, &pdev->dev); + if (ret < 0) { + dev_warn(&pdev->dev, "DMA not available, using PIO\n"); + ssi->playback.transfer = rz_ssi_pio_send; + ssi->capture.transfer = rz_ssi_pio_recv; + } else { + dev_info(&pdev->dev, "DMA enabled"); + ssi->playback.transfer = rz_ssi_dma_transfer; + ssi->capture.transfer = rz_ssi_dma_transfer; + } + ssi->playback.priv = ssi; ssi->capture.priv = ssi;
@@ -798,28 +982,32 @@ static int rz_ssi_probe(struct platform_device *pdev) return dev_err_probe(&pdev->dev, ret, "irq request error (int_req)\n");
- /* Tx and Rx interrupts (pio only) */ - ssi->irq_tx = platform_get_irq_byname(pdev, "dma_tx"); - if (ssi->irq_tx < 0) - return dev_err_probe(&pdev->dev, -ENODEV, - "Unable to get SSI dma_tx IRQ\n"); - - ret = devm_request_irq(&pdev->dev, ssi->irq_tx, &rz_ssi_interrupt, 0, - dev_name(&pdev->dev), ssi); - if (ret < 0) - return dev_err_probe(&pdev->dev, ret, - "irq request error (dma_tx)\n"); - - ssi->irq_rx = platform_get_irq_byname(pdev, "dma_rx"); - if (ssi->irq_rx < 0) - return dev_err_probe(&pdev->dev, -ENODEV, - "Unable to get SSI dma_rx IRQ\n"); - - ret = devm_request_irq(&pdev->dev, ssi->irq_rx, &rz_ssi_interrupt, 0, - dev_name(&pdev->dev), ssi); - if (ret < 0) - return dev_err_probe(&pdev->dev, ret, - "irq request error (dma_rx)\n"); + if (!rz_ssi_is_dma_enabled(ssi)) { + /* Tx and Rx interrupts (pio only) */ + ssi->irq_tx = platform_get_irq_byname(pdev, "dma_tx"); + if (ssi->irq_tx < 0) + return dev_err_probe(&pdev->dev, -ENODEV, + "Unable to get SSI dma_tx IRQ\n"); + + ret = devm_request_irq(&pdev->dev, ssi->irq_tx, + &rz_ssi_interrupt, 0, + dev_name(&pdev->dev), ssi); + if (ret < 0) + return dev_err_probe(&pdev->dev, ret, + "irq request error (dma_tx)\n"); + + ssi->irq_rx = platform_get_irq_byname(pdev, "dma_rx"); + if (ssi->irq_rx < 0) + return dev_err_probe(&pdev->dev, -ENODEV, + "Unable to get SSI dma_rx IRQ\n"); + + ret = devm_request_irq(&pdev->dev, ssi->irq_rx, + &rz_ssi_interrupt, 0, + dev_name(&pdev->dev), ssi); + if (ret < 0) + return dev_err_probe(&pdev->dev, ret, + "irq request error (dma_rx)\n"); + }
ssi->rstc = devm_reset_control_get_exclusive(&pdev->dev, NULL); if (IS_ERR(ssi->rstc)) @@ -835,6 +1023,8 @@ static int rz_ssi_probe(struct platform_device *pdev) rz_ssi_soc_dai, ARRAY_SIZE(rz_ssi_soc_dai)); if (ret < 0) { + rz_ssi_release_dma_channels(ssi); + pm_runtime_put(ssi->dev); pm_runtime_disable(ssi->dev); reset_control_assert(ssi->rstc); @@ -848,6 +1038,8 @@ static int rz_ssi_remove(struct platform_device *pdev) { struct rz_ssi_priv *ssi = dev_get_drvdata(&pdev->dev);
+ rz_ssi_release_dma_channels(ssi); + pm_runtime_put(ssi->dev); pm_runtime_disable(ssi->dev); reset_control_assert(ssi->rstc);