Add audio support for the Renesas RZ/G3S SoC

Merge series from Claudiu <[e-mail]>:

Series enables the audio support for the Renesas RZ/G3S
SoC along with runtime PM and suspend to RAM.

Documentation/devicetree/bindings/sound/renesas,rz-ssi.yaml

···
           - renesas,r9a07g043-ssi  # RZ/G2UL and RZ/Five
           - renesas,r9a07g044-ssi  # RZ/G2{L,LC}
           - renesas,r9a07g054-ssi  # RZ/V2L
+          - renesas,r9a08g045-ssi  # RZ/G3S
       - const: renesas,rz-ssi
 
   reg:
···
   dmas:
     minItems: 1
     maxItems: 2
-    description:
-      The first cell represents a phandle to dmac.
-      The second cell specifies the encoded MID/RID values of the SSI port
-      connected to the DMA client and the slave channel configuration
-      parameters.
-      bits[0:9]   - Specifies MID/RID value of a SSI channel as below
-                    MID/RID value of SSI rx0 = 0x256
-                    MID/RID value of SSI tx0 = 0x255
-                    MID/RID value of SSI rx1 = 0x25a
-                    MID/RID value of SSI tx1 = 0x259
-                    MID/RID value of SSI rt2 = 0x25f
-                    MID/RID value of SSI rx3 = 0x262
-                    MID/RID value of SSI tx3 = 0x261
-      bit[10]     - HIEN = 1, Detects a request in response to the rising edge
-                    of the signal
-      bit[11]     - LVL = 0, Detects based on the edge
-      bits[12:14] - AM = 2, Bus cycle mode
-      bit[15]     - TM = 0, Single transfer mode
 
   dma-names:
     oneOf:

sound/soc/renesas/rz-ssi.c

···
 #include <linux/clk.h>
 #include <linux/dmaengine.h>
 #include <linux/io.h>
+#include <linux/iopoll.h>
 #include <linux/module.h>
 #include <linux/pm_runtime.h>
 #include <linux/reset.h>
···
 #define PREALLOC_BUFFER		(SZ_32K)
 #define PREALLOC_BUFFER_MAX	(SZ_32K)
 
-#define SSI_RATES		SNDRV_PCM_RATE_8000_48000 /* 8k-44.1kHz */
+#define SSI_RATES		SNDRV_PCM_RATE_8000_48000 /* 8k-48kHz */
 #define SSI_FMTS		SNDRV_PCM_FMTBIT_S16_LE
 #define SSI_CHAN_MIN		2
 #define SSI_CHAN_MAX		2
···
 
 struct rz_ssi_priv {
 	void __iomem *base;
-	struct platform_device *pdev;
 	struct reset_control *rstc;
 	struct device *dev;
 	struct clk *sfr_clk;
···
 	writel(val, (priv->base + reg));
 }
 
-static inline struct snd_soc_dai *
-rz_ssi_get_dai(struct snd_pcm_substream *substream)
-{
-	struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
-
-	return snd_soc_rtd_to_cpu(rtd, 0);
-}
-
-static inline bool rz_ssi_stream_is_play(struct rz_ssi_priv *ssi,
-					 struct snd_pcm_substream *substream)
+static inline bool rz_ssi_stream_is_play(struct snd_pcm_substream *substream)
 {
 	return substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
 }
···
 static void rz_ssi_stream_quit(struct rz_ssi_priv *ssi,
 			       struct rz_ssi_stream *strm)
 {
-	struct snd_soc_dai *dai = rz_ssi_get_dai(strm->substream);
+	struct device *dev = ssi->dev;
 
 	rz_ssi_set_substream(strm, NULL);
 
 	if (strm->oerr_num > 0)
-		dev_info(dai->dev, "overrun = %d\n", strm->oerr_num);
+		dev_info(dev, "overrun = %d\n", strm->oerr_num);
 
 	if (strm->uerr_num > 0)
-		dev_info(dai->dev, "underrun = %d\n", strm->uerr_num);
+		dev_info(dev, "underrun = %d\n", strm->uerr_num);
 }
 
 static int rz_ssi_clk_setup(struct rz_ssi_priv *ssi, unsigned int rate,
 			    unsigned int channels)
 {
-	static s8 ckdv[16] = { 1,  2,  4,  8, 16, 32, 64, 128,
-			       6, 12, 24, 48, 96, -1, -1, -1 };
+	static u8 ckdv[] = { 1,  2,  4,  8, 16, 32, 64, 128, 6, 12, 24, 48, 96 };
 	unsigned int channel_bits = 32;	/* System Word Length */
 	unsigned long bclk_rate = rate * channels * channel_bits;
 	unsigned int div;
···
 
 static void rz_ssi_set_idle(struct rz_ssi_priv *ssi)
 {
-	int timeout;
+	u32 tmp;
+	int ret;
 
 	/* Disable irqs */
 	rz_ssi_reg_mask_setl(ssi, SSICR, SSICR_TUIEN | SSICR_TOIEN |
···
 			      SSISR_RUIRQ), 0);
 
 	/* Wait for idle */
-	timeout = 100;
-	while (--timeout) {
-		if (rz_ssi_reg_readl(ssi, SSISR) & SSISR_IIRQ)
-			break;
-		udelay(1);
-	}
-
-	if (!timeout)
-		dev_info(ssi->dev, "timeout waiting for SSI idle\n");
+	ret = readl_poll_timeout_atomic(ssi->base + SSISR, tmp, (tmp & SSISR_IIRQ), 1, 100);
+	if (ret)
+		dev_warn_ratelimited(ssi->dev, "timeout waiting for SSI idle\n");
 
 	/* Hold FIFOs in reset */
 	rz_ssi_reg_mask_setl(ssi, SSIFCR, 0, SSIFCR_FIFO_RST);
···
 
 static int rz_ssi_start(struct rz_ssi_priv *ssi, struct rz_ssi_stream *strm)
 {
-	bool is_play = rz_ssi_stream_is_play(ssi, strm->substream);
+	bool is_play = rz_ssi_stream_is_play(strm->substream);
 	bool is_full_duplex;
 	u32 ssicr, ssifcr;
 
···
 	return 0;
 }
 
+static int rz_ssi_swreset(struct rz_ssi_priv *ssi)
+{
+	u32 tmp;
+
+	rz_ssi_reg_mask_setl(ssi, SSIFCR, 0, SSIFCR_SSIRST);
+	rz_ssi_reg_mask_setl(ssi, SSIFCR, SSIFCR_SSIRST, 0);
+	return readl_poll_timeout_atomic(ssi->base + SSIFCR, tmp, !(tmp & SSIFCR_SSIRST), 1, 5);
+}
+
 static int rz_ssi_stop(struct rz_ssi_priv *ssi, struct rz_ssi_stream *strm)
 {
 	strm->running = 0;
···
 	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);
+	if (rz_ssi_is_dma_enabled(ssi)) {
+		if (ssi->playback.dma_ch)
+			dmaengine_terminate_async(ssi->playback.dma_ch);
+		if (ssi->capture.dma_ch)
+			dmaengine_terminate_async(ssi->capture.dma_ch);
+	}
 
 	rz_ssi_set_idle(ssi);
 
···
 		 */
 		return 0;
 
-	dir = rz_ssi_stream_is_play(ssi, substream) ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM;
+	dir = rz_ssi_stream_is_play(substream) ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM;
 
 	/* Always transfer 1 period */
 	amount = runtime->period_size;
···
 	return -ENODEV;
 }
 
+static int rz_ssi_trigger_resume(struct rz_ssi_priv *ssi)
+{
+	int ret;
+
+	if (rz_ssi_is_stream_running(&ssi->playback) ||
+	    rz_ssi_is_stream_running(&ssi->capture))
+		return 0;
+
+	ret = rz_ssi_swreset(ssi);
+	if (ret)
+		return ret;
+
+	return rz_ssi_clk_setup(ssi, ssi->hw_params_cache.rate,
+				ssi->hw_params_cache.channels);
+}
+
+static void rz_ssi_streams_suspend(struct rz_ssi_priv *ssi)
+{
+	if (rz_ssi_is_stream_running(&ssi->playback) ||
+	    rz_ssi_is_stream_running(&ssi->capture))
+		return;
+
+	ssi->playback.dma_buffer_pos = 0;
+	ssi->capture.dma_buffer_pos = 0;
+}
+
 static int rz_ssi_dai_trigger(struct snd_pcm_substream *substream, int cmd,
 			      struct snd_soc_dai *dai)
 {
···
 	int ret = 0, i, num_transfer = 1;
 
 	switch (cmd) {
-	case SNDRV_PCM_TRIGGER_START:
-		/* Soft Reset */
-		if (!rz_ssi_is_stream_running(&ssi->playback) &&
-		    !rz_ssi_is_stream_running(&ssi->capture)) {
-			rz_ssi_reg_mask_setl(ssi, SSIFCR, 0, SSIFCR_SSIRST);
-			rz_ssi_reg_mask_setl(ssi, SSIFCR, SSIFCR_SSIRST, 0);
-			udelay(5);
-		}
+	case SNDRV_PCM_TRIGGER_RESUME:
+		ret = rz_ssi_trigger_resume(ssi);
+		if (ret)
+			return ret;
 
-		rz_ssi_stream_init(strm, substream);
+		fallthrough;
+
+	case SNDRV_PCM_TRIGGER_START:
+		if (cmd == SNDRV_PCM_TRIGGER_START)
+			rz_ssi_stream_init(strm, substream);
 
 		if (ssi->dma_rt) {
 			bool is_playback;
 
-			is_playback = rz_ssi_stream_is_play(ssi, substream);
+			is_playback = rz_ssi_stream_is_play(substream);
 			ret = rz_ssi_dma_slave_config(ssi, ssi->playback.dma_ch,
 						      is_playback);
 			/* Fallback to pio */
···
 
 		ret = rz_ssi_start(ssi, strm);
 		break;
+
+	case SNDRV_PCM_TRIGGER_SUSPEND:
+		rz_ssi_stop(ssi, strm);
+		rz_ssi_streams_suspend(ssi);
+		break;
+
 	case SNDRV_PCM_TRIGGER_STOP:
 		rz_ssi_stop(ssi, strm);
 		rz_ssi_stream_quit(ssi, strm);
···
 					SNDRV_PCM_HW_PARAM_SAMPLE_BITS)->min;
 	unsigned int channels = params_channels(params);
 	unsigned int rate = params_rate(params);
+	int ret;
 
 	if (sample_bits != 16) {
 		dev_err(ssi->dev, "Unsupported sample width: %d\n",
···
 	rz_ssi_cache_hw_params(ssi, rate, channels, strm->sample_width,
 			       sample_bits);
 
+	ret = rz_ssi_swreset(ssi);
+	if (ret)
+		return ret;
+
 	return rz_ssi_clk_setup(ssi, rate, channels);
 }
 
···
 static const struct snd_pcm_hardware rz_ssi_pcm_hardware = {
 	.info			= SNDRV_PCM_INFO_INTERLEAVED	|
 				  SNDRV_PCM_INFO_MMAP		|
-				  SNDRV_PCM_INFO_MMAP_VALID,
+				  SNDRV_PCM_INFO_MMAP_VALID	|
+				  SNDRV_PCM_INFO_RESUME,
 	.buffer_bytes_max	= PREALLOC_BUFFER,
 	.period_bytes_min	= 32,
 	.period_bytes_max	= 8192,
···
 static snd_pcm_uframes_t rz_ssi_pcm_pointer(struct snd_soc_component *component,
 					    struct snd_pcm_substream *substream)
 {
-	struct snd_soc_dai *dai = rz_ssi_get_dai(substream);
+	struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
+	struct snd_soc_dai *dai = snd_soc_rtd_to_cpu(rtd, 0);
 	struct rz_ssi_priv *ssi = snd_soc_dai_get_drvdata(dai);
 	struct rz_ssi_stream *strm = rz_ssi_stream_get(ssi, substream);
 
···
 
 static int rz_ssi_probe(struct platform_device *pdev)
 {
+	struct device *dev = &pdev->dev;
 	struct rz_ssi_priv *ssi;
 	struct clk *audio_clk;
 	struct resource *res;
 	int ret;
 
-	ssi = devm_kzalloc(&pdev->dev, sizeof(*ssi), GFP_KERNEL);
+	ssi = devm_kzalloc(dev, sizeof(*ssi), GFP_KERNEL);
 	if (!ssi)
 		return -ENOMEM;
 
-	ssi->pdev = pdev;
-	ssi->dev = &pdev->dev;
+	ssi->dev = dev;
 	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");
+	ssi->clk = devm_clk_get(dev, "ssi");
 	if (IS_ERR(ssi->clk))
 		return PTR_ERR(ssi->clk);
 
-	ssi->sfr_clk = devm_clk_get(&pdev->dev, "ssi_sfr");
+	ssi->sfr_clk = devm_clk_get(dev, "ssi_sfr");
 	if (IS_ERR(ssi->sfr_clk))
 		return PTR_ERR(ssi->sfr_clk);
 
-	audio_clk = devm_clk_get(&pdev->dev, "audio_clk1");
+	audio_clk = devm_clk_get(dev, "audio_clk1");
 	if (IS_ERR(audio_clk))
 		return dev_err_probe(&pdev->dev, PTR_ERR(audio_clk),
 				     "no audio clk1");
 
 	ssi->audio_clk_1 = clk_get_rate(audio_clk);
-	audio_clk = devm_clk_get(&pdev->dev, "audio_clk2");
+	audio_clk = devm_clk_get(dev, "audio_clk2");
 	if (IS_ERR(audio_clk))
 		return dev_err_probe(&pdev->dev, PTR_ERR(audio_clk),
 				     "no audio clk2");
···
 	ssi->audio_mck = ssi->audio_clk_1 ? ssi->audio_clk_1 : ssi->audio_clk_2;
 
 	/* Detect DMA support */
-	ret = rz_ssi_dma_request(ssi, &pdev->dev);
+	ret = rz_ssi_dma_request(ssi, dev);
 	if (ret < 0) {
-		dev_warn(&pdev->dev, "DMA not available, using PIO\n");
+		dev_warn(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");
+		dev_info(dev, "DMA enabled");
 		ssi->playback.transfer = rz_ssi_dma_transfer;
 		ssi->capture.transfer = rz_ssi_dma_transfer;
 	}
···
 	ssi->capture.priv = ssi;
 
 	spin_lock_init(&ssi->lock);
-	dev_set_drvdata(&pdev->dev, ssi);
+	dev_set_drvdata(dev, ssi);
 
 	/* Error Interrupt */
 	ssi->irq_int = platform_get_irq_byname(pdev, "int_req");
 	if (ssi->irq_int < 0) {
-		rz_ssi_release_dma_channels(ssi);
-		return ssi->irq_int;
+		ret = ssi->irq_int;
+		goto err_release_dma_chs;
 	}
 
-	ret = devm_request_irq(&pdev->dev, ssi->irq_int, &rz_ssi_interrupt,
-			       0, dev_name(&pdev->dev), ssi);
+	ret = devm_request_irq(dev, ssi->irq_int, &rz_ssi_interrupt,
+			       0, dev_name(dev), ssi);
 	if (ret < 0) {
-		rz_ssi_release_dma_channels(ssi);
-		return dev_err_probe(&pdev->dev, ret,
-				     "irq request error (int_req)\n");
+		dev_err_probe(dev, ret, "irq request error (int_req)\n");
+		goto err_release_dma_chs;
 	}
 
 	if (!rz_ssi_is_dma_enabled(ssi)) {
···
 			if (ssi->irq_rt < 0)
 				return ssi->irq_rt;
 
-			ret = devm_request_irq(&pdev->dev, ssi->irq_rt,
+			ret = devm_request_irq(dev, ssi->irq_rt,
 					       &rz_ssi_interrupt, 0,
-					       dev_name(&pdev->dev), ssi);
+					       dev_name(dev), ssi);
 			if (ret < 0)
-				return dev_err_probe(&pdev->dev, ret,
+				return dev_err_probe(dev, ret,
 						     "irq request error (dma_rt)\n");
 		} else {
 			if (ssi->irq_tx < 0)
···
 			if (ssi->irq_rx < 0)
 				return ssi->irq_rx;
 
-			ret = devm_request_irq(&pdev->dev, ssi->irq_tx,
+			ret = devm_request_irq(dev, ssi->irq_tx,
 					       &rz_ssi_interrupt, 0,
-					       dev_name(&pdev->dev), ssi);
+					       dev_name(dev), ssi);
 			if (ret < 0)
-				return dev_err_probe(&pdev->dev, ret,
+				return dev_err_probe(dev, ret,
 						"irq request error (dma_tx)\n");
 
-			ret = devm_request_irq(&pdev->dev, ssi->irq_rx,
+			ret = devm_request_irq(dev, ssi->irq_rx,
 					       &rz_ssi_interrupt, 0,
-					       dev_name(&pdev->dev), ssi);
+					       dev_name(dev), ssi);
 			if (ret < 0)
-				return dev_err_probe(&pdev->dev, ret,
+				return dev_err_probe(dev, ret,
 						"irq request error (dma_rx)\n");
 		}
 	}
 
-	ssi->rstc = devm_reset_control_get_exclusive(&pdev->dev, NULL);
+	ssi->rstc = devm_reset_control_get_exclusive(dev, NULL);
 	if (IS_ERR(ssi->rstc)) {
 		ret = PTR_ERR(ssi->rstc);
-		goto err_reset;
+		goto err_release_dma_chs;
 	}
 
-	reset_control_deassert(ssi->rstc);
-	pm_runtime_enable(&pdev->dev);
-	ret = pm_runtime_resume_and_get(&pdev->dev);
+	/* Default 0 for power saving. Can be overridden via sysfs. */
+	pm_runtime_set_autosuspend_delay(dev, 0);
+	pm_runtime_use_autosuspend(dev);
+	ret = devm_pm_runtime_enable(dev);
 	if (ret < 0) {
-		dev_err(&pdev->dev, "pm_runtime_resume_and_get failed\n");
-		goto err_pm;
+		dev_err(dev, "Failed to enable runtime PM!\n");
+		goto err_release_dma_chs;
 	}
 
-	ret = devm_snd_soc_register_component(&pdev->dev, &rz_ssi_soc_component,
+	ret = devm_snd_soc_register_component(dev, &rz_ssi_soc_component,
 					      rz_ssi_soc_dai,
 					      ARRAY_SIZE(rz_ssi_soc_dai));
 	if (ret < 0) {
-		dev_err(&pdev->dev, "failed to register snd component\n");
-		goto err_snd_soc;
+		dev_err(dev, "failed to register snd component\n");
+		goto err_release_dma_chs;
 	}
 
 	return 0;
 
-err_snd_soc:
-	pm_runtime_put(ssi->dev);
-err_pm:
-	pm_runtime_disable(ssi->dev);
-	reset_control_assert(ssi->rstc);
-err_reset:
+err_release_dma_chs:
 	rz_ssi_release_dma_channels(ssi);
 
 	return ret;
···
 
 	rz_ssi_release_dma_channels(ssi);
 
-	pm_runtime_put(ssi->dev);
-	pm_runtime_disable(ssi->dev);
 	reset_control_assert(ssi->rstc);
 }
 
···
 };
 MODULE_DEVICE_TABLE(of, rz_ssi_of_match);
 
+static int rz_ssi_runtime_suspend(struct device *dev)
+{
+	struct rz_ssi_priv *ssi = dev_get_drvdata(dev);
+
+	return reset_control_assert(ssi->rstc);
+}
+
+static int rz_ssi_runtime_resume(struct device *dev)
+{
+	struct rz_ssi_priv *ssi = dev_get_drvdata(dev);
+
+	return reset_control_deassert(ssi->rstc);
+}
+
+static const struct dev_pm_ops rz_ssi_pm_ops = {
+	RUNTIME_PM_OPS(rz_ssi_runtime_suspend, rz_ssi_runtime_resume, NULL)
+	SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, pm_runtime_force_resume)
+};
+
 static struct platform_driver rz_ssi_driver = {
 	.driver	= {
 		.name	= "rz-ssi-pcm-audio",
 		.of_match_table = rz_ssi_of_match,
+		.pm = pm_ptr(&rz_ssi_pm_ops),
 	},
 	.probe		= rz_ssi_probe,
 	.remove		= rz_ssi_remove,