Applied "ASoC: fsl_ssi: Move DT related code to a separate probe()" to the asoc tree

[Mark Brown <broonie@kernel.org>]

The patch

   ASoC: fsl_ssi: Move DT related code to a separate probe()

has been applied to the asoc tree at

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git 

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.  

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark

>From 76f3845110d7d40eb60c12bc64cdfe431a985947 Mon Sep 17 00:00:00 2001
From: Nicolin Chen <nicoleotsuka@gmail.com>
Date: Mon, 12 Feb 2018 14:03:24 -0800
Subject: [PATCH] ASoC: fsl_ssi: Move DT related code to a separate probe()

This patch cleans up probe() function by moving all Device Tree
related code into a separate function. It allows the probe() to
be Device Tree independent. This will be very useful for future
integration of imx-ssi driver which has similar functionalities
while exists only because it supports non-DT cases.

This patch also moves symmetric_channels of AC97 from the probe
to the structure snd_soc_dai_driver for simplification.

Additionally, since PowerPC and AC97 use the same pdev pointer
to register a platform device, this patch also unifies related
code.

Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
Tested-by: Caleb Crome <caleb@crome.org>
Tested-by: Maciej S. Szmigiero <mail@maciej.szmigiero.name>
Reviewed-by: Maciej S. Szmigiero <mail@maciej.szmigiero.name>
Signed-off-by: Mark Brown <broonie@kernel.org>
---
 sound/soc/fsl/fsl_ssi.c | 219 +++++++++++++++++++++++++++---------------------
 1 file changed, 124 insertions(+), 95 deletions(-)

diff --git a/sound/soc/fsl/fsl_ssi.c b/sound/soc/fsl/fsl_ssi.c
index b58fabe77c6f..5bc67ad8000f 100644
--- a/sound/soc/fsl/fsl_ssi.c
+++ b/sound/soc/fsl/fsl_ssi.c
@@ -239,8 +239,12 @@ struct fsl_ssi_soc_data {
  *
  * @fiq_params: FIQ stream filtering parameters
  *
- * @pdev: Pointer to pdev when using fsl-ssi as sound card (ppc only)
- *        TODO: Should be replaced with simple-sound-card
+ * @card_pdev: Platform_device pointer to register a sound card for PowerPC or
+ *             to register a CODEC platform device for AC97
+ * @card_name: Platform_device name to register a sound card for PowerPC or
+ *             to register a CODEC platform device for AC97
+ * @card_idx: The index of SSI to register a sound card for PowerPC or
+ *            to register a CODEC platform device for AC97
  *
  * @dbg_stats: Debugging statistics
  *
@@ -285,7 +289,9 @@ struct fsl_ssi {
 
 	struct imx_pcm_fiq_params fiq_params;
 
-	struct platform_device *pdev;
+	struct platform_device *card_pdev;
+	char card_name[32];
+	u32 card_idx;
 
 	struct fsl_ssi_dbg dbg_stats;
 
@@ -1134,6 +1140,7 @@ static const struct snd_soc_component_driver fsl_ssi_component = {
 
 static struct snd_soc_dai_driver fsl_ssi_ac97_dai = {
 	.bus_control = true,
+	.symmetric_channels = 1,
 	.probe = fsl_ssi_dai_probe,
 	.playback = {
 		.stream_name = "AC97 Playback",
@@ -1291,9 +1298,7 @@ static void make_lowercase(char *s)
 static int fsl_ssi_imx_probe(struct platform_device *pdev,
 			     struct fsl_ssi *ssi, void __iomem *iomem)
 {
-	struct device_node *np = pdev->dev.of_node;
 	struct device *dev = &pdev->dev;
-	u32 dmas[4];
 	int ret;
 
 	/* Backward compatible for a DT without ipg clock name assigned */
@@ -1327,14 +1332,8 @@ static int fsl_ssi_imx_probe(struct platform_device *pdev,
 	ssi->dma_params_tx.addr = ssi->ssi_phys + REG_SSI_STX0;
 	ssi->dma_params_rx.addr = ssi->ssi_phys + REG_SSI_SRX0;
 
-	/* Set to dual FIFO mode according to the SDMA sciprt */
-	ret = of_property_read_u32_array(np, "dmas", dmas, 4);
-	if (ssi->use_dma && !ret && dmas[2] == IMX_DMATYPE_SSI_DUAL) {
-		ssi->use_dual_fifo = true;
-		/*
-		 * Use even numbers to avoid channel swap due to SDMA
-		 * script design
-		 */
+	/* Use even numbers to avoid channel swap due to SDMA script design */
+	if (ssi->use_dual_fifo) {
 		ssi->dma_params_tx.maxburst &= ~0x1;
 		ssi->dma_params_rx.maxburst &= ~0x1;
 	}
@@ -1375,41 +1374,109 @@ static void fsl_ssi_imx_clean(struct platform_device *pdev, struct fsl_ssi *ssi)
 		clk_disable_unprepare(ssi->clk);
 }
 
-static int fsl_ssi_probe(struct platform_device *pdev)
+static int fsl_ssi_probe_from_dt(struct fsl_ssi *ssi)
 {
-	struct fsl_ssi *ssi;
-	int ret = 0;
-	struct device_node *np = pdev->dev.of_node;
-	struct device *dev = &pdev->dev;
+	struct device *dev = ssi->dev;
+	struct device_node *np = dev->of_node;
 	const struct of_device_id *of_id;
 	const char *p, *sprop;
 	const __be32 *iprop;
-	struct resource *res;
-	void __iomem *iomem;
-	char name[64];
-	struct regmap_config regconfig = fsl_ssi_regconfig;
+	u32 dmas[4];
+	int ret;
 
 	of_id = of_match_device(fsl_ssi_ids, dev);
 	if (!of_id || !of_id->data)
 		return -EINVAL;
 
-	ssi = devm_kzalloc(dev, sizeof(*ssi), GFP_KERNEL);
-	if (!ssi)
-		return -ENOMEM;
-
 	ssi->soc = of_id->data;
-	ssi->dev = dev;
+
+	ret = of_property_match_string(np, "clock-names", "ipg");
+	/* Get error code if not found */
+	ssi->has_ipg_clk_name = ret >= 0;
 
 	/* Check if being used in AC97 mode */
 	sprop = of_get_property(np, "fsl,mode", NULL);
-	if (sprop) {
-		if (!strcmp(sprop, "ac97-slave"))
-			ssi->dai_fmt = FSLSSI_AC97_DAIFMT;
+	if (sprop && !strcmp(sprop, "ac97-slave")) {
+		ssi->dai_fmt = FSLSSI_AC97_DAIFMT;
+
+		ret = of_property_read_u32(np, "cell-index", &ssi->card_idx);
+		if (ret) {
+			dev_err(dev, "failed to get SSI index property\n");
+			return -EINVAL;
+		}
+		strcpy(ssi->card_name, "ac97-codec");
+	} else if (!of_find_property(np, "fsl,ssi-asynchronous", NULL)) {
+		/*
+		 * In synchronous mode, STCK and STFS ports are used by RX
+		 * as well. So the software should limit the sample rates,
+		 * sample bits and channels to be symmetric.
+		 *
+		 * This is exclusive with FSLSSI_AC97_FORMATS as AC97 runs
+		 * in the SSI synchronous mode however it does not have to
+		 * limit symmetric sample rates and sample bits.
+		 */
+		ssi->synchronous = true;
 	}
 
 	/* Select DMA or FIQ */
 	ssi->use_dma = !of_property_read_bool(np, "fsl,fiq-stream-filter");
 
+	/* Fetch FIFO depth; Set to 8 for older DT without this property */
+	iprop = of_get_property(np, "fsl,fifo-depth", NULL);
+	if (iprop)
+		ssi->fifo_depth = be32_to_cpup(iprop);
+	else
+		ssi->fifo_depth = 8;
+
+	/* Use dual FIFO mode depending on the support from SDMA script */
+	ret = of_property_read_u32_array(np, "dmas", dmas, 4);
+	if (ssi->use_dma && !ret && dmas[2] == IMX_DMATYPE_SSI_DUAL)
+		ssi->use_dual_fifo = true;
+
+	/*
+	 * Backward compatible for older bindings by manually triggering the
+	 * machine driver's probe(). Use /compatible property, including the
+	 * address of CPU DAI driver structure, as the name of machine driver
+	 *
+	 * If card_name is set by AC97 earlier, bypass here since it uses a
+	 * different name to register the device.
+	 */
+	if (!ssi->card_name[0] && of_get_property(np, "codec-handle", NULL)) {
+		sprop = of_get_property(of_find_node_by_path("/"),
+					"compatible", NULL);
+		/* Strip "fsl," in the compatible name if applicable */
+		p = strrchr(sprop, ',');
+		if (p)
+			sprop = p + 1;
+		snprintf(ssi->card_name, sizeof(ssi->card_name),
+			 "snd-soc-%s", sprop);
+		make_lowercase(ssi->card_name);
+		ssi->card_idx = 0;
+	}
+
+	return 0;
+}
+
+static int fsl_ssi_probe(struct platform_device *pdev)
+{
+	struct regmap_config regconfig = fsl_ssi_regconfig;
+	struct device *dev = &pdev->dev;
+	struct fsl_ssi *ssi;
+	struct resource *res;
+	void __iomem *iomem;
+	int ret = 0;
+
+	ssi = devm_kzalloc(dev, sizeof(*ssi), GFP_KERNEL);
+	if (!ssi)
+		return -ENOMEM;
+
+	ssi->dev = dev;
+
+	/* Probe from DT */
+	ret = fsl_ssi_probe_from_dt(ssi);
+	if (ret)
+		return ret;
+
 	if (fsl_ssi_is_ac97(ssi)) {
 		memcpy(&ssi->cpu_dai_drv, &fsl_ssi_ac97_dai,
 		       sizeof(fsl_ssi_ac97_dai));
@@ -1433,15 +1500,11 @@ static int fsl_ssi_probe(struct platform_device *pdev)
 			REG_SSI_SRMSK / sizeof(uint32_t) + 1;
 	}
 
-	ret = of_property_match_string(np, "clock-names", "ipg");
-	if (ret < 0) {
-		ssi->has_ipg_clk_name = false;
-		ssi->regs = devm_regmap_init_mmio(dev, iomem, &regconfig);
-	} else {
-		ssi->has_ipg_clk_name = true;
+	if (ssi->has_ipg_clk_name)
 		ssi->regs = devm_regmap_init_mmio_clk(dev, "ipg", iomem,
 						      &regconfig);
-	}
+	else
+		ssi->regs = devm_regmap_init_mmio(dev, iomem, &regconfig);
 	if (IS_ERR(ssi->regs)) {
 		dev_err(dev, "failed to init register map\n");
 		return PTR_ERR(ssi->regs);
@@ -1453,24 +1516,13 @@ static int fsl_ssi_probe(struct platform_device *pdev)
 		return ssi->irq;
 	}
 
-	/* Set software limitations for synchronous mode */
-	if (!of_find_property(np, "fsl,ssi-asynchronous", NULL)) {
-		if (!fsl_ssi_is_ac97(ssi)) {
-			ssi->cpu_dai_drv.symmetric_rates = 1;
-			ssi->cpu_dai_drv.symmetric_samplebits = 1;
-			ssi->synchronous = true;
-		}
-
+	/* Set software limitations for synchronous mode except AC97 */
+	if (ssi->synchronous && !fsl_ssi_is_ac97(ssi)) {
+		ssi->cpu_dai_drv.symmetric_rates = 1;
 		ssi->cpu_dai_drv.symmetric_channels = 1;
+		ssi->cpu_dai_drv.symmetric_samplebits = 1;
 	}
 
-	/* Fetch FIFO depth; Set to 8 for older DT without this property */
-	iprop = of_get_property(np, "fsl,fifo-depth", NULL);
-	if (iprop)
-		ssi->fifo_depth = be32_to_cpup(iprop);
-	else
-		ssi->fifo_depth = 8;
-
 	/*
 	 * Configure TX and RX DMA watermarks -- when to send a DMA request
 	 *
@@ -1535,50 +1587,27 @@ static int fsl_ssi_probe(struct platform_device *pdev)
 	if (ret)
 		goto error_asoc_register;
 
-	/* Bypass it if using newer DT bindings of ASoC machine drivers */
-	if (!of_get_property(np, "codec-handle", NULL))
-		goto done;
-
-	/*
-	 * Backward compatible for older bindings by manually triggering the
-	 * machine driver's probe(). Use /compatible property, including the
-	 * address of CPU DAI driver structure, as the name of machine driver.
-	 */
-	sprop = of_get_property(of_find_node_by_path("/"), "compatible", NULL);
-	/* Sometimes the compatible name has a "fsl," prefix, so we strip it. */
-	p = strrchr(sprop, ',');
-	if (p)
-		sprop = p + 1;
-	snprintf(name, sizeof(name), "snd-soc-%s", sprop);
-	make_lowercase(name);
-
-	ssi->pdev = platform_device_register_data(dev, name, 0, NULL, 0);
-	if (IS_ERR(ssi->pdev)) {
-		ret = PTR_ERR(ssi->pdev);
-		dev_err(dev, "failed to register platform: %d\n", ret);
-		goto error_sound_card;
-	}
-
-done:
 	/* Initially configures SSI registers */
 	fsl_ssi_hw_init(ssi);
 
-	if (fsl_ssi_is_ac97(ssi)) {
-		u32 ssi_idx;
-
-		ret = of_property_read_u32(np, "cell-index", &ssi_idx);
-		if (ret) {
-			dev_err(dev, "failed to get SSI index property\n");
-			goto error_sound_card;
-		}
-
-		ssi->pdev = platform_device_register_data(NULL, "ac97-codec",
-							  ssi_idx, NULL, 0);
-		if (IS_ERR(ssi->pdev)) {
-			ret = PTR_ERR(ssi->pdev);
-			dev_err(dev,
-				"failed to register AC97 codec platform: %d\n",
-				ret);
+	/* Register a platform device for older bindings or AC97 */
+	if (ssi->card_name[0]) {
+		struct device *parent = dev;
+		/*
+		 * Do not set SSI dev as the parent of AC97 CODEC device since
+		 * it does not have a DT node. Otherwise ASoC core will assume
+		 * CODEC has the same DT node as the SSI, so it may bypass the
+		 * dai_probe() of SSI and then cause NULL DMA data pointers.
+		 */
+		if (fsl_ssi_is_ac97(ssi))
+			parent = NULL;
+
+		ssi->card_pdev = platform_device_register_data(parent,
+				ssi->card_name, ssi->card_idx, NULL, 0);
+		if (IS_ERR(ssi->card_pdev)) {
+			ret = PTR_ERR(ssi->card_pdev);
+			dev_err(dev, "failed to register %s: %d\n",
+				ssi->card_name, ret);
 			goto error_sound_card;
 		}
 	}
@@ -1606,8 +1635,8 @@ static int fsl_ssi_remove(struct platform_device *pdev)
 
 	fsl_ssi_debugfs_remove(&ssi->dbg_stats);
 
-	if (ssi->pdev)
-		platform_device_unregister(ssi->pdev);
+	if (ssi->card_pdev)
+		platform_device_unregister(ssi->card_pdev);
 
 	/* Clean up SSI registers */
 	fsl_ssi_hw_clean(ssi);
-- 
2.16.1