[PATCH] ASoC: fsl: Add generic CPU DAI driver

[Daniel Baluta (OSS)]

From: Daniel Baluta <daniel.baluta@xxxxxxx>

On i.MX8 platforms that have a DSP the DAI handling is taken care
of by two entities:
	* Application Processor (AP), which runs Linux
	* DSP, which runs a firmware (typically Sound Open Firmware)

The DSP has access to DAI IP registers, but it cannot easily handle
resources like:
	* clocks
	* power domain management
	* pinctrl

For this reason we introduce a generic FSL DAI driver which will take
care of the resources above.
---
 sound/soc/fsl/Kconfig   |   8 ++
 sound/soc/fsl/Makefile  |   2 +
 sound/soc/fsl/fsl_dai.c | 276 ++++++++++++++++++++++++++++++++++++++++
 3 files changed, 286 insertions(+)
 create mode 100644 sound/soc/fsl/fsl_dai.c

diff --git a/sound/soc/fsl/Kconfig b/sound/soc/fsl/Kconfig
index 65e8cd4be930..bea8ab2c24f9 100644
--- a/sound/soc/fsl/Kconfig
+++ b/sound/soc/fsl/Kconfig
@@ -75,6 +75,14 @@ config SND_SOC_FSL_ESAI
 	  This option is only useful for out-of-tree drivers since
 	  in-tree drivers select it automatically.
 
+config SND_SOC_FSL_DAI
+	tristate "Generic FSL DAI support for Sound Open Firmware"
+	help
+	  Say Y if you want to enable generic FSL DAI support to be used
+	  with Sound Open Firmware. This module takes care of enabling
+	  clocks, power domain, pinctrl for FSL DAIs. The rest of DAI
+	  control is taken care of by SOF firmware.
+
 config SND_SOC_FSL_MICFIL
 	tristate "Pulse Density Modulation Microphone Interface (MICFIL) module support"
 	select REGMAP_MMIO
diff --git a/sound/soc/fsl/Makefile b/sound/soc/fsl/Makefile
index 8cde88c72d93..e4ed253b6657 100644
--- a/sound/soc/fsl/Makefile
+++ b/sound/soc/fsl/Makefile
@@ -20,6 +20,7 @@ snd-soc-fsl-ssi-y := fsl_ssi.o
 snd-soc-fsl-ssi-$(CONFIG_DEBUG_FS) += fsl_ssi_dbg.o
 snd-soc-fsl-spdif-objs := fsl_spdif.o
 snd-soc-fsl-esai-objs := fsl_esai.o
+snd-soc-fsl-dai-objs := fsl_dai.o
 snd-soc-fsl-micfil-objs := fsl_micfil.o
 snd-soc-fsl-utils-objs := fsl_utils.o
 snd-soc-fsl-dma-objs := fsl_dma.o
@@ -32,6 +33,7 @@ obj-$(CONFIG_SND_SOC_FSL_SAI) += snd-soc-fsl-sai.o
 obj-$(CONFIG_SND_SOC_FSL_SSI) += snd-soc-fsl-ssi.o
 obj-$(CONFIG_SND_SOC_FSL_SPDIF) += snd-soc-fsl-spdif.o
 obj-$(CONFIG_SND_SOC_FSL_ESAI) += snd-soc-fsl-esai.o
+obj-$(CONFIG_SND_SOC_FSL_DAI) += snd-soc-fsl-dai.o
 obj-$(CONFIG_SND_SOC_FSL_MICFIL) += snd-soc-fsl-micfil.o
 obj-$(CONFIG_SND_SOC_FSL_UTILS) += snd-soc-fsl-utils.o
 obj-$(CONFIG_SND_SOC_FSL_MQS) += snd-soc-fsl-mqs.o
diff --git a/sound/soc/fsl/fsl_dai.c b/sound/soc/fsl/fsl_dai.c
new file mode 100644
index 000000000000..f70889939801
--- /dev/null
+++ b/sound/soc/fsl/fsl_dai.c
@@ -0,0 +1,276 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// Freescale Generic DAI driver for DSP
+//
+// Copyright 2019 NXP
+// Author: Daniel Baluta <daniel.baluta@xxxxxxx>
+
+#include <linux/clk.h>
+#include <linux/module.h>
+#include <linux/pm_runtime.h>
+#include <linux/pm_domain.h>
+#include <sound/pcm_params.h>
+#include <sound/soc.h>
+
+enum fsl_dai_type {
+	FSL_DAI_TYPE_NONE,
+	FSL_DAI_TYPE_SAI,
+	FSL_DAI_TYPE_ESAI,
+};
+
+#define FSL_DAI_ESAI_CLK_NUM	4
+static const char *esai_clks[FSL_DAI_ESAI_CLK_NUM] = {
+	"core",
+	"extal",
+	"fsys",
+	"spba",
+};
+
+#define FSL_DAI_SAI_CLK_NUM	5
+static const char *sai_clks[FSL_DAI_SAI_CLK_NUM] = {
+	"bus",
+	"mclk0",
+	"mclk1",
+	"mclk2",
+	"mclk3",
+};
+
+struct fsl_dai {
+	struct platform_device *pdev;
+
+	/* DAI clocks */
+	struct clk **clks;
+	const char **clk_names;
+	int num_clks;
+
+	/* Power Domain handling */
+	int num_domains;
+	struct device **pd_dev;
+	struct device_link **link;
+
+	/* DAIS */
+	struct snd_soc_dai_driver *dai_drv;
+	int num_drv;
+};
+
+static struct snd_soc_dai_driver fsl_esai_dai = {
+	.name = "esai0",
+};
+
+static struct snd_soc_dai_driver fsl_sai_dai = {
+	.name = "sai1",
+};
+
+static const struct snd_soc_component_driver fsl_dai_component = {
+	.name = "fsl-dai",
+};
+
+static int fsl_dai_init_clocks(struct fsl_dai *dai_priv)
+{
+	struct device *dev = &dai_priv->pdev->dev;
+	int i;
+
+	dai_priv->clks = devm_kcalloc(dev, dai_priv->num_clks,
+				      sizeof(*dai_priv->clks), GFP_KERNEL);
+	if (!dai_priv->clks)
+		return -ENOMEM;
+
+	for (i = 0; i < dai_priv->num_clks; i++) {
+		dai_priv->clks[i] = devm_clk_get(dev, dai_priv->clk_names[i]);
+		if (IS_ERR(dai_priv->clks[i])) {
+			dev_dbg(dev, "Failed to get clk %s\n",
+				dai_priv->clk_names[i]);
+			dai_priv->clks[i] = NULL;
+		}
+	}
+
+	return 0;
+}
+
+int fsl_get_dai_type(struct fsl_dai *dai_priv)
+{
+	struct device_node *np = dai_priv->pdev->dev.of_node;
+
+	if (of_device_is_compatible(np, "fsl,esai-dai"))
+		return FSL_DAI_TYPE_ESAI;
+
+	if (of_device_is_compatible(np, "fsl,sai-dai"))
+		return FSL_DAI_TYPE_SAI;
+
+	return FSL_DAI_TYPE_NONE;
+}
+
+static int fsl_dai_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct fsl_dai *priv;
+	int dai_type;
+	int ret;
+	int i;
+
+	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->pdev = pdev;
+
+	dev_set_drvdata(&pdev->dev, priv);
+
+	dai_type = fsl_get_dai_type(priv);
+	switch (dai_type) {
+	case FSL_DAI_TYPE_ESAI:
+		priv->clk_names = esai_clks;
+		priv->num_clks = FSL_DAI_ESAI_CLK_NUM;
+		priv->dai_drv = &fsl_esai_dai;
+		priv->num_drv = 1;
+		break;
+	case FSL_DAI_TYPE_SAI:
+		priv->clk_names = sai_clks;
+		priv->num_clks = FSL_DAI_SAI_CLK_NUM;
+		priv->dai_drv = &fsl_sai_dai;
+		priv->num_drv = 1;
+		break;
+	default:
+		dev_err(&pdev->dev, "Invalid DAI type %d\n", dai_type);
+		return -EINVAL;
+	}
+
+	ret = fsl_dai_init_clocks(priv);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "Error at init clocks\n");
+		return ret;
+	}
+
+	priv->num_domains = of_count_phandle_with_args(np, "power-domains",
+						       "#power-domain-cells");
+	if (priv->num_domains < 0) {
+		dev_err(&pdev->dev, "no power-domains property in %pOF\n", np);
+		return priv->num_domains;
+	}
+
+	priv->pd_dev = devm_kmalloc_array(&pdev->dev, priv->num_domains,
+					  sizeof(*priv->pd_dev), GFP_KERNEL);
+	if (!priv->pd_dev)
+		return -ENOMEM;
+
+	priv->link = devm_kmalloc_array(&pdev->dev, priv->num_domains,
+					sizeof(*priv->link), GFP_KERNEL);
+	if (!priv->link)
+		return -ENOMEM;
+
+	for (i = 0; i < priv->num_domains; i++) {
+		priv->pd_dev[i] = dev_pm_domain_attach_by_id(&pdev->dev, i);
+		if (IS_ERR(priv->pd_dev[i])) {
+			ret = PTR_ERR(priv->pd_dev[i]);
+			goto unroll_pm;
+		}
+
+		priv->link[i] = device_link_add(&pdev->dev, priv->pd_dev[i],
+						DL_FLAG_STATELESS |
+						DL_FLAG_PM_RUNTIME |
+						DL_FLAG_RPM_ACTIVE);
+		if (!priv->link[i]) {
+			ret = -EINVAL;
+			dev_pm_domain_detach(priv->pd_dev[i], false);
+			goto unroll_pm;
+		}
+	}
+
+	pm_runtime_enable(&pdev->dev);
+
+	ret = devm_snd_soc_register_component(&pdev->dev, &fsl_dai_component,
+					      priv->dai_drv, priv->num_drv);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "Failed to register DAI ret = %d\n", ret);
+		return ret;
+	}
+	return 0;
+
+unroll_pm:
+	while (--i >= 0) {
+		device_link_del(priv->link[i]);
+		dev_pm_domain_detach(priv->pd_dev[i], false);
+	}
+	return ret;
+}
+
+static int fsl_dai_remove(struct platform_device *pdev)
+{
+	struct fsl_dai *priv = platform_get_drvdata(pdev);
+	int i;
+
+	pm_runtime_disable(&priv->pdev->dev);
+
+	for (i = 0; i < priv->num_domains; i++) {
+		device_link_del(priv->link[i]);
+		dev_pm_domain_detach(priv->pd_dev[i], false);
+	}
+
+	return 0;
+}
+
+static const struct of_device_id fsl_dai_dt_ids[] = {
+	{ .compatible = "fsl,esai-dai", },
+	{ .compatible = "fsl,sai-dai", },
+	{}
+};
+MODULE_DEVICE_TABLE(of, fsl_dai_dt_ids);
+
+#ifdef CONFIG_PM
+static int fsl_dai_runtime_resume(struct device *dev)
+{
+	struct fsl_dai *priv = dev_get_drvdata(dev);
+	int i, ret;
+
+	for (i = 0; i < priv->num_clks; i++) {
+		ret = clk_prepare_enable(priv->clks[i]);
+		if (ret < 0) {
+			dev_err(dev, "Failed to enable clk %s\n",
+				priv->clk_names[i]);
+			goto out;
+		}
+	}
+	return 0;
+out:
+	while (--i >= 0)
+		clk_disable_unprepare(priv->clks[i]);
+
+	return ret;
+}
+
+static int fsl_dai_runtime_suspend(struct device *dev)
+{
+	struct fsl_dai *priv = dev_get_drvdata(dev);
+	int i;
+
+	for (i = 0; i < priv->num_clks; i++)
+		clk_disable_unprepare(priv->clks[i]);
+
+	return 0;
+}
+#endif /* CONFIG_PM */
+
+static const struct dev_pm_ops fsl_dai_pm_ops = {
+	SET_RUNTIME_PM_OPS(fsl_dai_runtime_suspend,
+			   fsl_dai_runtime_resume, NULL)
+	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
+				pm_runtime_force_resume)
+};
+
+static struct platform_driver fsl_dai_driver = {
+	.probe = fsl_dai_probe,
+	.remove = fsl_dai_remove,
+	.driver = {
+		.name = "fsl-dai",
+		.pm = &fsl_dai_pm_ops,
+		.of_match_table = fsl_dai_dt_ids,
+	},
+};
+
+module_platform_driver(fsl_dai_driver);
+
+MODULE_ALIAS("platform:fsl-dai");
+
+MODULE_AUTHOR("Daniel Baluta <daniel.baluta@xxxxxxx>");
+MODULE_DESCRIPTION("FSL Generic DAI driver for DSP");
+MODULE_LICENSE("GPL v2");
-- 
2.17.1