From 7069d8ecc61afe003a1cbe20a2a4c29c67dedeae Mon Sep 17 00:00:00 2001
From: Jerome Brunet <jbrunet@baylibre.com>
Date: Tue, 22 Oct 2019 14:03:49 +0200
Subject: [PATCH 49/94] WIP: ASoC: meson: add aiu bus support

The AIU is audio playback subsystem of the legacy Amlogic SoC, such as
the gxbb, gxl and gxm family.

Blabla

Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
---
 sound/soc/meson/Kconfig   |  7 ++++
 sound/soc/meson/Makefile  |  2 ++
 sound/soc/meson/aiu-bus.c | 82 +++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 91 insertions(+)
 create mode 100644 sound/soc/meson/aiu-bus.c

diff --git a/sound/soc/meson/Kconfig b/sound/soc/meson/Kconfig
index 4c1ced9..5b15077 100644
--- a/sound/soc/meson/Kconfig
+++ b/sound/soc/meson/Kconfig
@@ -2,6 +2,13 @@
 menu "ASoC support for Amlogic platforms"
 	depends on ARCH_MESON || COMPILE_TEST
 
+config SND_MESON_AIU_BUS
+	tristate "Amlogic AIU bus support"
+	select REGMAP_MMIO
+	help
+	  Select Y or M to add support for audio output interfaces
+	  embedded in the Amlogic GX SoC families
+
 config SND_MESON_AXG_FIFO
 	tristate
 	select REGMAP_MMIO
diff --git a/sound/soc/meson/Makefile b/sound/soc/meson/Makefile
index 5331c41..6c89ab3 100644
--- a/sound/soc/meson/Makefile
+++ b/sound/soc/meson/Makefile
@@ -1,5 +1,6 @@
 # SPDX-License-Identifier: (GPL-2.0 OR MIT)
 
+snd-soc-meson-aiu-bus-objs := aiu-bus.o
 snd-soc-meson-axg-fifo-objs := axg-fifo.o
 snd-soc-meson-axg-frddr-objs := axg-frddr.o
 snd-soc-meson-axg-toddr-objs := axg-toddr.o
@@ -16,6 +17,7 @@ snd-soc-meson-g12a-toacodec-objs := g12a-toacodec.o
 snd-soc-meson-g12a-tohdmitx-objs := g12a-tohdmitx.o
 snd-soc-meson-t9015-objs := t9015.o
 
+obj-$(CONFIG_SND_MESON_AIU_BUS) += snd-soc-meson-aiu-bus.o
 obj-$(CONFIG_SND_MESON_AXG_FIFO) += snd-soc-meson-axg-fifo.o
 obj-$(CONFIG_SND_MESON_AXG_FRDDR) += snd-soc-meson-axg-frddr.o
 obj-$(CONFIG_SND_MESON_AXG_TODDR) += snd-soc-meson-axg-toddr.o
diff --git a/sound/soc/meson/aiu-bus.c b/sound/soc/meson/aiu-bus.c
new file mode 100644
index 0000000..479c5e6
--- /dev/null
+++ b/sound/soc/meson/aiu-bus.c
@@ -0,0 +1,82 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// Copyright (c) 2019 BayLibre, SAS.
+// Author: Jerome Brunet <jbrunet@baylibre.com>
+
+#include <linux/clk.h>
+#include <linux/module.h>
+#include <linux/of_platform.h>
+#include <linux/reset.h>
+
+static const char * const aiu_bus_clk_names[] = { "top", "glue", };
+
+static int aiu_bus_enable_pclks(struct device *dev)
+{
+	struct clk *clock;
+	int i, ret;
+
+	for (i = 0; i < ARRAY_SIZE(aiu_bus_clk_names); i++) {
+		clock = devm_clk_get(dev, aiu_bus_clk_names[i]);
+		if (IS_ERR(clock)) {
+			if (PTR_ERR(clock) != -EPROBE_DEFER)
+				dev_err(dev, "Failed to get %s clock\n",
+					aiu_bus_clk_names[i]);
+			return PTR_ERR(clock);
+		}
+
+		ret = clk_prepare_enable(clock);
+		if (ret) {
+			dev_err(dev, "Failed to enable %s clock\n",
+				aiu_bus_clk_names[i]);
+			return ret;
+		}
+
+		ret = devm_add_action_or_reset(dev,
+				(void(*)(void *))clk_disable_unprepare,
+				clock);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+static const struct of_device_id aiu_bus_of_match[] = {
+	{
+		.compatible = "amlogic,aiu-bus",
+		.data = NULL,
+	}, {}
+};
+MODULE_DEVICE_TABLE(of, aiu_bus_of_match);
+
+static int aiu_bus_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	int ret;
+
+	/* Fire and forget bus pclks */
+	ret = aiu_bus_enable_pclks(dev);
+	if (ret)
+		return ret;
+
+	ret = device_reset(dev);
+	if (ret) {
+		dev_err(dev, "reset failed\n");
+		return ret;
+	}
+
+	return devm_of_platform_populate(dev);
+}
+
+static struct platform_driver aiu_bus_pdrv = {
+	.probe = aiu_bus_probe,
+	.driver = {
+		.name = "meson-aiu-bus",
+		.of_match_table = aiu_bus_of_match,
+	},
+};
+module_platform_driver(aiu_bus_pdrv);
+
+MODULE_DESCRIPTION("Amlogic AIU bus driver");
+MODULE_AUTHOR("Jerome Brunet <jbrunet@baylibre.com>");
+MODULE_LICENSE("GPL v2");
-- 
2.7.1