From a33debe2706bf61f2cdc2732720533974472a5ae Mon Sep 17 00:00:00 2001
From: Tobias Poganiuch <tobias.poganiuch@seco.com>
Date: Wed, 9 Aug 2023 14:38:08 +0200
Subject: [PATCH] driver:ac97: Added dummy AC97 driver
---
drivers/staging/Kconfig | 2 +
drivers/staging/Makefile | 1 +
drivers/staging/misc/Kconfig | 18 ++++
drivers/staging/misc/Makefile | 6 ++
drivers/staging/misc/mumpitz.c | 157 +++++++++++++++++++++++++++++++++
5 files changed, 184 insertions(+)
create mode 100644 drivers/staging/misc/Kconfig
create mode 100644 drivers/staging/misc/Makefile
create mode 100644 drivers/staging/misc/mumpitz.c
diff --git a/drivers/staging/Kconfig b/drivers/staging/Kconfig
index c08f68800a932..2f741a1611add 100644
--- a/drivers/staging/Kconfig
+++ b/drivers/staging/Kconfig
@@ -116,4 +116,6 @@ source "drivers/staging/mfd/Kconfig"
source "drivers/staging/input/Kconfig"
+source "drivers/staging/misc/Kconfig"
+
endif # STAGING
diff --git a/drivers/staging/Makefile b/drivers/staging/Makefile
index 69c83d0823728..81221eaa28d1a 100644
--- a/drivers/staging/Makefile
+++ b/drivers/staging/Makefile
@@ -48,3 +48,4 @@ obj-y += gpio/
obj-y += gpu/drm/
obj-y += mfd/
obj-y += input/
+obj-y += misc/
diff --git a/drivers/staging/misc/Kconfig b/drivers/staging/misc/Kconfig
new file mode 100644
index 0000000000000..8943f86d05a4b
--- /dev/null
+++ b/drivers/staging/misc/Kconfig
@@ -0,0 +1,18 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Misc drivers
+#
+
+menu "Misc"
+
+config AC97_MUMPITZ
+ bool "Dummy device driver for AC97"
+ select REGMAP_AC97
+ select AC97_BUS_COMPAT
+ depends on AC97_BUS_NEW
+ help
+ Say yes here to enable the dummy device driver for AC97.
+ The driver polls an WM9705 Codec in fixed intervals to
+ simulate AC97 traffic.
+
+endmenu
diff --git a/drivers/staging/misc/Makefile b/drivers/staging/misc/Makefile
new file mode 100644
index 0000000000000..9aecaf6d5381d
--- /dev/null
+++ b/drivers/staging/misc/Makefile
@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for misc drivers
+#
+
+obj-$(CONFIG_AC97_MUMPITZ) += mumpitz.o
diff --git a/drivers/staging/misc/mumpitz.c b/drivers/staging/misc/mumpitz.c
new file mode 100644
index 0000000000000..5e08c5e24523d
--- /dev/null
+++ b/drivers/staging/misc/mumpitz.c
@@ -0,0 +1,157 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include <linux/regmap.h>
+#include <linux/workqueue.h>
+#include <sound/ac97/codec.h>
+#include <sound/ac97/compat.h>
+
+#define MUMPITZ_VENDOR_ID 0x574d4c05
+#define MUMPITZ_VENDOR_ID_MASK 0xffffffff
+#define MUMPITZ_WORK_INTERVAL 10
+
+struct mumpitz_platform_data {
+ struct snd_ac97 *ac97;
+ struct regmap *regmap;
+};
+
+struct mumpitz_priv {
+ struct regmap *regmap;
+ struct snd_ac97 *ac97;
+ struct device *dev;
+ struct mumpitz_platform_data codec_pdata;
+ int vendor_id1;
+ int vendor_id2;
+
+ struct delayed_work reader;
+ struct workqueue_struct *workq;
+};
+
+/* AC97 Read/Write */
+
+int mumpitz_ac97_reg_read(struct mumpitz_priv *mup, u16 reg)
+{
+ if (mup->ac97)
+ return mup->ac97->bus->ops->read(mup->ac97, reg);
+ else
+ return -1;
+}
+
+void mumpitz_ac97_reg_write(struct mumpitz_priv *mup, u16 reg, u16 val)
+{
+ if (mup->ac97)
+ mup->ac97->bus->ops->write(mup->ac97, reg, val);
+}
+
+/* Driver */
+
+static void mumpitz_ac97_worker(struct work_struct *work)
+{
+ struct mumpitz_priv *mup = container_of(work, struct mumpitz_priv,
+ reader.work);
+
+ dev_dbg(mup->dev, "Test #1");
+
+ /* Read/Write to AC97 Codec */
+
+ queue_delayed_work(mup->workq, &mup->reader,
+ MUMPITZ_WORK_INTERVAL);
+}
+
+static int mumpitz_ac97_probe(struct ac97_codec_device *adev)
+{
+ struct mumpitz_priv *mumpitz;
+ const struct regmap_config *config;
+ struct mumpitz_platform_data *codec_pdata;
+ int ret = -ENODEV;
+
+ mumpitz = devm_kzalloc(ac97_codec_dev2dev(adev),
+ sizeof(*mumpitz), GFP_KERNEL);
+
+ if (!mumpitz)
+ return -ENOMEM;
+
+ mumpitz->dev = ac97_codec_dev2dev(adev);
+ mumpitz->ac97 = snd_ac97_compat_alloc(adev);
+
+ if (IS_ERR(mumpitz->ac97))
+ return PTR_ERR(mumpitz->ac97);
+
+ ac97_set_drvdata(adev, mumpitz);
+ dev_info(mumpitz->dev, "mumpitz core found, id=0x%x\n",
+ adev->vendor_id);
+
+ codec_pdata = &mumpitz->codec_pdata;
+ codec_pdata->ac97 = mumpitz->ac97;
+
+ if (adev->vendor_id != MUMPITZ_VENDOR_ID)
+ goto err_free_compat;
+
+ codec_pdata->regmap = devm_regmap_init_ac97(mumpitz->ac97, config);
+
+ if (IS_ERR(codec_pdata->regmap)) {
+ ret = PTR_ERR(codec_pdata->regmap);
+ goto err_free_compat;
+ }
+
+ /* Check for supported codec */
+
+ mumpitz->vendor_id1 = mumpitz_ac97_reg_read(mumpitz, AC97_VENDOR_ID1);
+
+ if (mumpitz->vendor_id1 != (MUMPITZ_VENDOR_ID >> 4)) {
+ dev_err(mumpitz->dev, "Device with vendor %04x is not a mumpitz\n",
+ mumpitz->vendor_id1);
+ return -ENODEV;
+ }
+
+ mumpitz->vendor_id2 = mumpitz_ac97_reg_read(mumpitz, AC97_VENDOR_ID2);
+
+ dev_info(mumpitz->dev, "id1: %04x id2: %04x",
+ mumpitz->vendor_id1, mumpitz->vendor_id2);
+
+ /* Start AC97 Polling */
+
+ mumpitz->workq = alloc_ordered_workqueue("kmumpitz", 0);
+
+ if (mumpitz->workq == NULL) {
+ dev_err(mumpitz->dev,
+ "Failed to create workqueue\n");
+ return -EINVAL;
+ }
+
+ INIT_DELAYED_WORK(&mumpitz->reader, mumpitz_ac97_worker);
+
+ queue_delayed_work(mumpitz->workq, &mumpitz->reader,
+ MUMPITZ_WORK_INTERVAL);
+
+ if (ret)
+ goto err_free_compat;
+
+ return ret;
+
+err_free_compat:
+ snd_ac97_compat_release(mumpitz->ac97);
+ return ret;
+}
+
+static int mumpitz_ac97_remove(struct ac97_codec_device *adev)
+{
+ struct mumpitz_priv *mumpitz = ac97_get_drvdata(adev);
+
+ snd_ac97_compat_release(mumpitz->ac97);
+
+ return 0;
+}
+
+static const struct ac97_id mumpitz_ac97_ids[] = {
+ { .id = MUMPITZ_VENDOR_ID, .mask = MUMPITZ_VENDOR_ID_MASK },
+ { }
+};
+
+static struct ac97_codec_driver mumpitz_ac97_driver = {
+ .driver = {
+ .name = "mumpitz",
+ },
+ .probe = mumpitz_ac97_probe,
+ .remove = mumpitz_ac97_remove,
+ .id_table = mumpitz_ac97_ids,
+};
--
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