[RFC,8/9] clk: meson: add auxiliary reset helper driver

Commit Message

Jerome Brunet May 16, 2024, 3:08 p.m. UTC

Add an helper module to register auxiliary reset drivers from
Amlogic clock controller.

Signed-off-by: Jerome Brunet <[e-mail]>
---
 drivers/clk/meson/Kconfig             |  5 ++
 drivers/clk/meson/Makefile            |  1 +
 drivers/clk/meson/meson-clk-rst-aux.c | 84 +++++++++++++++++++++++++++
 drivers/clk/meson/meson-clk-rst-aux.h | 14 +++++
 4 files changed, 104 insertions(+)
 create mode 100644 drivers/clk/meson/meson-clk-rst-aux.c
 create mode 100644 drivers/clk/meson/meson-clk-rst-aux.h

Comments

Stephen Boyd May 30, 2024, 1:01 a.m. UTC | #1

Quoting Jerome Brunet (2024-05-16 08:08:38)
> Add an helper module to register auxiliary reset drivers from
> Amlogic clock controller.
> 
> Signed-off-by: Jerome Brunet <[e-mail]>
> ---
>  drivers/clk/meson/Kconfig             |  5 ++
>  drivers/clk/meson/Makefile            |  1 +
>  drivers/clk/meson/meson-clk-rst-aux.c | 84 +++++++++++++++++++++++++++
>  drivers/clk/meson/meson-clk-rst-aux.h | 14 +++++
>  4 files changed, 104 insertions(+)
>  create mode 100644 drivers/clk/meson/meson-clk-rst-aux.c
>  create mode 100644 drivers/clk/meson/meson-clk-rst-aux.h
> 
> diff --git a/drivers/clk/meson/meson-clk-rst-aux.h b/drivers/clk/meson/meson-clk-rst-aux.h
> new file mode 100644
> index 000000000000..386a55a36cd9
> --- /dev/null
> +++ b/drivers/clk/meson/meson-clk-rst-aux.h
> @@ -0,0 +1,14 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (c) 2024 BayLibre, SAS.
> + * Author: Jerome Brunet <[e-mail]>
> + */
> +
> +#ifndef __MESON_CLK_RST_AUX_H
> +#define __MESON_CLK_RST_AUX_H
> +
> +int devm_meson_clk_rst_aux_register(struct device *dev,
> +                                   struct regmap *map,
> +                                   const char *adev_name);

I'd prefer we move the device creation and registration logic to
drivers/reset as well. See commit 098c290a490d ("clock, reset:
microchip: move all mpfs reset code to the reset subsystem") for some
inspiration.

One thing I haven't really thought about too much is if they're two
different modules. One for clk and one for reset. If the device
registration API is a symbol the clk module depends on then maybe that
is better because it means both modules are loaded, avoiding a
round-trip through modprobe. It also makes sure that the drivers are
either both builtin or both modular.

Patch

diff --git a/drivers/clk/meson/Kconfig b/drivers/clk/meson/Kconfig
index 59a40a49f8e1..6905aa2f080c 100644
--- a/drivers/clk/meson/Kconfig
+++ b/drivers/clk/meson/Kconfig
@@ -37,6 +37,11 @@  config COMMON_CLK_MESON_VCLK
 config COMMON_CLK_MESON_CLKC_UTILS
 	tristate
 
+config COMMON_CLK_MESON_CLK_RST_AUX
+	depends on REGMAP && AUXILIARY_BUS
+	imply RESET_MESON
+	tristate
+
 config COMMON_CLK_MESON_AO_CLKC
 	tristate
 	select COMMON_CLK_MESON_REGMAP
diff --git a/drivers/clk/meson/Makefile b/drivers/clk/meson/Makefile
index 9ba43fe7a07a..2926a04b6c33 100644
--- a/drivers/clk/meson/Makefile
+++ b/drivers/clk/meson/Makefile
@@ -2,6 +2,7 @@ 
 # Amlogic clock drivers
 
 obj-$(CONFIG_COMMON_CLK_MESON_CLKC_UTILS) += meson-clkc-utils.o
+obj-$(CONFIG_COMMON_CLK_MESON_CLK_RST_AUX) += meson-clk-rst-aux.o
 obj-$(CONFIG_COMMON_CLK_MESON_AO_CLKC) += meson-aoclk.o
 obj-$(CONFIG_COMMON_CLK_MESON_CPU_DYNDIV) += clk-cpu-dyndiv.o
 obj-$(CONFIG_COMMON_CLK_MESON_DUALDIV) += clk-dualdiv.o
diff --git a/drivers/clk/meson/meson-clk-rst-aux.c b/drivers/clk/meson/meson-clk-rst-aux.c
new file mode 100644
index 000000000000..a7cf3c39828c
--- /dev/null
+++ b/drivers/clk/meson/meson-clk-rst-aux.c
@@ -0,0 +1,84 @@ 
+// SPDX-License-Identifier: GPL-2.0
+//
+// Copyright (c) 2024 BayLibre, SAS.
+// Author: Jerome Brunet <[e-mail]>
+
+#include <linux/auxiliary_bus.h>
+#include <linux/idr.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+
+#include <soc/amlogic/meson8b-auxiliary-reset.h>
+
+#include "meson-clk-rst-aux.h"
+
+static DEFINE_IDA(meson_clk_rst_aux_ida);
+
+static void meson_clk_rst_aux_release(struct device *dev)
+{
+	struct auxiliary_device *adev = to_auxiliary_dev(dev);
+	struct meson8b_reset_adev *raux =
+		to_meson8b_reset_adev(adev);
+
+	ida_free(&meson_clk_rst_aux_ida, adev->id);
+	kfree(raux);
+}
+
+static void meson_clk_rst_aux_unregister_adev(void *_adev)
+{
+	struct auxiliary_device *adev = _adev;
+
+	auxiliary_device_delete(adev);
+	auxiliary_device_uninit(adev);
+}
+
+int devm_meson_clk_rst_aux_register(struct device *dev,
+				    struct regmap *map,
+				    const char *adev_name)
+{
+	struct meson8b_reset_adev *raux;
+	struct auxiliary_device *adev;
+	int ret;
+
+	raux = kzalloc(sizeof(*raux), GFP_KERNEL);
+	if (!raux)
+		return -ENOMEM;
+
+	ret = ida_alloc(&meson_clk_rst_aux_ida, GFP_KERNEL);
+	if (ret < 0)
+		goto raux_free;
+
+	raux->map = map;
+
+	adev = &raux->adev;
+	adev->id = ret;
+	adev->name = adev_name;
+	adev->dev.parent = dev;
+	adev->dev.release = meson_clk_rst_aux_release;
+	device_set_of_node_from_dev(&adev->dev, dev);
+
+	ret = auxiliary_device_init(adev);
+	if (ret)
+		goto ida_free;
+
+	ret = __auxiliary_device_add(adev, dev->driver->name);
+	if (ret) {
+		auxiliary_device_uninit(adev);
+		return ret;
+	}
+
+	return devm_add_action_or_reset(dev, meson_clk_rst_aux_unregister_adev,
+					adev);
+
+ida_free:
+	ida_free(&meson_clk_rst_aux_ida, adev->id);
+raux_free:
+	kfree(raux);
+	return ret;
+
+}
+EXPORT_SYMBOL_GPL(devm_meson_clk_rst_aux_register);
+
+MODULE_DESCRIPTION("Amlogic auxiliary reset helper for clock");
+MODULE_AUTHOR("Jerome Brunet <[e-mail]>");
+MODULE_LICENSE("GPL");
diff --git a/drivers/clk/meson/meson-clk-rst-aux.h b/drivers/clk/meson/meson-clk-rst-aux.h
new file mode 100644
index 000000000000..386a55a36cd9
--- /dev/null
+++ b/drivers/clk/meson/meson-clk-rst-aux.h
@@ -0,0 +1,14 @@ 
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2024 BayLibre, SAS.
+ * Author: Jerome Brunet <[e-mail]>
+ */
+
+#ifndef __MESON_CLK_RST_AUX_H
+#define __MESON_CLK_RST_AUX_H
+
+int devm_meson_clk_rst_aux_register(struct device *dev,
+				    struct regmap *map,
+				    const char *adev_name);
+
+#endif /* __MESON_CLK_RST_AUX_H */