[RFC,10/11] reset: imx: Add audiomix reset controller support
diff mbox series

Message ID 1583226206-19758-11-git-send-email-abel.vesa@nxp.com
State New
Headers show
Series
  • Add generic MFD i.MX mix and audiomix support
Related show

Commit Message

Abel Vesa March 3, 2020, 9:03 a.m. UTC
The imx-mix MFD driver registers some devices, one of which, in case of
audiomix, maps correctly to a reset controller type. This driver registers
a reset controller for that. For now, only the EARC specific resets are added.

Signed-off-by: Abel Vesa <abel.vesa@nxp.com>
Reviewed-by: Leonard Crestez <leonard.crestez@nxp.com>
---
 drivers/reset/Kconfig                          |   7 ++
 drivers/reset/Makefile                         |   1 +
 drivers/reset/reset-imx-audiomix.c             | 122 +++++++++++++++++++++++++
 include/dt-bindings/reset/imx-audiomix-reset.h |  15 +++
 4 files changed, 145 insertions(+)
 create mode 100644 drivers/reset/reset-imx-audiomix.c
 create mode 100644 include/dt-bindings/reset/imx-audiomix-reset.h

Comments

Philipp Zabel March 4, 2020, 11:41 a.m. UTC | #1
Hi Abel,

On Tue, 2020-03-03 at 11:03 +0200, Abel Vesa wrote:
> The imx-mix MFD driver registers some devices, one of which, in case of
> audiomix, maps correctly to a reset controller type. This driver registers
> a reset controller for that. For now, only the EARC specific resets are added.
> 
> Signed-off-by: Abel Vesa <abel.vesa@nxp.com>
> Reviewed-by: Leonard Crestez <leonard.crestez@nxp.com>
> ---
>  drivers/reset/Kconfig                          |   7 ++
>  drivers/reset/Makefile                         |   1 +
>  drivers/reset/reset-imx-audiomix.c             | 122 +++++++++++++++++++++++++
>  include/dt-bindings/reset/imx-audiomix-reset.h |  15 +++
>  4 files changed, 145 insertions(+)
>  create mode 100644 drivers/reset/reset-imx-audiomix.c
>  create mode 100644 include/dt-bindings/reset/imx-audiomix-reset.h
> 
> diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig
> index d9efbfd..2f8d9b3 100644
> --- a/drivers/reset/Kconfig
> +++ b/drivers/reset/Kconfig
> @@ -81,6 +81,13 @@ config RESET_INTEL_GW
>  	  Say Y to control the reset signals provided by reset controller.
>  	  Otherwise, say N.
>  
> +config RESET_IMX_AUDIOMIX
> +	bool "i.MX Audiomix Reset Driver" if COMPILE_TEST
> +	depends on HAS_IOMEM
> +	default ARCH_MXC
> +	help
> +	  This enables the audiomix reset controller driver for i.MX SoCs.
> +
>  config RESET_LANTIQ
>  	bool "Lantiq XWAY Reset Driver" if COMPILE_TEST
>  	default SOC_TYPE_XWAY
> diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile
> index 249ed35..cf23d38 100644
> --- a/drivers/reset/Makefile
> +++ b/drivers/reset/Makefile
> @@ -12,6 +12,7 @@ obj-$(CONFIG_RESET_BRCMSTB_RESCAL) += reset-brcmstb-rescal.o
>  obj-$(CONFIG_RESET_HSDK) += reset-hsdk.o
>  obj-$(CONFIG_RESET_IMX7) += reset-imx7.o
>  obj-$(CONFIG_RESET_INTEL_GW) += reset-intel-gw.o
> +obj-$(CONFIG_RESET_IMX_AUDIOMIX) += reset-imx-audiomix.o
>  obj-$(CONFIG_RESET_LANTIQ) += reset-lantiq.o
>  obj-$(CONFIG_RESET_LPC18XX) += reset-lpc18xx.o
>  obj-$(CONFIG_RESET_MESON) += reset-meson.o
> diff --git a/drivers/reset/reset-imx-audiomix.c b/drivers/reset/reset-imx-audiomix.c
> new file mode 100644
> index 00000000..d1c62ef
> --- /dev/null
> +++ b/drivers/reset/reset-imx-audiomix.c
> @@ -0,0 +1,122 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright 2019 NXP.
> + */
> +
> +#include <dt-bindings/reset/imx-audiomix-reset.h>
> +#include <linux/err.h>
> +#include <linux/io.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_address.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/reset-controller.h>
> +
> +#define IMX_AUDIOMIX_EARC_CTRL_REG	0x200
> +
> +#define IMX_AUDIOMIX_EARC_RESET_BIT	0x0
> +#define IMX_AUDIOMIX_EARC_PHY_RESET_BIT	0x1
> +
> +struct imx_audiomix_reset_data {
> +	void __iomem *base;
> +	struct reset_controller_dev rcdev;
> +	spinlock_t lock;
> +};
> +
> +static int imx_audiomix_reset_set(struct reset_controller_dev *rcdev,
> +			  unsigned long id, bool assert)
> +{
> +	struct imx_audiomix_reset_data *drvdata = container_of(rcdev,
> +			struct imx_audiomix_reset_data, rcdev);
> +	void __iomem *reg_addr = drvdata->base;
> +	unsigned long flags;
> +	unsigned int offset;
> +	u32 reg;
> +
> +	switch (id) {
> +	case IMX_AUDIOMIX_EARC_PHY_RESET:
> +		reg_addr += IMX_AUDIOMIX_EARC_CTRL_REG;
> +		offset = IMX_AUDIOMIX_EARC_PHY_RESET_BIT;
> +		break;
> +	case IMX_AUDIOMIX_EARC_RESET:
> +		reg_addr += IMX_AUDIOMIX_EARC_CTRL_REG;
> +		offset = IMX_AUDIOMIX_EARC_RESET_BIT;
> +		break;
> +	default:
> +		return -EINVAL;
> +	}
> +
> +	if (assert) {
> +		pm_runtime_get_sync(rcdev->dev);

This seems wrong. Why is the runtime PM reference count incremented when
a reset is asserted ...

> +		spin_lock_irqsave(&drvdata->lock, flags);
> +		reg = readl(reg_addr);
> +		writel(reg & ~BIT(offset), reg_addr);
> +		spin_unlock_irqrestore(&drvdata->lock, flags);
> +	} else {
> +		spin_lock_irqsave(&drvdata->lock, flags);
> +		reg = readl(reg_addr);
> +		writel(reg | BIT(offset), reg_addr);
> +		spin_unlock_irqrestore(&drvdata->lock, flags);
> +		pm_runtime_put(rcdev->dev);

... and decremented when a reset is deasserted?

Apart from the runtime PM handling this looks like it could reuse reset-
simple.

> +	}
> +
> +	return 0;
> +}
> +
> +static int imx_audiomix_reset_assert(struct reset_controller_dev *rcdev,
> +			     unsigned long id)
> +{
> +	return imx_audiomix_reset_set(rcdev, id, true);
> +}
> +
> +static int imx_audiomix_reset_deassert(struct reset_controller_dev *rcdev,
> +			       unsigned long id)
> +{
> +	return imx_audiomix_reset_set(rcdev, id, false);
> +}
> +
> +static const struct reset_control_ops imx_audiomix_reset_ops = {
> +	.assert		= imx_audiomix_reset_assert,
> +	.deassert	= imx_audiomix_reset_deassert,
> +};
> +
> +static int imx_audiomix_reset_probe(struct platform_device *pdev)
> +{
> +	struct imx_audiomix_reset_data *drvdata;
> +	struct device *dev = &pdev->dev;
> +
> +	drvdata = devm_kzalloc(&pdev->dev, sizeof(*drvdata), GFP_KERNEL);
> +	if (drvdata == NULL)
> +		return -ENOMEM;
> +
> +	drvdata->base = dev_get_drvdata(dev->parent);
> +
> +	platform_set_drvdata(pdev, drvdata);
> +
> +	pm_runtime_enable(dev);
> +
> +	spin_lock_init(&drvdata->lock);
> +
> +	drvdata->rcdev.owner     = THIS_MODULE;
> +	drvdata->rcdev.nr_resets = IMX_AUDIOMIX_RESET_NUM;
> +	drvdata->rcdev.ops       = &imx_audiomix_reset_ops;
> +	drvdata->rcdev.of_node   = dev->of_node;
> +	drvdata->rcdev.dev	 = dev;
> +
> +	return devm_reset_controller_register(dev, &drvdata->rcdev);
> +}
> +
> +static const struct of_device_id imx_audiomix_reset_dt_ids[] = {
> +	{ .compatible = "fsl,imx8mp-audiomix-reset", },
> +	{ /* sentinel */ },
> +};
> +
> +static struct platform_driver imx_audiomix_reset_driver = {
> +	.probe	= imx_audiomix_reset_probe,
> +	.driver = {
> +		.name		= KBUILD_MODNAME,
> +		.of_match_table	= imx_audiomix_reset_dt_ids,
> +	},
> +};
> +module_platform_driver(imx_audiomix_reset_driver);
> diff --git a/include/dt-bindings/reset/imx-audiomix-reset.h b/include/dt-bindings/reset/imx-audiomix-reset.h
> new file mode 100644
> index 00000000..2e26878
> --- /dev/null
> +++ b/include/dt-bindings/reset/imx-audiomix-reset.h
> @@ -0,0 +1,15 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright 2019 NXP.
> + */
> +
> +#ifndef DT_BINDING_RESET_IMX_AUDIOMIX_H
> +#define DT_BINDING_RESET_IMX_AUDIOMIX_H
> +
> +#define IMX_AUDIOMIX_EARC_RESET		0x0
> +#define IMX_AUDIOMIX_EARC_PHY_RESET	0x1
> +
> +#define IMX_AUDIOMIX_RESET_NUM		2
> +
> +#endif
> +

The imx-audiomix-reset.h change should go into a separate patch,
together with the binding docs for fsl,imx8mp-audiomix-reset.

regards
Philipp
Rob Herring March 10, 2020, 8:19 p.m. UTC | #2
On Tue, Mar 03, 2020 at 11:03:25AM +0200, Abel Vesa wrote:
> The imx-mix MFD driver registers some devices, one of which, in case of
> audiomix, maps correctly to a reset controller type. This driver registers
> a reset controller for that. For now, only the EARC specific resets are added.
> 
> Signed-off-by: Abel Vesa <abel.vesa@nxp.com>
> Reviewed-by: Leonard Crestez <leonard.crestez@nxp.com>
> ---
>  drivers/reset/Kconfig                          |   7 ++
>  drivers/reset/Makefile                         |   1 +
>  drivers/reset/reset-imx-audiomix.c             | 122 +++++++++++++++++++++++++
>  include/dt-bindings/reset/imx-audiomix-reset.h |  15 +++

This should be in a binding patch which makes me wonder where is the 
binding patch?

Rob
Abel Vesa March 13, 2020, 2:16 p.m. UTC | #3
On 20-03-04 12:41:33, Philipp Zabel wrote:
> Hi Abel,
> 
> On Tue, 2020-03-03 at 11:03 +0200, Abel Vesa wrote:
> > The imx-mix MFD driver registers some devices, one of which, in case of
> > audiomix, maps correctly to a reset controller type. This driver registers
> > a reset controller for that. For now, only the EARC specific resets are added.
> > 
> > Signed-off-by: Abel Vesa <abel.vesa@nxp.com>
> > Reviewed-by: Leonard Crestez <leonard.crestez@nxp.com>
> > ---
> >  drivers/reset/Kconfig                          |   7 ++
> >  drivers/reset/Makefile                         |   1 +
> >  drivers/reset/reset-imx-audiomix.c             | 122 +++++++++++++++++++++++++
> >  include/dt-bindings/reset/imx-audiomix-reset.h |  15 +++
> >  4 files changed, 145 insertions(+)
> >  create mode 100644 drivers/reset/reset-imx-audiomix.c
> >  create mode 100644 include/dt-bindings/reset/imx-audiomix-reset.h
> > 
> > diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig
> > index d9efbfd..2f8d9b3 100644
> > --- a/drivers/reset/Kconfig
> > +++ b/drivers/reset/Kconfig
> > @@ -81,6 +81,13 @@ config RESET_INTEL_GW
> >  	  Say Y to control the reset signals provided by reset controller.
> >  	  Otherwise, say N.
> >  
> > +config RESET_IMX_AUDIOMIX
> > +	bool "i.MX Audiomix Reset Driver" if COMPILE_TEST
> > +	depends on HAS_IOMEM
> > +	default ARCH_MXC
> > +	help
> > +	  This enables the audiomix reset controller driver for i.MX SoCs.
> > +
> >  config RESET_LANTIQ
> >  	bool "Lantiq XWAY Reset Driver" if COMPILE_TEST
> >  	default SOC_TYPE_XWAY
> > diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile
> > index 249ed35..cf23d38 100644
> > --- a/drivers/reset/Makefile
> > +++ b/drivers/reset/Makefile
> > @@ -12,6 +12,7 @@ obj-$(CONFIG_RESET_BRCMSTB_RESCAL) += reset-brcmstb-rescal.o
> >  obj-$(CONFIG_RESET_HSDK) += reset-hsdk.o
> >  obj-$(CONFIG_RESET_IMX7) += reset-imx7.o
> >  obj-$(CONFIG_RESET_INTEL_GW) += reset-intel-gw.o
> > +obj-$(CONFIG_RESET_IMX_AUDIOMIX) += reset-imx-audiomix.o
> >  obj-$(CONFIG_RESET_LANTIQ) += reset-lantiq.o
> >  obj-$(CONFIG_RESET_LPC18XX) += reset-lpc18xx.o
> >  obj-$(CONFIG_RESET_MESON) += reset-meson.o
> > diff --git a/drivers/reset/reset-imx-audiomix.c b/drivers/reset/reset-imx-audiomix.c
> > new file mode 100644
> > index 00000000..d1c62ef
> > --- /dev/null
> > +++ b/drivers/reset/reset-imx-audiomix.c
> > @@ -0,0 +1,122 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Copyright 2019 NXP.
> > + */
> > +
> > +#include <dt-bindings/reset/imx-audiomix-reset.h>
> > +#include <linux/err.h>
> > +#include <linux/io.h>
> > +#include <linux/module.h>
> > +#include <linux/of.h>
> > +#include <linux/of_address.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/pm_runtime.h>
> > +#include <linux/reset-controller.h>
> > +
> > +#define IMX_AUDIOMIX_EARC_CTRL_REG	0x200
> > +
> > +#define IMX_AUDIOMIX_EARC_RESET_BIT	0x0
> > +#define IMX_AUDIOMIX_EARC_PHY_RESET_BIT	0x1
> > +
> > +struct imx_audiomix_reset_data {
> > +	void __iomem *base;
> > +	struct reset_controller_dev rcdev;
> > +	spinlock_t lock;
> > +};
> > +
> > +static int imx_audiomix_reset_set(struct reset_controller_dev *rcdev,
> > +			  unsigned long id, bool assert)
> > +{
> > +	struct imx_audiomix_reset_data *drvdata = container_of(rcdev,
> > +			struct imx_audiomix_reset_data, rcdev);
> > +	void __iomem *reg_addr = drvdata->base;
> > +	unsigned long flags;
> > +	unsigned int offset;
> > +	u32 reg;
> > +
> > +	switch (id) {
> > +	case IMX_AUDIOMIX_EARC_PHY_RESET:
> > +		reg_addr += IMX_AUDIOMIX_EARC_CTRL_REG;
> > +		offset = IMX_AUDIOMIX_EARC_PHY_RESET_BIT;
> > +		break;
> > +	case IMX_AUDIOMIX_EARC_RESET:
> > +		reg_addr += IMX_AUDIOMIX_EARC_CTRL_REG;
> > +		offset = IMX_AUDIOMIX_EARC_RESET_BIT;
> > +		break;
> > +	default:
> > +		return -EINVAL;
> > +	}
> > +
> > +	if (assert) {
> > +		pm_runtime_get_sync(rcdev->dev);
> 
> This seems wrong. Why is the runtime PM reference count incremented when
> a reset is asserted ...

The audiomix IP has its own power domain. 

The way I see it, when the last deassert is done, there is no point
in keeping the audiomix on. So, unless the clock controller part of it does it,
the audiomix will be powered down.

> 
> > +		spin_lock_irqsave(&drvdata->lock, flags);
> > +		reg = readl(reg_addr);
> > +		writel(reg & ~BIT(offset), reg_addr);
> > +		spin_unlock_irqrestore(&drvdata->lock, flags);
> > +	} else {
> > +		spin_lock_irqsave(&drvdata->lock, flags);
> > +		reg = readl(reg_addr);
> > +		writel(reg | BIT(offset), reg_addr);
> > +		spin_unlock_irqrestore(&drvdata->lock, flags);
> > +		pm_runtime_put(rcdev->dev);
> 
> ... and decremented when a reset is deasserted?
> 
> Apart from the runtime PM handling this looks like it could reuse reset-
> simple.
> 
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +static int imx_audiomix_reset_assert(struct reset_controller_dev *rcdev,
> > +			     unsigned long id)
> > +{
> > +	return imx_audiomix_reset_set(rcdev, id, true);
> > +}
> > +
> > +static int imx_audiomix_reset_deassert(struct reset_controller_dev *rcdev,
> > +			       unsigned long id)
> > +{
> > +	return imx_audiomix_reset_set(rcdev, id, false);
> > +}
> > +
> > +static const struct reset_control_ops imx_audiomix_reset_ops = {
> > +	.assert		= imx_audiomix_reset_assert,
> > +	.deassert	= imx_audiomix_reset_deassert,
> > +};
> > +
> > +static int imx_audiomix_reset_probe(struct platform_device *pdev)
> > +{
> > +	struct imx_audiomix_reset_data *drvdata;
> > +	struct device *dev = &pdev->dev;
> > +
> > +	drvdata = devm_kzalloc(&pdev->dev, sizeof(*drvdata), GFP_KERNEL);
> > +	if (drvdata == NULL)
> > +		return -ENOMEM;
> > +
> > +	drvdata->base = dev_get_drvdata(dev->parent);
> > +
> > +	platform_set_drvdata(pdev, drvdata);
> > +
> > +	pm_runtime_enable(dev);
> > +
> > +	spin_lock_init(&drvdata->lock);
> > +
> > +	drvdata->rcdev.owner     = THIS_MODULE;
> > +	drvdata->rcdev.nr_resets = IMX_AUDIOMIX_RESET_NUM;
> > +	drvdata->rcdev.ops       = &imx_audiomix_reset_ops;
> > +	drvdata->rcdev.of_node   = dev->of_node;
> > +	drvdata->rcdev.dev	 = dev;
> > +
> > +	return devm_reset_controller_register(dev, &drvdata->rcdev);
> > +}
> > +
> > +static const struct of_device_id imx_audiomix_reset_dt_ids[] = {
> > +	{ .compatible = "fsl,imx8mp-audiomix-reset", },
> > +	{ /* sentinel */ },
> > +};
> > +
> > +static struct platform_driver imx_audiomix_reset_driver = {
> > +	.probe	= imx_audiomix_reset_probe,
> > +	.driver = {
> > +		.name		= KBUILD_MODNAME,
> > +		.of_match_table	= imx_audiomix_reset_dt_ids,
> > +	},
> > +};
> > +module_platform_driver(imx_audiomix_reset_driver);
> > diff --git a/include/dt-bindings/reset/imx-audiomix-reset.h b/include/dt-bindings/reset/imx-audiomix-reset.h
> > new file mode 100644
> > index 00000000..2e26878
> > --- /dev/null
> > +++ b/include/dt-bindings/reset/imx-audiomix-reset.h
> > @@ -0,0 +1,15 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Copyright 2019 NXP.
> > + */
> > +
> > +#ifndef DT_BINDING_RESET_IMX_AUDIOMIX_H
> > +#define DT_BINDING_RESET_IMX_AUDIOMIX_H
> > +
> > +#define IMX_AUDIOMIX_EARC_RESET		0x0
> > +#define IMX_AUDIOMIX_EARC_PHY_RESET	0x1
> > +
> > +#define IMX_AUDIOMIX_RESET_NUM		2
> > +
> > +#endif
> > +
> 
> The imx-audiomix-reset.h change should go into a separate patch,
> together with the binding docs for fsl,imx8mp-audiomix-reset.
> 
> regards
> Philipp
Philipp Zabel March 13, 2020, 3:55 p.m. UTC | #4
On Fri, 2020-03-13 at 16:16 +0200, Abel Vesa wrote:
[...]
> > > +	if (assert) {
> > > +		pm_runtime_get_sync(rcdev->dev);
> > 
> > This seems wrong. Why is the runtime PM reference count incremented when
> > a reset is asserted ...
> 
> The audiomix IP has its own power domain. 

The reset controller does not control the power domain for its
consumers. The consumer of this reset should implement runtime PM.

> The way I see it, when the last deassert is done, there is no point
> in keeping the audiomix on. So, unless the clock controller part of it does it,
> the audiomix will be powered down.

You mean when the last assert is done? Presumably the driver wants to
use the hardware after deasserting the reset and asserts the reset when
it is done.

regards
Philipp
Abel Vesa March 18, 2020, 11:08 a.m. UTC | #5
On 20-03-13 16:55:47, Philipp Zabel wrote:
> On Fri, 2020-03-13 at 16:16 +0200, Abel Vesa wrote:
> [...]
> > > > +	if (assert) {
> > > > +		pm_runtime_get_sync(rcdev->dev);
> > > 
> > > This seems wrong. Why is the runtime PM reference count incremented when
> > > a reset is asserted ...
> > 
> > The audiomix IP has its own power domain. 
> 
> The reset controller does not control the power domain for its
> consumers. The consumer of this reset should implement runtime PM.
> 

No, the reset controller itself is part of a more complex IP called audiomix
that has its own power domain.

> > The way I see it, when the last deassert is done, there is no point
> > in keeping the audiomix on. So, unless the clock controller part of it does it,
> > the audiomix will be powered down.
> 
> You mean when the last assert is done? Presumably the driver wants to
> use the hardware after deasserting the reset and asserts the reset when
> it is done.

No, I mean deassert. If there is no reset asserted anymore, then the audiomix
can power down, if nothing else (I'm talking about the other stuff that's
in the audiomix, like clock controller) keeping it on.

The reset controller needs to be on only when there is an assertion of at least
one reset bit going on.

> 
> regards
> Philipp

Patch
diff mbox series

diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig
index d9efbfd..2f8d9b3 100644
--- a/drivers/reset/Kconfig
+++ b/drivers/reset/Kconfig
@@ -81,6 +81,13 @@  config RESET_INTEL_GW
 	  Say Y to control the reset signals provided by reset controller.
 	  Otherwise, say N.
 
+config RESET_IMX_AUDIOMIX
+	bool "i.MX Audiomix Reset Driver" if COMPILE_TEST
+	depends on HAS_IOMEM
+	default ARCH_MXC
+	help
+	  This enables the audiomix reset controller driver for i.MX SoCs.
+
 config RESET_LANTIQ
 	bool "Lantiq XWAY Reset Driver" if COMPILE_TEST
 	default SOC_TYPE_XWAY
diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile
index 249ed35..cf23d38 100644
--- a/drivers/reset/Makefile
+++ b/drivers/reset/Makefile
@@ -12,6 +12,7 @@  obj-$(CONFIG_RESET_BRCMSTB_RESCAL) += reset-brcmstb-rescal.o
 obj-$(CONFIG_RESET_HSDK) += reset-hsdk.o
 obj-$(CONFIG_RESET_IMX7) += reset-imx7.o
 obj-$(CONFIG_RESET_INTEL_GW) += reset-intel-gw.o
+obj-$(CONFIG_RESET_IMX_AUDIOMIX) += reset-imx-audiomix.o
 obj-$(CONFIG_RESET_LANTIQ) += reset-lantiq.o
 obj-$(CONFIG_RESET_LPC18XX) += reset-lpc18xx.o
 obj-$(CONFIG_RESET_MESON) += reset-meson.o
diff --git a/drivers/reset/reset-imx-audiomix.c b/drivers/reset/reset-imx-audiomix.c
new file mode 100644
index 00000000..d1c62ef
--- /dev/null
+++ b/drivers/reset/reset-imx-audiomix.c
@@ -0,0 +1,122 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2019 NXP.
+ */
+
+#include <dt-bindings/reset/imx-audiomix-reset.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/reset-controller.h>
+
+#define IMX_AUDIOMIX_EARC_CTRL_REG	0x200
+
+#define IMX_AUDIOMIX_EARC_RESET_BIT	0x0
+#define IMX_AUDIOMIX_EARC_PHY_RESET_BIT	0x1
+
+struct imx_audiomix_reset_data {
+	void __iomem *base;
+	struct reset_controller_dev rcdev;
+	spinlock_t lock;
+};
+
+static int imx_audiomix_reset_set(struct reset_controller_dev *rcdev,
+			  unsigned long id, bool assert)
+{
+	struct imx_audiomix_reset_data *drvdata = container_of(rcdev,
+			struct imx_audiomix_reset_data, rcdev);
+	void __iomem *reg_addr = drvdata->base;
+	unsigned long flags;
+	unsigned int offset;
+	u32 reg;
+
+	switch (id) {
+	case IMX_AUDIOMIX_EARC_PHY_RESET:
+		reg_addr += IMX_AUDIOMIX_EARC_CTRL_REG;
+		offset = IMX_AUDIOMIX_EARC_PHY_RESET_BIT;
+		break;
+	case IMX_AUDIOMIX_EARC_RESET:
+		reg_addr += IMX_AUDIOMIX_EARC_CTRL_REG;
+		offset = IMX_AUDIOMIX_EARC_RESET_BIT;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	if (assert) {
+		pm_runtime_get_sync(rcdev->dev);
+		spin_lock_irqsave(&drvdata->lock, flags);
+		reg = readl(reg_addr);
+		writel(reg & ~BIT(offset), reg_addr);
+		spin_unlock_irqrestore(&drvdata->lock, flags);
+	} else {
+		spin_lock_irqsave(&drvdata->lock, flags);
+		reg = readl(reg_addr);
+		writel(reg | BIT(offset), reg_addr);
+		spin_unlock_irqrestore(&drvdata->lock, flags);
+		pm_runtime_put(rcdev->dev);
+	}
+
+	return 0;
+}
+
+static int imx_audiomix_reset_assert(struct reset_controller_dev *rcdev,
+			     unsigned long id)
+{
+	return imx_audiomix_reset_set(rcdev, id, true);
+}
+
+static int imx_audiomix_reset_deassert(struct reset_controller_dev *rcdev,
+			       unsigned long id)
+{
+	return imx_audiomix_reset_set(rcdev, id, false);
+}
+
+static const struct reset_control_ops imx_audiomix_reset_ops = {
+	.assert		= imx_audiomix_reset_assert,
+	.deassert	= imx_audiomix_reset_deassert,
+};
+
+static int imx_audiomix_reset_probe(struct platform_device *pdev)
+{
+	struct imx_audiomix_reset_data *drvdata;
+	struct device *dev = &pdev->dev;
+
+	drvdata = devm_kzalloc(&pdev->dev, sizeof(*drvdata), GFP_KERNEL);
+	if (drvdata == NULL)
+		return -ENOMEM;
+
+	drvdata->base = dev_get_drvdata(dev->parent);
+
+	platform_set_drvdata(pdev, drvdata);
+
+	pm_runtime_enable(dev);
+
+	spin_lock_init(&drvdata->lock);
+
+	drvdata->rcdev.owner     = THIS_MODULE;
+	drvdata->rcdev.nr_resets = IMX_AUDIOMIX_RESET_NUM;
+	drvdata->rcdev.ops       = &imx_audiomix_reset_ops;
+	drvdata->rcdev.of_node   = dev->of_node;
+	drvdata->rcdev.dev	 = dev;
+
+	return devm_reset_controller_register(dev, &drvdata->rcdev);
+}
+
+static const struct of_device_id imx_audiomix_reset_dt_ids[] = {
+	{ .compatible = "fsl,imx8mp-audiomix-reset", },
+	{ /* sentinel */ },
+};
+
+static struct platform_driver imx_audiomix_reset_driver = {
+	.probe	= imx_audiomix_reset_probe,
+	.driver = {
+		.name		= KBUILD_MODNAME,
+		.of_match_table	= imx_audiomix_reset_dt_ids,
+	},
+};
+module_platform_driver(imx_audiomix_reset_driver);
diff --git a/include/dt-bindings/reset/imx-audiomix-reset.h b/include/dt-bindings/reset/imx-audiomix-reset.h
new file mode 100644
index 00000000..2e26878
--- /dev/null
+++ b/include/dt-bindings/reset/imx-audiomix-reset.h
@@ -0,0 +1,15 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2019 NXP.
+ */
+
+#ifndef DT_BINDING_RESET_IMX_AUDIOMIX_H
+#define DT_BINDING_RESET_IMX_AUDIOMIX_H
+
+#define IMX_AUDIOMIX_EARC_RESET		0x0
+#define IMX_AUDIOMIX_EARC_PHY_RESET	0x1
+
+#define IMX_AUDIOMIX_RESET_NUM		2
+
+#endif
+