Re: [PATCH v3 2/6] reset: imx8mp-audiomix: Add AudioMix Block Control reset driver

[Frank Li <Frank.li@nxp.com>]

On Tue, May 14, 2024 at 05:33:26PM +0800, Shengjiu Wang wrote:
> Audiomix block control can be a reset controller for
> Enhanced Audio Return Channel (EARC), which is one of
> modules in this audiomix subsystem.
> 
> The EARC PHY software reset and EARC controller software
> reset need to be supported.
> 
> Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
> ---
>  drivers/reset/Kconfig                 |   8 ++
>  drivers/reset/Makefile                |   1 +
>  drivers/reset/reset-imx8mp-audiomix.c | 117 ++++++++++++++++++++++++++

It is just some bit change. Can you reuse reset-ti-syscon.c ? 

Frank

>  3 files changed, 126 insertions(+)
>  create mode 100644 drivers/reset/reset-imx8mp-audiomix.c
> 
> diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig
> index 7112f5932609..0e7da0bb0a21 100644
> --- a/drivers/reset/Kconfig
> +++ b/drivers/reset/Kconfig
> @@ -91,6 +91,14 @@ config RESET_IMX7
>  	help
>  	  This enables the reset controller driver for i.MX7 SoCs.
>  
> +config RESET_IMX8MP_AUDIOMIX
> +	tristate "i.MX8MP AudioMix Reset Driver"
> +	depends on HAS_IOMEM
> +	depends on (ARM64 && ARCH_MXC) || COMPILE_TEST
> +	select MFD_SYSCON
> +	help
> +	  This enables the reset controller driver for i.MX8MP AudioMix.
> +
>  config RESET_INTEL_GW
>  	bool "Intel Reset Controller Driver"
>  	depends on X86 || COMPILE_TEST
> diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile
> index fd8b49fa46fc..a6796e83900b 100644
> --- a/drivers/reset/Makefile
> +++ b/drivers/reset/Makefile
> @@ -14,6 +14,7 @@ obj-$(CONFIG_RESET_BRCMSTB_RESCAL) += reset-brcmstb-rescal.o
>  obj-$(CONFIG_RESET_GPIO) += reset-gpio.o
>  obj-$(CONFIG_RESET_HSDK) += reset-hsdk.o
>  obj-$(CONFIG_RESET_IMX7) += reset-imx7.o
> +obj-$(CONFIG_RESET_IMX8MP_AUDIOMIX) += reset-imx8mp-audiomix.o
>  obj-$(CONFIG_RESET_INTEL_GW) += reset-intel-gw.o
>  obj-$(CONFIG_RESET_K210) += reset-k210.o
>  obj-$(CONFIG_RESET_LANTIQ) += reset-lantiq.o
> diff --git a/drivers/reset/reset-imx8mp-audiomix.c b/drivers/reset/reset-imx8mp-audiomix.c
> new file mode 100644
> index 000000000000..8ba0d4406b36
> --- /dev/null
> +++ b/drivers/reset/reset-imx8mp-audiomix.c
> @@ -0,0 +1,117 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Copyright 2024 NXP
> + */
> +
> +#include <linux/mfd/syscon.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/regmap.h>
> +#include <linux/reset-controller.h>
> +
> +#define EARC			0x200
> +#define EARC_RESET_MASK		0x3
> +
> +struct imx8mp_audiomix_rst_priv {
> +	struct regmap *regmap;
> +	struct reset_controller_dev rcdev;
> +};
> +
> +static int imx8mp_audiomix_reset_set(struct reset_controller_dev *rcdev,
> +				     unsigned long id, bool assert)
> +{
> +	struct imx8mp_audiomix_rst_priv *priv = container_of(rcdev,
> +				struct imx8mp_audiomix_rst_priv, rcdev);
> +	unsigned int mask = BIT(id);
> +
> +	/* bit = 0 reset, bit = 1 unreset */
> +	if (assert)
> +		regmap_update_bits(priv->regmap, EARC, mask, 0);
> +	else
> +		regmap_update_bits(priv->regmap, EARC, mask, mask);
> +
> +	return 0;
> +}
> +
> +static int imx8mp_audiomix_reset_reset(struct reset_controller_dev *rcdev,
> +				       unsigned long id)
> +{
> +	imx8mp_audiomix_reset_set(rcdev, id, true);
> +
> +	return imx8mp_audiomix_reset_set(rcdev, id, false);
> +}
> +
> +static int imx8mp_audiomix_reset_assert(struct reset_controller_dev *rcdev,
> +					unsigned long id)
> +{
> +	return imx8mp_audiomix_reset_set(rcdev, id, true);
> +}
> +
> +static int imx8mp_audiomix_reset_deassert(struct reset_controller_dev *rcdev,
> +					  unsigned long id)
> +{
> +	return imx8mp_audiomix_reset_set(rcdev, id, false);
> +}
> +
> +static int imx8mp_audiomix_reset_xlate(struct reset_controller_dev *rcdev,
> +				       const struct of_phandle_args *reset_spec)
> +{
> +	unsigned long id = reset_spec->args[0];
> +
> +	if (!(BIT(id) & EARC_RESET_MASK))
> +		return -EINVAL;
> +
> +	return id;
> +}
> +
> +static const struct reset_control_ops imx8mp_audiomix_reset_ops = {
> +	.reset = imx8mp_audiomix_reset_reset,
> +	.assert = imx8mp_audiomix_reset_assert,
> +	.deassert = imx8mp_audiomix_reset_deassert,
> +};
> +
> +static int imx8mp_audiomix_reset_probe(struct platform_device *pdev)
> +{
> +	struct device_node *parent_np = of_get_parent(pdev->dev.of_node);
> +	struct imx8mp_audiomix_rst_priv *priv;
> +
> +	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
> +	if (!priv)
> +		return -ENOMEM;
> +
> +	priv->regmap = syscon_node_to_regmap(parent_np);
> +	of_node_put(parent_np);
> +	if (IS_ERR(priv->regmap))
> +		return PTR_ERR(priv->regmap);
> +
> +	priv->rcdev.owner     = THIS_MODULE;
> +	priv->rcdev.nr_resets = fls(EARC_RESET_MASK);
> +	priv->rcdev.ops       = &imx8mp_audiomix_reset_ops;
> +	priv->rcdev.of_node   = pdev->dev.of_node;
> +	priv->rcdev.dev	      = &pdev->dev;
> +	priv->rcdev.of_reset_n_cells = 1;
> +	priv->rcdev.of_xlate  = imx8mp_audiomix_reset_xlate;
> +
> +	return devm_reset_controller_register(&pdev->dev, &priv->rcdev);
> +}
> +
> +static const struct of_device_id imx8mp_audiomix_reset_dt_match[] = {
> +	{ .compatible = "fsl,imx8mp-audiomix-reset" },
> +	{ /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, imx8mp_audiomix_reset_dt_match);
> +
> +static struct platform_driver imx8mp_audiomix_reset_driver = {
> +	.probe	= imx8mp_audiomix_reset_probe,
> +	.driver	= {
> +		.name = "imx8mp-audiomix-reset",
> +		.of_match_table = imx8mp_audiomix_reset_dt_match,
> +	},
> +};
> +module_platform_driver(imx8mp_audiomix_reset_driver);
> +
> +MODULE_AUTHOR("Shengjiu Wang <shengjiu.wang@nxp.com>");
> +MODULE_DESCRIPTION("Freescale i.MX8MP Audio Block Controller reset driver");
> +MODULE_LICENSE("GPL");
> -- 
> 2.34.1
>