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Date:   Thu, 26 Mar 2020 11:03:06 +0000
From:   Lee Jones <lee.jones@linaro.org>
To:     Abel Vesa <abel.vesa@nxp.com>
Cc:     Rob Herring <robh@kernel.org>, Shawn Guo <shawnguo@kernel.org>,
        Sascha Hauer <kernel@pengutronix.de>,
        Fabio Estevam <fabio.estevam@nxp.com>,
        Mike Turquette <mturquette@baylibre.com>,
        Stephen Boyd <sboyd@kernel.org>,
        Anson Huang <anson.huang@nxp.com>,
        Leonard Crestez <leonard.crestez@nxp.com>,
        Peng Fan <peng.fan@nxp.com>, Jacky Bai <ping.bai@nxp.com>,
        NXP Linux Team <linux-imx@nxp.com>,
        devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        linux-clk@vger.kernel.org
Subject: Re: [RFC 01/11] mfd: Add i.MX generic mix support
Message-ID: <20200326110306.GE603801@dell>
References: <1583226206-19758-1-git-send-email-abel.vesa@nxp.com>
 <1583226206-19758-2-git-send-email-abel.vesa@nxp.com>
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On Tue, 03 Mar 2020, Abel Vesa wrote:

> Some of the i.MX SoCs have a IP for interfacing the dedicated IPs with
> clocks, resets and interrupts, plus some other specific control registers.
> To allow the functionality to be split between drivers, this MFD driver is
> added that has only two purposes: register the devices and map the entire
> register addresses. Everything else is left to the dedicated drivers that will
> bind to the registered devices.
> 
> Signed-off-by: Abel Vesa <abel.vesa@nxp.com>
> ---
>  drivers/mfd/Kconfig   | 11 +++++++++++
>  drivers/mfd/Makefile  |  1 +
>  drivers/mfd/imx-mix.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 60 insertions(+)
>  create mode 100644 drivers/mfd/imx-mix.c
> 
> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
> index 3c547ed..3c89288 100644
> --- a/drivers/mfd/Kconfig
> +++ b/drivers/mfd/Kconfig
> @@ -460,6 +460,17 @@ config MFD_MX25_TSADC
>  	  i.MX25 processors. They consist of a conversion queue for general
>  	  purpose ADC and a queue for Touchscreens.
>  
> +config MFD_IMX_MIX
> +	tristate "NXP i.MX Generic Mix Control Driver"
> +	depends on OF || COMPILE_TEST
> +	help
> +	  Enable generic mixes support. On some i.MX platforms, there are
> +	  devices that are a mix of multiple functionalities like reset
> +	  controllers, clock controllers and some others. In order to split
> +	  those functionalities between the right drivers, this MFD populates
> +	  with virtual devices based on what's found in the devicetree node,
> +	  leaving the rest of the behavior control to the dedicated driver.
> +
>  config MFD_HI6421_PMIC
>  	tristate "HiSilicon Hi6421 PMU/Codec IC"
>  	depends on OF
> diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
> index f935d10..5b2ae5d 100644
> --- a/drivers/mfd/Makefile
> +++ b/drivers/mfd/Makefile
> @@ -113,6 +113,7 @@ obj-$(CONFIG_MFD_TWL4030_AUDIO)	+= twl4030-audio.o
>  obj-$(CONFIG_TWL6040_CORE)	+= twl6040.o
>  
>  obj-$(CONFIG_MFD_MX25_TSADC)	+= fsl-imx25-tsadc.o
> +obj-$(CONFIG_MFD_IMX_MIX)	+= imx-mix.o
>  
>  obj-$(CONFIG_MFD_MC13XXX)	+= mc13xxx-core.o
>  obj-$(CONFIG_MFD_MC13XXX_SPI)	+= mc13xxx-spi.o
> diff --git a/drivers/mfd/imx-mix.c b/drivers/mfd/imx-mix.c
> new file mode 100644
> index 00000000..d3f8c71
> --- /dev/null
> +++ b/drivers/mfd/imx-mix.c
> @@ -0,0 +1,48 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright 2019 NXP.
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/clk-provider.h>
> +#include <linux/err.h>
> +#include <linux/io.h>
> +#include <linux/module.h>
> +#include <linux/of_address.h>
> +#include <linux/spinlock.h>
> +#include <linux/types.h>
> +#include <linux/platform_device.h>
> +#include <linux/of_platform.h>
> +
> +#include <linux/mfd/core.h>
> +
> +static int imx_audiomix_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct resource *res;
> +	void __iomem *base;
> +
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	base = devm_ioremap_resource(dev, res);
> +	if (IS_ERR(base))
> +		return PTR_ERR(base);
> +
> +	dev_set_drvdata(dev, base);
> +
> +	return devm_of_platform_populate(dev);
> +}
> +
> +static const struct of_device_id imx_audiomix_of_match[] = {
> +	{ .compatible = "fsl,imx8mp-audiomix" },
> +	{ /* Sentinel */ },
> +};
> +MODULE_DEVICE_TABLE(of, imx_audiomix_of_match);

This needs DT binding documentation.

Do the sub-device memory ranges overlap?

> +static struct platform_driver imx_audiomix_driver = {
> +	.probe = imx_audiomix_probe,
> +	.driver = {
> +		.name = "imx-audiomix",
> +		.of_match_table = of_match_ptr(imx_audiomix_of_match),
> +	},
> +};
> +module_platform_driver(imx_audiomix_driver);

-- 
Lee Jones [李琼斯]
Linaro Services Technical Lead
Linaro.org │ Open source software for ARM SoCs
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