linux-kernel - Re: [RFC PATCH v2 1/5] clk: meson: axg: move reset controller's code to separate module

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Message-ID: <dde59dd2ef4da81528e31f65844e0b3f.sboyd@kernel.org>
Date: Tue, 09 Apr 2024 19:27:36 -0700
From: Stephen Boyd <sboyd@...nel.org>
To: Conor Dooley <conor@...nel.org>
Cc: Jan Dakinevich <jan.dakinevich@...utedevices.com>, Jerome Brunet <jbrunet@...libre.com>, Philipp Zabel <p.zabel@...gutronix.de>, Neil Armstrong <neil.armstrong@...aro.org>, Michael Turquette <mturquette@...libre.com>, Rob Herring <robh@...nel.org>, Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>, Conor Dooley <conor+dt@...nel.org>, Kevin Hilman <khilman@...libre.com>, Martin Blumenstingl <martin.blumenstingl@...glemail.com>, linux-amlogic@...ts.infradead.org, linux-clk@...r.kernel.org, devicetree@...r.kernel.org, linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org
Subject: Re: [RFC PATCH v2 1/5] clk: meson: axg: move reset controller's code to separate module

Quoting Conor Dooley (2024-04-09 05:05:37)
> On Mon, Apr 08, 2024 at 06:05:51PM +0100, Conor Dooley wrote:
> 
> > > > Seconded, the clk-mpfs/reset-mpfs and clk-starfive-jh7110-sys/reset-
> > > > starfive-jh7110 drivers are examples of this.
> > > > 
> > > > > The auxiliary device creation function can also be in the
> > > > > drivers/reset/ directory so that the clk driver calls some function
> > > > > to create and register the device.
> > > > 
> > > > I'm undecided about this, do you think mpfs_reset_controller_register()
> > > > and jh7110_reset_controller_register() should rather live with the
> > > > reset aux drivers in drivers/reset/ ?
> > > 
> > > Yes, and also mpfs_reset_read() and friends. We should pass the base
> > > iomem pointer and parent device to mpfs_reset_adev_alloc() instead and
> > > then move all that code into drivers/reset with some header file
> > > exported function to call. That way the clk driver hands over the data
> > > without having to implement half the implementation.
> > 
> > I'll todo list that :)
> 
> Something like the below?
> 
> -- >8 --
> From a12f281d2cb869bcd9a6ffc45d0c6a0d3aa2e9e2 Mon Sep 17 00:00:00 2001
> From: Conor Dooley <conor.dooley@...rochip.com>
> Date: Tue, 9 Apr 2024 11:54:34 +0100
> Subject: [PATCH] clock, reset: microchip: move all mpfs reset code to the
>  reset subsystem
> 
> <insert something here>
> 
> Signed-off-by: Conor Dooley <conor.dooley@...rochip.com>

Looks pretty good.

>  static const struct of_device_id mpfs_clk_of_match_table[] = {
> diff --git a/drivers/reset/reset-mpfs.c b/drivers/reset/reset-mpfs.c
> index 7f3fb2d472f4..27cd68b4ee81 100644
> --- a/drivers/reset/reset-mpfs.c
> +++ b/drivers/reset/reset-mpfs.c
> @@ -137,9 +139,67 @@ static int mpfs_reset_probe(struct auxiliary_device *adev,
>         return devm_reset_controller_register(dev, rcdev);
>  }
>  
> +static void mpfs_reset_unregister_adev(void *_adev)
> +{
> +       struct auxiliary_device *adev = _adev;
> +
> +       auxiliary_device_delete(adev);
> +       auxiliary_device_uninit(adev);
> +}
> +
> +static void mpfs_reset_adev_release(struct device *dev)
> +{
> +       struct auxiliary_device *adev = to_auxiliary_dev(dev);
> +
> +       kfree(adev);
> +}
> +
> +static struct auxiliary_device *mpfs_reset_adev_alloc(struct device *clk_dev)
> +{
> +       struct auxiliary_device *adev;
> +       int ret;
> +
> +       adev = kzalloc(sizeof(*adev), GFP_KERNEL);
> +       if (!adev)
> +               return ERR_PTR(-ENOMEM);
> +
> +       adev->name = "reset-mpfs";
> +       adev->dev.parent = clk_dev;
> +       adev->dev.release = mpfs_reset_adev_release;
> +       adev->id = 666u;
> +
> +       ret = auxiliary_device_init(adev);
> +       if (ret) {
> +               kfree(adev);
> +               return ERR_PTR(ret);
> +       }
> +
> +       return adev;
> +}
> +
> +int mpfs_reset_controller_register(struct device *clk_dev, void __iomem *base)
> +{
> +       struct auxiliary_device *adev;
> +       int ret;
> +
> +       mpfs_reset_addr = base;

Instead of a global this can be stashed in adev->dev.platform_data and
grabbed in the driver probe?

> +
> +       adev = mpfs_reset_adev_alloc(clk_dev);
> +       if (IS_ERR(adev))
> +               return PTR_ERR(adev);
> +
> +       ret = auxiliary_device_add(adev);
> +       if (ret) {
> +               auxiliary_device_uninit(adev);
> +               return ret;
> +       }
> +
> +       return devm_add_action_or_reset(clk_dev, mpfs_reset_unregister_adev, adev);
> +}
> +
>  static const struct auxiliary_device_id mpfs_reset_ids[] = {
>         {
> -               .name = "clk_mpfs.reset-mpfs",
> +               .name = "reset_mpfs.reset-mpfs",
>         },
>         { }
>  };
> diff --git a/include/soc/microchip/mpfs.h b/include/soc/microchip/mpfs.h
> index 09722f83b0ca..0b756bf5e9bd 100644
> --- a/include/soc/microchip/mpfs.h
> +++ b/include/soc/microchip/mpfs.h
> @@ -43,11 +43,11 @@ struct mtd_info *mpfs_sys_controller_get_flash(struct mpfs_sys_controller *mpfs_
>  #endif /* if IS_ENABLED(CONFIG_POLARFIRE_SOC_SYS_CTRL) */
>  
>  #if IS_ENABLED(CONFIG_MCHP_CLK_MPFS)
> -
> -u32 mpfs_reset_read(struct device *dev);
> -
> -void mpfs_reset_write(struct device *dev, u32 val);
> -
> +#if IS_ENABLED(CONFIG_RESET_CONTROLLER)
> +int mpfs_reset_controller_register(struct device *clk_dev, void __iomem *base);
> +#else
> +int mpfs_reset_controller_register(struct device *clk_dev, void* __iomem base) { return 0;}

static inline