Re: [PATCH v26 2/3] reset: npcm: register npcm8xx clock auxiliary bus device

[Benjamin Fair]

On Tue, 2 Jul 2024 at 12:17, Tomer Maimon <tmaimon77@xxxxxxxxx> wrote:
>
> Add NPCM8xx clock controller auxiliary bus device registration.
>
> The NPCM8xx clock controller is registered as an aux device because the
> reset and the clock controller share the same register region.
>
> Signed-off-by: Tomer Maimon <tmaimon77@xxxxxxxxx>

I booted a kernel with this driver and verified that basic
functionality works fine.

Tested-by: Benjamin Fair <benjaminfair@xxxxxxxxxx>

> ---
>  drivers/reset/Kconfig               |  1 +
>  drivers/reset/reset-npcm.c          | 74 ++++++++++++++++++++++++++++-
>  include/soc/nuvoton/clock-npcm8xx.h | 16 +++++++
>  3 files changed, 90 insertions(+), 1 deletion(-)
>  create mode 100644 include/soc/nuvoton/clock-npcm8xx.h
>
> diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig
> index 7112f5932609..31ec8795c105 100644
> --- a/drivers/reset/Kconfig
> +++ b/drivers/reset/Kconfig
> @@ -148,6 +148,7 @@ config RESET_MESON_AUDIO_ARB
>  config RESET_NPCM
>         bool "NPCM BMC Reset Driver" if COMPILE_TEST
>         default ARCH_NPCM
> +       select AUXILIARY_BUS
>         help
>           This enables the reset controller driver for Nuvoton NPCM
>           BMC SoCs.
> diff --git a/drivers/reset/reset-npcm.c b/drivers/reset/reset-npcm.c
> index 8935ef95a2d1..aa68b947226a 100644
> --- a/drivers/reset/reset-npcm.c
> +++ b/drivers/reset/reset-npcm.c
> @@ -1,6 +1,7 @@
>  // SPDX-License-Identifier: GPL-2.0
>  // Copyright (c) 2019 Nuvoton Technology corporation.
>
> +#include <linux/auxiliary_bus.h>
>  #include <linux/delay.h>
>  #include <linux/err.h>
>  #include <linux/io.h>
> @@ -10,11 +11,14 @@
>  #include <linux/property.h>
>  #include <linux/reboot.h>
>  #include <linux/reset-controller.h>
> +#include <linux/slab.h>
>  #include <linux/spinlock.h>
>  #include <linux/mfd/syscon.h>
>  #include <linux/regmap.h>
>  #include <linux/of_address.h>
>
> +#include <soc/nuvoton/clock-npcm8xx.h>
> +
>  /* NPCM7xx GCR registers */
>  #define NPCM_MDLR_OFFSET       0x7C
>  #define NPCM7XX_MDLR_USBD0     BIT(9)
> @@ -89,6 +93,7 @@ struct npcm_rc_data {
>         const struct npcm_reset_info *info;
>         struct regmap *gcr_regmap;
>         u32 sw_reset_number;
> +       struct device *dev;
>         void __iomem *base;
>         spinlock_t lock;
>  };
> @@ -372,6 +377,67 @@ static const struct reset_control_ops npcm_rc_ops = {
>         .status         = npcm_rc_status,
>  };
>
> +static void npcm_clock_unregister_adev(void *_adev)
> +{
> +       struct auxiliary_device *adev = _adev;
> +
> +       auxiliary_device_delete(adev);
> +       auxiliary_device_uninit(adev);
> +}
> +
> +static void npcm_clock_adev_release(struct device *dev)
> +{
> +       struct auxiliary_device *adev = to_auxiliary_dev(dev);
> +       struct npcm_clock_adev *rdev = to_npcm_clock_adev(adev);
> +
> +       kfree(rdev);
> +}
> +
> +static struct auxiliary_device *npcm_clock_adev_alloc(struct npcm_rc_data *rst_data, char *clk_name)
> +{
> +       struct npcm_clock_adev *rdev;
> +       struct auxiliary_device *adev;
> +       int ret;
> +
> +       rdev = kzalloc(sizeof(*rdev), GFP_KERNEL);
> +       if (!rdev)
> +               return ERR_PTR(-ENOMEM);
> +
> +       rdev->base = rst_data->base;
> +
> +       adev = &rdev->adev;
> +       adev->name = clk_name;
> +       adev->dev.parent = rst_data->dev;
> +       adev->dev.release = npcm_clock_adev_release;
> +       adev->id = 555u;
> +
> +       ret = auxiliary_device_init(adev);
> +       if (ret) {
> +               kfree(rdev);
> +               return ERR_PTR(ret);
> +       }
> +
> +       return adev;
> +}
> +
> +static int npcm8xx_clock_controller_register(struct npcm_rc_data *rst_data, char *clk_name)
> +{
> +       struct auxiliary_device *adev;
> +       int ret;
> +
> +       adev = npcm_clock_adev_alloc(rst_data, clk_name);
> +       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(rst_data->dev, npcm_clock_unregister_adev, adev);
> +}
> +
>  static int npcm_rc_probe(struct platform_device *pdev)
>  {
>         struct npcm_rc_data *rc;
> @@ -392,6 +458,7 @@ static int npcm_rc_probe(struct platform_device *pdev)
>         rc->rcdev.of_node = pdev->dev.of_node;
>         rc->rcdev.of_reset_n_cells = 2;
>         rc->rcdev.of_xlate = npcm_reset_xlate;
> +       rc->dev = &pdev->dev;
>
>         ret = devm_reset_controller_register(&pdev->dev, &rc->rcdev);
>         if (ret) {
> @@ -413,7 +480,12 @@ static int npcm_rc_probe(struct platform_device *pdev)
>                 }
>         }
>
> -       return ret;
> +       switch (rc->info->bmc_id) {
> +       case BMC_NPCM8XX:
> +               return npcm8xx_clock_controller_register(rc, "clk-npcm8xx");
> +       default:
> +               return ret;
> +       }
>  }
>
>  static struct platform_driver npcm_rc_driver = {
> diff --git a/include/soc/nuvoton/clock-npcm8xx.h b/include/soc/nuvoton/clock-npcm8xx.h
> new file mode 100644
> index 000000000000..139130e98c51
> --- /dev/null
> +++ b/include/soc/nuvoton/clock-npcm8xx.h
> @@ -0,0 +1,16 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#ifndef __SOC_NPCM8XX_CLOCK_H
> +#define __SOC_NPCM8XX_CLOCK_H
> +
> +#include <linux/auxiliary_bus.h>
> +#include <linux/container_of.h>
> +
> +struct npcm_clock_adev {
> +       void __iomem *base;
> +       struct auxiliary_device adev;
> +};
> +
> +#define to_npcm_clock_adev(_adev) \
> +       container_of((_adev), struct npcm_clock_adev, adev)
> +
> +#endif
> --
> 2.34.1
>