Re: [PATCH 2/3] scsi: ufs: spacemit: k3: Add UFS Host Controller driver

[Philipp Zabel]

On Do, 2026-07-02 at 02:31 +0000, Yixun Lan wrote:
> SpacemiT K3 SoC consist of UFS (Universal Flash Storage) Host Controller
> which has features compatible with JEDEC UFS 2.2, MIPI UniPro v1.61 and
> M-PHY v3.0 standard.
> 
> Signed-off-by: Yixun Lan <dlan@xxxxxxxxxx>
> ---
>  drivers/ufs/host/Kconfig        |  12 +
>  drivers/ufs/host/Makefile       |   1 +
>  drivers/ufs/host/ufs-spacemit.c | 931 ++++++++++++++++++++++++++++++++++++++++
>  drivers/ufs/host/ufs-spacemit.h |  90 ++++
>  4 files changed, 1034 insertions(+)
> 
[...]
> --- /dev/null
> +++ b/drivers/ufs/host/ufs-spacemit.c
> @@ -0,0 +1,931 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (c) 2026 SpacemiT (Hangzhou) Technology Co. Ltd
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/clk-provider.h>
> +#include <linux/delay.h>
> +#include <linux/io.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>

Missing #include <linux/reset.h> for
devm_reset_control_get_optional_exclusive_deasserted() below.
Don't rely on indirect includes.

[...]
> +/**
> + * ufs_spacemit_init - init phy and prepare clk
> + * @hba: host controller instance
> + */
> +static int ufs_spacemit_init(struct ufs_hba *hba)
> +{
> +	int err = 0;
> +	struct device *dev = hba->dev;
> +	struct ufs_spacemit_host *host;
> +
> +	host = devm_kzalloc(dev, sizeof(*host), GFP_KERNEL);
> +	if (!host)
> +		return -ENOMEM;
> +
> +	host->rst = devm_reset_control_get_optional_exclusive_deasserted(dev, NULL);

Why is this stored in struct ufs_spacemit_host at all? As far as I can
see it is never used again, so this could be a local variable.

[...]
> diff --git a/drivers/ufs/host/ufs-spacemit.h b/drivers/ufs/host/ufs-spacemit.h
> new file mode 100644
> index 000000000000..6ae3c263a360
> --- /dev/null
> +++ b/drivers/ufs/host/ufs-spacemit.h
> @@ -0,0 +1,90 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * SpacemiT UFS Host Controller driver
> + *
> + * Copyright (c) 2026 SpacemiT (Hangzhou) Technology Co. Ltd
> + */
> +
> +#ifndef _UFS_SPACEMIT_H_
> +#define _UFS_SPACEMIT_H_
> +
> +#include <linux/reset-controller.h>

Drop this, we are not implementing a reset controller driver here.

> +#include <linux/reset.h>

You could replace this with a struct reset_control forward declaration.
Or drop it ...

[...]
> +struct ufs_spacemit_host {
> +	struct ufs_hba *hba;
> +	struct ufs_pa_layer_attr dev_req_params;
> +	struct reset_control *rst;

... if you end up removing the rst field entirely.

regards
Philipp