Re: [PATCH v9 04/12] reset: realtek: Add RTD1625-ISO reset controller driver
From: Philipp Zabel
Date: Wed Jun 24 2026 - 09:04:18 EST
On Mi, 2026-06-24 at 19:29 +0800, Yu-Chun Lin wrote:
> From: Cheng-Yu Lee <cylee12@xxxxxxxxxxx>
>
> Add support for the ISO (Isolation) domain reset controller on the Realtek
> RTD1625 SoC.
>
> The reset controller shares the same register space with the ISO clock
> controller. To handle this shared register space, the reset driver is
> implemented as an auxiliary driver. It will be instantiated and probed via
> the auxiliary bus by the RTD1625-ISO clock controller driver.
>
> Signed-off-by: Cheng-Yu Lee <cylee12@xxxxxxxxxxx>
> Co-developed-by: Yu-Chun Lin <eleanor.lin@xxxxxxxxxxx>
> Signed-off-by: Yu-Chun Lin <eleanor.lin@xxxxxxxxxxx>
> ---
> Changes in v9:
> - Extract reset-related code from the previous clock driver patch
> (formerly patch 9 in v8).
> ---
> drivers/reset/realtek/Makefile | 2 +-
> drivers/reset/realtek/reset-rtd1625-iso.c | 99 +++++++++++++++++++++++
> 2 files changed, 100 insertions(+), 1 deletion(-)
> create mode 100644 drivers/reset/realtek/reset-rtd1625-iso.c
>
> diff --git a/drivers/reset/realtek/Makefile b/drivers/reset/realtek/Makefile
> index c3f605ffb11c..9007c9d5683b 100644
> --- a/drivers/reset/realtek/Makefile
> +++ b/drivers/reset/realtek/Makefile
> @@ -1,3 +1,3 @@
> # SPDX-License-Identifier: GPL-2.0-only
> obj-$(CONFIG_RESET_RTK_COMMON) += reset-rtk-common.o
> -obj-$(CONFIG_RESET_RTD1625) += reset-rtd1625-crt.o
> +obj-$(CONFIG_RESET_RTD1625) += reset-rtd1625-crt.o reset-rtd1625-iso.o
Is there any benefit to these two being separate modules?
I suggest you merge them into one: reset-rtd1625.o
> diff --git a/drivers/reset/realtek/reset-rtd1625-iso.c b/drivers/reset/realtek/reset-rtd1625-iso.c
> new file mode 100644
> index 000000000000..78eaabb408f0
> --- /dev/null
> +++ b/drivers/reset/realtek/reset-rtd1625-iso.c
> @@ -0,0 +1,99 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (C) 2026 Realtek Semiconductor Corporation
> + */
> +
> +#include <dt-bindings/reset/realtek,rtd1625.h>
> +#include <linux/auxiliary_bus.h>
> +#include <linux/device.h>
> +#include <linux/errno.h>
> +#include <linux/of.h>
> +#include <linux/slab.h>
> +#include "reset-rtk-common.h"
> +
> +#define RTD1625_ISO_RSTN_MAX 29
> +#define RTD1625_ISO_S_RSTN_MAX 5
These are not necessary, just use ARRAY_SIZE() for nr_resets.
> +
> +static const struct rtk_reset_desc rtd1625_iso_reset_descs[] = {
> + [RTD1625_ISO_RSTN_VFD] = { .ofs = 0x88, .bit = 0 },
> + [RTD1625_ISO_RSTN_CEC0] = { .ofs = 0x88, .bit = 2 },
> + [RTD1625_ISO_RSTN_CEC1] = { .ofs = 0x88, .bit = 3 },
> + [RTD1625_ISO_RSTN_CBUSTX] = { .ofs = 0x88, .bit = 5 },
> + [RTD1625_ISO_RSTN_CBUSRX] = { .ofs = 0x88, .bit = 6 },
> + [RTD1625_ISO_RSTN_USB3_PHY2_XTAL_POW] = { .ofs = 0x88, .bit = 7 },
> + [RTD1625_ISO_RSTN_UR0] = { .ofs = 0x88, .bit = 8 },
> + [RTD1625_ISO_RSTN_GMAC] = { .ofs = 0x88, .bit = 9 },
> + [RTD1625_ISO_RSTN_GPHY] = { .ofs = 0x88, .bit = 10 },
> + [RTD1625_ISO_RSTN_I2C_0] = { .ofs = 0x88, .bit = 11 },
> + [RTD1625_ISO_RSTN_I2C_1] = { .ofs = 0x88, .bit = 12 },
> + [RTD1625_ISO_RSTN_CBUS] = { .ofs = 0x88, .bit = 13 },
> + [RTD1625_ISO_RSTN_USB_DRD] = { .ofs = 0x88, .bit = 14 },
> + [RTD1625_ISO_RSTN_USB_HOST] = { .ofs = 0x88, .bit = 15 },
> + [RTD1625_ISO_RSTN_USB_PHY_0] = { .ofs = 0x88, .bit = 16 },
> + [RTD1625_ISO_RSTN_USB_PHY_1] = { .ofs = 0x88, .bit = 17 },
> + [RTD1625_ISO_RSTN_USB_PHY_2] = { .ofs = 0x88, .bit = 18 },
> + [RTD1625_ISO_RSTN_USB] = { .ofs = 0x88, .bit = 19 },
> + [RTD1625_ISO_RSTN_TYPE_C] = { .ofs = 0x88, .bit = 20 },
> + [RTD1625_ISO_RSTN_USB_U3_HOST] = { .ofs = 0x88, .bit = 21 },
> + [RTD1625_ISO_RSTN_USB3_PHY0_POW] = { .ofs = 0x88, .bit = 22 },
> + [RTD1625_ISO_RSTN_USB3_P0_MDIO] = { .ofs = 0x88, .bit = 23 },
> + [RTD1625_ISO_RSTN_USB3_PHY1_POW] = { .ofs = 0x88, .bit = 24 },
> + [RTD1625_ISO_RSTN_USB3_P1_MDIO] = { .ofs = 0x88, .bit = 25 },
> + [RTD1625_ISO_RSTN_VTC] = { .ofs = 0x88, .bit = 26 },
> + [RTD1625_ISO_RSTN_USB3_PHY2_POW] = { .ofs = 0x88, .bit = 27 },
> + [RTD1625_ISO_RSTN_USB3_P2_MDIO] = { .ofs = 0x88, .bit = 28 },
> + [RTD1625_ISO_RSTN_USB_PHY_3] = { .ofs = 0x88, .bit = 29 },
> + [RTD1625_ISO_RSTN_USB_PHY_4] = { .ofs = 0x88, .bit = 30 },
> +};
> +
> +static const struct rtk_reset_desc rtd1625_iso_s_reset_descs[] = {
> + [RTD1625_ISO_S_RSTN_ISOM_MIS] = { .ofs = 0x310, .bit = 0, .write_en = 1 },
> + [RTD1625_ISO_S_RSTN_GPIOM] = { .ofs = 0x310, .bit = 2, .write_en = 1 },
> + [RTD1625_ISO_S_RSTN_TIMER7] = { .ofs = 0x310, .bit = 4, .write_en = 1 },
> + [RTD1625_ISO_S_RSTN_IRDA] = { .ofs = 0x310, .bit = 6, .write_en = 1 },
> + [RTD1625_ISO_S_RSTN_UR10] = { .ofs = 0x310, .bit = 8, .write_en = 1 },
> +};
> +
> +static int rtd1625_iso_reset_probe(struct auxiliary_device *adev,
> + const struct auxiliary_device_id *id)
> +{
> + struct device *dev = &adev->dev;
> + struct device *parent = dev->parent;
> + struct rtk_reset_data *data;
> +
> + data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
> + if (!data)
> + return -ENOMEM;
> +
> + if (of_device_is_compatible(parent->of_node, "realtek,rtd1625-iso-s-clk")) {
> + data->descs = rtd1625_iso_s_reset_descs;
> + data->rcdev.nr_resets = RTD1625_ISO_S_RSTN_MAX;
> + } else {
> + data->descs = rtd1625_iso_reset_descs;
> + data->rcdev.nr_resets = RTD1625_ISO_RSTN_MAX;
> + }
No need to parse OF compatible again. Store these in a struct, point
auxiliary_device_id::driver_data to it, and use that here.
regards
Philipp