Re: [PATCH v6 4/6] phy: realtek: usb2: introduce reset controller struct

[Manivannan Sadhasivam]

On Wed, May 20, 2026 at 10:57:26PM +0500, Rustam Adilov wrote:
> In RTL9607C, there is so called "IP Enable Controller" which resemble
> reset controller with reset lines and is used for various things like
> USB, PCIE, GMAC and such.
> 
> Introduce the reset_control struct to this driver to handle deasserting
> usb2 phy reset line.
> 
> Make use of the function devm_reset_control_array_get_optional_exclusive()
> function to get the reset controller and since existing RTD SoCs don't
> specify the resets we can have a cleaner code.
> 
> Since the vendor usb driver developed by Realtek doesn't assert the reset
> line (or in their case clear the register bit), we can reasonably assume
> reset_control_assert is not needed here.
> 
> Co-developed-by: Michael Zavertkin <misha.zavertkin@xxxxxxx>
> Signed-off-by: Michael Zavertkin <misha.zavertkin@xxxxxxx>
> Signed-off-by: Rustam Adilov <adilov@xxxxxxxxxxx>
> ---
>  drivers/phy/realtek/phy-rtk-usb2.c | 16 ++++++++++++++++
>  1 file changed, 16 insertions(+)
> 
> diff --git a/drivers/phy/realtek/phy-rtk-usb2.c b/drivers/phy/realtek/phy-rtk-usb2.c
> index a9e29d2f7e6f..16c5fc3191de 100644
> --- a/drivers/phy/realtek/phy-rtk-usb2.c
> +++ b/drivers/phy/realtek/phy-rtk-usb2.c
> @@ -17,6 +17,7 @@
>  #include <linux/sys_soc.h>
>  #include <linux/mfd/syscon.h>
>  #include <linux/phy/phy.h>
> +#include <linux/reset.h>
>  #include <linux/usb.h>
>  
>  /* GUSB2PHYACCn register */
> @@ -130,6 +131,7 @@ struct rtk_phy {
>  	struct phy_cfg *phy_cfg;
>  	int num_phy;
>  	struct phy_parameter *phy_parameter;
> +	struct reset_control *phy_rst;
>  
>  	struct dentry *debug_dir;
>  };
> @@ -676,6 +678,15 @@ static int rtk_phy_init(struct phy *phy)
>  	if (!rtk_phy)
>  		return -EINVAL;
>  
> +	if (rtk_phy->phy_rst) {
> +		ret = reset_control_deassert(rtk_phy->phy_rst);
> +
> +		if (ret)
> +			return ret;
> +
> +		usleep_range(5000, 6000);
> +	}
> +
>  	for (i = 0; i < rtk_phy->num_phy; i++)
>  		ret = do_rtk_phy_init(rtk_phy, i);
>  
> @@ -1059,6 +1070,11 @@ static int rtk_usb2phy_probe(struct platform_device *pdev)
>  
>  	rtk_phy->num_phy = phy_cfg->num_phy;
>  
> +	rtk_phy->phy_rst = devm_reset_control_array_get_optional_exclusive(dev);

Why do you need to use devm_reset_control_array*() for a single reset line?

- Mani

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