Re: [PATCH] phy: tegra: xusb: Fix per-pad high-speed termination calibration

Jon Hunter
2026-04-29T09:11:05Z

Hi Vinod,

On 17/04/2026 09:23, Jon Hunter wrote:
> Hi Vinod,
>
> On 24/03/2026 09:11, Jon Hunter wrote:
>>
>> On 04/03/2026 10:26, Wei-Cheng Chen wrote:
>>> From: Wayne Chang <waynec@nvidia.com>
>>>
>>> The existing code reads a single hs_term_range_adj value from bit field
>>> [10:7] of FUSE_SKU_CALIB_0 and applies it to all USB2 pads uniformly.
>>> However, on SoCs that support per-pad termination, each pad has its own
>>> hs_term_range_adj field: pad 0 in FUSE_SKU_CALIB_0[10:7], and pads 1-3
>>> in FUSE_USB_CALIB_EXT_0 at bit offsets [8:5], [12:9], and [16:13]
>>> respectively.
>>>
>>> Fix the calibration by reading per-pad values from the appropriate fuse
>>> registers. For SoCs that do not support per-pad termination, replicate
>>> pad 0's value to all pads to maintain existing behavior.
>>>
>>> Add a has_per_pad_term flag to the SoC data to indicate whether per-pad
>>> termination values are available in FUSE_USB_CALIB_EXT_0.
>>>
>>> Fixes: 1ef535c6ba8e ("phy: tegra: xusb: Add Tegra194 support")
>>> Cc: stable@vger.kernel.org
>>> Signed-off-by: Wayne Chang <waynec@nvidia.com>
>>> Signed-off-by: Wei-Cheng Chen <weichengc@nvidia.com>
>>> ---
>>>   drivers/phy/tegra/xusb-tegra186.c | 33 ++++++++++++++++++++++++-------
>>>   drivers/phy/tegra/xusb.h          |  1 +
>>>   2 files changed, 27 insertions(+), 7 deletions(-)
>>>
>>> diff --git a/drivers/phy/tegra/xusb-tegra186.c b/drivers/phy/tegra/
>>> xusb-tegra186.c
>>> index bec9616c4a2..4452e73fb82 100644
>>> --- a/drivers/phy/tegra/xusb-tegra186.c
>>> +++ b/drivers/phy/tegra/xusb-tegra186.c
>>> @@ -20,8 +20,8 @@
>>>   /* FUSE USB_CALIB registers */
>>>   #define HS_CURR_LEVEL_PADX_SHIFT(x)    ((x) ? (11 + (x - 1) * 6) : 0)
>>>   #define HS_CURR_LEVEL_PAD_MASK        0x3f
>>> -#define HS_TERM_RANGE_ADJ_SHIFT        7
>>> -#define HS_TERM_RANGE_ADJ_MASK        0xf
>>> +#define HS_TERM_RANGE_ADJ_PADX_SHIFT(x)    ((x) ? (5 + (x - 1) *
>>> 4) : 7)
>>> +#define HS_TERM_RANGE_ADJ_PAD_MASK    0xf
>>>   #define HS_SQUELCH_SHIFT        29
>>>   #define HS_SQUELCH_MASK            0x7
>>> @@ -253,7 +253,7 @@
>>>   struct tegra_xusb_fuse_calibration {
>>>       u32 *hs_curr_level;
>>>       u32 hs_squelch;
>>> -    u32 hs_term_range_adj;
>>> +    u32 *hs_term_range_adj;
>>>       u32 rpd_ctrl;
>>>   };
>>> @@ -930,7 +930,7 @@ static int tegra186_utmi_phy_power_on(struct phy
>>> *phy)
>>>       value = padctl_readl(padctl,
>>> XUSB_PADCTL_USB2_OTG_PADX_CTL1(index));
>>>       value &= ~TERM_RANGE_ADJ(~0);
>>> -    value |= TERM_RANGE_ADJ(priv->calib.hs_term_range_adj);
>>> +    value |= TERM_RANGE_ADJ(priv->calib.hs_term_range_adj[index]);
>>>       value &= ~RPD_CTRL(~0);
>>>       value |= RPD_CTRL(priv->calib.rpd_ctrl);
>>>       padctl_writel(padctl, value,
>>> XUSB_PADCTL_USB2_OTG_PADX_CTL1(index));
>>> @@ -1464,17 +1464,23 @@ static const char * const
>>> tegra186_usb3_functions[] = {
>>>   static int
>>>   tegra186_xusb_read_fuse_calibration(struct tegra186_xusb_padctl
>>> *padctl)
>>>   {
>>> +    const struct tegra_xusb_padctl_soc *soc = padctl->base.soc;
>>>       struct device *dev = padctl->base.dev;
>>>       unsigned int i, count;
>>>       u32 value, *level;
>>> +    u32 *hs_term_range_adj;
>>>       int err;
>>> -    count = padctl->base.soc->ports.usb2.count;
>>> +    count = soc->ports.usb2.count;
>>>       level = devm_kcalloc(dev, count, sizeof(u32), GFP_KERNEL);
>>>       if (!level)
>>>           return -ENOMEM;
>>> +    hs_term_range_adj = devm_kcalloc(dev, count, sizeof(u32),
>>> GFP_KERNEL);
>>> +    if (!hs_term_range_adj)
>>> +        return -ENOMEM;
>>> +
>>>       err = tegra_fuse_readl(TEGRA_FUSE_SKU_CALIB_0, &value);
>>>       if (err)
>>>           return dev_err_probe(dev, err,
>>> @@ -1490,8 +1496,8 @@ tegra186_xusb_read_fuse_calibration(struct
>>> tegra186_xusb_padctl *padctl)
>>>       padctl->calib.hs_squelch = (value >> HS_SQUELCH_SHIFT) &
>>>                       HS_SQUELCH_MASK;
>>> -    padctl->calib.hs_term_range_adj = (value >>
>>> HS_TERM_RANGE_ADJ_SHIFT) &
>>> -                        HS_TERM_RANGE_ADJ_MASK;
>>> +    hs_term_range_adj[0] = (value >> HS_TERM_RANGE_ADJ_PADX_SHIFT(0)) &
>>> +                HS_TERM_RANGE_ADJ_PAD_MASK;
>>>       err = tegra_fuse_readl(TEGRA_FUSE_USB_CALIB_EXT_0, &value);
>>>       if (err) {
>>> @@ -1503,6 +1509,17 @@ tegra186_xusb_read_fuse_calibration(struct
>>> tegra186_xusb_padctl *padctl)
>>>       padctl->calib.rpd_ctrl = (value >> RPD_CTRL_SHIFT) &
>>> RPD_CTRL_MASK;
>>> +    for (i = 1; i < count; i++) {
>>> +        if (soc->has_per_pad_term)
>>> +            hs_term_range_adj[i] =
>>> +                (value >> HS_TERM_RANGE_ADJ_PADX_SHIFT(i)) &
>>> +                HS_TERM_RANGE_ADJ_PAD_MASK;
>>> +        else
>>> +            hs_term_range_adj[i] = hs_term_range_adj[0];
>>> +    }
>>> +
>>> +    padctl->calib.hs_term_range_adj = hs_term_range_adj;
>>> +
>>>       return 0;
>>>   }
>>> @@ -1708,6 +1725,7 @@ const struct tegra_xusb_padctl_soc
>>> tegra194_xusb_padctl_soc = {
>>>       .num_supplies = ARRAY_SIZE(tegra194_xusb_padctl_supply_names),
>>>       .supports_gen2 = true,
>>>       .poll_trk_completed = true,
>>> +    .has_per_pad_term = true,
>>>   };
>>>   EXPORT_SYMBOL_GPL(tegra194_xusb_padctl_soc);
>>> @@ -1732,6 +1750,7 @@ const struct tegra_xusb_padctl_soc
>>> tegra234_xusb_padctl_soc = {
>>>       .trk_hw_mode = false,
>>>       .trk_update_on_idle = true,
>>>       .supports_lp_cfg_en = true,
>>> +    .has_per_pad_term = true,
>>>   };
>>>   EXPORT_SYMBOL_GPL(tegra234_xusb_padctl_soc);
>>>   #endif
>>> diff --git a/drivers/phy/tegra/xusb.h b/drivers/phy/tegra/xusb.h
>>> index d2b5f956513..810b410672f 100644
>>> --- a/drivers/phy/tegra/xusb.h
>>> +++ b/drivers/phy/tegra/xusb.h
>>> @@ -436,6 +436,7 @@ struct tegra_xusb_padctl_soc {
>>>       bool trk_hw_mode;
>>>       bool trk_update_on_idle;
>>>       bool supports_lp_cfg_en;
>>> +    bool has_per_pad_term;
>>>   };
>>>   struct tegra_xusb_padctl {
>>
>> Reviewed-by: Jon Hunter <jonathanh@nvidia.com>
>> Tested-by: Jon Hunter <jonathanh@nvidia.com>
>
> I guess this was missed for Linux v7.1. If you don't have any concerns
> can you pick this up for v7.2 once v7.1-rc1 is out?

OK to pick this up now? It would be great to get this into -next.

Thanks!
Jon

--
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