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* [PATCH] phy: tegra: xusb: Fix per-pad high-speed termination calibration
@ 2026-03-04 10:26 Wei-Cheng Chen
  2026-03-24  9:11 ` Jon Hunter
  0 siblings, 1 reply; 2+ messages in thread
From: Wei-Cheng Chen @ 2026-03-04 10:26 UTC (permalink / raw)
  To: jckuo, vkoul, neil.armstrong, thierry.reding, jonathanh
  Cc: linux-phy, linux-tegra, linux-kernel, waynec, wtsai,
	Wei-Cheng Chen

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 {
-- 
2.43.0


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2026-03-04 10:26 [PATCH] phy: tegra: xusb: Fix per-pad high-speed termination calibration Wei-Cheng Chen
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