phy: uniphier-pcie: Fix updating phy parameters

The current driver uses a value from register TEST_O as the original
value for register TEST_I, though, the value is overwritten by "param",
so there is a bug that the original value isn't no longer used.

The value of TEST_O[7:0] should be masked with "mask", replaced with
"param", and placed in the bitfield TESTI_DAT_MASK as new TEST_I value.

Fixes: c6d9b1324159 ("phy: socionext: add PCIe PHY driver support")
Signed-off-by: Kunihiko Hayashi <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Vinod Koul <[e-mail]>

drivers/phy/socionext/phy-uniphier-pcie.c

···
 #define PORT_SEL_1		FIELD_PREP(PORT_SEL_MASK, 1)
 
 #define PCL_PHY_TEST_I		0x2000
-#define PCL_PHY_TEST_O		0x2004
 #define TESTI_DAT_MASK		GENMASK(13, 6)
 #define TESTI_ADR_MASK		GENMASK(5, 1)
 #define TESTI_WR_EN		BIT(0)
+
+#define PCL_PHY_TEST_O		0x2004
+#define TESTO_DAT_MASK		GENMASK(7, 0)
 
 #define PCL_PHY_RESET		0x200c
 #define PCL_PHY_RESET_N_MNMODE	BIT(8)	/* =1:manual */
···
 	val  = FIELD_PREP(TESTI_DAT_MASK, 1);
 	val |= FIELD_PREP(TESTI_ADR_MASK, reg);
 	uniphier_pciephy_testio_write(priv, val);
-	val = readl(priv->base + PCL_PHY_TEST_O);
+	val = readl(priv->base + PCL_PHY_TEST_O) & TESTO_DAT_MASK;
 
 	/* update value */
-	val &= ~FIELD_PREP(TESTI_DAT_MASK, mask);
-	val  = FIELD_PREP(TESTI_DAT_MASK, mask & param);
+	val &= ~mask;
+	val |= mask & param;
+	val = FIELD_PREP(TESTI_DAT_MASK, val);
 	val |= FIELD_PREP(TESTI_ADR_MASK, reg);
 	uniphier_pciephy_testio_write(priv, val);
 	uniphier_pciephy_testio_write(priv, val | TESTI_WR_EN);