[PATCH v2 3/4] phy: qualcomm: phy-qcom-eusb2-repeater: Zero out untouched tuning regs

[Konrad Dybcio]

The vendor kernel zeroes out all tuning data outside the init sequence
as part of initialization. Follow suit to avoid UB.

Signed-off-by: Konrad Dybcio <konrad.dybcio at linaro.org>
---
 drivers/phy/qualcomm/phy-qcom-eusb2-repeater.c | 58 +++++++++++++++++++-------
 1 file changed, 44 insertions(+), 14 deletions(-)

diff --git a/drivers/phy/qualcomm/phy-qcom-eusb2-repeater.c b/drivers/phy/qualcomm/phy-qcom-eusb2-repeater.c
index 7561da01e633..d4fb85c20eb0 100644
--- a/drivers/phy/qualcomm/phy-qcom-eusb2-repeater.c
+++ b/drivers/phy/qualcomm/phy-qcom-eusb2-repeater.c
@@ -24,9 +24,18 @@
 #define EUSB2_FORCE_VAL_5		0xeD
 #define V_CLK_19P2M_EN			BIT(6)
 
+#define EUSB2_TUNE_USB2_CROSSOVER	0x50
 #define EUSB2_TUNE_IUSB2		0x51
+#define EUSB2_TUNE_RES_FSDIF		0x52
+#define EUSB2_TUNE_HSDISC		0x53
 #define EUSB2_TUNE_SQUELCH_U		0x54
+#define EUSB2_TUNE_USB2_SLEW		0x55
+#define EUSB2_TUNE_USB2_EQU		0x56
 #define EUSB2_TUNE_USB2_PREEM		0x57
+#define EUSB2_TUNE_USB2_HS_COMP_CUR	0x58
+#define EUSB2_TUNE_EUSB_SLEW		0x59
+#define EUSB2_TUNE_EUSB_EQU		0x5A
+#define EUSB2_TUNE_EUSB_HS_COMP_CUR	0x5B
 
 #define QCOM_EUSB2_REPEATER_INIT_CFG(r, v)	\
 	{					\
@@ -35,9 +44,18 @@
 	}
 
 enum reg_fields {
+	F_TUNE_EUSB_HS_COMP_CUR,
+	F_TUNE_EUSB_EQU,
+	F_TUNE_EUSB_SLEW,
+	F_TUNE_USB2_HS_COMP_CUR,
 	F_TUNE_USB2_PREEM,
+	F_TUNE_USB2_EQU,
+	F_TUNE_USB2_SLEW,
 	F_TUNE_SQUELCH_U,
+	F_TUNE_HSDISC,
+	F_TUNE_RES_FSDIF,
 	F_TUNE_IUSB2,
+	F_TUNE_USB2_CROSSOVER,
 	F_NUM_TUNE_FIELDS,
 
 	F_FORCE_VAL_5 = F_NUM_TUNE_FIELDS,
@@ -50,9 +68,18 @@ enum reg_fields {
 };
 
 static struct reg_field eusb2_repeater_tune_reg_fields[F_NUM_FIELDS] = {
+	[F_TUNE_EUSB_HS_COMP_CUR] = REG_FIELD(EUSB2_TUNE_EUSB_HS_COMP_CUR, 0, 1),
+	[F_TUNE_EUSB_EQU] = REG_FIELD(EUSB2_TUNE_EUSB_EQU, 0, 1),
+	[F_TUNE_EUSB_SLEW] = REG_FIELD(EUSB2_TUNE_EUSB_SLEW, 0, 1),
+	[F_TUNE_USB2_HS_COMP_CUR] = REG_FIELD(EUSB2_TUNE_USB2_HS_COMP_CUR, 0, 1),
 	[F_TUNE_USB2_PREEM] = REG_FIELD(EUSB2_TUNE_USB2_PREEM, 0, 2),
+	[F_TUNE_USB2_EQU] = REG_FIELD(EUSB2_TUNE_USB2_EQU, 0, 1),
+	[F_TUNE_USB2_SLEW] = REG_FIELD(EUSB2_TUNE_USB2_SLEW, 0, 1),
 	[F_TUNE_SQUELCH_U] = REG_FIELD(EUSB2_TUNE_SQUELCH_U, 0, 2),
+	[F_TUNE_HSDISC] = REG_FIELD(EUSB2_TUNE_HSDISC, 0, 2),
+	[F_TUNE_RES_FSDIF] = REG_FIELD(EUSB2_TUNE_RES_FSDIF, 0, 2),
 	[F_TUNE_IUSB2] = REG_FIELD(EUSB2_TUNE_IUSB2, 0, 3),
+	[F_TUNE_USB2_CROSSOVER] = REG_FIELD(EUSB2_TUNE_USB2_CROSSOVER, 0, 2),
 
 	[F_FORCE_VAL_5] = REG_FIELD(EUSB2_FORCE_VAL_5, 0, 7),
 	[F_FORCE_EN_5] = REG_FIELD(EUSB2_FORCE_EN_5, 0, 7),
@@ -62,13 +89,8 @@ static struct reg_field eusb2_repeater_tune_reg_fields[F_NUM_FIELDS] = {
 	[F_RPTR_STATUS] = REG_FIELD(EUSB2_RPTR_STATUS, 0, 7),
 };
 
-struct eusb2_repeater_init_tbl {
-	unsigned int reg;
-	unsigned int val;
-};
-
 struct eusb2_repeater_cfg {
-	const struct eusb2_repeater_init_tbl *init_tbl;
+	const u32 *init_tbl;
 	int init_tbl_num;
 	const char * const *vreg_list;
 	int num_vregs;
@@ -87,10 +109,10 @@ static const char * const pm8550b_vreg_l[] = {
 	"vdd18", "vdd3",
 };
 
-static const struct eusb2_repeater_init_tbl pm8550b_init_tbl[] = {
-	QCOM_EUSB2_REPEATER_INIT_CFG(F_TUNE_IUSB2, 0x8),
-	QCOM_EUSB2_REPEATER_INIT_CFG(F_TUNE_SQUELCH_U, 0x3),
-	QCOM_EUSB2_REPEATER_INIT_CFG(F_TUNE_USB2_PREEM, 0x5),
+static const u32 pm8550b_init_tbl[F_NUM_TUNE_FIELDS] = {
+	[F_TUNE_IUSB2] = 0x8,
+	[F_TUNE_SQUELCH_U] = 0x3,
+	[F_TUNE_USB2_PREEM] = 0x5,
 };
 
 static const struct eusb2_repeater_cfg pm8550b_eusb2_cfg = {
@@ -118,8 +140,9 @@ static int eusb2_repeater_init_vregs(struct eusb2_repeater *rptr)
 
 static int eusb2_repeater_init(struct phy *phy)
 {
+	struct reg_field *regfields = eusb2_repeater_tune_reg_fields;
 	struct eusb2_repeater *rptr = phy_get_drvdata(phy);
-	const struct eusb2_repeater_init_tbl *init_tbl = rptr->cfg->init_tbl;
+	const u32 *init_tbl = rptr->cfg->init_tbl;
 	u32 val;
 	int ret;
 	int i;
@@ -130,9 +153,16 @@ static int eusb2_repeater_init(struct phy *phy)
 
 	regmap_field_update_bits(rptr->regs[F_EN_CTL1], EUSB2_RPTR_EN, EUSB2_RPTR_EN);
 
-	for (i = 0; i < rptr->cfg->init_tbl_num; i++)
-		regmap_field_update_bits(rptr->regs[init_tbl[i].reg],
-					 init_tbl[i].val, init_tbl[i].val);
+	for (i = 0; i < F_NUM_TUNE_FIELDS; i++) {
+		if (init_tbl[i]) {
+			regmap_field_update_bits(rptr->regs[i], init_tbl[i], init_tbl[i]);
+		} else {
+			/* Write 0 if there's no value set */
+			u32 mask = GENMASK(regfields[i].msb, regfields[i].lsb);
+
+			regmap_field_update_bits(rptr->regs[i], mask, 0);
+		}
+	}
 
 	ret = regmap_field_read_poll_timeout(rptr->regs[F_RPTR_STATUS],
 					     val, val & RPTR_OK, 10, 5);

-- 
2.42.0