[PATCH 0/4] EUSB2 repeater init sequence override

[PATCH 0/4] EUSB2 repeater init sequence override

[Konrad Dybcio]

The EUSB2 repeater goes through a tuning sequence as part of its
initialization. This series ensures the tuning is "clean" and can be
overriden for devices that need it.

Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
---
Konrad Dybcio (4):
      dt-bindings: phy: qcom,snps-eusb2-repeater: Add magic tuning overrides
      phy: qualcomm: phy-qcom-eusb2-repeater: Use regmap_fields
      phy: qualcomm: phy-qcom-eusb2-repeater: Zero out untouched tuning regs
      phy: qualcomm: phy-qcom-eusb2-repeater: Add tuning overrides

 .../bindings/phy/qcom,snps-eusb2-repeater.yaml     |  21 ++++
 drivers/phy/qualcomm/phy-qcom-eusb2-repeater.c     | 135 +++++++++++++++------
 2 files changed, 121 insertions(+), 35 deletions(-)
---
base-commit: ae782d4e2bf53b0b642ae860794f7a39470f995a
change-id: 20230830-topic-eusb2_override-aa66df9ca641

Best regards,
-- 
Konrad Dybcio <konrad.dybcio@linaro.org>

[PATCH 1/4] dt-bindings: phy: qcom,snps-eusb2-repeater: Add magic tuning overrides

[Konrad Dybcio]

The EUSB2 repeater requires some alterations to its init sequence,
depending on board design.

Add support for making the necessary changes to that sequence to make USB
functional on SM8550-based Xperia 1 V.

They all have lackluster description due to lack of information.

Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
---
 .../bindings/phy/qcom,snps-eusb2-repeater.yaml      | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/Documentation/devicetree/bindings/phy/qcom,snps-eusb2-repeater.yaml b/Documentation/devicetree/bindings/phy/qcom,snps-eusb2-repeater.yaml
index 029569d5fcf3..83fd6f936bf9 100644
--- a/Documentation/devicetree/bindings/phy/qcom,snps-eusb2-repeater.yaml
+++ b/Documentation/devicetree/bindings/phy/qcom,snps-eusb2-repeater.yaml
@@ -32,6 +32,27 @@ properties:
 
   vdd3-supply: true
 
+  qcom,tune-hsdisc-value:
+    $ref: /schemas/types.yaml#/definitions/uint8
+    description: High-Speed disconnect threshold
+    minimum: 0
+    maximum: 7
+    default: 0
+
+  qcom,tune-iusb2-value:
+    $ref: /schemas/types.yaml#/definitions/uint8
+    description: High-Speed trasmit amplitude
+    minimum: 0
+    maximum: 15
+    default: 8
+
+  qcom,tune-usb2-preem-value:
+    $ref: /schemas/types.yaml#/definitions/uint8
+    description: TX pre-emphasis tuning
+    minimum: 0
+    maximum: 7
+    default: 5
+
 required:
   - compatible
   - reg

-- 
2.42.0

Re: [PATCH 1/4] dt-bindings: phy: qcom,snps-eusb2-repeater: Add magic tuning overrides

[Rob Herring]

On Wed, Aug 30, 2023 at 04:40:15AM +0200, Konrad Dybcio wrote:
> The EUSB2 repeater requires some alterations to its init sequence,
> depending on board design.
> 
> Add support for making the necessary changes to that sequence to make USB
> functional on SM8550-based Xperia 1 V.
> 
> They all have lackluster description due to lack of information.
> 
> Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
> ---
>  .../bindings/phy/qcom,snps-eusb2-repeater.yaml      | 21 +++++++++++++++++++++
>  1 file changed, 21 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/phy/qcom,snps-eusb2-repeater.yaml b/Documentation/devicetree/bindings/phy/qcom,snps-eusb2-repeater.yaml
> index 029569d5fcf3..83fd6f936bf9 100644
> --- a/Documentation/devicetree/bindings/phy/qcom,snps-eusb2-repeater.yaml
> +++ b/Documentation/devicetree/bindings/phy/qcom,snps-eusb2-repeater.yaml
> @@ -32,6 +32,27 @@ properties:
>  
>    vdd3-supply: true
>  
> +  qcom,tune-hsdisc-value:

Is '-value' redundant?

'-thres' or '-threshold' would be more descriptive.

> +    $ref: /schemas/types.yaml#/definitions/uint8
> +    description: High-Speed disconnect threshold
> +    minimum: 0
> +    maximum: 7
> +    default: 0
> +
> +  qcom,tune-iusb2-value:

-amplitude?

> +    $ref: /schemas/types.yaml#/definitions/uint8
> +    description: High-Speed trasmit amplitude
> +    minimum: 0
> +    maximum: 15
> +    default: 8
> +
> +  qcom,tune-usb2-preem-value:

We have 'hs', 'iusb2', and 'usb2'. Can you be consistent?

> +    $ref: /schemas/types.yaml#/definitions/uint8
> +    description: TX pre-emphasis tuning
> +    minimum: 0
> +    maximum: 7
> +    default: 5
> +
>  required:
>    - compatible
>    - reg
> 
> -- 
> 2.42.0
> 

Re: [PATCH 1/4] dt-bindings: phy: qcom,snps-eusb2-repeater: Add magic tuning overrides

[Konrad Dybcio]

On 5.09.2023 18:38, Rob Herring wrote:
> On Wed, Aug 30, 2023 at 04:40:15AM +0200, Konrad Dybcio wrote:
>> The EUSB2 repeater requires some alterations to its init sequence,
>> depending on board design.
>>
>> Add support for making the necessary changes to that sequence to make USB
>> functional on SM8550-based Xperia 1 V.
>>
>> They all have lackluster description due to lack of information.
>>
>> Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
>> ---
>>  .../bindings/phy/qcom,snps-eusb2-repeater.yaml      | 21 +++++++++++++++++++++
>>  1 file changed, 21 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/phy/qcom,snps-eusb2-repeater.yaml b/Documentation/devicetree/bindings/phy/qcom,snps-eusb2-repeater.yaml
>> index 029569d5fcf3..83fd6f936bf9 100644
>> --- a/Documentation/devicetree/bindings/phy/qcom,snps-eusb2-repeater.yaml
>> +++ b/Documentation/devicetree/bindings/phy/qcom,snps-eusb2-repeater.yaml
>> @@ -32,6 +32,27 @@ properties:
>>  
>>    vdd3-supply: true
>>  
>> +  qcom,tune-hsdisc-value:
> 
> Is '-value' redundant?
> 
> '-thres' or '-threshold' would be more descriptive.
All these names are essentially qcom,register-name-value

But I do see your point, it probably makes sense to make it
more human-readable.

> 
>> +    $ref: /schemas/types.yaml#/definitions/uint8
>> +    description: High-Speed disconnect threshold
>> +    minimum: 0
>> +    maximum: 7
>> +    default: 0
>> +
>> +  qcom,tune-iusb2-value:
> 
> -amplitude?
ack

> 
>> +    $ref: /schemas/types.yaml#/definitions/uint8
>> +    description: High-Speed trasmit amplitude
transmit*

>> +    minimum: 0
>> +    maximum: 15
>> +    default: 8
>> +
>> +  qcom,tune-usb2-preem-value:
> 
> We have 'hs', 'iusb2', and 'usb2'. Can you be consistent?
Again, this is taken from register names. I can use 'usb2'
everywhere if you wish.

Konrad

[PATCH 2/4] phy: qualcomm: phy-qcom-eusb2-repeater: Use regmap_fields

[Konrad Dybcio]

Switch to regmap_fields, so that the values written into registers are
sanitized by their explicit sizes and the different registers are
structured in an iterable object to make external changes to the init
sequence simpler.

Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
---
 drivers/phy/qualcomm/phy-qcom-eusb2-repeater.c | 91 +++++++++++++++++---------
 1 file changed, 61 insertions(+), 30 deletions(-)

diff --git a/drivers/phy/qualcomm/phy-qcom-eusb2-repeater.c b/drivers/phy/qualcomm/phy-qcom-eusb2-repeater.c
index 52c275fbb2a1..7561da01e633 100644
--- a/drivers/phy/qualcomm/phy-qcom-eusb2-repeater.c
+++ b/drivers/phy/qualcomm/phy-qcom-eusb2-repeater.c
@@ -28,14 +28,42 @@
 #define EUSB2_TUNE_SQUELCH_U		0x54
 #define EUSB2_TUNE_USB2_PREEM		0x57
 
-#define QCOM_EUSB2_REPEATER_INIT_CFG(o, v)	\
+#define QCOM_EUSB2_REPEATER_INIT_CFG(r, v)	\
 	{					\
-		.offset = o,			\
+		.reg = r,			\
 		.val = v,			\
 	}
 
+enum reg_fields {
+	F_TUNE_USB2_PREEM,
+	F_TUNE_SQUELCH_U,
+	F_TUNE_IUSB2,
+	F_NUM_TUNE_FIELDS,
+
+	F_FORCE_VAL_5 = F_NUM_TUNE_FIELDS,
+	F_FORCE_EN_5,
+
+	F_EN_CTL1,
+
+	F_RPTR_STATUS,
+	F_NUM_FIELDS,
+};
+
+static struct reg_field eusb2_repeater_tune_reg_fields[F_NUM_FIELDS] = {
+	[F_TUNE_USB2_PREEM] = REG_FIELD(EUSB2_TUNE_USB2_PREEM, 0, 2),
+	[F_TUNE_SQUELCH_U] = REG_FIELD(EUSB2_TUNE_SQUELCH_U, 0, 2),
+	[F_TUNE_IUSB2] = REG_FIELD(EUSB2_TUNE_IUSB2, 0, 3),
+
+	[F_FORCE_VAL_5] = REG_FIELD(EUSB2_FORCE_VAL_5, 0, 7),
+	[F_FORCE_EN_5] = REG_FIELD(EUSB2_FORCE_EN_5, 0, 7),
+
+	[F_EN_CTL1] = REG_FIELD(EUSB2_EN_CTL1, 0, 7),
+
+	[F_RPTR_STATUS] = REG_FIELD(EUSB2_RPTR_STATUS, 0, 7),
+};
+
 struct eusb2_repeater_init_tbl {
-	unsigned int offset;
+	unsigned int reg;
 	unsigned int val;
 };
 
@@ -48,11 +76,10 @@ struct eusb2_repeater_cfg {
 
 struct eusb2_repeater {
 	struct device *dev;
-	struct regmap *regmap;
+	struct regmap_field *regs[F_NUM_FIELDS];
 	struct phy *phy;
 	struct regulator_bulk_data *vregs;
 	const struct eusb2_repeater_cfg *cfg;
-	u16 base;
 	enum phy_mode mode;
 };
 
@@ -61,9 +88,9 @@ static const char * const pm8550b_vreg_l[] = {
 };
 
 static const struct eusb2_repeater_init_tbl pm8550b_init_tbl[] = {
-	QCOM_EUSB2_REPEATER_INIT_CFG(EUSB2_TUNE_IUSB2, 0x8),
-	QCOM_EUSB2_REPEATER_INIT_CFG(EUSB2_TUNE_SQUELCH_U, 0x3),
-	QCOM_EUSB2_REPEATER_INIT_CFG(EUSB2_TUNE_USB2_PREEM, 0x5),
+	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 struct eusb2_repeater_cfg pm8550b_eusb2_cfg = {
@@ -93,7 +120,6 @@ static int eusb2_repeater_init(struct phy *phy)
 {
 	struct eusb2_repeater *rptr = phy_get_drvdata(phy);
 	const struct eusb2_repeater_init_tbl *init_tbl = rptr->cfg->init_tbl;
-	int num = rptr->cfg->init_tbl_num;
 	u32 val;
 	int ret;
 	int i;
@@ -102,17 +128,14 @@ static int eusb2_repeater_init(struct phy *phy)
 	if (ret)
 		return ret;
 
-	regmap_update_bits(rptr->regmap, rptr->base + EUSB2_EN_CTL1,
-			   EUSB2_RPTR_EN, EUSB2_RPTR_EN);
+	regmap_field_update_bits(rptr->regs[F_EN_CTL1], EUSB2_RPTR_EN, EUSB2_RPTR_EN);
 
-	for (i = 0; i < num; i++)
-		regmap_update_bits(rptr->regmap,
-				   rptr->base + init_tbl[i].offset,
-				   init_tbl[i].val, init_tbl[i].val);
+	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);
 
-	ret = regmap_read_poll_timeout(rptr->regmap,
-				       rptr->base + EUSB2_RPTR_STATUS, val,
-				       val & RPTR_OK, 10, 5);
+	ret = regmap_field_read_poll_timeout(rptr->regs[F_RPTR_STATUS],
+					     val, val & RPTR_OK, 10, 5);
 	if (ret)
 		dev_err(rptr->dev, "initialization timed-out\n");
 
@@ -131,10 +154,10 @@ static int eusb2_repeater_set_mode(struct phy *phy,
 		 * per eUSB 1.2 Spec. Below implement software workaround until
 		 * PHY and controller is fixing seen observation.
 		 */
-		regmap_update_bits(rptr->regmap, rptr->base + EUSB2_FORCE_EN_5,
-				   F_CLK_19P2M_EN, F_CLK_19P2M_EN);
-		regmap_update_bits(rptr->regmap, rptr->base + EUSB2_FORCE_VAL_5,
-				   V_CLK_19P2M_EN, V_CLK_19P2M_EN);
+		regmap_field_update_bits(rptr->regs[F_FORCE_EN_5],
+					 F_CLK_19P2M_EN, F_CLK_19P2M_EN);
+		regmap_field_update_bits(rptr->regs[F_FORCE_VAL_5],
+					 V_CLK_19P2M_EN, V_CLK_19P2M_EN);
 		break;
 	case PHY_MODE_USB_DEVICE:
 		/*
@@ -143,10 +166,10 @@ static int eusb2_repeater_set_mode(struct phy *phy,
 		 * repeater doesn't clear previous value due to shared
 		 * regulators (say host <-> device mode switch).
 		 */
-		regmap_update_bits(rptr->regmap, rptr->base + EUSB2_FORCE_EN_5,
-				   F_CLK_19P2M_EN, 0);
-		regmap_update_bits(rptr->regmap, rptr->base + EUSB2_FORCE_VAL_5,
-				   V_CLK_19P2M_EN, 0);
+		regmap_field_update_bits(rptr->regs[F_FORCE_EN_5],
+					 F_CLK_19P2M_EN, 0);
+		regmap_field_update_bits(rptr->regs[F_FORCE_VAL_5],
+					 V_CLK_19P2M_EN, 0);
 		break;
 	default:
 		return -EINVAL;
@@ -175,8 +198,9 @@ static int eusb2_repeater_probe(struct platform_device *pdev)
 	struct device *dev = &pdev->dev;
 	struct phy_provider *phy_provider;
 	struct device_node *np = dev->of_node;
+	struct regmap *regmap;
+	int i, ret;
 	u32 res;
-	int ret;
 
 	rptr = devm_kzalloc(dev, sizeof(*rptr), GFP_KERNEL);
 	if (!rptr)
@@ -189,15 +213,22 @@ static int eusb2_repeater_probe(struct platform_device *pdev)
 	if (!rptr->cfg)
 		return -EINVAL;
 
-	rptr->regmap = dev_get_regmap(dev->parent, NULL);
-	if (!rptr->regmap)
+	regmap = dev_get_regmap(dev->parent, NULL);
+	if (!regmap)
 		return -ENODEV;
 
 	ret = of_property_read_u32(np, "reg", &res);
 	if (ret < 0)
 		return ret;
 
-	rptr->base = res;
+	for (i = 0; i < F_NUM_FIELDS; i++)
+		eusb2_repeater_tune_reg_fields[i].reg += res;
+
+	ret = devm_regmap_field_bulk_alloc(dev, regmap, rptr->regs,
+					   eusb2_repeater_tune_reg_fields,
+					   F_NUM_FIELDS);
+	if (ret)
+		return ret;
 
 	ret = eusb2_repeater_init_vregs(rptr);
 	if (ret < 0) {

-- 
2.42.0

[PATCH 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@linaro.org>
---
 drivers/phy/qualcomm/phy-qcom-eusb2-repeater.c | 49 ++++++++++++++++++--------
 1 file changed, 35 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..645f0e95703a 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 = {
@@ -119,7 +141,7 @@ static int eusb2_repeater_init_vregs(struct eusb2_repeater *rptr)
 static int eusb2_repeater_init(struct phy *phy)
 {
 	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 +152,8 @@ 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++)
+		regmap_field_update_bits(rptr->regs[i], init_tbl[i], init_tbl[i]);
 
 	ret = regmap_field_read_poll_timeout(rptr->regs[F_RPTR_STATUS],
 					     val, val & RPTR_OK, 10, 5);

-- 
2.42.0

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

[Konrad Dybcio]

On 30.08.2023 04:40, Konrad Dybcio wrote:
> The vendor kernel zeroes out all tuning data outside the init sequence
> as part of initialization. Follow suit to avoid UB.
This patch doesn't do what it says. It passes 0x0 as val and mask
to regmap_update_bits resulting in a NOP, still..

Konrad

[PATCH 4/4] phy: qualcomm: phy-qcom-eusb2-repeater: Add tuning overrides

[Konrad Dybcio]

There are devices in the wild, like the Sony Xperia 1 V that *require*
different tuning than the base design for USB to work.

Add support for overriding the necessary tuning values.

Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
---
 drivers/phy/qualcomm/phy-qcom-eusb2-repeater.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/drivers/phy/qualcomm/phy-qcom-eusb2-repeater.c b/drivers/phy/qualcomm/phy-qcom-eusb2-repeater.c
index 645f0e95703a..53e10feb16a1 100644
--- a/drivers/phy/qualcomm/phy-qcom-eusb2-repeater.c
+++ b/drivers/phy/qualcomm/phy-qcom-eusb2-repeater.c
@@ -141,7 +141,9 @@ static int eusb2_repeater_init_vregs(struct eusb2_repeater *rptr)
 static int eusb2_repeater_init(struct phy *phy)
 {
 	struct eusb2_repeater *rptr = phy_get_drvdata(phy);
-	const u32 *init_tbl = rptr->cfg->init_tbl;
+	struct device_node *np = rptr->dev->of_node;
+	u32 init_tbl[F_NUM_TUNE_FIELDS] = { 0 };
+	u8 override;
 	u32 val;
 	int ret;
 	int i;
@@ -152,6 +154,17 @@ static int eusb2_repeater_init(struct phy *phy)
 
 	regmap_field_update_bits(rptr->regs[F_EN_CTL1], EUSB2_RPTR_EN, EUSB2_RPTR_EN);
 
+	memcpy(init_tbl, rptr->cfg->init_tbl, sizeof(init_tbl));
+
+	if (!of_property_read_u8(np, "qcom,tune-iusb2-value", &override))
+		init_tbl[F_TUNE_IUSB2] = override;
+
+	if (!of_property_read_u8(np, "qcom,tune-hsdisc-value", &override))
+		init_tbl[F_TUNE_HSDISC] = override;
+
+	if (!of_property_read_u8(np, "qcom,tune-usb2-preem-value", &override))
+		init_tbl[F_TUNE_USB2_PREEM] = override;
+
 	for (i = 0; i < F_NUM_TUNE_FIELDS; i++)
 		regmap_field_update_bits(rptr->regs[i], init_tbl[i], init_tbl[i]);
 

-- 
2.42.0