2021-10-17 00:44:24

by Amelie Delaunay

[permalink] [raw]
Subject: [PATCH v3 0/3] phy: stm32: add phy tuning support

This series brings phy tuning to stm32-usbphyc with new optional
device tree properties.
A prior patch add resume routine, which is used to restore UTMI
switch and phy tuning configuration, as they can be reset if
deep low power state is achieved.

Amelie Delaunay (3):
phy: stm32: restore utmi switch on resume
dt-bindings: phy: phy-stm32-usbphyc: add optional phy tuning
properties
phy: stm32: add phy tuning support

---
Changes in v3:
- Use -microamp for current boost
- '|' added after 'description:' on each properties needing this
Changes in v2:
- st,phy-tuning + usb_phy_tuning node removed
- properties are now in phy child nodes

.../bindings/phy/phy-stm32-usbphyc.yaml | 129 +++++++++++
drivers/phy/st/phy-stm32-usbphyc.c | 203 ++++++++++++++++++
2 files changed, 332 insertions(+)

--
2.25.1


2021-10-17 00:44:36

by Amelie Delaunay

[permalink] [raw]
Subject: [PATCH v3 1/3] phy: stm32: restore utmi switch on resume

UTMI switch value can be lost during suspend/resume, depending on the power
state reached.
This patch adds resume function to usbphyc, to reconfigure utmi switch
after suspend.

Signed-off-by: Amelie Delaunay <[email protected]>
---
drivers/phy/st/phy-stm32-usbphyc.c | 13 +++++++++++++
1 file changed, 13 insertions(+)

diff --git a/drivers/phy/st/phy-stm32-usbphyc.c b/drivers/phy/st/phy-stm32-usbphyc.c
index 937a14fa7448..083593aea53a 100644
--- a/drivers/phy/st/phy-stm32-usbphyc.c
+++ b/drivers/phy/st/phy-stm32-usbphyc.c
@@ -598,6 +598,18 @@ static int stm32_usbphyc_remove(struct platform_device *pdev)
return 0;
}

+static int __maybe_unused stm32_usbphyc_resume(struct device *dev)
+{
+ struct stm32_usbphyc *usbphyc = dev_get_drvdata(dev);
+
+ if (usbphyc->switch_setup >= 0)
+ stm32_usbphyc_switch_setup(usbphyc, usbphyc->switch_setup);
+
+ return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(stm32_usbphyc_pm_ops, NULL, stm32_usbphyc_resume);
+
static const struct of_device_id stm32_usbphyc_of_match[] = {
{ .compatible = "st,stm32mp1-usbphyc", },
{ },
@@ -610,6 +622,7 @@ static struct platform_driver stm32_usbphyc_driver = {
.driver = {
.of_match_table = stm32_usbphyc_of_match,
.name = "stm32-usbphyc",
+ .pm = &stm32_usbphyc_pm_ops,
}
};
module_platform_driver(stm32_usbphyc_driver);
--
2.25.1

2021-10-17 01:20:57

by Amelie Delaunay

[permalink] [raw]
Subject: [PATCH v3 2/3] dt-bindings: phy: phy-stm32-usbphyc: add optional phy tuning properties

This patch adds the description of new optional phy tuning properties
for usbphyc phy sub nodes.

Signed-off-by: Amelie Delaunay <[email protected]>
---
Changes in v3:
- Use -microamp instead of undocumented -milliamp
- Add '|' after 'description:' on each property needing this
Changes in v2:
- st,phy-tuning property removed
- tuning properties are now put directly in each child node
- tuning properties are no more free form text and their name reworked
---
.../bindings/phy/phy-stm32-usbphyc.yaml | 129 ++++++++++++++++++
1 file changed, 129 insertions(+)

diff --git a/Documentation/devicetree/bindings/phy/phy-stm32-usbphyc.yaml b/Documentation/devicetree/bindings/phy/phy-stm32-usbphyc.yaml
index 3329f1d33a4f..225128364a63 100644
--- a/Documentation/devicetree/bindings/phy/phy-stm32-usbphyc.yaml
+++ b/Documentation/devicetree/bindings/phy/phy-stm32-usbphyc.yaml
@@ -81,6 +81,119 @@ patternProperties:
properties:
vbus-supply: true

+ # It can be necessary to adjust the PHY settings to compensate parasitics, which can be due
+ # to USB connector/receptacle, routing, ESD protection component,... Here is the list of
+ # all optional parameters to tune the interface of the PHY (HS for High-Speed, FS for Full-
+ # Speed, LS for Low-Speed)
+
+ st,current-boost-microamp:
+ description: Current boosting in uA
+ enum: [ 1000, 2000 ]
+
+ st,no-lsfs-fb-cap:
+ description: Disables the LS/FS feedback capacitor
+ type: boolean
+
+ st,decrease-hs-slew-rate:
+ description: Decreases the HS driver slew rate by 10%
+ type: boolean
+
+ st,tune-hs-dc-level:
+ description: |
+ Tunes the HS driver DC level
+ - <0> normal level
+ - <1> increases the level by 5 to 7 mV
+ - <2> increases the level by 10 to 14 mV
+ - <3> decreases the level by 5 to 7 mV
+ $ref: /schemas/types.yaml#/definitions/uint32
+ minimum: 0
+ maximum: 3
+ default: 0
+
+ st,enable-fs-rftime-tuning:
+ description: Enables the FS rise/fall tuning option
+ type: boolean
+
+ st,enable-hs-rftime-reduction:
+ description: Enables the HS rise/fall reduction feature
+ type: boolean
+
+ st,trim-hs-current:
+ description: |
+ Controls HS driver current trimming for choke compensation
+ - <0> = 18.87 mA target current / nominal + 0%
+ - <1> = 19.165 mA target current / nominal + 1.56%
+ - <2> = 19.46 mA target current / nominal + 3.12%
+ - <3> = 19.755 mA target current / nominal + 4.68%
+ - <4> = 20.05 mA target current / nominal + 6.24%
+ - <5> = 20.345 mA target current / nominal + 7.8%
+ - <6> = 20.64 mA target current / nominal + 9.36%
+ - <7> = 20.935 mA target current / nominal + 10.92%
+ - <8> = 21.23 mA target current / nominal + 12.48%
+ - <9> = 21.525 mA target current / nominal + 14.04%
+ - <10> = 21.82 mA target current / nominal + 15.6%
+ - <11> = 22.115 mA target current / nominal + 17.16%
+ - <12> = 22.458 mA target current / nominal + 19.01%
+ - <13> = 22.755 mA target current / nominal + 20.58%
+ - <14> = 23.052 mA target current / nominal + 22.16%
+ - <15> = 23.348 mA target current / nominal + 23.73%
+ $ref: /schemas/types.yaml#/definitions/uint32
+ minimum: 0
+ maximum: 15
+ default: 0
+
+ st,trim-hs-impedance:
+ description: |
+ Controls HS driver impedance tuning for choke compensation
+ - <0> = no impedance offset
+ - <1> = reduce the impedance by 2 ohms
+ - <2> = reduce the impedance by 4 ohms
+ - <3> = reduce the impedance by 6 ohms
+ $ref: /schemas/types.yaml#/definitions/uint32
+ minimum: 0
+ maximum: 3
+ default: 0
+
+ st,tune-squelch-level:
+ description: |
+ Tunes the squelch DC threshold value
+ - <0> = no shift in threshold
+ - <1> = threshold shift by +7 mV
+ - <2> = threshold shift by -5 mV
+ - <3> = threshold shift by +14 mV
+ $ref: /schemas/types.yaml#/definitions/uint32
+ minimum: 0
+ maximum: 3
+ default: 0
+
+ st,enable-hs-rx-gain-eq:
+ description: Enables the HS Rx gain equalizer
+ type: boolean
+
+ st,tune-hs-rx-offset:
+ description: |
+ Adjusts the HS Rx offset
+ - <0> = no offset
+ - <1> = offset of +5 mV
+ - <2> = offset of +10 mV
+ - <3> = offset of -5 mV
+ $ref: /schemas/types.yaml#/definitions/uint32
+ minimum: 0
+ maximum: 3
+ default: 0
+
+ st,no-hs-ftime-ctrl:
+ description: Disables the HS fall time control of single ended signals during pre-emphasis
+ type: boolean
+
+ st,no-lsfs-sc:
+ description: Disables the short circuit protection in LS/FS driver
+ type: boolean
+
+ st,enable-hs-tx-staggering:
+ description: Enables the basic staggering in HS Tx mode
+ type: boolean
+
allOf:
- if:
properties:
@@ -137,6 +250,14 @@ examples:
reg = <0>;
phy-supply = <&vdd_usb>;
#phy-cells = <0>;
+ st,tune-hs-dc-level = <2>;
+ st,enable-fs-rftime-tuning;
+ st,enable-hs-rftime-reduction;
+ st,trim-hs-current = <15>;
+ st,trim-hs-impedance = <1>;
+ st,tune-squelch-level = <3>;
+ st,tune-hs-rx-offset = <2>;
+ st,no-lsfs-sc;
connector {
compatible = "usb-a-connector";
vbus-supply = <&vbus_sw>;
@@ -147,6 +268,14 @@ examples:
reg = <1>;
phy-supply = <&vdd_usb>;
#phy-cells = <1>;
+ st,tune-hs-dc-level = <2>;
+ st,enable-fs-rftime-tuning;
+ st,enable-hs-rftime-reduction;
+ st,trim-hs-current = <15>;
+ st,trim-hs-impedance = <1>;
+ st,tune-squelch-level = <3>;
+ st,tune-hs-rx-offset = <2>;
+ st,no-lsfs-sc;
};
};
...
--
2.25.1

2021-10-17 01:40:27

by Amelie Delaunay

[permalink] [raw]
Subject: [PATCH v3 3/3] phy: stm32: add phy tuning support

It can be necessary to adjust the phys settings to compensate parasitics.
This patch adds support of new optional properties to configure the tune
interface of the phys of stm32-usbphyc.
Properties are optional, that's why each property is skipped if not
found (-EINVAL).
Phy tuning is restored on resume because if deep low power state is
achieved, phy tuning configuration is reset.

Signed-off-by: Amelie Delaunay <[email protected]>
---
drivers/phy/st/phy-stm32-usbphyc.c | 190 +++++++++++++++++++++++++++++
1 file changed, 190 insertions(+)

diff --git a/drivers/phy/st/phy-stm32-usbphyc.c b/drivers/phy/st/phy-stm32-usbphyc.c
index 083593aea53a..7df6a63ad37b 100644
--- a/drivers/phy/st/phy-stm32-usbphyc.c
+++ b/drivers/phy/st/phy-stm32-usbphyc.c
@@ -20,6 +20,7 @@
#define STM32_USBPHYC_PLL 0x0
#define STM32_USBPHYC_MISC 0x8
#define STM32_USBPHYC_MONITOR(X) (0x108 + ((X) * 0x100))
+#define STM32_USBPHYC_TUNE(X) (0x10C + ((X) * 0x100))
#define STM32_USBPHYC_VERSION 0x3F4

/* STM32_USBPHYC_PLL bit fields */
@@ -41,6 +42,83 @@
#define STM32_USBPHYC_MON_SEL_LOCKP 0x1F
#define STM32_USBPHYC_MON_OUT_LOCKP BIT(3)

+/* STM32_USBPHYC_TUNE bit fields */
+#define INCURREN BIT(0)
+#define INCURRINT BIT(1)
+#define LFSCAPEN BIT(2)
+#define HSDRVSLEW BIT(3)
+#define HSDRVDCCUR BIT(4)
+#define HSDRVDCLEV BIT(5)
+#define HSDRVCURINCR BIT(6)
+#define FSDRVRFADJ BIT(7)
+#define HSDRVRFRED BIT(8)
+#define HSDRVCHKITRM GENMASK(12, 9)
+#define HSDRVCHKZTRM GENMASK(14, 13)
+#define OTPCOMP GENMASK(19, 15)
+#define SQLCHCTL GENMASK(21, 20)
+#define HDRXGNEQEN BIT(22)
+#define HSRXOFF GENMASK(24, 23)
+#define HSFALLPREEM BIT(25)
+#define SHTCCTCTLPROT BIT(26)
+#define STAGSEL BIT(27)
+
+enum boosting_vals {
+ BOOST_1000_UA = 1000,
+ BOOST_2000_UA = 2000,
+};
+
+enum dc_level_vals {
+ DC_NOMINAL,
+ DC_PLUS_5_TO_7_MV,
+ DC_PLUS_10_TO_14_MV,
+ DC_MINUS_5_TO_7_MV,
+ DC_MAX,
+};
+
+enum current_trim {
+ CUR_NOMINAL,
+ CUR_PLUS_1_56_PCT,
+ CUR_PLUS_3_12_PCT,
+ CUR_PLUS_4_68_PCT,
+ CUR_PLUS_6_24_PCT,
+ CUR_PLUS_7_8_PCT,
+ CUR_PLUS_9_36_PCT,
+ CUR_PLUS_10_92_PCT,
+ CUR_PLUS_12_48_PCT,
+ CUR_PLUS_14_04_PCT,
+ CUR_PLUS_15_6_PCT,
+ CUR_PLUS_17_16_PCT,
+ CUR_PLUS_19_01_PCT,
+ CUR_PLUS_20_58_PCT,
+ CUR_PLUS_22_16_PCT,
+ CUR_PLUS_23_73_PCT,
+ CUR_MAX,
+};
+
+enum impedance_trim {
+ IMP_NOMINAL,
+ IMP_MINUS_2_OHMS,
+ IMP_MINUS_4_OMHS,
+ IMP_MINUS_6_OHMS,
+ IMP_MAX,
+};
+
+enum squelch_level {
+ SQLCH_NOMINAL,
+ SQLCH_PLUS_7_MV,
+ SQLCH_MINUS_5_MV,
+ SQLCH_PLUS_14_MV,
+ SQLCH_MAX,
+};
+
+enum rx_offset {
+ NO_RX_OFFSET,
+ RX_OFFSET_PLUS_5_MV,
+ RX_OFFSET_PLUS_10_MV,
+ RX_OFFSET_MINUS_5_MV,
+ RX_OFFSET_MAX,
+};
+
/* STM32_USBPHYC_VERSION bit fields */
#define MINREV GENMASK(3, 0)
#define MAJREV GENMASK(7, 4)
@@ -60,6 +138,7 @@ struct stm32_usbphyc_phy {
struct regulator *vbus;
u32 index;
bool active;
+ u32 tune;
};

struct stm32_usbphyc {
@@ -375,6 +454,107 @@ static int stm32_usbphyc_clk48_register(struct stm32_usbphyc *usbphyc)
return ret;
}

+static void stm32_usbphyc_phy_tuning(struct stm32_usbphyc *usbphyc,
+ struct device_node *np, u32 index)
+{
+ struct stm32_usbphyc_phy *usbphyc_phy = usbphyc->phys[index];
+ u32 reg = STM32_USBPHYC_TUNE(index);
+ u32 otpcomp, val;
+ int ret;
+
+ /* Backup OTP compensation code */
+ otpcomp = FIELD_GET(OTPCOMP, readl_relaxed(usbphyc->base + reg));
+
+ ret = of_property_read_u32(np, "st,current-boost-microamp", &val);
+ if (ret != -EINVAL) {
+ if (!ret && (val == BOOST_1000_UA || val == BOOST_2000_UA)) {
+ val = (val == BOOST_2000_UA) ? 1 : 0;
+ usbphyc_phy->tune |= INCURREN | FIELD_PREP(INCURRINT, val);
+ } else {
+ dev_warn(usbphyc->dev, "phy%d: invalid st,current-boost-microamp\n", index);
+ }
+ }
+
+ if (!of_property_read_bool(np, "st,no-lsfs-fb-cap"))
+ usbphyc_phy->tune |= LFSCAPEN;
+
+ if (of_property_read_bool(np, "st,slow-hs-slew-rate"))
+ usbphyc_phy->tune |= HSDRVSLEW;
+
+ ret = of_property_read_u32(np, "st,tune-hs-dc-level", &val);
+ if (ret != -EINVAL) {
+ if (!ret && val < DC_MAX) {
+ if (val == DC_MINUS_5_TO_7_MV) {/* Decreases HS driver DC level */
+ usbphyc_phy->tune |= HSDRVDCCUR;
+ } else if (val > 0) { /* Increases HS driver DC level */
+ val = (val == DC_PLUS_10_TO_14_MV) ? 1 : 0;
+ usbphyc_phy->tune |= HSDRVCURINCR | FIELD_PREP(HSDRVDCLEV, val);
+ }
+ } else {
+ dev_warn(usbphyc->dev, "phy%d: invalid st,tune-hs-dc-level\n", index);
+ }
+ }
+
+ if (of_property_read_bool(np, "st,enable-fs-rftime-tuning"))
+ usbphyc_phy->tune |= FSDRVRFADJ;
+
+ if (of_property_read_bool(np, "st,enable-hs-rftime-reduction"))
+ usbphyc_phy->tune |= HSDRVRFRED;
+
+ ret = of_property_read_u32(np, "st,trim-hs-current", &val);
+ if (ret != -EINVAL) {
+ if (!ret && val < CUR_MAX)
+ usbphyc_phy->tune |= FIELD_PREP(HSDRVCHKITRM, val);
+ else
+ dev_warn(usbphyc->dev, "phy%d: invalid st,trim-hs-current\n", index);
+ }
+
+ ret = of_property_read_u32(np, "st,trim-hs-impedance", &val);
+ if (ret != -EINVAL) {
+ if (!ret && val < IMP_MAX)
+ usbphyc_phy->tune |= FIELD_PREP(HSDRVCHKZTRM, val);
+ else
+ dev_warn(usbphyc->dev, "phy%d: invalid st,trim-hs-impedance\n", index);
+ }
+
+ ret = of_property_read_u32(np, "st,tune-squelch-level", &val);
+ if (ret != -EINVAL) {
+ if (!ret && val < SQLCH_MAX)
+ usbphyc_phy->tune |= FIELD_PREP(SQLCHCTL, val);
+ else
+ dev_warn(usbphyc->dev, "phy%d: invalid st,tune-squelch\n", index);
+ }
+
+ if (of_property_read_bool(np, "st,enable-hs-rx-gain-eq"))
+ usbphyc_phy->tune |= HDRXGNEQEN;
+
+ ret = of_property_read_u32(np, "st,tune-hs-rx-offset", &val);
+ if (ret != -EINVAL) {
+ if (!ret && val < RX_OFFSET_MAX)
+ usbphyc_phy->tune |= FIELD_PREP(HSRXOFF, val);
+ else
+ dev_warn(usbphyc->dev, "phy%d: invalid st,tune-hs-rx-offset\n", index);
+ }
+
+ if (of_property_read_bool(np, "st,no-hs-ftime-ctrl"))
+ usbphyc_phy->tune |= HSFALLPREEM;
+
+ if (!of_property_read_bool(np, "st,no-lsfs-sc"))
+ usbphyc_phy->tune |= SHTCCTCTLPROT;
+
+ if (of_property_read_bool(np, "st,enable-hs-tx-staggering"))
+ usbphyc_phy->tune |= STAGSEL;
+
+ /* Restore OTP compensation code */
+ usbphyc_phy->tune |= FIELD_PREP(OTPCOMP, otpcomp);
+
+ /*
+ * By default, if no st,xxx tuning property is used, usbphyc_phy->tune is equal to
+ * STM32_USBPHYC_TUNE reset value (LFSCAPEN | SHTCCTCTLPROT | OTPCOMP).
+ */
+ writel_relaxed(usbphyc_phy->tune, usbphyc->base + reg);
+}
+
static void stm32_usbphyc_switch_setup(struct stm32_usbphyc *usbphyc,
u32 utmi_switch)
{
@@ -550,6 +730,9 @@ static int stm32_usbphyc_probe(struct platform_device *pdev)
usbphyc->phys[port]->vbus = NULL;
}

+ /* Configure phy tuning */
+ stm32_usbphyc_phy_tuning(usbphyc, child, index);
+
port++;
}

@@ -601,10 +784,17 @@ static int stm32_usbphyc_remove(struct platform_device *pdev)
static int __maybe_unused stm32_usbphyc_resume(struct device *dev)
{
struct stm32_usbphyc *usbphyc = dev_get_drvdata(dev);
+ struct stm32_usbphyc_phy *usbphyc_phy;
+ int port;

if (usbphyc->switch_setup >= 0)
stm32_usbphyc_switch_setup(usbphyc, usbphyc->switch_setup);

+ for (port = 0; port < usbphyc->nphys; port++) {
+ usbphyc_phy = usbphyc->phys[port];
+ writel_relaxed(usbphyc_phy->tune, usbphyc->base + STM32_USBPHYC_TUNE(port));
+ }
+
return 0;
}

--
2.25.1

2021-10-18 19:32:19

by Rob Herring (Arm)

[permalink] [raw]
Subject: Re: [PATCH v3 2/3] dt-bindings: phy: phy-stm32-usbphyc: add optional phy tuning properties

On Fri, 15 Oct 2021 18:14:26 +0200, Amelie Delaunay wrote:
> This patch adds the description of new optional phy tuning properties
> for usbphyc phy sub nodes.
>
> Signed-off-by: Amelie Delaunay <[email protected]>
> ---
> Changes in v3:
> - Use -microamp instead of undocumented -milliamp
> - Add '|' after 'description:' on each property needing this
> Changes in v2:
> - st,phy-tuning property removed
> - tuning properties are now put directly in each child node
> - tuning properties are no more free form text and their name reworked
> ---
> .../bindings/phy/phy-stm32-usbphyc.yaml | 129 ++++++++++++++++++
> 1 file changed, 129 insertions(+)
>

Reviewed-by: Rob Herring <[email protected]>

2021-10-19 18:08:26

by Vinod Koul

[permalink] [raw]
Subject: Re: [PATCH v3 0/3] phy: stm32: add phy tuning support

On 15-10-21, 18:14, Amelie Delaunay wrote:
> This series brings phy tuning to stm32-usbphyc with new optional
> device tree properties.
> A prior patch add resume routine, which is used to restore UTMI
> switch and phy tuning configuration, as they can be reset if
> deep low power state is achieved.

Applied, thanks

--
~Vinod