[PATCH 3/3] phy: stm32: add phy tuning support
From: Amelie Delaunay
Date: Tue Sep 14 2021 - 10:53:35 EST
It can be necessary to adjust the phys settings to compensate parasitics.
This patch adds support of the new optional property st,phy-tuning to
configure the tune interface of the phys of stm32-usbphyc.
Properties of st,phy-tuning phandle are also 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 <amelie.delaunay@xxxxxxxxxxx>
---
drivers/phy/st/phy-stm32-usbphyc.c | 195 +++++++++++++++++++++++++++++
1 file changed, 195 insertions(+)
diff --git a/drivers/phy/st/phy-stm32-usbphyc.c b/drivers/phy/st/phy-stm32-usbphyc.c
index 083593aea53a..fb7ad7b8e815 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_1_MA = 1,
+ BOOST_2_MA,
+ BOOST_MAX,
+};
+
+enum dc_level_vals {
+ DC_MINUS_5_TO_7_MV,
+ DC_PLUS_5_TO_7_MV,
+ DC_PLUS_10_TO_14_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 +454,111 @@ 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];
+ struct device_node *tune_np;
+ u32 reg = STM32_USBPHYC_TUNE(index);
+ u32 otpcomp, val;
+ int ret;
+
+ /* st,phy-tuning is optional so skip phy tuning if not found */
+ tune_np = of_parse_phandle(np, "st,phy-tuning", 0);
+ if (!tune_np)
+ return;
+
+ /* Backup OTP compensation code */
+ otpcomp = FIELD_GET(OTPCOMP, readl_relaxed(usbphyc->base + reg));
+
+ ret = of_property_read_u32(tune_np, "st,current-boost", &val);
+ if (ret != -EINVAL) {
+ if (!ret && val < BOOST_MAX) {
+ val = (val == BOOST_2_MA) ? 1 : 0;
+ usbphyc_phy->tune |= INCURREN | FIELD_PREP(INCURRINT, val);
+ } else {
+ dev_warn(usbphyc->dev, "phy%d: invalid st,current-boost value\n", index);
+ }
+ }
+
+ if (!of_property_read_bool(tune_np, "st,no-lsfs-fb-cap"))
+ usbphyc_phy->tune |= LFSCAPEN;
+
+ if (of_property_read_bool(tune_np, "st,hs-slew-ctrl"))
+ usbphyc_phy->tune |= HSDRVSLEW;
+
+ ret = of_property_read_u32(tune_np, "st,hs-dc-level", &val);
+ if (ret != -EINVAL) {
+ if (!ret && val < DC_MAX) {
+ if (val == DC_MINUS_5_TO_7_MV) {
+ usbphyc_phy->tune |= HSDRVDCCUR;
+ } else {
+ 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,hs-dc-level value\n", index);
+ }
+ }
+
+ if (of_property_read_bool(tune_np, "st,fs-rftime-tuning"))
+ usbphyc_phy->tune |= FSDRVRFADJ;
+
+ if (of_property_read_bool(tune_np, "st,hs-rftime-reduction"))
+ usbphyc_phy->tune |= HSDRVRFRED;
+
+ ret = of_property_read_u32(tune_np, "st,hs-current-trim", &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,hs-current-trim value\n", index);
+ }
+
+ ret = of_property_read_u32(tune_np, "st,hs-impedance-trim", &val);
+ if (ret != -EINVAL) {
+ if (!ret && val < IMP_MAX)
+ usbphyc_phy->tune |= FIELD_PREP(HSDRVCHKZTRM, val);
+ else
+ dev_warn(usbphyc->dev, "phy%d: invalid hs-impedance-trim value\n", index);
+ }
+
+ ret = of_property_read_u32(tune_np, "st,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,squelch-level value\n", index);
+ }
+
+ if (of_property_read_bool(tune_np, "st,hs-rx-gain-eq"))
+ usbphyc_phy->tune |= HDRXGNEQEN;
+
+ ret = of_property_read_u32(tune_np, "st,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,hs-rx-offset value\n", index);
+ }
+
+ if (of_property_read_bool(tune_np, "st,no-hs-ftime-ctrl"))
+ usbphyc_phy->tune |= HSFALLPREEM;
+
+ if (!of_property_read_bool(tune_np, "st,no-lsfs-sc"))
+ usbphyc_phy->tune |= SHTCCTCTLPROT;
+
+ if (of_property_read_bool(tune_np, "st,hs-tx-staggering"))
+ usbphyc_phy->tune |= STAGSEL;
+
+ of_node_put(tune_np);
+
+ /* Restore OTP compensation code */
+ usbphyc_phy->tune |= FIELD_PREP(OTPCOMP, otpcomp);
+
+ writel_relaxed(usbphyc_phy->tune, usbphyc->base + reg);
+}
+
static void stm32_usbphyc_switch_setup(struct stm32_usbphyc *usbphyc,
u32 utmi_switch)
{
@@ -550,6 +734,9 @@ 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 +788,18 @@ 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];
+ if (usbphyc_phy->tune)
+ writel_relaxed(usbphyc_phy->tune, usbphyc->base + STM32_USBPHYC_TUNE(port));
+ }
+
return 0;
}
--
2.25.1