phy: stm32-usbphyc: stm32-usbphyc: Add DT phy tuning support

Add support of phy-tuning properties for sm32-usbphyc's phy tuning
aligned with v5.15 kernel bindings.

Signed-off-by: Patrice Chotard <patrice.chotard@foss.st.com>
Reviewed-by: Patrick Delaunay <patrick.delaunay@foss.st.com>

1 files changed, 167 insertions, 0 deletions

diff --git a/drivers/phy/phy-stm32-usbphyc.c b/drivers/phy/phy-stm32-usbphyc.c
index 9c1dcfa..d7f7c37 100644
--- a/drivers/phy/phy-stm32-usbphyc.c
+++ b/drivers/phy/phy-stm32-usbphyc.c
@@ -17,6 +17,8 @@
 #include <usb.h>
 #include <asm/io.h>
 #include <dm/device_compat.h>
+#include <dm/of_access.h>
+#include <linux/bitfield.h>
 #include <linux/bitops.h>
 #include <linux/delay.h>
 #include <power/regulator.h>
@@ -24,6 +26,7 @@
 /* USBPHYC registers */
 #define STM32_USBPHYC_PLL	0x0
 #define STM32_USBPHYC_MISC	0x8
+#define STM32_USBPHYC_TUNE(X)	(0x10C + ((X) * 0x100))
 
 /* STM32_USBPHYC_PLL bit fields */
 #define PLLNDIV			GENMASK(6, 0)
@@ -40,6 +43,26 @@
 /* STM32_USBPHYC_MISC bit fields */
 #define SWITHOST		BIT(0)
 
+/* 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)
+
 #define MAX_PHYS		2
 
 /* max 100 us for PLL lock and 100 us for PHY init */
@@ -49,6 +72,62 @@
 #define PLL_INFF_MIN_RATE	19200000 /* in Hz */
 #define PLL_INFF_MAX_RATE	38400000 /* in Hz */
 
+enum boosting_vals {
+	BOOST_1000_UA = 1000,
+	BOOST_2000_UA = 2000,
+};
+
+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,
+};
+
 struct pll_params {
 	u8 ndiv;
 	u16 frac;
@@ -327,6 +406,90 @@ static int stm32_usbphyc_of_xlate(struct phy *phy,
 	return 0;
 }
 
+static void stm32_usbphyc_tuning(struct udevice *dev, ofnode node, u32 index)
+{
+	struct stm32_usbphyc *usbphyc = dev_get_priv(dev);
+	u32 reg = STM32_USBPHYC_TUNE(index);
+	u32 otpcomp, val, tune = 0;
+	int ret;
+
+	/* Backup OTP compensation code */
+	otpcomp = FIELD_GET(OTPCOMP, readl(usbphyc->base + reg));
+
+	ret = ofnode_read_u32(node, "st,current-boost-microamp", &val);
+	if (!ret && (val == BOOST_1000_UA || val == BOOST_2000_UA)) {
+		val = (val == BOOST_2000_UA) ? 1 : 0;
+		tune |= INCURREN | FIELD_PREP(INCURRINT, val);
+	} else if (ret != -EINVAL) {
+		dev_warn(dev, "phy%d: invalid st,current-boost-microamp value\n", index);
+	}
+
+	if (!ofnode_read_bool(node, "st,no-lsfs-fb-cap"))
+		tune |= LFSCAPEN;
+
+	if (ofnode_read_bool(node, "st,decrease-hs-slew-rate"))
+		tune |= HSDRVSLEW;
+
+	ret = ofnode_read_u32(node, "st,tune-hs-dc-level", &val);
+	if (!ret && val < DC_MAX) {
+		if (val == DC_MINUS_5_TO_7_MV) {
+			tune |= HSDRVDCCUR;
+		} else {
+			val = (val == DC_PLUS_10_TO_14_MV) ? 1 : 0;
+			tune |= HSDRVCURINCR | FIELD_PREP(HSDRVDCLEV, val);
+		}
+	} else if (ret != -EINVAL) {
+		dev_warn(dev, "phy%d: invalid st,tune-hs-dc-level value\n", index);
+	}
+
+	if (ofnode_read_bool(node, "st,enable-fs-rftime-tuning"))
+		tune |= FSDRVRFADJ;
+
+	if (ofnode_read_bool(node, "st,enable-hs-rftime-reduction"))
+		tune |= HSDRVRFRED;
+
+	ret = ofnode_read_u32(node, "st,trim-hs-current", &val);
+	if (!ret && val < CUR_MAX)
+		tune |= FIELD_PREP(HSDRVCHKITRM, val);
+	else if (ret != -EINVAL)
+		dev_warn(dev, "phy%d: invalid st,trim-hs-current value\n", index);
+
+	ret = ofnode_read_u32(node, "st,trim-hs-impedance", &val);
+	if (!ret && val < IMP_MAX)
+		tune |= FIELD_PREP(HSDRVCHKZTRM, val);
+	else if (ret != -EINVAL)
+		dev_warn(dev, "phy%d: invalid trim-hs-impedance value\n", index);
+
+	ret = ofnode_read_u32(node, "st,tune-squelch-level", &val);
+	if (!ret && val < SQLCH_MAX)
+		tune |= FIELD_PREP(SQLCHCTL, val);
+	else if (ret != -EINVAL)
+		dev_warn(dev, "phy%d: invalid st,tune-squelch-level value\n", index);
+
+	if (ofnode_read_bool(node, "st,enable-hs-rx-gain-eq"))
+		tune |= HDRXGNEQEN;
+
+	ret = ofnode_read_u32(node, "st,tune-hs-rx-offset", &val);
+	if (!ret && val < RX_OFFSET_MAX)
+		tune |= FIELD_PREP(HSRXOFF, val);
+	else if (ret != -EINVAL)
+		dev_warn(dev, "phy%d: invalid st,tune-hs-rx-offset value\n", index);
+
+	if (ofnode_read_bool(node, "st,no-hs-ftime-ctrl"))
+		tune |= HSFALLPREEM;
+
+	if (!ofnode_read_bool(node, "st,no-lsfs-sc"))
+		tune |= SHTCCTCTLPROT;
+
+	if (ofnode_read_bool(node, "st,enable-hs-tx-staggering"))
+		tune |= STAGSEL;
+
+	/* Restore OTP compensation code */
+	tune |= FIELD_PREP(OTPCOMP, otpcomp);
+
+	writel(tune, usbphyc->base + reg);
+}
+
 static const struct phy_ops stm32_usbphyc_phy_ops = {
 	.init = stm32_usbphyc_phy_init,
 	.exit = stm32_usbphyc_phy_exit,
@@ -389,6 +552,10 @@ static int stm32_usbphyc_probe(struct udevice *dev)
 				phy_id, ofnode_get_name(node));
 			return -ENOENT;
 		}
+
+		/* Configure phy tuning */
+		stm32_usbphyc_tuning(dev, node, phy_id);
+
 		usbphyc_phy = usbphyc->phys + phy_id;
 		usbphyc_phy->init = false;
 		usbphyc_phy->powered = false;