Linux-PHY Archive on lore.kernel.org

* [PATCH v5 2/6] phy: realtek: usb2: introduce read and write functions to driver data
From: Rustam Adilov @ 2026-04-20 19:19 UTC (permalink / raw)
  To: Vinod Koul, Neil Armstrong, Rob Herring, Krzysztof Kozlowski,
	Conor Dooley, Stanley Chang, linux-phy, devicetree, linux-kernel
  Cc: Rustam Adilov, Michael Zavertkin
In-Reply-To: <20260420191941.81834-1-adilov@disroot.org>

RTL9607C is a big endian SoC but has little endian USB host controller and
thus, reads and writes to the reg_gusb2phyacc0 should go through
le32_to_cpu and cpu_to_le32 functions respectively. This doesn't apply to
vstatus register though as it is in the different register region compared
to USB host controller region.

The reason is readl/writel functions, despite the supposed little endian
byte swap, still operate with native endian and this is because RTL9607C
is MIPS and here readl/writel are native unless SWAP_IO_SPACE is enabled.
Enabling SWAP_IO_SPACE results in boot hangs so that is not an option.
And so wrapping them around le32 makes a proper byte swap from big endian
to little endian.

To handle this situation, introduce read and write functions to the driver
data and create a default variation of read and write function for the
current RTD SoCs.

Adjust all instances of utmi_wait_register function to now include the read
function as one of its arguments.

Assign the existing phy configuration for RTD SoCs to the default read
and write functions.

Co-developed-by: Michael Zavertkin <misha.zavertkin@mail.ru>
Signed-off-by: Michael Zavertkin <misha.zavertkin@mail.ru>
Signed-off-by: Rustam Adilov <adilov@disroot.org>
---
 drivers/phy/realtek/phy-rtk-usb2.c | 63 ++++++++++++++++++++++++------
 1 file changed, 50 insertions(+), 13 deletions(-)

diff --git a/drivers/phy/realtek/phy-rtk-usb2.c b/drivers/phy/realtek/phy-rtk-usb2.c
index f5f943518d4f..19297a42a841 100644
--- a/drivers/phy/realtek/phy-rtk-usb2.c
+++ b/drivers/phy/realtek/phy-rtk-usb2.c
@@ -67,6 +67,9 @@ struct phy_reg {
 	int vstatus_offset;
 	u32 vstatus_busy;
 	u32 new_reg_req;
+
+	u32 (*read)(void __iomem *reg);
+	void (*write)(u32 val, void __iomem *reg);
 };
 
 struct phy_data {
@@ -102,6 +105,9 @@ struct phy_cfg {
 	int vstatus_offset;
 	u32 vstatus_busy;
 	u32 new_reg_req;
+
+	u32 (*read)(void __iomem *reg);
+	void (*write)(u32 val, void __iomem *reg);
 };
 
 struct phy_parameter {
@@ -128,6 +134,16 @@ struct rtk_phy {
 	struct dentry *debug_dir;
 };
 
+static u32 rtk_usb2phy_read(void __iomem *reg)
+{
+	return readl(reg);
+}
+
+static void rtk_usb2phy_write(u32 val, void __iomem *reg)
+{
+	writel(val, reg);
+}
+
 /* mapping 0xE0 to 0 ... 0xE7 to 7, 0xF0 to 8 ,,, 0xF7 to 15 */
 static inline int page_addr_to_array_index(u8 addr)
 {
@@ -144,12 +160,13 @@ static inline u8 array_index_to_page_addr(int index)
 #define PHY_IO_TIMEOUT_USEC		(50000)
 #define PHY_IO_DELAY_US			(100)
 
-static inline int utmi_wait_register(void __iomem *reg, u32 mask, u32 result)
+static inline int utmi_wait_register(u32 (*read)(void __iomem *reg), void __iomem *reg, u32 mask,
+				     u32 result)
 {
 	int ret;
 	unsigned int val;
 
-	ret = read_poll_timeout(readl, val, ((val & mask) == result),
+	ret = read_poll_timeout(read, val, ((val & mask) == result),
 				PHY_IO_DELAY_US, PHY_IO_TIMEOUT_USEC, false, reg);
 	if (ret) {
 		pr_err("%s can't program USB phy\n", __func__);
@@ -168,25 +185,25 @@ static char rtk_phy_read(struct phy_reg *phy_reg, char addr)
 	addr -= OFFEST_PHY_READ;
 
 	/* polling until VBusy == 0 */
-	ret = utmi_wait_register(reg_gusb2phyacc0, phy_reg->vstatus_busy, 0);
+	ret = utmi_wait_register(phy_reg->read, reg_gusb2phyacc0, phy_reg->vstatus_busy, 0);
 	if (ret)
 		return (char)ret;
 
 	/* VCtrl = low nibble of addr, and set phy_reg->new_reg_req */
 	val = phy_reg->new_reg_req | (GET_LOW_NIBBLE(addr) << PHY_VCTRL_SHIFT);
-	writel(val, reg_gusb2phyacc0);
-	ret = utmi_wait_register(reg_gusb2phyacc0, phy_reg->vstatus_busy, 0);
+	phy_reg->write(val, reg_gusb2phyacc0);
+	ret = utmi_wait_register(phy_reg->read, reg_gusb2phyacc0, phy_reg->vstatus_busy, 0);
 	if (ret)
 		return (char)ret;
 
 	/* VCtrl = high nibble of addr, and set phy_reg->new_reg_req */
 	val = phy_reg->new_reg_req | (GET_HIGH_NIBBLE(addr) << PHY_VCTRL_SHIFT);
-	writel(val, reg_gusb2phyacc0);
-	ret = utmi_wait_register(reg_gusb2phyacc0, phy_reg->vstatus_busy, 0);
+	phy_reg->write(val, reg_gusb2phyacc0);
+	ret = utmi_wait_register(phy_reg->read, reg_gusb2phyacc0, phy_reg->vstatus_busy, 0);
 	if (ret)
 		return (char)ret;
 
-	val = readl(reg_gusb2phyacc0);
+	val = phy_reg->read(reg_gusb2phyacc0);
 
 	return (char)(val & PHY_REG_DATA_MASK);
 }
@@ -202,23 +219,23 @@ static int rtk_phy_write(struct phy_reg *phy_reg, char addr, char data)
 	/* write data to VStatusOut2 (data output to phy) */
 	writel((u32)data << shift_bits, reg_wrap_vstatus + phy_reg->vstatus_offset);
 
-	ret = utmi_wait_register(reg_gusb2phyacc0, phy_reg->vstatus_busy, 0);
+	ret = utmi_wait_register(phy_reg->read, reg_gusb2phyacc0, phy_reg->vstatus_busy, 0);
 	if (ret)
 		return ret;
 
 	/* VCtrl = low nibble of addr, set phy_reg->new_reg_req */
 	val = phy_reg->new_reg_req | (GET_LOW_NIBBLE(addr) << PHY_VCTRL_SHIFT);
 
-	writel(val, reg_gusb2phyacc0);
-	ret = utmi_wait_register(reg_gusb2phyacc0, phy_reg->vstatus_busy, 0);
+	phy_reg->write(val, reg_gusb2phyacc0);
+	ret = utmi_wait_register(phy_reg->read, reg_gusb2phyacc0, phy_reg->vstatus_busy, 0);
 	if (ret)
 		return ret;
 
 	/* VCtrl = high nibble of addr, set phy_reg->new_reg_req */
 	val = phy_reg->new_reg_req | (GET_HIGH_NIBBLE(addr) << PHY_VCTRL_SHIFT);
 
-	writel(val, reg_gusb2phyacc0);
-	ret = utmi_wait_register(reg_gusb2phyacc0, phy_reg->vstatus_busy, 0);
+	phy_reg->write(val, reg_gusb2phyacc0);
+	ret = utmi_wait_register(phy_reg->read, reg_gusb2phyacc0, phy_reg->vstatus_busy, 0);
 	if (ret)
 		return ret;
 
@@ -984,6 +1001,8 @@ static int parse_phy_data(struct rtk_phy *rtk_phy)
 		phy_parameter->phy_reg.vstatus_offset = phy_cfg->vstatus_offset;
 		phy_parameter->phy_reg.vstatus_busy = phy_cfg->vstatus_busy;
 		phy_parameter->phy_reg.new_reg_req = phy_cfg->new_reg_req;
+		phy_parameter->phy_reg.read = phy_cfg->read;
+		phy_parameter->phy_reg.write = phy_cfg->write;
 
 		if (of_property_read_bool(np, "realtek,inverse-hstx-sync-clock"))
 			phy_parameter->inverse_hstx_sync_clock = true;
@@ -1098,6 +1117,8 @@ static const struct phy_cfg rtd1295_phy_cfg = {
 	.vstatus_offset = 0,
 	.vstatus_busy = PHY_VSTS_BUSY,
 	.new_reg_req = PHY_NEW_REG_REQ,
+	.read = rtk_usb2phy_read,
+	.write = rtk_usb2phy_write,
 };
 
 static const struct phy_cfg rtd1395_phy_cfg = {
@@ -1125,6 +1146,8 @@ static const struct phy_cfg rtd1395_phy_cfg = {
 	.vstatus_offset = 0,
 	.vstatus_busy = PHY_VSTS_BUSY,
 	.new_reg_req = PHY_NEW_REG_REQ,
+	.read = rtk_usb2phy_read,
+	.write = rtk_usb2phy_write,
 };
 
 static const struct phy_cfg rtd1395_phy_cfg_2port = {
@@ -1152,6 +1175,8 @@ static const struct phy_cfg rtd1395_phy_cfg_2port = {
 	.vstatus_offset = 0,
 	.vstatus_busy = PHY_VSTS_BUSY,
 	.new_reg_req = PHY_NEW_REG_REQ,
+	.read = rtk_usb2phy_read,
+	.write = rtk_usb2phy_write,
 };
 
 static const struct phy_cfg rtd1619_phy_cfg = {
@@ -1177,6 +1202,8 @@ static const struct phy_cfg rtd1619_phy_cfg = {
 	.vstatus_offset = 0,
 	.vstatus_busy = PHY_VSTS_BUSY,
 	.new_reg_req = PHY_NEW_REG_REQ,
+	.read = rtk_usb2phy_read,
+	.write = rtk_usb2phy_write,
 };
 
 static const struct phy_cfg rtd1319_phy_cfg = {
@@ -1206,6 +1233,8 @@ static const struct phy_cfg rtd1319_phy_cfg = {
 	.vstatus_offset = 0,
 	.vstatus_busy = PHY_VSTS_BUSY,
 	.new_reg_req = PHY_NEW_REG_REQ,
+	.read = rtk_usb2phy_read,
+	.write = rtk_usb2phy_write,
 };
 
 static const struct phy_cfg rtd1312c_phy_cfg = {
@@ -1234,6 +1263,8 @@ static const struct phy_cfg rtd1312c_phy_cfg = {
 	.vstatus_offset = 0,
 	.vstatus_busy = PHY_VSTS_BUSY,
 	.new_reg_req = PHY_NEW_REG_REQ,
+	.read = rtk_usb2phy_read,
+	.write = rtk_usb2phy_write,
 };
 
 static const struct phy_cfg rtd1619b_phy_cfg = {
@@ -1262,6 +1293,8 @@ static const struct phy_cfg rtd1619b_phy_cfg = {
 	.vstatus_offset = 0,
 	.vstatus_busy = PHY_VSTS_BUSY,
 	.new_reg_req = PHY_NEW_REG_REQ,
+	.read = rtk_usb2phy_read,
+	.write = rtk_usb2phy_write,
 };
 
 static const struct phy_cfg rtd1319d_phy_cfg = {
@@ -1290,6 +1323,8 @@ static const struct phy_cfg rtd1319d_phy_cfg = {
 	.vstatus_offset = 0,
 	.vstatus_busy = PHY_VSTS_BUSY,
 	.new_reg_req = PHY_NEW_REG_REQ,
+	.read = rtk_usb2phy_read,
+	.write = rtk_usb2phy_write,
 };
 
 static const struct phy_cfg rtd1315e_phy_cfg = {
@@ -1319,6 +1354,8 @@ static const struct phy_cfg rtd1315e_phy_cfg = {
 	.vstatus_offset = 0,
 	.vstatus_busy = PHY_VSTS_BUSY,
 	.new_reg_req = PHY_NEW_REG_REQ,
+	.read = rtk_usb2phy_read,
+	.write = rtk_usb2phy_write,
 };
 
 static const struct of_device_id usbphy_rtk_dt_match[] = {
-- 
2.53.0


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