[PATCH v3] phy: mvebu-cp110-utmi: support swapping d+/d- lanes by dts property

From: Josua Mayer
Date: Sun Sep 08 2024 - 04:35:04 EST


CP11x UTMI PHY supports swapping D+/D- signals via digital control
register 1.

Add support for the "swap-dx-lanes" device-tree property, which lists
the port-ids that should swap D+ and D-.
The property is evaluated in probe and applied before power-on
during mvebu_cp110_utmi_port_setup.

Signed-off-by: Josua Mayer <josua@xxxxxxxxxxxxx>
---
Changes in v3:
- add description for new struct member
(Reported-by: kernel test robot <lkp@xxxxxxxxx>)
- Link to v2: https://lore.kernel.org/r/20240903-mvebu-utmi-phy-v2-1-7f49c131fad0@xxxxxxxxxxxxx

Changes in v2:
- fixed compile error introduced with v6.11-rc1:
parameters of of_property_for_each_u32 were changed from 5 to 3.
(Reported-by: Vinod Koul <vkoul@xxxxxxxxxx>)
- rebased on v6.11-rc1
- Link to v1: https://lore.kernel.org/r/20240704-mvebu-utmi-phy-v1-1-9d3c8eea46e5@xxxxxxxxxxxxx
---
drivers/phy/marvell/phy-mvebu-cp110-utmi.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)

diff --git a/drivers/phy/marvell/phy-mvebu-cp110-utmi.c b/drivers/phy/marvell/phy-mvebu-cp110-utmi.c
index 4922a5f3327d..59903f86b13f 100644
--- a/drivers/phy/marvell/phy-mvebu-cp110-utmi.c
+++ b/drivers/phy/marvell/phy-mvebu-cp110-utmi.c
@@ -62,6 +62,8 @@
#define SQ_AMP_CAL_MASK GENMASK(2, 0)
#define SQ_AMP_CAL_VAL 1
#define SQ_AMP_CAL_EN BIT(3)
+#define UTMI_DIG_CTRL1_REG 0x20
+#define SWAP_DPDM BIT(15)
#define UTMI_CTRL_STATUS0_REG 0x24
#define SUSPENDM BIT(22)
#define TEST_SEL BIT(25)
@@ -99,11 +101,13 @@ struct mvebu_cp110_utmi {
* @priv: PHY driver data
* @id: PHY port ID
* @dr_mode: PHY connection: USB_DR_MODE_HOST or USB_DR_MODE_PERIPHERAL
+ * @swap_dx: whether to swap d+/d- signals
*/
struct mvebu_cp110_utmi_port {
struct mvebu_cp110_utmi *priv;
u32 id;
enum usb_dr_mode dr_mode;
+ bool swap_dx;
};

static void mvebu_cp110_utmi_port_setup(struct mvebu_cp110_utmi_port *port)
@@ -159,6 +163,13 @@ static void mvebu_cp110_utmi_port_setup(struct mvebu_cp110_utmi_port *port)
reg &= ~(VDAT_MASK | VSRC_MASK);
reg |= (VDAT_VAL << VDAT_OFFSET) | (VSRC_VAL << VSRC_OFFSET);
writel(reg, PORT_REGS(port) + UTMI_CHGDTC_CTRL_REG);
+
+ /* Swap D+/D- */
+ reg = readl(PORT_REGS(port) + UTMI_DIG_CTRL1_REG);
+ reg &= ~(SWAP_DPDM);
+ if (port->swap_dx)
+ reg |= SWAP_DPDM;
+ writel(reg, PORT_REGS(port) + UTMI_DIG_CTRL1_REG);
}

static int mvebu_cp110_utmi_phy_power_off(struct phy *phy)
@@ -286,6 +297,7 @@ static int mvebu_cp110_utmi_phy_probe(struct platform_device *pdev)
struct phy_provider *provider;
struct device_node *child;
u32 usb_devices = 0;
+ u32 swap_dx = 0;

utmi = devm_kzalloc(dev, sizeof(*utmi), GFP_KERNEL);
if (!utmi)
@@ -345,6 +357,10 @@ static int mvebu_cp110_utmi_phy_probe(struct platform_device *pdev)
}
}

+ of_property_for_each_u32(dev->of_node, "swap-dx-lanes", swap_dx)
+ if (swap_dx == port_id)
+ port->swap_dx = 1;
+
/* Retrieve PHY capabilities */
utmi->ops = &mvebu_cp110_utmi_phy_ops;


---
base-commit: 8400291e289ee6b2bf9779ff1c83a291501f017b
change-id: 20240704-mvebu-utmi-phy-84aa3bf3957d

Best regards,
--
Josua Mayer <josua@xxxxxxxxxxxxx>