[PATCH v2 1/6] usb: phy: mxs: enable regulator phy-3p0 to improve signal qualilty

Xu Yang
2024-07-26T11:32:49Z

Enable regulator 'phy-3p0' to pass eye diagram test since it improve signal
qualilty.

Signed-off-by: Xu Yang <xu.yang_2@nxp.com>

---
Changes in v2:
- rewrite commit message
- use dev_err_probe() as suggested by Frank Li
---
drivers/usb/phy/phy-mxs-usb.c | 26 ++++++++++++++++++++++++++
1 file changed, 26 insertions(+)

diff --git a/drivers/usb/phy/phy-mxs-usb.c b/drivers/usb/phy/phy-mxs-usb.c
index 920a32cd094d..d9d29f0b37de 100644
--- a/drivers/usb/phy/phy-mxs-usb.c
+++ b/drivers/usb/phy/phy-mxs-usb.c
@@ -18,6 +18,7 @@
#include <linux/regmap.h>
#include <linux/mfd/syscon.h>
#include <linux/iopoll.h>
+#include <linux/regulator/consumer.h>

#define DRIVER_NAME "mxs_phy"

@@ -204,6 +205,7 @@ struct mxs_phy {
int port_id;
u32 tx_reg_set;
u32 tx_reg_mask;
+ struct regulator *phy_3p0;
};

static inline bool is_imx6q_phy(struct mxs_phy *mxs_phy)
@@ -288,6 +290,16 @@ static int mxs_phy_hw_init(struct mxs_phy *mxs_phy)
if (ret)
goto disable_pll;

+ if (mxs_phy->phy_3p0) {
+ ret = regulator_enable(mxs_phy->phy_3p0);
+ if (ret) {
+ dev_err(mxs_phy->phy.dev,
+ "Failed to enable 3p0 regulator, ret=%d\n",
+ ret);
+ return ret;
+ }
+ }
+
/* Power up the PHY */
writel(0, base + HW_USBPHY_PWD);

@@ -448,6 +460,9 @@ static void mxs_phy_shutdown(struct usb_phy *phy)
if (is_imx7ulp_phy(mxs_phy))
mxs_phy_pll_enable(phy->io_priv, false);

+ if (mxs_phy->phy_3p0)
+ regulator_disable(mxs_phy->phy_3p0);
+
clk_disable_unprepare(mxs_phy->clk);
}

@@ -789,6 +804,17 @@ static int mxs_phy_probe(struct platform_device *pdev)
mxs_phy->clk = clk;
mxs_phy->data = of_device_get_match_data(&pdev->dev);

+ mxs_phy->phy_3p0 = devm_regulator_get(&pdev->dev, "phy-3p0");
+ if (PTR_ERR(mxs_phy->phy_3p0) == -ENODEV)
+ /* not exist */
+ mxs_phy->phy_3p0 = NULL;
+ else if (IS_ERR(mxs_phy->phy_3p0))
+ return dev_err_probe(&pdev->dev, PTR_ERR(mxs_phy->phy_3p0),
+ "Getting regulator error\n");
+
+ if (mxs_phy->phy_3p0)
+ regulator_set_voltage(mxs_phy->phy_3p0, 3200000, 3200000);
+
platform_set_drvdata(pdev, mxs_phy);

device_set_wakeup_capable(&pdev->dev, true);
--
2.34.1