Re: [PATCH 3/4] phy: fsl-imx8mq-usb: support alternate reference clock
From: Frank Li <Frank.li@nxp.com>
Date: 2025-09-19 15:58:08
Also in:
imx, linux-clk, linux-devicetree, linux-phy, lkml
On Fri, Sep 19, 2025 at 03:02:59PM +0800, Xu Yang wrote:
This phy supports both 24MHz and 100MHz clock inputs. By default it's using XTAL 24MHz and the 100MHz clock is a alternate reference clock. Add supports to use alternate reference clock in case 24MHz clock can't work well. Signed-off-by: Xu Yang <xu.yang_2@nxp.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
quoted hunk ↗ jump to hunk
--- drivers/phy/freescale/phy-fsl-imx8mq-usb.c | 23 +++++++++++++++++++++-- 1 file changed, 21 insertions(+), 2 deletions(-)diff --git a/drivers/phy/freescale/phy-fsl-imx8mq-usb.c b/drivers/phy/freescale/phy-fsl-imx8mq-usb.c index b94f242420fc733cd75abef8ba1cd4f59ac18eb5..ad8a55012e42f2c15496955d00c6d5fd85c5beb2 100644 --- a/drivers/phy/freescale/phy-fsl-imx8mq-usb.c +++ b/drivers/phy/freescale/phy-fsl-imx8mq-usb.c@@ -16,6 +16,7 @@ #define PHY_CTRL0_REF_SSP_EN BIT(2) #define PHY_CTRL0_FSEL_MASK GENMASK(10, 5) #define PHY_CTRL0_FSEL_24M 0x2a +#define PHY_CTRL0_FSEL_100M 0x27 #define PHY_CTRL1 0x4 #define PHY_CTRL1_RESET BIT(0)@@ -108,6 +109,7 @@ struct tca_blk { struct imx8mq_usb_phy { struct phy *phy; struct clk *clk; + struct clk *alt_clk; void __iomem *base; struct regulator *vbus; struct tca_blk *tca;@@ -582,7 +584,8 @@ static int imx8mp_usb_phy_init(struct phy *phy) /* USB3.0 PHY signal fsel for 24M ref */ value = readl(imx_phy->base + PHY_CTRL0); value &= ~PHY_CTRL0_FSEL_MASK; - value |= FIELD_PREP(PHY_CTRL0_FSEL_MASK, PHY_CTRL0_FSEL_24M); + value |= FIELD_PREP(PHY_CTRL0_FSEL_MASK, imx_phy->alt_clk ? + PHY_CTRL0_FSEL_100M : PHY_CTRL0_FSEL_24M); writel(value, imx_phy->base + PHY_CTRL0); /* Disable alt_clk_en and use internal MPLL clocks */@@ -626,13 +629,24 @@ static int imx8mq_phy_power_on(struct phy *phy) if (ret) return ret; - return clk_prepare_enable(imx_phy->clk); + ret = clk_prepare_enable(imx_phy->clk); + if (ret) + return ret; + + ret = clk_prepare_enable(imx_phy->alt_clk); + if (ret) { + clk_disable_unprepare(imx_phy->clk); + return ret; + } + + return ret; } static int imx8mq_phy_power_off(struct phy *phy) { struct imx8mq_usb_phy *imx_phy = phy_get_drvdata(phy); + clk_disable_unprepare(imx_phy->alt_clk); clk_disable_unprepare(imx_phy->clk); regulator_disable(imx_phy->vbus);@@ -681,6 +695,11 @@ static int imx8mq_usb_phy_probe(struct platform_device *pdev) return PTR_ERR(imx_phy->clk); } + imx_phy->alt_clk = devm_clk_get_optional(dev, "alt"); + if (IS_ERR(imx_phy->alt_clk)) + return dev_err_probe(dev, PTR_ERR(imx_phy->alt_clk), + "Failed to get alt clk\n"); + imx_phy->base = devm_platform_ioremap_resource(pdev, 0); if (IS_ERR(imx_phy->base)) return PTR_ERR(imx_phy->base); --2.34.1