From: Devarsh Thakkar Date: Fri, 4 Jul 2025 12:59:15 +0000 (+0530) Subject: phy: cadence: cdns-dphy: Update calibration wait time for startup state machine X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=2c27aaee934a1b5229152fe33a14f1fdf50da143;p=users%2Fhch%2Fmisc.git phy: cadence: cdns-dphy: Update calibration wait time for startup state machine Do read-modify-write so that we re-use the characterized reset value as specified in TRM [1] to program calibration wait time which defines number of cycles to wait for after startup state machine is in bandgap enable state. This fixes PLL lock timeout error faced while using RPi DSI Panel on TI's AM62L and J721E SoC since earlier calibration wait time was getting overwritten to zero value thus failing the PLL to lockup and causing timeout. [1] AM62P TRM (Section 14.8.6.3.2.1.1 DPHY_TX_DPHYTX_CMN0_CMN_DIG_TBIT2): Link: https://www.ti.com/lit/pdf/spruj83 Cc: stable@vger.kernel.org Fixes: 7a343c8bf4b5 ("phy: Add Cadence D-PHY support") Signed-off-by: Devarsh Thakkar Tested-by: Harikrishna Shenoy Reviewed-by: Tomi Valkeinen Link: https://lore.kernel.org/r/20250704125915.1224738-3-devarsht@ti.com Signed-off-by: Vinod Koul --- diff --git a/drivers/phy/cadence/cdns-dphy.c b/drivers/phy/cadence/cdns-dphy.c index da8de0a9d086..24a25606996c 100644 --- a/drivers/phy/cadence/cdns-dphy.c +++ b/drivers/phy/cadence/cdns-dphy.c @@ -30,6 +30,7 @@ #define DPHY_CMN_SSM DPHY_PMA_CMN(0x20) #define DPHY_CMN_SSM_EN BIT(0) +#define DPHY_CMN_SSM_CAL_WAIT_TIME GENMASK(8, 1) #define DPHY_CMN_TX_MODE_EN BIT(9) #define DPHY_CMN_PWM DPHY_PMA_CMN(0x40) @@ -410,7 +411,8 @@ static int cdns_dphy_power_on(struct phy *phy) writel(reg, dphy->regs + DPHY_BAND_CFG); /* Start TX state machine. */ - writel(DPHY_CMN_SSM_EN | DPHY_CMN_TX_MODE_EN, + reg = readl(dphy->regs + DPHY_CMN_SSM); + writel((reg & DPHY_CMN_SSM_CAL_WAIT_TIME) | DPHY_CMN_SSM_EN | DPHY_CMN_TX_MODE_EN, dphy->regs + DPHY_CMN_SSM); ret = cdns_dphy_wait_for_pll_lock(dphy);