phy: cadence: cdns-dphy: Enable lower resolutions in dphy

Enable support for data lane rates between 80-160 Mbps cdns dphy
as mentioned in TRM [0] by setting the pll_opdiv field to 16.
This change enables lower resolutions like 640x480 at 60Hz.

[0]: https://www.ti.com/lit/zip/spruil1
(Table 12-552. DPHY_TX_PLL_CTRL Register Field Descriptions)

Reviewed-by: Udit Kumar <u-kumar1@ti.com>
Reviewed-by: Devarsh Thakkar <devarsht@ti.com>
Signed-off-by: Harikrishna Shenoy <h-shenoy@ti.com>
Link: https://lore.kernel.org/r/20250807052002.717807-1-h-shenoy@ti.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

diff --git a/drivers/phy/cadence/cdns-dphy.c b/drivers/phy/cadence/cdns-dphy.c
index 24a25606996cb7e78cf467c58ba008b586563266..d5b0e516b93c0f756ac4bc0129f918949301ba0b 100644 (file)
--- a/drivers/phy/cadence/cdns-dphy.c
+++ b/drivers/phy/cadence/cdns-dphy.c
@@ -136,7 +136,7 @@ static int cdns_dphy_get_pll_cfg(struct cdns_dphy *dphy,
 
        dlane_bps = opts->hs_clk_rate;
 
-       if (dlane_bps > 2500000000UL || dlane_bps < 160000000UL)
+       if (dlane_bps > 2500000000UL || dlane_bps < 80000000UL)
                return -EINVAL;
        else if (dlane_bps >= 1250000000)
                cfg->pll_opdiv = 1;
@@ -146,6 +146,8 @@ static int cdns_dphy_get_pll_cfg(struct cdns_dphy *dphy,
                cfg->pll_opdiv = 4;
        else if (dlane_bps >= 160000000)
                cfg->pll_opdiv = 8;
+       else if (dlane_bps >= 80000000)
+               cfg->pll_opdiv = 16;
 
        cfg->pll_fbdiv = DIV_ROUND_UP_ULL(dlane_bps * 2 * cfg->pll_opdiv *
                                          cfg->pll_ipdiv,