[PATCH v4 03/12] phy: rockchip: samsung-hdptx: Fix clock ratio setup

From: Cristian Ciocaltea
Date: Mon Mar 03 2025 - 20:45:08 EST


The switch from 1/10 to 1/40 clock ratio must happen when exceeding the
340 MHz rate limit of HDMI 1.4, i.e. when entering the HDMI 2.0 domain,
and not before.

While at it, introduce a define for this rate limit constant.

Fixes: 553be2830c5f ("phy: rockchip: Add Samsung HDMI/eDP Combo PHY driver")
Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@xxxxxxxxxxxxx>
---
drivers/phy/rockchip/phy-rockchip-samsung-hdptx.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/phy/rockchip/phy-rockchip-samsung-hdptx.c b/drivers/phy/rockchip/phy-rockchip-samsung-hdptx.c
index f88369864c50e4563834ccbb26f1f9f440e99271..cf2c3a46604cb9d8c26fe5ec8346904e0b62848f 100644
--- a/drivers/phy/rockchip/phy-rockchip-samsung-hdptx.c
+++ b/drivers/phy/rockchip/phy-rockchip-samsung-hdptx.c
@@ -320,6 +320,7 @@
#define LN3_TX_SER_RATE_SEL_HBR2_MASK BIT(3)
#define LN3_TX_SER_RATE_SEL_HBR3_MASK BIT(2)

+#define HDMI14_MAX_RATE 340000000
#define HDMI20_MAX_RATE 600000000

enum dp_link_rate {
@@ -1072,7 +1073,7 @@ static int rk_hdptx_ropll_tmds_mode_config(struct rk_hdptx_phy *hdptx,

regmap_write(hdptx->regmap, LNTOP_REG(0200), 0x06);

- if (rate >= 3400000) {
+ if (rate > HDMI14_MAX_RATE / 100) {
/* For 1/40 bitrate clk */
rk_hdptx_multi_reg_write(hdptx, rk_hdtpx_tmds_lntop_highbr_seq);
} else {

--
2.48.1