[PATCH RFC net-next] net: stmmac: qcom-ethqos: convert register field updates

Russell King (Oracle) rmk+kernel at armlinux.org.uk
Fri Feb 6 12:31:02 PST 2026


Convert the register field update values to something more recognisable
to a human.

For example, using (BIT(29) | BIT(27)) to update a register field that
consists of bits 29:27 is just a way of obfuscating the constant so
the bare constant doesn't attract review comments.

Worse still is BIT(12) | GENMASK(9, 8), which is used to hide the
decimal value 19 for the bitfield 16:8.

Fix these, and a few others by using FIELD_PREP(). Yes, it means we
have bare numeric constants, but that's way more preferable than
having them obfuscated away.

Signed-off-by: Russell King (Oracle) <rmk+kernel at armlinux.org.uk>
---
 .../stmicro/stmmac/dwmac-qcom-ethqos.c        | 23 ++++++++++++-------
 1 file changed, 15 insertions(+), 8 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-qcom-ethqos.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-qcom-ethqos.c
index af8204c0e188..5ee2a6ee5840 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-qcom-ethqos.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-qcom-ethqos.c
@@ -361,10 +361,12 @@ static int ethqos_dll_configure(struct qcom_ethqos *ethqos)
 			      SDCC_HC_REG_DLL_CONFIG2);
 
 		rgmii_updatel(ethqos, SDCC_DLL_CONFIG2_MCLK_FREQ_CALC,
-			      0x1A << 10, SDCC_HC_REG_DLL_CONFIG2);
+			      FIELD_PREP(SDCC_DLL_CONFIG2_MCLK_FREQ_CALC, 26),
+			      SDCC_HC_REG_DLL_CONFIG2);
 
 		rgmii_updatel(ethqos, SDCC_DLL_CONFIG2_DDR_TRAFFIC_INIT_SEL,
-			      BIT(2), SDCC_HC_REG_DLL_CONFIG2);
+			      FIELD_PREP(SDCC_DLL_CONFIG2_DDR_TRAFFIC_INIT_SEL,
+					 1), SDCC_HC_REG_DLL_CONFIG2);
 
 		rgmii_setmask(ethqos, SDCC_DLL_CONFIG2_DDR_TRAFFIC_INIT_SW,
 			      SDCC_HC_REG_DLL_CONFIG2);
@@ -425,11 +427,13 @@ static int ethqos_rgmii_macro_init(struct qcom_ethqos *ethqos, int speed)
 		if (ethqos->has_emac_ge_3) {
 			/* 0.9 ns */
 			rgmii_updatel(ethqos, SDCC_DDR_CONFIG_PRG_RCLK_DLY,
-				      115, SDCC_HC_REG_DDR_CONFIG);
+				      FIELD_PREP(SDCC_DDR_CONFIG_PRG_RCLK_DLY,
+						 115), SDCC_HC_REG_DDR_CONFIG);
 		} else {
 			/* 1.8 ns */
 			rgmii_updatel(ethqos, SDCC_DDR_CONFIG_PRG_RCLK_DLY,
-				      57, SDCC_HC_REG_DDR_CONFIG);
+				      FIELD_PREP(SDCC_DDR_CONFIG_PRG_RCLK_DLY,
+						 57), SDCC_HC_REG_DDR_CONFIG);
 		}
 		rgmii_setmask(ethqos, SDCC_DDR_CONFIG_PRG_DLY_EN,
 			      SDCC_HC_REG_DDR_CONFIG);
@@ -451,7 +455,8 @@ static int ethqos_rgmii_macro_init(struct qcom_ethqos *ethqos, int speed)
 		rgmii_updatel(ethqos, RGMII_CONFIG2_TX_CLK_PHASE_SHIFT_EN,
 			      phase_shift, RGMII_IO_MACRO_CONFIG2);
 		rgmii_updatel(ethqos, RGMII_CONFIG_MAX_SPD_PRG_2,
-			      BIT(6), RGMII_IO_MACRO_CONFIG);
+			      FIELD_PREP(RGMII_CONFIG_MAX_SPD_PRG_2, 1),
+			      RGMII_IO_MACRO_CONFIG);
 		rgmii_clrmask(ethqos, RGMII_CONFIG2_RSVD_CONFIG15,
 			      RGMII_IO_MACRO_CONFIG2);
 
@@ -464,7 +469,8 @@ static int ethqos_rgmii_macro_init(struct qcom_ethqos *ethqos, int speed)
 
 		/* Write 0x5 to PRG_RCLK_DLY_CODE */
 		rgmii_updatel(ethqos, SDCC_DDR_CONFIG_EXT_PRG_RCLK_DLY_CODE,
-			      (BIT(29) | BIT(27)), SDCC_HC_REG_DDR_CONFIG);
+			      FIELD_PREP(SDCC_DDR_CONFIG_EXT_PRG_RCLK_DLY_CODE,
+					 5), SDCC_HC_REG_DDR_CONFIG);
 		rgmii_setmask(ethqos, SDCC_DDR_CONFIG_EXT_PRG_RCLK_DLY,
 			      SDCC_HC_REG_DDR_CONFIG);
 		rgmii_setmask(ethqos, SDCC_DDR_CONFIG_EXT_PRG_RCLK_DLY_EN,
@@ -487,7 +493,7 @@ static int ethqos_rgmii_macro_init(struct qcom_ethqos *ethqos, int speed)
 		rgmii_updatel(ethqos, RGMII_CONFIG2_TX_CLK_PHASE_SHIFT_EN,
 			      phase_shift, RGMII_IO_MACRO_CONFIG2);
 		rgmii_updatel(ethqos, RGMII_CONFIG_MAX_SPD_PRG_9,
-			      BIT(12) | GENMASK(9, 8),
+			      FIELD_PREP(RGMII_CONFIG_MAX_SPD_PRG_9, 19),
 			      RGMII_IO_MACRO_CONFIG);
 		rgmii_clrmask(ethqos, RGMII_CONFIG2_RSVD_CONFIG15,
 			      RGMII_IO_MACRO_CONFIG2);
@@ -499,7 +505,8 @@ static int ethqos_rgmii_macro_init(struct qcom_ethqos *ethqos, int speed)
 				      RGMII_IO_MACRO_CONFIG2);
 		/* Write 0x5 to PRG_RCLK_DLY_CODE */
 		rgmii_updatel(ethqos, SDCC_DDR_CONFIG_EXT_PRG_RCLK_DLY_CODE,
-			      (BIT(29) | BIT(27)), SDCC_HC_REG_DDR_CONFIG);
+			      FIELD_PREP(SDCC_DDR_CONFIG_EXT_PRG_RCLK_DLY_CODE,
+					 5), SDCC_HC_REG_DDR_CONFIG);
 		rgmii_setmask(ethqos, SDCC_DDR_CONFIG_EXT_PRG_RCLK_DLY,
 			      SDCC_HC_REG_DDR_CONFIG);
 		rgmii_setmask(ethqos, SDCC_DDR_CONFIG_EXT_PRG_RCLK_DLY_EN,
-- 
2.47.3




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