phy: rockchip-pcie: switch to FIELD_PREP_WM16 macro

The era of hand-rolled HIWORD_UPDATE macros is over, at least for those
drivers that use constant masks.

The Rockchip PCIe PHY driver, used on the RK3399, has its own definition
of HIWORD_UPDATE.

Remove it, and replace instances of it with hw_bitfield.h's
FIELD_PREP_WM16. To achieve this, some mask defines are reshuffled, as
FIELD_PREP_WM16 uses the mask as both the mask of bits to write and to
derive the shift amount from in order to shift the value.

In order to ensure that the mask is always a constant, the inst->index
shift is performed after the FIELD_PREP_WM16, as this is a runtime
value.

>From this, we gain compile-time error checking, and in my humble opinion
nicer code, as well as a single definition of this macro across the
entire codebase to aid in code comprehension.

Tested on a RK3399 ROCKPro64, where PCIe still works as expected when
accessing an NVMe drive.

Signed-off-by: Nicolas Frattaroli <nicolas.frattaroli@collabora.com>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Yury Norov (NVIDIA) <yury.norov@gmail.com>

Author: Nicolas Frattaroli

drivers/phy/rockchip/phy-rockchip-pcie.c

@@ -8,6 +8,7 @@
 
 #include <linux/clk.h>
 #include <linux/delay.h>
+#include <linux/hw_bitfield.h>
 #include <linux/io.h>
 #include <linux/mfd/syscon.h>
 #include <linux/module.h>
@@ -18,22 +19,13 @@
 #include <linux/regmap.h>
 #include <linux/reset.h>
 
-/*
- * The higher 16-bit of this register is used for write protection
- * only if BIT(x + 16) set to 1 the BIT(x) can be written.
- */
-#define HIWORD_UPDATE(val, mask, shift) \
-		((val) << (shift) | (mask) << ((shift) + 16))
 
 #define PHY_MAX_LANE_NUM      4
-#define PHY_CFG_DATA_SHIFT    7
-#define PHY_CFG_ADDR_SHIFT    1
-#define PHY_CFG_DATA_MASK     0xf
-#define PHY_CFG_ADDR_MASK     0x3f
+#define PHY_CFG_DATA_MASK     GENMASK(10, 7)
+#define PHY_CFG_ADDR_MASK     GENMASK(6, 1)
 #define PHY_CFG_WR_ENABLE     1
 #define PHY_CFG_WR_DISABLE    0
-#define PHY_CFG_WR_SHIFT      0
-#define PHY_CFG_WR_MASK       1
+#define PHY_CFG_WR_MASK       BIT(0)
 #define PHY_CFG_PLL_LOCK      0x10
 #define PHY_CFG_CLK_TEST      0x10
 #define PHY_CFG_CLK_SCC       0x12
@@ -48,11 +40,7 @@
 #define PHY_LANE_RX_DET_SHIFT 11
 #define PHY_LANE_RX_DET_TH    0x1
 #define PHY_LANE_IDLE_OFF     0x1
-#define PHY_LANE_IDLE_MASK    0x1
-#define PHY_LANE_IDLE_A_SHIFT 3
-#define PHY_LANE_IDLE_B_SHIFT 4
-#define PHY_LANE_IDLE_C_SHIFT 5
-#define PHY_LANE_IDLE_D_SHIFT 6
+#define PHY_LANE_IDLE_MASK    BIT(3)
 
 struct rockchip_pcie_data {
 	unsigned int pcie_conf;
@@ -99,22 +87,14 @@ static inline void phy_wr_cfg(struct rockchip_pcie_phy *rk_phy,
 			      u32 addr, u32 data)
 {
 	regmap_write(rk_phy->reg_base, rk_phy->phy_data->pcie_conf,
-		     HIWORD_UPDATE(data,
-				   PHY_CFG_DATA_MASK,
-				   PHY_CFG_DATA_SHIFT) |
-		     HIWORD_UPDATE(addr,
-				   PHY_CFG_ADDR_MASK,
-				   PHY_CFG_ADDR_SHIFT));
+		     FIELD_PREP_WM16(PHY_CFG_DATA_MASK, data) |
+		     FIELD_PREP_WM16(PHY_CFG_ADDR_MASK, addr));
 	udelay(1);
 	regmap_write(rk_phy->reg_base, rk_phy->phy_data->pcie_conf,
-		     HIWORD_UPDATE(PHY_CFG_WR_ENABLE,
-				   PHY_CFG_WR_MASK,
-				   PHY_CFG_WR_SHIFT));
+		     FIELD_PREP_WM16(PHY_CFG_WR_MASK, PHY_CFG_WR_ENABLE));
 	udelay(1);
 	regmap_write(rk_phy->reg_base, rk_phy->phy_data->pcie_conf,
-		     HIWORD_UPDATE(PHY_CFG_WR_DISABLE,
-				   PHY_CFG_WR_MASK,
-				   PHY_CFG_WR_SHIFT));
+		     FIELD_PREP_WM16(PHY_CFG_WR_MASK, PHY_CFG_WR_DISABLE));
 }
 
 static int rockchip_pcie_phy_power_off(struct phy *phy)
@@ -125,11 +105,9 @@ static int rockchip_pcie_phy_power_off(struct phy *phy)
 
 	guard(mutex)(&rk_phy->pcie_mutex);
 
-	regmap_write(rk_phy->reg_base,
-		     rk_phy->phy_data->pcie_laneoff,
-		     HIWORD_UPDATE(PHY_LANE_IDLE_OFF,
-				   PHY_LANE_IDLE_MASK,
-				   PHY_LANE_IDLE_A_SHIFT + inst->index));
+	regmap_write(rk_phy->reg_base, rk_phy->phy_data->pcie_laneoff,
+		     FIELD_PREP_WM16(PHY_LANE_IDLE_MASK,
+				     PHY_LANE_IDLE_OFF) << inst->index);
 
 	if (--rk_phy->pwr_cnt) {
 		return 0;
@@ -139,11 +117,9 @@ static int rockchip_pcie_phy_power_off(struct phy *phy)
 	if (err) {
 		dev_err(&phy->dev, "assert phy_rst err %d\n", err);
 		rk_phy->pwr_cnt++;
-		regmap_write(rk_phy->reg_base,
-			     rk_phy->phy_data->pcie_laneoff,
-			     HIWORD_UPDATE(!PHY_LANE_IDLE_OFF,
-					   PHY_LANE_IDLE_MASK,
-					   PHY_LANE_IDLE_A_SHIFT + inst->index));
+		regmap_write(rk_phy->reg_base, rk_phy->phy_data->pcie_laneoff,
+			     FIELD_PREP_WM16(PHY_LANE_IDLE_MASK,
+					     !PHY_LANE_IDLE_OFF) << inst->index);
 		return err;
 	}
 
@@ -159,11 +135,9 @@ static int rockchip_pcie_phy_power_on(struct phy *phy)
 
 	guard(mutex)(&rk_phy->pcie_mutex);
 
-	regmap_write(rk_phy->reg_base,
-		     rk_phy->phy_data->pcie_laneoff,
-		     HIWORD_UPDATE(!PHY_LANE_IDLE_OFF,
-				   PHY_LANE_IDLE_MASK,
-				   PHY_LANE_IDLE_A_SHIFT + inst->index));
+	regmap_write(rk_phy->reg_base, rk_phy->phy_data->pcie_laneoff,
+		     FIELD_PREP_WM16(PHY_LANE_IDLE_MASK,
+				     !PHY_LANE_IDLE_OFF) << inst->index);
 
 	if (rk_phy->pwr_cnt++) {
 		return 0;
@@ -177,9 +151,7 @@ static int rockchip_pcie_phy_power_on(struct phy *phy)
 	}
 
 	regmap_write(rk_phy->reg_base, rk_phy->phy_data->pcie_conf,
-		     HIWORD_UPDATE(PHY_CFG_PLL_LOCK,
-				   PHY_CFG_ADDR_MASK,
-				   PHY_CFG_ADDR_SHIFT));
+		     FIELD_PREP_WM16(PHY_CFG_ADDR_MASK, PHY_CFG_PLL_LOCK));
 
 	/*
 	 * No documented timeout value for phy operation below,
@@ -210,9 +182,7 @@ static int rockchip_pcie_phy_power_on(struct phy *phy)
 	}
 
 	regmap_write(rk_phy->reg_base, rk_phy->phy_data->pcie_conf,
-		     HIWORD_UPDATE(PHY_CFG_PLL_LOCK,
-				   PHY_CFG_ADDR_MASK,
-				   PHY_CFG_ADDR_SHIFT));
+		     FIELD_PREP_WM16(PHY_CFG_ADDR_MASK, PHY_CFG_PLL_LOCK));
 
 	err = regmap_read_poll_timeout(rk_phy->reg_base,
 				       rk_phy->phy_data->pcie_status,