phy: marvell: a3700: revise the USB3 comphy setting during power on

This commit is based on commit d9899826 by
  zachary <zhangzg@marvell.com>
from u-boot-marvell, see
github.com/MarvellEmbeddedProcessors/u-boot-marvell/commit/d9899826

- According to design specification, the transmitter should be set to high
  impedence mode during electrical idle. Thus transmitter should detect RX
  at high impedence mode also, and delay is needed to accommodate high
  impedence off latency. Otherwise the USB3 will have detection issue that
  most of the time the USB3 device can not be detected at all, or be
  detected as USB2 device sometimes.
  Modified registers: RD005C302h (R181h) (0051h) Lane Configuration 1
  Bit 6: set to 1 to let Tx detect Rx at HiZ mode
  Bit [3:4]: set to 2 to be delayed by 2 clock cycles
  Bit 0: set to 1 to set transmitter to high impedance mode during idle.
- USB3 De-emphasize level of -3.5dB is mandatory, but USB3 MAC selects 0x2
  (emphasize disabled) in the MAC_PHY_TXDEEMPH [1:0], while it is supposed
  to select 0x1(3.5dB emphasize). Thus need to override what comes from
  the MAC(by setting register 0x1c2 bit2 to 0x1) and to configure the
  overridded values of MAC_PHY_TXDEEMPH [1:0] to 0x1(bit15 of register
  0x181 and bit0 of register 0x180).
- According to USB3 application note, need to update below comphy
  registers:
  Set max speed generation to USB3.0 5Gbps(set RD005C04Ah bit[11:10] to 1)
  Set capacitor value to 0xF(set RF005C224 bit[3:0] to 0xF)

Signed-off-by: Marek Behun <marek.behun@nic.cz>
Signed-off-by: Stefan Roese <sr@denx.de>

drivers/phy/marvell/comphy_a3700.c

@@ -349,13 +349,18 @@ static int comphy_usb3_power_up(u32 lane, u32 type, u32 speed, u32 invert)
 	usb3_reg_set16(LANE_CFG0, 0x1, 0xFF, lane);
 
 	/*
-	 * unset BIT0: set Tx Electrical Idle Mode: Transmitter is in
-	 *             low impedance mode during electrical idle
-	 * unset BIT4: set G2 Tx Datapath with no Delayed Latency
-	 * unset BIT6: set Tx Detect Rx Mode at LoZ mode
-	 */
-	usb3_reg_set16(LANE_CFG1, 0x0, 0xFFFF, lane);
-
+	 * Set BIT0: enable transmitter in high impedance mode
+	 * Set BIT[3:4]: delay 2 clock cycles for HiZ off latency
+	 * Set BIT6: Tx detect Rx at HiZ mode
+	 * Unset BIT15: set to 0 to set USB3 De-emphasize level to -3.5db
+	 *              together with bit 0 of COMPHY_REG_LANE_CFG0_ADDR
+	 *              register
+	 */
+	usb3_reg_set16(LANE_CFG1,
+		       tx_det_rx_mode | gen2_tx_data_dly_deft
+		       | tx_elec_idle_mode_en,
+		       prd_txdeemph1_mask | tx_det_rx_mode
+		       | gen2_tx_data_dly_mask | tx_elec_idle_mode_en, lane);
 
 	/* 0xd005c310 = 0x93: set Spread Spectrum Clock Enabled */
 	usb3_reg_set16(LANE_CFG4, bf_spread_spectrum_clock_en, 0x80, lane);
@@ -425,7 +430,17 @@ static int comphy_usb3_power_up(u32 lane, u32 type, u32 speed, u32 invert)
 		usb3_reg_set16(SYNC_PATTERN, phy_rxd_inv, 0, lane);
 
 	/*
-	 * 10. Release SW reset
+	 * 10. Set max speed generation to USB3.0 5Gbps
+	 */
+	usb3_reg_set16(SYNC_MASK_GEN, 0x0400, 0x0C00, lane);
+
+	/*
+	 * 11. Set capacitor value for FFE gain peaking to 0xF
+	 */
+	usb3_reg_set16(GEN3_SETTINGS_3, 0xF, 0xF, lane);
+
+	/*
+	 * 12. Release SW reset
 	 */
 	usb3_reg_set16(GLOB_PHY_CTRL0,
 		       rb_mode_core_clk_freq_sel | rb_mode_pipe_width_32

drivers/phy/marvell/comphy_a3700.h

@@ -141,6 +141,11 @@ static inline void __iomem *phy_addr(enum phy_unit unit, u32 addr)
 
 #define LANE_CFG1			0x181
 #define bf_use_max_pll_rate		BIT(9)
+#define prd_txdeemph1_mask		BIT(15)
+#define tx_det_rx_mode			BIT(6)
+#define gen2_tx_data_dly_deft		(2 << 3)
+#define gen2_tx_data_dly_mask		(BIT(3) | BIT(4))
+#define tx_elec_idle_mode_en		BIT(0)
 
 #define LANE_CFG4			0x188
 #define bf_spread_spectrum_clock_en	BIT(7)