phy: phy-rockchip-inno-usb2: add rk3588 phy tuning support

On RK3588 some registers need to be tweaked to support waking up from
suspend when a USB device is plugged into a port from a suspended PHY.
Without this change USB devices only work when they are plugged at
boot time.

Apart from that it optimizes settings to avoid devices toggling
between fullspeed and highspeed mode.
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Link: https://lore.kernel.org/r/20230522170324.61349-5-sebastian.reichel@collabora.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

drivers/phy/rockchip/phy-rockchip-inno-usb2.c

@@ -33,6 +33,8 @@
 #define SCHEDULE_DELAY		(60 * HZ)
 #define OTG_SCHEDULE_DELAY	(2 * HZ)
 
+struct rockchip_usb2phy;
+
 enum rockchip_usb2phy_port_id {
 	USB2PHY_PORT_OTG,
 	USB2PHY_PORT_HOST,
@@ -163,6 +165,7 @@ struct rockchip_usb2phy_port_cfg {
  * struct rockchip_usb2phy_cfg - usb-phy configuration.
  * @reg: the address offset of grf for usb-phy config.
  * @num_ports: specify how many ports that the phy has.
+ * @phy_tuning: phy default parameters tuning.
  * @clkout_ctl: keep on/turn off output clk of phy.
  * @port_cfgs: usb-phy port configurations.
  * @chg_det: charger detection registers.
@@ -170,6 +173,7 @@ struct rockchip_usb2phy_port_cfg {
 struct rockchip_usb2phy_cfg {
 	unsigned int	reg;
 	unsigned int	num_ports;
+	int (*phy_tuning)(struct rockchip_usb2phy *rphy);
 	struct usb2phy_reg	clkout_ctl;
 	const struct rockchip_usb2phy_port_cfg	port_cfgs[USB2PHY_NUM_PORTS];
 	const struct rockchip_chg_det_reg	chg_det;
@@ -1400,6 +1404,12 @@ static int rockchip_usb2phy_probe(struct platform_device *pdev)
 		goto disable_clks;
 	}
 
+	if (rphy->phy_cfg->phy_tuning) {
+		ret = rphy->phy_cfg->phy_tuning(rphy);
+		if (ret)
+			goto disable_clks;
+	}
+
 	index = 0;
 	for_each_available_child_of_node(np, child_np) {
 		struct rockchip_usb2phy_port *rport = &rphy->ports[index];
@@ -1468,6 +1478,55 @@ static int rockchip_usb2phy_probe(struct platform_device *pdev)
 	return ret;
 }
 
+static int rk3588_usb2phy_tuning(struct rockchip_usb2phy *rphy)
+{
+	int ret;
+	bool usb3otg = false;
+	/*
+	 * utmi_termselect = 1'b1 (en FS terminations)
+	 * utmi_xcvrselect = 2'b01 (FS transceiver)
+	 */
+	int suspend_cfg = 0x14;
+
+	if (rphy->phy_cfg->reg == 0x0000 || rphy->phy_cfg->reg == 0x4000) {
+		/* USB2 config for USB3_0 and USB3_1 */
+		suspend_cfg |= 0x01; /* utmi_opmode = 2'b01 (no-driving) */
+		usb3otg = true;
+	} else if (rphy->phy_cfg->reg == 0x8000 || rphy->phy_cfg->reg == 0xc000) {
+		/* USB2 config for USB2_0 and USB2_1 */
+		suspend_cfg |= 0x00; /* utmi_opmode = 2'b00 (normal) */
+	} else {
+		return -EINVAL;
+	}
+
+	/* Deassert SIDDQ to power on analog block */
+	ret = regmap_write(rphy->grf, 0x0008, GENMASK(29, 29) | 0x0000);
+	if (ret)
+		return ret;
+
+	/* Do reset after exit IDDQ mode */
+	ret = rockchip_usb2phy_reset(rphy);
+	if (ret)
+		return ret;
+
+	/* suspend configuration */
+	ret |= regmap_write(rphy->grf, 0x000c, GENMASK(20, 16) | suspend_cfg);
+
+	/* HS DC Voltage Level Adjustment 4'b1001 : +5.89% */
+	ret |= regmap_write(rphy->grf, 0x0004, GENMASK(27, 24) | 0x0900);
+
+	/* HS Transmitter Pre-Emphasis Current Control 2'b10 : 2x */
+	ret |= regmap_write(rphy->grf, 0x0008, GENMASK(20, 19) | 0x0010);
+
+	if (!usb3otg)
+		return ret;
+
+	/* Pullup iddig pin for USB3_0 OTG mode */
+	ret |= regmap_write(rphy->grf, 0x0010, GENMASK(17, 16) | 0x0003);
+
+	return ret;
+}
+
 static const struct rockchip_usb2phy_cfg rk3228_phy_cfgs[] = {
 	{
 		.reg = 0x760,
@@ -1785,6 +1844,7 @@ static const struct rockchip_usb2phy_cfg rk3588_phy_cfgs[] = {
 	{
 		.reg = 0x0000,
 		.num_ports	= 1,
+		.phy_tuning	= rk3588_usb2phy_tuning,
 		.clkout_ctl	= { 0x0000, 0, 0, 1, 0 },
 		.port_cfgs	= {
 			[USB2PHY_PORT_OTG] = {
@@ -1821,6 +1881,7 @@ static const struct rockchip_usb2phy_cfg rk3588_phy_cfgs[] = {
 	{
 		.reg = 0x4000,
 		.num_ports	= 1,
+		.phy_tuning	= rk3588_usb2phy_tuning,
 		.clkout_ctl	= { 0x0000, 0, 0, 1, 0 },
 		.port_cfgs	= {
 			[USB2PHY_PORT_OTG] = {
@@ -1857,6 +1918,7 @@ static const struct rockchip_usb2phy_cfg rk3588_phy_cfgs[] = {
 	{
 		.reg = 0x8000,
 		.num_ports	= 1,
+		.phy_tuning	= rk3588_usb2phy_tuning,
 		.clkout_ctl	= { 0x0000, 0, 0, 1, 0 },
 		.port_cfgs	= {
 			[USB2PHY_PORT_HOST] = {
@@ -1877,6 +1939,7 @@ static const struct rockchip_usb2phy_cfg rk3588_phy_cfgs[] = {
 	{
 		.reg = 0xc000,
 		.num_ports	= 1,
+		.phy_tuning	= rk3588_usb2phy_tuning,
 		.clkout_ctl	= { 0x0000, 0, 0, 1, 0 },
 		.port_cfgs	= {
 			[USB2PHY_PORT_HOST] = {