usb: dwc3: eic7700: Add EIC7700 USB driver

The EIC7700 instantiates two USB 3.0 DWC3 IPs, each of which is backward
compatible with USB interfaces. It supports Super-speed (5Gb/s), DRD mode,
and compatible with xHCI 1.1, etc. Each of instances supports 16 endpoints
in device's mode and max 64 devices in host's mode.

This module needs to interact with the NOC via the AXI master bus, thus
requiring some HSP configuration operations to achieve this. Ops include
bus filter, pm signal or status to usb bus and so on.

Acked-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Signed-off-by: Senchuan Zhang <zhangsenchuan@eswincomputing.com>
Signed-off-by: Hang Cao <caohang@eswincomputing.com>
Link: https://patch.msgid.link/20251112055346.1655-1-caohang@eswincomputing.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: Hang Cao

drivers/usb/dwc3/dwc3-generic-plat.c

@@ -10,8 +10,16 @@
 #include <linux/clk.h>
 #include <linux/platform_device.h>
 #include <linux/reset.h>
+#include <linux/regmap.h>
+#include <linux/mfd/syscon.h>
 #include "glue.h"
 
+#define EIC7700_HSP_BUS_FILTER_EN	BIT(0)
+#define EIC7700_HSP_BUS_CLKEN_GM	BIT(9)
+#define EIC7700_HSP_BUS_CLKEN_GS	BIT(16)
+#define EIC7700_HSP_AXI_LP_XM_CSYSREQ	BIT(0)
+#define EIC7700_HSP_AXI_LP_XS_CSYSREQ	BIT(16)
+
 struct dwc3_generic {
 	struct device		*dev;
 	struct dwc3		dwc;
@@ -20,16 +28,50 @@ struct dwc3_generic {
 	struct reset_control	*resets;
 };
 
+struct dwc3_generic_config {
+	int (*init)(struct dwc3_generic *dwc3g);
+	struct dwc3_properties properties;
+};
+
 #define to_dwc3_generic(d) container_of((d), struct dwc3_generic, dwc)
 
 static void dwc3_generic_reset_control_assert(void *data)
 {
 	reset_control_assert(data);
 }
 
+static int dwc3_eic7700_init(struct dwc3_generic *dwc3g)
+{
+	struct device *dev = dwc3g->dev;
+	struct regmap *regmap;
+	u32 hsp_usb_axi_lp;
+	u32 hsp_usb_bus;
+	u32 args[2];
+	u32 val;
+
+	regmap = syscon_regmap_lookup_by_phandle_args(dev->of_node,
+						      "eswin,hsp-sp-csr",
+						      ARRAY_SIZE(args), args);
+	if (IS_ERR(regmap)) {
+		dev_err(dev, "No hsp-sp-csr phandle specified\n");
+		return PTR_ERR(regmap);
+	}
+
+	hsp_usb_bus       = args[0];
+	hsp_usb_axi_lp    = args[1];
+
+	regmap_read(regmap, hsp_usb_bus, &val);
+	regmap_write(regmap, hsp_usb_bus, val | EIC7700_HSP_BUS_FILTER_EN |
+		     EIC7700_HSP_BUS_CLKEN_GM | EIC7700_HSP_BUS_CLKEN_GS);
+
+	regmap_write(regmap, hsp_usb_axi_lp, EIC7700_HSP_AXI_LP_XM_CSYSREQ |
+		     EIC7700_HSP_AXI_LP_XS_CSYSREQ);
+	return 0;
+}
+
 static int dwc3_generic_probe(struct platform_device *pdev)
 {
-	const struct dwc3_properties *properties;
+	const struct dwc3_generic_config *plat_config;
 	struct dwc3_probe_data probe_data = {};
 	struct device *dev = &pdev->dev;
 	struct dwc3_generic *dwc3g;
@@ -77,12 +119,21 @@ static int dwc3_generic_probe(struct platform_device *pdev)
 	probe_data.res = res;
 	probe_data.ignore_clocks_and_resets = true;
 
-	properties = of_device_get_match_data(dev);
-	if (properties)
-		probe_data.properties = *properties;
-	else
+	plat_config = of_device_get_match_data(dev);
+	if (!plat_config) {
 		probe_data.properties = DWC3_DEFAULT_PROPERTIES;
+		goto core_probe;
+	}
 
+	probe_data.properties = plat_config->properties;
+	if (plat_config->init) {
+		ret = plat_config->init(dwc3g);
+		if (ret)
+			return dev_err_probe(dev, ret,
+					     "failed to init platform\n");
+	}
+
+core_probe:
 	ret = dwc3_core_probe(&probe_data);
 	if (ret)
 		return dev_err_probe(dev, ret, "failed to register DWC3 Core\n");
@@ -150,13 +201,19 @@ static const struct dev_pm_ops dwc3_generic_dev_pm_ops = {
 		       dwc3_generic_runtime_idle)
 };
 
-static const struct dwc3_properties fsl_ls1028_dwc3 = {
-	.gsbuscfg0_reqinfo = 0x2222,
+static const struct dwc3_generic_config fsl_ls1028_dwc3 = {
+	.properties.gsbuscfg0_reqinfo = 0x2222,
+};
+
+static const struct dwc3_generic_config eic7700_dwc3 =  {
+	.init = dwc3_eic7700_init,
+	.properties = DWC3_DEFAULT_PROPERTIES,
 };
 
 static const struct of_device_id dwc3_generic_of_match[] = {
 	{ .compatible = "spacemit,k1-dwc3", },
 	{ .compatible = "fsl,ls1028a-dwc3", &fsl_ls1028_dwc3},
+	{ .compatible = "eswin,eic7700-dwc3", &eic7700_dwc3},
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, dwc3_generic_of_match);